Onno (VK6FLAB)

Foundations of Amateur Radio

The building blocks for Amateur Radio, one concept at a time
Foundations of Amateur Radio


Starting in the wonderful hobby of Amateur or HAM Radio can be daunting and challenging but can be very rewarding. Every week I look at a different aspect of the hobby, how you might fit in and get the very best from the 1000 hobbies that Amateur Radio represents. Note that this podcast started in 2011 as "What use is an F-call?".

Link: podcasts.itmaze.com.au/


Listening from the ground up

Mar 28, 2020 293


Foundations of Amateur Radio

When I started learning about antennas I was told height is might. The higher the better. For many years I've followed that advice and like a good little parrot I've dispensed that advice. Turns out that as is usual in our hobby, that's not the whole story.

I first came across a ground based antenna with a BOG, that's a Beverage On Ground antenna. It's essentially a long length of coax that's pointed at what you want to hear. You can either terminate the end, or not, different effects result with plenty of discussion about directivity, angles, lobes and the like.

One of the things you'll notice with you use a Beverage antenna is that it's quiet. All signals are reduced in strength, but that also means that noise is reduced. Turns out that this pays off and you hear stuff that you've not heard before. Excellent for a field day or if you want to hear some serious DX stations.

There's plenty of stuff that's not nice about a Beverage antenna. For one, it's highly directional, it takes up lots of space and if you want to listen in another direction, you'll either build a second or third and switch between them. That, or you'll be rolling up and laying out the coax to point at a new DX entity.

You also cannot transmit with a Beverage antenna. While we're on the subject, often a beverage can be combined with a vertical, one for receive, the other for transmit. It's one of the projects that lying in my to-do pile. I've even got a remote controlled coax switch, but I'm still figuring out how to make my FT-857d do the switching.

I could stop there, but I came across another idea a couple of weeks ago. At the time I was being introduced to the local emergency communications team. They showed me their HF stand-by gear. Long piece of wire that you could chuck out on the ground and make contact. As a good little amateur I remember thinking to myself, these poor people they have a lot to learn. I'm glad I'm an eager apprentice in learning the art of keeping my big mouth shut.

During F-troop, a weekly net for new and returning amateurs, you'll find details on vk6flab.com, another amateur was talking about putting a wire near the ground, like about a foot off the turf with great results.

I tried it on the weekend with a friend. We were out camping for a local amateur contest, miles from anywhere and anyone and I recalled the emergency communications people and the story during F-troop. We had some time to play, so we started with a long-wire, actually, pretty-much a wire dipole on the ground. Plugged it in, turned on the radio, magic. Same kind of sound effect as a Beverage antenna. Nice and quiet, good signals to be heard. We turned the whole contraption 90 degrees, no difference. Since then I've learned that it's pretty much omni directional and unlike a Beverage antenna, you can use it to transmit.

Of course it's not going to act in quite the same way as a dipole high in the air, and that's pretty obvious, since it's not in the air. It'll give you communications that are called NVIS, or Near Vertical Incident Skywave, essentially stuff that goes straight up and comes down, stations up to about 400 km or so away. For scale, that's enough to cover all of Holland. In Australia it's enough to cover the state of Victoria, or the width of the UK, and most of the width of the State of New York.

Before you get all huffy and point out that this is not a great DX antenna I'll beat you to it and tell you that this is not a great DX antenna. It's not meant to be. Nor is it intended to be an instruction on what antenna to build next. This is purely intended to illustrate that antennas come in all manner of shapes and sizes and there is lots to be learnt from trial and error.

I know that this is a "compromise" antenna. Guess what, so is every other antenna. Today the compromise is that we don't need any poles, trees or unsuspecting human support structures to keep an antenna in the air. You can essentially try this one for free at any time, on your own, on the beach, in a park or on the side of a mountain.

Another great use is to talk to your friends who live in the same city on HF. I have no doubt you could even manage some FT8 contacts using this antenna.

Next time someone tells you to put your antenna in the air, ask them who they want to talk to. If it's locals, then there is absolutely no need at all. As for mastering the art of keeping my big mouth shut, we'll see.

I'll leave you with this. It's not the answer that's important, it's the question, for everything else there's experimentation.

I'm Onno VK6FLAB

What level of preparedness are you at?

Mar 21, 2020 347


Foundations of Amateur Radio

An often repeated statement about the purpose of our hobby is related to emergency preparedness. The various peak bodies around the world devote plenty of resources to the concept, with helpful examples, umbrella organisations, training, coordinators, grants and funding, photo-opportunities and all the other trimmings that come from the idea that you and I are going to be of assistance in the case of some or other emergency.

Looking up the various emergency coordination groups is a disappointing experience. From broken web-sites with non-existent pages to latest news that's over two years old, through to the latest sausage sizzle and fun-run. Entreaties to make sure that you have your current Membership ID card, otherwise you won't be covered for insurance purposes. As I said, all the trimmings with lots of evidence of paper pushing and little or no evidence of actual preparedness, let alone public information that might help any new or old radio amateur become prepared.

Back to the topic at hand and leaving aside the nature of the emergency for a moment, given that the response for a bush-fire, a cyclone, flood or pestilence is likely to be different.

Let's look at the things we have direct control over.

If you have at any time taken your radio out of the shack and carried it into a paddock, connected it to an antenna, fired it up and made a contact, you're well ahead of the curve.

There are plenty of amateurs who have never ever considered what going field-portable might look like, let alone tried it. That's fine if you live in a bunker, have independent power and are able to withstand all manner of disaster scenarios, but realistically it likely means that your emergency assistance will be of the kind that's outside the emergency zone. Helpful to be sure, but there's plenty of those stations to be found - unless the issue is global, in which case we have a completely different set of problems, pandemic, anyone, anyone?

Let's focus on the other side of the fence.

You're in an emergency zone. Doesn't matter what kind of emergency. Communications are limited or overwhelmed, information is restricted, messaging is hampered and you're a radio amateur with a working radio. If all goes well you should be able to help.

So what does a working radio look like and what does helping mean?

First thing to think of is power. Have you got a battery? Is it charged? When was the last time you tested it? How long has it been sitting on the shelf? Did it discharge in the meantime? What about a charger? Have you got a generator? What about fuel and oil? What about spare parts? Have you got something else, like a solar panel, a wind generator or a water turbine? What about a push-bike with a dynamo attached? How long does your radio run on a battery and at which transmitter power level is that?

After thoroughly investigating power, what does your actual emergency station look like? Will it be used for voice communication, or will it be used as a digital gateway? Can you use it to send rudimentary messages, or can it be used as an internet gateway for a local community?

What bands are you planning to operate on? Do you have an antenna? What happens if your current antenna is taken out by a fire, lighting strike or something else? When was it last tested? Do you have a back-up antenna? Have you actually used this antenna? Does it have all the right connectors and are they with the antenna?

So, pretend that you got all that right. What about you? Have you got spare clothes? Food? Shelter? Medication? What about Personal Protective Equipment, masks, gloves, what-ever? What about ancillary items like pen and paper? Do you have power for the laptop that's being used to create the digital mode messages?

Note that I've not said a word about the usefulness of any of this. This is the base level of preparedness just so you can actually look yourself in the mirror and say that you have at least got a level of ability to be of assistance in the case of an emergency.

You can of course argue that you should hook up with the local emergency services and offer your skills as a radio amateur. That's helpful, but what if you cannot actually go to the muster point? How does that help?

Now lets pretend that you actually have done all this. When was the last time you tested it?

What does the actual helping look like?

Have you ever attempted to pass emergency messages? What about messages that must be transferred absolutely 100% correctly, think medication dosages? Who did you pass them to? When was the last time you did a regional emergency simulation between your amateur friends? How often do you do this? Once a decade, or more often than that? What if the local repeater isn't working? What about in your club or your local neighbourhood? Do your neighbours even know you exist?

The point of all of this is to reveal that the level of emergency preparedness for radio amateurs is in my opinion spotty at best. If you disagree with me because you are prepared I'd like to ask if you helped prepare your local amateur community and the wider community around it? I don't doubt that there are individuals, even groups who are prepared, but I suspect that they are far and few between.

When was the last time you actually went into the field for a week and played radio, for real, battery only, limited resources, no outside help?

I'd love to believe that this is universal, but you and I both know that there is plenty more to be done. How realistic is your emergency preparedness and what are you going to do about it?

I'm Onno VK6FLAB

On the shoulders of giants we stand.

Mar 14, 2020 253


Foundations of Amateur Radio

One of the things I love most about this hobby is the ability to randomly dart off into any related direction and learn new stuff. For example, the names Nikola, Guglielmo, Heinrich and Edwin emblazoned on a t-shirt sent to me by a very appreciative listener Jack KI4KEP, started an exploration into the deeds and misdeeds of the people behind those names.

The first three might be somewhat familiar, Nikola Tesla whom we have to thank for inventions like Alternating Current, the Tesla coil, wireless power, radio remote control and many others. The Tesla company is named as a tribute to him. The magnetic flux density uses the letter T as its symbol and its called the Tesla.

As a side note, if you've ever struggled to decide if a symbol needs to be a capital letter or not, like say the V for volt, the A for ampere, the O for ohm, the m for meter, the s in second or the K in kelvin, you just need to remember that if the unit is named after a person, the symbol needs to be a capital letter. That does assume that you know that the unit is named after an actual person, like say the Earl of Sandwich.

Name two in our list, Guglielmo Marconi is the person whom we can thank for the practical development of radio communication, using improved spark-gap transmitters, the development and commercialisation of long-distance radio transmissions and his association with many other services such as a transatlantic radio-telegraph service, providing communications to shipping such as Jack Phillips and Harold Bride who were employed by the Marconi International Marine Communication Company to act as radio operators on the RMS Titanic on its fateful voyage.

Our third name, Heinrich comes into sharp focus when I add his surname, Hertz. His name continues on in our day-to-day language and Heinrich Hertz is responsible for validating many of the underlying principles of our hobby. Using a spark-gap transmitter he was the first to conclusively prove the existence of electromagnetic waves which were predicted by James Clerk Maxwell. He also came up with the parabolic antenna, the dipole antenna, measurement of electric field intensity, electromagnetic waves and many other experiments. If you've ever seen a bullet hole in glass, you've seen a Hertzian cone.

The last name had me stumped. It took a question to learn that Edwin shares a name with a famous cyclist and a famous astronaut, namely Armstrong. Edwin Howard Armstrong has been called "the most prolific and influential inventor in radio history".

If you're like me you may not have heard of Edwin Armstrong. You might be surprised to learn that he's responsible for the regenerative circuit, the super-heterodyne circuit and while he was working on defending his invention against a claim made by a patent attorney he stumbled on the super-regeneration circuit. If you're a radio amateur, you'll likely have heard those terms, if not, they're electronic circuits that make radio receivers more sensitive which forms the basis of many radios in use today. My Yaesu FT-857d is a super-heterodyne radio for example.

It doesn't stop there. The biggest claim to fame that Edwin Armstrong brings to the table is the invention of FM radio. It took many years and a protracted lawsuit that lasted until almost a year after he died to finally have Armstrong formally established as the inventor of FM.

Not for a minute will I suggest that my exploration was comprehensive or in-depth, but it made my day when I put on a t-shirt with the names of those inventors who made it possible for me to be here and share this with you today.

On the shoulders of giants wearing a t-shirt with their names I stand.

I'm Onno VK6FLAB

All bands + All modes + All countries

Mar 7, 2020 246


Foundations of Amateur Radio

A regular lament is the lack of things to do in our hobby. I know, it's foreign to me, but there are plenty of amateurs who express frustration at the lack of activity, no contacts, nothing new, no challenges.

For my poison, I started the process of contacting 100 different countries using 5 Watts. I've been at it for a number of years and truth be told, since my latest domestic move, over two years ago now, my efforts have been put on hold. Not because I didn't want to, but because I was getting annoyed with having to leave my home and wanting desperately to have a functional shack at home. As you might know, that's a project that's still in hand and thanks to some magnificent assistance from various places, I'm still making progress.

That said, your perspective might be dulled by the notion that this pretty much concludes the on-air activity possibilities that exist. Within my own license class, until recently, I was permitted to use voice modes like SSB, AM and FM and I was permitted to use hand-keyed Morse. I have access to 10 Watts and am currently allowed to use six different amateur bands, namely 80m, 40m, 15m, 10m, 2m and 70cm. So together with the four modes, I'd be able to make 24 different contacts to 100 different countries, that's 2400 different combinations.

Of course there are more than 100 countries, that is, DXCC entities. The 2018 list has 340 of them, so that's over 8-thousand different options for getting on air and making noise.

Last year all that changed. The local regulator in Australia, the ACMA decreed that all amateurs in Australia were permitted to use all modes.

It's taken a little while for that to sink in. Specifically what it means for me.

A quick search reveals that there are at least 60 different digital modes, think RTTY, Olivia, PSK31, etc. In addition to those, there's a plethora of other modes like IRLP, AllStar Link, EchoLink, CODEC2 and Brandmeister.

So conservatively I'm going to estimate that I now have got access to over a hundred different modes, across six bands with 340 countries, that's over 200-thousand different options for making a contact.

Of course it's unlikely that I'll make a contact between say Belize V3A and Perth VK6 on 2m using Olivia, but even if we limit our calculation to HF, we still have at least 136-thousand opportunities for adding something interesting to your logbook.

I've been hunting for a canonical list of all the various amateur modes and the tools needed to make and receive them. No doubt that will take me some time. I'll be documenting it on the projects page on vk6flab.com if you want to follow along. Speaking of which, you'll also find past episodes of this podcast there.

I suppose I should start by converting my current efforts into some pretty pictures that show what I've been up to so far, but that's a mapping exercise that I'll have to add to my to-do list, since I'm guessing it involves learning how to use some fun mapping tools.

If 136-thousand opportunities isn't enough, you can also add grid-squares, large and small, different prefectures in Japan, provinces in the Netherlands, CQ zones across the world or ITU areas, prefixes and operating modes.

Clearly there's plenty to do and see.

I wonder if there's an award for all modes all bands all countries and I wonder what happens if someone invents a new mode?

I'm Onno VK6FLAB

The impersonal nature of digital and other myths

Feb 29, 2020 319


Foundations of Amateur Radio

The other day I bumped into a concept that I've heard repeated before. The so-called "impersonal nature" of digital modes.

There's this idea that any communication that isn't using voice, is devoid of the human touch. Often this assertion is specifically made in relation to modern digital modes like JT65 and FT8. As an aside, I've never heard it in relation to other digital amateur modes like slow-scan television, RTTY or PSK31.

In the early 1900's when amateur radio was beginning to be a thing, the means of communication was Morse Code. With beeps across the globe contacts were made between amateur stations. With every incoming dit and dah, letters were received, words constructed and meaning derived. This is long distance communication in its early stages.

Each amateur was said to have a fist, their particular rhythm of touching the key. Across multiple stations it was possible for an experienced operator to distinguish between two amateurs based on how they were sending Morse Code. I can confirm that if you've ever had the privilege of hearing lots of amateurs clamour in a so-called pile-up, you can hear for yourself that different stations sound different, even if they're all sending Morse Code.

So on the one hand we have this deeply inhuman means of communications like Morse Code which is by the language we use considered to be made by humans, personalised with a fist. On the other hand we have a deeply technical mode like FT8 which isn't.

During the week I was discussing this change of perception during a haircut. I pointed out that this happens everywhere. For example, in the hairdressing profession an electric clipper might have been seen as impersonal when it was invented in 1921. Today it makes quick work of a Number 1 cut. In mobile phone communication an SMS was seen as impersonal with voice preferred, but today the world would look quite different without the 5 billion messaging mobile phone subscribers. In 2013 it was estimated that there were 8 trillion SMS messages, and 10 trillion other smart phone messages. As you might realise, behind each of those messages is a human, well, apart from the SPAM and the computer notifications, but even those are programmed by a human.

So what makes the difference between Morse Code and FT8? Why is an SMS impersonal in 1992, but preferred by most today?

I'd hazard a guess and state that the experience of the person making the statement has a lot to say about their perception of the nature of the medium.

My typing away at a keyboard and seeing words appear on my screen might not appeal to someone who chased a turkey around the yard in search of a quill, but then electricity might also be surprising.

It's interesting to me that PSK31, something that's not particularly thought of as being impersonal, was introduced to the amateur radio community in December 1998 by Peter G3PLX. The first Weak Signal modes, commonly known as WSJT modes, were introduced in 2001 by Joe K1JT, only three years later. JT65 came around in 2003. We have this situation where PSK31 is not impersonal, but JT65, which is five years younger, is considered impersonal and the popular mode FT8, which is an extension of JT65 is said to be the end of the hobby.

If hyperbole would relate to truth, the end of our hobby in sight, we should all get rid of our radios and hand back our licenses.

Perhaps we should take a step back and notice that behind every FT8 station, behind every voice-call, behind every amateur transmitter is at some point a human with a license. If we're splitting hairs, then a local automatic voice repeater must be the height of impersonal.

The other thing I'd like to point out is that how you perceive the use of a particular mode is also important. If you think of FT8 as having a personal beacon in your shack that uses your radio and your antenna to measure how well your signal is heard across the globe, you might just start enjoying this so-called impersonal mode.

One of my friends, Wally VK6YS, now silent key, told a story where he was driving down the highway to meet his friend. They were chatting away using Morse Code, Wally in his car, the friend in his shack. Once Wally arrived the friend wanted to see how Wally was able to send Morse Code whilst driving and could he please see his Morse key? Wally confessed to having whistled into his microphone to make the contact, since he didn't have a Morse key in his car. According to Wally, his friend was off the air for months in disgust.

I should mention that my Number 1 haircut looks great, if only for the fact that it allowed me to spend some quality time discussing and contemplating the nature of the hobby that I love.

I'm Onno VK6FLAB

The chicken and the egg, which comes first, the antenna or the radio?

Feb 22, 2020 269


Foundations of Amateur Radio

In my day to day activities as a radio amateur I come in contact with people across all parts of their amateur journey. Some who don't yet know that they're amateurs, through to those who've just passed their test and are waiting for their callsign. Then there are those who have been amateurs for a while, experimented a bit and have settled down into the comfort of being a member of an active community. Stretch that further and I also spend regular quality time with amateurs who have been licensed longer than I've been alive.

Recently I received an email from a freshly minted amateur. Just like me, still pretty much wet behind the ears, keen as mustard, trying very hard to figure out what to do next and where to go.

The basic gist of the email from this amateur was that they didn't know what kind of antenna they could erect at their home and failing that, couldn't decide on what radio to acquire to match the antenna that they hadn't decided on, not to mention that the antenna needed to match the radio that didn't yet exist.

If you've been around this community for a while you might recognise the chicken and the egg, which comes first, the antenna or the radio?

The answer is obvious, hidden in plain sight, easy to deduce, simple to understand, and completely useless.

Let me help you with the answer: It depends.

If that didn't test your patience, even if you've been an amateur for longer than my parents have been alive, you'll know that this is an unanswerable question.

So how do you break the egg and get started?


Start somewhere.

As it happens I have a recommendation. It's cheap, simple and it will get your feet wet sooner rather than later. My recommendation is neither, or both, depending on your perspective. I promise, I'll get to the point shortly. The reason I'm making it last and savouring the point, some might say, belabouring it, is because it's one that happens over and over again, day in, day out, year in, year out.

My recommendation is that you spend $25 on an RTL-SDR dongle and hunt around your home for a piece of wire. That's it.

If you're not familiar with an RTL-SDR dongle, it's essentially a USB thumb-drive sized device that plugs into the nearest computer and paired with the correct software it has access to many if not all of the frequencies that you as an amateur are allowed to play with.

Given that it's a receiver, the antenna doesn't really matter all that much, at least not initially, so any piece of conductive wire will suit. Most dongles even come with an antenna of sorts, so you can get started straight away.

Resources associated with this podcast are on the vk6flab.com website where I've also collected a few links under F-troop to get you on your way with an RTL-SDR dongle.

The purist radio amateurs will likely arc up at this point and mention that this isn't real amateur radio, to which I can only say: Bah Humbug. Radio is about receiving as much as it is about transmitting. Any fool with two bits of wire can transmit, but it takes finesse to receive, so start there.

There are other benefits from going this way. Other than ease of entry, that's another way of saying - cheap - you can easily spot where and when there is activity. You can use all the traditional modes like CW, SSB, AM and FM, but you can also play with all of the new modes like WSPR, FT8, JT65 and investigate some of the other modes like RTTY, PSK31, Olivia, SSTV and others.

All this will help you have a better idea of the landscape you're stepping into without a major purchase.

To really set a cat among the pigeons, I'm also looking into a Raspberry Pi based transmitter, rpitx by Evariste F5OEO. When that bears fruit I'll let you know. In the mean time, play, learn, listen, experiment. No need to spend hundreds or thousands of dollars while you're still unsure.

Even if you already have a lovely amateur station, an RTL-SDR dongle is worth every cent and then some.

I'm Onno VK6FLAB

Exploring an understanding of filters and circuits.

Feb 15, 2020 356


Foundations of Amateur Radio

Every person is the product of their environment. Unsurprisingly this is even true for radio amateurs. That's not too say that we can't break our mould, but it takes effort. I grew up around technology in the 1980's. As a result I'm familiar with 8-bit microprocessors like the Motorola 6502 which featured heavily at the time. I tend to think in terms of the presence or absence of a signal, rather than the intricacies of circuits and components.

As a child of my time, I'm not particularly familiar with the punch card or paper tape, or core memory, or valves, 386 machine code or what's in an FPGA. As a direct result of my age, my knowledge and understanding of circuits is sparse at best. I understand basic components like resisters and capacitors in a DC setting, Ohms Law and the fun you can have with a battery, a few resistors, diodes and an LED light.

As a radio amateur I've been introduced to how some things work differently in an AC circuit, like an antenna and a feed-line.

Until very recently my knowledge about filters was based on what I'd read. I know that there is fun to be had with coax and stubs and other cute things, but how and why they work eluded me. Today I'm a step closer.

Before I dig in and share some of what I've learnt, let's have a quick look at what a filter is and does. You'll have likely heard of high-pass and low-pass filters. You might have heard of band-pass and band-stop filters.

If you think of a high-pass filter as a device that lets through high frequencies and a low-pass filter as a device that lets through low frequencies, we're already well on our way. If you put a high-pass filter together with a low-pass filter, you end up with a range of frequencies that doesn't pass, known as a band-stop filter.

Similarly, if you tweak the frequencies that pass just so, you can combine a high-pass and a low-pass filter to make a band-pass filter.

Let me illustrate.

Imagine a 15m band-pass filter. It allows all frequencies in the 15m amateur band through, but blocks everything else. You could construct such a thing from a high-pass filter that allows 15m and above through combined with a low-pass filter that allows 15m and below through. Everything below 15m is stopped by the high-pass filter and everything above 15m is stopped by the low-pass filter. The gap between the overlap of the high-pass and low-pass filters is what creates a space where the 15m band gets through.

If you move things around a little, the same can be constructed to make a 15m band-stop filter. Something that lets anything through, except a 15m amateur signal. To make such a gadget would require a low-pass filter that allows everything below 15m combined with a high-pass filter that lets everything above 15m through.

So, if you can construct a high-pass filter and a low-pass filter, you can pretty much create any combination and allow or stop specific frequency ranges.

If you're wondering why this might be useful, think about a contest. Two radios in the same shack. One transmitting on 15m and one on 40m. These two bands, one at 21 MHz and one at 7 MHz are third harmonics to each other. This means essentially that a radio on 40m affects one on 15m and vice-versa. If you had a set of filters that stopped 15m and passed 40m on one transceiver and a set of filters that stopped 40m and passed 15m on the other, both of you would be much happier.

You don't need to do contesting to benefit from a filter. If you use an RTL-SDR dongle, it's affected by nearby strong signals, like say a local radio or television station. That's fine if that's what you're trying to hear, but not so much if you're trying to hear something else. Filters can help to make your life better.

Now, to round this off at a suitable point, you can think of an inductor as device that lets low frequencies through but blocks high frequencies. Similarly, a capacitor is a device that blocks low frequencies but lets high frequencies through. So, it's fair to think of an inductor as a low-pass filter and a capacitor as a high-pass filter. The symbol for a capacitor is the letter C (Charlie) and for an inductor it's the letter L (Lima).

You could make a circuit that either directly blocks from a certain frequency, or one that lets it through, but sends it to ground. This gives you two designs for a low pass filter one using an inductor or an RL circuit and one using a capacitor or an RC circuit. Similarly you can create a high-pass filter using either an inductor or a capacitor. That gives you four designs for two filters.

Each of these can be combined to create band-pass and band-stop filters.

The maths behind it isn't particularly daunting with basic high-school maths and if you want to see it happen before your eyes, check out the "Organic Chemistry Tutor" on YouTube. The play list you're looking for is cleverly disguised as "Electronic Circuits".

As a direct result, I started hunting for breadboards, but it turns out that you can simulate these circuits online using any number of simulators. Of course there's going to be a gap between simulation and reality, but that's when you get out your soldering iron.

Remember, if you smell chicken, you're holding it wrong.

I'm Onno VK6FLAB

How I care for my connectors

Feb 8, 2020 242


Foundations of Amateur Radio

If you've ever found yourself in the position of attempting to screw a PL259 into an SO239, or an N-type plug into an N-type socket you'll have likely come across the situation where the thread doesn't quite fit. If it does, you might have issues attempting to undo the connection, even if you didn't particularly do anything strenuous in relation to mating the two in the first place.

This kind of situation happens to me more than I think is reasonable. It happens on cheap connectors, on expensive ones, on the back of radio gear, on adaptors, patch leads and the like.

Initially I put this down to cheap vs. expensive, but that really doesn't add up if you're attempting to connect an expensive plug into an expensive radio.

If you're into machining you'll know about swarf. If not, think metallic dust. Of course it doesn't have to be metallic, it could be a single grain of sand, or it could be a slightly damaged thread.

A couple of months ago I went on the hunt for a tap and die set that would solve this issue once and for all. If you're not familiar with the terms, a tap is like a long bolt with a square head and a die is like a thick washer with holes cut out.

In addition to being hardened, they each have cutting edges, which allows these two tools to do their job, the job of cutting threads.

Normally you'd use a tap to make a thread into a hole that you've drilled. You'd use a die to make a thread onto a rod that you have. There's lots of technique associated with this, cutting fluids, alignment, pressure and the like. Plenty of relaxing YouTube videos around - which is how I came upon this idea in the first place.

You can also use a tap or a die to cut across an existing thread and you can do this with connectors.

A die, threaded over a socket, will clean up the socket threads. Similarly a tap screwed into a plug will clean up the plug thread. There's a disclaimer coming for that last point, but stick around.

Trying to find a tap and die to match can be a challenge. The PL259, SO239 and N-type connectors are all 5/8th size threads. They're 24 turns per inch, and also known as UNEF (Uniform November Echo Foxtrot) threads, or Unified Extra Fine.

So if you start on your hunt, you'll be looking for 5/8th, 24 TPI, UNEF taps and dies.

I found mine online at $15 or so from a US supplier. Got to me in about a week.

When they arrived I immediately set about cleaning up all my sockets. This was amazing, all of a sudden stuff started fitting well. Unfortunately I couldn't use the tap. The centre hole in a standard tap isn't big enough for the pin of a PL259, let alone an N-type connector, but a friend of a friend has access to machine tools and made the centre hole bigger. Word of warning, this is hardened steel. A hand-drill won't cut it.

I must mention that this won't allow you to use the tap inside an N-type plug, but you can use a die on the socket.

I'll also point out that if you need to use a tap wrench or a die holder, you're doing it wrong. We're cleaning up the thread, not making a new one. If you need extra force the most likely scenario is that you've cross threaded the tool onto the connector.

Of course if you've got a completely stuffed connector thread, then these tools can help, but you might want to consider replacing the connector.

My tap and die live in my go-kit right next to the coax adaptors. On my next field-day I won't be having to deal with poor connections, nor will I have to worry about unscrewing them after the event.

A tap and die, great simple tools to fix a recurring issue.

I'm Onno VK6FLAB

How I host a weekly amateur radio net for new and returning amateurs

Feb 1, 2020 260


Foundations of Amateur Radio

If you've ever had the pleasure or misfortune to hear an on-air net, you might have considered, however briefly, how that net came to be, how it's run and what's involved behind the scenes to make it happen.

I host a weekly net called "F-troop". It's been running every week since the 12th of June in 2011. Since then I've made over 5000 contacts with stations scattered all over the globe. A typical net has about ten people, but depending on the weather, what's on TV or if people had a hard Friday night that number fluctuates. The biggest was about 40, the smallest just two.

At this point I could tell you that the infrastructure to make this happen, the preparation, management processes, network and marketing are what take up the bulk of my week. I mean, there might be a weekly stand-up between stakeholders on a Wednesday, a plan for the content, what to discuss, you know, the typical.

If I told you that, I'd be lying.

The reality is that F-troop is an organic animal. I generally get to my radio a couple of minutes before we start, midnight UTC, switch on, kerplunk the local repeater and wait for the clock to tick over.

I then launch into my opening spiel, something along the lines of: "Hi folks, it's me, it's F-troop, who's awake?"

After taking a few calls and logging them, I'll circulate through, call for more people, rinse and repeat.

There are two invisible things happening, one required, the other I do because I'm a computer geek. The required activity is logging. I chose to log in an online spreadsheet. It's helpful because it makes for a single place where all contacts are stored and it allows for others to host the net if I happen to fall off the air, either by being somewhere else, like a holiday every decade or so, or because my radio isn't being cooperative.

The other thing that logging gives you is a memory. I generally recall a person's name from their callsign, but if you listen closely you'll notice that every now and again I'll extend my babble so I can search for a callsign and appear not to be suffering from memory loss.

The other thing that happens is that I update the website. I'll be merrily adding articles from emails or discussion as it's happening. If someone mentions a product or a website, a callsign or a project, I'll often be searching for it in real time and adding it as a post to the F-troop website. That way people who want to refer back at a later time, that includes me, can search and find the thing that someone showed us.

As simple or as complex as that sounds, depending on your level of experience, it's really not rocket science. You can do this with pen and paper. I know, I've done it, standing in a car-park with a notepad, whilst dodging rain showers and preparing for a field-day. It's fun to test your skill and to get out of your comfort zone every now and again.

I should interrupt this story for a word from our sponsors. Don't have a kitten, we're not talking about advertising, we're talking about repeater and network operators who graciously give of their time and resources to link the main F-troop repeater to others around the world. The network of AllStar, Echolink, IRLP and IRN radios that carry F-troop is astonishing to me. We have regular participants all over Australia, the United States and the United Kingdom. There have been contacts with stations in Asia and Europe.

For that to happen I don't do a single thing. Well, technically I let repeater operators know I exist and when it breaks, but that's pretty much the sum total of my efforts.

Why am I telling you this?

Last week it broke. My radio was acting up and someone commented on that. I handed over the reigns and let them at it. They were very unsure. I let them know that F-troop is for beginners. It's expected that people are going to make a mistake, I know I do, plenty of times.

It occurred to me afterwards that hosting a net can be scary. If you have no idea what's involved, how to make it happen, what to do, then hosting must be immensely daunting.

I hope that sharing how I do this will give you the confidence to host your own net in your own community. Perhaps you can tell me more about it, or come and visit F-troop. Saturday morning at midnight UTC. If you want I'll even help you host it.

I'm Onno VK6FLAB

Is this frequency in use and other lies we tell ourselves.

Jan 25, 2020 336


Foundations of Amateur Radio

When you switch your radio on to start a radio fishing expedition you join all the other spectrum users across the planet. To be fair, you'll likely only become aware of some of those for the time that your radio is switched on, even if there are thousands around.

One of the ways you can find other users is by ditting out "QRL?" in Morse or saying "Is this frequency in use?" into your microphone.

This simple courtesy of checking to see if the frequency you're on is actually being used by someone, is part of your license. You're taught to do this and it's expected.

What's not clear is what happens next.

It's simple if you hear a callsign, or a "yes", but what if you hear nothing?

Sometimes nothing means exactly that, there's nobody on the frequency, but that's not always the case. There's plenty of opportunity for the frequency to be in use and you still not getting a response back.

Let's imagine for a moment that the frequency you're on is in use by two stations talking to each other. You come on frequency, hear nothing and ask if the frequency is in use. You hear nothing. You try again, still nothing. You start calling CQ. Moments later, you get an earful from some random station.

Sound familiar? If it doesn't, you'll need to spend more time on-air. I can guarantee that you'll experience this in your amateur adventures, much more than once.

How does this happen? You did everything right.

Imagine two stations, let's call them Amanda VK4FRST and Marc VK3OHM, having a conversation, a QSO. They're discussing the ins- and outs of the WIA awards system and having a grand old time.

You turn your radio on, happen to tune to the same frequency as their QSO and after listening to nothing for a bit, you call "Is this frequency in use?". You still hear nothing so you try again: "Is this frequency in use? VK6FLAB". Still nothing. You call "Nothing heard." and start calling CQ.

You're on one side of the country, Amanda and Marc are on the other side. They cannot hear you and you cannot hear them. Then the sun moves a bit and all of a sudden your CQ is all over their discussion. Unhappy people on both sides of the country.

There are six paths to consider here. The one between you and Amanda, and the reverse. Similarly the path between you and Marc and that reverse. If you ask for frequency in-use, neither Amanda, nor Marc can hear you. Similarly, you cannot hear either Amanda or Marc. You should also take a moment to consider the path between Amanda and Marc and vice-versa. They might have a really great 5 and 9 conversation, or they might be struggling along with a 3 and 2.

I've simplified this, because of course, you calling over the top of a conversation can also disturb the contact under way. Saying that the frequency is in use makes it worse.

While all this is happening, the sun is moving, the ionosphere is moving, propagation is moving, the whole thing is like the Cat in the Hat balancing on a beach ball, complete with cake, rake and a fish still in its bowl.

The first thing you need to do when this happens is stop and take a breath. Nobody owns any frequency, so claiming that this is your frequency is not going to help anyone. If the other station is having a QSO and you're calling CQ, it's time for you to move, change frequency and QSY.

If you're Amanda or Marc, you can tell your contact that there is some interference and then call the other station that the frequency is in use. If they change frequency, all good, if they don't, tell your contact to change frequency.

There's no need for aggravation. There is no ownership. There's no point in getting upset and no mileage in making life hard for the other station. The fact of the matter is that there was what we call in networking, a collision. It's time to back off and renegotiate.

All this is exactly the same if you're using voice, Morse, FT8, or any other mode.

Take a breath, renegotiate, move on.

Now, if you're a QRP station like me, it's much more likely that you'll not be heard most of the time. In that case it's often much quicker to just to move without going through the negotiation process. Of course you can attempt to make a QRP contact with one of the other stations, but it's considered pretty rude to stick your head between two people who are having a cup of coffee together and ask them for their autograph, so don't do it on air either.

If you assume malice from the get-go, you'll find yourself unhappy most of the time. If you celebrate that all of a sudden there's propagation between VK6, VK4 and VK2 you'll end up much happier with your on-air experiences.

While I'm giving out advice, here's something I learnt during the week.

If you break a toe, tread carefully. Stubbing a broken toe hurts. Really. Badly. In case you're wondering, my new boot is not a fashion accessory.

I'm Onno VK6FLAB

The lessons we teach.

Jan 18, 2020 293


Foundations of Amateur Radio

When you become a member of the amateur radio community you become part of a small group of humans who know and understand certain aspects of life. That's not to say that others don't share this or that the knowledge is unique or special, but radio amateurs are required to know this before they receive their license.

In the past I've spoken about how getting a license is like receiving a key that opens the door to the world of radio communications. It's one of the more accessible ways to grab hold of this key and it's the recipe for life long learning.

During the week a friend of mine, a newly minted amateur, pointed out that this represents something that the general population isn't aware of or attaches little in the way of value to. The interconnectedness of radio spectrum is something that radio amateurs take for granted. To us it's obvious. A transmitter on 3585 kHz is fundamentally the same as one on 92.1 MHz. A key fob on 434 MHz is similar to a computer on 2.45 GHz as is a laser on 500 THz or an X-ray machine on 30 PHz.

As a radio amateur we're taught that the radio spectrum is a continuous phenomenon and that spectrum is shared among users with specific rules around interference and interaction.

Another thing we know as radio amateurs is the difference between the front and the back of a Yagi-antenna. We know about radiation patterns, about the ionosphere and how the sun and sun-spots interact with some of our activities.

The point is that our knowledge, it's fair to say, specialised knowledge, even at the lowest level of licensing, exceeds that of the general public.

This is all by way of background because this leads to something that I learnt during the week.

As amateurs we have a responsibility to be custodians of that knowledge, that is, to care for it and to ensure its accuracy and to preserve that knowledge.

For some amateurs that means that they want this information to be exclusive, but for me it means that this information should be shared and nurtured and encouraged in those people who make choices based on incorrect information.

For example, as a radio amateur it's my duty to inform a person who is contemplating breaking the radio spectrum licensing rules that they are doing so. Not because I'm a regulator, but because I have specialised information that they lack. Importing a radio module that's using a frequency that's not available in your country is an example of something that I am compelled to point out.

I know that some amateurs take this compulsion to the next level and become a de-facto police officer attempting to enforce those restrictions. I understand where that comes from, but I also know that this is not my role and it's not your role. If you feel strongly enough about a transgression, perceived or real, there are plenty of ways to deal with that. Reporting the offence to the regulator is one option for example.

Knowing which end is the front of a TV antenna means that you can point out a mistake to a home-owner about the direction their antenna is pointing at, but it doesn't mean that you need to climb on their roof to turn it around.

I've said many times before that having an amateur license is a privilege. It's a gift, even if you worked hard for it, it was given to you, bestowed on you by the regulator in your country.

It seems to me that having such a gift means that it should be treated as such. As radio amateurs we're not entitled to a license, nor are we entitled to transmit. We're granted permission to do so.

I think that it's important to keep that in the back of our minds when we set out to educate those around us.

As for the education itself. It pays to consider what you take for granted when you're giving advice. Telling a person about Wi-Fi propagation through a home is a complex topic. You can make the explanation as hard or as simple as you want, but don't expect that the person receiving the advice has the same background information or interest that you have.

I was once told by a statistician about how various statistics worked and what their background was. I was translating a program from Modula-2 into WingZ hyper-script. I didn't care about how it worked, just that the provided code did what it was supposed to and that what I wrote did the same thing. I had no interest in becoming a professor in statistics, despite the earnest instruction enforced on me by my employer 30 years ago.

It's been said that you must learn from the mistakes of others. You can't possibly live long enough to make them all yourself.

What and how we teach those around us can be the seed of something bigger. I may well have become a statistician if the information had been tailored to my requirements, but that chance was lost 30 years ago.

I think it's a great way to consider what we teach and how.

I'm Onno VK6FLAB

What's in a plan?

Jan 11, 2020 276


Foundations of Amateur Radio

As radio amateurs we learn which frequencies we're allowed to transmit on, where stuff lives and who has priority when there's a signal on the frequency you're operating on and when you need to contact your regulator if you hear an illegal station on the air.

Some of that information arrives in your brain by way of the education process that eventually becomes your license after a test. Depending on which country your license is valid, determines which region of the International Amateur Radio Union your activities fall.

Here in Australia, I'm part of the IARU Region 3, together with the rest of the Asia - Pacific region. In the Americas you're part of Region 2 and Europe, Africa, the Middle East and Northern Asia fall into Region 1. As amateur population sizes go, Region 2 and 3 each cover about 40% of all radio amateurs. Region 1 is about 20%.

Each of these IARU regions has a specific band-plan that is updated regularly as member countries adapt and negotiate different frequencies for different users. The band-edges might not change that often, but bands come and go, segments are added and removed as needs change. For example, here in Australia or VK, the 6m band has been changing because analogue TV has been changing.

Information about band-plans is not easy to come by. For example if I look at IARU Region 2, their documentation is pretty sparse. I've never managed to actually load their website and by the looks of it, neither has the Internet Archive. Given that Region 2 is all of the Americas and represents pretty much two fifths of all amateurs on planet Earth, that's a big hole.

There is some availability in Region 1 and 3, but those too leave to be desired. There does not appear to be any formal method of archiving or naming and the transient nature of the Internet all but guarantees that historic information like this is being lost at a high rate.

Even with those limitations in mind, there is plenty of information to be found. Let's look at Australia, for no other reason than that I was able to pull some of the historic information out of the bit-bucket.

You might be surprised to learn that there is much more change under the hood that far exceeds the band edges and segment changes. The Wireless Institute of Australia publishes the Australian Amateur Band Plan. Using the Internet Archive I was able to count that between November 2007 and November 2019 there were at least 25 different versions of that band plan published, for example in 2008 alone there were at least five different versions.

I managed to download 11 of those band plans which show the introduction of the 2200 meter band, the 630 meter band, changes to mode frequencies, DX frequencies, the allocation of emergency frequencies, changes to FM bandwidth from 6 kHz to 8 kHz on bands below 10m, the formalisation of WSPR frequencies, JT65, FT8 and JT9.

Now I must point out that the information I'm presenting here is incomplete. There are many more changes, just in VK alone. I'm relying on the Internet Archive which only sampled the WIA website 162 times between March 2008 and January 2020. Within those pages there were only 11 copies of the actual band plan and I've only compared three of them, August 2009, March 2015 and October 2019, and of those only a few changes that stood out.

And this is for Australia alone. This is on the HF bands. I've not even looked at the veritable feast of changes associated with the VHF and UHF bands, let alone the cm, mm and higher bands.

Even with this massive disclaimer, my point should be pretty clear. A band-plan is a living document. It changes regularly. Likely much more often than you realise.

I'll leave you with one burning question.

When was the last time you got yourself a copy of the band-plan? Seriously, when was it?

I'm Onno VK6FLAB

Where do you start?

Jan 4, 2020 240


Foundations of Amateur Radio

So, you've got yourself a license, or it's coming but you're waiting for the regulator to get the administration done and for your payment to go through. The excitement is building, you're itching to get started and you've told your family and friends what your new callsign is.

Then the day arrives. Your callsign is allocated, it's paid for and you're allowed to call yourself a licensed radio amateur, a member of the community, a part of history, the next thing in radio.

Now what?

Where do you start on this adventure of a thousand hobbies in one?

The truth is that you already did. Look behind you. You have a license, a callsign and you've found the community, well, at least some of it. How do I know that you found the community? Amateur Radio is a secret, known only to those who bounce into it. That bounce is where you found the community.

Like any community you'll find people you like and people you don't. People who share your interest and people who are doing things that make your head explode.

That said, is there any sage advice that I can share with you on your journey?

I do, but, you're not going to like it. In fact until you've been an amateur for a little while you're possibly even going to hate my advice. I know, hate is a strong word. If it's not all black and white for you, you're going to think I'm chickening out in giving you advice.

Wanna hear it?

Start somewhere, anywhere.

Let me say that again.

Start somewhere, anywhere.

One of the most fundamental aspects of this hobby is that it's driven by your personal exploration, your journey, your imagination and your adventure. It's entirely up to you to decide what you like and what you don't.

I know that there are those who think that advice should come in the form of buying a radio, erecting an antenna and getting on-air. For many that's a journey worth doing. For others that's the beginning of the end of the hobby for them. If you're unsure which of the thousands of activities you'd like to do, since you don't know what they are, I'll tell you a secret.

Neither do we.

Seriously. There are so many things to do in this hobby that not a day goes by that I find a new thing to do and look at. A new toy to play with, or a new adventure to embark on. This morning I realised that the antenna design and build I've been working on represents roughly 600 million different variations. If I did those manually, taking a generous 10 minutes per set-up, I'll be here for nearly 35 years, 8 hours a day, trying another set-up. Clearly my hobby now includes automating antenna modelling.

My point is that there are so many different aspects of life, the universe, and everything that intersect in some way with the hobby of amateur radio that there's bound to be several that you can think of right off the top of your head. You might immediately be dismissing them as foolish, but if we all did that, nothing would ever happen.

If you're looking for ideas, that's a whole different thing. Of course the nearest search engine is a possibility, but I do have to confess, it's a dogs breakfast. Another is to visit your local club and see what others are up to. You could watch YouTube videos or listen to podcasts or read articles. All these are options to get suggestions.

Ultimately, the whole point of this hobby is that you embark on your own adventure, start on your own journey, down your own yellow brick road. If you think what you're proposing intersects with amateur radio, you're right!

That's not to say that there's no benefit to be had from engaging with others, far from it, just that you are the chief architect of your destiny. You're in charge.

So get to it. Go do something, anything. While you're at it, document the adventure. One day you'll be glad you did.

I'm Onno VK6FLAB

What does Amateur Radio mean to you?

Dec 28, 2019 197


Foundations of Amateur Radio

Over the years I've been asked what the hobby of amateur radio is all about. My response has evolved over time, but it started with the lure of simple point-to-point communications. The antidote against such an example is that a mobile phone does that and more. Of course if you're already in the hobby you know that there is a massive difference between the two, but if you're an onlooker that is not nearly as obvious.

There are other problems with an answer like that. It doesn't cover the spirit of the hobby, the intent, the reach, or any of the other aspects of our pursuits that keep us all coming back for more.

I was asked recently to provide a credit to a fellow amateur for providing inspiration for an episode. Since then I've reflected long and hard about the nature of inspiration and what causes me to contribute and participate.

The reality is that my inspiration comes from all manner of nooks and crannies, from articles I read, videos I watch, discussions I have, activities I participate in, builds I make and emails I exchange. Not to mention friendships, random comments, shower thoughts and flights of fancy.

My understanding of our community of this hobby continues to evolve as I participate and contribute.

I think that underlying all of this is the expansion of my mind, my interests, my exposure to new things is what makes amateur radio such a massively interesting activity.

When I started I had no inkling that between learning how to solder and what a Fourier transform is lies this immense field of individual and community activity. What other hobby has the ability to link astronomy, moon, camping, community, planning, building, drilling, sound, language, antennas, internet, computing, valves, maths, propagation, mapping, transport, emergencies, physics, competition, camaraderie, satellite, soil, ionosphere, sun, batteries, old, new, invention and exploration?

In addition to the technical aspects there's the whole library of human interaction, teaching, learning, giving and receiving, socialising, friendship, discussion and debate to scratch the surface.

In amateur terms I'm still a babe in the woods and the more I learn the more I realise that this is likely to continue for the rest of my life.

For me, amateur radio is the binding force between interests. It's about wonder, curiosity and inspiration. It's about trying and failing, about testing and learning, about thinking and doing.

The magic for me is that you can do this at any level. As a 10-year old with a freshly minted license, or as a 90-year old with a twinkle in your eye. You can approach this as a scientist, or as an educator, as a submariner, or an accountant, as a truck-driver or a boiler maker, from young to old and anywhere at all, amateur radio is just plain interesting.

As for giving credit. I'd like to credit you for your contribution, for your participation and for your excitement.

Keep up the wonder and continue to make this community your own. In the end amateur radio means different things to different people.

What does amateur radio mean to you?

I'm Onno VK6FLAB

Lamenting the decline of the hobby.

Dec 21, 2019 270


Foundations of Amateur Radio

During the week I received an email from a fellow amateur who described that they were feeling deeply disturbed by the decline of the core knowledge underlying the education and certification of today's new amateurs. This is a topic I've covered previously and some of what I'm about to say will touch on things I've said before.

I come from a long background in information technology. My first introduction was around the Motorola 6502 processor in the early 1980's. At that time a computer with 5 kilobytes of memory was a big deal. I learnt to harness every byte and nurture every bit. I learnt machine-code, BASIC, Pascal and Modula-2, which went on to form the basis of my current profession.

The reason I raise this is because there are many parallels in the evolution of amateur radio and the evolution of information technology.

For many years I lamented the dumbing down of the skill-set associated with newly fledged computer graduates. In a nut-shell, hand-coded would always beat Java. I held that view for a long time, until it occurred to me that in the big picture it didn't matter.

Let me elaborate before you start jumping up and down.

In computing, every two or so years, everything doubles, speed, memory, bandwidth, etc. The price pretty-much stays the same.

This means that the inefficiencies introduced by "high-level" languages like Java result in very little in the way of performance loss, but in return the actual process of writing new software accelerates. This means that you end up with more functionality, quicker, at the cost of less efficient code. That's a pretty reasonable trade-off.

If that example doesn't speak to you, it's the difference between rolling out turf from the back of a truck to construct a new golf course and teeing off in days, compared to spending a week planting grass, from seed, nurturing it and waiting at least two months until you might consider playing a round.

Does a golfer care if was rolled turf or planted seed?

A similar thing is happening in our hobby. The advent of Software Defined Radio creates a new category of experimentation. The component count is reduced by several orders of magnitude, in return for functionality built by way of software and maths.

Of course that means that the new amateur of today has no idea in the operation of a valve and only limited understanding of a transistor, but in return they can create new modes such as WSPR, JT65, CODEC2 and the massive evolution of other digital experiments, and they can do that with tools unheard of 5 years ago, let alone 50 years ago.

I am an example of an amateur who knows of the existence of a valve and I have a rudimentary understanding of how it works. I am seriously considering building my own Software Defined Radio, from scratch.

I understand that this might not be something that comes easy and may even be seen as detrimental to the hobby, but I dare say that the introduction of the valve to a spark-gap operator caused the same experience, let alone the introduction of the transistor, the integrated circuit or the explosion of cheap single on chip systems that can be had for cents in the dollar.

The essentials still remain. For example, right now I'm working on an antenna. It involves sourcing nuts that seem to be made from unobtainium, even though they are completely standard in our community and have been for longer than I've been alive.

The self-learning of our hobby, the exploration, the investigation, the curiosity will endure. What we're going to be playing with tomorrow is not going to be anything like what we were doing yesterday, and I'm OK with that.

That our hobby is changing is unmistakable. That's true for every human endeavour ever. I don't agree that there is a decline, nor do I think we've lost more than we've gained. I think the future of our hobby, our community and our pursuits is strong and bright.

I'm Onno VK6FLAB

How did you get here?

Dec 14, 2019 367


Foundations of Amateur Radio

During the week I celebrated my ninth birthday. You might think that I'm quite eloquent for a nine year old and you'd be right if it was related to how I came to be born. My ninth birthday as an amateur appeared in my diary unexpectedly on a Monday and I took the liberty of telling a few people.

On one forum it started a wonderful series of comments from amateurs and would be amateurs about their experience coming to our community. I've shared mine before, so instead I'd like to share some of the stories that truly show just how diverse our amateur friends really are.

Floyd KK3Q says: My Dad was into CB radio (back when it wasn't so bad) and I was his antenna guy. He had black lung so I was the one who took down and put up his antennas for him. In the process I learned a lot (ask me later about a "smoke poles" and "buried 12V batteries") Well, Dad and I got into the illegal SSB frequencies and one night we visited one of the locals who happened to be using a Kenwood 520 on 11 meters. One look at that rig and I was in love. I never heard of ham radio and when I asked about it the owner said the radio was a "ham" radio and you needed a license to run one. Which she didn't have by the way. So I says, "Maybe I'll get myself a ham license and a rig like the Kenwood." She laughed at me, "You're just a stupid truck mechanic, you'll never get a ham license."

I never run from a challenge, skipped over Novice and got my Tech, wanted on 20 meters so under incentive licensing I had to upgrade to General which meant 13WPM CW and me partially deaf. Next I wanted SSTV but you had to be Advanced class so I upgraded. Finally I lusted after a short call sign so I upgraded to Extra back when 20WPM CW was still required. Been a nice run, learned a LOT from a lot of elmers.

Floyd has been a ham for 42 years.

Bill WK2KX has been a ham for 33 years. Will be 34 this January. Licensed at age 11. He goes on to say:

My dad and I did it together, but most of my family are licensed as well. My grandfather started it. His main claim to fame is that he served as general Eisenhower's radio man during ww2 for about a month. Now I have both my parents, a bunch of cousins, aunts, uncles, etc who are all licensed - enough that I've considered creating a "worked all (our last name)s" award, haha.

Tyrell KD7TKJ turned 18 as an amateur in September.

My stepdad wasn't a ham, but one of the kids he grew up with was... And my stepdad told me a story at a young age about how he and this neighborhood kid would go to the auto wreckers to pick up scraps to build radios out of, and then use said radios to talk to Australia... The details of said story really were never complete, and I've never met anyone since that claimed to have built a radio from car parts... But it was enough to get me to (get my mom to) get the ARRL Now You're Talking book and get licensed. I've been addicted to this more than any money making Enterprise ever since.

One amateur writes: I got my license 48 years ago. In high school, every day I'd pass a door with no window, just a sign "W2CXN". When I got the courage to knock, I was met with a person I knew liked his job. So happy to help. I remember thinking, how cool is that?

Peter KD2TCQ has been an amateur for 4 days and got interested because of packet radio as well as the ability to do on HF (which he needs to upgrade to do via phone but he's studying for that)

Ron K7UV says: I'm at 62 years and was licensed at age of 12. My dad and I built two receivers together and I wanted to do more than listen... the rest is history. Yup, I go way back before transistors and computers and remember cycles, mmF, aerials and condensers.

My original Hammarland receiver had around 13 tubes, the transmitter had 6 tubes plus the 2 meter converter had 4 tubes and my SCR522 had at least 7 tubes. It kept my bedroom quite warm in the winter and sweltering in the summer when there was no air conditioner, just fans.

The weird thing... I miss those days, maybe it's just my nostalgia kicking in. But radio and my interactions with my father were essentially what led me to radio.

Matt KD2MGM says: I suppose We're only 3. My brother and I put CB radios in our trucks in the summer of 16' but we quickly realized living out in the country that there weren't really any people on the air waves and that 4 watts wasn't enough to talk over the hills to each-other. These days we are not super active but still hop on the air once in a while.

You can find all these stories and many more on the amateurradio sub on Reddit.

For me, reminiscing over how you came to be part of this amazing community brings us all together. Our stories are not that different, we're all cut from the same cloth. Curiosity killed the cat, but it just makes amateur radio stronger.

How long have you been an amateur and what got you in the door?

I'm Onno VK6FLAB

The SDR earthquake will change our hobby forever

Dec 7, 2019 332


Foundations of Amateur Radio

In the early 1990's when I was a broadcaster I would come into the studio and prepare my show. That involved hours of preparation, but on the technology side it involved vinyl records, reel-to-reel tape on open spools, looped tape on cart, running edits and razorblades. If you're not familiar, a running edit is where you're playing the tape at normal speed and you hit record at just the right moment to replace the content. Of course that also requires that the thing you're recording is synchronised. Imagine yourself with four hands and three ears and you'll have a good idea. Razor blade edits required that you mark the tape where the audio started, chop the tape at that point and stick it to another piece of tape. The joy of having sticky tape, razorblades and audio tape strewn around the room and hoping that the tape didn't let go when you transferred the audio to a broadcast tape.

If you wanted to play a song at the right time, you had to start it by putting the needle on the record, spinning the platter until you heard the song, then stopping the platter, winding back half or three quarter turn from where the audio started, depending on the speed and torque of the turntable, and then when you hit play, you'd have about half a second until the music started.

At the beginning of the 1990's that was how it was done.

Then compact disc came in and we could cue up a song and hit the go button and get almost instant sound. You could change tracks at the turn of a dial. Vinyl records were phased out pretty quick.

In 1993 I switched radio station and instead of reel-to-reel we used DAT, or Digital Audio Tape. It had the advantage that there was no discernible loss of audio quality as you copied material, but there was no editing, since the bits on the tape needed to be aligned and you just couldn't do that with most of the available gear. The start-up delay was horrendous too, several seconds if I recall. A lifetime of dead air if you got it wrong.

You might be wondering why I'm going down memory lane like this?

The reason is that something changed, fundamentally, almost overnight.

In 1995 Microsoft launched Windows 95. It was in August and as the local computer show I organised a competition to give away a copy of Windows 95. I edited my competition stinger, a 15 second and a 30 second promotional audio segment, entirely on my computer. Using SoundEdit 16 on my Macintosh computer I could overly tracks, add voice-overs, move sound tracks around, add dozens of tracks, change the left and right channel independently, amplify or delete specific beats, all things that were completely impossible using the gear in a radio station at the time.

When I brought my stinger into the station managers office on my laptop computer, the earth shifted. Overnight everything changed. At that point radio stations around the globe started the race towards entirely being run from hard-disk. The digital revolution hit broadcast audio.

That's almost a quarter century ago, but that change cannot be overstated.

I think that in amateur radio we're looking at the same kind of change with the same level of impact.

Today you can go online and buy a NanoVNA for less than a hundred dollars. This device, a touch-screen driven tool, allows you to measure electrical circuits. For example, you might connect an antenna and measure the impedance of that antenna. If you connect a reference antenna to the second port, you can even measure radiation patterns.

Think about that for a moment.

You can measure a radiation pattern. That means that there is something that radiates.

Does that sound familiar?

Perhaps like a transmitter?

So this NanoVNA is essentially a transmitter and receiver in one box, currently runs up to 900 MHz, but the next version is already in the works and it's slated to manage 3.5 GHz, for the same amount of money.

So, a 3.5 GHz transceiver for less than a hundred bucks.

If you look at the internals of a NanoVNA, you'll notice that it's got much of the same bits as a software defined radio, because it is a software defined radio. Thanks to modern integration, at a component level it has significantly less complexity than the early 1980's microcomputers I grew up with like the Commodore Vic 20.

Yes, I know, it's not quite a radio. There's different filtering, different software, no audio input, or output for that matter, no Morse key, it doesn't do FT8 or some other fancy mode, but guess what, it's all software. The parts of this device aren't complicated, they're cheap, simple to program and I don't think it's going to take long before we see a new explosion of software defined transceivers that are begging to be used by radio amateurs around the globe.

We live in exciting times would be the understatement of the year.

I'm Onno VK6FLAB

Morse Code and You

Nov 30, 2019 286


Foundations of Amateur Radio

With the growing availability of new ways of communicating across the globe, from digital voice such as CODEC2, through weak signal modes like WSPR, JT65, MSK144 and FT4 to name a few, with Internet linked radio such as Brandmeister and DMR and the newly granted access to all Australian amateurs to all those modes, it's easy to overlook the one mode that started this adventure.

Morse Code.

It's no longer required to obtain your amateur license, so if that was putting you off from getting your license, you can breathe easy and get right to it.

Among all the shiny new modes Morse Code continues to hold its own and for good reason. It's simple, reliable, has an amazing signal to noise ratio and if you're driving in your car and you're stuck without a Morse Key, you can always just whistle into your radio.

If you've been following my journey through the hobby you'll know that I've been attempting to learn Morse Code. For a while now. It's been a challenge, more so since I spend less and less time in a car and more and more time behind my keyboard appeasing my clients. That's not to say that I've forgotten, just that what I've tried so far has eluded success.

A little while ago I received an email from a friend, Shaun VK6BEK who let me know that there was a discussion happening on a mailing list he was a member of and in that discussion I cracked a mention. Being the shy and retiring type I had to have a look for myself. To read the message I had to join, which is fine, since Charles NK8O has been bugging me to do that for years, well perhaps not bugging, perhaps keying me - hi hi. Turns out that the Straight Key Century Club, the SKCC, was having a recurring discussion about the topic of Head Copy or Head Reading.

To give you a sense of what that is, consider what I'm saying to you right now. It doesn't matter if you're reading this in an eBook on your Kindle, reading it on an email or online, listening to it on your local repeater, or via your favourite podcast player, for each of those the same process is happening.

You are not absorbing individual letters or sounds, but getting the meaning from the entire structure of a sentence. For uncommon words you might need to calibrate your brain, but for the most part you're just bobbing along understanding what I'm saying.

In essence you're doing the equivalent of Head Copy.

In Morse Code the same can be achieved. Ultimately it's a language, a tonal one, but a language none the less. Hearing the individual dits and dahs, followed by letters, words and sentences, eventually you'll get to a point where it all just flows.

I speak a few different languages, a curse or a blessing depending on your point of view. It means that I've become exposed to how language is built up. Initially when you hear a new language your brain is trying hard to figure out where the individual sounds belong, which sound belongs to which word, how a word begins and ends, how you make a plural, all the things you take for granted after you've learnt a language.

In Morse that is no different.

Within that context of discussing Head Copy, Gwen NG3P mentioned that she used the text edition of this podcast to convert into a Morse Code MP3 file so she could learn to hear Morse and bring them with her on her mobile phone.

Gwen and I had similar aims. In the past I'd done the same with a book, Huckleberry Finn if I recall, as well as random letters and also the ARRL Morse practice downloads, but nothing seemed to work for me.

For Gwen my podcast was an obvious source, so much so that I completely missed it, since they are short and on the topic of amateur radio. The language in use is likely going to be things that you'll hear on air and there's a smattering of callsigns, so all good.

Long story short, I spent last week converting all 454 episodes of the podcast to Morse Code for your Head Copy practice enjoyment. They're encoded at 25 WPM, or Words Per Minute and the tone is 600 Hz. I even put them online and made it possible for you to add them to your podcast player.

Best part?

I now get to hear Morse Code at a pace that I'm looking for, on a topic that's relevant and I have been receiving plenty of emails from others who are just as excited as I am.

You can find these episodes on the podcast homepage at http://vk6flab.com. Let me know how you go.

I'm Onno VK6FLAB

What's in a Whisper?

Nov 23, 2019 322


Foundations of Amateur Radio

A while ago I set up a WSPR, or Weak Signal Propagation Reporter at home. Before I go into the details, WSPR is an amateur radio protocol that allows stations to transmit their callsign, location and power level and for receivers around the globe to decode those and upload the results to a central database. It's a great way to see what you can hear and what propagation is like.

A couple of months ago the regulator changed the Australian License Conditions Determination, the rules of engagement around amateur radio and now all licensed amateurs in Australia can even set-up a transmitter although I haven't yet. Receiving is plenty of fun and anyone can do that.

Initially I used a piece of Windows software to track the contacts but to me it was like ordering a courier with an 18-wheeler to pick up a postage stamp. I looked around an found a piece of software that runs nicely on a single board Raspberry Pi computer. The software is called rtlsdr_wsprd, it's a mouthful, but it works nicely on a Pi with an RTL SDR dongle. The dongle I have is capable of using all HF frequencies up to 1766 MHz, so I can technically hear the 23 cm band, though I haven't actually heard any stations there.

I created a list of all the published WSPR frequencies and I listen to a frequency for fifteen minutes, pick another frequency at random and do it again, all day, every day. My log for this installation goes back about eight months and I get about a hundred contacts every month or so.

You might think that's a lot of contacts, but really it's not. The antenna is indoors, it's under a metal roof and while it's on the second floor, it's far from ideal, but it works surprisingly well.

What have I learned from this experience?

I've heard 36 different stations, across 11 countries and 23 grid squares, the furthest was G0CCL, a club station in Cambridge in the United Kingdom which was transmitting on 20m with 5 Watts. I heard it 14750 km away.

There are plenty of other things that I can extract from this. The most popular band is 20m, it accounts for nearly 70% of the contacts I heard. Surprisingly, I am also hearing contacts on 80m, as well as on every other amateur band that my receiver can hear. The 6m band is pretty popular too, nearly 13% of the stations I heard.

For my receiver, between 4am and 6am in the morning was the best time to hear something, together they account for just under 20% of the contacts. Locally the worst time is 8am in the morning.

From the data I've collected, April and May were the most active, accounting for nearly 70% of the contacts.

I must point out that the log is not continuous, there's gaps when the logging station wasn't switched on and when I was switching antennas and locations, so using the statistics I've given you here for your own station are probably not going to work quite the same.

The WSPR mode isn't perfect. It will happily decode rubbish and report on that, so I've manually filtered out the bogus information, like for example a grid square XI97LK, or callsign 3KE/21XWK, where neither the location or the prefix are real.

I can tell you that I was surprised that my station can hear 80m on the little telescopic rabbit-ear antenna supplied with my dongle. That same antenna is also fine at hearing 6m, so I'm pretty happy with that.

One thing that this little experiment reveals for me is that a cheap dongle is a perfectly fine way to start playing with a limited budget. It offers the opportunity to explore the RF spectrum using modern tools and techniques. Much of what I describe is absolutely possible with a traditional radio. Originally I had my station set-up like that. It consisted of my Yaesu FT-857d, a 12 V power supply, a CAT cable, an audio interface and a computer.

In stark contrast, my current set-up consists of two things. A Raspberry Pi with an RTL SDR dongle plugged in.

While this set-up cannot transmit, neither could I at the time. Since then there have been advances in both. There are all-band WSPR transmitters for a similar cost to a Pi and a dongle. Power it up, configure it and you're good to go. I'm eyeing off that as a future project, since it's perfect to use to see what bands are open for your station at any given moment.

If you've never had a go, you should. I've documented how my monitor station works and you can find it on the projects page on my website at vk6flab.com.

WSPR is a really nice way to get into many different aspects of our hobby and the barrier to entry is your imagination.

I'm Onno VK6FLAB

Putting a radio in a car.

Nov 16, 2019 247


Foundations of Amateur Radio

Putting a radio in a car.

As you might recall, most of my radio activity is done away from my shack. I tend to operate portable, camping, sitting on a jetty or using a picnic table while a BBQ is going nearby.

For me operating with my car as a mobile base made more sense than trying to cram an antenna in a home with little or no garden.

Putting a radio in a car can be as simple as bringing a hand-held and hanging it from the rear-view mirror, or it can involve a mobile phone mount that allows you to clamp it in place.

Pretty soon you'll want to have an antenna on the outside of the car, so then you start figuring out how to make it go through the car without needing to drill holes and sparking the ire of the other users of the car.

Not long after that you'll want to charge it, then the microphone will become inconvenient, changing frequency, using it for more than talking on the local repeater.

Eventually you might well get to the point that a hand-held is no longer appropriate.

Without telling you which radio to buy, since there are many different ones to choose from, with different specifications, different pricing, different functions and different sizes, there are plenty of roadblocks to radio bliss in the car.

The very first one is: Where to put the radio?

If your radio has a detachable front, that is, the buttons and display can be separated from the main body, you'll have more options, but if that's not possible, you'll likely need to find somewhere near and preferably visible to where you'll be using it.

There are transceivers that fit into a standard car radio opening which might come in handy if your car comes with all manner of bezels and curves. You might find a spot in the centre console, or overhead.

If you can put the transceiver in one spot and the head in another, then you can put the radio in any little hidey hole, for example, under the passenger seat, or in the luggage compartment, in the glove box, or behind the drivers seat.

When you are looking for a spot, consider how you're going to get electricity to it and how you're going to connect the antenna. You'll likely need to connect the power supply wire directly to the battery, which might determine how the power gets into the cabin of the car.

If you can drill holes in your car, you'll have extra options, but consider that you'll need to protect the wire that goes through those holes and you'll also need to protect the steel, given that once you drilled that hole, it's no longer protected by paint from rusting.

The same is true for the antenna. Can you use an existing path, or do you need to make a new one? If you put the radio in the luggage compartment, can the antenna lead exit that and what happens if it rains?

In my set up I have an all band radio, it does HF, VHF and UHF, but I didn't want to have multiple antennas on the car. The radio has multiple sockets, so I used a coax switch that's connected to an antenna mount on the rear of the car and ran two lines back to the radio, so I can switch between HF and VHF. Of course I need to swap out the antenna, but I'm not switching whilst I'm driving, so that's no problem.

Other things to consider are what noise comes from the car. I don't mean the zoom-zoom noise, I mean the noise from things like the alternator. How will you deal with that? What about grounding? How will you make the ground plane of the antenna? Can you use braid to connect the various panels of the vehicle to each other?

If your mount is temporary, like for example a magnetic mount, how will you protect the paint work? Can you clamp something across an edge, or will you need to drill a hole?

If you're at all unsure, then try some set-ups. Run a temporary power supply through a door, figure out where stuff goes. Look at what your friends have done, test it by going out, park somewhere and try to use it for real.

It can be daunting to set-up a car, but it is very rewarding and it's a great way to get used to the many aspects that are involved once you dive into this hobby.

I'm Onno VK6FLAB

Where is North?

Nov 9, 2019 280


Foundations of Amateur Radio

The other day we were aligning an antenna for a contest. It had slipped on the rotator pole during a recent storm and when the rotator was set to zero it was pointing somewhere south east. Not ideal if you want to point your antenna at a particular station.

The topic of the direction of north came up. There was vague hand-pointing, some mobile phone compass magic performed and north was arrived at. I asked if that compass took into account magnetic declination which in turn was met with blank stares.

So, what is magnetic declination and where is north?

It's likely that in school your first physics lesson was around magnetism. Playing with magnets is an easy way to start the conversation around science. One thing you learn in school is that opposite magnets attract. A north pole to a south pole and so on. A compass is a simple magnet with a north and a south pole. So, the north pole of the compass is attracted to the south magnetic pole of the Earth.

This means that the Earth's north magnetic pole is currently at the bottom of the Earth. Also, while we're on the subject, the magnetic field lines that leave a magnet are defined as being the north pole of that magnet. So on top of the planet the magnetic field lines enter the Earth and at the bottom of the planet they leave the Earth.

That definition of north and south was the first to be used and it was pretty successful in getting sailing ships all around the globe. Since then the definition has changed into defining the poles as the points around which the Earth rotates on its axis. The north pole is the one on your left as you face the rising Sun.

So, the north pole that you and I talk about in day-to-day conversation refers to an imaginary point where the Earth rotates around you and you stay still - ignoring for a moment that the Earth is hurtling around the Sun and the Sun is moving around in the Solar System and the Solar System is moving in the Milky Way Galaxy and its moving inside the Universe, turtles all the way down.

In case you're wondering how fast you're moving while you're standing still, it's in the order of 360 km per second in relation to the cosmic background radiation. By the time you've finished this you'll have moved about a hundred thousand kilometres from where you started.

The subtle difference between the definition of north being related to the magnetic pole and the rotation axis means that there's a difference where your compass points and where north is. You probably already knew this.

You might not know that the amount of distance between both the magnetic poles and the rotation poles changes over time. The magnetic poles of the Earth are constantly moving. That's pretty straight forward, but there's more. The Earth's magnetic field isn't pretty. It's not all straight lines and unicorns. It's messy, very messy. And the mess is moving. Normally there's a new map published every five years, but sometimes that's not enough to account for the movement. For example, early in 2019 a new map was published out of sequence to account for changes that were larger than expected.

Why the map you ask? Because field lines are not straight. You'll find all manner of weird shapes and swirls. This means that where ever you are on Earth, your compass is pointing in a different direction, because it's not pointing at the magnetic pole, it's aligned with the magnetic field line which could be as much as 20 degrees off, in either direction, so 40 degrees error could make you completely miss Australia as you're sailing around the planet.

If this is beginning to sound a little familiar, you might consider our Sun. Every sunspot is a magnetic pole. They come in pairs, a magnetic north pole where the magnetic field leaves the Sun and a magnetic south pole where it enters the Sun. If you've come across the impact of the Sun on radio communications and the ionosphere, you'll already know that the Sun is a turbulent place. Sunspots come and go, they move around, there's cycles within cycles, solar minima, maxima, pole reversals, lots of stuff that makes this a variable feast.

The Earth is doing this too. Not as fast, not as hard, not as big as the Sun, but measurable and a rich source of research for Geophysicists and Geologists, since we can even figure out that the magnetic field on Earth reverses itself, has done many times, just like the Sun.

So, next time you get the question, where's north, check out the magnetic declination map for your location, you might be surprised where your compass is pointing, it's almost certainly not north.

I'm Onno VK6FLAB

In pursuit of a challenge

Nov 2, 2019 228


Foundations of Amateur Radio

An interesting question came up the other day. It's there such a thing as a solo contest? At the time I answered with examples like talking to a hundred countries to achieve the DXCC, or doing that on every band. I gave other examples too, but today I'd like to come at this from a different angle.

When you go fly fishing, you typically stand in cold water trying to tempt a fish into taking your lure. If you are in the right spot at the right time with the right bait you might be lucky and achieve momentary bliss with the capture of a fish.

That moment, the peak of achievement when the fish bites, that's a moment for you and you alone. Of course you'll be able to brag about it later and bask in the glory of your achievement, but the moment itself is a solitary experience.

Many aspects of amateur radio are exactly like that.

The circumstances are not even that different. Instead of standing in cold water, you're having your eardrums assaulted by noise. Instead of a line you have an antenna. Instead of a lure, you have your voice, but the same thrill happens when you hear your callsign being said by the other station. Calling back and forth with the exchange is much like fighting a fish. The bragging is no different.

Of course amateur radio isn't actually fly fishing, but it's close.

One of the things that you can do with amateur radio is achieve the bliss of success together with friends. You can compete in a contest together and share the missed opportunities, the misheard callsigns and what ever else chance throws in your way. Yes, I know, in fly fishing you can participate in the World Championships as a team, but generally it's a solitary experience.

Oh, I should point out that my relationship with a fishing rod is an unhealed one. At the age of ten or so I managed to catch a fish in the local canal. At age 36 I caught a tiny fish on a safety pin in a pool at the base of a waterfall in the Kimberley. Typically I carry a fishing rod around into the bush with a lead weight to hoik it through a tree so I can pull a wire antenna up, so if there's any inaccuracies in relation to my dissertation on fly fishing, please don't hesitate to let me know.

I've said this before. Amateur radio is lots of different things. It's a pursuit of technology, of excellence, of challenge, fun, victory and it's about having the experience.

You can do this on your own and feel the amazing joy of making a contact, or you can do it with friends. Ultimately the choice is yours.

Which ever one you pick, how you play is up to you. You can decide to see what comes along, or you can set out to make something happen. There is no right or wrong way, nobody to tell you that you must this or should that, it's entirely your decision to make.

I like, actually, I love trying to get better at whatever I do. Talking to people, crossing the street, building an antenna, making a contact, winning a contest. I love trying new things, having new experiences, and seeing what others do differently. That's my make-up, it's me.

If you want ideas on what to do, feel free to ask, but expect me to be interested in how you go. If you tried something new, share your experiences and tell your tale. I really don't mind if it failed. I'd much rather hear that you tried, rather than gave up before you started.

So, what's your next adventure?

Perhaps you have a waterproof radio and you want to bring it when you next go fishing ...

I'm Onno VK6FLAB

First Solo

Oct 26, 2019 213


Foundations of Amateur Radio

The other day I looked in my diary and noticed that it was the anniversary of my first solo flight. If that's not familiar to you, it means I got in an aeroplane on my own for the first time, taxied to the end of the runway, made a radio call to warn all the other pilots, took off, flew a circuit and landed safely. All the essentials for flying a plane.

It occurred to me that there was a period of preparation associated with that flight. I did training, I practised, I got my gear in order and then after all was ready, I did the actual flight.

In a technical hobby like Amateur Radio it's easy to get stuck in any of the steps leading up to your first transmission. It's just as easy to get stuck getting ready to do a contest, activate a digital mode, climbing a SOTA peak. Each of those activities are part of our hobby and doing those can provide you with a sense of achievement, a measure of success and ultimately the confidence to continue in this hobby.

I've said before that there is a contest on pretty much every weekend, if not quite every day. People who participate in those contests do so for a variety of reasons, from testing equipment, to getting different countries in the log, to catching up with friends, to winning.

I'm a die-hard contester. I love the chase, love to improve on my performance, get better, do more, faster, etc. That's not to say that there are times when I use the opportunity of a contest to try something new.

At the moment I'm in the process of trying to figure out how I can record my voice into appropriate audio files so I can make the logging tool N1MM make all the noise on behalf of my vocal chords. Calling CQ for hours on end is not a good way to protect your voice and for those within earshot it's no way to spend a weekend listening to gibberish fill the house.

I don't know how I'll go. Admittedly I've left it a bit late for the contest at hand, but I'm going to give it a go. I doubt I'll achieve more than a dozen contacts, if any, but then that's not why I'm doing it.

My point is that you can, for any reason at all, participate in a contest. You don't need permission, you don't need to be asked, you can just decide to. When you're ready, when you feel the urge, when you think you can, or even if you think you can't, have a go. Today. Now.

Some fair warning. If you pick a busy contest, like say the CQWW, you'll find that there are plenty of other stations around. They too are having a go at what ever level they choose to. Some will be out to win and others will try to say hello and want a chat.

When you start you might feel the need to do lots of calling. Better use of your time is to have a listen and see what's happening. Check out the other operating techniques. Once you have the hang of it, try it yourself. It won't hurt, nobody will bite, though some might get testy if you jump on top of a rare station.

If that's all too much to try and it's a little too scary, find yourself a local net, a discussion, an on-air meet-up, and have a listen. Then, if the going's good, join in. Key your microphone and say your callsign. Take it from there.

Going Solo is something that every amateur you hear on air has done. It's time for you to do the same.

Now get on air and make some noise!

I'm Onno VK6FLAB

World Wide Radio Operators Foundation

Oct 19, 2019 261


Foundations of Amateur Radio

The other day I accidentally learnt something new. I know, it's crazy, sometimes I surprise myself.

I received an email that announced an activity from something called WWROF, more specifically, the World Wide Radio Operators Foundation. It caught my eye, because it was announcing a webinar about an upcoming contest, as it happens the largest annual amateur contest, the CQ World Wide. The time zone for the webinar put it firmly during my sleeping hours, so I asked about the availability of a YouTube video after the fact.

Got an email back from Founding Director, Mark N5OT, and you'll be pleased to learn that there is in fact a video, not only that, videos going back to the dawn of the organisation with topics focused on Amateur Radio Operating.

There's information about Receiving Antenna Metrics; Constructing a Horizontal Waller Flag; Ethics in Contesting; RTTY or Legacy Digital Contesting; Solar Spot Cycles; Dayton Hamvention; High Performance Receive Antennas for a Small Lot; World Radiosport Team Championships; Contest University; Operating two bands, using synchronised, interleaved QSO's; Remote Multi-Multi Contesting; and more, much more.

To think that I didn't know this group existed and I've been here for a while, turns out, they've been around since 2009 when the foundation was created by a group of radio amateurs who saw a need for an independent organisation devoted to the skill and art of radio operating.

Their motto is:

"Dedicated to improving the skills of amateur radio operators around the world, utilising education, competition, advancement of technology and scientific research, promoting international friendship and goodwill, and preparing them to better serve society in times of communication need."

Gotta say, if it weren't for the fact that it's on a web-page that I don't control, that could have been written by me.

The WWROF puts contesting front-and-centre in the art of operating. They believe, and I agree, that amateur radio contests provide a means of testing operating skill.

So, what have this group of radio operators been up to?

Well, they administer the Cabrillo log format, support Contest University, support webinars on topics of interest to Contesters, created the Contester's Code of Ethics, Sponsor the World Wide Digi DX contest, are developing wideband recording systems, manage contest awards and donate equipment to young contesters and developing-country contesters, and finally they support the World Radiosport Team Championship.

So, if this leaves you thinking that I'm advocating that you should check out this group, at wwrof.org, you'd be right.

If you're looking for something to learn and YouTube is your medium, then check out the WWROF channel. Lots to see and do.

One thing that might not be obvious from my glowing reports is that this is for you at whatever level of contesting you find yourself, not only that, it's not about contesting per-se, it's about operating as a radio amateur.

For example, you'll find a discussion by Craig K9CT who describes how to plan your station, from finding land, selecting antennas to the layout of your shack. There's information about how to contest as a Rover Station by Rick K1DS. There's outlines of rules for various contests. Carl K9LA describes how to use Grey Line Propagation on the Low Bands, and Ed N4II talks about how to use 80m to get from Florida to the Cocos Keeling Islands around the corner from me, well 2932 km and that's 300 km closer to me than Sydney.

I should mention that I have no relationship with the World Wide Radio Operators Foundation, but given their purpose of existence, I endorse their efforts. Their address is wwrof.org.

I'm Onno VK6FLAB

How to make contesting interesting to an audience?

Oct 12, 2019 282


Foundations of Amateur Radio

As you might know I enjoy doing contests, actually that's an understatement; I LOVE doing contests. I think that they represent an excellent way to learn about operating procedure, propagation, band selection, antenna direction, callsign recognition and dealing with adverse operating environments. In short, I think that contesting teaches you lots about amateur radio in a very short time.

That said, doing a contest, or learning from a contest is challenging and for a new amateur it can be absolutely daunting.

If you have the luxury of a club station, you're familiar with the following picture.

Bunch of people sitting around in the shack, one person operating the radio. If the operator has their headset on, the conversation in the shack will be about life the universe and everything. If the operator isn't wearing a headset, the conversation in the shack will also be about life the universe and everything with the radio blaring in the background and the operator initially asking people to keep quiet so they could discern that elusive DX station, frustration growing with every contact.

Being at your own station might not be much different. Replace shack with home and the people in the shack with your family and you get the picture.

If you step into that environment as a new amateur you'll get a sense of camaraderie, but little in the way of contesting knowledge. If you're lucky you might have someone point out what's happening, but quickly the conversation is likely to turn to other topics. It's hard to participate when you can only hear half the conversation.

Recently I did another contest. As I said, I love them, so why not? I invited two new amateurs to the party. They arrived separately at different times and had vastly different experiences. My first guest got to see the back of my head whilst I called "CQ Contest VK6FLAB", followed by "NK8O, you are 59020", then "104, CQ Contest VK6FLAB".

My second guest got to hear the whole contact.

"CQ Contest VK6FLAB", "NK8O" "NK8O, you are 59020", "VK6FLAB you are 59104" "104, CQ Contest VK6FLAB".

In both cases I was wearing a headset, but in the case of my second guest I'd finally achieved something that I'd been aching to achieve for years. I managed to combine the best of both worlds. The radio audible in the shack and the operator wearing a headset, at the same time.

My intent has always been to get this to work, but radio after radio, configuration after configuration, shack after shack, this seemed to be a doomed attempt at getting my fellow amateurs to understand why this was important and how we might implement this. One of the radios in the past had a Headphones plus Speaker option, but it wasn't ideal and as I recall, it handled sub-receivers poorly, not to mention the menu shenanigans required to actually make it work. The current radio in the club-shack is typical of radios today. Headphones or Speakers, not both. This radio has an Ethernet port, so there was talk of using Voice over IP and extracting it to multiple destinations. This conversation went on for a while.

I then hit on the idea of using computer speakers, tweaking them by clipping the wire that mutes the speaker when you insert headphones.

In the end, the solution was much nicer, much simpler and easy to implement for any radio with a headphone socket. I confess that I cannot believe it was this simple, but it was.

Get yourself a Y-adaptor. It's basically a headphone splitter. You can get them almost anywhere, supermarket, petrol station, electronics store, anywhere that sells mobile phone accessories to teenagers who want to share their music with their friends.

Plug the Y-adaptor plug into the radio headphone socket. Plug your headphone into one of the Y-adaptor sockets and plug some powered computer speakers into the other Y-adaptor socket. Set the volume on the radio for your headset as needed and adjust the computer speaker volume as required.

End result is an operator who can hear the contact and a shack that can teach a new amateur about what's going on.


Feedback from guest number two - this changed everything and he learnt a great deal after that.

Mission accomplished.

I'm Onno VK6FLAB

Leave some bread crumbs behind

Oct 5, 2019 313


Foundations of Amateur Radio

About a year or so ago I received a message from a friend of mine. The message asked if I would have or could find a use for some amateur radio gear from their active amateur father who became a silent key. That started a sequence of events that leads us here, today. In the year that followed that message I became the grateful owner and archivist of an amateur shack that belonged to Walter VK6BCP (SK). Walter had two calls that I know of, VK6BCP, last logged on the DX cluster on the 5th of April 2012. His other call, from Switzerland, was HB9CAI, last reported on the cluster on the 23rd of February 2005.

The more I dig into Walter's collection of all things that make a shack, coax, connectors, boxes with spares, power supplies, odds-and-ends, the more I find a kindred spirit. I never met Walter, but he and I share the same sense of order. We sort things in the same way, we have the same kinds of things on hand and it's gotten to the point where it's hard to tell where his shack ends and mine begins.

Walter's shack contributed several radios, some of which I loan out to beginning local amateurs, I took one with me on a recent trip and I've been using one to run a weekly net to see how this particular radio works and what quirks exist.

One of the requirements to actually switching on that last radio brings me to bread crumbs.

I needed a power supply to make the valves glow - well, the digital display - but you get the idea. There was a suitable power supply on the shelf, but I had no idea when it was last switched on, if it worked, if it would set fire to my shack, what the state of it was. It looked near new, no scratches on the paint, bit dusty, but it looked as well loved as my own power supply, which is now coming up to nearly a decade old.

I picked it up and the power supply rattled. Never a good thing in a device that has no moving parts. On closer inspection I noticed that only four of the fourteen screws were holding the case together and it stopped me from plugging the thing in and turning it on - with a stand-by fire extinguisher at the ready - mind you, I might have been slightly exaggerating with the fire extinguisher.

I did what any enterprising radio amateur would do in that situation, I got out a screwdriver and extracted the four remaining screws and lifted the lid. I wasn't sure what I would find, but nothing prepared me for what was there, though Walter being Swiss should have.

Inside this lovingly maintained power supply I found a little zip-loc bag with ten screws. The ones missing from the case. This was the source of the rattle.

I also found a disconnected fan lead, actually, it had been purposefully cut and folded back.

Now why do you suppose that was?

For my money, Walter knew this power supply well. His power requirements didn't need a fan - truth be told, mine probably don't either - and to keep everything in one place and to remind himself that he'd made a modification, he'd done the smart thing, make it obvious that something had been modified.

He could have put a sticker on the case, but over time that would have faded. He could have carved his initials into the case and carved an instruction, but both of those would have reduced the aesthetics of the power supply and if his callsign ever changed, or if he reconnected the fan, he'd have to start again.

What I found was something that gave me pause to consider how you manage to document what you've done, not only for yourself, but for others who might stumble on your modification. I'm certain that Walter never considered that one day I'd be telling you this story and thanking him for his preparation, but that's exactly where we are.

You might come away from this wondering what the point was of all this?

The point is, you can prepare your shack for events that might not happen. You might lose your memory, become a silent key, or have a beginner borrow your kit. You'll never know what it will be. What you can do is make it possible to discover that something has been changed. Walter could have just as easily put all fourteen screws back in and I would have never been any the wiser. I might have thought that the fan only came on under load, instead of not coming on at all, ever, because the lead had been cut. My first sign of trouble would have been magic smoke escaping and perhaps the need for a fire-extinguisher.

Leaving bread crumbs for discovery is a really simple and helpful way to document your adventures.

Thank you Walter VK6BCP (SK) - it's been a pleasure to know you through your shack.

I'm Onno VK6FLAB

Lessons Learnt

Sep 28, 2019 241


Foundations of Amateur Radio

Lessons Learnt

Learning to me is an ongoing process. For some reason that's not a universal experience. I've met people who cram for an exam, pass their test, get the certificate and hang out their shingle. The retained knowledge is spotty and vigorously defended as the final word on the topic.

It's never been like that for me. I tend to walk through life intensely curious about the how and why of a thing.

Take my recent adventures operating a new to me radio with a new to me antenna in a new to me location. It went sideways, fast, with little direct evidence of the experience to show for itself.

I did learn several things.

I expected that having switched on the radio at home, transmitting into a dummy load and receiving was enough to prove that the radio was operating normally.

The fact that I didn't hear anything and didn't know if that was because of my set-up or the radio itself was not helpful.

I expected that bringing a long-wire with a multi-tap un-un would guarantee that I'd be able to operate on any band.

The fact that I got a high SWR everywhere didn't tell me what the cause was and not having access to my testing equipment made troubleshooting much harder.

I expected to plug the radio into the car and brought battery terminal clip adaptors and a cigarette lighter plug adaptor to facilitate this.

I didn't expect to operate separate from the car, hadn't considered that the voltage might drop below acceptable and didn't know how fast that might happen. I sort of expected that the radio would have a voltage display, but so far that's eluded me. I even have an in-line Volt meter back at the shack, would have been more useful than the torrid I packed.

I expected that the length of the power leads would be sufficient to comfortably install the radio into the car and operate without having to be mindful of where to put my feet.

I didn't expect that the power lead was only just long enough to place the radio in the passenger side foot well and didn't offer any flexibility at all.

I expected that I had taken with me enough in the way of connectors and adaptors to connect various antenna options together.

I did. I managed to bring one surplus item which couldn't be connected and didn't need to be either.

I expected that my coax patch lead was sufficient to have the radio inside the car and the antenna outside the car.

It was. Just.

I expected for planning purposes that Google Maps would work the same as it does at home. Satellite and street views pretty much in sync and roads shown on the map actually existed.

It didn't. The satellite view was current, street view was 11 years old for some streets, pre-building boom, pre-cyclone, pre-historic pretty much. There were roads indicated that didn't exist, couldn't exist, had never existed and would never exist. The place I stayed at has been there for more than a decade, but Google Maps shows me surrounded by water. The local board walk has been there for over 30 years, but Google doesn't know it exists.

I expected to be able to get anything missing from my kit with little trouble from local big box stores.

In reality, the local electronics dealer is an authorised stockist of a well known brand, capable of ordering in most stuff, but a full brand store with actual stock was well over 100km away.

I expected that buying a battery locally might cause weight issues for packing luggage.

In reality, shipping batteries across the country is non-trivial and in many ways should be budgeted as a disposable item, since shipping is likely to be either not permitted, or cost as much or more than the original purchase price. It boggles the mind how these batteries actually arrive at the shop where you buy them, but no doubt that's above my pay grade.

I'm sure there's more to learn from my adventures, but I'm happy to have experienced this to add to my skill set as a radio amateur.

What learning have you been exposed to when you least expected to be?

I'm Onno VK6FLAB

Going on an outing

Sep 21, 2019 183


Foundations of Amateur Radio

Going on an outing

After my fun and games working out how to manage power for a temporary radio set-up, away from my shack and normal infrastructure, I had the pleasure of actually going out to get on air and make some noise.

A national contest was on offer and it's always been a favourite of mine. It's simple to log, you can work as much or as little as you like and there's generally a good community spirit associated with it.

After mapping my way around the neighbourhood, I'd found a few candidate locations, nearby water, trees, parking, bit of separation from housing, all the good stuff you need when you go walkabout.

Had the opportunity to configure the car, setting up in an underground garage, nice and cool, good light, perfect start to a contesting day. Found a suitable route for the power lead from the battery to the radio, set-up the various bits, microphone, dummy load, untangled the wire antenna, all ready to go.

Got in the car an hour before the contest started and drove 5 minutes up the road to contesting location candidate number 1. Shame about the overhead power lines. On to location 2, shame about all the cars, location 3, overhead power lines, location 4, no parking signs, location 5 through 7 couldn't be found because the map and reality didn't quite agree with each other.

At that point I made the decision to go and have some lunch. Best thing I could have done. There was another location, number 8 or 28, who cares at this point, but it was 50km away, just under an hour drive. My trusty navigator and aspirant logger and I decided to bite the bullet and head on out into the great unknown.

We arrived an hour after the start of the contest. Drove up and down the shore of a local man-made lake and after dismissing several full sun locations, found a little dead end track with nice trees and plenty of shade. It's a 26°C day, so sitting in the full sun is not a pleasant thing in a dark car.

Used my rope and gifted weight - thanks Alan VK6PWD - to find a spot for the antenna wire, set-up and powered up. Tested the SWR. High, everywhere. Tested with different un-un settings, 16:1, 9:1, 4:1, high, everywhere. Found a loose connector, one I'd tested before packing and then another. Replaced them both, still high. Dummy load was fine.

Tried three different antenna layouts and decided to see if I could actually hear anything. Listened to all NCDXF beacons on all bands. Nothing. Not a sausage. At least the cattle coming past for a look-see were having a great time.

After all that, the only thing left to do was to pack up and drive home. Mind you, we did find a nice red wine on the way home, so it wasn't a complete loss.

In past years I might have been quite upset about this experience, but with experience comes acceptance that sometimes it's just not your day.

I'm furiously scribbling down all the things I've learnt from this outing. I'll leave that for another time.

I'm Onno VK6FLAB

Planning for an outing

Sep 14, 2019 199


Foundations of Amateur Radio

Planning for an outing

Recently I had the opportunity to use a new radio whilst I was far away from my shack. It wasn't unexpected, I took the radio with me, planned for the experience and packed light with intent.

My original packing included a 10m length of coax, my analyser, some antenna weights, wire, rope, power leads, BNC adaptors, barrel connectors and a balun. Total weight came in at about 7kg. More than double the weight of the radio itself. The biggest weight came with the coax, so that stayed home. Got rid of all the "what-if" adaptors, dumped the antenna weights, dumped the balun and the analyser, added an un-un, and a multimeter and came in at just under 5kg.

The idea was to operate from the car, chuck a long-wire into a tree and make noise.

Then I got to where I was going and learnt that there were lots of SOTA peaks nearby. If you're not familiar with SOTA, it stands for Summits On The Air and it's a way of encouraging people to go out and make noise while also encouraging others to listen out for your activation of a nearby peak. As an aside, it's separate but closely related to WWFF, World Wide Flora and Fauna, since peaks are often in National Parks and who wouldn't want an excuse to activate two things in one sitting?

One of the most basic rules of SOTA is that all equipment must be operated from a portable power source (batteries, solar cells, etc). Operation is expressly forbidden using permanently installed power sources or fossil-fuel generators of any kind.

That of course means that using the battery in a car is not allowed, though I suppose I could unbolt the battery from the engine bay, but I'm pretty sure that the hire-car company would frown on that plan.

I set about attempting to find out how much power the radio actually draws at 5 Watt, and how much battery I'd need to activate a peak.

Given that my shack wasn't where I was, I couldn't just plug it into my fancy power supply and read the power draw from the display, should have done that before I left. Shoulda, Coulda, Woulda. I resorted to asking the community, but that was dependent on the kindness of strangers.

Another hitch was the battery. I came up with the brilliant plan to use one of those high-capacity jump start boxes, 18Ah or so. Picked the one I liked the best, figured out if I could ship it back to my shack on return, since it likely couldn't fly, both from a weight and a dangerous goods perspective and found a supplier locally - well 108km away - and then, me being me, I downloaded the user manual, and learnt that what I wanted to do, power my radio, was expressly, strongly, not recommended, fear of explosion and the like.

Planning foiled.

I still wanted to operate, contest to be attempted, SOTA be damned. How could I operate and not fear that I'd be draining the car battery?

A cigarette lighter mounted Volt meter!

So, now I can connect the radio directly to the battery in the car and check the voltage whilst I'm operating.

Now all I need is a parking spot with a nearby tree or gazebo and no noisy neighbours or overhead power lines.

I'll let you know how I go.

I'm Onno VK6FLAB

Boating adventures

Sep 7, 2019 217


Foundations of Amateur Radio

Boating adventures

The other day I was on a boat. That's right, me, on a floating thing, on the water, the ocean actually, steering and everything. I should confess that when I was younger I spent most weekends sailing as a sea scout in Holland.

Managed to become a bootsen, that's the bunny in charge of a boat. Sea scouts, zee verkenners, was also my very first introduction to amateur radio through JOTA, Jamboree On The Air, where scouts across the globe come together, though it didn't make quite as much impression as breaking the middle finger on my right hand an hour later, but that's a story for another day.

So, me, on a motorboat, a tiny one, but still.

You may be wondering where this is going, trust me, it's relevant.

In preparation for my boating adventure I pulled out my trusty hand held radio, a waterproof Yaesu VX-7R. If you're not familiar with it, it's a tiny radio, capable of tuning between 500 kHz and 1 GHz, not quite DC to Daylight, but impressive nonetheless. I have it programmed for all registered Australian repeaters. One state per group in case you're planning to program yours.

One of the in-built options is to select Marine Channels. They're numbered from 0 to 281. I've looked in the past and in Australia the channel numbers don't follow any logic as simple as that. Numbering is all over the place, 84 channels as far as I can tell, I had to count them, the highest channel number is 2086 and there's channels with names like AIS 1 and AIS 2 rather than numbers.

If you're a yachtie, you're laughing your head off right now, but I'm making a point about Amateur Radio. We don't do channels here, well mostly we don't, unless we picked up an ancient radio cheap from somewhere and re-purposed it for Amateur Radio, but to coin another sailing term, by and large, we do frequencies.

So, here's the thing. My radio is perfectly able to transmit on marine frequencies and being a responsible person I thought it would be smart to bring my radio, just in case. I will confess that I didn't. After discovering that the marine documentation was all about channels, and decoding frequencies was beyond a quick look-up, I thought that it would be prudent to leave my radio at home. I had a mobile phone with me, was staying near to the marina and the boat owner actually supplied a radio.

So here I am, a semi-experienced radio amateur, completely clueless about marine radio. While I was figuring out how to tell you about this, I managed to find the government website which referred to a training website which referred to a user guide that actually had a list of channels and frequencies side-by-side. You'll be pleased to learn that channel 16 on my radio, the emergency marine channel is on the same frequency as the official channel 16 in Australia.

My point is this. We have a common interest in communicating. In the case of an emergency it would be useful to know what marine channels relate to what frequencies and how we as radio amateurs can help if required. It also means that we as radio amateurs are not the all knowing beings we believe ourselves to be. Of course we already knew that, so we keep learning.

I know I'm going to learn how marine radio channels work. I'll probably have a look-see at other channel spectrum users and see how they relate, so I can know how their system works in case I ever need to.

I'm Onno VK6FLAB

Gate-keeping, special people and bullies.

Aug 31, 2019 306


Foundations of Amateur Radio

Gate-keeping, special people and bullies.

One of the recurring topics in my experience of amateur radio is that associated with people who use the hobby as an excuse to sow discontent. That comes in many forms, at the extreme end it's harassment, but it also comes in the form of gatekeepers and nay-sayers.

It's important to realise that while this behaviour is not limited to amateur radio, we seem to have more than our fair share of the negative element.

When you come into this community, all bright-eyed, excited, willing to learn, you might be astonished just how negative some community members can be. You might pick up a special friend who follows you around, either on-air, or on-line, rarely in real life, who makes it their mission to make your life a misery.

This behaviour manifests itself with statements about the unsuitability of your license, your equipment, your gender, your knowledge, your examination process, your chosen frequency, your selected mode, anything that's not to the liking of whomever challenged your existence.

This kind of behaviour is known as gate-keeping and in amateur radio it's rife. People with a chip on their shoulder, the size of Montana, with nothing better to do than berate new amateurs, tell them off, preferably as a means to explain to them why they should leave the hobby or are not worthy of being considered an amateur.

In addition to these delightful utterances, I regularly see sexist, racist and other content shared among our community that would not be condoned in the workplace, let alone in the family home.

Why do we as a community tolerate this extreme behaviour when in the rest of our lives this is strongly discouraged and can lead to severe consequences such as dismissal and legal proceedings?

In civil discourse we treat each other with respect and that should be there regardless of the environment, be it professional, the home, or in this case a hobby.

It's been said that for some people in amateur radio, their biggest life achievement was the gaining of their amateur license. The acronym FIGJAM comes to mind to describe some of those entitlement rich individuals.

So what do you do when you are confronted with a repeater troll, or told that you don't measure up because you don't know Morse, or some other denigrating statement?

Previously I would have advocated that you ignore it and move on. Often times you've done nothing wrong and there's nothing to be gained from arguing the point.

There's only one problem with that. There is no cost to the bully, let's face it, we're talking about bullies, minor or major, still a bully.

No cost means no disincentive, which means that the behaviour continues until the bully gets bored. Only problem is that you'll need to weather the storm while that happens. Not good for you, your mental health or the mental health of the people around you. That's not a good balance.

As a community it's our job, that is, my job and your job to call out this behaviour and to expose it for what it is, abhorrent, elitist, sexist, racist, gate-keeping. I've been told that this isn't real and that I should leave this alone and to that I say: No. This is my hobby too and I get to have a say about what kind of hobby community I'd like to be part of.

So, instead I think we as a community need to do something more active. I think we, that is, you and I, need to call out a bully when we encounter one. It does't have to be confrontational, however satisfying that might be, but it needs to draw a line in the sand.

For example, you might say something like this:

Thank you for your comment. I don't believe that it's in the spirit of amateur radio. Please stop.

It's not going to end the behaviour of the bully, but it does achieve some other things. If this is on-line, it will flag for future readers that something is amiss and on-air it will highlight to fellow frequency users that you're not OK with what's going on.

It does some other things as well. For you it will give you a sense of ownership of what's going on around you, rather than being pushed into the role of victim. It will also give the bully a statement that's neutral whilst indicating that their behaviour is unacceptable.

I think that the only way out of the keyboard warrior and repeater-troll hell we find ourselves in is to do something different, to make noise, to shine a light and to discourage bad behaviour.

One thing I can say from personal observation is that what we as a community have done to date isn't working. It's getting worse. We're alienating good people who want to make a contribution and we're doing nothing to discourage those who are sure of their position and are unapologetic about how they express that superiority.

Step up. Call it out.

Thank you for your comment. I don't believe that it's in the spirit of amateur radio. Please stop.

I'm Onno VK6FLAB

New Entrants are Everywhere

Aug 24, 2019 268


Foundations of Amateur Radio

New Entrants are Everywhere

The hobby of amateur radio has been around for a long time. It was here before I was born and it will be here after I become a silent key. The same is true for you. While there is a recurring discussion about the death of the hobby, the reality is that our community changes continually. People come and go all the time. Reasons for change are as varied as the number of people you care to look at, from interest through to family, from money through to time, from boredom through to excitement, from life through to death.

As our community fluctuates, our skill level varies. We see new people come into the hobby, bright-eyed and bushy-tailed, ready for a new adventure, at the same time we have people who are experienced, or jaded, or both, participating in the community and finding themselves answering the same questions over and over again.

What radio should I get? Is this radio better? How do I do HF? How do I get my license? Where is everyone? How do you participate in a net? Which antenna should I buy? What is a QSO or a QTH? How come this and why that? At some point I was that person and I have no doubt that at some point you were, or are that person.

The challenge in maintaining a semblance of community coherence is to balance the needs for new and aspiring amateurs with the expectations of those already in the community. How do you answer the same questions while staying fresh and encouraging, when all you really want to do is ignore the noise and get on with the hobby?

The answer is simple.

You need to recognise that the change in the hobby is fundamental. New people coming in, new technologies, new hardware, new modes, new rules, new customs, all of it is in flux all the time. It shouldn't be seen as a threat, but as par for the course, something that is part of our community and part of why and how we exist.

To draw an analogy with something else, cooking. We've been doing that for a while, some suggest as far back as 2 million years ago. Every day new people learn to cook, new people invent or reinvent recipes, cooking classes abound, television shows with competitive cooking, new ingredients, new tools, new techniques and relearned old methods, there's celebrity chefs, awards and the more you look at cooking, the more you understand how it changes and continues to change. In many ways cooking and amateur radio are the same.

The idea of teaching your child, or a friend, or a person on social media how to cook something is accepted as how it is and how cooking evolves.

In amateur radio we can do the same.

It's easy to dismiss silly questions, or to give snide answers, or to ignore new arrivals, but that's not something that grows our community, strengthens it, or broadens it.

Of course, how much you participate in this is the real yardstick of how much of an amateur you really are. Said in another way, if an amateur calls CQ into a dummy load, does anyone care?

One of the challenges as a new entrant into the community is to figure out where to go and how to learn more. It's never been easier than it is today, even if you think that it's hard. In a bygone era you had to go to a library, or to find another amateur, or go to a club to even know that our hobby existed, these days the access to our community is within reach for any person on the planet.

We have endless resources, in the form of web-sites, books, both electronic and paper, clubs, virtual and physical, social media, podcasts and articles such as this, video channels, and an endlessly growing and evolving community that cannot help but document its adventures and exploits.

Amateur radio today is as close as the nearest search engine and as far as you want to take it.

Never be afraid of asking a question and consider it a right of passage if a grumpy bugger tells you off for asking a stupid one.

The worst question is the one you never asked.

I'm Onno VK6FLAB

What's in a Watt?

Aug 17, 2019 240


Foundations of Amateur Radio

What's in a Watt?

We need more power. I'm giving her all she's got, Captain! She cannae take anymore.

I'm sure your Scottish ancestors are rolling in their graves right now, but in our community of radio amateurs we have a tendency to advocate the use of more power. More power fixes all problems and hides all sins.

Another way to look at that is to think of the station with more power as an aligator, all mouth, no ears.

Before you dismiss this as another avocacy for QRP or low power, let me point out that more power creates more interference, more potential for harm, more electricity consumption, more wear and tear and more cost.

Previously I've spoken extensively about QRP communications, making contact with 5 Watt or less, but let's have a look at how much less.

I've shared with you that I managed to contact a station on the other side of the planet with only 5 Watts, Perth to Cuba and for me that was proof positive that all this was possible, even feasable.

We're doing much better than that.

One measurement is to calculate how many kilometers per Watt you achieved. My example of 5 Watt between Perth and Cuba is the equivalent of 3592 km per Watt. The maximum distance to the opposite side of our globe is about 20,000 km and my contact did nearly 18,000 km.

If you think that's amazing, I should warn you, my contact was special, for me, but as low power contacts go, it's not that amazing.

The first solid state radio contact made across the Atlantic ocean managed over 76,000 km per Watt. That was on 18 September 1956. You'll find the radio on display at the ARRL Laboratory, together with the bug and station log showing the contact between Chelmsford, Massachusetts and Copenhagen, Denmark between Gus W1OGU and Bo OZ7BO, on a radio made of two germanium transistors and built by Gus W1OGU, Al W1OSF and Dick W1UBC, who built the diminutive gadget on a lark to see if they could Work All Continents with it.

If you can copy the 40 microwatt CW beacon run by the North American QRP CW Club, you too can join in the fun. The current record stands at just under 22 million km per Watt when Bill W4ZV managed to copy the code word OMAHA from the N2XE beacon from New London, North Carolina.

Just to be clear, we're talking about a signal that travelled the equivalent of 22 million km using 1 Watt of power.

If you think that was amazing, Pioneer 10 managed to achieve 1.3 billion, that's 1.3 thousand million km per Watt in 2003. Mind you, that record was achieved with a slightly bulky antenna, the Deep Space Network.

Are you ready for more?

The current record stands at just under double the Pioneer 10 record, just under 2.6 billion km per Watt. That was achieved by Dick KL7YU and Bill W7BVV who made contacts between Alaska and Oregon in December 1969 and January 1970. A distance of 2655 km using one micro Watt.

Yes, you can throw a Kilowatt at the problem, or you can take your time, do some work and have some fun with low power.

You can call it QRP, or you can call it just enough to get the job done.

I'm Onno VK6FLAB

It broke and now what?

Aug 10, 2019 325


Foundations of Amateur Radio

It broke and now what?

Imagine you're a new amateur. You've woken up in the middle of the night because insomnia seems like a good way to use amateur radio as an excuse to get on air and make some noise. You turn on the radio, key up the transmitter and the next thing you know it's dark. The breaker that powers your radio popped and there's no more glow coming from the hardware that's warming up your shack.

You get up, reset the breaker, tighten up your dressing gown and switch on your gear. You sit down and key up. Pop, darkness.

What do you do next?

The first thing to realise is that there is something wrong. That might sound obvious, the radio just tripped the breaker and it went off, but sometimes it's not that obvious, sometimes there's something wrong, but it's not nearly as clear as light and dark. For example, you might key up and the SWR goes high. You might not even notice if your radio is set to monitor the power output, or the automatic gain control that indicates how well your audio is going out.

The point is that noticing that something is wrong is a matter of paying attention. Just sitting there all dumb and happy, mashing the microphone is going to cost money or cost something else one day when you stop paying attention.

So, finding out what's wrong starts with noticing that something is amiss.

If you've been clued in that something is broken, and you're not standing next to your radio with a fire extinguisher, or tears running down your cheeks because you just blew up your new radio, you can move onto the next part of this little adventure.

One thing to note is that it's really easy to make it worse at this point. Making it worse arrives in all manner of different ways, pain, either physical, RF burns, smoke, sparks, or mental like the emptying of your wallet when it goes pear-shape.

The art of troubleshooting is the process of attempting to learn what's going on. Some people know instinctively how to do this, others just wiggle stuff, unplug stuff and hope for the best. Hoping for the best is not the best plan.

One of the most basic aspects of troubleshooting, of trying to figure out what's happened, is to document what you find. Write it down. I know you're going to skip this, but it's going to bite you and then you'll be sorry and I'll be here telling you that I told you so. So write it down. Be meticulous. In case you're wondering, you're doing this for your own benefit, not my sense of curiosity. If you measure a value now and it's 7 Ohm and you change something and then you measure again and it's 23 Ohm, if you didn't write it down, you'll never know. Especially if the two measurements are a week apart.

Next basic concept is to change as little as possible, preferably one thing at a time. That's easy for me to say while your reptilian hind-brain is currently attempting to decide between whom to murder first and how fast to run. There is a tendency during panic to wildly wave your hands about and fiddle with lots of stuff. The urge to do that is strong. Resist that urge with all that you have. Again, you're going to ignore that and I'm going to stifle my I told you so chant, but less is more. This is important. If you change two things, you've just doubled the possible causes. If you change three, there are now six different causes and if you change four things, we're up to 24 different versions of the problem. Keep it simple.

Third concept is to test things. The smaller the test, the better. For example, you're connected to the right antenna, right? The power supply is giving out the right voltage, right? The squelch is open, right? The microphone is plugged in, right? Test each of those, one at a time. The more you troubleshoot, the more this list will come naturally. Right now you're probably cursing me for not supplying you with a ready-made list. That's because my shack is nothing like yours, not even a little bit. Also, your shack keeps changing. Besides we're learning the skill of troubleshooting and I already know how to do that. Mind you, truth be told, I've been known to make mistakes too, so there's that.

Forth concept is about testing gear. There is a tendency within our community to buy gadgets. The more the better, a volt meter, an ohm meter, an ammeter, an SWR meter, an oscilloscope, a VNA, a what-ever. The more toys the better. While toys, uh tools, help, they're not the answer to every question. You have a more fundamental issue to deal with. Garbage in equals garbage out. If you measure ohms, but needed volts, there's no helping you. So, instead of focussing on what new tool to acquire, focus on what measurement you need to make to prove that something works, or doesn't.

The process of troubleshooting doesn't come naturally to everyone. I know, I've seen some very panicked people break some very expensive hardware, seen full-bright scholars make bonehead mistakes and heard stories of physicists narrowly avoiding electrocution, so don't be shy when you say that you're not sure how to really do troubleshooting.

You can learn. We all did, me included.

I'm Onno VK6FLAB

What's in a word?

Aug 3, 2019 309


Foundations of Amateur Radio

What's in a word?

When you join a new community you learn very quickly that each community has its own language. A word in one community has a different or extra meaning in another. For example, the word "Snowflake" in one community might refer to a phenomenon related to water and freezing, in another community it refers to a person who is sensitive, easily hurt and offended. If you mix the two meanings all manner of misunderstanding ensues.

In amateur radio, one of those words is the word gain.

This word is used in many different aspects of our hobby, but today I'm going to focus on one specific use of it, in relation to antennas, antenna gain.

This mythical property of an antenna is often used as a way to distinguish two different antennas and in advertising terms, bigger is better, more gain, more better. I'll skip over the marketing shenanigans related to artificially making the number larger by comparing apples and pears, or dBi and dBd and move on to how gain comes about.

Let's look at something completely different. A light bulb. One of those tiny ones you find in a torch, or on the front of your bike or even one in your car. In essence we have a gadget that emits energy in the form of light and heat when electricity is applied. The specifics aren't important, but let's just say we're going to ignore more voltage and more amps for the moment.

If you have a bare light bulb, light and heat radiates in almost all directions. You can't see any light where the fitting is, but everywhere else is a pretty uniform pattern. For the moment, let's ignore the fitting.

If you were to get a piece of black cardboard and drill a hole and put the light through it, you've essentially removed half of the light. Below the cardboard there is no light. Above the cardboard is the same amount of light as before. Half the light is being stopped by the cardboard and it's essentially lost - technically it's getting absorbed and the cardboard is getting a little warmer, but let's not confuse the issue for the moment.

If you were to make the cardboard reflective, say some foil, white, a mirror, whatever, the light that was hitting the cardboard would be reflected away from the cardboard and you'd experience that as the light getting brighter. Notice though, it's still dark below the cardboard.

In essence you've just increased the gain of your light bulb and it didn't cost you any more electricity to make that happen.

Antennas work in much the same way. There are a few more wrinkles. A light bulb is working with light and heat frequencies, wavelengths are between 100 micrometers and 100 nanometres, where the antennas we use in amateur radio typically look at 100 meter to 23 centimetre, so the material aspects of our mirror equivalent are different, but have a similar idea.

One thing that's fundamentally different between a light bulb and an antenna in our hobby is that a light bulb is generally only transmitting, where we tend to both transmit and receive with an antenna.

Remember when I skipped over the bit of the light bulb below the cardboard being dark? That's the antenna equivalent to not hearing something, which means that you're better able to hear the signal in the direction you're pointing. The same is true for the bit about the light bulb fitting and no light below it.

In antenna terms, this phenomenon relates to the front-to-back ratio. Imagine turning your antenna 180 degrees. Pointing one way the signal is of this strength, pointing the other way it's that strength. Divide the two. If they're the same, the front-to-back ratio is 1, otherwise they express the directivity of the antenna. Another number you can use to market your antenna to an unsuspecting amateur.

So far we've only looked at using a single reflector for our light bulb, but if you were to use a torch, you'd get even more directivity and more gain. The same amount of energy, pointing at a smaller area. The ultimate expression of this is a laser beam, which is essentially a single focussed beam of light with no light anywhere other than where it's pointing.

Antennas do the same thing, using different methods, but the most common one is to add more bits of metal to focus the radio energy.

A light bulb emits energy in all directions and an antenna does too. Even if you were to make an antenna made of elements, all aligned in the same direction, the pattern is still mostly round, that is, it's like a cone of radio, regardless of the shape of the antenna.

Yes, there are ways of making antennas that don't make round cones, but that's a conversation for another day, but think about this, what would happen if you were to squash an antenna pattern and then focus it?

I'm Onno VK6FLAB

How far can I talk on radio?

Jul 27, 2019 273


Foundations of Amateur Radio

How far can I talk on radio?

A question that regularly hits the enquiring minds of people who are not (yet) radio amateurs is one about distance. For both amateurs and those who are not ye) inducted into our community the concept of distance speaks in ways that other parts of our hobby don't. It's a simple concept, between these two points, how far can you talk?

The interesting thing to me about this phenomenon is that distance isn't a metric that we as amateurs use for anything other than calculating repeater coverage and then only for frequencies that are line-of-sight. If you're not an amateur then this might be unexpected or even illogical.

Let me give you two questions:

How far can you talk in amateur radio? - and - How far does light shine?

If you're an amateur you'll know that those two questions are pretty similar, if not identical for certain frequencies, but if you're not, then these two questions appear completely unrelated to each other.

Let me start with something that you might not realise. If you tune to a local AM radio station, let's say ABC 720 in Perth. It's located in the AM broadcast band and the number of the station, 720, is the frequency at which it's transmitting. 720 kHz, or 720 thousand Hz. If you had a radio capable, you could turn the dial to the right, and after passing 810 Radio National, eventually, if you kept turning to the right, you'd find ABC Classic FM at 97.7fm in the FM broadcast band. The station indicator, 97.7 is again the frequency, 97.7 MHz, or 97.7 million Hz. So, 720 and 97.7 are both on the same dial, just at different ends.

Now if your radio was capable, you'd be able to keep winding it to the right, and after passing by Wi-Fi, at 2.4 GHz, or 2.4 billion Hz, you'd eventually come across light. Green light for example is about 560 THz, or 560 trillion Hz. You could keep going and end up with even more exotic stuff, like X-rays and Gamma-rays, in the exahertz range, a 1 with 18 zeros, but you get the point. Radio and light are the same thing. If fact, there are experiments around that are using light for Wi-Fi communications.

So, How far does light shine is the same thing as How far can you talk in amateur radio?

Before you start complaining about when it's different, let me point out that the only difference between these two is the frequencies at which we're comparing, with the characteristics that come with that. I'll get to that in a moment.

Look at light.

If you have a light bulb that's bright enough, you can see it in full daylight. If it's dark outside then you'll need less of a light bulb to see it. If it's raining, or if there is smoke in the air, you'll need more. If there's a wall between you and the bulb, you'd need a pretty bright light to shine through the wall, but you already know this. Covering up a torch with your palm shows the bones in your hand. Light gets through different parts of your hand in different ways.

Another thing you've seen is when you put a straw into a glass and it looks like it's broken. That too is related to how light travels through different materials. You may even have been underwater in a pool and looked up to see a reflection. That too is a phenomenon familiar in amateur radio.

Something that you might not realise is that something like an X-ray is identical to shining a light of a torch through your palm. Only X-ray's are used for diagnostic purposes, we shine an X-ray light at your body and some gets through and some doesn't. We take a photo of that and use it to figure out what's under your skin.

Back to radio.

The same phenomena happen in radio. Buildings are good at stopping certain radio frequencies, in much the same way as they block light, but other frequencies barely get noticed, they shine right through. Similarly, the ionosphere around the earth can act as a reflection like the surface of a swimming pool for some frequencies, but not for other frequencies. Interestingly this changes throughout the day, depending on the sun and a whole range of other factors which I'm not getting into today.

Finally, just like with light, you can turn up the brightness for different effects, you'll get further, but only if the conditions allow for it.

To answer the original question about how far you can talk on amateur radio becomes much harder and now you know why.

I'm Onno VK6FLAB

What's allowed on our bands?

Jul 20, 2019 320


Foundations of Amateur Radio

Recently there was a discussion on social media about the legality of various types of transmissions. Before I get into the specifics, it's worth looking at some of the rules around this. I will point out that this isn't exhaustive, but it gives you an idea of what I'm talking about.

In Australia, the rules about this are encapsulated in the Radiocommunications Licence Conditions Determination, referred to as the LCD. It essentially says that you must not operate an amateur station to transmit signals that are encoded for the purpose of obscuring the meaning of the signals, except for amateur satellite and repeater command and control purposes or emergency service operation and training.

In the United States, the rules are covered under the FCC rules, Part 97 Amateur Radio Service. It says that you may transmit using a digital code who's technical characteristics have been documented publicly. It goes on to prevent such transmissions for anyone communicating with a country that doesn't have an agreement with the United States. It also states that using unspecified digital codes must not be transmitted for the purpose of obscuring the meaning of any communication and if it's deemed necessary, you must maintain a record, convertible to the original information, of all digital communications transmitted.

In the United Kingdom, the amateur terms say that the licensee may use codes and abbreviations for communications as long as they do not obscure or confuse the meaning of the message and messages shall not be encrypted for the purpose of rendering the message unintelligible to other radio spectrum users, except for during emergencies or if used by various emergency or government departments.

Just by looking at three different sets of rules we can already tell that law makers across the globe have different ideas of what's allowed and what isn't. I will point out that the rules in the United States are much more prescriptive than those in Australia or the United Kingdom. I'll leave it to lawyers to determine which of the rules is more effective and what their actual effect is on our global amateur community.

Let's get back to the original question. What's allowed?

The purpose of obscuring the meaning of the message is essentially not allowed. What happens if that's a beneficial side-effect? Is that allowed?

For example, let's imagine that I have a new mode that is more efficient than any other mode in getting information between point A and point B. It does this by transmitting a single number, which is simply sent and received, it could even be done with Morse code.

Station A knows what the message means and Station B also knows what it means. How they come to a common understanding of the message is something I'll leave to your imagination, but is this kind of transmission in violation of the idea of obscuring the meaning of the message, if all we're doing is making communications faster?

Let's say that we have a public web-site that links those numbers we've exchanged to a more meaningful message. Let's say that Station A uploads an image to this website, and then sends an ID number of that image to Station B, which then goes to the same website and looks up that ID and sees the image. Bingo, transmission complete. Message exchanged. It's all public, there's no intent to obscure the meaning, everyone happy. In case you're wondering, I've just described how Hybrid EasyPal works.

What happens if I require a password to access the website to see which file was intended for me? Have I just obscured the meaning of the message? Note that I'm talking about two stations exchanging a unique identifier of some sort, that both stations have agreed on, so they can communicate via a password protected website using amateur radio.

That appears to be in violation of the amateur radio rules for all three countries.

It gets better.

What if I build a gadget that makes squeaky noises and knows how to receive them? Station A plugs their microphone into the gadget and talks into it. The gadget makes squeaky noises and those are transmitted. Station B has the same gadget, which understands squeaky noises and makes it into perfect audio. The purpose is to get information between the two stations, no intent to obscure the message, right?

What if I only make two of these gadgets?

The purpose isn't to obscure, but the outcome is that the messages are actually obscured. At this point we get lawyers involved who argue both sides. Your honour, I wasn't trying to hide my communications, I was just making them more efficient.

Clearly this isn't what our hobby is about. It's about exchanging information, un-obscured information, between stations that want to talk to each other.

If the intent is to make apples, but the outcome is that you're making pears, you're making pears.

I'm Onno VK6FLAB

Your Software Defined Radio around the home

Jul 13, 2019 296


Foundations of Amateur Radio What would you do if you found that at random times your garage door opener didn't work, or the Wi-Fi network dropped out, or you couldn't switch off a light with an RF controller? That's the position I found myself in and the times at which this was happening were madly unpredictable. One moment everything would work fine and the next all things radio would just stop. As a radio amateur you're likely nodding your head and thinking, radio interference, there's some direction finding in your future. Sure enough, that's the case, but before that, I needed to know if the interference was random, if it had a particular pattern and how widespread it was, since it seemed to impact multiple different devices using different parts of the radio spectrum. Initially I focussed on getting a recording of it. I turned on my radio, tuned it to a 2m frequency and recorded the noise. Only one problem. There was no noise. All I could see was an extreme signal strength, but it wasn't showing up as noise. I enrolled the help of my RTL dongle and recorded some raw data, essentially capturing a 3 MHz slice of noise centred around 147 MHz. All that revealed was that there was noise. I already knew that. At that point I decided that a bigger hammer was needed. Something you can do if you have a $5 RTL-SDR dongle and some free software, in my case I used a tool called rtl_power and a visualisation tool called gnuplot. rtl_power is a nifty piece of software. It takes measurements and averages out the power level across the measurement range. To make it work, you specify a starting frequency, a stopping frequency, how big a step to use to average, how often you want to measure and for how long. For my little investigation I started with measuring between 0 and 1.7 GHz, at 1 MHz intervals, every 2 minutes for 10 days. That creates a big CSV file that you can process with gnuplot into a picture that tells a thousand lies. Seriously, it showed me that the interference was very wide, 0 to 300 MHz, it occurred every 20 or so hours, lasted up to six hour at a time. There were other things happening as well, similar patterns, but across an even larger frequency range, from 0 to 600 MHz, but in shorter duration and of lesser strength. Based on the times alone, I can immediately, almost certainly, eliminate any source under my control. Based on the timings I can also determine that the noise is likely not created by an automatic process, given that they vary in duration and the way they're clustered around specific times. The variation of the interference allows me to determine that there are at least three separate types of noise, each with specific characteristics and times, sometimes overlapping. It's too early to tell if this pattern will continue. One possible next step is to set up the same measurement tool and powering it from a battery. Once I've got that working, I expect to turn off the house power during an interference session and determine if the noise is coming from my house, or if it's an external source, which seems likely. Once I've determined if it's in house or not, I can start either eliminating gadgets by switching off specific power circuits, or I can start direction finding and locating a nearby source of pain. At that point I can decide what to do next. That said, at the moment it looks like several televisions around me are creating an RF noise storm of epic proportions. I've documented all of how I did this and you can find it and the scripts I created on the web at vk6flab.com. One thing that has happened since I started documenting my efforts is the idea that we could collectively as a community make measurements like this and document the state of our RF space and how it changes over time. I plan to update my code to incorporate this idea, perhaps log in 24 hour blocks and generate a chart over that time, perhaps make it into a video. One challenge ahead of us would be to come up with...

The Software Defined Radio vs. Traditional Radio choice

Jul 5, 2019 227


Foundations of Amateur Radio For some time I've been explaining how some of the internal workings of a Software Defined Radio operate with a view to getting into the nitty gritty of the why and the how. This exploration is happening within the context of a world where there are countless choices for selecting a radio to match your budget. Increasingly that selection process starts with a simple question: Should I purchase a Software Defined Radio or a traditional radio? This is not a new question, previously it may have been: Should I select a radio with transistors or one with valves? Presumably the same happened when your ancestors faced a choice to buy a new car or update their horse and carriage. Of course I'm being flippant, but the point stands, as things evolve, choices change. Today we don't know what comes after the Software Defined Radio that we currently know, but it's likely to force the same selection on future generations of radio amateurs. So, if you're in the market for a new radio, what things should you consider in your selection? SDR is becoming pervasive, that is, the more you look, the more you'll find. Much like transistors overtook valves, not because they're better, but because there's a smaller component count and related price advantage. SDR come in all forms, from nondescript black boxes to a traditional radio form factor and everything in-between. If you choose a black box model SDR, there are tools around that allow you to use external controllers to provide knobs and buttons. These external controllers might be a fully-fledged radio head, or it might be using an external USB connected knob to change the frequency, or you might integrate your solution with a DJ Console, a big panel with lots of knobs, sliders and dials, repurposed as a user interface for your radio. The software behind most SDR platforms appears to continuously be in a state of rapid development. This means that every update potentially gives you more functionality. Of course the opposite is also true, things break, get taken away, get redeveloped, in ways that may be unexpected or unwanted. In my opinion, there's an awful lot of crap software around, attempting to use a computer screen to emulate a physical environment, forcing you to use a mouse to turn a knob, or slide a slider. It's getting better, but so far I've not seen a single solution that does this all well. That's not to say that there aren't any innovative things happening either. For example, something I've mentionned in the past, is the user interface for the diversity receive function inside PowerSDR. You set the phase angle and the strength by pulling on a line inside a circle. There's plenty of open source software around, and functionally it's pretty good. Fortunately Windows is not your only option, Mac OS and Linux provide many opportunities. Traditional radios have not finished, nor are they likely to go the way of the Dodo anytime soon, but while people are getting excited, you can pick up bargains from those migrating away from traditional radio to SDR. If your selection is based on using a computer or not, there's things to use your computer for with a traditional radio, numerous and growing digital modes and other cool stuff to get your teeth into. I should mention that there are radios about that are both traditional and SDR, so you can have the best (or worst) of both. My recommendation is to set a budget and see what that buys you. Regardless of what you end up with, your requirements will evolve. I'm Onno VK6FLAB

The Regulator

Jun 29, 2019 272


Foundations of Amateur Radio From time to time our hobby changes. While the idea that we're all a bunch of old men playing with spark gap transmitters, or using strange noises to the annoyance of others, the reality of amateur radio is markedly different from that stereotype. The changes we experience come from many different sources. As amateurs we're always trying something new, inventing things and building stuff. That type of change is integral to the hobby and in many ways it's why our community exists in the first place. Other changes are external. A new product arrives into the marketplace and we gleefully take possession of a new gadget. That in turn creates other changes which are incorporated into our day to day life as amateurs. A more structured change happens when the regulator makes a proposal, instigates a new rule, enforces an old rule or does something else that affects us. In the time I've been an amateur, I've seen changes happen that originate from the regulator that both benefit and impede our activities. Things like the introduction of new bands, the trial of high power, but also the removal of frequencies, the restriction on modes and across the globe this happens in every single jurisdiction. For example, in Sweden the regulator proposed and then implemented a reduction in transmitter power, from 1 kW down to 200 Watt. I'm sure it made lots of noise in Sweden, but here in Australia there was hardly a squeak. In France proposals have been drafted to reallocate the 2m band to the Aeronautical Mobile Service, to be discussed as an agenda item at WRT 2023. The 2m band is a band that is widely used, often as the first band for most amateurs, a band that offers local communication, hosts local discussion nets, has many options of affordable equipment, uses small antennas commonly installed on vehicles. In Australia the regulator is looking at removing access to the 3.6 GHz band for specific areas and defining more precise access restrictions, removing emission mode and bandwidth restrictions and removing specific Foundation restrictions, such as the ability to build radios, connect radios to the Internet and use digital modes. The Australian regulator is also of the opinion that any station should be able to use 400 Watts, regardless of the license level, since it's unlikely to increase interference. Interestingly, the local representative bodies are at odds with this, since they appear to believe that we need multiple levels of licence, even though I've never actually heard a coherent argument to support that. There's more, but let's move on. What strikes me is that the benefits are celebrated and the impediments are bemoaned with hardly any thought expressed on how these changes happened and what brought them about. There are representations made by representative bodies, but most of that is at arms-length. We're a tiny community in the scheme of things, we always have been, but we have access to one of the richest resources available and we have a regulator who is required to consider our existence when new rules are made and old rules retired. In discussion with other amateurs I hear time and time again that making a submission is hard, it's a waste of time and takes too long. For me that makes no sense. The notion that our tiny community has no impact is not credible in the face of the evidence, so why is it that the idea of making submissions to the regulator is such a waste of time and so difficult? Why is it that we give up before we even start? What is it in our DNA that leaves these submissions to others and what is it that makes us think we're unworthy or unable or unheard of if we never even try. A submission doesn't have to be a book, it doesn't need to have more than one page. You can write a letter to your regulator that says: Hey, I'm an amateur, I'm affected by your proposal and I think the following. My point is this. If amateur radio is important to you, if it gives you...

From Milk to Direct Conversion in a Software Defined Radio

Jun 22, 2019 287


Foundations of Amateur Radio It seems my analogy with milk glasses hit a nerve when I explained some of the inner workings of a simple Analogue to Digital Converter, also known as an A/D Converter or ADC as part of my exploration into Software Defined Radio. Thank you for your comments, suggestions and corrections. I did make an error when I said, grab eight of them and you'll have a byte, I'll get into that. Thank you for pointing it out. With my milk glass analogy, if you missed it, without naming it, I drew a picture explaining how a flash or direct-conversion ADC works. Briefly, I said that if you were to pour milk into a glass and continued to do that until you ran out of glasses or milk, you'd have converted a signal into bits. I also covered how a partially filled glass was neither full nor empty and if you ended up with milk all over the desk you wouldn't know how much there was. In terms of electronics, how does this actually work? In essence you're comparing a reference voltage against your incoming antenna signal. The way that happens is you have a series of resistors between ground and your reference voltage. For simplicity, lets say five identical resistors against a reference of 5 Volts. The result is a series of steps of voltage. At the first resistor the reference voltage is 1 Volt, at the second, it's 2 Volt and so on. If you were to compare your antenna signal at the first resistor, you'd compare it against 1 Volt and your antenna signal might be higher or lower. If it's higher than 1 Volt, we'd record a full glass or one and if it's lower we'd record an empty glass or zero. This is done with a nifty circuit called a comparator that compares two voltages. If the signal is higher than the reference, it returns a one and if it's lower, it returns a zero. If that sounds familiar, an op-amp does a similar thing and if you're wondering, a comparator is an op-amp without a feedback resistor. In a circuit diagram you might see a triangle with two voltages coming in, the one you're measuring and the reference voltage with a single output that's either zero or one. Inside that triangle, which you can purchase as a component for cents, you'll find the whole circuit that makes all this happen. I'll acknowledge there is an opportunity here to go into how an op-amp actually works, how it slightly differs from a comparator and more, but we're talking about an Analogue to Digital Converter, which in turn is part of a discussion about how a Software Defined Radio works, so I'll leave the circuit diagram and building an op-amp from basic components for another time. One thing to note though is that this type of ADC is essentially independent of frequency, it's a direct-conversion ADC and the speed of sampling is determined later on in the process. Back to comparators. We have several of these, each comparing the incoming signal against a stepped reference voltage. In actual fact, if you're doing 8-bit sampling, you'd need 255 of these comparators, if you're sampling at 16-bits, you'd need 65535 of them. As I explained with glasses of milk previously, you'll have interesting results if the voltage you're measuring is between steps. You could increase the number of steps and measure more accurately, but as I said before, you're only kidding yourself if you think that solves the actual problem. In the same way, if the voltage you're measuring is higher than the total reference voltage, you're up the creek without a paddle and you won't know what happened, unless you saw magic smoke appear, in which case you know that lightning probably struck somewhere nearby. You could increase the reference voltage, like making the glasses bigger, but that's actually making it worse, since we now have bigger steps between each measuring point. So, a flash ADC is a series of comparators which compare an incoming signal against a reference voltage and returns a series of bits that digitally represent your signal. The final...

Milking Software Defined Radio

Jun 15, 2019 196


Foundations of Amateur Radio One of the unsung hero components of a Software Defined Radio is the A/D or Analogue to Digital converter. Its job is to convert the analogue signal that's coming in via the antenna into a digital signal that is processed by software. I've talked about the difference between analogue and digital before and many explanations talk about converting things into zero and one. There are a few steps before that. Imagine a row of identical glasses, let's say eight. Grab a jug of milk and pour it into the first glass. Keep pouring until it's full. Now do the same to the second glass, rinse and repeat until you either run out of milk, or run out of glasses. You now have either a row of glasses full with milk and some spilled all over your desk, or you have some full glasses and some empty ones. Now if you were to mark a one on your logging paper for every full glass and a zero for every empty glass, you'll end up with a row of zeros and ones. Essentially you've converted an analogue signal into a digital one and in effect, this is how an A/D converter works. Each glass represents effectively what's known in computing as a bit. Grab eight of them and you have a byte. I will point out that this is just one example of an A/D converter, there are many others. You may have noticed I've skipped over some interesting things here. For example, what happens when you spill your milk all over the desk? Or what happens if you don't completely fill a glass? This is the bit where the action is. So, let's look at that. If you've ever over driven a microphone or a speaker, heard of clipping, or distortion, those are all equivalent to spilling milk all over your desk. The take-away is that there is an indeterminate amount of milk and no place to store it, so your row of glasses says all full, but you and I both know that there is some spillage. This is lost information, we don't know if there is a droplet spilled or a whole ocean spilled. So, one consideration in picking an A/D converter is how to deal with high signal levels. You may need to either increase the number of glasses, or bits, or you may need to decrease the signal before measuring it. Another interesting thing is what happens at the boundary between full glasses and empty glasses. If you pour one glass full and run out of milk, you're good to go, but the reality says that you'll start pouring the next glass and you'll run out, having a glass that's only half-full. Or is it? Is it half-empty? How do you know? Is this glass represented as a one or as a zero? You could create a row that's twice as long with glasses that are half the size, and at the boundary you'd have a more accurate idea, but you'd still have the same issue, is the glass that you filled only partly, half-full, or half-empty? There's more to come, but the basic idea of converting an infinitely variable signal coming from your antenna into something used by software is a big part of a Software Defined Radio. I'm Onno VK6FLAB

When digging gives you more understanding, the magic of software.

Jun 8, 2019 320


Foundations of Amateur Radio Today I'm going to go sideways to move forward. In amateur radio we consider circuits, components such as transistors, inductors, capacitors, crystals and how they're connected to each other. The framework in which that exists is embodied by the field of electronics and how these components can be mixed together to shape a radio that you can build or buy. In a software defined radio there are electronics and components to be sure, but the bulk of the work is done in the field of software and today I'm going to look at that. Computers surround us, in our work place, in our home, on the street, in our hospitals, across our society. Each of these devices is running a thing called software, as opposed to hardware - a physical thing, software is intangible, in much the same way as your date of birth is intangible. You cannot hold your birth date in the air and point at it. You could write it down onto a piece of paper and point at the piece of paper that has the date on it, but you'd be pointing at a piece of paper, not your actual birth date. Computers work in much the same way. You cannot point at software, nor can you hold it in your hand. You can print it out onto paper, and point at that, but you'd end up with a deforestation problem that far exceeds the stripping of all the trees in the Amazon rain forest. To make matters more complex, there are at least two types of software, human readable and computer readable. You can translate human readable source code into a computer readable executable with a tool called a compiler, but doing it in the other direction is much harder. Think of the ink on the paper that describes your date of birth. You can put the ink on the paper, but putting it back into the pen is more complex. All this is leading somewhere, I promise. A little while ago I started digging into how Software Defined Radios work and if you've been following along on my journey, there'll be parts that you can follow, parts that you sort of get, and bits that seem like black magic. This will be different for each person. My black magic is not going to be the same as yours and the things I understand without thinking might make your head explode. If that's not enough, the goal posts keep moving. As I said, I started digging, much like peeling an onion, removing layer by layer, I've been exploring and learning and hopefully sharing my excitement along the way. The other day a mate of mine came by with a new toy. A QRP or low power HF radio. The device itself is entirely driven by software, that is, it's a Software Defined Radio. It has some knobs and buttons, a display, a power socket, a plug for a microphone, an antenna, a speaker port and some other bits and pieces, but underneath all that is software. What's special about this radio is that the software is Open Source, that is, you can peek inside and see what the code looks like before it becomes ink on the page, the human readable source code, rather than the computer readable executable. I've touched on Open Source before and perhaps I should spend some time on that soon, but for now, think of it as a set of rules that dictate how you are allowed to use source code. As any self-respecting IT geek, I went to the website where the software is available and downloaded it. What struck me was that it was much simpler than I had expected. Don't get me wrong, this is a complex piece of software, not something I'm expecting to pick up in an hour or even a week, but it's simple - as in digestible. I can point at different bits and understand what they do. This part does Morse Code, that does FM, over here is RTTY and look, over here is FreeDV. If you're wondering, I'm describing the UHSDR, or Universal Ham Software Defined Radio project. Built originally by Chris M0NKA and Clint KA7OEI and sporting an impressive list of contributors, this software offers insight into receiving and transmitting using an SDR across a variety of...

Software Defined Radio offers another path to the same information.

Jun 1, 2019 304


Foundations of Amateur Radio Over the past few weeks I've been describing how some of the fundamental concepts of software defined radio work and how some of these operate and interact with each other. You might think of some of these ideas and technologies as unrelated to the hobby of amateur radio, or not relevant to traditionally built radios. Nothing could be further from the truth. Before I go on, I've been trying to find more elegant terms to distinguish between radios built with mostly software and those built with mostly hardware, and I use the word mostly, because a traditional radio like my Yaesu FT857D has software on board and similarly the software defined radio Flex 6600 has traditional components inside the box. For convenience, until I find a better distinction I'm going to refer to these as hardware radios and software radios. When I refer to a hardware radio, think Yaesu FT857D, when I say software radio, think Flex 6600. Back to the topic at hand. The techniques used in both disciplines, hardware and software, apply to each other. So for example, a band filter might be useful in both and use similar if not identical circuitry, but a noise filter, or an audio filter like a Collins SSB or CW filter might only exist in a hardware radio and the software radio deals with the issue using little programs. Similarly, the local oscillator in both determine the accuracy of frequency representation, but a hardware radio might require a screwdriver to adjust, where a software radio offers the adjustment functionality with a single menu option. With my time spent on software defined radio, I'm finding that my understanding of how spectrum relates to the signal and how filters, offsets and various adjustments all relate to each other. Don't get me wrong. The things I'm learning are perfectly able to be represented within hardware radios and the education that goes with that, what I'm saying is that they arrived for free for me with understanding the software defined radio. Let me give you an example. If you listen to a Morse code beacon signal on the 10m band, lets say the NCDXF beacon on 28.2 MHz. If your radio is set up correctly, you'll hear a tone as each beacon does its thing. If you tune slightly off frequency, the tone changes, up or down, depending on how you've got your radio configured. If you've got a Collins CW filter, you might find the whole thing vanishes if you stray too far off frequency. Now here's the thing. The tone you're hearing is actually dependent entirely on how far off frequency you are, so much so, that if you're entirely on frequency, you won't hear anything at all. But you just heard me say that if your radio is set up correctly, you'll hear Morse if you're on frequency, and that's because, setting up the radio includes an offset, in a hardware radio it might be called the CW pitch, and what it does is essentially take your radio off frequency by the pitch amount. You can test this by setting the pitch to 0 and taking the radio off frequency by say 500 Hz. The point is that how this works and my understanding of it, came entirely from the software radio side. My training didn't include the intricacies of hardware radios, but my curiosity got me there by another path. Another way to consider the Morse code signal is to think of it as a tone of 0 Hz. You can't hear the tone, since it's 0, but if you were to move the dial, the 0 changes into something you can hear. While I'm at it, if you've ever wondered what's the difference is between the two CW modes on your radio, when they don't appear to do much at all? Consider two signals, side by side, say 500 Hz apart. From a listing perspective, the station you care about is at 500 Hz and the one you don't care about is at 1000 Hz. Change to the other CW mode and the one you care about is still at 500 Hz, but the other station has moved from a 1000 Hz to 0 and it vanished. I've spoken to many different amateurs over the years...

Digital Origami in Software Defined Radio

May 25, 2019 271


Foundations of Amateur Radio As a quick recap of what I've discussed before, a Software Defined Radio is a tool that essentially measures the voltage at the base of an antenna system and sends that to a computer for processing. The faster you measure, or sample, the better the representation of what's coming in via the antenna. The traditional view is that you need to sample at least twice as high as the highest frequency you want to represent. You may also recall that an antenna system doesn't just receive a single frequency, the one your radio is tuned to, but all frequencies. So, if you need to build a software defined radio from scratch, your first question might be: What do I want to listen to?, followed by: Which sample rate do I need? If we were to answer the first question with HF, say up to 50 MHz, the answer would be something like a sample rate of 100 MHz, so you can capture any signal up to 50 MHz. So, twice the highest frequency as the one you care about, that's the short way of waving your hands about and ignoring any little inconvenient side effects. Like, what happens to signals above 50 MHz? First of all, your antenna system will still receive those signals to more or lesser degree, they don't just vanish because your sampling tool isn't interested in anything over 50 MHz. The second thing that happens is that the signals between 50 and 100 MHz will turn up backwards between 0 and 50, so you'll effectively hear 51 MHz at 49, 55 MHz at 45 and so on. As a neat little side-effect, for those reversed signals, an upper side band signal will turn into a lower side band signal and vice-versa, but I'll leave that for another time. In case you're wondering, yes, this can be a desired effect. The signals between 100 and 150 MHz will also turn up where they're not welcome, 105 MHz becomes 5, 110 MHz becomes 10 and so on. A different way to picture that is to think of a tri-fold birthday card. Lay it flat on the table, put a 0 in the top left, 50 at the first fold, 100 at the second fold and 150 in the top right. You're looking at 0 to 150 MHz. Now fold it up. You'll notice that 0 and 100 are in the same place and 50 and 150 are also in the same place. If you need more detail, put some in-between numbers, 25 MHz, 75 MHz and 125 MHz and you should see what's happening. I've seen it described as digital origami and it is. The technical term is called aliasing and it's also referred to as folding. It happens in day-to-day life as well. If you've ever seen a wheel running backwards on television or on a film, that's an example of folding. If that's not enough, this phenomenon repeats itself, 150 to 200 MHz is overlapped in reverse, 200 to 250 MHz overlaps normally and so on. You might come to the conclusion that your magic SDR isn't so magic any more, now you have all this other stuff turning up that you don't want to hear. So what do you do? One approach is to increase the sample rate, but as I've explained, it doesn't make the problem go away. But here's the thing: If you were to sample at say 200 MHz, you'd be perfectly fine with any signal up to 100 MHz. Now here's the kicker. If you filter out anything above 50 MHz, and as long as there's nothing left by the time you get to 100 MHz, you're good to go, no more unwanted information, no more aliasing or folding. Essentially what you've just done is created a thing called a bandwidth limited system. You've essentially removed anything above 100 MHz and now your sampling is working as planned and all of the stuff I've said about sampling at least twice the maximum frequency applies. Yes, there's more, but I'll get to that another time, but to give you a taste, what happens if you want to use the same SDR to listen to the 2m band? I'm Onno VK6FLAB

SDR: How many colours inside a Software Defined Radio?

May 17, 2019 398


Foundations of Amateur Radio SDR: How many colours inside a Software Defined Radio? If you were asked to make an image of the Sydney harbour bridge and only use four dots, the viewer might struggle to determine what was the bridge, the sky, the water and the Sydney Opera House. Regardless of the number of colours available to you, the number of dots would not be enough information for most people. You might have a nice piece of art on your hands, but it might be ineligible for the Archibald prize. Even if you were allowed many colours, and just four dots, figuring out if the blue dot was water, sky, or the background of the Australian flag on top of the bridge might be just as complicated. If you were asked to make the image with one hundred dots, and only use black and white, from the perspective of the viewer you'd have a result that was easier to understand. Use a thousand dots, even easier, even if you only used black and white. Now, if you were to use a hundred dots, with ten colours, your image might be just as easy to understand as if it was a thousand dots in black and white. The point is, there are two things going on here. The number of dots and the information contained in each dot. More dots or more colours, or both, will help your image. Similarly, in Software Defined Radio, more dots, that is, more samples, will help and as I've previously mentioned, you need at least twice the number of samples as the highest frequency that you're measuring. But what of the colours in relation to an SDR? Measuring voltage as a human with a piece of paper is pretty straightforward. Provided you've got a Volt meter, a piece of paper and a scribble stick, you're good to go. If you measure your voltage as 1 Volt, you write 1, if it's -1 Volt, you write -1. Similarly, if it's 100 Volts, you'd write 100, 13.8 Volts and you'd write 13.8. We'll get back to colours in a moment. Provided your paper is big enough, you can record as many values as you need and as accurately as you desire. 13.8 or 13.8853, makes no difference to a piece of paper. Computers represent numbers internally using powers of two, called bits. A single bit can represent two values, 0 and 1. Two bits can represent four values, 8 bits represent 256 values and 16 bits represent 65536 different values. The takeaway is that there are a specific number of values that you can represent inside a computer, depending on how many bits you use. Consider the values I've mentioned, 1, -1, 100 and 13.8. That's four different values. If it's not immediately obvious, what ever solution you come up with, tracking positive and negative, tracking small and large, whole and fractions should all be part of the mix. In case you're wondering, we're essentially describing here how many colours or values we are going to allow, or in terms of a computer, how many bits. Let's consider all the values you might measure and represent inside a computer. How many different voltages do you want to be able to record between 1 Volt and 100 Volt? If you allow for ten values, you can record 10 Volt, 20 Volt and so-on, but you can't record 15 Volt. If you allow for a hundred values, you can record 1 Volt, 2 Volt and up, but you won't be able to record 1.5 Volt. If you account for a thousand values then you can record 1.1 Volt, 1.2 Volt and so-on, but you can't record -10 Volt. Remember, our computer representation can only manage a specific list of values and the size of the list is determined by the number of bits you're using. The rabbit hole goes even deeper. Radio signals vary massively in their strength, which is why we use a decibel scale to represent the signal strength, instead of saying station A is a thousand times stronger than station B, we say it has a signal level that's 30 dBm higher. That's comparing a 1 Watt station to a 1 kilowatt station, and in terms of voltage, that's between 20 Volt and 632 Volt. If you're designing a mechanism to store your measurements inside...

SDR Sample Rates: How fast is fast enough?

May 11, 2019 337


Foundations of Amateur Radio SDR Sample Rates: How fast is fast enough? If you measure the voltage at the base of an antenna and record the readings, you end up with a collection of numbers that represent the voltage over time. These numbers, or samples, can be used to represent the antenna signal inside a computer. An antenna system voltage is an example of an analogue signal, continuous over time, the recorded readings, the samples are an example of digital, discrete and intermittent. It's possible to reconstruct an analogue signal from digital samples and that's exactly what Software Defined Radio or SDR is all about. The process of sampling essentially converts a continuous signal into an intermittent one. As recording separate samples implies, there is loss of information in this conversion. For example, if you sample once a minute, you'd represent a continuous signal as 60 samples per hour, probably enough to reconstruct where you've driven in your car along the highway, but hardly enough to reconstruct the route through the middle of the city, let alone represent an antenna signal that varies millions of times per second. So, how often do you need to record a sample? Turns out that if you sample at least twice as fast as the highest frequency you're representing, you're good to go. So, for sound, the human ear can hear about 20 kHz, so more than twice that, explains some of why a CD is sampled at 44 kHz. If you want to represent the 20m band, up to 14.350 MHz, you need at least a sample rate that's double that, or 28.7 MHz. As an aside, there are other ways to look at this problem. If you managed to move the 20m band down to 0, then you'd only need at least a sample rate of 700 kHz to do this. Let me say that in a different way. The width of the 20m band is 350 kHz. So sampling it would require at least twice that, or at least 700 kHz. Moving frequencies around is something that we've been doing in traditional radios for a long time. The technique uses one or more frequency mixers. This means that combining some traditional radio tools with an SDR gives you even more options. Truth be told however, this idea of moving the band with one or more mixers is becoming less important as technology improves and there are plenty of reasons not to use this. I'll talk about that at another time. So, the first takeaway is that to sample a continuous signal and be able to represent that signal accurately requires a sample rate that's at least twice as high as the highest frequency in the continuous signal. Without going into the actual proof of this, consider a sine wave that oscillates at 1 Hz. If you sample it at anything less than 2 Hz, you'll end up with some cycles being sampled only once, which isn't enough to represent the sine wave. If you sample it at exactly 2 Hz, you'll have two samples on every cycle, but if you happen to sample when your signal is 0, all you'll ever measure is 0. By sampling at a rate greater than 2 Hz, you overcome that limitation. I'll make brief mention of another phenomenon, that of over sampling. An interesting thing happens if you sample twice, three times or more than the minimum sample rate. In short, the higher sample rate improves the dynamic range, noise performance and filtering, all very useful when you are processing radio signals. Cheaper and cheaper hardware are making this very attractive and it explains some of the reasons why SDR manufacturers are using sample rates that far exceed double the highest frequency being sampled, for example, the Flex-6600 samples at 245.76 Mega Samples Per Second, or Msps, even though the maximum receive frequency is between 30 kHz and 54 MHz. In case you're wondering, yes, I'm leaving out a lot of detail here, one thing at a time. The opposite, under sampling, has its uses as well, but I'll also leave those for another time. The second takeaway is that higher sample rates are used to reduce cost, increase performance and reduce...

Software Defined Radio is fundamentally a different way of looking at radio spectrum

May 4, 2019 311


Foundations of Amateur Radio We think of radio as operating on a specific frequency. We select an antenna resonant on a single band. We configure the radio for that same band and then turn the dial or the VFO, or Variable Frequency Oscillator to a particular frequency within that band. All of our language is geared towards this concept of tuning, of picking out, selecting one special tuned, resonant frequency and listening to it. I've said this before, but that's not actually what's happening. Your radio is receiving all RF frequencies, all of them, all at the same time, all the time. Your antenna is better at hearing some frequencies than others, but that doesn't stop it from hearing everything at once. Your radio is getting all that RF information at the antenna connector. After that, every step along the way is removing unwanted information, first it removes all the bands you're not listening to, then the VFO selects which part of what remains to let through to the decoder and the result finally arrives at the loudspeaker. Ultimately, all your radio lets you play with is what's left over. Say about 3 kHz bandwidth. Using traditional radio, if you want to listen to two repeaters, you either need to switch back and forth quickly, or you need two receivers. Now without going into how precisely, imagine an SDR with a bandwidth of 3 MHz, one thousand times larger than your traditional radio. Before you think I'm being fanciful, a $25 gadget can do this. This means that you could process most if not all of the 2m amateur band and then pick out which bits you'd like to decode. You could decode all the local FM repeaters, an overflying satellite, the International Space Station SSTV, a beacon, Morse, Packet, RTTY and simplex contacts, WSPR, APRS, EME, whatever is happening on 2m, all at the same time. Let me say that again. All of the 2m band, all at the same time. The point is that all this information is there, all the time. We can opt to decode or ignore the information. In a traditional radio, you can only decode one signal at a time, but on an SDR, you can extract as much or as little as your computer can handle. Some SDR language talks about using multiple receivers, but a better description is multiple decoders. This means that software defined radio is fundamentally a different way of looking at radio spectrum. Instead of filtering out everything we don't want to decode, we select which decoder to apply to which part of the spectrum. With an SDR you could represent the 2m band as a 3 MHz slice of spectrum as a series of measurements. There is no loss if you reuse the numbers, so if you process the same data multiple times, you have no loss of signal, no deterioration, no extra noise. All we do is feed the same data into each decoder, pick out the bit we want to decode and have at it. There is a misconception that you need serious computing power to do this. That's not strictly accurate. A $5 Raspberry Pi single board computer is more than powerful enough to do this. You can argue that this is serious computing power, compared to what we used to land on the moon it is, compared to your mobile phone, it isn't. I fully intend to go into the maths behind this, but it's not scary, despite what you might think or have been taught. My week has been about the maths and it's become clear to me that there are lots of explanations around, each trying harder than the next to scare you away. If you feel the need to run screaming for the hills when you hear the words Nyquist, Shannon and Fourier, then get it out of your system and come back when you're ready. I'd like to mention that I've been working on how to explain this over much of the week, I've lost count of the number of drafts I've written, but it keeps coming back to the words that are almost as old as I am: My god, it's full of stars. No doubt you might be convinced that I've lost my marbles and that I'm going well outside the Foundations of Amateur Radio,...

How does a Software Defined Radio or SDR work?

Apr 26, 2019 330


Foundations of Amateur Radio If you've been around the hobby in the past decade, you may have come across the invention of a Software Defined Radio, or SDR. You might even own one and if you've looked into how it works, read the explanation that essentially describes it as a traditional radio where all the components are implemented in software. To me that's like explaining how a radio works by waiving your hands and saying: here is magic. How it actually works is something all together more interesting and thought provoking. If you think of sound, like my voice, coming from a speaker, you can imagine putting a volt meter on the speaker terminals and measuring every second what the voltage is. As my voice gets louder you might measure a large voltage, as I take a breath, it will be smaller. You could chart the different measurements and show a waveform that would represent the loud and soft parts of what I'm saying. The faster you measure, the more accurate the picture represents my voice. For comparison, a CD player does this measurement 44 thousand times per second. If you were to play back those sound measurements at the same rate into a speaker, you'd end up with my voice, and that's actually more or less, what's happening if you're listening to this podcast. Yes, for the purists, there's more to it, but not relevant at this point. Similarly, if you were to hook up a volt meter to an antenna and take measurements, you'd end up with a chart that represented the signal strength that your antenna is receiving and the faster you measured, the better the representation. What it exactly represents I'll come to in a moment. The waveform that represents my voice is actually a very complex signal. In much the same way as a piece of music is made up of different notes, played in sequence and in concert with each other, my voice is also made up of separate frequencies, played together to form the words that you hear. If you were to measure those separate frequencies and draw a waveform for each, you'd see how every one contributes a little to the overall effect, and if you were to add them all together, you'd have my voice again. In the same way, the waveform that represents an antenna signal is made up of all the separate frequencies that go into the overall signal. You might be surprised to learn that an antenna is actually hearing all frequencies at the same time. Some better than others, but typically, all of the RF spectrum at any given time. Your radio is also essentially hearing all frequencies. When you tune to a local station on 720 kHz, you're actually telling your radio to ignore all the stuff that isn't 720 kHz and to only process that small bit of what it's hearing. The selectivity of a radio is the measurement that represents how good your radio is at being deaf to all the things you don't want to hear. To help that filtering, a traditional radio and antenna works by pre-selecting part of the RF spectrum, when you press the AM button on your car-radio, you're selecting which chunk to listen to, press the FM button on the same car-radio, you'll select another chunk. On an amateur radio, you select by choosing the 80m band, the 40m band, etc. Similarly, your antenna is pre-disposed to hearing a particular chunk better than others, but that doesn't make it immune to signals across the entire range. You may have heard described that a Software Defined Radio hears all frequencies at the same time. Essentially it's a volt meter connected to your antenna, spitting out measurements as fast as it can for processing by a computer. The waveform that comes from those antenna voltage measurements represents all of the RF spectrum and it's just the beginning of what you can do next. In the same way that my voice is made up of lots of different parts, all played together, the RF spectrum is made up of the local broadcast stations, the local TV stations, mobile phones, garage remotes, Roy on the 7130 DX net, this podcast...

Antennas out of sight and out of mind ...

Apr 20, 2019 254


Foundations of Amateur Radio Previously I've spoken about the dynamic nature of your station. Even if from day to day use, nothing changes, things around you are always in flux. Propagation changes, power fluctuates and the environment in which your antenna operates is dynamic. Mobile stations even more so. A few days ago we had a gale come through, strong enough to do some major damage, rip off some roofs, break some trees, cause flooding, cause power outages, plummeting temperatures, the first of the Winter Storms. Obviously, checking out your antenna after such an event is expected. Better still, stowing your gear before the event is even better. Such extreme weather events are an obvious trigger to attending to antenna health and well being, not to mention, maintenance and repair. The thing is, it's not the only time you should check out your antenna. Every day it's subject to change. The sun rises in the East, follows its path along the sky and eventually sets in the West. The temperature and humidity change throughout the day and continue to change through the night and the next day it starts all over again. Peppered with sun, rain, snow, salt, corrosion, expansion and contraction, your faithful antenna sits there ready for you to get on air and make noise, until one day it isn't. You could just wait until it falls down, dies, perhaps becomes a hazard to anyone within gravity range, not to mention, destroy your radio when you key it up. Or you could check your antenna regularly and look after it. Inspect and test it regularly, run you analyser across it every couple of months, you know the drill. Most antennas are out of sight for most of their life, but they should never be out of mind. During the weekly F-troop net we started discussing this - as well as an in depth conversation about launching wire into trees - and there were several suggestions worth investigating. One amateur pointed out that the level of complexity in the air dictates the amount of maintenance. A log periodic antenna on a rotator needs more Tender Loving Care than a wire hanging off a tree. Another suggested that you should regularly check the tower supports - technically the mast supports - a tower is self-standing and a mast is not - the best way to remember is that is the Eiffel Tower doesn't have any guy wires. Before a storm, if you have warning, you should check the supports, wind down anything that goes up and down and you should think about how you're going to earth the coax. I've previously covered the weirdness that lightning and charge represents, even at distance, so don't wait until it's overhead. There were suggestions of using spark plugs and Mason Jars, but I've got no supporting evidence either way. My geek background is sceptical, but I'm open to learning more. I've seen installations where a coax switch is used where the antenna is switched to a shorted socket, so the inner and outer braid of the coax are connected to each other. One amateur suggested that an antenna tuner is cheaper than a radio, and that if you leave it in place during a storm, blowing that up is cheaper than blowing up a radio, but your mileage may vary. Also, if you have spare cash to burn, I'm happy to take your donation and relieve you of that fire hazard. It's interesting in and of itself that antenna maintenance is often discussed in terms of extremes, lighting, storm, wind, ice, etc. and less so in terms of regular maintenance. Finally, if you're only using a temporary antenna, you're not exempt from this. You're actually likely to have more failure, since the act of erecting and lowering of the antenna is likely to cause more wear and tear. The antenna is the final part of the transmission chain and it should be treated with the same respect as the power supply at the other end. I'm Onno VK6FLAB

Fragility of Communication

Apr 13, 2019 275


Foundations of Amateur Radio Our day to day life is full of communication. We listen, although less and less, to the radio for news and entertainment, sometimes mixed together as food and games for the masses. We can communicate with family, friends and the rest of the global population using a telephone. With the internet as a transmission medium, we exchange text, sound and vision with impunity to anyone who stumbles across it on a mind boggling collection of outlets, websites, social media, email, streaming services to name a few. The vast majority of this kind of communication is a commodity, that means that with little or no training most of the population has access to this. Another aspect of this commodification is that it's reliable. It works most of the time, it's generally good quality, with little or no loss, as in, you speak into your phone and there's an extremely high chance for the other party to hear your voice. While there are occasions that calls drop out, or the audio is chopped up, it's more an exception rather than a regular occurrence. In stark contrast, amateur radio is none of those things. It's not a commodity, it's not reliable, it's a poor man's version of the ubiquitous mobile phone. As amateurs we know why it's not the same, for starters, to make contact between say Perth and Bermuda using amateur radio requires exactly two pieces of equipment. Your radio and theirs. Making this contact with a mobile requires that both ends have a phone. They'll also need a way to connect to the phone network, either a local base station or a telephone exchange, those in turn connect via many different ways to each other, including repeaters, relays, perhaps a satellite, a fibre optic cable or three, too many devices to count today. Extreme level of complexity. I'm mentioning this because it's simple to conclude that amateur radio is obsolete, but its just not true. With the lack of reliability associated with an amateur radio connection comes something that is unique to society today. Thanks to reliable communication, we have come to expect that all communication is reliable, even our experimental hobby, but if you spend any time on air at all you'll quickly realise that for amateur radio, we need to conduct ourselves with protocol, using specific procedures, phonetics, structured phrases, callsigns and the like to overcome some of the aspects of unreliability. Talking on the local repeater looks and smells like a mobile phone chat room, but it's not. It relies entirely on the participants collaborating to ensure reliable communication. Similarly, calling CQ on HF, requires that you understand that the other station isn't on the end of a telephone connection and that parts of what you're saying are going to be missing at the other end. Using phonetics, speaking slower, waiting longer and monitoring, all assist with making contact. If you're unsure about this, just listen in on a local net for regular confusion, or use an online receiver like WebSDR to hear what you sound like at the other end. To make things a little more interesting, every amateur band has a different failure mode. On 20m from one breath to the next, the path might close, on 80m you might get overwhelmed by noise, on 40m you might find yourself all of a sudden sharing the frequency with another station, both of you blissfully unaware of the other's existence. Communication in amateur radio is collaborative and there are common courtesy behaviours. If you're working a rare DX station, that's not a personal friend, don't start a whole conversation about your dogs, your medical issues, or the level of amazingness of your station. You're not alone in attempting to make the contact and they're not there for your personal enjoyment. Hogging the frequency is a sure fired way to acquire the ire of your fellow amateurs, especially in marginal conditions, where band conditions are rapidly changing. There is nothing like getting your feet...

When you hear a distress call ...

Apr 6, 2019 244


Foundations of Amateur Radio When you hear a distress call ... When you get your amateur radio license you become part of a select group of humans who are required to notify authorities if you happen to hear an emergency transmission. Not only that, you're required to offer assistance. The regulator in Australia, the ACMA, says this about it: When a distress call is heard, you must immediately cease all transmissions. You must continue to listen on frequency. You must record full details of the distress message, in writing and if possible recorded by tape recorder. You must also wait for a short time to see if the message is heard by a station better placed to help. If the distress message is not acknowledged within a reasonable time, the amateur is obliged to assist. The regulator goes on to say that after acknowledging or attempting to acknowledge receipt of the distress message, you should immediately forward details of the distress situation to the nearest police station for land based distress situations or the Australian Maritime Safety Authority for air or sea based distress situations. In the United States, the ARRL uses the word may, rather than must, but essentially says the same thing. The FCC, the US regulator, says that an amateur station is not restricted by any rules to attract attention in the case of distress, nor is there any restriction on assisting a station in distress. In the UK, the regulator specifies that instead of waiting for a reasonable time you must wait for three minutes for a Coast Station to reply before responding. Interestingly, getting information on how to respond, what you must and must not do is hard to come by. This in itself is a cause for concern, but let's move on. Using the Australian example and requirements, how prepared are you to do this? Could you actually record the information, do you have a pen and paper next to your radio and can at short notice dig up a tape-recorder, or presumably some more modern recording device, capable of recording audio from your station? Do you have have the contact details for search and rescue at hand and are you actually prepared for such activities? During the week, an amateur in Australia reported that they heard a distress signal five hours after the event. While they were at work, their station recorded off-air and they listened to the recording after returning home. Using social media, they asked the question, should they report this information to authorities? The answer is Yes, not only should they, in this case, given that they're in Australia, they must. There was no evidence that any other station heard the distress signal, in fact, the evidence was that the other stations continued to transmit on frequency, either completely deaf, or engaged in more pressing activities like hunting for a contact. I will note that propagation is a fickle beast and it's possible, though improbable, that the other stations on frequency didn't hear the distress call, even through it was repeated. For that reason alone, you should never assume that someone else will deal with it and as I said, in Australia, you don't get the option, you are required to. A couple of other things came to light for that amateur this week. Their recording was in a format that was hard to process by normal audio processing software, in this case the recording was made as an I/Q recording, we should look at that some other time, but processing the file was non-trivial and valuable time was lost in uploading a huge file, and for others to download it for confirmation. There was also indecision about reporting the call to authorities and if so, to which ones. I will say that while we don't know the outcome of the distress signal, we do know that it was reported and that at this point is exactly what is required. The chances that you'll hear a real distress signal in your life are tiny, but if it happens, are you ready for it? I know I have some work to do. I'm...

Overcoming Microphone Anxiety

Mar 29, 2019 343


Foundations of Amateur Radio Overcoming Microphone Anxiety If the thought of keying up a microphone has you break out in a cold sweat, or the notion of making a mistake sends you into fits of anxiety, the idea of performance in public makes your heart pound, this is for you. Amateur radio is a hobby of communication. The lowest barrier to entry is a hand held radio and making voice contacts with the rest of the community. There is an underlying assumption that this is likely to be the most common way that you'll start getting on air and making noise. Of course you don't have to do that. You could learn Morse Code and never have to open your mouth. You could get a license that's permitted to use a Digital Mode like JT65 or RTTY and let your fingers to the talking. Both those options are perfectly valid and if that's what you need to get on air, be my guest. If you do however want to actually get to a point where you can communicate with other amateurs using voice communication, then let's investigate what voice communication actually entails and what fears might be eating away at your confidence. The most obvious fear, shared by many, if not most amateurs, is the fear of making a mistake. So let's look at that. Apart from blowing up your gear, which won't actually be noticed by anyone but you, those near to you and perhaps your bank manager, blowing up your gear is not a high embarrassment experience. Expensive perhaps, but not so much socially crippling, unless you tell someone that you did it. Other mistakes might be a little more public. For example, if you're on HF, theoretically the entire planet can hear you, perhaps even those space aliens orbiting the Sun and in 4.367 years, those orbiting Alpha Centauri. So potentially, many different individuals and communities can hear you. To counter that I'd point out that most of those will not actually have the means to hear you, or if they technically do, they are likely to be on a different frequency, or otherwise engaged, eating, sleeping, procreating, whatever. The chances that someone actually hears you is very, very low and if you're on VHF or UHF, the audience drops even further. The potential audience is only really line-of-sight, unless you happen to activate a Tropospheric duct, but then that might only double the potential audience, the actual audience is still a fraction compared to HF. You might be afraid that you'll transmit on the wrong frequency. If you've purchased modern properly built and configured amateur radio equipment, the chances of transmitting out of band, into non-amateur frequencies is very low. If you pay attention to what the dial says, and you have a copy of your band-plan at hand, the chances of getting it wrong are even lower. Even so, the band police aren't going to knock on your door within the next 30 seconds, so take a breath. The next set of fears revolve around saying the wrong thing. If you haven't talked on the radio much, or even at all, you're bound to worry about blurting out the wrong thing and being the biggest embarrassment to the hobby in this and the last century. Getting your callsign wrong is pretty common. If you're just starting out, or even if you're more experienced, writing down the callsign on a piece of paper and having it in front of you when you key your microphone is good planning. For every contest I participate in using anything other than my own callsign, I bring a piece of paper and a thick marker for just that purpose. I can still get it wrong, sometimes I even notice. Then there is the topic of the conversation itself. What do you talk about? How long do you talk? How much should you share? The answer to those questions can be summed up with a simple phrase - less is more. If you're establishing the actual contact, a bare minimum is required. You need to first establish that you have their callsign and they have yours. Don't do anything until both those have been confirmed. That goes for both...

The Station Log

Mar 23, 2019 391


Foundations of Amateur Radio The Station Log A topic that rarely if ever gets any serious air-time is the humble station log. It's a process where you track what contacts you've made with whom, when and what conditions prevailed at the time. Notice first of all that I mention that it's a process. A station log is made up of several different moving parts and if you're new to this you might think of your station log as a physical thing. You can actually buy things called Station Logs, looks like a book, it has pages, lines, columns, sometimes pre-populated with headings and as you operate, you write stuff into this book. Let's start with the stuff. What stuff? How much stuff? Have you ever heard another station on-air say something along the lines: Hey Wally, it's been a long time, we last spoke in 1984, how are you and how are the kids? If you thought for a moment that the station had all that information stored away in the back of their mind, that's not to say, some do, but most of the time it's thanks to their station log that this kind of information is at their fingertips. Another thing you might realise is that if you're using paper, like the book I mentioned, then doing this kind of lookup is less than trivial, unless you maintain two logs, one in callsign order and another in contact order. Perhaps you start creating a card file with this kind of information. We do have better tools. At the simplest level, you can create a spreadsheet with your station log. It's simple to maintain, easy to expand, backup, infinitely flexible and for many stations it ticks all the right boxes as a way to store contact information. So, looking at a spreadsheet, what columns should you introduce as a starting point? Well date and time is a good start. Logging in UTC is a solid idea, given that you might move location several times in your amateur career and you might not always be in the same time zone, so if you need to know what time it actually was, you'd need to add a time zone column. Instead just log in UTC, and the time will always be correct. After date and time, you'll need a record of the frequency. You can either record it as a band name, or as an actual frequency, your choice. You'll need a column for the mode, was it an SSB contact, CW or an AM contact, RTTY, FM, FT8, what ever you need to track. You can choose to differentiate between Upper Side Band and Lower Side Band, it's entirely up to you. The next column you'll need is a callsign column, one for the other station. If you have several callsigns, you might also want to add a column for your own callsign. The operator name, theirs, presumably you know who you are, a signal report sent column and a signal report received column and if you're game a comments column. That's the bare bones of the idea. You can expand this to include location information, both theirs and yours, perhaps you'd like to record station information, what antenna you were using, where were you, operating on battery, the power levels, etc. The sky is the limit. Log as much or as little as seems helpful. You'll notice at this point I've not yet talked about specific software. That's because at this point you don't actually know what you care about. For some people logging the bare minimum is enough, for others, recording the whole contact or QSO is not enough and of course there is every variation in between. Once you've become comfortable with what to log, you can start looking for specific tools, what's suitable for your Operating System, your usage patterns, etc. I've said previously that if you're looking at logging software, make absolutely sure that it has the ability to export your data. If it cannot export, then my strong recommendation is to discard that software as a choice, because locking away your data in a flexible environment like amateur radio is a recipe for entering data manually into a new tool and you have better things to do with your life like getting on air and...

What's in a Chirp?

Mar 15, 2019 210


Foundations of Amateur Radio What's in a Chirp? On Thursday the 3rd of July 2008 at 6 minutes to 7 at night a developer called Dan KK7DS started to scratch an itch and published the results. The next morning before breakfast Dan added more. Since then about a hundred people from around the globe have contributed to that project. Some people made little changes, others made large contributions over many years. In all, on average, the project saw a change every 29 hours over more than a decade of contributions. On the 16th of July, less than two weeks into the project, it got a name, CHIRP. It's been translated from US English to Spanish, French, Hungarian, Italian, Dutch, Polish, Brazilian Portuguese, Russian and the Queens English. From the beginning of talking to a single Icom IC-92 radio, CHIRP today supports 27 different Icom radios, 36 different brands of radio, hundreds of different radios in all, with new ones being added every couple of months or so. The software runs on anything that will run Python, that includes Windows, OS X and Linux and it does it with an extremely modest footprint and it's free, free in cost and free as in Open Source. If you're not familiar with CHIRP and you have a radio, then it's time to get to know this tool. It makes it simple to program your radio, to configure settings and to make backups of your current channel listings. I should mention that this is not just for hand held radios, there are plenty of HF base station radios supported. When you run CHIRP it presents you with a window where you have a spreadsheet view of the channels in your radio. You can download the channels from your radio or upload new ones. Changing a frequency is as simple as clicking on the frequency and typing a new one, with a full-human-sized keyboard, rather than the poor excuse for a dial-pad your radio has. If your radio supports it, you can supply a human readable name, configure offsets, CTCSS and tuning step size, the mode and several other properties. If you're unsure where to get started, CHIRP even comes with a list of frequencies to get you on your way. You can create different configurations for different types of operations. For example, if you're into SOTA, you can make a configuration file that has all the relevant SOTA frequencies, but when you head back home and want to use the local repeater network, you can build a set for that. If you visit a different state, another country, or if you want to copy your channels from one radio to another, you can with CHIRP. If you want to get started, there's a Beginners Guide, a list of frequently asked questions and you'll find information about what cables to use, specific errors and issues you might encounter and if you're a software developer, you'll find information on how to contribute. If you want the ability to program your radio on any computer, you can download a boot-able CD that will run CHIRP without installing it and if you need help, there's an active mailing list, going back to 2008, an up to date wiki, issue tracker and of course, you can download the source-code, if that's your fancy. CHIRP makes all that possible because one amateur wanted to scratch an itch. What's itchy in your life? I'm Onno VK6FLAB

Creativity comes with practice

Mar 8, 2019 249


Foundations of Amateur Radio Creativity comes with practice I grew up with Lego, plastic blocks that you can put together in infinite variety. My oldest Lego kit hails from 1964, kit 324: House with Garage and it's still in pretty good nick today. It's missing the tree and the car and the garage door is broken and a few blocks have vanished, but putting it together the other day reminded me of the art of building. Today I still play with Lego. In fact after a hiatus of several decades I pulled out my old boxes and started sorting my blocks. That lead to building the House and while I was at it, I managed to reconstruct my first Lego Technic kit, 850: Forklift, bringing with it a flood of memories. Why the Lego? It's been my source of inspiration for many decades. It has allowed me to imagine something and then go on to build it. Over the years I've learned that this is not a universal experience. I recall one friend who was gifted a huge Lego car, but had no idea that you were allowed to modify it and I blew his mind converting his four cylinder engine into a V6. That same eye for the possibility exists in all of us. You need to look at things in a different light. One of my friends likes to shop online, he also loves to roam through the local hardware store and I get regular photos of things that are useful. Last night I got a photo of a square washer. Plate of steel, galvanised, hole in the middle with the caption: I've got plans. I took one look at it and knew that I too had plans for that washer, which is why thoughtfully he bought a couple for me too - I didn't even need to ask, it was obvious to us both. The central hole is just the right size for an SO239, so clearly the washer is just right to act as an antenna base. You could weld it to a trailer, or drill some holes for radials, hang it from a tree, make a dipole from it, the sky is the limit and for only 76 cents, what's not to like. I've been looking, like all my amateur friends do regularly, for a pole. I have a large 12m squidpole. It's very helpful to make into a vertical antenna. Use a bit of wire and you're good to go. It's a little floppy if you want to hold anything more substantial, like a horizontal dipole or an inverted V antenna. So, back to the pole. I'm looking in my local hardware store for poles. Of course I could go with the Pine variety, but I'm not keen on carrying a 3.6m wooden pole on the roof of my car, or for that matter, several of them, so I've been looking for other solutions. Tent-poles, pretty cost-effective, strong if you can guy them and the load is vertical, there's painters poles, which will require some testing to see if you can combine several together and make a longer contraption. The point is, I'm not seeing a painter's pole or a tent-pole when I'm looking, I'm seeing the ability to hold something up. In the same way as when Calvin gets his hands on a large box and converts it into a Transmogrifier, I wander the isles of various shopping outlets looking for the possibilities that something might have, rather than the label written on the outside. Doing this is second nature, and achieving it is a matter of practice. The best advice I can give is to walk around with 'What-if' emblazoned on your brain. What-if I could use this as an antenna, what-if I could use this as a battery-box, what-if this fits into my car, what-if this table is big enough for a field-day, what-if. That same what-if attitude will stand you in good stead when you experiment with antennas. Don't be afraid of failing, the more you fail, the better you learn. What-if isn't scary, it's in-built into this hobby of amateur radio. I'm Onno VK6FLAB

All the power in the world and not enough battery!

Mar 2, 2019 296


Foundations of Amateur Radio All the power in the world and not enough battery! The transceiver you use to get on air and make noise needs power to operate. The traditional voltage for our amateur equipment is 13.8 Volts. Why not 12 Volts you ask. The short answer is chemistry, but let's move on, there is lots to cover. Generally that 13.8 Volt is specified with a +/- symbol and some percentage. For my radio it's 15%, which means that if I plug it into power that's somewhere between 11.7 Volt and 15.9 Volt, I'm good to go. Then when you look a little closer at the specification you'll see that my radio draws 22 Amp. That's a whole chunk of juice that needs to come from a power supply. Of course that means that you'll also need to deal with 22 Amp fuses, wire capable of dealing with 13.8 Volt at 22 Amp, and connectors that won't melt when you do that. If you look closer again, you might notice that 22 Amp is when you're using the radio at maximum power, that is, 100% duty cycle and 100% power, and only during transmit, in the case of my radio, 100 Watts for HF. So, if I'm using a digital mode, AM or FM, at 100 Watts on HF, my radio says it will draw 22 Amp at 13.8 Volts. Those numbers aren't correct of you're using CW or SSB. A rough number to work with for CW is 40%, that means if you're doing CW for a minute, that's the equivalent of key down at a 100% for 40 seconds and key up at 0% for 60 seconds. SSB is roughly 4 times as efficient as AM, about 25% duty cycle, but realistically it's more like 20%, since your power consumption depends on how much you're yelling into the microphone. If you take long breaths, 0% power, whistle into the microphone, 100% of SSB, or 25% of overall power. Now all this gets even more interesting if you consider that you're not just transmitting all the time. If you're only transmitting half the time, you need to take your power consumption down another 50%, so SSB might be 10%, CW only 20% and the digital modes 50%, from the perspective of the power supply. So you want to go portable and need batteries. Batteries don't come in 13.8 Volt versions. So 12 Volts. Get the number of amp hour and you're good to go right? Nope. Your battery doesn't just run at 12 Volts and then all of a sudden stop, it runs down, you've seen it in a torch or a Walkman when the tape got slower and slower. A 26 Ah battery should give you 26 Amp for an hour at 12 Volts, but if you actually do that, you'll need to buy a new battery, because you'll have destroyed the one you just exhausted. All of this then starts a conversation about chargers, which incidentally might put out 14.4 Volts. You might turn to solar panels, which at peak power operate at something like 18 Volts, then you stumble into the world of PWM vs MPPT solar converters or charges. Then there's the joys of over and under current, battery discharge rates, continuous versus intermittent charging, different battery types, battery safety, storage, weight, out-gassing and more fun than you'll want to know about on your morning commute. And I haven't even talked about battery isolation, HF interference from chargers and inverters, the differences between powering your radio straight from a battery or via a DC to DC converter, using 240 Volts, or if you're in the USA 120 Volts in the field, generators, compatibility with others and how much all this might cost and if you need to invest in lotto tickets to pay for this experience. One tool I stumbled across in my travels is the Four State QRP Group website which has the W1PNS / WA0ITP / AB8XA Battery Life Estimator, which in a single web page gives you the ability to say what mode you'll be using, for how long with what battery size and how much radio draw and it'll tell you how much more battery you'll need to get the job done. Very handy for a contest that you're hoping to operate portable from a battery. This all to say that power is a very deep rabbit hole and it will take you some time to...

More WSPR adventures

Feb 23, 2019 286


Foundations of Amateur Radio More WSPR adventures Previously I've spoken about the joy of making something out of not much. On that theme I've covered WSPR, the Weak Signal Propagation Reporter, a mechanism to use a modest station to report signals received, which is something any suitably interested person can participate in, no license required. For a time I had my radio, a Yaesu FT-857D connected to a Windows XP notebook running WSJT-X, a piece of software that has the ability to set the frequency of your radio and then listen to what the radio is hearing, attempt to decode it and then report on what was heard. The beauty of this system is that you're using your own station to report signals heard, that is, your own antenna, your own coax, your own radio. Essentially you can use it to see what can be heard from around the world at your station. I had this running for a while, but the set-up was less than satisfactory, because I use the same radio and antenna to run weekly nets, the computer was running Windows XP and running out of disk space since WSJT-X has the option to save all the audio heard, which was clogging up my drive. It also meant that I was required to remember that I needed to reset the volume of the radio, set the squelch just so, disconnect and more importantly reconnect the antenna when there were storms about and a few other annoyances that became just a little too much for it to be fun. After doing this for a couple of months I just gave up and put it into the too-hard basket. The other day I started afresh. I started with a Raspberry Pi. It's a single board computer, about the size of a credit card, that comes in at about $30, is powered off a USB adaptor and runs Linux. Since I've been using Linux for around 20 years now, it seemed like a natural fit. I managed to obtain an RTL-SDR dongle which if you're not familiar, is essentially a USB device that you can use to listen to RF frequencies. Without going too deep, these gadgets started life as USB DVB-T and FM receivers, you know the USB dongles that you can plug into your computer to watch free-to-air TV or listen to FM radio. Back in March of 2010 Eric Fry got curious about figuring out if he could make a Linux version for one of the dongles work by reverse engineering the communication between the dongle and the supplied Windows software. In 2012 Antti Palosaari built on that and published his findings on the linux-media mailing list. Things exploded from there. So, an RTL-SDR dongle, connected to a Raspberry Pi, running Linux. At this point it would be great if I could report success and show and tell everything I've learnt, but then for that to happen I would need to actually have had success and I'm not quite there yet. I managed to decode one, count 'em, one, WSPR packet on 6m, once. Of course I couldn't help myself and started to improve things and since then I've not heard anything. I can tell you that there is plenty of documentation online about the subject, and I'll be adding my version of that once I've got mine up and running. There's a few things to work on, for example, listening on 6m is all fine and well, as long as there are 6m stations within hearing that are on and transmitting. Turns out that the station that I heard once last weekend has been switched off for a week. I've just changed bands, to see if that improves things, but only time will tell. I have also been using a mechanism to change bands automatically every 15 minutes, but without any spots I'm not sure if my set-up is working or not and I've just been unlucky not to hear anything. The challenges continue, but then I suppose that's why I'm here in the first place. I will add that a problem shared is a problem halved. I mentioned my challenge to a local amateur who sprang into action and set-up a WSPR beacon, just so I can test against it. I'll let you know how I go, or you can monitor for my spots on the WSPR website and celebrate when you see a spot...

Modern Tools for a Modern Hobby

Feb 15, 2019 238


Foundations of Amateur Radio The hobby we call amateur radio is enormous. One amateur called it a thousand hobbies in one and that just about sums it up for me. Being bored inside this hobby is not an option, because there is just so much to do and see. Yesterday I found a completely unrelated aspect to our hobby, call it the one thousand and first hobby associated with amateur radio. A friend came over and handed me the separation kit mount for my Yaesu FT-857D, it's the bit of plastic that you clip to the back of the head of the radio, so you can mount it somewhere separate from the main body of the radio. I have one of those already, purchased from a local supplier, at the time, 8 years ago, it cost me $80, these days it's included with the radio. For my station I needed a second mount and I really didn't want to spend that much money on three cables and some plastic, so I went hunting for alternatives. One of my friends is doing some 3D printing R&D for his job and has access to a printer to do some rapid prototyping and I wondered if that might be an option. Turns out that I'm late to the party, people have been designing and printing bits for their radios for years. A quick hunt through the popular 3D printing libraries showed about 500 different designs for Yaesu, Elecraft, Baofeng, ICOM and Kenwood, though I should point out that Kenwood also makes food processors and other bits that seem popular in the 3D printing world, so 500 is likely a little high, but respectable nonetheless. I looked at 8 different libraries and found that Thingiverse is by far the most popular for bits with radio brands we know and love. It occurred to me that right here is thr perfect example of how amateur radio is a hobby that just grows and grows. If you're looking for radio mounts, stands, buttons, microphone clips, belt clips, mount adaptors, holders, cradles, plug covers, brackets, earpiece retainers, logos, callsign stands, cogs, gears, handles, caps, pins, latches, cases, tuning knobs, CW key brackets, stacking brackets, antenna adaptors, feet, desk stands, shoulder strap holders, battery compartments, you're good to go. I should mention that you don't even need to invest in a 3D printer at this point, you can hand the design to a printing service and get your print shipped to you in the mail. If you cannot find what you're looking for, you can fire up a 3D CAD program and get designing to make something precisely to your own specifications and based on the current tools available, you can even see what it's going to look like by the time it's rendered in the plastic and colour of your choice. I've only mentioned radio bits, but there's nothing stopping you from printing ladder line separators, dipole centres, antenna brackets, tuner cases, project cases for your home-brew contraption, knobs and dials, buttons and connectors and other missing parts or hard to find pieces. If you're using standard components like a Raspberry Pi or Arduino, you'll find cases ready to go for those as well, so the more you look, the more you'll find. The point of all this is that amateur radio is a hobby that goes far beyond someone sitting behind a radio listening to beeps, pops and crackles. Manufacturing and amateur radio go hand-in-hand and have done since the very beginning, but there's no rule that says that you have to keep using traditional tools to build what you're imagining. The sky is the limit, and based on the efforts of CAMRAS, the CA Muller Radio Astronomy Station, PI9CAM based at the Dwingeloo Radio Telescope in the Netherlands, who captured a photo of the far side of the moon using a camera linked to an amateur radio transceiver on board of the Chinese Longjiang-2 satellite, even that limit is being explored. I'm Onno VK6FLAB

How effective is your station?

Feb 8, 2019 312


Foundations of Amateur Radio How effective is your station? We tend to spend most of our energy looking at antennas and power to evaluate how well our station works. Based on a better antenna or more power, you're likely to make more contacts is the general gist of the process. Being a QRP operator, power rarely comes into the conversation, 5 Watts is what you get, leaving antennas as the prime method of discovering how effective we can be. Recently I received an email from Layne AE1N, pointing me at an article he wrote on the Nashua Area Radio Society website titled: It's all about the decibels - factors in enhancing station effectiveness. The article, goes into great detail in looking at an alternative way of measuring how well you're doing and builds on the December 2013 QST article - How Much Punch Can You Get from Different Modes? In our hobby we measure using a thing called the decibel. I've spoken about it at great length previously. The way to use it is to compare something against something else. Using the metric used in the QST article we take as a starting point a modern transceiver, using 100 Watts, CW into a half-wave dipole at 30m. Everything we're discussing from here on in, is related to that starting point, the zero point. I should also make clear that we're talking about the ability of the receiver to decode your message, not the strength of the signal. If you were to use the same radio and instead of using CW, used AM, you'd have a station that was 27 dB worse off. That is, your signal would effectively become harder to hear by 27 decibel. On the other hand, you if were to replace the half-wave dipole with a 4 element Yagi, your station would be just under 7 dB better off, that is, it would be easier to hear you by 7 dB. Of course you can combine AM and the Yagi, adding the two measurements together, coming out at minus 20 dB, which means that compared to a 100 Watt transmission on CW into a half-wave dipole, the same 100 Watt transmission on AM into a 4 element Yagi would still be harder to hear by 20 dB. If you go from CW to SSB, you'd be 17 dB worse off, or SSB is 10 dB better than AM. Note that when I say better and worse, it's about how much your signal can be decoded at the other end, using the same receiver, antenna, etc. The whole article includes comparisons between CW and FM, CW and RTTY and so-on. RTTY is only 4 dB worse than CW, but most transceiver manufacturers recommend that you reduce power to a quarter power, that is, 25 Watt instead of 100 Watt when using RTTY or Digital modes, so you end up losing 14 dB for that, making RTTY slightly worse than SSB if you follow the manufacturer instructions to reduce power. This isn't all doom and gloom however. Even though CW is very effective, we can improve things in other ways. For example, using PSK31 gives you a 7 dB head start, switching from CW to JT65 or FT8 gives you 25 dB. Even if you take into account the reduction from the loss of full power, 14 dB, you still end up in front by 11 decibel, which is more than you can get from upping power from 100 Watt to 400 Watt which only gets you 6 dB. Adding an 11 element Yagi gives you a similar improvement as changing from CW to FT8, just over 11 dB, and using 1500 Watts is only slightly better at 12 dB. The point I'm making is that you can use this idea to figure out how to get your signal heard. More power or a bigger antenna is only part of the conversation, picking the correct mode is just as important. Of course, the 11 dB gain you get from moving from CW to FT8, even when reducing power, is one of the main reasons that it's so popular, much easier to change mode than to build a new fancy antenna. One more thing, what of the 5 Watts vs. 100 Watts we started with, 13 dB. That's significant, but if you were to use 5 Watts FT8 into a quarter-wave dipole, using 100% of the 5 Watts, you'll actually be 12 dB better off than the same station using 100 Watts CW. Check out Layne's...

How to select a mobile operating location

Feb 1, 2019 303


Foundations of Amateur Radio Operating your amateur radio station at home, in your shack, is one of the often discussed aspects of our hobby. Much has been said about installation, antennas, grounding and the like, but what if you want to operate mobile? Picking a location, of all the locations available to you, can be quite the task. For some it's daunting, others find it challenging, others take to it with ease and often you find yourself overwhelmed by choice. What makes a good operating location, what should you look for and how do you do this better? First thing to consider is that options give you choice, choice gives you uncertainty, which can lead to stress and other unpleasantness. If you're completely flummoxed as to how to select a location, visit the Summits On The Air website, or the World Wide Flora and Fauna site and see which of the qualifying locations is reachable for you. The choice becomes much easier if you don't have a choice. Picking from a proscribed list makes it easier to start and the more you do it, the more you'll learn about what makes a good operating location and what doesn't. Restricting your options is one path to success, but there are others. Over the years I've poured over maps, looked at places that qualified, tried and failed, many times. Things I look for when I am hunting for a new place to operate from include the ability for my car to get there. I live in Australia, often shade is a consideration, away from buildings and other sources of interference. I tend to go for places that have water nearby, preferably the ocean, but I also frequent lakes and rivers. If I'm operating on VHF and UHF for a local contest I might look for a high point, something that has clear line of sight to the local amateur community, in my case a high hill or the local ranges overlooking the city basin. For one contest I needed to visit local shires and to do that I created a map showing all the shire boundaries. I then used that map to scout possible locations and took into account how to get from this shire to the next. I learnt from that exercise that the ground beneath the operating location matters, sand versus gravel, gravel versus granite, granite versus swamp. I also learnt that overhead power lines are hard to spot on a map, but avoiding them is essential to success. Depending on how long you plan to operate for, an hour, a day, the weekend, select a location based on the time that you're there. Picking an isolated jetty where there is potential for crime in the middle of the night is probably best for day-time activations, but might need reconsideration for an overnight adventure. Picking a local park might be possible for 24 hours, but the local ranger might not appreciate you setting up a more permanent camp. Often planning works to your advantage. The local council might appreciate you having a chat with them before a contest and might even offer you assistance in the form of local facilities, running water, etc. Consider using the local public open space with a community hall as your base. There's a balance to be found between preparation and turning up on the day. If the location is something that you're only visiting for an hour, you won't need to scout, unless you're planning on a particularly elusive DX contact, but setting up camp for 48 hours with tents, masts, coax and operating positions will benefit from a visit before the actual event. Make sure that you bring along a radio that can operate on the bands that you're planning to operate on and remember to turn it on and have a listen. I can tell you that driving for 90km to scout a location and forgetting to actually turn on the radio is an experience that I cannot recommend. There are many places to choose from. Radio considerations aside, I mentioned shade before. The environment is important. You don't want to set-up on the side of a highway with fast moving traffic, or in a location where people will come right up to...

Brand New Callsign

Jan 26, 2019 257


Foundations of Amateur Radio Today I have a new callsign, it's exciting, special, kind of strange, to be known as something other than VK6FLAB. It's hard to overstate how much of your identity as a radio amateur is linked to your callsign. It's a strange phenomenon to those who are not amateurs, or who have only just joined the community and are still learning to remember what callsign they have. We think of callsigns as semi-permanent fixtures, but realistically they're far from that. In your life as an amateur you'll operate many callsigns, even if you never change your own. When you're operating the local club-station, you'll use that callsign, or when you're participating in a special event, say an activation of an island, or some remote DX station, or when you get on air to make noise in another country. Some stations use special contesting callsigns, either for speed, or to commemorate another amateur. There are those who collect callsigns like badges, others only ever register one and keep it for the rest of their life. There are provisions for applying for callsigns for short duty operation, sometimes as little as 24 hours, to mark a significant event or activation. For example, in 2013 we registered VI6PROF as a special callsign for the then Chief Scientist of Western Australia, Professor Lyn Beazley, who used that callsign for two hours after dinner during the annual conference held in VK6 that year. There are callsigns registered for marking the end of Polio, VI6POLIO, 100 years of the Wireless Institute of Australia VI100WIA. VK100MARCONI commemorated the first direct wireless message from the UK to Australia. There are callsigns registered for activating an island, like VK6WDI to activate Woody Island between the 9th and the 12th of November 2012, or VK6CHI for the Cheyene Island activation in 2007. Special callsigns are a global phenomenon. The Straight Key Century Club operates K3Y. K1A gets used by amateurs throughout the USA for many different events, from Boy Scout camps through to the America Recycles Day, from the Georgia QSO party to the ARRL Field Day. The 2012 Olympic Games in the United Kingdom were celebrated with 2012L and 2012W callsigns. RG22RQ was for the Winter Olympic Games in Sochi. As with anything rare, there's an active community that collects it. For special callsigns, there are amateurs who collect by trying to make contact with an elusive call, confirm their contact and receive a QSL Card to decorate their shack with. In Australia, three times a year, on Australia Day, the 26th of January, on ANZAC Day, the 25th of April and on ITU Day, the 17th of May, a licensed amateur gets a special callsign to commemorate those special days in the calendar. Australia Day is the official national day of Australia, marking the anniversary of the 1788 arrival of the First Fleet of British ships at Port Jackson. ANZAC Day is the national day of remembrance in Australia and New Zealand that broadly commemorates all Australians and New Zealanders who served and died in all wars conflicts and peacekeeping operations. It's marked on the anniversary of the ANZAC landing at Gallipoli in 1915. ITU Day is the World Telecommunication and Information Society Day, commemorating the foundation of the International Telecommunications Union on the 17th of May, 1865. On each of these three dates, radio amateurs in Australia can replace their VK prefix with AX and use their special new callsign on-air to make contact anywhere around the world. So, for now, I'm Onno AX6FLAB

The reported death of Amateur Radio due to FT8 is an exaggeration

Jan 18, 2019 332


Foundations of Amateur Radio The reported death of Amateur Radio due to FT8 is an exaggeration In 2017 a new digital amateur mode called FT8 joined the ranks of inventions related to our hobby. Since then it's taken the amateur world by storm, filled the bands with contacts and attracted a strong following among radio amateurs across the planet. Making contacts with low solar cycle numbers has never been so easy. Together with that following comes a growing chorus of those who decry this addition, the filling of our air with useless noise and it's too easy, not real radio, there's no conversation, who cares about contacts, I want to rag-chew, anyone can do this and it's not right. Clearly some think of FT8 as the end of amateur radio as we know it. Recently I came across a list of other technologies that made amateur radio too easy and would cause the end of our hobby. Amplitude Modulation or AM, Semi-automatic CW Keys or Bugs, Vacuum Tubes, Single Sideband or SSB, Radio Teletype or RTTY, Repeaters, Electronic CW Keyers, Transistors, Electronic digital programmable computers, Antenna Rotators, Integrated Circuits, Digital Signal Processing, Microprocessors, the Internet, CW Decoding Software, Automatic Link Establishment or ALE, Packet Radio, DX Clusters, Pactor and PSK. Of course some of those make current amateurs just shake their head, or laugh out loud. Who could imagine that AM or SSB would cause the end of the hobby, given that they replaced spark-gap transmitters, which incidentally became prohibited in 1934. As we invent new things - the ARRL referred to FT8 as the Latest Bright Shiny Object in Amateur Radio Digital World - we learn more, have more, do more and expect more. In 1675 Isaac Newton said: If I have seen further it is by standing on the shoulders of Giants. Every invention builds on the ones that came before it and apart from the banning of the spark-gap transmitter, each of these newfangled baubles has made it into the mainstream of our community, to the point of being ubiquitous. Can you imagine an amateur radio without AM or SSB today? Using Clublog aggregate data as the source, with almost 30 years of records, in 2002, CW became more popular than Phone for logging contacts. This is on the back of Phone contacts reducing overall as a percentage of logs, against the increase of RTTY, PSK and other modes. In 2017 FT8 joined the fray and both Phone and CW logged contacts reduced markedly. Interestingly RTTY continues to be used though not at the levels seen at its prime between 2005 and 2010 or so. As an overall percentage of contacts, FT8 is by far the most popular. 2018 showed that over 40% of logged contacts were on FT8, CW remains essentially stable at 30% and Phone contacts account for 20% of overall contacts logged on Clublog. What this shows is that amateurs go where the contacts are. When CW worked better than Phone, it became the prominent mode. While CW use stayed the same, and Phone reduced, it was because contacts were being made with PSK and RTTY and other modes. This doesn't reflect the death of a hobby, far from it. It reflects the pragmatic nature of making contacts. You use a mode that's going to work. When amplifiers and big antennas were the name of the game, those were the tools being used by our community, but these days, FT8 has levelled the playing field for all comers. In a world where noise is ubiquitous and large antenna farms are possible for a select few, FT8 is making it possible for people to get on air and make some noise. No doubt some will decry that these are not real contacts and that exchanging a signal report isn't a real contact. Of course it is. It's just a different contact. Just like a CW contact isn't the same as an SSB contact and glorious AM isn't the same as FM, a contact with FT8 is like any other, it's real, between two stations using radio gear. I should point out that the logging information I looked at comes from Clublog and that in 1990...

Fan Vertical Antenna

Jan 11, 2019 265


Foundations of Amateur Radio One of the single most recurring topics within our community is that of antennas. Everywhere you look is a story or a photo or a website or a contact about an antenna that came into being because somebody had an idea. Now if you've been in the ideas field for a while you'll have learnt that having the idea is often just the start of the process. After that there's planning, sourcing, building and testing. If you're lucky you'll end up with something and a story to tell. If you manage to persist you might even end up with a working antenna. The other day I managed to have an idea that I'd not seen anywhere else. As it turns out and perhaps not unsurprisingly, I'm not the first to have this idea. Despite that, what struck me is that I'd not seen or heard of this combination of antennas before. As you might recall, one of my earlier forays into antennas consisted of purchasing a set of mono-band antennas. I intended to use these on my car while operating mobile, but despite countless unsuccessful attempts at making them work, the project ended up being abandoned and written up as a learning experience. That said, each of these antennas works just fine on a roof, just not on the roof of my car. Recently I'd been reading about how much separation is needed between antennas that are resonant on different HF bands and my research unearthed the idea that while they might affect each other to some degree the overall effect appears to be not that large. Combing that with an antenna called a fan dipole, I wondered if I could do the same with some vertical antennas. As it turns out, yes you can. It's sometimes referred to as a fan vertical. Before I get too carried away. A fan dipole is an antenna that consists of a set of dipoles that are all fed from the same feed point. Imagine three or four dipoles, each for a different band, with each centre connected to the same balun. Each of the legs are spaced apart so they're not touching. After a bit of tuning you'll end up with a combination antenna that works on each band. The beauty of this is that it takes up the same amount of space as the largest dipole and you'll only need one feed line, rather than several. You'll also only need two sky hooks, so you won't have to plant a forest before setting up your antenna farm. For all those reasons I wondered if I could make a single feed point for all my vertical antennas and get the same benefits. At one point I got so excited that I started modelling this in cocoaNEC, an antenna modelling tool based on NEC2, but my learning curve exceeded my skill set, so I had to postpone that in order to actually do some income generation instead. Discussion with fellow amateurs encouraged my tomfoolery, unearthed prior work and assured me that it would work and since then I've started down the procurement phase and have now got some SO239 connectors, a piece of metal and ideas to space holes evenly with a central socket to connect my coax to. I plan to solder all the connector centres together with some thick copper wire and use the metal plate to connect all the shields together. The only fly in the ointment at this point is my unhealthy relationship with drills. You might remember that I managed to drill a hole in my hand a while back - all healed, I was incredibly lucky, a delightful scar to remind me - so if at all possible I'd like to avoid such a thing. Last time all I wanted was to make a single hole bigger, this time I've got four 16mm holes to drill. You'll be pleased to learn, just as my partner was, that I'm now able to use a drill press and I even splurged and added a vice, so if I'm not too clumsy, I should be able to avoid stitches this time around. What I'm hoping to achieve is a little group of vertical antennas, connected to the same coax, mounted on the metal roof of the house, all but invisible to our neighbours without needing to swap antennas in and out like I currently do and actually use those...

Empirical evidence and the scientific method

Jan 5, 2019 258


Foundations of Amateur Radio Empirical evidence and the scientific method The hobby of amateur radio is a curious animal. It sits at the junction between empirical evidence and the scientific method. On the one hand it's all about physics, electricity, magnetism and the science behind those. On the other hand it's about trying something out and seeing what happens. When I started in this hobby, I was all about the science. I wanted to know "Why is it so?" "What evidence is there to support that?", all the typical questions you might ask if you're coming at this from that direction. As is often the case, the more you know, the less you know. That is, the more you understand a topic, the more you understand that you know nothing. The deeper you dig, the more variables become apparent, the deeper the hole goes, the further away from absolute you travel. That's not to say that our hobby is unknowable or non-deterministic, far from it. It's often so complex as to defy immediate explanation using high-school physics. You'll get to a certain point with that knowledge, then from one moment to the next you'll open a door into a world where that knowledge is just not enough. Interestingly when you look at for example the standard way of determining the length of a dipole, a fixed number divided by the frequency, that number we use, what ever the value, is an example of an empirical evidence based number and as observations go, it's not a particularly good one, which is why when you start using it you'll find all manner of exceptions, alterations, modifiers, etc. If there was a formula for a dipole, it would not just have that fixed number and the frequency. Nor would it be a simple division, since the number of variables is likely to head to infinity by the time you actually approach something that can model the real world. Between those two extremes, the quick-and-dirty empirical calculation and the intricate model at the scientific end lies a point of "good enough". The point of "good enough" is where what you're calculating is likely to end up with something that works most of the time. It's not 100% accurate, nor is it trivial, but it gives you a level of confidence that the thing you're calculating is useful and reproducible in many circumstances. I've been told by those who have told me that they know, that the fixed number divided by the frequency is on that "good enough" point, but my experience and the evidence says otherwise. Oh, that's ok, just add 5% to that number, or just cut it long, or insert some or other correction factor to account for the variation, that will give you "good enough". Ok, I'll bite. If that's "good enough", why are we teaching our new amateurs that this is how you create a dipole, no explanation about the variations, the effects of the environment, the material used, just: "Here's a number that you divide by the frequency and you'll have a dipole." My point is that it's time to revisit some of the things we think are "good enough" and look for something "better". I'm not advocating that we all need to become theoretical physicists, though for some that might be just the ticket, but I am saying that we should not just state that making a dipole, or calculating anything associated with our hobby, should be done without context. Here's some context for the magic number 468. Ward N0AX did the research almost a decade ago. It's a fascinating read, look it up! Turns out that the first occurrence of the magic of 468 comes in the form of 438. Yes, that's correct, 438 was the first attempt at making a magic number and it was based on measurements by G. William Lang in 1926 and it was based on averaging measurements for several antennas. In the 1929 ARRL handbook the number 468 first appeared and has been repeated ever since. Apparently as it turns out, the more you repeat something the more it's right. To the point of being ridiculed if you dare question the validity of such a notion. So,...

QRP EME project update #1

Dec 29, 2018 350


Foundations of Amateur Radio QRP EME project update #1 Over the past year and a half I've been working on a secret project. Today I'd like to share what I've been up to. To set the scene, I'm not doing this on my own, a fellow co-conspirator is Randall VK6WR who became an amateur about 20 months ago. Randall has a long association with the Engineering Development Array and the Murchison Wide Field Array, two of several radio telescopes that are built on one of the few radio quiet areas in the world and located near the future home of the Square Kilometre Array, the SKA. One day Randall and I started talking, as you do, new amateur, new topics, interesting new fields and ideas. We hit on the idea that radio astronomy telescopes are able to receive 2m signals. This started a discussion about using a radio telescope to receive a moon-bounce signal. So, the idea was born. Can we create a 5 Watt signal, bounce it off the moon and have it be heard by a radio telescope? Randall and I have been working on that on and off since our first discussion. Let me start by pointing out that we've not managed this yet, but we think it's a project worth doing, to forge cross skill exploration by various different groups. I have a strong background in IT and a few years as a radio amateur; Randall brings with him a wealth of radio astronomy engineering expertise, not to mention signal processing, communications and myriad other skills. We started to do this on the quiet, why talk about something that hasn't happened, might never happen, could be done by someone else who'd claim the glory before we did, and so-on. I've come to the realisation that while those things all hold true, this is a non-trivial project to achieve and anyone who puts in the work and gets there is welcome to claim the glory. So, in the 20 months gone by, while both working full time we've done lots of things. Let's set the parameters. When we first started, both of us were holders of an amateur foundation license. This means hand-keyed Morse, 10 Watts and band restrictions. Because I'm me, I decided that the difference between 10 Watt and 5 Watt wasn't significant enough to make or break this, so we went with 5 Watts QRP. Our license precludes the use of WSJT modes, invented by another radio astronomer, Joe K1JT, so the signal had to be something else. We settled on a manual slow Morse signal. We're using a radio telescope at one end, so it had to be on 144 MHz. Those decisions made, our first project was to attempt to calculate if we could actually achieve this. Conventional wisdom says no, but our ongoing calculations revised several times since our original effort, show that we're right at the edge of what is possible. We then started the process of determining if the radio telescope could actually hear moon bounce radio signals. We have a limited field of view, roughly 20 degrees around vertical, so the moon has to essentially be above the telescope. The galactic centre is a very noisy place from a radio perspective, so it has to be at least 20 degrees away from the moon. Similarly the sun, also very noisy, needs to be 20 degrees away from the moon. That started a process of me learning Python, so I could use Astropy to create a table with observation times that match those criteria. I'm still working on that. Having been a programmer for 35 or so years, I'm not a fan. We did some manual calculations to do some test runs and had two amateurs send a signal to the moon, which for several reasons, we were not able to detect. Traditional Earth Moon Earth, EME, communications benefit from ground gain, something like 3 to 5 dB of gain based on the path essentially ducting across the earth, but that requires the moon to be near the horizon, so not relevant for our project, since the moon needs to be overhead. Of course, it might mean that I need to travel half-way across the globe, so I can get the gain, but that's another project for another day. We get some...

What are you proud of?

Dec 22, 2018 262


Foundations of Amateur Radio Often we forget the things we've done or achieved and every now and then it seems like a solid use of time to reflect a little on what went before and what that did. Recently I asked various amateurs what they were proud of having done or achieved in the past year, their little personal victory, their thrill to keep coming back to the hobby. For me it was the research and production behind "Is man-made noise really vertical?". It took several weeks to research and produce and received only a handful of responses on social media or via email, even though it was downloaded and read about 10,000 times or so. For me it gives me a thrill to have spent time digging into the Who, What, Why, When, Where and How of a topic that seems steeped in myth and often remains unexplained or unexplored. One amateur shared that they'd made their first HF contact from Perth to Romania, one had gotten their license this year after procrastinating for 30 years, another came back to the hobby after being away for a decade. There was an amateur who managed to set-up a rotatable Yagi on 6m. There were a couple of amateurs who have each been building a repeater network, another who built a 6m Yagi antenna and pre-amplifier, another who erected their tower after 5 years, another who managed to get an article published in the national amateur radio magazine, another who set-up their G5RV and connected it to an Air Spy to make WSPR spots after only a year and a half in the hobby. One amateur got their license upgrade and is looking forward to learning CW next year, another got their station fully set-up and returned to being an active radio amateur. There was an amateur who managed to get through a 20m SSB pile-up. A friend told me that their achievement of the year was to listen, both to others and themselves. There was an amateur who used 10 Watts to make a contact between Massachusetts and New Zealand, one who worked the SO-50 satellite with a Baofeng radio and a rubber duck antenna. One amateur managed to work AO-92 with the same type of gear, made two contacts and even has a recording from one of them. One amateur celebrated the arrival of their Bengali key, considering it Christmas before Christmas. One amateur who made their first contact between Texas and the Netherlands used a 20m self-built Moxon beam constructed from wire and fishing poles. There was an amateur who got their license and is impatient to get on air, it's been a week of waiting. One person upgraded to the top license class and actually started operating. One aspiring amateur was inspired by how easy it was to get licensed and is planning for their entrance as a licensed ham in the new year, mind you, that did't stop him from listening and decoding a NOAA satellite image using an RTL dongle. One amateur decided that he just couldn't wait for his license, studied three days and passed his test. He's now building his first radio, looking forward to making a contact. There's an amateur who joined the ranks and is now looking forward to going for an upgrade to his license next year. One ham has been licensed for 10 months and is already having a blast, erected his first real tower and now has a VHF antenna at 60ft, that's 20m up in the air. There's one amateur who has been learning about what a cheap RTL-SDR dongle can do with SDR# and he's saving up for an Icom 7300. He's finding it tough to balance between spending his money on high-end audio and saving for his Icom. Take it from me, the radio wins, every time! I've only scratched the surface of the activities undertaken in the past 12 months, but it's clear that being an amateur is a positive experience for many people, getting on air and making noise, learning, having fun, trying things and exploring this wonderful hobby is ingrained in much of the community. Before wrapping up, I'd also like to credit Will VK6UU for independently asking the same question and for the countless amateurs...

Contest Headphones and glorious HF SSB

Dec 15, 2018 236


Foundations of Amateur Radio Recently I managed to get some quality on-air time when I participated in a contest. This isn't about contesting. Although I suppose tangentially it is. It was a most enjoyable experience shared with some friends and because we did it at a local radio club, Sunday morning had all manner of visitors joining us for a little social chat, just the ticket for breaking the monotony of calling CQ. Normally when I do a contest I wear headphones, actually it's a headset, that is something over my ears with an attached microphone to capture my contacts without me having to use my hands or move my head towards a fixed location while I'm making the contact. One hour in my trusty headset broke clean in half. They've been with me since 2012 so I was a little disappointed. They weren't cheap. I'm not going to tell you what brand it is, but they're very popular in the contesting community and I bought them based on those recommendations. Given that I now had no headset I immediately went to the nearest social media outlet to ask for recommendations on what to do next and the typical responses included different brands, ways of repairing, better models, those kinds of things. Everything you'd expect from a community which has some experience in creating a headset that actually works within the context of amateur radio. Don't get me wrong some of these suggestions were great but I don't particularly fancy spending $500 on a headset that is suited to listen to glorious HF SSB. If you're not familiar, think long distance AM radio playing music you can barely hear hosted by a DJ you can almost make out. Making a contact using HF SSB is really an exercise in deciphering really bad audio, often with lots of people on the same frequency at the same time, all vying for your attention. Making a contact, a QSO, in that kind of pile-up can be a challenge. The contest ran for 48 hours so in my down time I had to come up with a solution since making a repair within the time available seemed unrealistic, even though I happened to have spare parts somewhere in my shack. As an emergency standby I brought along my mobile phone in-ear headphones. They're lightweight, cheap, and they block out the audio from nearby conversations in the shack. Everything you want in a contesting headphone. I used a microphone on a boom, attached to the desk, but that wasn't ideal, moving your head, looking at the logging screen, operating the radio, from a user interface perspective, it left me wanting. I should add that I prefer to operate a contest using Voice Operated Control, or VOX, that is, setting up your radio in such a way that you don't need to push any buttons to talk, you open your mouth and the radio automatically starts transmitting. Very helpful when you have your hands on the keyboard and the foot-pedal is just out of reach or making your leg tired because you have to hold it up so you don't accidentally key up the transmitter. It occurred to me that I'd never seen this particular use of a headphone in the context of amateur radio. After the contest I went out to find a similarly spartan microphone. I'm still weighing up the options but I think I might have settled on the idea of pursuing headphones and microphones intended for use on a mobile phone, precisely because they are designed to deal with blocking out surrounding audio from both the earpiece and the microphone. As I'm describing this to you it occurs to me that it doesn't even need to be wired, a simple Bluetooth audio module plugged into the radio with wireless mobile phone headsets might just be the ticket. What has been your recipe for success in creating an environment where you can hear a HF SSB QSO in a contest environment without spending half the value of the radio? I'm Onno VK6FLAB

How do I get a better antenna?

Dec 8, 2018 210


Foundations of Amateur Radio The question that new amateurs most often ask after "What radio should I buy?" is "How do I get the best antenna?". In a household where you're the only antenna affected aficionado the question is likely more along the lines of: "Why do you need another antenna?". The answer is pretty much the same, an antenna is fit for purpose, generally only one purpose. Going from A to B without walking might involve a car. If it's just you, one seat is enough, if your local cricket team is coming too, you might need more seats. If the road is rough, you might need a good suspension and if it's the middle of summer in Australia, air-conditioning isn't a luxury but a necessity. Each of those different requirements varies depending on circumstance and need. There are plenty more variables, fuel, distance, cost, and the deeper you dig, the more choices. Antennas are no different. While cars have an element of fashion, colour, styling etc. antennas are more utilitarian, radio amateurs rarely care about the colour of their contraption, but they do care about cost, construction and performance. Those three variables alone would make for plenty of choice, but we've not yet talked about some other variables that come into play. If you're a licensed amateur, picking the frequency you want to use is obvious and a major factor in the choice of antenna, but if you're not an amateur, that's not something obvious, but you have seen it before. Without going into the physics of how and why, imagine all the antennas you've seen in your life. There's a TV antenna on the roof, the antenna on a transistor radio, an antenna on a car, the antenna on your Wi-Fi modem, a mobile phone antenna, satellite dishes, you might have seen antennas near train lines, on top of traffic lights, on a GPS and on a satellite phone. You might not be familiar with all of them, but enough to know that there is a huge range of different types of antennas. The more you look, the more variation you find. You might think that each of those different antennas was chosen at the whim of the person spending the money, but actually, each of those antennas was chosen for a specific job. Each of those antennas works on at least one frequency, sometimes more and does so taking into account its purpose. Is the antenna for sending, or receiving, or both? Is it supposed to work regardless of where it's installed, or how high off the ground it is? Does it need to take into account interference from a particular direction? Is it meant for strong or weak signals, does it need to have a defined lifespan, deal with a particular wind strength, etc. etc. Answering each of those questions determines the choices made to select an antenna from the infinite variety available. As an amateur, my licence allows me to operate in six different frequency ranges or bands. Technically that means at least six different antennas, just so I can use the frequencies I'm licensed for. Of course I'm only scratching the surface here, since I've already explained that antennas come in many different shapes and sizes, each with different characteristics and trade-offs. So next time you wonder why so many different antennas, that's why. If you've been wondering when I'll answer the bit about the best antenna, you should already have a clue by now, but the real answer is unsurprisingly: "That depends." "On what?" you ask. On which ever variables you care about and to which degree. The best antenna depends on the questions you ask. Ask better questions, get a better antenna. I'm Onno VK6FLAB

When does knowing more make it harder?

Dec 1, 2018 177


Foundations of Amateur Radio The other day one of my non amateur friends asked for some help. He wants to set up a receiver for his bush fire brigade that's available via the internet so his community can listen to the communication channels when there are fires around, or when a volunteer is out of radio range but still wants to hear what's going on. His question was about hooking up an antenna. We started to discuss what he already had and it turns out that he has enough coaxial cable in either 50 Ohm RG58 or alternatively 75 Ohm low loss quad shielded satellite TV coax. He's not an amateur, won't be broadcasting and just needs it to work without spending too much money. We then started talking about antennas and he had a tuned whip and a generic scanner antenna. Turns out that the tuned whip was for 78 MHz and he needs to listen to 164 MHz, so I suggested the scanner antenna, so called broadband, but no actual specifications. Then we talked about how it was going to be mounted to his metal roof. Tek screws to the iron, a CB mount with solder pads. That started a conversation about waterproofing and coax rot, termination and then the ground plane. I could get my antenna analyser out, drive to his place an hour or so away, help him install and test it and then decide that we need other options. We might still decide to do that, but it will be driven by what happens at his installation. If you're a licensed amateur with a little experience, this story will leave you with a whole lot of but, but, but. If you're not, then you'd come away with, that's pretty reasonable, let's go. What I find fascinating is the gap between those two. On the one hand you've got knowledge that says this isn't ideal, who in their right mind would hook up a random antenna without the proper ground plane with an unknown feed point impedance to a 75 Ohm coax, using solder pads on the top of a roof. There's more of course, but those are the big ticket items. On the other hand you have an antenna, coax, connectors that fit and a high likelihood of noise coming from your radio. I'm not going to pretend that the choices we made over the phone are the final ones, or that it will even work as described, but we discussed that and the selection of parts gives us the highest chance of success, and rather than give the right answer we went with the closest we could get without spending a cent. The gap between knowing and not knowing can be perilous, but it can also be used as a map to navigate from one to the other. Is this going to work? Who knows, too many variables to be certain, too many unknowns. Sometimes ignorance is bliss and sometimes knowledge is a burden. Finding the balance is a lifetime of learning. I'm Onno VK6FLAB

Are you an Elmer?

Nov 24, 2018 215


Foundations of Amateur Radio Are you an Elmer? In our hobby there is a term "Elmer", referring to someone who helps new amateurs find their way inside the community, locate resources, understand techniques, etc. It's part of what we might consider the folklore of amateur radio. I started this with the intent to quickly introduce the concept of an Elmer and then spend some time talking about our own role in this adventure, but as is often the case, I was side-tracked by my own investigation. There is a push within the community to abandon the concept of an Elmer, that it's not real that it serves no purpose and that it's a recent invention and irrelevant to our community. Finding an Elmer today appears to be hard work, seeing the wood for the trees, finding a unicorn in this social media connected world. But as it turns out, Elmers are closer than you think. With a little searching, the person who is credited with introducing the word Elmer into the amateur radio vocabulary was Rod W9BRD. He was the author of a column "How's DX?" in QST magazine from 1947 through to 1978. In March of 1971 he wrote: "[t]oo frequently one hears a sad story in this little nutshell: 'Oh, I almost got a ticket, too, but Elmer, W9XYZ, moved away and I kind of lost interest.' Sure, the guy could have burned through on his own, maybe, but he, like others, wound up an almost-ham. No more Elmer. We need those Elmers. All the Elmers, including the ham who took the most time and trouble to give you a push toward your license, are the birds who keep this great game young and fresh." Rod was first licensed in 1937 as a 14 year old. He became a silent key in 2012. On the face of it we have this idea that an Elmer is someone who helps you get your amateur license, but it started me thinking. What if Elmer wasn't a phrase, but a reference. The name Elmer is a male name from Old English, meaning "noble" and "famous". What if W9XYZ wasn't an actual callsign, but an example, given Rod was licensed as W9BRD, it would be simple to think of XYZ as a random suffix, much like I might use VK6XYZ, which happens to be a non-existent call at the moment. What if Rod was saying: Oh, I almost got a ticket too, but Peter VK6LB, or Paul VK5PAS or Mary VK4PZ, moved away and I kind of lost interest. Instead of using real amateurs like I just did, Rod wanted to use a generic name, someone "nobel" and "famous", with a generic callsign to not single out a particular person. The reference to "Elmer" takes on a whole different meaning. It means anyone, you, me, the amateur at your club, anyone who can help another person become an amateur. As it turns out, "Elmer" is all of us, it's a way to refer to anyone and everyone, it's not a specific role or purpose, it's the invitation to you to help another amateur. This of course means that you need to step-up. You don't need to put on your Elmer cape and become a superhero, you just need to be part of the community, to ask questions, to help with discovering answers and to encourage investigation into this exciting pursuit of amateur radio. So, are you an Elmer and if not, what are you going to do about it? I'm Onno VK6FLAB

When failure doesn't matter ...

Nov 17, 2018 219


Foundations of Amateur Radio The other day I read a message from Theodore KS5I who has been around the block a couple of times. He recalls the excitement he experienced when he was first licensed in 1967, the year I was born. He described that at the time transistors were just coming into their own and it was so wonderful to be learning about them. The closing sentence sealed it for me: Theodore wrote: Perhaps, its time for some of us more mature operators to release the past so our hands are free to grab hold of the future and share the enthusiasm of those who look ahead with the same hope and excitement that we had so many years ago.. It's that level of enthusiasm that our hobby needs to foster and develop. The landscape we live in is changing all the time, but new adventures are always just around the corner. They might not look like what was available 50 years ago, or last year, or even yesterday, but they too have their place in the pursuit of amateur radio. Learning is a lifelong activity. If you stop learning, you - as Theodore eloquently puts it - just die. Learning can be scary. Educator Eduardo Briceño talks about the learning zone and the performance zone. The learning zone is when the goal is to improve, concentrating on what we've not yet mastered and the expectation is that mistakes will happen. The performance zone on the other hand is when we do something as best as we can. We concentrate on what we already know and try to minimise mistakes. Amateur radio can operate in either of those zones, doing a contest and going hard can be a performance zone activity, do what we do, do it fast and avoid mistakes. We could also see our activities as a learning zone. We try new things, some will work and some will fail. If we're doing a contest as a learning activity, what skill do you want to master? Is it handing off the QSO, taking the log, recognising a callsign, knowing the CQ zones, matching prefixes to countries and antenna directions, picking the right band, managing battery life or recognising the band conditions? Pick one of those skills and try different things, expect mistakes and learn from them. Over time the thing you practised will be a new skill you've mastered, ready for use when you're going hell for leather in the CQ WW making contacts left right and centre to the envy of your peers. Of course, this doesn't just apply to contesting. For me it's currently about electronics, about figuring out how stuff works and how to apply that to my shack. For you it might be something else in the myriad of options that the 1000 hobbies that amateur radio represents. Life is about growing. Amateur radio is a journey, not a destination. Closing off your options because valves are no longer in vogue and Allstar isn't real radio is just a recipe for stagnation. If you have a dozen minutes to spare, check out Eduardo Briceño's TED talk: How to get better at the things you care about One final point. If you're new to this adventure, your license still wet, then you don't know what you don't know, so you'll spend lots of time in the learning zone. Don't be afraid, it's a great place to be and a wonderful way to explore the hobby in all its variety. I'm Onno VK6FLAB

The Golden Age of Amateur Radio is Now

Nov 10, 2018 209


Foundations of Amateur Radio The Golden Age of Amateur Radio is Now Imagine a world where electronics are pervasive, a transceiver can be purchased for the price of two Big Macs, kits are designed and built using simple tools at home, software makes it possible to invent new methods of communication on an almost daily basis, where long distance contacts are made throughout the day using milliwatts while ionospheric propagation is at an all-time low, where national parks and peaks are being activated at an increasing rate, where new people join in every day, where it's easier and easier to obtain a license and where the word geek is held as a badge of honour. That world is here, it's now and when Rex, KE6MT writes that we're in the midst of a golden age of amateur radio, he hits the nail on the head, or should that be fist on the key? It's easy to notice that amateur radio is difficult, that it's big, that it's messy, that it's full of know-it-alls, but it's hard to remember that it's fun, that it's rewarding and that every day more and more people join in and enjoy this hobby. The ideals of investigation and exploration are alive and well and the urge to participate in activities, just to get out of the house and see some daylight is strong. While you're in the midst of a revolution, it's hard to see the wood for the trees, but make no mistake, the revolution is here, today, now, and you're smack bang in the middle of it. Today you can go online and find any number of different amateurs who share their skills and knowledge, you can find manufacturers and suppliers at the tap of a screen, find and draw schematics, order custom circuit boards at the click of a check-out button, print an enclosure in your bedroom using plans that you downloaded or designed minutes before. With the digitisation of amateur radio comes the promise of new adventures, with adaptive modes, with encoding and decoding in new and interesting ways, with the ability to hear what your station is producing by logging into a remote receiver anywhere on the planet, by sending messages to satellites overhead and talking to people in another country using a hand-held VHF radio. For some the loss of the valve radio is the loss of history, for others it's a sign of progress and improvement. The inventors of spark-gap transmitters were no doubt put out by the arrival of the valve when that became commonplace. Similarly, the transistor has essentially gone the way of the Dodo in the arrival of cheaply programmable integrated circuits. Our hobby keeps getting bigger, all the time. We didn't abandon valves or transistors, or the spark-gap for that matter, we improved on them. You can still build a spark-gap transmitter if you feel the urge, or ferret out a valve or two and build them into something wonderful, nobody is stopping you. Today we learn Morse Code because we want to, not because we have to. We introduce new people with new technology, new ideas, new innovations and hope that they pick up the cape to become the next superhero. You can bemoan the death of the hobby with the solar cycle at an all time low, the entry of stupid amateurs who need to learn from their betters, the passing of the valve and the abolition of Morse Code requirements, or you can celebrate the appearance of all the new and shiny toys that arrive in our hobby every day. The Golden Age of Amateur Radio is Now. I'm Onno VK6FLAB

Everything you wanted to know about amateur radio but were afraid to ask!

Nov 3, 2018 225


Foundations of Amateur Radio There are people who ask questions and there are people who answer them. Sometimes the people who answer even know what they're talking about, but sometimes they just repeat what they've been told without any form of critical thought. The reason I raise this is because when you're a new amateur with a shiny new license, you're like a little puppydog, going from tree to tree to have a sniff. Does this smell good, what about this, ooh, that's a nice smell, I wonder what it tastes like. Puppydog analogies aside, as a new amateur you're filled with questions and uncertainty. You don't know what you don't know, you don't know how much you don't know, your license is still wet, so even if you know something, it might not be true. Interestingly the more I look at this, the more I find that new amateurs, filled with questions are more likely to dig around in the fundamental understanding of things and learn something along the way. I've been around this community for a little while now. I obtained my license in 2010. I've learnt a lot of different things about this hobby, how it works, what the mechanisms, phenomenon, etiquette, physics and so-on make amateur radio work. Most of the time I'm learning about some or other new thing. Right now I'm learning about what a Vector Network Analyser is and how it works, so I can explain it to someone else. Foundations of Amateur Radio is about how stuff works, much like Joe Kaufman's book - What makes it go? Though I read it in Dutch when I was growing up - Hoe zit dat in elkaar? There's another series of books by David Macaulay that are my inspiration, The Way Things Work, Unbuilding, Underground and Motel of The Mysteries to name a few. It seems that my drive to ask questions is fundamental to my existence, my uncertainty doesn't scare me off, in fact the opposite is true, it gets me asking more questions, learning more things, gaining a deeper understanding and finding out more than I ever dreamt was possible. If you're a new amateur, I'd recommend that you attempt to keep your curiosity alive. When you're faced with a fact, question it, attempt to discover what is underlying the response. There are amateurs who think that to ask the question, Why is the length of a dipole calculated using some random constant? - is the equivalent of heresy, lack of skill, incompetence and the source of much derision, when it's clear that even a cursory search reveals that not only is the notion incomplete, it's wrong for most, if not all, examples. My perspective is a little different and I'll admit that for some it might be confronting. Why is it so?, What makes it go?, How come? and Why? are all questions to live by. You might conclude that a world where there are no certain answers is a scary place, but for my money the opposite is true. Just because you think it's simple and answerable, doesn't make it so. If you walk in with your eyes open asking questions, then you'll be much more prepared for an unexpected response. If you've just obtained your license and you're not sure about something, ask. You might not like or understand the answers, but that is just a recipe for more questions. Don't be deterred by those who provide certainty, the more certain they are of their answer, the more you should ask. Amateur Radio is about experimentation, it's a license to play, a license to explore, it's a license to investigate. For me Amateur Radio is encapsulated in a quote attributed to Albert Einstein: The more I learn, the more I realise how much I don't know. I'm Onno VK6FLAB

Get on air and make some noise ...

Oct 27, 2018 312


Foundations of Amateur Radio Get on air and make some noise is a phrase I use often to encourage amateurs to be active on-air and use the bands that are available to us. One thing that's often glossed over is how to actually make that noise. It can be scary to make that first contact. If you've got your radio installed, your antenna erected, your operating position set-up just right and you're ready to actually key your microphone, how do you do that and how do you get the attention of those around you? First things first. You need to establish if your radio is actually working as expected. If you're using a UHF or VHF radio, often the simplest way is to find a local repeater, key-up your radio and give your callsign. The result should be at least a carrier, a beep or a callsign in Morse-code. Some repeaters even have a voice ident, so you can hear that your action of keying the push-to-talk had an effect. If that isn't working, then there are lots of things you can troubleshoot, but that's for another day. If you want to do the same on HF, unless you happen to be in a position that there is a repeater within propagation distance, generally only on the 6m and 10m bands, then you're essentially out of luck. There isn't a beep, or a carrier, or a voice-ident to be found. This means we have to solve the problem in a different way. First of all, if you cannot hear any stations, the chances of someone hearing you are slim. So, the first thing to do is to check that the squelch on your radio is set to allow all signals to arrive at your speaker. Then find a band where it's noisy. When I say noisy, find one where there is lots of hiss. Generally speaking an open band, one where propagation is getting a signal to you, makes noise, lots of noise. There are exceptions to this, but for now, find the noise. Depending on how you have your antenna set-up, you need to make sure that you're using the right antenna for the band you're using. Some antennas work on multiple bands, others only on one, it depends entirely on what you have got hanging off the end of your radio. Once you've found the noisiest band, go hunting for beeps, as-in Morse-code beeps, or voices, or digital sounds. Find a signal, find evidence of activity. If you have multiple noisy bands, check them all. You might recall that this is all dependent on the ionosphere, so depending on what's going on with the sun, things will change, sometimes within a minute, an hour, or weeks. Generally there is a difference between day and night and sunrise and sunset, so experiment. Once you've found some activity, you need to find someone to talk to. If the voice you hear is weak, look for a strong one. The stronger the better. While this isn't universally true, it's a good starting experience. Every radio and antenna combination has a sweet spot on where you know that they can hear you, but you don't know yet what that sweet spot is, so trial and error is the way to go. HF is not like the local repeater. The people on HF can be anywhere on the planet. They might be there for the first time, or for the third time that day having been on air for sixty years, it's hard to tell. A good analogy is to think of a sport stadium with a hundred thousand people in it. There are people all around you and you're trying to make contact with one of them. You can pick their frequency, but they're likely to be talking to someone else. You might be interrupting a daily chat, a regular net, or happen upon a contest or a special event station. You don't know which one it is and sometimes you can't hear both sides of the conversation. So, before you key your microphone and make some noise, listen to what is going on. Once you've figured out that the station you're hearing might be amenable to talking, wait for a break in the conversation, key your microphone and just say your callsign phonetically, once. If there's no break, that's a good indication that the other station doesn't want to talk...

Celebrate accomplishments

Oct 20, 2018 220


Foundations of Amateur Radio Mistakes are common in all aspects of life. Sometimes they are only known to you, other times they are public knowledge and open to ridicule and lambasting. Getting on air for the first time is an accomplishment and often the initial source of mistakes, mishaps and great frustration. Once you've made it on air, the reception to this feat is often underwhelming, people around you don't appear to appreciate the amount of effort you went to in order to key your microphone and for others to be able to hear that. If you've been in this community for a while it's easy to forget what is involved to make that first contact and to dismiss those around you who've managed to obtain their license, acquire their equipment, install and configure it just so and to actually achieve the first visible milestone in their amateur radio journey, though technically it's audible. If you've never done this, or if you have but have delegated it to the historical backwaters of your mind, here's an outline of some steps and mistakes along the path of making your first contact. The first question you're likely to ask is, which radio followed quickly by, from where? Then, if you're like me and many other starting amateurs, you'll have set up your radio for operation on the local 2m or 70cm repeater, you're likely to have some kind of vertical antenna with the microphone gain and squelch set just so and have your radio set for FM. I'm skipping over power, the electrical type, but that in itself can be a feat of endurance. After hunting around for a list of relevant frequencies, you might also have set up something like CTCSS to ensure that your signal actually gets acknowledged by the repeater. If that's not enough, you'll also have made your radio use an offset which makes it receive using one frequency and transmit using another. There's possibly more things you've had to do to make this work and not be subjected to the ire of the local repeater troll who appears to delight in telling you off when they feel you've done something wrong, like leave the roger beep activated or some other infraction. If you did manage to achieve all these things and actually made your first contact on the repeater, congratulations and welcome to the hobby! Take a breath, you did well. After a while you're likely to become more familiar with your radio and start exploring the local bands. You might program another repeater into your radio and even experiment with local simplex frequencies. Each of these activities brings a new experience and new mistakes. For example, not all repeaters use the same offset, or even an offset in the same direction. Not all repeaters have the same CTCSS requirements. If you're using a simplex frequency, remember to turn off the squelch - don't ask me how I know - so you have a chance to actually hear the other stations, even if you are using FM as the mode. The process of getting on air as a first time user can be daunting, with many different points of failure along the way. Ignore the trolls, try your best and ask for help if you get stuck and celebrate your accomplishment when you manage to make a contact. My point is that achieving all this isn't trivial and it would be helpful if that's remembered from time to time. It's easy to dismiss an achievement made by another, but much more rewarding to celebrate it. I'm Onno VK6FLAB

Everything you know about dipole (calculators) is wrong ...

Oct 13, 2018 223


Foundations of Amateur Radio Everything you know about dipole (calculators) is wrong ... The other day I did an experiment. I searched for "dipole calculator" and using the first 20 results I calculated the length of a dipole suitable for 7.130 MHz. I chose the frequency for no other reason that there is a 7130 DX net every Monday, Wednesday and Friday and for the longest time I've been unable to participate due to the lack of a HF antenna in my new shack. So here's some things I learnt from doing this experiment. Depending on which calculator I use, the length of my dipole can vary by over a meter from longest to shortest result. Depending on my desire to use metric or imperial measurements, my dipole will be a different length, because of course electrons move at a different speed if you're not using the metric system. In case you're wondering, 1 inch is defined as being exactly 2.54 cm, so there's plenty of opportunity to vary that. Speaking of standards, we all agree that the speed of light is a constant, right? Turns out that for some calculators, you can change the speed of light. I'll skip over the notion that none of the calculators actually show what they're using as the speed of light and move on to other interesting discoveries. Apparently you can determine the length of a dipole down to the sub-atomic length, with one calculator going down to the size of an electron to indicate how much wire you should cut from a spool. There are forms that make doing the calculation really easy, single box to type in the frequency, so the answer must be right. There are some that use random standard numbers, even a text book example that uses some number, but no indication where it comes from. For example, the number 486 features regularly, but so does 150 and 5905. There are forms that provide you with several boxes, but no indication which box needs what value, so your answer may or may not indicate the number of eggs per chicken per parsec. One dipole calculator result is actually for a vertical, so your search engine helping you might not actually give you the calculator you expect. There are percentage correction factors. 5% seems to be a favourite number, but no indication as to what the origin of that number is. There's a calculator that allows you to specify the feed point impedance, not sure how that works, but it's a nice feature to have when you're calculating the length of your dipole. Not. One regular instruction is to cut long, that is, measure your wire and cut it longer than the calculator states. How much longer is left as an exercise to the reader. Should it be 1 mm longer, 1 cm longer, or should it be 1 m longer and how much should that change if the frequency changes? Let's move on. The word ground features heavily in these calculators. The phrase "average ground" does too. No indication as to what makes an average ground, or how to go about determining what changes if your ground isn't average. We all agree that the dipole should be half a wave-length above the ground, right? How much is that? The same wave length as the length of the dipole we've just calculated, or a different one? How does the length of the dipole vary if the height varies? While we're looking at variation, how much variation is there depending on how thick the wire you're using is and what about insulation? None of those things are even mentioned in any of these calculators. Dipole calculators, wonderful invention, shame about the implementation. I'm Onno VK6FLAB

Random bits of wire ...

Oct 6, 2018 226


Foundations of Amateur Radio One topic that is longer than all other topics combined is that of antennas. Designing, planning, sourcing, building, tuning, using, you name it, all of this is regular fare in the day of a radio amateur. I've discussed the topic here regularly and no doubt I'll revisit that when the mood or necessity takes me. One topic that is rarely discussed is that of failure. About six months ago I moved house. I've been rebuilding my shack, doing all manner of fancy shuffling of gear and yesterday I finally got to the point of getting some HF activity happening. During that process I went through boxes and boxes of stuff, with coax, connectors, wire, nuts, bolts, heat shrink and all the other necessities of being a member of an experimental hobby like ours. One box contained wire. You know the adage, only two types of wire required in our hobby, cheap wire or free wire with a preference for free. This box was stuffed with wire. Bits with connectors, bits wound around spools, bits in zip-loc bags with labels, bits of random length - lots of bits of random length. There was even an abortive attempt at labelling dipoles for various bands on the outside of a couple of zip-loc bags, but no idea if the bit of wire in the bag was actually ever tested and resonant on whatever band was on the label, so who knows, they might have just been cut long waiting for another day and another set of experiments and measurements. I needed around 50 meters of hook-up wire for my HF antenna experiment and it occurred to me when I was hunting through my box that I couldn't look at a spool and tell you how much wire there was. I did a dodgy measurement of one bit, put it on the kitchen scales and determined that another spool was heavier, so it was likely longer, but without bringing in my calculator, doing extra measurements and doing some head scratching there was no way that I was going to get to the point of knowing how much actual wire was on that spool. In the end I made do with the dodgy piece, soldered some joins, that's a whole other adventure, involving a gas-powered soldering iron and a flame, the flame won, as well as several other breaks and fixes. While I was in the process of putting up my new antenna experiment it occurred to me that part of the process of experimentation, even of shack maintenance should be the documentation stage. I have bits of terminated coax, some of it 20 meters long, some longer, some shorter. How much longer, and how much shorter you ask? No idea. But wouldn't it be great if I could put my hands on a piece of kit that I needed that was the length that I expected and not 10 meters over length, or 1 meter short. In my audio kit, I have started labelling patch leads with their functions, using key-ring tags. I don't expect that to work for plain wire, but it should be a good solution for coax. I could use cable tie labels, but past experience with those leaves the text fading on the label. I've experimented with a printed label with clear heat shrink, but for reasons best known to chemists, the clear heat shrink becomes yellow in short order leaving the label unreadable. I've heard of people using electrical tape with colour coding, perhaps one ring for every 5 meters of length, but they seem to come undone in the dust when you go camping. One thing I do know is that this is a recurring problem for me. This is the first time I've actually stopped to talk about it and perhaps it means that I'll get a little closer to a solution. I'd love to hear what you do to deal with this and how you keep track of the countless different lengths of wire, coax and rope that's lying around your shack. I'm Onno VK6FLAB

Is man-made noise really vertical?

Sep 29, 2018 301


Foundations of Amateur Radio One of the often repeated attributes of noise and antennas is that man-made noise is vertically polarised and that is why a vertical antenna sounds noisier than a horizontal dipole. It's an interesting thing to say, but it it true? Let's start with what constitutes man-made noise. Cars driving past, solar panel inverters, pool pumps, high-tension power lines, garage door openers, broadband internet modems, LED lights, lawn mowers, leaf blowers, plasma televisions and so on. The more you think about this, the more noise makers you discover. So, are these noise sources all aligned in the same way, making the same noise? Clearly not. There is no alignment standard for installing a lamp, how to align your lawn mower, which direction to drive, what angle to point your garage door opener, so the statement that man-made noise is vertical is clearly bogus. That doesn't mean that the rest of the statement is also wrong. A vertical antenna in an urban environment often sounds much noisier than a horizontal one, sometimes by several dB. So what's going on? One suggestion is that the difference lies in the antenna itself. What if both noise sources, horizontal and vertically polarised were the same, but the antenna heard them differently, how would that look? For starters, a horizontal dipole has a higher sensitivity at a higher angle than a vertical antenna does. So anything arriving at a low angle is picked up by the vertical, but not by the horizontal dipole. The noise that we're talking about is local, we'll get to why in just a moment. Being local, it gets to the antenna via ground wave propagation rather than via the ionosphere. I claimed that the man-made noise we're discussing is local. It's not all local, but if it's remote, it's coming via the ionosphere and we know that it arrives at whatever angle it pleases, so there is little or no difference between a vertical and a horizontal dipole from a noise perspective for signals arriving via the ionosphere. There is another effect. Attenuation or signal loss. In this case loss of strength. Specifically noise strength. More attenuation is the same as more signal loss. Combining ground wave propagation and attenuation brings us to another difference between a horizontal and a vertically polarised noise source. A horizontally polarised ground wave experiences more attenuation than a vertical one. This means that noise that is local travels further and is louder when it's vertical, compared to when it's horizontal, sometimes the difference is over 20 dB. I've been talking about horizontal and vertically polarised noise, but what if the noise is coming at an angle, like the random noise makers around you? A simple way to think of it is that every angle has a horizontal and a vertical part, in much the same way as a right-angle triangle has three sides, one horizontal, one vertical and one on an angle. Putting this all together, we have a number of different effects, all conspiring to make the vertically polarised part of noise travel further, be louder and received better by a vertical antenna, compared to the horizontally polarised part which doesn't travel as far, is softer and heard less by a horizontal dipole. One more thing. The isolation between vertical and horizontal polarisation can be as much as 40 dB, so a horizontal dipole won't hear vertically polarised signals well if at all and vice versa. That doesn't make the vertical antenna useless, far from it. It's great for transmitting a long distance signal, it's small, simple to set-up and if you're in a quiet area, away from noise makers, around 500m to a kilometre or so, it's just fine as an antenna. It also doesn't need to be erected half a wavelength above the ground, doesn't need any sky-hooks, is omni-directional and in common use for most local mobile communications, so don't write off the vertical, just because it sounds noisier. All antennas are a compromise between various...

Antenna Polarisation and you

Sep 22, 2018 252


Foundations of Amateur Radio The first time I came across the concept of antenna polarisation was a decade before I became a radio amateur. To connect to the internet while driving around Australia I became the proud owner of a portable satellite dish. Portable in the broadest sense of the word, 150 kilos with a dish that's 2.4m high, 1.8m wide, steel base, electronics, power and patience to erect and point. The dish has a receiver and transmitter component that needs to be aligned, just so, in order to be able to have two-way communications using 5 Watts into geosynchronous orbit. The transmit and the receive are exactly 90 degrees offset from each other. One is called horizontal polarisation, the other vertical. The first thing to observe is that if you're using the wrong polarisation, it doesn't really work well. We'll get into what is right in a moment. Depending on where you you ask, the definition of not working well can be as bad as 40 dB loss. Just let that sink in for a moment. If you want to punch through with more power, you'll need to bring 10 kilowatt with you for the receiving station with the opposite polarisation to hear 1 Watt. If you're using a VHF or UHF FM radio in your car, you're likely to have a vertical antenna. The combination of a repeater on a hill and a radio in a car adds up to much more than the the two alone. The line is blurred today because repeaters are very popular and home-base stations are becoming smaller and smaller by the week, so vertical antennas for VHF and UHF at home are today just as common as they are on cars. It wasn't always that way. In fact, in HF, it's almost never that way and if you're a fan of Tropospheric Ducting or long distance VHF, then you'll also shy away from vertical antennas. Let me explain. If you want to erect a HF antenna and you want it to rotate and you want it to be high enough off the ground, you'll build the simplest mast you can get away with. Imagine a HF Yagi. It's got several elements, long to short along a boom, rotator somewhere in the middle. If you mount this Yagi horizontally, your mast will be around half a wave length in height. If you mount the same Yagi vertically, aside from the height discussion - should it be mounted higher or not - now your mast becomes another interfering element within your Yagi. The steel wires that keep your mast standing will also interfere with the Yagi elements and your elements will be closer to the ground where they can potentially cause harmful radiation. So from a mechanical perspective, putting a Yagi on a mast vertically is not trivial. From a radiation perspective you may theoretically get some gain, but adding an element or two will make up for any potential gain that a vertical arrangement interacting with Earth might assist with. There's another reason. The ionosphere. It sounds like a smooth billiard ball, it's drawn as a uniform layer around the earth, but in reality, clouds and their appearance are much more likely to represent the actual surface shapes that the ionosphere presents to your radio waves. A signal coming in one way is unlikely to come out at the other end in the same way and vice versa. That's HF. On VHF and UHF a horizontal signal and a vertical signal when they're used with line of sight are pretty similar, but once you get beyond that, a horizontal signal will travel further, how exactly is a story for another day. If you're doing point to point VHF or UHF contesting, horizontal is the way to go. What about a single HF vertical? It's excellent for a portable station, it is simple to set up, works in all directions, but it means you'll be able to hear all the local man-made noise as well, so find a quiet spot near the beach if you can. So what's the right way? Almost always horizontal, except on cars or when you're on a DXpedition on a beach sipping pina collada and getting caught in the rain. I'm Onno VK6FLAB

Cloud Warming in style or what is NVIS?

Sep 15, 2018 222


Foundations of Amateur Radio The term NVIS, or Near Vertical Incidence Skywave is in my short experience as an amateur heaped with scorn and ridicule. Terms like cloud-warmer come to mind when people discuss the principles associated with NVIS, but that does happen in the context of where I live, that is, one of the most isolated cities on the planet, Perth in Western Australia. NVIS has several advantages over other forms of HF communication, it can be done with low power, there is little or no signal fading, simple antennas work well, it has low path loss, better signal to noise ratios and if you're in a valley, you can still use it. So what exactly is NVIS? In the past I've talked about long distance HF communication. Your radio signal bounces off the ionosphere, bounces back to earth and so-on. Like skipping a stone on a pond, the angle at which your signal hits the ionosphere determines what happens next. In general, shallow is good, steep is bad, much like the plop you hear when you don't hit the pond just right, a radio signal can go through the ionosphere, never to be heard again. NVIS is about hitting the ionosphere at a steep angle, in such a way that it reflects back to earth. Without going into detail, generally you can use 40m during the day and 80m at night with some variation depending on the solar cycle and whom you want to talk to. NVIS gives you communications less than 1000 km away, plenty to talk to everyone in your city and surrounding area. In the case of an emergency that's also likely enough to get out of any emergency affected area, so plenty of excuses to set up and try for yourself. I can start talking about angles, maximum usable frequencies and so-on, but I won't. These all relate to specific circumstances, depend on what antenna you're using, what the ground conductivity below you is and as is typical in our hobby, many other variables. What I can say is that NVIS to NVIS station works best, so if you're going to test this with a friend, it will help if you both set up a similar station while you learn the variation associated with this kind of communications. Now I did mention up to 1000 km, that isn't enough to leave Western Australia, Perth to the border is about 1500 km, but if you live in the Netherlands, you can get to 15 or so countries. Depending on where you are, NVIS will give you different outcomes and what I'm talking about affects each station differently. For me, the attraction of NVIS is solid communications on 40m and 80m, something that has eluded me so far. It also allows for a low simple wire antenna, an inverted vee dipole, two bits of wire strung up on a pole, 6m in the middle 2.5m at the end will get me up and running. Perfect for a field-day, excellent for a local contest and brilliant if you're only using low power as a beginner. Because the antenna is close to the ground, it's pretty much omni-directional. If you set-up an antenna for 40m and then cross that with an 80m antenna and feed them both from the same point, you'll have a configuration that will operate well for 24 hours without needing to move antennas in the dark. I have no illusions that an NVIS antenna will help me make contact between Perth and Japan, but then it's not intended for that. I've spoken in the past about finding the right tool for the job. NVIS is a tool, it has a job and it's very good at doing that. It's not for everyone, all the time, but it's a tool that you as an ambitious amateur should know about. I'm Onno VK6FLAB

How can I talk to my friend?

Sep 8, 2018 213


Foundations of Amateur Radio A recurring question for people who are not yet, or newly licensed is something along the lines of: I have a friend who is 400 kilometres away, can I talk to them on my hand-held 2m radio? This particular question arrives in different forms, but generally along the lines of attempting to communicate between point A and point B at some or other distance. The responses, on social media at least, less so on-air, are often very technical, or offer the advice to get a license, or to get a clue, or the question is ignored or dismissed. That's not helpful, or fair. The person asking the question has expressed an interest in our hobby and is looking for help. As a basic set of answers, if you're both standing on the ground, you'll generally be able to talk about 5km using your hand-held. Stuff between you like buildings and hills will lower that distance. If you both stand on a hill, you can talk further away. As an aside, you can talk to the International Space Station with a 2m, 144 MHz hand-held because there is nothing between you and it when it's overhead, even though it's 350 km away. If you cannot see between the two, then an intermediate radio, a repeater, can facilitate the connection. It needs to have visibility to both radios at the same time. The higher the middle point, the further the distance. For example an antenna at 350m above the ground has a so-called radio horizon of 77km and I should point out that that's actually 15% further than actual line of sight. As long as both ends are within that radius, you should be pretty much good to go. You can theoretically string together a whole bunch of repeaters, along a road for example, but more often than not, for distances greater than line of sight you need to invoke radio frequencies that your 2m hand-held won't do. These frequencies are generally referred to as HF and is generally anything between 3 and 30 MHz. Radio transmissions on these frequencies mainly use the ionosphere to make contact possible and you can make contacts from as close as next-door, to as far as the opposite side of the world. The ionosphere is subject to weather in much the same way as clouds and rain. The variation in the ionosphere is driven by the sun, not by wind and humidity, and it varies throughout the day as the sun rises and sets. Communication varies depending on where the sun is and several other factors well outside this explanation. As the ionosphere changes, usable frequencies change. Something that worked one moment might not the next because the ionosphere changed. As a licensed radio amateur you have access to many different frequencies and depending on the state of the ionosphere you can change frequency as required to alter your station to suit the conditions. You can think of it as adjusting your sail depending on the wind direction, to get from A to B. One final point. Antennas are many and varied. They are designed for specific purpose and will react differently depending on how they're designed, built, installed and used, so the variation you're stepping into is enormous. This hobby is nothing like dialling a phone number and making a connection, it's all about the experience and the learning. If that tickles your fancy, you're already halfway to becoming an amateur. Welcome. I'm Onno VK6FLAB

Nothing like the standard of Morse Code ...

Sep 1, 2018 406


Foundations of Amateur Radio Nothing like the standard of Morse Code ... Morse Code is a way of communicating with people across the globe using dits and dahs and the spaces between them to convey a message. It's no longer required to get an Amateur License, but that doesn't mean that it's not useful, in fact, far from it, Morse is still heavily used in this hobby. I've been attempting to learn Morse code for quite some time. To do this I was told, time and time again, over and over, ad nauseam, that Morse is an Auditory Language. I was told that the way to success was to listen before sending, to be able to decode before ever touching a key and to learn with tapes. I also was told that if I learned it slowly, I'd run into trouble later on when I wanted to hear a beacon, which identifies itself with much faster Morse Code. Morse is an interesting phenomenon. We describe it in words in day-to-day terminology as having dots and dashes, which is how the International Telecommunications Union, the ITU defines it, but I have been assured that I should think of it in terms of dits and dahs, because that more closely mimics the sound of the language, and from my current experience, I have to agree. This is an audio language and it's defined in terms of how long a dit takes to transmit. A dit is one time unit. A dah is three dits. The space between a dit and a dah within one letter is one dit. The space between two letters is three dits and the space between two words is seven dits. I'm not expecting you to learn that right here and now, just pointing out that there is a definition of how this is supposed to work. If you make a dit last longer, everything else lasts longer, so determining how fast you're sending something is not simple to do, unless there's a standard. Of course there's a standard. The way that the speed in Morse is defined, is by counting how many times a standard word can be sent per minute. The Paris standard uses the word PARIS, because it is precisely 50 dits in terms of timing. There's another word, CODEX, which has 60 dits, so the two Words Per Minute are different depending on which standard you use. And to make things even more interesting, some people measure with 5 dits between words where the ITU specifies 7 dits between words. So, speed is variable, depending on who's measuring. The ITU doesn't specify which is right, but it gets better. As I said, this is an audio language, so you need to listen to it to learn it. Over the years it's been hammered into me, don't write Morse, don't use dits and dahs, listen, listen, listen. I did. At 25 Words per Minute, at what ever standard that was calculated, I can now hear Morse, that is, I can detect the gaps between letters and words and I can hear the rhythm of the code. Great, so I'm done, right? Not so fast. While I can hear the individual letters, I still don't actually know what a G sounds like, or what makes the letter X, or an Open Parenthesis, or a Question Mark. Easy, look them up, learn the sound, done. Morse Code is standard, right? Right? Seriously, Morse Code is standard, right? No. Not so much, not even a little bit. If you search the globe for Morse Code Charts so you can look up a Question Mark you'll end up with hundreds of different charts. Everyone agrees the letter A or Alpha is dit-dah, but they cannot even agree that N, November, is dah-dit. Some show the difference between an open and a close parenthesis, others use the same character. There's charts that put dits-and-dahs inside the letters of the alphabet, but don't specify in which order the parts are heard. The Wireless Institute of Australia doesn't even appear to bother specifying, the FISTS Down Under Morse Preservation Society doesn't show a copy, the ARRL has an abomination on their website that you cannot even link to, the ACMA defines the end of transmission as a cross and then there are the special ones, survival charts and power point slides and using words...

How to start your own net ...

Aug 25, 2018 177


Foundations of Amateur Radio How to start your own net ... In the past I've talked about a weekly net I run, called F-troop. It's intended to be a place where new and returning amateurs find their feet, have a chat, test their gear, meet new friends, ask questions and sometimes get answers. If you want to come and join in, you're welcome to and I'd love to meet you. This net came about because I was new to the hobby and didn't find anyone running any on-air activity for people like me. I asked around and with some encouragement I decided to start an activity. Just like that. My point is that you can do the same. You can keep looking for that elusive group of people who share your interest, or you can get on-air and start a conversation. There's no forms to complete, there's no rules about how it has to happen, no expectations about how you run your net, just have at it. F-troop today looks nothing like it did on day one. On the first day I was on a simplex frequency and nobody could hear me. The next week I moved to a different day and to a local repeater at a different time. After doing that for a little while, we changed day and repeater again, because we kept running into other activities. I'm mentioning this because what you start today may look nothing like what it turns into tomorrow. Your idea might fail, or it might succeed beyond your wildest dreams. You may find new friends or find a different activity that sparks your interest. You could inspire another amateur to join the community, or encourage someone to get on air and make some noise. All around me there are nets, not in name, but in action. There's a group of people who get together during the week at 6am or so for about half an hour to chat on the way to work. There's a group who are learning Morse, another testing FreeDV, another chatting during the morning breakfast, another in the afternoon. There's a net for the emergency communications team, one for the local repeater group and there's a locally hosted net that attracts interest from all corners of the globe. I'm sure that there are others. I know from personal experience that you'll get callers who might not have much to say, but your presence gives them a reason to turn their radio on and participate, to get out of their house and talk to the world. They might not say much, but your being there might be a comfort. While F-troop is semi-organised, with a website, an advertised time and location, a dedicated host and regular callers, your net doesn't need to be any of those things. It can start as a regular chat that can grow, or it can fade away if there is no interest. Your hobby, your rules. One thing I can tell you is that hosting a net is very rewarding. I've seen amateurs start with very little to say, very unsure of themselves, grow into their license, expand their horizons, become skilled and find a new community to make their own. You don't need permission to start a net, you just need to decide to. I'm Onno VK6FLAB

Getting Started ...

Aug 18, 2018 197


Foundations of Amateur Radio Getting Started Don't get me started, Let's start this thing, Where do I start, Start me up, I could go on, but I have better things to do today, like starting a podcast. Amateur Radio is a hobby with an enourmous range of activities, interests, skills and experiences. If you're new to this hobby, you might find yourself standing at the edge of a precipous wondering what to do next. Where do I start, who do I ask, what's the first step, what if I fail and a myriad of other doubts and concerns. Would you be surprised to learn that this same dialog happens to every Amateur, all the time? Let's say that I'm an experienced member of the community and there is this new mode called FT8 that keeps polluting my PSK31 transmissions. I decide that it's time to see what it's all about. Or, imagine that you've been invited to come on a hiking trek for the first time with some fellow amateurs to activate a summit. Or, you hear about a new entity that has just been announced. Or, you decide that you need a new radio, a new antenna, a new head-set or a new logging package. Or, like me, you want to try again to learn Morse Code. For every activity you ever engage in, there's that moment of doubt, of concern, of challenge. In fact I suspect that it's exactly that thrill that makes people go ahead and pursue their hobby. That means that as a new amateur you're no different from an old amateur. You have the same level of concern and worry that others also have and you too can overcome those by just deciding to. So, what if you're not yet a new amateur? The first thing to note is that everybody who is an amateur today was at one point or another not yet a new amateur. For some that step happened yesterday, for others it happened over 80 years ago and for some that step lies in the future. At this point it would be helpful if I could point out a few resources, some things to look at, to listen to, or to engage with. If you're already on-air, listening, scan around and hear other activities. If you've managed to find the community on-line, you'll likely find other resources nearby, since we amateurs like to cluster, much like any other community. You'll also find on-line radios to hear HF, websites, discussion groups, mailing lists, interest groups, associations and clubs. If you came across this as a random event, see what brought you here and ask around. If you're stuck, ask a fellow amateur. I can introduce you to one right now. Hi, I'm Onno VK6FLAB and I'm an Amateur Radio Operator, pleased to meet you. Drop me a line and say hello, don't be shy. Just because you're not licensed is no excuse to get started. There are stories everywhere of those who start as shortwave listeners, or CB-ers, or come across the hobby in some other random way, like I did. The fact that you're here, now, means you've already found the community. Welcome. Seriously, Welcome to Amateur Radio. Now all you need to do is take another step, and then after that, another, and before you know it you're in and among other amateurs. There are many steps inside this hobby. Which ones you choose to take and at which speed are entirely up to you. This can be as formal or informal as you like. I'm Onno VK6FLAB

The mysterious three phase power ...

Aug 11, 2018 214


Foundations of Amateur Radio The mysterious three phase power ... There are times when you realise that you've always nodded your head when a particular topic came up and after doing that for long enough, you think you know what's going on. Turns out that, no, you didn't, but that the topic itself was interesting enough to learn from. In my case, Three Phase Power. I came upon this topic over the past month while I struggled with power interruptions, blinking lights, weirdness throughout my house. Turns out that it's been happening for a lot longer than I've lived here. After spending some time with the local power company, which I was told was filled with people who didn't care, turns out that they do, but they're busy people. After some back and forth, some logging, some finger pointing and head-scratching, the solution to my woes was to move me from the White Phase to the Blue Phase. I nodded and smiled and everything was well with the world. I know that there are three phases, Red, White and Blue. If you have overhead power in your street you'll likely notice four wires strung from pole to pole. One for each phase and one for neutral. Apparently there's a standard for which is neutral and the order, but there are too many exceptions for me to spell that all out here, so I'll move on. So, what's with these three phases? If you spin a magnet between two coils you have a generator. As the magnet spins, the magnetic field increases through each coil, then peaks, then reduces, and as the next magnetic pole comes along, the magnetic field reverses, increases, peaks, reduces, etc. If that sounds familiar, it's because I've just described a sine-wave. Every revolution of the magnet is a cycle and if you cycle, say 50 times, you get 50 cycles per second, or 50 Hz. For some countries it's not 50 Hz, but 60. Same thing, just faster. That single set of opposing coils and magnet is a single phase. If you add another set of coils, 120 degrees further along, you get the same phenomenon, completely independently from the first set of coils. That's the second phase. Rinse and repeat for the third phase. To get that power to the rest of the suburb, you need to run a single wire for each phase and a common neutral wire, giving you the four wires that you see on a power pole. Theoretically you could run with more phases, but you need to run more copper into the street, so power companies stopped at three. You can think of these as three completely independent circuits, but they all share the same neutral, so there are some subtle interactions, like if the neutral becomes disconnected, bad news happens, especially in a place like Western Australia where ground conductivity is very poor. In a normal home you'll get fed by one of those phases, in my case I changed over from the white phase to the blue phase. This means that each phase has a different set of users in the street. Roughly a third are using each phase. Looking at the actual voltage and current that comes through at high enough resolution and you'll begin to recognise it as an RF spectrum with harmonics, variations, interference and other artefacts that make power show up as a varying feast, rather than the rock-solid expectation of 240V, 50 Hz you see on the sticker. Three Phase Power, now you can nod along like I did and know how it actually works. I'm Onno VK6FLAB.

Water and Electronics a match made in hell ...

Aug 4, 2018 307


Foundations of Amateur Radio Water and Electronics, a match made in hell ... It's been raining around here for a while now. Not in the order of 40 days and 40 nights, but significant. Mind you, I have lived in a place where it rained every day for 57 days, but I digress. Water, plenty of it and often in all the wrong places. Being a radio amateur you come across water in many aspects of the hobby, sometimes it comes in handy, like lubricating your throat while you're calling CQ, or as a ground plane for an antenna, other times, not so much, like when it enters the shack and causes the black smoke to escape from your pride and joy. As I said, I'm no stranger to rain and in my travels I've encountered plenty of it. I managed to travel around Australia for a couple of years and I took with me a two-way satellite dish with sensitive electronics attached. Living in Australia I planned for dry. This place is dry. Often very much so, but as it turns out, dry doesn't mean without humidity, storms, rain or in one case hail. These experiences told me a little about protecting electronics from the weather. I should add a disclaimer here, I'm not a certified weatherman, nor am I certified in waterproofing, water ingress, or any other guarantee. So, if you do as I say and it breaks, you get to keep both halves. That said, I have some thoughts on the matter and I wouldn't be me if I didn't share them. Water is generally everywhere. It gets into everything and it's one of those silent killers. Electronics and water rarely mix, unless you submerge the electronics in mineral spirits, or if you seal your electronics in circuit board lacquer. Even then, there are few guarantees. The best you can hope for, in my experience, is to plan for failure, hope for success. Finding where water gets in is often the hardest part of keeping it out. Sealing off your electronics from the world in a waterproof anything will trap heat, which in turn will cause condensation, which will ultimately cause rust and destruction of your priceless electronics. Giving your stuff time to acclimatise is a very good idea. For example, if you have a radio stored in your garage and you bring it indoors, leave it there for several hours, if not overnight. Unless you live in Alaska with an in-floor heater to prevent your engine block from freezing, your garage is cold, your home is warm, the combination causes condensation. Alternatively, if your garage is hot, and your home air-conditioned, the reverse is true and condensation will still happen. Water has a habit of finding its way into anything, encouraged by gravity. That means that a length of coax, run into your wall will attract a stream of water along the coax, straight into the connector and into your wall, or between the core and the braid, or into your radio, or some other undesirable place. If you create a low point before the connector, like a drip-loop, a place where water would have to go up before it can do damage, you'll likely solve the issue, but don't discard the effects of wind which can cause water to go uphill. Connectors are magnets for water. Most connections in use in amateur radio have little or no waterproof rating. There are special waterproof connectors about and you may consider using those, but alternatives like self-amalgamating or rubber tape, which you wind tightly around a connection and in doing so, stretches and glues itself together to keep the water out. These tapes are generally not stable in the ultraviolet of the sun, so you may have to wrap that sealed connector in another layer of tape, plumbing or electrical tape is one solution. Based on the experience from national coax installations, the way to do this is with three windings of rubber tape, followed by two of plumbing tape. Think of up as towards the weather and down as away from the weather and make the windings like this: Wind the rubber tape three times around the connector, up, then down, then up again. Seal...

Heated Elements and Circuit Boards

Jul 28, 2018 216


Foundations of Amateur Radio Heated Elements and Circuit Boards Recently I had a conversation with a group of amateurs, ranging in experience from newbie to salty, from purchase to build, from buy to scrounge, in other words, the whole range. One person in the group asked about how to get started with soldering. Their first harmonic had just been granted a license and they wanted to encourage the new amateur to build something, anything. That in turn started a whole conversation about the how, where, why and what of the way of the heated element and its application to a circuit board. In 2012, almost exactly two years after obtaining my amateur license I purchased an electronics kit. The kit was sold by my local electronics store and was intended to become a High Precision LC Meter. The electronics store packages together many of the schematics that are published in Australia's Silicon Chip Magazine and in this instance, it also came with a lovely case, build instructions and a review from someone who had built the kit, John, VK3FJBX. The whole thing cost me $90 at the time and as far as I was concerned, that was a bargain. These days I might have considered it a little high, but the end result was an LC Meter that does what I need and works as described. The process of building the contraption was not complex, in fact, I think the single surprise was the need to purchase a Component Leg Bending Tool, a fancy name for a $2 tapered block of plastic with little indents that you can use to bend the legs of a resistor so they match the holes of the circuit board. As projects go, this one was a success. I bought it, I built it, I put it together, powered it up and the black smoke stayed inside the components and the meter displayed numbers that matched up with what the label on the component I was testing said. That in an of itself is a story of success. I can point at several other kits sitting in a box, still as bags of components, never assembled, lost interest, got distracted, too hard, not viable, missing bits, whatever the excuse, gathering dust until magically one day they'll be needed for when the apocalypse is here, or the garage explodes from too much stuff and I'm forced to donate it to the world. As my life experience increases, my hands are becoming less steady. I now have a magnifying lamp, not enough clamps and less patience for silliness, so, my kit building is at an all-time-low. Mind you, it's not that I've stopped building or experimenting, instead I'm writing software, investigating new and exciting tools, like a random online circuit simulator I came across during the week. I did want to tell you what it's called, but it's down at the moment and I don't know if it was hugged to death by well meaning amateurs who came to visit. Search with your tool of choice for "Electronic Circuit Simulator in the Browser" and you'll be spoilt for choice. In addition to several browser based simulators around, there are also offline applications you can download and run, even tools you can spend actual money on. All told, several options for learning how to build a circuit, how various things work together, including showing simulated oscilloscope traces, so you can see what your latest contraption actually does. The art of building, the skill of soldering, the pursuit of design is hampered by one thing, and one thing only. Your ability to get out and start. So, what are you waiting for? I'm Onno VK6FLAB

The Contesting Coin Toss for the rest of us

Jul 22, 2018 232


Foundations of Amateur Radio The Contesting Coin Toss for the rest of us If you've been part of the amateur community for a while and have heard me talk on matters of contesting, you'll know that I'm an avid contester and that for me it's better than sliced bread. Of course, I'm me and you're not. If contesting isn't of any particular interest to you, the hobby of amateur radio is big enough for at least 999 other attractions. I talk about them regularly. If you're on the fence, or if you're unsure, or if you are not enamoured with this whole contesting thing, then today I'd like to ask you to consider another aspect of this activity. Don't worry, I'm not going to tell you to participate in a contest. As I said, there are many other activities within the hobby. For example, testing propagation is a recurring theme, as is testing your gear, your radio, your skill and doing all manner of other amateur things. For many of those activities having another person to test with is often a way to get a result and if you find yourself on a lonely Saturday looking for a friend to help, I have a suggestion to make. It relates to contesting, specifically those on air. It turns out that there are radio amateurs on air almost all the time. Imagine that. Better still, when there's a contest on, there are even more radio amateurs around, all clamouring about, trying to make contacts, trolling up and down the bands, making an effort to hear new stations, calling CQ, generating signals from all over the place. Here's the thing. There is no rule that says that you have to be participating in the contest, or even log contacts for the contest, but there is no harm in you using the airwaves for your own enjoyment. Turns out that if you get on air during a contest, you can use that for example to do testing of all manner of things. If you've run out of things to test, you can use it to learn things, like how to use the RIT or "Receiver Incremental Tuning", something Yaesu calls the Clarifier, or the IF offset, or the noise-blanker, or the noise-filter, or the A/B VFO, or what ever it is that floats your boat. There are people all around you, getting on-air, making noise and you can join in with the fun. You can learn about the directivity of your station, observe how propagation changes, how the different bands react depending on the time of day, the solar cycle, or magnetic flux. If you have the opportunity, you can monitor the grey-line and observe its effects on what you can hear. You can look at a DX Cluster and see what you can hear, compared to what stations other amateurs are reporting. You can measure signal strengths, the impact of the AGC, test you battery life, your mobility, the layout of your shack and if you feel the urge, you can even log a rare station and add it to your log. No rule anywhere says that you have to participate in a contest, but why let a good opportunity go to waste? If you're an avid contester, you might think that I'm advocating that we fill the air with time wasters, people who shouldn't be there, people who are not worth your attention. I'm here to tell you that just because you're in a contest, doesn't mean that the rest of the world is and just because you want to make an exchange, not everyone else does. If I find myself having a conversation mid-contest with someone with a story to tell, I can participate in the discussion, or I can change the dial and call CQ contest somewhere else. The bands are a shared resource, for those who contest and for those who don't. The interesting thing in all this to me is that there seems to be a perception that you can only fall on one side of the coin. You're either a contester, or you're not and never the twain shall meet. That just makes no sense to me. There's an opportunity to sit on either side of the divide and harness both at the same time. I'm Onno VK6FLAB

Programming Repeaters ... Revisited.

Jul 15, 2018 272


Foundations of Amateur Radio It seems that when you categorically state something, like I did recently, you get emails and feedback, almost immediately, pointing out the folly of your assertion. Within the context of setting up your radio, an hour before you go away, I intended to convey: "One thing I can categorically state is that programming your radio manually just before your holiday is really something that you should try and avoid." That's not what I actually said. I missed out on the "just before your holiday" in that sentence. The upshot was that I received lots of feedback, some tips and different suggestions on how to do this and do it well. As I hinted at, you should know how to program your hand held. It's almost an essential life-skill. I generally take a copy of my manual with me, either on actual paper, you know, dead-tree variety, or as electrons as a PDF on my phone or other screen-based gadget. That doesn't mean I like programming my radio. In fact I will be so bold as to assert that I hate manually programming any of my radios. The process is tedious, non-obvious, with a process seemingly written for ENIAC in 1946 when you toggled bits on a panel to program a computer. Yes, that's a slight exaggeration, but not by much. Anyway, given that this is such a chore, I tend to avoid it like the plague and only in case of an emergency, do I break out the user manual and poke through 17 pages of arcane button pushing-fu, to get the job done, without hopefully clearing a memory I had programmed before. One of the emails I received, in fact the first one, was from Andrew KF7CCC. He very kindly pointed out the error of my ways, and I agree with him. One of the points that Andrew and others have made is that a defining characteristic of being a radio amateur is that we're frequency agile. That's not something that most other radio users are familiar with. They have a list of channels to pick from and switch between them. In amateur radio we have access to a VFO, a Variable Frequency Oscillator which allows us to change frequency at will. Of course we should all be able to change frequency as the need arises. Sitting on two different channels, pre-programmed into our radios is like being users, rather than inventors of radio, shock, horror. Andrew also mentions a book he's written. In one of the opening paragraphs he says: "This book shouldn't exist." and goes on to explain why the "Handheld Radio Field Guide" is a book that should be made obsolete by sanity entering into the process of programming a radio. I agree with the sentiment. We really have this insane configuration where each brand does it differently, and often within a brand, each model is different. Andrew makes a series of suggestions in his book and I think it's a great starting point for discussion. As I started with, I received lots of feedback. One suggestion was that radios should have an on-board GPS and should automatically know, based on location, which repeaters are nearby. That in turn will create a debate about where the list of repeaters comes from. Such a system appears to exist. At least one manufacturer, Icom does such a thing, but opinions appear to differ on its effectiveness. Another was that you should program the repeater networks into your radio, so when you head away from your home, you have access to the widest range of options. All this talk of repeaters started a lament by some that repeaters are dead and that they are not being used. Others said the opposite and welcomed new calls regularly. I am an IT geek. I wonder if we could create a ping of sorts where a radio transmits a broadcast request for nearby repeaters and that each in turn sends a response, collected by the radio and neatly added to the list of local repeaters. If it sounds familiar, that's because in computing we do this all the time with all manner of different gadgets like printers on our local network. In fact, your radio could just listen for...

Which repeaters should I put into my hand held radio?

Jul 8, 2018 232


Foundations of Amateur Radio A regular question from people who go on holiday is: "Which repeaters should I put into my hand held radio?" If there was infinite amount of memory and time, the answer would be simple - All of them. If it were that simple, I wouldn't be talking about it and you wouldn't be asking the question, so given that it's not that simple, what options do you have for dealing with this question, generally an hour before you pack up your suitcase to leave on that trip to another location. For me, my first effort was to try to find a list of repeaters for the new location. Failing that, I ventured onto the national association and downloaded their list, which I might add, was woefully out of date, but I wasn't to know that when I found it. I then fired up a copy of the cross-platform CHIRP programming software, pushed all the repeater frequencies into my radio and called it a day. I did have the benefit of a radio that was able to group memories into separate so-called banks, which allowed me to be able to select a particular bank for each state, my own state, VK6 was, and I might add, still is, in bank 6. VK5 is in bank 5 and so-on. The advantage of this arrangement is that I can select a bank, set my radio to scan in just that bank and I can hear all the activity that's happening within range of my hand held. Pretty useful when you're on holidays in a new location. If your country doesn't quite break-down into neat little groups like that, or if you cannot break your hand held radio memory into banks, you might have to come up with a different strategy. You could for example, create your own equivalent banks, 100 to 199 is bank 1, 200 to 299 is bank 2, etc. Or if you have 50 states to worry about, you might allocate 101, 201, 301, 401 etc. to state number one and so on. Of course that will start an argument about which state is number one, but I'm sure you can work that out for yourself. Another suggestion is to query the local license database, in Australia the ACMA database, and get a list of currently licensed repeaters. If that's not your style, you could download a mobile phone app, something like Repeaterbook. You can even link your mobile to your radio and have the app set up the frequencies for your location. One suggestion I came across the other day is to do none of this and to just program in all the possible repeater pairs. There's not that many possibilities and setting your radio to scan will unearth any activity on what ever standard pair is being used at the time. This won't get you completely out of the woods, since some repeaters require a CTCSS tone of some description, but several hand held radios have the ability to decode the tone. You could get fancy with pre-programmed tones in different memories, but I'll leave that as an exercise for you to imagine. In the end, finding amateurs in a new location is a lot like finding amateurs in your home town. They're around, you just need to find them. Visiting a local club works at home and it works just as well while you're on holiday, sometimes even more-so, since you'll be a visitor and many clubs like to be on their best behaviour for new comers. One thing I can categorically state is that programming your radio manually is really something that you should try and avoid. Not because it's not possible and not because it's not a skill you should have, but because it's error prone and there's nothing quite as frustrating as programming in the wrong frequency without having the ability to fix it when you're in the field. One tip. CHIRP allows you to create as many different frequency files as you like. There's nothing wrong with making one fit for purpose for this outing and having a different file for your home location, or for a specific contest or DX activity. A final bonus tip. CHIRP generally uses the microphone and headphone sockets for most hand held radios. Setting the volume correctly is a must. If you set the volume too...

How to get the best Amateur Radio gear?

Jul 1, 2018 234


Foundations of Amateur Radio How to get the best Amateur Radio gear? A recurring question for new entrants to our hobby, and truth be told, some experienced ones as well, is: "What's the best hand held to buy?", or the best antenna, or the best base station, the best coax, the best mount, the best software, the best something. There's a principle in Engineering, Good, Fast and Cheap, pick any two. You can have Good and Fast, but it won't be Cheap. You can have Fast and Cheap, but it won't be Good. You can have Good and Cheap, but it won't be Fast. The concept of Quality is balanced between these limits. With that in mind, answering the question in search of the best is already a trade-off. To muddy the waters further, there is an economic principle related to pricing. It goes a little like this. If you sell an amateur radio gadget for $50, there's a group of people who will buy it. There's a group of people who would have paid more for the same thing and a group of people who can't justify $50. If you make the price higher as a manufacturer, say $75, you'll get more money from some people, but the group of people who can't justify the price will get larger, so you'll sell less gadgets. If you make the price $25, you'll sell more gadgets, but you won't capture the income from those who were prepared to pay $50 or $75. So, as a manufacturer, you make three gadgets, one for $25, one for $50 and one for $75. They're all essentially the same, but the market will lap it up. Of course, between $25 and $50, there's a group of people who would have been happy to pay more, etc. etc. Ad-infinitum. That's our amateur radio gadget market place today. The price points might not all be taken up by the same manufacturer, but the market price for say a hand held radio goes from somewhere around $40 to over $1200. You'll find the range completely filled with offers. As an aside, your local telco is doing the same thing, as is your mobile phone manufacturer, your internet service provider and your car manufacturer to name a few. So, now what? We're looking for the best gadget. Since you're going to be the one using it, your definition of best is going to be different to my definition. I care about my hand held being waterproof, but I don't care about having a torch, a compass, a thermometer or a GPS on board. You might want to take it hiking, where I'm more likely to use it on a field-day. This means that asking another amateur, "What's the best?", is a recipe for discussion. Some will be adamant that their selection is superior to that of another amateur, but you should now already know that this is completely subjective. If you go down the scientific route, you might use receiver sensitivity as a metric. If that's all you care about, the choice is easy, list them all by sensitivity and pick the one that's the most sensitive, but the battery life might be abysmal, or it might not use the frequency you care about, or it might have some other extra function you are paying for, but don't care about. We get down to picking from a list. If you're anything like me, and let's face it, we're all amateurs here, you'll get to a point of making a list of the options you have. Selecting the best antenna, the best power supply, the best base station, hand held, mobile, car, service contract, you name it, it always comes to a list. Here's how to pick. Is option A better than B? Yes? Remove B. Is option A better than C? No? Remove A. Is option C better than D? No? Remove D. Is C better than E?, etc, etc. You might be concerned about the ones that you've removed. You already decided that there was a better option than the one you removed, so ignore them, they're just muddying the water. If you want to ask another amateur what they bought and why, that's a whole field of exploration, but if you ask them what's the best gadget, that's just asking for trouble. I'm Onno VK6FLAB

The Power for your Radio

Jun 24, 2018 289


Foundations of Amateur Radio A question that occurs more often than you might think is one related to powering your radio. It comes in a few different flavours, like: "I want to install a radio in my car, how do I power it?", or "I want to operate portable, what's the best way to power my radio?" or "What power-supply should I buy?" There are many more versions of this, but they all come down to the same underlying challenge. I spoke about sizing a battery a couple of years ago, but that's not the only consideration. If you look at the power specifications of my Yaesu FT-857d, you'll see 13.8V DC +/- 15%, Negative ground, 1 Amp on Receive and 22 Amp on Transmit. Based on this I purchased two 26 Amp Hour batteries and a 45 Amp variable power supply. My amateur license restricts me to 10 Watt and I tend to operate using 5 Watt. On receive the actual draw, specified in the documentation at 1 Amp doesn't go above 0.5 Amp in typical use. Transmit, specified at 22 Amp doesn't go above 3.6 Amp at 5 Watts and at 10 Watts it's still only 4.5 Amp, so my 45 Amp power supply is slightly overkill, by a factor of 10. By the way, that's an FM carrier on 2m. Different modes and bands have different current draw. I should make mention of the duty-cycle, that is the difference in time spent transmitting and receiving. A 100% duty-cycle means that you're transmitting all the time, 50% means half the time and 25% means that for every minute of transmission, you'll spend three minutes listening. There is more to the duty cycle, in brief, AM, FM and RTTY are 100% duty cycle modes, CW is a 40% mode and SSB has a duty cycle of 20%. So if you're listening half the time on SSB, your duty-cycle is only 10%. At this point you should at least understand that what the manufacturer says on the box and what your radio actually does is entirely dependent on your use case. I have no doubt that there is a way I can operate my radio so it draws 22 Amp. I'm not quite sure how, but I'm sure it's possible. Sizing aside, there are other things you need to consider. If you're in a car, do you wire the contraption directly to your car battery, or to a secondary battery? Should it be connected directly, or via the accessory switch? Should you get a DC to DC power supply, or some other technology? Also, not all cars are 12V, not all cars have their body as earth and the thicker the wire between the battery and the radio, the better. My decision, given that I live in a country where distances are non-trivial, and in a state bigger than Texas, in fact Western Australia is bigger than Alaska, Texas and Minnesota combined, I decided that it would be prudent to make the power supply for my radio completely separate from my car. I have a toolbox in the boot, that's the trunk if your regulator is the FCC, which contains two 26 Amp Hour batteries. I take it out to charge and put it back when I need it. Other solutions include second batteries with disconnect on low charge circuits, manual and automatic ones, direct connect to the main battery and variations on that theme. In shacks I've seen batteries which are constantly charged connected to a radio and dedicated power supplies bordering on being a local sub-station to ensure that enough of the good stuff makes it into the radio and out to the antenna. For portable operation I've seen Lithium in several different flavours, car start boost batteries, mobile phone USB batteries, remote control car batteries, and the like. If you have more than one, bring some red Velcro and use it to mark the flat battery. One of the things you'll really only be able to learn after doing it is finding out what the noise level is that a power supply generates. A battery generally doesn't make noise, but the charger or up-converter might. Inverters are often a great source of HF noise, the cheaper the more noise, so test before you buy. Also, none of what I've said so far considers emergency preparedness, which is a whole other topic...

Get a Contesting Buddy

Jun 16, 2018 239


Foundations of Amateur Radio There is a solitude about amateur radio. Sitting in your shack, listening to the bands, trying to locate an elusive station and if you're doing a contest then even that can be something that you do alone. Don't get me wrong, I like my own company as much as the next introvert, but there is much joy to be found in finding a companion. Over the years I've participated in group activities, camping, field-days, contests, activations, antenna building, ham-fests and the like. These activities have been excellent and I highly recommend that you attempt to find a local community where you can connect with other amateurs to find common ground and explore this hobby together. Last week I did a contest with a friend. Each on our own, but doing the same contest at the same time. The contest itself was what can only be described as a fizzer. For my 8 hours or so of operating I managed a grand total of one contact and that wasn't even with my friend. What made the experience one to remember is that I wasn't alone in the activity. I wasn't the only one having the experience. I was able to share my single contact and know that my friend didn't fare much better, that they had been in the same boat and came out just as wet. It's not the first time I've done a contest with a single friend. This time we did it as two stations, each under our own callsign, but previously I've participated in contests where it was just two of us that were working the same callsign, both trying our best to contribute as much as we could. The thrill of doing this is like nothing else I've experienced and I would highly recommend that you try it. My tips for success are that you agree on a common understanding of why you're there. If one of you is wanting to lark about and the other is serious the experience will end in tears. One of the things I've done in the past is to agree on operator rotation. For one contest we set a hard limit of two hours per operator and between us we covered most of the 48 hours of the contest and we managed enough sleep to stay sane. Operating two radios doesn't in my experience work very well if you're both working in the same shack. That's not to say that there is hardware that can fix that, but so-far it's been elusive at best and at least frustrating. My quest for coax-stub filter bliss continues. Motivation is a big deal. Encouraging the other person, making them a coffee at 2am in the morning, listening in and laughing helps and makes the experience one of joy. Learning and observation is a useful spin-off from this. I've done this with people with more, sometimes decades more, experience than I and with those who have less experience. Giving feedback, write it down, don't interrupt the contest unless it's a rule breaker, and talking about it after the fact will make both of you better operators and that's not a bad outcome by any measurement. Back-seat driving isn't OK. If the other person is operating a pile-up, let them operate it, their ears are not yours and your interjection of a callsign you heard is likely to end up in frustration for both. That's not to say that you can't do this together, just talk about it before you start "helping". One of the most rewarding aspects of this whole process is that you get to see another person doing what you're doing and the differences in style between the two of you is often a learning experience for both, not to mention a shared history that will continue well after the contest is finished and forgotten. Over the years I've now managed around half-a-dozen contests with a single other person, sometimes in their shack, in a club shack, on a camp-out, or in a car mobile and I have to say that it's the most fun I've had along the way. For all I know that kind of fun can be had in a contest station that has an operator for every band with equipment coming out of every corner, but I haven't experienced that yet, so I can't comment. Find yourself...

Logging of a Different Kind

Jun 9, 2018 227


Foundations of Amateur Radio Logging of a Different Kind We as radio amateurs log things. We log our contacts, we log our progress towards an award, we log how many different countries we've contacted, which stations we heard with WSPR, how many kilometres we managed per watt, which stations were in a net, what callsigns received a QSL card, what location we're in when we made a contact. You get the point, we log things, many things and for many different reasons. Here's a log that I started last week. An asset log. You heard me, an asset log, a thing that logs what amateur radio stuff I have, when it came into my life, where it came from, what brand it is, what model, what the serial number is and if I spent money on it, how much money I spent. It shows things that I've loaned to other amateurs and it shows things that are on loan to me. It started with a conversation about a silent key. That's what we call radio amateurs who have died. The idea of a silent key is one that reminds us that everyone is unique, that every manual Morse code transmission has a particular feel and that this is unique to every amateur. Once that particular combination of speed, tone and pacing is no longer heard, they're said to have become a silent key. I've been an amateur for a few years now and in that time I've seen the process that happens once an amateur becomes silent play out over and over again. In my experience it's not pretty. It almost always appears to end in something akin to a feeding frenzy where the person who got in first grabs the best stuff and leaves the rest for the next person. Rinse and repeat until there's nothing of value left. It leaves me with a bad taste in many ways. For one, the family who is left behind might not know or understand that there is a monetary value associated with what's often referred to as "grandpa's gear" and they might just be in need of some extra financial support in their time of mourning. Another aspect, if there is no actual need for money, is that the person who's shack is being dismantled might have an idea on how they would like to see their hard work live on. They might want to donate it to a particular person, an organisation, a club, a school, or some other destination of their choosing. All that can only work if there is a list of stuff. Having a family member construct that list is going to be a tough ask, unless you're fortunate enough to have more than one amateur in your household. Asking another amateur to make the list creates a load of work with at best guesses of age and value. The only person really qualified to make the list about your shack is you. Last week I started the list on a spreadsheet that I'll share with my family. I'll add to it when more stuff arrives and if I feel the need, I can remove stuff that has moved on. I'm not in the position to add new amateur equipment to my shack more than a few times a year, so maintaining this list isn't going to be an onerous task and I could imagine that the list expands to include tracking which equipment went with me on a field-day, which I have to tell you is always a challenge to track. As a bonus, the list can be used in the case of loss or theft and for insurance purposes, so it's not just for when the time comes that we become a silent key. To get started, make a list of what you can see around you and keep adding stuff. If you keep accounting records, they can be used as a source of information too. We log lots of stuff and I think that adding an asset log is something that will add to any amateur shack and it could form the basis of a legacy that you might leave behind. I'm Onno VK6FLAB

The Internet of Digital Radio

Jun 2, 2018 417


Foundations of Amateur Radio The topic of how radio evolves and embraces available technology is one that describes the hobby itself. From spark-gap through AM, SSB and FM our community picked up or invented solutions to make communication possible. When the internet came along it too became a tool ripe for picking and in 1997 a connection between a radio and the internet was made with the Internet Radio Linking Project or IRLP when Dave VE7LTD, a student at the University of British Columbia, joined the UBC Amateur Radio Society. Using a radio, some hardware and a computer, you could send audio between radios across the internet. Since then this field has exploded with D-STAR, Echolink, DMR, AllStar, Wires, CODEC2, System Fusion and Brandmeister. At a glance they're all the same thing, radio + internet = joy. Looking closer there are two distinct kinds of internet radio contraptions, those where the radio is digital and those where it's not. IRLP is an example of an analogue radio connecting to hardware that does the encoding into digital and transmission across the internet. At the other end the reverse process, decoding, happens and another analogue radio is used to hear the result. This encoding and decoding is done by a piece of software called a CODEC. If we continue for a moment down the analogue path, Echolink, AllStar and Wires do similar things. In 2002 Echolink made its way onto the scene, similar to IRLP, but it didn't need any specialised hardware, any computer running the Echolink software could be used as both a client and a server, that is, you could use it to listen to Echolink, or you could use it to connect a radio to another Echolink computer. AllStar, which started life in 2008 went a step further by making the linking completely separate. It uses the metaphor of a telephone exchange to connect nodes together, which is not surprising if you know that it's built on top of the open source telephone switching software Asterisk. In 2012 or so, Yaesu introduced Wires which is much like Echolink and AllStar. There are servers with rooms, not unlike chat rooms, where you connect a node to and in turn your radio. Blurring the lines between these technologies happened when you could build a computer that spoke both IRLP and Echolink at the same time. Now you can also add AllStar to that mix. Essentially these systems do similar things. They manage switching differently, handle DTMF differently, use a different audio CODEC and handle authentication in a variety of ways, but essentially they're ways of connecting normal hand-held radios, generally FM, to each other via the internet using intermediary computers called nodes. Before you start sending angry letters, I know, there's more to it, but I've got more to tell. While Dave was busy in Canada inventing IRLP back in the late 1990's, in Japan the Ministry of Posts and Telecommunications funded research, administered by the Japan Amateur Radio League into the digitisation of amateur radio. In 2001 that research resulted in what we know today as D-STAR. Two years later, ICOM started developing D-STAR hardware which resulted in actual physical radios less than a year later. Today you can get D-STAR hardware from ICOM, Kenwood and FlexRadio Systems. Unlike the other technologies where the audio was converted at a central place, in D-STAR the audio is encoded in the radio and a digital signal is sent across the airwaves. That in turn means that the software that does the encoding, the CODEC, needs to be inside the radio. Since the information is digital right from the point of transmit, you can send other information, like GPS locations and messages along with the audio. In 2005 DMR started life as a group of companies, now up to around 40, agreeing on some standards for digital audio in much the same way as D-STAR. Mostly in use by commercial users, DMR has the ability to have two users simultaneously on-air using alternate channels by having separate...

How to find other Amateurs on Air

May 26, 2018 272


Foundations of Amateur Radio Where are all the Amateurs is a question that I am asked regularly by new entrants into our community. The journey most new amateurs go through and the one I followed starts with becoming interested, getting a license, buying a radio, setting it up and then turning on your radio. If you're lucky you are at this point surrounded by other amateurs, hopefully in a club setting, or you have a friend nearby and you're off and running. The reality is likely that even after a successful first on-air adventure, you'll be on your own in your shack asking yourself where everyone went. I've talked in the past about picking the right day, for example, a Wednesday is likely to have less people on air than a Saturday, but that's only part of the story. One of the things that had never occurred to me until a while after I became an amateur is that listening is a really important way to find other amateurs. Let's start with some things that might not have occurred to you. Most amateurs are not in your time-zone. There is amateur radio activity almost all the time, 24/7 on whatever the appropriate band is. Not all bands sound the same. What worked yesterday might not work today. This hobby isn't exact or precise, that is, there are an infinite number of variables which each affect the experience either positively or negatively and even if you used your radio in exactly the same way with the same settings on the same band in the same location at the same time with the same antenna, the landscape around you has changed, the ionosphere is a lot like the ocean, flat and calm one day, storms and waves the next. Those things aside, each of which could be a whole story is still only part of the story of finding other amateurs. There is a tendency for new amateurs to think of frequencies as numbers, as parameters to add to your radio, pick 7.093 MHz, pick 21.250 MHz, or 28.500 MHz, they're just numbers, things that you pick with your radio, set-up your antenna to and listen. That's part of the story, but there is another part. If you think of light and you go from Infra-red through visible light through to Ultraviolet light and beyond, all you're doing is changing a number, from somewhere around 300 GHz through to 3 PHz. It's a long dial in amateur radio terms, but the difference is just a number, right? It should be obvious that the human day-to-day experience of Infra-red and Ultraviolet are completely different. The 28.5 MHz 10m band frequency is on the same spectrum as both Infra-red and Ultraviolet but you don't expect to see these frequencies or use them in the same way. The same is true for amateur radio bands. The 80m band, the 40m band, 15m and 10m are all different. They're in use by radio amateurs, but their experience is also completely different. Some are good for day-time communications, others for night-time, some work regardless of the solar-cycle, others need solar flux. Magnetic activity affects some bands more than others and that's just the tip of the iceberg. If you have a hand-held radio and you're used to listening to a local 2m repeater it's likely that you've set up the squelch on your radio to hide noise and your day-to-day experience is one where there is silence when nobody is talking. You might tune to 15m and look for the same silence, only to learn later on that noise is what you're actually looking for. The sounds that the 10m band makes is different than the 80m band, the 20m band responds differently to changing conditions to the 40m band and every different radio you use has a different feel, so what you're used to with one radio will be different on another. All this to say that the way you find other amateurs is to listen. You'll need to get a feel for this thing, a sense of opportunity. I've compared amateur radio to fly fishing on more than one occasion. Standing up to your arm-pits in a river tossing out a line, finding a bite will be different depending on the...

How does a waterfall display work?

May 19, 2018 200


Foundations of Amateur Radio With computers becoming more and more ensconced within the confines of our radio shack the variety of information available is increasing regularly. The introduction of a waterfall display has dramatically simplified the process of detecting what the activity level is on a particular band. If you've never seen a waterfall display, it's often a real-time, or nearly real-time display of radio activity. Leaving aside the mechanics of how this comes about, or how much you see, generally it's presented as a picture that changes over time. In reality it's a very compact way of showing a lot of information. You can think of it as a chart, showing the horizontal axis as frequency, the vertical axis as time and the colour as signal strength. So as you look from left to right you'll look at higher and higher frequencies. For example, the left side might be 7 MHz and the right side might be 7.3 MHz. Halfway along is 7.150 MHz. Similarly, now, as in zero seconds ago is at the top of the chart and 1 minute ago is lower. Depending on how fast you've set it to update the whole screen might represent 10 seconds, 10 minutes or 10 hours of information, entirely flexible, entirely configurable, entirely arbitrary. If you think of the colour black as having no signal strength and the colour red being maximum signal strength, then the brighter the colours, the more signal there is. A morse code signal might turn up as a series of dits and dahs running down the screen, with the oldest one being at the bottom and the newest one at the top. An AM signal might show up as a thick line with a bright colour, that's a high signal strength in the middle and lighter colours or low signal strength towards the edges. Every mode has its own visual characteristic and there are even modes that allow you to read information within a waterfall display. One of the other things you'll see in a waterfall display is strange artefacts, things like a diagonal line for example. If you think of what a diagonal line represents as a radio signal, it's something that has a strong signal at a particular time and frequency. A moment later it's changed frequency and a moment later it's done it again. The steepness of the line is dependent on two things, the speed that the frequency changes and the speed that the waterfall is updating. Before waterfall displays, the way you'd experience such a signal would be something that flashes up as a low to high swoop, or a high to low swoop, depending on your listening mode and the direction of the frequency change. So what is that signal? Well, it's likely to be something called an Ionospheric Sounder. It does what you think it does. Ping the ionosphere across multiple frequencies. The station doing this is listening for a return echo to see if the ionosphere is reflective for that particular frequency at that particular moment. The information can be used to create a map of what the ionosphere is doing right now, which in turn is used to figure out what frequency to use to make a contact. I should also mention that there is a signal identification wiki which shows and plays various identified and unidentified radio signals, hours of fun for the family. I'm Onno VK6FLAB

Why do you contest?

May 12, 2018 206


Foundations of Amateur Radio The other week I participated in a contest. This particular contest was on the 80m band, around 3.5 MHz. The contest itself, while worthy of a mention, the Harry Angel Memorial Sprint, runs for 106 minutes and commemorates every year of Harry's life, at the time, the oldest radio amateur in Australia. I made two contacts. Count 'm and weep. Two. So, you could do the thing that I might have done in a previous contest, smiled, thought, "Wow, that's not very many contacts." and got on with life. You're free to do that, but I wouldn't be talking about this today if I shared your view. In fact I'm sure that in my activities as a radio amateur I've managed to learn, and in some ways unlearn some things along the way. In a previous contest I might have operated a club station, made contacts a plenty, added to the overall club score, added new countries and multipliers, had some good natured ribbing to go along with it and walked away with nothing to show for it on my own log. The truth is that for many of my on-air contest activities I made contacts for other callsigns, those of fellow amateurs, clubs, special events, you name it, I made contacts. Don't get me wrong, there's absolutely nothing wrong with that, nor was it a waste of time. I learnt loads from those experiences, but my own callsign log rarely, if ever, got an outing in such activities. So, this contest was for me. For my callsign, using my radio, my antenna, my location, my patience and my skills. I did the contest because I wanted to, for me. As you know, I'm a fan of operating QRP, that is, low power, so this contest I used 5 Watts, a Yaesu FT857d, a multi-tap vertical antenna, screwed onto a mount on the back of my car, parked next to a river with water to the East of me, so I could benefit from any gain that water nearby might offer me. As an aside, I'll talk more about water and gain at some other time, because it appears that not is all as my handed-down in hush-hush terms from mentor to me, would have me believe. I don't yet know enough to point at anything, but there's more than apparently meets the eye. Watch this space. Anyway, two contacts. Not even that far from me, about 230km South and 20km North East. Both with SSB. I heard about 20 stations, some up to 3,500km away, but they were dealing with S7 noise where I had none. That's right, no noise, S0, in the middle of the city. In addition to a heart stopping moment when the lights came on in the car park where I had set-up, my biggest fear being noisy lights, which turned out to be unfounded, my other take-aways were that I really should bring spare batteries for my LED lamp, and that I called it an LCD lamp last week. Not sure what I was thinking. I logged using pen and paper, in doing so I was upholding a fine tradition of radio amateurs everywhere, pen and paper is by far the most popular method of logging and with two contacts made, that's not surprising. I'm still on the lookout for sensible logging on a phone, but so-far that's eluded me. Perhaps I should write one and sell it, become rich and famous, retire, become loved in the community, kiss babies ... who am I kidding? Seriously though. What would the ideal phone based logging app look like to you? As for the baby-kissing famous one, let me know when you meet them, I'll stay away. I'm Onno VK6FLAB

Preparation for an outing ...

May 5, 2018 168


Foundations of Amateur Radio Previously I've talked about leaving your shack and setting up your station in a different location. I have my car configured as a mobile shack of sorts, that is, it's got a radio, an antenna mount and wiring to manage the location of the speaker, the head-unit and the microphone. This weekend I'm planning to do a contest and it's been a while since I operated my radio from my car. I've been advocating that you should do some preparation before actually going and doing your thing, so during the week at lunch time I had a look around on the map and picked a spot that I'd like to operate the contest from this weekend. I drove to the location and pretended to set-up my station, actually, I did set it up. Tuned to the actual frequency, configured my tuner, found out that the tuning range for my antenna isn't ideal for 80m, not that this was a surprise. I'm using a so-called multi-tap antenna and the tuning range is somewhat dependent on factors such as the little metal spike that sits on top and where on my car it's mounted. In these situations I've heard other amateurs make statements that it's obvious because it's a compromise antenna. You won't actually hear me say that, since all antennas are a compromise, but then you already knew that. More surprising was the configuration of where I put the head-unit in my car. In the past I've used a modified mobile phone suction mount but sun and age have conspired into making that unsuitable, so I learned that I'd have to figure something out before my contest. Another surprise was that the microphone lead, which connects to a so-called separation cable, think Ethernet cable with RJ45 and joiners which connects back to the radio, had a little broken Ethernet doohicky (it's called the locking latch), which means that while you can push the connector in place, it doesn't stay. I also remembered that this contest was going to be in the dark, so I went looking for my LCD headlamp and it wasn't where I left it. So, now, several days later, after making my to-fix list, I actually managed to cobble together a few spare minutes and address most of my issues. The only one remaining is where to find the Allen Key for an 80m vertical antenna that I'm also bringing, just in case. The point of all this is that normally if you'd asked me if I was ready for my contest this weekend my immediate answer would have been: "Sure". I'm glad I followed the advise I have learned from the many mistakes I've made in the past by actually checking and because I actually went on-site I also managed to check out the local HF environment which means that come contest time I won't have a surprise that could have been managed by better preparation. No doubt there will be more to learn, but that's for after the contest. Perhaps next week. What do you do in preparation for an outing? I'm Onno VK6FLAB

SWR assumptions

Apr 28, 2018 216


Foundations of Amateur Radio In the past I've talked about the Standing Wave Ratio, the SWR, and how it describes some of the characteristics of your antenna system. I say system because it's not just the antenna, it's the connection between your radio and the antenna as well. The coax or feed line, their length and how you've connected your antenna, all feature in the performance of the entire kit and caboodle. As an aside, that's why measuring an antenna with an SWR meter at the bottom of the antenna, while you're bolting it to the top of your mast is likely to give you a different result when compared with the measurement performed at the radio. During the week I was asked about how cutting an antenna changes the SWR. The question included a quote from the ARRL Single-Band Dipoles page which states: "If you see that the SWR is getting lower as you move lower in frequency, your antenna is too long. Trim a couple of inches from each end and try again." The person asking the question, Phil, wanted to know why he was seeing a different behaviour. I've seen the same myself and until I had the benefit of an antenna analyser it also made little sense to me. The reason it makes little sense becomes clear once you realise what assumptions you're working under. When you look for antennas online, or when you buy one, often it comes with a lovely SWR graph. You'll see frequencies on the horizontal axis and SWR on the vertical axis. You'll likely see a lovely mostly horizontal line with a dip downwards at the frequency where you want to use this antenna. The assumption you will almost automatically make, I know I did, for years, was that outside the graph the line continues on its merry way in both directions. That means that you're assuming that the SWR comes down in one place and the rest of the time it's high. If wishing made it so. With the benefit of an antenna analyser you can graph the whole HF spectrum, and depending on the hardware, you might even be able to see VHF and UHF or higher. One thing you'll immediately see is that the SWR is all over the place. It's up, and down, crazy lines, across the whole spectrum. You'll find enormous highs and some very interesting lows along the way. It's one reason why I can use an antenna intended for the 10m band on the 2m band. When you're making an antenna, like a single-band dipole, you might find yourself in a position where your antenna SWR is going up and down like a yo-yo around the frequency where you're wanting to be. The higher the frequency, the more likely that your trimming ends you in a different dip or a different high, outside the one that you're actually looking for. One other comment. The ARRL quote which is talking about HF dipoles states that you should remove a couple of inches from each end. Let's take that literally, two inches from each end, that's 4 inches in total. Let's call it 10cm between friends. If you're trimming a dipole for 160m, you'll change the frequency by just over 1 kHz, but if you're doing this on 6m, then the same trimming will change the frequency by nearly 1 MHz and if you use that HF recommendation for 2m, the change is almost 6 MHz, so, trimming a couple of inches as the ARRL suggests will work for some dipoles on some frequencies, but might get you completely crazy results for other frequencies. Now you know, the SWR isn't high across everything except where you care, it's all over the place and sometimes that helps, and sometimes it doesn't. I'm Onno VK6FLAB

Learning on 2m FM

Apr 21, 2018 232


Foundations of Amateur Radio Last week during F-troop something very interesting happened. If you're not familiar with F-troop, it's a weekly net for new and returning amateurs and every Saturday we welcome callers to the one hour net to discuss anything and everything amateur radio. It's been going for about seven or so years, about as long as I have been making this weekly contribution to the hobby. Normally there's a host, often it's me, but not always, handing the microphone to the next person who then in turn hands the microphone back and the host passes it on to the next caller. This is helpful for new amateurs who then only need to remember two callsigns, their own and that of the host. It's a safe place where people can ask questions and hopefully find an answer, make a mistake, say the wrong callsign, have their roger-beep turned on, be off frequency, all the typical things you do when you're learning or when you've dusted off an old radio after having been away from the hobby for a while. Last week we had a surprise visitor, a special event station, VI4GAMES, operated by Reg VK2MNM who in the midst of the Commonwealth Games was having little success on HF and decided to join in on our net. After saying hello and calling in other stations I started handing the microphone to each caller, encouraging them to make contact with VI4GAMES so they could each claim a contact, end up in the log and get a QSO card for their trouble. Sitting on the side was hard, but at the same time it was extremely rewarding. I witnessed stations calling a special event station for the first time in their life, dealing with strange callsigns, interruptions, distortions and delays, misheard phonetics, incorrect procedures, you name it, I heard it all. There were some who just made the contact and moved on, handing the microphone back to the host and others who started a whole discussion about their life, their station and their joy in making the contact. There were stations just saying their callsign without phonetics, or saying it once, or fast, stomping on the other station, all the things that happen in real life when you're trying to make a contact using HF and SSB. Just to re-iterate, this was on 2m FM, connected via IRLP, Echolink and Allstar to repeaters across the globe, with callers in Australia, New Zealand and the United States. It was eye-opening for me. In the past I've attempted to make contest examples, to make DX contact simulations and tried to get people to change frequency and check back in. As serendipity would have it, this was by far the most learning I've ever seen in the 7 years of this net and I'd encourage anyone to try this at home. Some of the direct take-away tips from this are that using phonetics on 2m FM is not stupid and sometimes it's even required. Repeating your callsign to a new station is not a waste of airtime, since you have no insight whatsoever as to the state of their receiver. You don't know if they have a poor antenna, or if they're connected via the internet, if the link is not optimal or the volume not set correctly. Waiting until the carrier drops on the repeater is a must for many repeaters and keying and talking at the same time is a recipe for being misunderstood. Key your microphone, wait a heartbeat and then start talking. Leaving gaps between overs allows other players onto the field and you should see that as an opportunity, not a burden. I'm sure there were other things that were learned on that random Saturday and who knew that you could learn that much from 2m FM, special event stations and some patience. I'm Onno VK6FLAB

Learning on 2m FM

Apr 21, 2018 232


Foundations of Amateur Radio Last week during F-troop something very interesting happened. If you're not familiar with F-troop, it's a weekly net for new and returning amateurs and every Saturday we welcome callers to the one hour net to discuss anything and everything amateur radio. It's been going for about seven or so years, about as long as I have been making this weekly contribution to the hobby. Normally there's a host, often it's me, but not always, handing the microphone to the next person who then in turn hands the microphone back and the host passes it on to the next caller. This is helpful for new amateurs who then only need to remember two callsigns, their own and that of the host. It's a safe place where people can ask questions and hopefully find an answer, make a mistake, say the wrong callsign, have their roger-beep turned on, be off frequency, all the typical things you do when you're learning or when you've dusted off an old radio after having been away from the hobby for a while. Last week we had a surprise visitor, a special event station, VI4GAMES, operated by Reg VK2MNM who in the midst of the Commonwealth Games was having little success on HF and decided to join in on our net. After saying hello and calling in other stations I started handing the microphone to each caller, encouraging them to make contact with VI4GAMES so they could each claim a contact, end up in the log and get a QSO card for their trouble. Sitting on the side was hard, but at the same time it was extremely rewarding. I witnessed stations calling a special event station for the first time in their life, dealing with strange callsigns, interruptions, distortions and delays, misheard phonetics, incorrect procedures, you name it, I heard it all. There were some who just made the contact and moved on, handing the microphone back to the host and others who started a whole discussion about their life, their station and their joy in making the contact. There were stations just saying their callsign without phonetics, or saying it once, or fast, stomping on the other station, all the things that happen in real life when you're trying to make a contact using HF and SSB. Just to re-iterate, this was on 2m FM, connected via IRLP, Echolink and Allstar to repeaters across the globe, with callers in Australia, New Zealand and the United States. It was eye-opening for me. In the past I've attempted to make contest examples, to make DX contact simulations and tried to get people to change frequency and check back in. As serendipity would have it, this was by far the most learning I've ever seen in the 7 years of this net and I'd encourage anyone to try this at home. Some of the direct take-away tips from this are that using phonetics on 2m FM is not stupid and sometimes it's even required. Repeating your callsign to a new station is not a waste of airtime, since you have no insight whatsoever as to the state of their receiver. You don't know if they have a poor antenna, or if they're connected via the internet, if the link is not optimal or the volume not set correctly. Waiting until the carrier drops on the repeater is a must for many repeaters and keying and talking at the same time is a recipe for being misunderstood. Key your microphone, wait a heartbeat and then start talking. Leaving gaps between overs allows other players onto the field and you should see that as an opportunity, not a burden. I'm sure there were other things that were learned on that random Saturday and who knew that you could learn that much from 2m FM, special event stations and some patience. I'm Onno VK6FLAB

Shakespeare and Coax Stub Filters

Apr 14, 2018 284


Foundations of Amateur Radio If you read it on the Internet, it must be true, but what happens if you read it and there are 700 different answers? In my day job I search countless times a day for answers to problems. Based on my experience I can look at a list of responses to a question and tell myself what the skill-set is of the poster, "they don't know what they're talking about", "they're guessing", "they've got no clue", "they tried it", "ah, this one knows what they're talking about". As an aside, a company once advocated that we should use social media as a way to provide support to customers, but based on my experience, seeing the correct answer in a series of posts being voted down into oblivion and seeing the wrong answer being promoted is a fantastic example of why that won't work, ever. Infinite monkeys with typewriters might eventually write Shakespeare, but it will take an infinite amount of time and before they succeed there will be a whole lot of rubbish. When I started researching magnetic loop antennas several years ago I went through the same process, search for answers online. I found lots of different stories, opinions, measurements, contradictory statements and formulas. I spent some weeks reading everything I could on the subject and after a while a picture started emerging that started to explain to me how a magnetic loop antenna works. I'm no expert, my foray into this died when two ADSL modem transformers died within seconds of me hitting the PTT on my radio and I sort of lost interest. I have a magnetic loop antenna standing behind me, on loan from a friend and I use it to scan the bands. It's compact, easy to tune and one day I'll make more than a single contact on it. All this to say that I've been investigating coax stub filters. If you're not familiar with the notion, you can cut a piece of coax cable to a specific length and connect it with a t-piece to your antenna feed line. If you do that, depending on the length of the coax you cut, you get interesting effects. These effects include filtering, or notching out frequencies, passing other frequencies and all in all affecting what your radio is able to receive and transmit. If you've never set up your radio with some friends nearby for a field day, a contest or a camp-out, you might be surprised to learn that even across the space of a field or a caravan park you'll be able to hear the other station, even if they're not on the same band. You might hear their actual voice, or more likely, you'll hear all manner of overload sounds that essentially show up as noise blocking out the station you're really trying to hear and work. Of course, the reverse is also true. When you're transmitting, your friend is hearing the same horrible gunk coming out of your radio. One of the ways that you can manage this is to set up filters, either notch filters which reduce the strength of undesired transmissions or pass filters which only allow certain frequencies to get to your radio. Combining these will make your life much easier. Coax stub filters are a tried and true method to achieve this and the Internet is full of expert opinion on how to exactly do this. With infinite budget and time, you can try them all out and with your trusty network analyser you can find the combination that works just for you, but in the real world you have a limited amount of coax, money and your lottery winning didn't cover that network analyser. I started this process in earnest two or so weeks ago and frankly I'm no closer now than I was then. I'm still in the reading articles stages. I think I'd like to create two sets of band pass filters and connect each set to a radio. If I'm on 10m, I set my radio to use a 10m band pass and set the other radio to use a pass filter for their band. I figure between the two of them I have something that resembles what I'm looking for. If wishing made it so. To make matters more interesting, I have two rolls of Quad Shield RG6 coax...

Experience comes from doing ...

Apr 7, 2018 208


Foundations of Amateur Radio During the week a friend reminded me that the process of determining what's happening within a shack comes with experience. In my day job my whole skill-set can be summed up with one word: "debugging", in all its many and varied guises, fixing code, hardware, business processes, skill-sets, what ever it may be. The process is pretty much, figure out what's going wrong, find out what shouldn't be happening and attempt to join the mismatch together with anything from gaffer-tape to good old fashioned hard yakka. Back on topic, the question my friend asked was about their WSPR receiver which had stopped making spots. If you're not familiar, WSPR, Weak Signal Propagation Reporter is a way of listening at specific times on specific frequencies for a signal and when received and decoded, publishing the spotted signal on a website. Their first thought was the antenna, that's where the signal comes from, so if that's not working, the rest fails. Pretty good first guess at figuring out what might be wrong. There is an adage somewhere, not sure of the exact wording, but it goes a little like this: if you don't know where to start, start somewhere, anywhere, and go on from there. Based on that the question became: How can I simply test my antenna and should I buy an SWR meter? If you're not familiar with how WSPR actually works, it's a radio receiver connected to a computer running software that decodes the signal and reports it across the Internet to a website that logs reports from around the globe. That sentence hides a level of complexity that boggles the mind if you start digging, but I'll give you a hint, it's not needed in this case. In my own experience with WSPR, my computer would crash regularly and get slower and slower. It turns out that I'd configured it to store a copy of each signal, as an audio file, so the computer drive was chock-a-block full of audio files. End result was crashing. I've also had issues with the WSPR site being unavailable and in Australia we're currently in the middle of rolling out our brand new not so shiny National Broadband Network which in turn causes Internet outages all over the place. While the antenna was a great place to start eliminating issues, there were several other candidates that could also cause issues, none of which required much in the way of effort to eliminate. As a bonus the antenna was also used for a weekly net and a quick scan with a spectrum analyser revealed that it was working just fine. A day later I got a follow-up email, turns out that the station they were listening for, an automatic WSPR beacon nearby had changed frequencies and that meant that it wasn't being received. One plus One equals Three. So, the lesson in all this is that two minds are better than one and that you can both be wrong at the same time. One thing I really love about amateur radio is that the problem domain is huge. You can think of amateur radio as two stations talking to each other, or you can imagine a place where there is so much variability that exploration in and of itself is the activity. Now that I've moved, I should fire up my WSPR receiver and see what gives. Which reminds me, what WSPR spots have you seen and if you're allowed to transmit WSPR with your license, how far have you been heard? I'm Onno VK6FLAB

eBook Volume 6 - short

Apr 3, 2018 26


Foundations of Amateur Radio is now available as an eBook. In Volume 6 - Joy of discovery - read about microphone technique, the dead band, propagation maps, melting coax, amateur radio satellites, strange antennas, self-training, SOTA adventures and more. Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside. I'm Onno VK6FLAB

You and the IARU

Mar 31, 2018 231


Foundations of Amateur Radio Have you ever considered the infrastructure that exists to make it possible to tune to 7.090 MHz, call CQ and make contact with anyone on the planet? In a world where we as radio amateurs share spectrum with radio and television broadcasters, mobile phones, wireless networks, satellites, GPS, drones, wireless headphones, radar, boating, aviation, citizen band, garage door openers, fitness trackers and any other wireless gadget imaginable, not to mention radio astronomy, microwave ovens, meteorological aids, inter and intra car communication, autonomous cars, trains and more. The world clamours for spectrum and in among those allocations we find the amateur bands. There are 24 million odd people in Australia, a few normal people, but mostly odd and about 14000 radio amateur license holders, that's about 0.06% of the population. It's extraordinary that in the last 100 years of radio spectrum allocation we have access to the bands we have. It's easy to forget that in the rarefied air of amateur radio where we have access to an astonishing amount of spectrum how unique we really are. Not only do we have a situation where we have access to bands, this is mostly global access. There are exceptions and while bands don't exactly line up, for example 7.090 MHz in Australia and the UK is an SSB calling frequency, but in the United States this is a CW, RTTY and data frequency, still amateur radio, but not the same mode. How this allocation exists is a combination of being the first mover, that is, radio amateurs came along and used it before anyone else had any use for the spectrum and the existence of the International Amateur Radio Union, the IARU. The IARU is a topic in and of itself, but in essence it's an organisation that exists and has done since 1925 due to radio amateurs combining their efforts. The IARU consists of over 160 member countries which are represented by their peak body, in Australia the WIA, the UK has the RSGB and the US has the ARRL. So, if you're a member of one of those organisations, you in turn are represented at the IARU where volunteers represent you and me on the world stage. The IARU has organised the world into three regions that correspond with the International Telecommunications Union, Region 1 is Europe, Africa, the Middle East and Russia, Region 2 is the Americas, Region 3 is the rest, Asia and the Pacific, that includes India and China. At some level discussion about the IARU, the role it plays and the processes it has and services it offers is a dry and boring administrative slog. It's not sexy, it's not thrilling, but every once in a while I think it would be a great idea to consider what the world might look like without the IARU and what our hobby might look like had this organisation not existed. There are some public activities that the IARU engages in, the Beacon Project, the HF World Championships and the Worked All Continents award. There's the Monitoring System and other activities such as the Amateur Radio Direction Finding or ARDF championships. The public relations face aside, much of the activity of the IARU is invisible, going to meetings, making proposals, keeping abreast of new technology and threats to radio spectrum, participating in working and study groups and the administration of all this volunteer effort. Next time you call CQ and a station on the other side of the planet answers, consider some of the invisible forces at work that make it possible. I'm Onno VK6FLAB

Coax Loss vs Connector Loss - now with more coax

Mar 24, 2018 241


Foundations of Amateur Radio Recently I spent some time discussing the losses associated with connectors between your radio and your antenna. The traditional wisdom, and I use the word "wisdom" ironically, says that each connector introduces loss into the feed line. There is an understanding that the more connectors you have the worse it is and the more loss you have. Jim W6LG did the test, connected up 30 odd connectors and measured. His measurements were done on 14 MHz and on 50 MHz, using 50 microvolts and 1 kilowatt. No discernible difference. Of course after I mentioned this out loud the questions started. Why didn't he test this at a usable frequency, something like 145 MHz, or in the GHz band? Then there were those who said that this wasn't a real test and that it should be tested with coax in between the connectors. I discussed this all at some length and one idea we had was that perhaps the intersection between the coax and the connector was the problem, that each transition between coax and connector and back was introducing the loss. I wondered if there was a way to test this. Turns out that somebody already did. Back in July 2015 Jim K9YC decided that this needed to be tested. That's right, another Jim. He set up a test with a dozen 100 foot lengths of low loss coax, that's just over 365m of coax. This included two dozen PL259 connectors and 11 barrel connectors. He tested using a calibrated HP generator/voltmeter rig. The total loss was and I quote: "one dB or so less than the loss specified for the cable by the manufacturer". So, the run with connectors was actually better than a single run of coax. In case you're wondering, he tested this up to 500 MHz. Jim K9YC points out that there is a grain of truth in the loss when using junk connectors which can introduce excessive loss and can overheat because the centre conductor is too small. I should mention that this might now debunk the connectors and loss issue, at least up to 500 MHz, but there is something to be said about reducing the number of failure points along the way. Having 35 connections instead of two is an added risk of water ingress, loose connections, short circuits in the connector and potential for other unexpected things like an intermittent connection. In the broader scheme of things, on a field day, or a temporary antenna set up, there's clearly nothing wrong with using some connectors to join together some coax. It also means that my investment into coax terminated SO239 connectors was based on poor information, though it does mean that I don't need to carry nearly as many barrel connectors around. Perhaps it's time to, as Jim puts it, put this "old wives' tale" to bed. In the same document Jim discusses many other questions in relation to coax and stub filters in your HF station. I came across the document while I was looking for information about coax stub filters, since I just participated in another contest where two stations in the same location were interfering with each other and I want to be prepared for next time. There's a lot to discuss in relation to coax stub filters, but in essence you create a quarter wave and half wave lengths of coax that are resonant at a range of different frequencies and the combination of these will either pass or block the band you care about. Given that I have a roll of Quad Shield RG6 lying around, I thought I'd try my hand at making a set of these for my next outing. No doubt I'll share my adventures with you as I explore and dig through the pile of information. Coax and connectors, stubs and filters, it's all in a days experimentation in this amazing hobby we call amateur radio. I'm Onno VK6FLAB

eBook Volume 5 - short

Mar 20, 2018 28


Foundations of Amateur Radio is now available as an eBook. In Volume 5 - Getting on air - read about the perfect SWR, how to become a better operator, what batteries to use, the difference between a propagation forecast and reality, the phonetic alphabet, antenna compromises, Q-codes and more. Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside. I'm Onno VK6FLAB

Coax Loss vs Connector Loss

Mar 17, 2018 182


Foundations of Amateur Radio A question that comes up regularly is one about loss, specifically loss in the coax and connectors between your radio and your antenna. The general wisdom is that better coax gives you better results and more connectors is bad. Anything with double joiners, or such like is really bad. So, essentially we've been taught that we should have the shortest coax possible with as few connectors as possible. Pretty fair and reasonable, right? During the week I was introduced to a video made by Jim W6LG. Jim has a YouTube channel going back a couple of years with about a 100 videos. One video is loosely called Jim measures the loss in coax connectors and 100 foot of RG8X. In case you're wondering, 100 foot is 30m and 48cm of coax. I know this because the United States of America despite appearances to the contrary is actually metric, they defined the inch as being 2.54cm back in February of 1964. Other than driving on the wrong side of the road, they're not too strange and they talk on the air, a lot, so there's that. Back to Jim. He rummaged through his bits box, the one you have, the one that every amateur has, and if you don't then you clearly need to spend some time being with an Elmer and learning the ropes. Jim pulled out 30 odd connectors, SO239 and PL259 by the looks of things and daisy chained them all together. Jim has been around the block a few times and he has connectors going back to World War 2, so he really did find the bottom of his box to make his video. Anyway, he rigged up a testing tool to compare a single connector to 30 connectors. Measuring the difference, showing pretty graphs, lines and scales, the whole bit. He even compared 20m to 6m and tested both extensively and even re-did the tests with a kilowatt. Then as icing on the cake, you know the one, with a cherry on top, whipped cream on the side, he did the same test with the 30 odd meters of RG8X coax. I could leave you hanging here and let you go and find Jim's video, but that wouldn't be fair if you're currently in the middle of your commute to work like several people I know, so I'll share the outcome, but if you get the chance, the 5 minutes of your life that you'll spend with Jim are worth every second. So, what was the outcome of Jim's test you ask? Surprisingly, there was no discernible difference between one connector and 30 connectors in-line, not at 14 MHz, not at 50 MHz, not at 50 microvolts and not at 1 kilowatt, about 223 and a half million microvolts. Using RG8X coax, which sits about halfway between RG58 and RG213 in terms off loss, there was however 22% loss at 14 MHz and 40% at 50 MHz. Does make me wonder if it's the coax manufacturers who have been telling us to buy more coax rather than join two bits of coax together with a connector. Might have to do that test myself. Better go and start digging through my bits box. I'm Onno VK6FLAB

Amateur Radio Minimalism

Mar 10, 2018 154


Foundations of Amateur Radio The ultimate radio shack is a nirvana that most amateurs I've met strive for all their life. One of the many views I've heard on the topic keeps speaking to me, one of minimalism, less is more, what is the absolute minimum that you can use and still call yourself an amateur? As you know, I've recently moved and my shack was packed up into some boxes and is now slowly being unearthed. At the moment there are two antennas, a radio and a power supply. Keen observers will note that this is the same as it was last week. I've left well enough alone because of two reasons, one being that I'm trying to catch up on lost work during the move and the time where my internet connection was less than optimal, the other reason being that I've been attempting to work out what I actually want from my shack. Unlike my previous QTH, my current location affords me more flexibility, much more, as in four to six times more space to call my own. That's not to say that I was previously living in a shoebox and now I'm in a mansion, just that the distribution of space this time around is working out very well. So, I could go crazy, install computers, screens, multiple radios, a work bench, a soldering station, a weather monitoring station, a contest computer and the likes, or I could spend some time enjoying the breathing space around me and contemplate what I should do with this new found freedom. Initially I pictured setting up a dedicated DX cluster screen, a propagation screen, write some scripts to show the current maps using something like a raspberry pi, set up a dedicated space for doing contests and figure out how to mount several HF antennas, but the more I think about this, the more I wonder if this is what I really want. I've said many times that I adore contesting, it's a pull, a challenge, a bridge I have to cross, a mountain to climb, whatever the metaphor you see, but is that all there is about amateur radio that I enjoy? I know that I'm working on several bits of software, another DX project, some research and other activities, all related to amateur radio, but not specifically contesting. The thing I'd like to attempt to avoid, perhaps foolishly, given my less than latent hoarding tendencies, is the clutter that I see in other shacks. They're perfectly homely places, comfortable, full of interesting things, but I'm wondering what a minimalist shack might be instead, think of it as a "tiny houses" equivalent of getting rid of clutter in my life. What minimalist successes and failures can you share that helped you along the way? I'm Onno VK6FLAB

eBook Volume 4 - short

Mar 6, 2018 30


Foundations of Amateur Radio is now available as an eBook. In Volume 4 - Just get started - follow my journey through the amateur radio community, how to use QSL cards, mobile antennas on HF, licensing requirements, policing the airwaves, the super check partial list, packing up coax, lightning protection and more. Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside. I'm Onno VK6FLAB

What improbable antenna solution works?

Mar 4, 2018 256


Foundations of Amateur Radio There is some truth in simplicity. I've mentioned in the past that "suck it and see" is a perfectly valid solution to figuring out if something is going to work or not. I've moved into my new home, my new QTH. The roof is colour bond, that's basically a corrugated iron roof, painted in some random colour. I think it's grey, but don't quote me on that, could be green. Inside is a mezzanine floor, essentially carving out a space within the roof area. It's going to be my office and radio shack, so after setting up technology, I had a spare 15 minutes and came across a box that had my radio bits inside it. After setting up power I went and combed through some more crates to locate a magnetic mount and the vertical I use on 2m and 70cm in my car. The roof beam is held up by a steel post which forms part of the railing that surrounds the mezzanine floor. All conventional wisdom tells me that this is a poor place for an antenna. So, undeterred with little else in the way of simple options, I stuck my magnetic mount to the steel post with my vertical attached. Of course this doesn't mean that I have my vertical actually mounted vertically, in fact it's not, it's horizontal. So, there's one of two steel posts that holds up the steel roof, a magnetic mount stuck to the side of the post with a vertical, running horizontally. It keyed up the local repeater the first time. Made some contacts, spoke to three local amateurs to confirm that they could in fact hear me, swapped sides on the post, from parallel to the roof line to 90 degrees off the side with some improvement. Now as I said, on paper this shouldn't work. The roof beam runs north-south, the repeater is off to the east of the pitched roof, so the signal isn't making its way off the ends, it's going through the roof, or I've managed to use the roof post as an antenna, or the roof, or both, or the signal is bouncing down, over a metal fence, who knows. The point is, it works when anyone you'd have asked about this would have rightly told you that it won't. When I asked recently what the ideal shack should look like, one person who travelled a lot pointed out that just enough shack is a good place to start. Right now, I'm a power supply, radio and a horizontally mounted vertical into the minimal shack. I was asked if I'd tested HF yet. Seriously, the radio is 15 minutes out of the box. But in a word, yes. I put on a 10m vertical, also mounted horizontally, same magnetic mount and I can hear the local beacon on 10m, 12m and 15m, a vast improvement on my previous HF experiences at home. Overall the noise on the bands seems less than it was in my old house - this could be because of shielding of the roof, or it could just be less actual noise, or because my antenna is mounted horizontally. Previously I had S9 noise, now it peaks at S5, but on average it's around S2-3. This is not a proper test by any stretch of my imagination and while initial indicators are better, this is by no means a definitive test of the HF band. For my next trick I'll be taking a closer look at the railing that surrounds my office, It's made from stainless steel stranded wire, the stuff you find on a boat, with seven strands to choose from, in three separate orientations, so plenty of room for experimentation and more if I dare to use the strands on the staircase, seriously, I won't be. One thing I will do before I start keying up for the next HF contact is do some electro magnetic radiation research to learn if I'm in the danger zone, or if my family might be exposed to unsafe levels of RF radiation. Normally this isn't an issue with 5 watts when the antenna is on a roof, but now I have it indoors I'll spend some time making sure. I still have a magnetic loop on loan from a friend, packed away in a box that I'll unearth in the next couple of days to see what it has to say about the new RF environment. As I said this is just the beginning and I've not yet been...

What criteria do you have for your ideal shack?

Feb 25, 2018 248


Foundations of Amateur Radio From time-to-time people move and their shack tends to move with them. For me that move is happening right now, I'm moving all of 900m up the road, a long story in itself, but perhaps best told over a camp fire far from civilisation. As I started the process of working out what needed to be done I realised that I made a few rookie errors. The first one, one that I've made before, but at the time my excuse was that I knew nothing about amateur radio - some say I still don't - this time I was busy focussing on above ground power, pole-top transformers and high-speed internet. I forgot to check mobile phone coverage, forgot to bring a radio and forgot to listen on HF. I will no doubt find out what the state of these things is when I actually move, in a few days from now, but my rationalisation was essentially, "I'm not able to operate from home as it is, so it won't get any worse and if I'm lucky, it might get better." Frankly I didn't have the heart to tell my long-suffering partner that there was yet another condition, you know among the "must have actual proper internet, not the promise of one next year", "must have space for my office" and "a place that can be locked up in the garage". I skipped the "must be amateur radio friendly" tick box for familial peace, and as I said, it cannot get worse and it might get better. Looking around my office now, it occurs to me that I'm going to have to remove the coax that runs through the window, which involves either cutting the coax, or de-soldering the connector. I suspect that it will become the most expedient of the two, given that de-soldering involves having to find my soldering iron among the half-packed-up house, cutting looks like it. I'll tell myself that it's good because I'll find out if my coax is waterlogged, but between you and me, it's because I'm impatient to get moving. The remaining part of this is the thing that's on the other end of the coax, the metal shiny thing on the roof, known to most of the amateur community as a 10m vertical, a metal rod, resonant on the 10m band, about 2m long, clamped to the gable of my pergola, will have to come down. Of course at that point I'll be off the air. No counting how long that will last, but I'm hopeful that a quick-and-dirty magnetic mount will get me up and running shortly after the move. Of course in an ideal world I'd already have measured out the future radio-shack, have a room away from the house, insulated, away from the fence-line, lots of backyard with a choice selection of high trees, no noisy neighbours, council regulations that encourage radio amateurs and a coffee machine, a bed and while I'm at it, air conditioning. Who am I kidding? I'll likely be able to put my radio somewhere in a corner on my desk, much like it is right now and if I'm lucky, I'll be able to be on-air without disturbing the family. This all in stark contrast with a friend of mine who asked the community a simple question. Where would you put your radio shack if you needed fast internet and nearby medical services, anywhere in the state. The answers were many and varied, from ludicrous to amazing, from off the cuff to well researched, just waiting for the win on the weekend lottery to be able to pay for it. Our shack is an integral part of our hobby and while I see some amateurs go out of their way to find and position their ideal shack, I see many more just making do with what they have. No doubt there is a balance to be found. I'm curious to hear what criteria do you have for your shack? What things are essential and what would be nice to have. If money wasn't a problem, what would your ideal shack look like and where would it be? I'm Onno VK6FLAB

eBook Volume 3 - short

Feb 21, 2018 26


Foundations of Amateur Radio is now available as an eBook. In Volume 3 - Share the fun - follow the third year of my journey, how to make contacts on HF, how to go on-air QRP, propagation planning, how to deal with trolls, online resources and more. Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside. I'm Onno VK6FLAB

What do you know now that you would have liked to have known when you started in amateur radio?

Feb 18, 2018 232


Foundations of Amateur Radio Recently I was asked: "What do you know now that you would have liked to have known when you started in amateur radio?" The hobby of amateur radio is one filled with generosity. Extreme forms of it. People go out of their way to help, to explain, to loan equipment, to help out, to repair stuff and to participate. In the past I've spoken about the negative aspects of this hobby as well. Belligerence, the warlike aggressively hostile nature of individuals and groups in amateur radio is like nothing I've ever encountered elsewhere, and it needs to be acknowledged. In many ways amateur radio is about extremes, generosity against belligerence, very polarising, confusing and challenging. That said, amateur radio is a hobby like no other. It sits in a field of exploration, of discovery, of invention, challenge and experimentation. Amateur radio navigates between scientific and empirical learning. It's regulated to encourage research and at the same time encourages new entrants into the field with a weekend course. The range between learner and professional embodies the amateur radio community. One of the things that caught me by surprise about amateur radio is that nothing is set in stone. You would think with a field based around physics that would not be the case, but given the vast range of variables at play, often "suck it and see" is a perfectly valid way of finding out if something works. I'd hazard a guess that the most frustrating part of asking a question as a new amateur is the answer: "Try it and find out." In 1920 H.L. Mencken said: "there is always a well-known solution to every human problem - neat, plausible, and wrong". With that in mind be sceptical if an amateur gives you the definitive answer on how to do something. Often the number of variables is infinite and your situation is subtly different from theirs. In that context, the answer "Try it and find out." is perfectly valid, frustrating as it is. I started in this hobby just over seven years ago and since then I've continued to collect what I think of as puzzle pieces, bits of information that I carry around. For example, a dit is the letter e because it's the most common letter in the English language. Voltage equals current times resistance. You need a carrier to measure the standing wave ratio. Remember to bring the head unit connecting cable when you go into the field. There are thousands of bits of information like that floating in my head. When two collide, I gain some knowledge. The most recent example of that was my explanation on how you could use the offset within a side-band signal to determine if a radio was on the correct frequency. It took a while for me to understand it enough to explain it and when I could, I did. For example, right now I'm working through the various types of decibel. You might have thought of a decibel as a particular unit, but actually there is more than one. The deeper you dig, the more crazy it gets. For example, the definition of a decibel in relation to sound appears to exist within an ISO standard, but you can't get that standard unless you buy it. Seriously, a physical standard that you have to buy in order to know what it is. Another example is the definition of the Ampere, which involves infinite length wire and the force between them. The mind goes cross-eyed thinking about how to calibrate an ammeter. So, to answer the question: "What do you know now that you would have liked to have known when you started in amateur radio?" It's complicated. It's challenging and it's like nothing else. Find your own way, talk to people, ask questions and be prepared to be amazed and annoyed at the same time. One final comment, amateur radio has its share of "Mostly Harmless" crocodiles, all mouth and no ears, but the overall apt description that comes to mind to describe this fascinating community is "generous and welcoming". I'm Onno VK6FLAB

How should I promote my contest?

Feb 11, 2018 355


Foundations of Amateur Radio The act of telling someone about something is promoting it, not in a marketing sense, just an awareness sense. The act of not telling someone is keeping a secret. Radio amateurs, and I have no doubt, people who are not, like to plan things. They set-up contests, on-air activities, organise swap-meets, build websites, write articles, invent things, build stuff, and all manner of other amazing activities. Some amateurs talk about what they've been up to, but most just sit quietly, hoping that their brilliance will be discovered by someone. Of course that rarely happens. Let's imagine a contest. It's an activity that you'd ideally want other amateurs to participate in, talking to yourself, on your own is like being a broadcaster and I can tell you, that's a tough gig. A contest is about making contacts between different participating people. So, your contest, it's going to have rules, a planned outcome, say more QRP activity on 40m, and it's going to run at a particular time. I've lost count of the times where that's the sum-total of effort put into organising a contest. Of course the contest flops, since no-one knew about it, and often that's the end of it. So, what can you do to actually get a head start in making this contest work? For starters, you should figure out who the audience for this contest is. If you set it up on 160m and aim for beginners you'll have a problem, since they're not allowed on that band. So, the audience is based on the rules of the contest and of course one influences the other. Once you've got a defined audience, and no, all the amateurs on the planet is not a valid audience, since by that metric you could also say all the taxi-drivers in New York city, and while that is a defined group, it's unlikely that you'll find much in the way of participation in your amateur radio contest. That's not to say that there isn't a New York cabbie who isn't also an amateur - hi - but their amateur status is not the same as their taxi-driver status, so pick an actual defined audience. The more defined, the better. Let's say for a moment that your audience is amateurs who've been in the hobby less than a year who live within 1000 km of you. Now your task is to figure out how you're going to talk to them, what you're going to say and how you're going to encourage them to be part of this wonderful contest. You could target the local amateur schools, and ask them to send out an email on your behalf to promote your contest, or you could approach the local radio clubs and ask them to promote your thing to their new members. You could seek out local radio nets that cater for new amateurs, you could write articles for the local radio magazine, or you could post comments on your favourite social media outlet. None of these things are particularly difficult, onerous or complex, but not doing them means that your contest is doomed before it starts. So, now you have an audience and some outlets for communication. What do you say? I've seen contest promotions that list the frequencies and link to the rules. That's it. Not very inspiring. I've seen promotions that state that they're aimed at a particular audience, but the rules indicate that you'll need to have a particular license in order to participate because the bands or modes exclude the audience. All these messages achieve is the opposite of promotion. People know to avoid this contest, rather than feel inspiration to participate. So what should your message be? First of all, it should be written one-on-one. You're listening to me right now. The fact that there are other people also listening is not relevant to you. Every communication is like this. Everyone experiences communication as a message to themselves, to their needs, emotions, desires, motivation, just me and you, talking. Of course there are messages intended for a stage, but this is not one of them. We're not in Wembley stadium and I'm not on stage encouraging...

eBook Volume 2 - short

Feb 7, 2018 28


Foundations of Amateur Radio is now available as an eBook. In Volume 2 - Find the spark - follow the second year of my journey through the hobby of amateur radio, what's the point of Morse code, making contacts during lunch, Magnetic Loop Antennas, keeping your shack tidy, the identity of your callsign and more. Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside. I'm Onno VK6FLAB

Antenna gain and polar chart magic

Feb 4, 2018 320


Foundations of Amateur Radio If you've ever been on the hunt for an antenna, and let's face it, in amateur radio that's pretty likely, you'll get information about the gain of an antenna. Often someone will tell you that this one has 12 dB gain, versus that one which only has 9 dB. As an aside, I've seen a few videos where people are comparing sound levels and mention that without the fan, there is only 3 dB less noise. What they don't realise is that 3 dB means HALF the noise. The same is true with an antenna. That 9 dB antenna has half the gain of a 12 dB antenna. In the past I've talked about gain. It's always in comparison to something else. If I say "that antenna has 12 dB gain", I'm actually saying: "that antenna has 12 dB gain when compared with an isotropic source". To jog your memory, an isotropic source is a theoretical source of electromagnetic radiation. It cannot actually exist. It radiates uniformly in all directions. Now when we talk about gain, we're saying that our new funky antenna radiates better in some or other direction than an isotropic source. As a consequence of this, it also means that it radiates worse in other directions. So antenna gain is a trade-off between radiating everywhere like an isotropic source, and only radiating in one direction like a laser beam. As an aside, a laser beam could be seen as an antenna for light. It radiates much better in one direction than in any other, and given that light is also an electromagnetic radiation, we're still playing in the same area of physics. If you've ever shone a torch light onto a wall, you'll have noticed that the light isn't uniform. There are brighter and darker areas. It's the equivalent of differences in gain. Some bits of the light are amplified more than other bits. If you compare it to something like a candle, not exactly an isotropic source, but remarkably close, you'll notice that the light is uniform. A torch doesn't shine from the rear, the energy from the light that's missing from the rear comes out the front and that's gain. Radio antennas do the same thing. In order to compare antennas with each other we've devised several tools, the most common is a polar plot. It's a circle that is divided into 360 degrees, and inside the circle are concentric circles with gain numbers attached to them. Often, but not always, the outside circle has 0 dB as a value and you'll see -10 dB, -20 dB and so-on as you get closer to the middle. Weaker signal is drawn away from the outer edge, stronger towards the edge. No signal in the middle. As you walk around your torch, you could record the strength of the light. Where it's strongest you'd make a mark on the edge of the chart. Where it's weakest you'd mark towards the centre of the chart. If you were to take your torch and take a slice through the middle of your battery, through the reflector, through the globe, through the lens and out to the wall, you'd end up with what a polar chart is displaying. Of course you can slice through your torch in any direction and make a chart, but traditionally, you'd slice it horizontally and vertically, or azimuth and elevation - and if you can't remember which one is which, an elevator goes up. A torch is generally symmetric, so both charts should be the same, unless your reflector is a weird shape at which point the two charts will likely be different. Antenna charts work the same way. The polar graph is showing the signal strength as you walk around the antenna - twice - once for the horizontal slice and once for the vertical one. As I said, the outer edge of the chart is set at 0 dB. This is because you need to compare full signal to less signal. If you are comparing multiple antennas and they all have the same 0 point, you can draw them over the top of each other and see their differences. This allows you to compare wildly different antennas with vastly different amounts of gain. I must also point out that you can get more signal strength in...

Just enough radio ...

Jan 28, 2018 199


Foundations of Amateur Radio In the past little while you've heard me talk about WSPR, Weak Signal Propagation Reporter and I've told you about signals I've heard across the planet. The longest distance at the time was a HF report, 18656 km from Perth to Pennsylvania, very nice indeed. I switched to monitoring 6m, 2m and 70cm about a month or so ago. My reports had been pretty minimal, from my QTH to the suburb next-door and then two suburbs away. Proof that a station is working, but hardly anything to celebrate or even mention. The other day I came across a report a little further away, Perth to Adelaide, 2142 km away. Not world record beating, or even earth shattering, but proof that 6m propagation does have its moments now and then. Then a surprise contact, Perth to The Rock, not the one in the middle, or the one with the wave, the one on the Olympic Highway between Wagga Wagga and Albury, 2899 km away with 20 Watts on 6m. My reports aren't particularly far or amazing. You might recall Wally VK6YS who made a contact on 6m between Perth and Israel. He'd been at it for a little while, longer than I've been an amateur, but not quite as long as I've been the apple in the eye of my mother. 38 years it took for Wally to make that contact. So why am I making any mention of my little achievement? Simple really, my station and Wally's station are nothing alike. He had a large beam on 6m located on a property with few noise sources and his patience paid off. My station consists of a 10m antenna, that is, it's not 10m tall, it's resonant on 10m, and happens to also manage 2m. I've not actually checked to see what 6m on this antenna looks like, perhaps a project for another day, but it sits there, clamped to a metal pergola at the peak of a corrugated iron roof and connected via 20m or so of RG58 coax, cheap RG58 coax, connected to my radio that I use to host F-troop most weeks. I have to restart my WSPR node monitoring software several times a week since the Windows XP notepad computer it's running on crashes regularly. I have to remember to open the squelch when I finish F-troop and connect the WSPR node back up and I have to make sure that there's enough empty disk-space to make sure that I can actually log stuff. This isn't a sob-sob story, woe is me, my station isn't a massive station. It's more about that you can achieve these kinds of things with small and minimal resources. One of my friends is doing really well with a USB TV dongle decoding WSPR on a Raspberry Pi, others are using thousands of dollars of gear and everything in between. The point is that you too can get started without massive expense. A simple radio, something to run WSPR, which can be a Raspberry Pi, an antenna of sorts and you're on the way to check out what propagation is like around your QTH in your neck of the woods. Amateur radio doesn't have to be expensive, it doesn't have to be extensive, it doesn't even have to be elaborate, it can just be enough. I'm Onno VK6FLAB

eBook Volume 1 - short

Jan 24, 2018 28


Foundations of Amateur Radio is now available as an eBook. In Volume 1 - Join the hobby - follow my initial journey through the community, what to buy when you start, how to participate in the community, things to practice, what the first steps look like once you have a license, playing in radio contests, encouragement and sharing. Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside. I'm Onno VK6FLAB

Virtual Radio

Jan 21, 2018 221


Foundations of Amateur Radio There is a feeling of anticipation in the air, the year has started, there are so many different ideas bubbling through my mind that I feel like an excited puppy dog wagging its tail. I've been playing with a wonderful piece of software called GNU Radio, more on that in a moment. So, I have for a while been dissatisfied with the offerings of SDR software. There is lots of development going on, lots of new toys being invented and many different hives of activity in this area. It's not unlike the progression from reel-to-reel based radio broadcasting via VHS tape, to computers with audio files. There are lots of solutions solving specific problems, but there are also a group of solutions looking for a problem and only time will sift out which one is worth the effort. In amateur radio we deal with valves, resistors, capacitors, inductors, transistors, integrated circuits, crystals, connectors, solder and many, many different physical things. I'm a computer guy, have been since I was in primary school. I grok computers, more-so than any aspect of anything else. Amateur radio was intended as an escape from this world, but initially to my dismay, but now to my delight, computers are making serious inroads into the hobby. Not just as peripherals that take care of logging, messaging, propagation forecasting and the like, but as integral parts of the radio. I looked at GNU Radio several years ago and wasn't able to understand what it did and how it worked. I didn't have enough in the way of radio skills or vocabulary to get started, but in learning about my hobby I now have a much better understanding. GNU Radio is a tool, a piece of open source software, that allows you to build circuits inside a computer that process information. Not unlike how filters, amplifiers and oscillators do this inside a physical radio. If you want to change the behaviour of a radio, you need to alter a circuit by changing components, or re-design the circuit entirely and re-build it. Hours of planning, soldering, testing and the like, just on a hunch or an idea. It's how we've been doing development for centuries. GNU Radio allows you to tweak a radio on the spot, in real-time, and see what it does. The feedback loop is immediate. You build up a sequence of blocks, an oscillator, a filter, a combiner, splitter, decoder, spectrogram, waterfall, whatever and if you need it do do something else, you either swap out one of the blocks, or change one or more parameters, better still, replace a fixed parameter with a slider so you can change it while it's running to see what happens. For example, displaying a Lissajous figure in the real world involves two signal generators, cables, an oscilloscope, power, gain settings, timing, several hundred, if not thousand dollars worth of gear. In GNU Radio it involves two signal source blocks and an oscilloscope block, joined together. All there, three blocks, two lines and it's working. Making an FM receiver in GNU Radio involves a source of radio frequency information, say a $20 RTL-TV dongle and an FM decoder block. You can display it on a waterfall with a third block, or listen to it with an audio block. To make matters even more interesting, you can build your own blocks, transmit if your radio is capable and test all of this without ever needing to go to the local electronics store or heat up a soldering iron. I have no doubt that this changes amateur radio for me and I'm fairly sure it will do the same for you. I'm Onno VK6FLAB

eBook Volume 6

Jan 17, 2018 45


Foundations of Amateur Radio is now available as an eBook. Six years in the making, after much prodding from fellow amateurs, the edited transcripts of this podcast are now available as a series of eBook volumes. Covering our amazing hobby with short discussions about hundreds of different topics. In Volume 6 - Joy of discovery - read about microphone technique, the dead band, propagation maps, melting coax, amateur radio satellites, strange antennas, self-training, SOTA adventures and more. Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside. Amateur radio is a thousand hobbies rolled into one. I hope you find your way. I'm Onno VK6FLAB

Building a better community?

Jan 14, 2018 197


Foundations of Amateur Radio A week or so ago I watched a movie that was simultaneously the funniest and saddest movie I'd seen in a while. "Pecking Order". It follows members of the Christchurch Poultry, Bantam and Pigeon Club in the lead up to the New Zealand National Championships, as they battle history and each other in a quest for glory and for the love of their birds. Think "Best in Show" with Chickens. While watching, all I could see was squabbling radio amateurs. We're having a similar situation in the Wireless Institute of Australia. There is evidence of gross financial mismanagement, claims and counter claims, Directors with an axe to grind, lawsuits and feathers in the mail. I understand that the Radio Society of Great Britain went through similar disruption several years ago. The ARRL is also going through upheaval right now. Rules, conduct unbecoming, expulsions and gag-orders abound. All these experiences deal with how a board conducts itself, how individual members react and how the main membership just wants to get on with things. Today I read an article in CQ Magazine, titled "We Have Met the Enemy ... and He Is Us". It leads me to wonder, what is it about being on a board that causes you to become entitled? What is it about being a radio amateur that makes you feel entitled to belittle and ignore those around you? What is it about our community that is toxic and detrimental to its survival? No doubt as I become older and perhaps wiser I'll get personal insight into these attributes when some young turk comes along and puts me firmly in my place, but for now, I'm the young turk, and you can keep your quinquagenarian jokes to yourself. I've heard it said that if an organisation is eating itself, let it die. There is something to be said for that sentiment. It causes new structures to be formed, new processes to be created, new ideas to propagate and new people to participate. The thing is, doing this also kills off history, it kills off a knowledge base, it destroys lives, it makes for loss of productivity, loss of investment and it is just plain bad for business. When I was growing up I was told of an organisation that would split its territory in half and form two new organisations once it hit 20 or so employees. Each new organisation would carry on, splitting in half as it grew. The idea was that if you had more people than that inside a company it became unwieldy. I don't know what's become of that organisation, what it's called, or even if it even still exists. I'm using it as an example of new thinking, a new way of trying to build an organisation, a new approach. What kinds of new approaches could we come up with for our representative bodies in amateur radio? For that matter, what new approaches could we imagine for ourselves and our community? There is a very powerful quote by Margaret Mead: "Never doubt that a small group of thoughtful, committed, organised citizens can change the world; indeed, it's the only thing that ever has." I'm Onno VK6FLAB

eBook Volume 5

Jan 10, 2018 46


Foundations of Amateur Radio is now available as an eBook. Six years in the making, after much prodding from fellow amateurs, the edited transcripts of this podcast are now available as a series of eBook volumes. Covering our amazing hobby with short discussions about hundreds of different topics. In Volume 5 - Getting on air - read about the perfect SWR, how to become a better operator, what batteries to use, the difference between a propagation forecast and reality, the phonetic alphabet, antenna compromises, Q-codes and more. Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside. Amateur radio is a thousand hobbies rolled into one. I hope you find your way. I'm Onno VK6FLAB

What is amateur radio?

Jan 7, 2018 206


Foundations of Amateur Radio What is amateur radio? What's not part of the hobby and what is? The more you dig into this, the deeper the rabbit hole goes. I'll start with an analogy to set the scene. In aviation, Sir George Cayley was the first person to investigate heavier-than-air flying vehicles. He invented the aeroplane in 1799. The first full-sized glider, built in 1849 carried the first person in history to fly, the ten-year-old son of one of his servants. Since then the Wright brothers made their flight at Kitty Hawk. We saw the invention of commercial aviation, the turbo prop, the jet engine, the space-shuttle, helicopters, drones, rockets, hot-air balloons, the Hindenburg, the Goodyear blimps, hang-gliders, gyro-copters and many, many other contraptions. Each of those are considered aviation and the person controlling the device is considered a pilot. In amateur radio we talk on the radio. We also create repeaters and talk on them. We link them together using what ever technology is available. We make it possible to connect to such networks using software such as Echolink, AllStar Link, IRLP and other internet based systems. We create digital networks with DMR, use WSPR to exchange information, make contacts using CODEC2, have contests using CW and Morse code. We build software defined radios where we use computers to decode and encode radio signals, test back scatter using all manner of signal processing, use packet radio, RTTY, Hellschreiber and bounce signals off the moon and nearby meteors or an overflying aircraft. We make auto-tuners with a Raspberry-Pi or an SWR meter with an Ardiuno. We build valve based amplifiers and program mp3 voice-keyers, GPS lock radios, map propagation using the internet and have a rag chew on the local 2m repeater. We investigate 13cm propagation, do experiments with amateur television and we set up radio stations on top of mountains, in light houses and on remote islands. All of this is amateur radio, and frankly I've only just scratched the surface. There are heated discussions about if a linked repeater using the internet to create the link is real amateur radio or not, whether using your mobile phone as a node on the Echolink network is real amateur radio or not, if using a computer to create contacts on a digital mode such as JT65 is real radio or not. Each of these questions highlights a misconception about our hobby. There are no boundaries in amateur radio. We're a bunch of inventors, mavericks, people who attempt the unthinkable, try the impossible and make progress. There are people who are passengers on planes, and there are people who fly them. There are people using technology and there are people who invent it. We have a unique perspective as a community. We have the ability to imagine something that doesn't yet exist. Why would you spend any energy on whether that thing is real amateur radio or not? Amateur radio is a myriad of things, some of them related to antennas and radio spectrum, some not. This hobby is what you make of it, so go forth and invent something, try something, get on air and make some noise! I'm Onno VK6FLAB

eBook Volume 4

Jan 3, 2018 49


Foundations of Amateur Radio is now available as an eBook. Six years in the making, after much prodding from fellow amateurs, the edited transcripts of this podcast are now available as a series of eBook volumes. Covering our amazing hobby with short discussions about hundreds of different topics. In Volume 4 - Just get started - follow my journey through the amateur radio community, how to use QSL cards, mobile antennas on HF, licensing requirements, policing the airwaves, the super check partial list, packing up coax, lightning protection and more. Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside. Amateur radio is a thousand hobbies rolled into one. I hope you find your way. I'm Onno VK6FLAB

No Onno, it's not slippery and other lessons ...

Dec 31, 2017 302


Foundations of Amateur Radio There is a saying in my family, which I'll translate into English for you, "No Onno, it's not slippery." This came about when I was ten or so and cycling with my grandmother. It was the middle of winter, it was cold, there was the promise of snow in the air, but nothing had actually fallen. On the little plants, twigs is probably a more accurate term, dotted alongside the cycle path you could see little signs of frost. I was cycling on my shiny new bike and my grandmother was following behind. We came up to a corner on the cycle path and from behind my grandmother called out that I should be careful going around the corner because it was slippery. Being the indestructible ten year old, I called back: "No grandma, it's not slippery." at which point I fell flat on my face. A few years ago I went on a camping trip with my local club to participate in a contest. One member had a tray-top ute and the idea that we could use that as the base of operation. We planned on putting up a 10m Yagi at the top of a pole. Before we started the process I was asked to test the antenna. I plugged it into my radio, keyed up the PTT and noted that the SWR was as expected, good to go. We then set about attaching the antenna to a telescopic mast. The mast is one of those awkward contraptions. Each segment is about 2.5m tall and standing on a ladder on the back of the ute is just enough height to get to the top of the segment, so you can push up the next and clamp it down. The segments are made of mild steel, so you need to be careful to keep the whole thing straight, guy-wires everywhere, people scattered all around holding on for dear life and needing a spanner to clamp down on the next segment because the locking pins had long vanished or ceased working. About 2 or so hours later we finally had this contraption in the air. Using the Armstrong rotator - a rope that you pull the Yagi around with - we could point the antenna and life was good. We had taped down the coax as we went, put in strain relief, got the whole thing just right. Plugged it in and whoa. What happened? The SWR was through the roof. No match on any band, all over the shop. Head scratching and animated discussion followed. After a little while one of my friends asked me if I'd tested the antenna. I confirmed that I had. They'd even seen me do it. More head scratching, more animated discussion. I was again asked if I'd really tested the antenna. I confirmed that I had. They asked me how I tested the antenna. I showed them. I plugged in my radio, keyed the mike and showed them the SWR meter. All good. What's the problem? At that point I was taught about having to actually put a signal out over SSB to test. If I'd used a mode like FM, or PSK on my radio, all would have been revealed. But no sound, means no power, means no standing wave ratio, since there's nothing to bounce. I am reminded regularly of this event whenever I meet my friends, not as snappy as "No Onno, it's not slippery", but memorable none-the-less. During the week I went to disconnect my radio. It had been sitting there for a fortnight monitoring WSPR signals on 6m, 2m and 70cm. If you recall, I set it up a couple of months ago to monitor the HF bands. I've not yet done the final analysis on that, but I figured I should see if I could monitor the VHF and UHF bands. I attempted to set my radio up with two antennas, but WSJT-X doesn't seem to like doing both HF and VHF monitoring in the same band plan. It complains with an alert that you have VHF mode turned on when you're monitoring HF and stays quiet when you're monitoring VHF, so in the end I turned off HF monitoring and started listening to 6m, 2m and 70cm. After two weeks of nothing, I turned it off, no reports, no point. A couple of amateurs contacted me and asked me if I was still monitoring, so I turned it on again. About a week later, I had to turn it all off overnight with a thunderstorm, but the next morning I turned...

eBook Volume 3

Dec 27, 2017 44


Foundations of Amateur Radio is now available as an eBook. Six years in the making, after much prodding from fellow amateurs, the edited transcripts of this podcast are now available as a series of eBook volumes. Covering our amazing hobby with short discussions about hundreds of different topics. In Volume 3 - Share the fun - follow the third year of my journey, how to make contacts on HF, how to go on-air QRP, propagation planning, how to deal with trolls, online resources and more. Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside. Amateur radio is a thousand hobbies rolled into one. I hope you find your way. I'm Onno VK6FLAB

Amateur Motto: Do No Harm

Dec 24, 2017 256


Foundations of Amateur Radio The social aspects of our hobby are a never ending feast of variety. Since the requirement for becoming an amateur is that you're interested, the assortment of people who arrive at our doorstep can be described as a motley crew. I once stood in a room with radio amateurs and if I recall correctly, between us we had a surgeon, a naval officer, a sailor, a truck driver, a hiking enthusiast, a computer professional, young and old. Some were retired, others hadn't started their careers, there were wealthy people and people on welfare. Some with university degrees, others without. I participate in a weekly lunch, called PRAWNHEADS, been going for 25 or so years. The name is an acronym for the Perth Radio And Wireless Noodle House Eating And Discussion Society. We have a lunch with people from all over the place, visitors from overseas, random interstate drop-ins, new and very experienced amateurs, all mixing it together for an hour or so. If you're ever in Perth on a Wednesday for lunch at noon, you should look it up. Most of my life I've been a computer geek. Some of the time I was a broadcaster on national radio, an ultra-light pilot and I'm sure there were other phases I've skipped over, being a sea-scout comes to mind for example. In those pursuits I found myself surrounded by different people, but the range of interests and backgrounds was never as wide as those that seem to be attracted to our hobby of amateur radio. I'm raising this because it pays to think about this every now and again. People with different backgrounds have different experiences, different expectations, they communicate differently, have different vocabularies, want and expect different things and while the pull of amateur radio brings them into the room, the interaction with other humans is what keeps them there. I spend varying amounts of time online in various discussion groups related to amateur radio and a vast range of communication styles is right there in front of you. Some people are brief, to the point of being perceived as abrupt, others never seem to get to the point and in-between them are the peacemakers who attempt to explain what is going on. It has been pointed out to me that I have a particular communication style that sometimes causes people to misunderstand my intent. For example, I regularly send single word emails with the word "Done", or "Huh?" From my perspective, this is perfectly clear. You write an email for me to do something and I write back "Done" when I'm finished or "Huh?" when your request makes no sense to me. We are a hobby of communication, supposedly. My experience is that we're pretty good with coax, soldering iron, antennas and making a camp site, but our communication skills let us down. We're geared up for talking to people like ourselves, but when we're confronted with people from different backgrounds, often the pitchforks, feathers and tar come out. People take offence, even when none was given, feuds start, people ostracise each other and friendships end. I get that not all humans get on with one another, but given the same interests, amateur radio, given that we're about communication, you'd think that we'd spend a little extra effort with this. Don't get me wrong, disagreements happen all over the place, amateur radio is no different, but looking at the eclectic bunch that we are, it does appear that we have more than our fair share of bullies, discrimination, acrimony and dissent, not to mention the self-appointed police men, the armchair lawyers and those subject matter "experts". I recently pointed out to a new member of our community that amateurs are in the words of Douglas Adams "Mostly Harmless". At this time of the year I think it's a good idea to spend a few moments to consider if something you said or did, could be learned from and improved. I'm sure I'll fail spectacularly on regular occasion, but I do know that I'm never intending to do harm and perhaps...

eBook Volume 2

Dec 20, 2017 47


Foundations of Amateur Radio is now available as an eBook. Six years in the making, after much prodding from fellow amateurs, the edited transcripts of this podcast are now available as a series of eBook volumes. Covering our amazing hobby with short discussions about hundreds of different topics. In Volume 2 - Find the spark - follow the second year of my journey through the hobby of amateur radio, what's the point of Morse code, making contacts during lunch, Magnetic Loop Antennas, keeping your shack tidy, the identity of your callsign and more. Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside. Amateur radio is a thousand hobbies rolled into one. I hope you find your way. I'm Onno VK6FLAB

How does Single Side Band work?

Dec 17, 2017 243


Foundations of Amateur Radio A little while ago I spent some time discussing how to test if your radio was on frequency. It generated lots of comment and email with various suggestions on other ways to do this test, but it also caused one listener to ask the question, what's this Upper Side Band and Lower Side Band thing you're talking about? In the past I've discussed the history of these two, but I've gone back to check and it doesn't appear that I've ever actually explained what exactly Upper Side Band and Lower Side Band might be and how they work and more to the point, why they're important. Let's start where you find these modes. In amateur radio, some bands use Upper Side Band and some use Lower. From a usage perspective it's pretty straightforward, but not obvious. Essentially everyone uses Upper Side Band all the time, except radio amateurs below 10 MHz. There is one exception in that, the 60m band - 5 MHz - uses Upper Side Band. The mechanics aside, what is the point, how does it work and why does it matter? If you've ever seen an AM broadcast via a waterfall display or on a spectrum analyser you'll have seen a symmetrical picture with a big spike in the middle. The spike in the middle is the carrier and the two sides are duplicate copies of each other. If you were to do some math, you'd discover that the spike accounts for 50% of the energy that's embedded within the AM signal and you'll realise that doubling the other halves takes care of the other 50% of the energy. If you eliminate both the spike and one half, you end up consuming 25% of the original AM signal - in terms of energy. That essentially means that you can now spend all of that available energy in your transmission and in effect get a signal that's four times stronger than the original AM signal. A better way to say that is, Single Side Band is four times as efficient as an AM signal. Now if you took the right half of the signal, you'd end up with an Upper Side Band signal, and if you took the left half of the signal, you'd end up with a Lower Side Band signal. The signals are identical, but they're reversed. From a technical perspective, the Upper Side Band signal represents your audio from left to right. Low, or base frequencies on the left and high or treble frequencies on the right. A Lower Side Band signal reverses that, which is why a voice sounds unintelligible if you get Upper Side Band and Lower Side Band mixed up. The alignment of the radio to a specific frequency works because you can map the audio frequency directly to the tuning frequency. That might not be immediately obvious, but let's imagine an Upper Side Band signal at 10 MHz. At exactly 10 MHz, the audio frequency of 0 Hz is represented, at 10.001 MHz the audio of 1 kHz is represented and at 10.002 MHz, the audio of 2 kHz is represented. If your radio is off frequency by say 50 Hz, then the sound you'll hear will be off by 50 Hz across all of those. So 10.001 MHz won't sound like 1 kHz, it will sound like 950 Hz and 2 kHz will sound like 1950 Hz. On the other side, if you flip to Lower Side Band, 1 kHz will sound like 1050 Hz and 2 kHz will sound like 2050 Hz. Upper and Lower Side Band, nifty solution, better signals, less bandwidth use and all in all a great way to play with radio. Remember, everyone uses Upper Side Band all the time, except for radio amateurs below 10 MHz but not on 5 MHz. I'm Onno VK6FLAB

eBook Volume 1

Dec 13, 2017 47


Foundations of Amateur Radio is now available as an eBook. Six years in the making, after much prodding from fellow amateurs, the edited transcripts of this podcast are now available as a series of eBook volumes. Covering our amazing hobby with short discussions about hundreds of different topics. In Volume 1 - Join the hobby - follow my initial journey through the community, what to buy when you start, how to participate in the community, things to practice, what the first steps look like once you have a license, playing in radio contests, encouragement and sharing. Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside. Amateur radio is a thousand hobbies rolled into one. I hope you find your way. I'm Onno VK6FLAB

60 years of amateur radio

Dec 10, 2017 208


Foundations of Amateur Radio This morning I spoke with two amateurs on-air. Not that surprising, since I was hosting a weekly net called F-troop for new and returning amateurs. Both amateurs came on-air for the first time in our net, one licensed sixty years ago, the other six days ago. It didn't strike me until long after the net had finished that these two amateurs have a completely different experience in this shared community. One started in a world where megacycles were common, the other knows them as megahertz, one purchased their radio in parts, the other purchased it online, one heard Donald Duck sounds and needed to read about a new mode called Single Side Band, the other is going to be reading about digital modes and how they work, one was dealing with analogue television interference, the other is dealing with plasma screens. Both these operators share many things. They are both licensed radio amateurs, both have the opportunity to participate in contests, attain their DXCC, pull out a soldering iron, participate in social activities and become members of their local radio club. If during their first year as an amateur both of them read Amateur Radio magazine, the members' periodical published by the Wireless Institute of Australia, they'd both find the rules and the results of the Rememberence Day contest, field days, letters to the editor, instructions on how to build antennas, including detailed instructions on building a 2m Yagi, information from the QSL manager, DX activity reports, the new Australian call book and information about the local news broadcast which continues to go to air on Sunday morning at 9:30am local time. In the intervening sixty years amateur radio has changed a lot, but it's also stayed the same. A radio from 1957 will still be able to communicate with a radio from 2017. Imagine that for a moment. Electronics during those sixty years saw countless dramatic changes. For example, Fairchild Semiconducter one of the pioneers in the manufacturing of transistors and integrated circuits was founded in 1957. Imagine that, the introduction and obsolesence of transistors within those sixty years. The first integrated circuit build by Jack Kilby in 1958 was a phase shift oscillator, consisting of one transistor and a handfull of capacitors and resistors. Today an integrated circuit contains 25 million transistors per square millimeter with some chips being up to 600 square millimeter in size, that's 15 billion transistors. The mind boggles what has happened in those sixty years, but the most satisfying part of all this is that both these amateurs can come on-air, join a net and participate in the hobby today. If that's not the representation of an amazing hobby, then I don't know what is. Thank you to Sandy VK6FBHW and Brian VK6DAD. I'm Onno VK6FLAB.

Leave judgement outside the shack ...

Dec 3, 2017 259


Foundations of Amateur Radio Today I'm here to tell you that I'm in the process of writing a book, actually seven of them, and to be precise, there's more of editing than writing, since I'm putting together all of my podcast efforts over the past seven years. Nice how that works out, seven years, seven books. Most of the effort is in proof-reading my work. Do I spell radio amateur with capital letters, or not, do I use my word-processor to replace all occurrences of radio amateur without capital letters and what happens when I refer to them as radio amateurs instead? You get the drift, lots of minutia, consistency and every now and then a little edit to make a sentence make sense to a reader. As an aside, if I don't get distracted by life I'm planning to publish in the next week. The unexpected joy I'm getting from this experience is to read about my adventures and to remember some of the adventures that you have told me about, things I've been working on, events that you and I attended, contests, victories and frustration. One thing I've noticed, something that you're likely to observe once in a while by accident, is the immense variety of activities that encompass this wonderful hobby. There are build projects, activations, social outings, research activities, laughter, joy, disgruntlement, dissatisfaction and triumphs. I've said many times that this hobby of ours is 1000 hobbies in one and reading back, I suspect that 1000 is underselling the experience. Going back also shows that learning Morse code has been on the books for a long time and clearly I'm stumbling on some roadblocks there. My DXCC adventures continue to grow one contact at a time, my mobile setup is working well compared to other methods of activating my station and new adventures appear just around the corner waiting to be discovered. I'm in the middle of my next adventure. Adding crystal filters to my radio, installing a temperature compensated crystal oscillator, finding out about the drift and frequency accuracy, all these are part of a much larger project. The next step is finding a suitable antenna. I'm still on the fence between building and buying. It's a joint decision with a fellow F-call, and we're working through this adventure together to see where it might lead. Our skill-set is completely different, with different perspectives on the same thing, different tools we bring to bear on the challenge we've set ourselves and that in and of itself is a fun experience to have. We've spent some time together talking about the landscape we're stepping into and I think it's safe to say that we can both learn a lifetime of knowledge from the other person, if our life outside amateur radio doesn't intrude - hi hi. The point of this observation is that I've noticed over the years that there are amateurs who leave the hobby, never to return. Some would say: "Good riddance!", but I think that given the infinite breadth of this hobby and community, each of those people leaving makes for a poorer experience for them, and also for us. I'll be the first to admit that I have disagreements with fellow amateurs, sometimes very strong disagreements. I know that this is true among other amateurs as well. This is not particularly unusual in a technical pursuit like our hobby, I see it in my professional life in computing as well. The thing that should set us up for a better experience is that we're all about communication in this hobby, but there are times when I wonder if we just pay lip-service to that notion, rather than attempt to be tolerant, inclusive and welcoming. Perhaps it would be wise to add another thing that should be left out of the ham shack, together with talk about religion and politics, perhaps we should leave judgement at the door as well. I think it would be a good idea to learn how to do that, perhaps bite our tongues a little more, take a breath, ask the other what they're thinking, rather than rant back and forth between two...

How can you measure what frequency your radio is on?

Nov 26, 2017 315


Foundations of Amateur Radio The frequency you listen and transmit on in a modern radio is derived from a crystal master oscillator, in my case 22.625 MHz. That master frequency is multiplied and divided to determine the final frequency. To get to 2m you need to multiply by 6. To get to 70cm, multiply by 20. Similarly, to get to 40m, divide by 3. Any slight variation of crystal frequency has an impact. 100 Hz variation in the master oscillator causes the radio to be off by 600 Hz in 2m, or 2000 Hz in 70cm. The higher you go the bigger the error. This leaves us with two problems. If the crystal changes frequency over time, your radio wanders with that change which is especially noticeable on the higher frequencies. I've previously discussed how you can deal with the variation by correcting for temperature. The other problem is the actual absolute frequency. If the radio is set-up for a crystal with one frequency and you replace the crystal with a different one, how do you know what frequency you're actually on? Your dial says one thing, but is that the actual frequency? How do you measure any difference? Is a new radio the same as an old radio, does the frequency change over time? Measurement is the act of comparing two things. Think of a ruler, wooden stick with markings on it. If the lines on the stick are not drawn in the right place, anything you measure with that stick will not match other sticks. That won't matter if you only ever use your stick to build everything, but typically you use parts supplied by someone else with their own measuring stick. In your radio the same is true. What the actual frequency is doesn't matter until you need to compare it to the frequency of someone else. Like say, another radio station. The first thing we need is something to compare with, a reference frequency. As it happens there are several of those around. As an example, you'll find reference broadcasts on 5 MHz, on 10 MHz, 15 MHz and 20 MHz. There are countless other frequencies where you'll find radio time signal stations. These stations broadcast on a steady frequency with a defined signal that you can use to do measurements against, even your local broadcast stations have a carrier that you can get started with. A typical radio time signal will be an AM station with all manner of information encoded on the transmission. You can tune your radio to the station and hear a talking clock, second marks etc. Unless your radio is seriously out of whack you're unlikely to be able to notice any frequency errors. If you tune to the same station with side-band you'll hear some artefacts, but essentially you'll hear nothing. However, if you tune slightly off frequency, you'll hear a tone. This tone is the central carrier frequency and it's very accurate. At this point you can do many things. I'll cover one of them. I'll explain this with 10 MHz. If you set your radio to Upper Side Band and tune to 9.999 MHz on your radio, you should hear a 1 kHz tone. Similarly if you set your radio to Lower Side Band and tune to 10.001 MHz you'll also hear a 1 kHz tone. In essence you're listening to the carrier as a 1 kHz audio tone. You can swap between the two frequencies, by setting one on VFO-A and the other on VFO-B and switching between them with the A/B switch on your radio. If the tone changes, your radio is off frequency. How much off frequency is determined by the difference between the two tones. By lowering both frequencies by the same amount, or raising both by the same amount, one of the tones will go up while the other one goes down and vice versa. Once you've got both the tones the same, write down both frequencies. Split the difference and you'll know what frequency your radio thinks 10 MHz is on. You'll need a radio with both Upper and Lower Side-Band and the ability to switch between two frequencies and before you get started, you need to make sure that your radio doesn't have any frequency changing stuff turned on, RIT,...

How does a Temperature Compensated Crystal Oscillator work?

Nov 19, 2017 216


Foundations of Amateur Radio You know when you walk down the street and you lift your foot and all of a sudden you realise that you stepped in something and now it's stuck to your shoe? I had that feeling during the week. Last week I mentioned that I had purchased a TCXO, a Temperature Controlled External Oscillator. Lowell NE4EB set me straight by pointing out that XO stood for crystal and that TCXO stood for Temperature Compensated Crystal Oscillator, which then lead me on a merry goose-chase trying to learn about all that. I mention this because while the stickiness on my shoe kept me busy, it also highlighted that I'm still a babe in the woods on a steep learning curve to knowledge with some roadblocks, diversions and potholes along the way. That reminds me, if you ever feel the urge to pull me up on something I've said, you can email me via my callsign at gmail.com. So, how does this Temperature Compensated Crystal Oscillator actually work? Without getting into the circuitry behind the scenes, as I mentioned previously, a crystal oscillates and the frequency is dependent on temperature. Turns out this is a predictable curve, which makes it possible to account for changes in temperature. In addition to keeping the temperature stable, another way to keep the frequency of a crystal stable is to have an electrical circuit that changes depending on temperature and have that create something like an opposing curve, so you can add the two together and end up with a pretty stable frequency. Before you start asking how exactly, let me just remind you of the shoe with the stickiness on it. In essence you have something like a resistor that changes resistance depending on temperature, it's a component called a thermistor, and that in turn affects a resonant circuit, also known as an Electronic Oscillator, or LC circuit, which in turn affects the circuit that is driving the crystal. These days most if not all of that is on a chip and you get a neat little package that you can plug into your radio to give it frequency stability and hopefully accuracy. I did say I was going to talk about accuracy this week, but the doo-doo I stepped in put a swift halt to that. Besides, now I know that there is a thing called a thermistor, the second portmanteau I ever learned, together with Gerrymander, so there's that - oh, also, Tanzania, Eurasia and Oxbridge. Back to Amateur Radio. The oven controlled crystal I mentioned last week, they exist in high-end measuring gear, not in the $26 TCXO I have installed in my radio. While I'm on the subject, you can also compensate for temperature with software, using either a purpose built micro-processor, or even the host processor that is using the crystal, but that gets into magic self-referencing voodoo pretty quickly. And while I've been playing, Japan is finally being received here and I heard a station 18656km away during the week. Mind you, AA3GZ in Doylestown, Pensylvania, on the Atlantic Ocean side of the United States was putting out 100 Watts, so there's that. I'll leave you with a thought that I hope to be able to answer next week. If your radio has a crystal that determines what frequency it's tuned to, how do you use that to determine the accuracy of the frequency, more self-references, just because I can and besides, I'm a software developer and recursion is part of my make-up. I'll give you a hint, it's not all to do with MHz. I'm Onno VK6FLAB.

What did you hear last week?

Nov 12, 2017 359


Foundations of Amateur Radio Last week I spent a little time talking about the Weak Signal Propagation Reporters network, or WSPR, pronounced Whisper. You might remember that I set up my radio to receive these signals to see what I could learn. Turns out, I learnt quite a bit. I left the software running for a week. During that time my station reported 456 signals received with a total of 54 stations in 27 call areas. The longest distance 14,000 km, PC1JB in Veenendaal in the Netherlands who was using 1 watt. The best performance based on km per watt is R0AGL in Siberia, 10,000 km, with 2 milliwatt. Highest power heard, one station with 100 watts, but from a performance perspective, only just squeaks into the top 10 contacts. Typically stations used 5 watt or less. My 10m quarter-wave vertical antenna was pretty good in hearing things across all bands. I heard stations across the frequency range, from 160m through to 10m. It heard 1 station on 160m, VK7MF, using 5 watts, 3,000km away. The most prolific band was 40m, accounting for 41% of the signals, 30m was pretty close at 35% and even 10m was respectable with 5% of signals heard on that band. Which brings me to a comment about propagation. The Solar Flux Index this week was pretty abysmal. It's been the lowest it's ever been, 66 and still I was able to hear signals across all HF bands. Just think about that for a moment. All the solar numbers say the bands are dead, all the listening in the world says the bands are dead, but using WSPR reveals that this isn't true, it's not even close to being true. My station in a very high noise environment still heard signals across all bands. Based on a visual comparison with other stations, signals were generated in all directions, but for my station, I didn't hear anything coming from the North East Quadrant, that's between North and East. It could be that the signals are being suppressed by the distortion in my antenna pattern, which might be caused by a metal gutter in that direction, or it might be that signals coming from that direction, mainly Japan and the United States, are too weak to be heard above the noise level at my station. I'm investigating that further, but that's for another day. Speaking of other stations, in total during the same period as my station listening, there was a total of 6.9 million reports, representing 2490 listeners and 4463 transmitters. That means that I heard just over 1% of stations on my radio. Not bad given my meagre set-up and minimal configuration and installation. On to things that I was attempting to learn about the performance of my radio. Every WSPR transmission includes the frequency and location information, which allows you to determine what the difference is between what frequency the other station reports and what frequency your radio sees. Of course, there can be variation across both radios and to make things more interesting, this changes over time. This drift is likely to be distributed pretty evenly across all stations, but then I didn't hear all of them, so my results are not completely definitive, but overall the drift reports show a frequency drift of minus 3 to plus 2 Hertz. Slightly skewed down. That's not yet conclusive proof that my station is slightly off frequency, but it seems to indicate that my new crystal is slightly low. I'll be investigating that further. And that neatly brings me to why I have been doing this. You might not be surprised to learn that many things inside your radio are frequency controlled. Those frequencies come from a single central location, a master oscillator that in my radio vibrates at 22.625000 MHz. The crystal that does this is affected by temperature. When you transmit, the radio heats up and the frequency of the crystal changes slightly. Normally this isn't an issue, but if you're working on being on a particular frequency, especially on the 2m or 70cm band, then this starts to matter. If you leave your radio running for...

Hearing very weak signals

Nov 5, 2017 230


Foundations of Amateur Radio This week I'm going to talk about a Digital Mode you can use with any Amateur License, or even without an Amateur License. You can set-up your radio, hook it to a computer and the Internet and after installing some software, you can join the Weak Signal Propagation Reporters. So how do you start, what does it do and how can it help you? First of all, WSPR, pronounced Whisper, is a way of encoding information and transmitting it across the spectrum. At the other end a radio receives that signal, sends it to a computer where a piece of software attempts to decode and then log it. This Digital Mode, invented by Joe K1JT, is one of several modes that are gaining popularity across the Amateur Radio community because the beauty of this mode is that it's so unobtrusive that you're unlikely to actually hear it if you were to tune to a dedicated WSPR frequency. If you want to find out what your station can hear, you can set yourself up as a dedicated receive-only station and report your findings to a central database where others can share your information and learn what propagation is like at that particular point in time. Of course, it also means that you can use the same information to learn what propagation looks like in your neck of the woods with your radio and your antenna set-up. There's even an option that allows you to have your radio automatically change frequency - known as band hopping - and listen for WSPR signals across the bands that you allocate. If you like, you can go to the wsprnet.org website right now and do a search for my callsign, VK6FLAB and see what stations I've heard since I turned it on. Go on, have a look, I won't mind. My station is set-up to do band hopping across all HF frequencies all day and night and during the grey-line it only listens to 80m, 40m, 15m and 10m, since those are the frequencies my license allows me to transmit on and I'm particularly interested how they work at sun-rise and sun-set. You might have heard me before talking about how the noise at my home is atrocious. Nothing has changed, it's still abysmal, but WSPR signals are coming in and being decoded. If you want to do this, you'll need a radio - any radio will work, a computer with a microphone socket and a way to pipe the audio from the radio into the computer, I'm using a 3.5mm male plug to 3.5mm male plug - you don't need a fancy audio interface, you're only listening. If you can connect an interface cable, your computer can also change frequency for you, but that's not needed to get started. Make sure that you turn the volume right down before you plug anything in. Connecting a headphone output directly into a microphone input can blow up the port if you're not careful and WSPR doesn't need much in the way of volume. The software helps you get it set right, so read the manual before you start. Once you've set-up your radio and your computer, you can watch the signals coming in on a waterfall display, a graphical representation of the audio and frequency that shows strong signals in red and no signal as blue. You'll find that turning up the volume too high will actually reduce the ability to hear signals. I'm keen to learn what I can hear and how many stations my simple 10m vertical antenna can hear across the Amateur Radio spectrum. I'd love to hear your weak signal stories and see what you can hear. As I said, it seems I'm becoming a short-wave listener after-all. I'm Onno VK6FLAB

Radio signals don't travel in straight lines

Oct 29, 2017 155


Foundations of Amateur Radio The other day a friend of mine asked a really silly question. How come when I point my YAGI at a direction for a station using the great circle, the signal is there but weak, but when I point it in a different direction, say 20 degrees away from the great circle, the signal improves? Being a good little Amateur, I responded with the logical explanation. Well, two things come to mind, one being that you're not pointing where you think you're pointing, that is, North on your antenna isn't North in reality, so when you point at the other station, it's not actually where you're pointing, and when you adjust, the antenna ends up in the correct direction. Another explanation I came up with is that the pattern of their YAGI isn't what they expect. There might be local factors that influence the pattern, putting weird distortions into their foot-print and making for "interesting" nulls where there should be signal, and vice-versa. That in turn started a whole conversation about directions and where stations are. Leaving aside the difference between long-path and short-path, which I should probably talk about at some point, an antenna should get signal from the direction in which you point it, right? So, what if I told you that the antenna was in fact pointing correctly and there were no distortions in the antenna pattern, what then? Turns out that the Ionosphere isn't uniform - who'd have predicted that - in case you're wondering, that's a joke - the Ionosphere isn't uniform, it takes in many and varied influences, from the earth's magnetic field, to heating by the sun, to solar storms, coronal mass ejections, and any number of factors that we as a species are only just beginning to discover. If you imagine for a moment a radio-wave coming up from your antenna, bouncing against the Ionosphere, back to earth, then bouncing back up, then doing the same thing again, you'll quickly understand that because the Ionosphere is variable, the height and angles at which this bouncing is occurring varies along the path. But here's a shocker, who said that the signal had to bounce up and down vertically, what if the same variability of the Ionosphe height caused a signal to bounce in some other weird direction, like at an angle, or side-ways. Would the path of the signal from your station to the other end follow a great circle line? Turns out that this silly question wasn't silly at all and I learned something unexpected, my radio signal isn't a straight line, something which I confess, did come as a surprise, but now, looking back, seems pretty obvious. I love silly questions, they often turn into an opportunity to learn. I'm Onno VK6FLAB

What to pack for a Contest?

Oct 22, 2017 199


Foundations of Amateur Radio In the past I've talked about what kind of station I have, how I tend to operate and what kind of tools I use in my day-to-day running of an Amateur Radio station. This week I want to take a closer look at what I do when I participate in a contest. I remember fondly the first contest I ever set-up for, fondly as-in, "What was I thinking?" Let me set the scene. I'd previously been to a few stations that were participating in a contest. Some of those were in a club-shack, others were set-up portable in the field. For my first contest I was going to set-up my station in the field, so I needed to bring everything myself. Fortunately I was with friends, one with a camper-trailer, so I didn't need to bring a roof, or the kitchen sink, but I did bring pretty much everything else. My list included tables, chairs, antennas, radios, headphones, connectors, soldering iron, power-boards, extension cables, logbooks for paper logging, pens, clipboards, two computers, four spare batteries, power supplies. It took hours of preparation, packing and not to forget, lugging, and when the contest was all done and dusted I noticed that while I brought everything, I didn't bring the right things and some things were missing. For example, the little connector cable between the front face of my radio and the back of my radio was not packed, so I could only work with a long cable, which was subject to interference which I couldn't fix because I didn't have any ferrites. Other missing tools were a multi-meter, an antenna analyser and a dummy load, to name just the ones that come to mind today. A wise man once told me that the more you camp, the less you bring. Combined with my first contesting experience, that's become my motto. Bring Less. So last week, I packed much less and much more precise. My total packing list was: A radio and a tuner, wire for wire antennas, crimp connectors and a crimper, a multi-meter and antenna analyser, a dummy load, barrel connectors and adapters from N to PL259, BNC and the like. A computer for logging and a CAT cable, a headset, a foot pedal, a notebook and pen. That's it - other than a toothbrush and a sleeping bag and warm clothes. As it was, my foot pedal didn't work, because there was a fault in the adapter cable and I've added fixing that to my list of to-do items. Which brings me to the next thing I learned. It doesn't matter what you start with on your first contest. What matters is that you track it and then after the contest try to spend some time figuring out what worked and what didn't. If you update your list then over time it will become better and targeted to your specific circumstances. When I do a contest mobile from my car, my packing list is similar, but not the same. I've not yet got it down to a fine art, but I'm getting better. One day I'll have the perfect kit, but then something unexpected is likely to happen and the perfect kit will change, again. What is currently in your contesting list, what do you bring and what do you leave at home? What adventures did you have with your latest contest and what lessons could you share with others? I'm Onno VK6FLAB

Ladder Line is not Evil

Oct 15, 2017 308


Foundations of Amateur Radio The way we connect our antenna to our radio depends on a number of different factors. If you've come through the ranks recently, like I have, it's probable that you've only ever considered using COAXIAL cable. It's a single conductor, surrounded by some type of insulator, which in turn is surrounded by a conductive shield, which is protected by another layer. There are variations where the shield has multiple layers, including layers of foil and braid, so-called quad-shield COAX, and there are variants that have several cores, sometimes two sets of COAX connected side-by-side and so on. In many ways, COAX is an invention of convenience, which has several compromises as a result, loss over distance, termination issues, twisting and deformation and others. It's compact, less susceptible to external interference, it's relatively easy to route to its destination and if you treat it well, it's easy to carry around, but it's not the only way you can feed an antenna. You may have come across the term Ladder Line or Twin-lead, or Twin-feed line. You may also have heard horror stories associated with this "ancient" - well at least in Amateur Radio Terms - technology. Essentially, Ladder Line is two conductors, side-by-side, evenly separated by spacers. It's in use all over the place. If you look up at your power-lines in the street, or the high-voltage lines on top of towers, you'll notice that those are essentially Ladder Line. You've no doubt been told that you need to keep Ladder Line away from everything, in order for it to work, but that's not actually what's needed. What's required is that both conductors are exposed to the same fields. This means that if you're running the Ladder Line through a metal window, you need to ensure that both lines get the same amount of exposure to any nearby metal, you might put a slight twist in the Ladder Line, or you might put it in the middle between two bits of conductor, like a metal window frame. You might also have been told that Ladder Line radiates. It does, but only if the antenna you're feeding isn't balanced, because what actually happens is that the two sides of the antenna don't cancel each other out and the difference is radiated by the Ladder Line. It's worse if the Ladder Line is some resonant length on the frequencies on which you're using the antenna, because it will receive the signal from your antenna and re-radiate that too. It really means that you need to pay attention, but the cost of that attention pales into insignificance, if you think of the benefits. You might recall that your radio is most happy when it's transmitting into a 50 Ohm load. One of the measurements associated with that is an SWR reading of 1:1. This has come to be interpreted as: "You need a 50 Ohm antenna in order for it to radiate." and that's not actually true. All antennas will radiate, and as long as they are at least half a wave length long, their efficiency will be about 90%. The problem isn't the antenna, it's how you feed the antenna. As I said earlier, if you're a relatively new amateur like me, you might have put one and one together and decided that you need to feed it with 50 Ohm COAX and that your antenna needs to be 50 Ohm. If you do that, it will work, but it's not the only way. The reason you need to have a 50 Ohm feed-point to plug your COAX into, is because the COAX has a lot of loss if there is a feed-point mis-match. The higher the mis-match, the higher the loss. For example, using an 80m Dipole on 40m might mean an SWR of 65:1. This has about 80% loss on 100 feet of RG-8 COAX at 7 MHz. All you're doing is heating up COAX. However, if you were to feed it with 600 Ohm Ladder Line, the loss might only be around 3%. Before you start getting out the calculator to prove my maths wrong, this isn't about maths, it's about the difference between Ladder Line and COAX. COAX is wonderful as a tool, but Ladder Line should not be consigned to the annals...

Organisation around your shack

Oct 8, 2017 208


Foundations of Amateur Radio The art of keeping your station organised and accessible has much to do with choosing wisely which bits to keep and which bits to throw. That's part of the story, but there are other aspects of organisation that will assist you. Rolling up coax is a skill that you need to learn. The over and under method of coiling cable is by far the easiest way to ensure that your coax stays healthy and happy without kinks and other distortions. Once you've coiled your coax, many amateurs use electrical tape to hold the coil in place for storage. This can be helpful, since it means that you'll always have a handy supply of electrical tape on hand for when the need arises, but an alternative is to use Velcro cable wraps which attach semi-permanently to one end of the coax and can be wrapped onto itself to make a loop around the coiled coax. Making a water-proof connection, for temporary use can be as simple as covering it in electrical tape. This isn't ideal and not permanent and water inside coax is a guaranteed way to create problems that go well beyond the one time that it got wet, with rust and rot destroying the connector, then the conductors and then ultimately your radio. A better solution is to use either self-amalgamating tape, or plumbing tape to cover the join, followed by electrical tape and even cable ties to ensure that the tape stays in place. There are self-amalgamating dispensers that allow you to coat a connector in a sticky goo that also keeps water out, but getting it off at a later stage is guaranteed to make your hands black and sticky. If you're operating portable, then getting your wire into the air might be associated with throwing something into a tree to pull your antenna up. A fishing rod is a very helpful tool, complete with some fishing weights, to get the wire into a tree. Bring spare sinkers because you're going to lose some along the way. Storing a cable or stay kit is often a laborious affair with the rope getting tied up in knots throughout your kit with the next 30 minutes spent untangling the almighty spider-web that magically appeared inside your go-kit. A great way to prevent such an adventure is to invest in different size zip-lock bags. You can label the bag appropriately and see inside what's there, so if you have a few of them, you only need to grab the one you need and use different sizes for different purposes. Too small means they pop open and too large means you can't find what you need. Bring along some ratchet straps. They don't need to be 20m monsters, 2m is just fine, but bring a few. You'll be surprised how often they come in handy to tie down a radio, or a squid-pole, or strap a clipboard to something. A clipboard is a useful surface to write on, to keep your logs and if you get a clipboard box, you can store your electronic log keeping device and some pens in the same place. At one point I actually attached the head of my radio to my clipboard with some screws which made operating and logging even easier. No doubt you've got some tips of your own, so feel free to drop me a line and share. I'm Onno VK6FLAB

A transistor radio curve-ball ...

Oct 1, 2017 223


Foundations of Amateur Radio Today I have a confession to make. Looking back it's clear that once your brain goes down a certain path, it's easier to follow the path than to find an alternative one. When I was growing up, above my bed, bolted to the wall were two brackets. On top of those brackets, secured with double-sided tape was a radio-cassette player. If you're unfamiliar with what an audio cassette is, don't worry, this is about the radio side of things and is from the days when Digital Music was not in wide use like it is today. I used this radio to listen to local stations, both on the AM and FM broadcast band, and I managed to even get to the beginning of the FM broadcast band where the police radio happened to be at the time in the country I was living. As years went by, that radio-cassette player was replaced with a radio tuner, then a combined amplifier tuner and I re-programmed it as I moved around the globe with new local stations filling up the quick select button memories. Over the last year or so it occurred to me that my latest device had been sitting inside a box in the garage for the better part of a decade and that the gap was filled by the radio in my car. I would drive somewhere and turn on the radio and listen to something interesting, or something boring, depending on what the airwaves brought to my antenna at the time. I started wanting to listen to the end of interviews, or rock along to some other happy tune when I got home, but I found the transition to be painful. I experimented with streaming radio, spent hours looking for software and currently the best I can do on that front is to have an App on my phone that streams a local radio station. You're likely by now doing one of two things. We'll get to the second one in a moment. The first one is probably going to be along the lines of "Yeah, so, what exactly has this got to do with Amateur Radio again?" If you're not thinking that, you might be thinking something that only occurred to me last week. "Why don't you use your Amateur Radio and tune that to a local broadcast station?" Indeed, why not? I'd never considered that even though my Yaesu FT-857d can tune from 100 KHz through to 470 MHz, covering most of the Amateur Bands, I'd never considered that it would also allow me to listen to a local broadcast station. It's not that I haven't actually tuned to those stations, or listened to the local Air Traffic Control frequencies, or the local Non Directional Beacons when they still existed, it's that those activities were in the context of Amateur Radio, along the lines of propagation, or interesting signals, not background music, or listening to an interview or a talk-back station. I've not yet gone to the trouble of pre-programming those stations, since my Amateur Radio is sensitive enough to pick up stations that my car cannot hear, but the list of frequencies that I'm tuning to during the day, using AM and FM is growing. Shame I can't get FM stereo from my Yaesu radio, perhaps that's something I should play with at some point. So, my second point is, "Duh, my Amateur Radio is also a radio, that you can listen to other broadcast stations with." Of course, it's a pretty pricey transistor radio, or short-wave radio, if you think of it like that, but if you've got it sitting next to you right now, it's simpler than making streaming radio work. I started this with paths travelled and I'll finish with that. When something like this happens, stop for a moment, celebrate the insight, share it with others and who knows what other things will bubble up. When was the last time your brain surprised you and what do you listen to that's not Amateur Radio? Who knows, I might become a short-wave listener yet! I'm Onno VK6FLAB

Tropospheric Ducting explained

Sep 24, 2017 217


Foundations of Amateur Radio You've always been taught that VHF communications are line of sight and that the height of your antenna determines how far your 2m communication might go. So if I tell you that last week I spoke with a station that was 300 kilometres away on the 2m band you might be forgiven in thinking that I had managed to climb up most of the side of Mount Everest to around 7 kilometres so I could make my line-of-sight communications 300 kilometres away. I'll give you a hint. I was at my home, my house isn't on the side of Mount Everest and we were both using normal gear, nothing crazy, no amplifiers, no glitzy antennas, just the basics. So what's going on? There'ss a phenomenon called "Tropospheric Ducting" that comes and goes and if conditions are right, allows you to extend your line-of-sight communications to distances far beyond your imagination. So, what is this thing and how does it work? First of all, this is something related to the lowest part of the atmosphere, called the troposphere. It has nothing to do with the ionosphere which we know and love and use regularly to make long distance communications on the HF bands. The ionosphere starts somewhere about 60km up, the troposphere stops at about 12km. Tropospheric Ducting happens much lower down. At the most around 3km up, but normally between 500m to 1500m. In essence a Tropospheric Duct is a layer of warm air trapped between two layers of colder air that acts as a tunnel for radio signals. These kinds of layers aren't caused by "weather" as such, but by climate conditions such as weather fronts. Normally as you go up into the atmosphere, the temperature drops. The rate is around 6 degrees Centigrade per kilometre. Without going into the fascinating science behind it, think about it as a phenomenon where you'll find different types of layers of air over the top of each other, each with their own density and temperature. When the conditions are just right, you get a tunnelling effect that allows you to make some very long distance communications. There's reports of signals travelling over 4000km and if conditions are right, you might be able to hear such long-distance signals on your house-hold FM radio. One aspect that you might not have considered is that the thickness of the sandwiched warm layer determines which frequencies can travel along this so-called tunnel. If the thickness is 15m, you can expect to hear 11 GHz signals, 90m thickness gives you 400 MHz propagation and 180m thickness gives your 140 MHz signals a path to travel. If you manage to find a layer that's 430m thick, you might even manage to make contact using 29 MHz using a Tropospheric Duct. Now, you might be forgiven in thinking that this is all voo-doo and unpredictable, but it turns out that there are plenty of things that you can use to observe that conditions might be right. If you have local fog, or smog trapped over your station, you might be able to take advantage of this phenomenon. It's not that the smog or fog is causing the duct, it's that they happen to occur at the same time as the ducts are created. If you see a sharp layer in the sky, then turn on your radio and have a gander. I won't guarantee success, and you can look online for William Hepburn's World Wide Tropospheric Ducting Forecast, but you really don't need that to get started. Tropospheric Ducting happens all over the planet and it might be happening right now. I'm Onno VK6FLAB

Storing your Amateur stuff ... everywhere.

Sep 17, 2017 174


Foundations of Amateur Radio There is so much stuff associated with Amateur Radio that your family might be forgiven in thinking that your hobby is all about being in the middle of a junk-yard surrounded by the carcasses of disassembled gear, components, failed projects, obsolete equipment and scraps of wire, solder and countless screws, resistors and other bits and pieces that are just too valuable to dispose of. During the week I was given an incentive to reorganise my work-shop. I set aside an hour to do it and unsurprisingly, armed with 20/20 hind-sight, it took a day to complete. The upshot of this activity is that I can now walk into my work-shop, something which I couldn't last week, and to top it off, I could actually find things. I confess that I've reorganised my work-shop several times over the years, but each time I find that it returns to its natural state of junk everywhere. I have noticed that this state is taking longer and longer to achieve, which means that I am improving things, but not quite as well as I would like. The biggest improvement I found last time around was to install shelving. I also used cardboard boxes to put stuff into, but that turned out to be a mixed blessing, tidy, but unusable, since I had to keep stacking and un-stacking boxes to see what was inside and writing on the outside only helped if the list of what was in the box was complete, which I'm sure you know, is never ever the case. This week I made an incremental change. I have purchased a whole slew of transparent plastic boxes, about the size of a shoe box each, with lid, stackable and big enough for most of the things I need to store. I've arranged the boxes along several shelves, stacked two high, so you only ever have to lift one box if you need to get to the bottom one. When ever I go into a bottom box, I move it to the top, so over time the most used boxes will be on top and the ones I don't use often will be on the bottom. Now I have a box with Velcro straps, one with cable ties, one with electrical tape, one with self-tapping screws, one with audio connectors and so-on. Time will tell if this helps. You might recall in the past that I've also got a stack of fishing boxes. Not a whole tackle box, just a single layer box with square compartments, removable dividers, just large enough for about 4 PL259 connectors in each. They're also transparent and stackable. Each compartment has some unique component. Red Anderson Power-Pole shells in one, Black in the next, Green, Purple, Yellow etc, each in their own little space. The connector innards are in another compartment, the joiners in another, BNC male connectors in another, and so-on. I've seen similar attempts at organisation using glass jam jars, but in my experience they don't stack well, are never uniform, unless you have 100 identical jars and are not compatible with concrete floors and gravity. I'm sure that I've missed some salient storage advice, so feel free to drop me a line and share your experiences. I'm Onno VK6FLAB

Amateur Radio Regulation and Enforcement in Australia is Broken

Sep 10, 2017 149


Foundations of Amateur Radio The other day a fellow Amateur was relating their experience in the hobby. They spoke of interference, jamming, breaking in over the top of contacts and generally being hounded by special people who think it's their purpose in life to make life miserable for others. I have spoken in the past about similar experiences that I had with individuals jamming a weekly net that I've been hosting for new and returning hams, and occasions when I've been on-air with a special callsign with an individual yelling "pirate" at the top of their lungs in an attempt to get me off a particular band, even though I was operating in compliance with the license conditions. I've personally made complaints to the regulator about these occurrences, who then decided that being interfered with for over a year was something that the repeater owner should complain about. When they complained, they were told that there was not enough evidence, or some such excuse, I forget exactly the details, but the problem was never investigated or regulated. I contacted the regulator to advise them of interference of our National Broadcaster on a particular frequency, on a particular stretch of road and their response was that it wasn't their problem to fix - even though the Australian Communications and Media Authority is specifically the spectrum regulator. One particularly funny, though not in a hi-hi kind of way was when I was speaking with an investigator who asked me how I knew about interference. I explained that I was a licensed Amateur. His response was: "I'm a Professional". I can still hear the capital "P", years later. Compare that to complaints being raised about my use of a club call-sign, or the publication of my podcast on-line, or the inclusion of an audio stinger in the local news I produce, or the inclusion of a flea-market segment in the same news, or a podcast I made about the use of an Iambic Key by Foundation Licensees. In each of those occasions either the regulator or the peak representative body of Amateur Radio in Australia, the Wireless Institute, or both, jumped in feet first, making pronouncements, issuing decrees or directives without ever actually contacting the person about whom the complaint was actually about. It seems that there must be a special hand-shake in order for your complaint to be taken seriously, that, or they're both running scared because I venture to make an opinion publicly. No, it can't be that, we have freedom of speech in this country - right? Anyone? I'm Onno VK6FLAB

Which antenna should I get first?

Sep 3, 2017 192


Foundations of Amateur Radio The other day I was asked about what antenna should you get as your first one. This question is pretty simple, but the answer is likely much less so. You might recall that I've pointed out that we can prove you physically cannot build the ideal antenna, so by definition all antennas are compromises. You might also find yourself being bamboozled by claims about how an antenna is the perfect match across all or many frequencies. The same is true for a dummy load where the purpose is not to radiate at all. With that in mind and armed with a healthy dose of scepticism, you can now go hunting for the answer. On my journey through this minefield of mysticism I went from a self built wire vertical on a squid pole with a 16 radial ground plane and an electronic antenna coupler, through a set of purchased single band verticals, a wire dipole, a wire delta loop, a Buddi-pole, a magnetic loop, a multi-tap vertical, and many others along the way. Some of those antennas were bought, others were built, several were given to me and some have been loaned by fellow amateurs. I should mention that the antennas I named were all for HF frequencies. On VHF and UHF, 2 m and 70 cm, the list consists of four antennas, I started with a simple vertical and in my car I use that almost exclusively. I also have two larger verticals at home, depending on what I'm doing I'll swap between them but for the past year I've had a 10 m vertical which also happens to be resonant on 2 m, so I can swap between HF and 2 m without climbing on a ladder. Building an antenna can be very rewarding but also very frustrating. Similarly, buying an antenna is no guarantee for success. This means that every environment is different and many combinations of antenna and location are doomed before you start. Essentially you have to start a process to find what works for you and your environment, a fixed location, or a car, portable, mobile or something else, in my limited experience there really isn't a substitute for trial and error. That being said, getting your hands on a balun and some wire is a good place to start. If you're looking for something that takes up less space, a vertical is often another way to get going. Currently in my car I use a multi-tap vertical. At home I'm playing with a 10 m vertical and a magnetic loop. When I set up portable on my own I'll use my squid pole vertical and if I'm with others I'll help string up as much wire as we can. At my local radio club I'll use one of several Yagi antennas and if I'm at a friend's place I'll use whatever they have plugged into their radio. This confusing mismatch of antennas reflects about six years of experimentation and I've not even mentioned the pile of failures sitting in the corner of my shack. Two more comments. Getting or borrowing an antenna analyser is a good idea and the amount of money you spend on an antenna is no indication of success. That's not really an answer, but it's the best I have. I'm Onno VK6FLAB

Amateur Radio is about Experimenting and Trying!

Aug 27, 2017 200


Foundations of Amateur Radio The other day I was browsing through the Amateur Radio Syllabus for Foundation Licensees, as you do, you know, when you're bored out of your mind, or in my case, looking for a topic to talk about. So, I came across this interesting point, if you want to look it up, point 2.2 of the Foundation Syllabus. It states that in order to attain your Foundation License in Australia you must: "Recall that an Amateur Licence primarily authorises the operation of an Amateur station for self-training in radio communications, inter-communications between Amateurs and technical investigations into radio communications." You might hear that and think, ok, so what's your point? Simple really. As an Amateur Radio community we have come to collectively understand that in order for you to do anything in the realm of building or research, you need to hold more responsibility and that if you're on the so-called bottom rung of Amateur-dom, you really are only a button twiddler, appliance operator and not much of an Amateur at all. It's funny really, since the Amateurs I know and consider to be my friends and peers, exist across the wide spectrum, from being licensed last week, through last year, through last decade onto before I was born, more than half a century ago, these Amateurs have one thing in common - curiosity. They like to explore, to investigate, to understand, to learn and to try stuff. Many of these Amateurs have a Foundation License like I do and their skill in exploring has very little to do with their level of license and everything to do with their approach and attitude. I know that I can just go about my business and ignore the noisy minority who continue to be derisive towards lesser Amateurs, but I think it's important to highlight that my personal experience does not match their vocal opposition towards those who hold different opinions, find different things interesting, bring different approaches and attitudes or continue to be excited by this hobby. I know that I often point out this element of nay-sayers, but I'd like to also point out that while they make noise, a much larger group of Amateurs continues to play and explore. A couple of years ago, when the ink on my license wasn't even dry, I was dragged, almost kicking and screaming, to a national Amateur Conference by a fellow Amateur and good friend. I resisted, but his insistence saw me pack my bags and head over to meet a group of people who share this amazing thrill that I experience with Amateur Radio on a daily basis. I'm immensely grateful for my friend and his badgering, and want to point out that if you find yourself surrounded by those who continue to tell you that you need to upgrade, that what you're doing has been done and failed, that what you're playing with isn't interesting, that what you're doing is wrong. If you find yourself in that place, then I urge you to find new friends in Amateur Radio, because we're not all like that, in fact, I'm pretty sure, most of us are not like that. It's just that the know-it-alls are good at telling you so and the quiet achievers just get on with it. Find a friend, explore an idea, try something new, visit a new club, or go on an adventure. Amateur Radio is and should be fun and if it isn't you're looking in the wrong places. I'm Onno VK6FLAB

How does PSK or Phase Shift Keying actually work?

Aug 20, 2017 199


Foundations of Amateur Radio Previously I've explained how Radio-teletype or RTTY works from a technical perspective. If you recall, it uses a technique called Frequency Shift Keying, or FSK to encode digital information. It does this by transmitting a carrier across two alternating frequencies, allocating one as a SPACE and the other as a MARK, or as a binary 0 and a binary 1. There are several other ways of encoding information and today I'm going to look at Phase Shift Keying, or PSK, which I find humorous, because Phase is spelled with a P, but it sounds like an F, which links the FSK and PSK together, but then I've always had a strange sense of humour. Imagine if you will a sine wave. It's the one you learned in high-school, nothing sophisticated about it, just keeps going up and down over time. Now imagine another one. Also going up and down over time. If these two sine waves are synchronised, going up and down at the same time, the difference between them is 0. If one of the sine waves is going up, while the other is going down, then the difference between them is 1. That is enough to give you a binary 0 and a binary 1. One of the sine waves is a carrier, so it's transmitted continuously, and the other is changed depending on whether you're sending a 0 or a 1. These two sine waves are said to be "in-phase" when they're both going up and down at the same time, and "out of phase" when they're going in opposite directions. This is how Phase Shift Keying works. And the simple example I gave is known as BPSK, or Binary Phase-Shift Keying. There are countless variations on this. For example, you don't need to have them going in completely 180 degrees opposite directions, you could go only 90 degrees, or even 45 degrees, which would allow you to encode more information across a shorter time span at the cost of less accurate decoding at the other end. You could play with the carrier and instead have the signal be compared to itself, making it more robust in some circumstances, or you could have multiple of these signals happening at the same time. You could change the amplitude of the carrier and allocate specific byte values to each combination. For example, one variation, an encoding method called "16-QAM" allows you to create 16 different signals, which equates to sending 4 bits at a time. Each of these have different advantages and disadvantages, trade-offs between speed, reliability, error detection, impact of polarisation changes in the ionosphere, energy efficiency, etc. You might be surprised to learn that these techniques are not only used inside Amateur Radio and PSK31, they're also used in Wi-Fi, Bluetooth, Ethernet, RFID and countless other places, like remote controls, hard-drives, tape recorders, satellite communications, mobile telephony, etc. If you get hooked, there's lots of maths that you can associate with all of this - if that floats your boat, but you don't need any maths to grasp how it works. Phase Shift Keying, one of the many Digital Modes that make our world go round. I'm Onno VK6FLAB

How does RTTY work?

Aug 13, 2017 152


Foundations of Amateur Radio The continued discussion in our community about Digital Modes got me thinking about what a Digital Mode actually is. At the most fundamental level, it's about encoding information into discrete chunks to exchange information. Morse Code is an example of a Digital Mode, made up from combinations of dits and dahs. If you change frequency whilst sending dits and dah's you invented RTTY or Radio-teletype. There are two frequencies involved, 170 Hz apart, where the lower frequency is the SPACE frequency and the upper frequency is the MARK frequency. If someone gives you a RTTY frequency, they're talking about the upper frequency. Instead of using Morse Code to send messages, RTTY uses 32 different codes, 5 bits, to exchange information. This isn't enough for the entire alphabet, with digits and punctuation, so two of the codes are used to swap between Letters and Numbers. Some radios can change frequency between the lower SPACE and upper MARK frequencies in a single transmission. This way of transmitting is called FSK, or Frequency Shift Keying. It's a lot like moving the VFO around whilst keying a Morse-key. Not something you'd do manually, since in Amateur Radio, this is generally happening 45 times a second. If your radio can't do the frequency shifting, then another way is to use Audio Frequency Shift Keying of AFSK, where instead of changing the frequency, you change an audio tone by 170 Hz. Without getting technical about how this works, if you've ever listened to Morse Code with a radio, you'll have noticed that as you change frequency, the sound changes. If you were to change the frequency of your radio by 170 Hz, the sound would also change by 170 Hz. So with that in mind, if you were to change the sound by 170 Hz, the receiver wouldn't care if you were changing the transmit frequency or the audio frequency, since it both sounds identical at the other end. Most of the time a computer is generating two tones, a tone for the SPACE, or lower frequency and a tone for the MARK or the upper frequency. It comes out of the speaker of the computer, which you feed into the microphone of the radio and your radio then generates a normal SSB signal that is experienced by the listener at the other end as a Radio-teletype. Pretty nifty and if you understand this, then most of the other Digital Modes in use today use similar methods. I'm Onno VK6FLAB

Qualifications for using a Digital Mode

Aug 6, 2017 138


Foundations of Amateur Radio Having a Digital Mode in your shack appears to be a special privilege, at least in some parts of the world. If you'd like to learn all there is to do with using a Digital Mode you need to pay attention and I'll share the secret, it won't take long. If you want to distinguish yourself as a Digital Mode Diva, you need to know that Morse, RTTY, FSK and PSK are digital modes and you must also remember that the bandwidth of a data transmission is dependent on speed and mode. At this point you've covered all the syllabus requirements for holding a Standard License in Australia in relation to operating a Digital Mode. If you want to climb the Mountain of Digital Mode Magic, you need to remember two acronyms, FEC or Forward Error Correction and ARQ or Automatic Repeat Request. You also need to remember four numbers, 31 Hz for PSK31, 250 Hz for RTTY, 730 Hz for Packet Radio and 300 Hz for FSK. And if you want to get really fancy, I should point out that there are several versions of each of these modes and different ways to implement them, so those numbers will change depending on who's teaching you. If I go on to tell you that a Terminal Node Controller or TNC is a black box with two audio leads, one for the microphone and one for the speaker and that you plug those into the appropriate sockets on your radio, you know all that is required to hold an Advanced Certificate in Australia for using a Digital Mode. If you don't want to blow up your radio, then you should also remember that there is a thing called Duty Cycle that will come to haunt you if you get it wrong. That's it, now you know everything there is to know about using Digital Modes. Actually, I'm lying. When you say the letter A on air you use the word Alpha. You're sending extra information so the other end has a better chance of understanding what you said. That's Forward Error Correction. And when you say the same thing repeatedly, like saying CQ, CQ, CQ, if you don't get an acknowledgement from the other end, that's Automatic Repeat Request. Now you really do know all there is to know about Digital Modes according to the syllabus for both Standard and Advanced Licenses in Australia. I'm Onno VK6FLAB

Mechanical Filters

Jul 30, 2017 307


Foundations of Amateur Radio The other day a whole new world opened up to me when I came across the idea that Voltage is the same as Force and Current is the same as Velocity. It all came about when I installed two mechanical filters into my radio. You heard that right, in my shiny solid-state radio, I added moving parts! The purpose of this was to improve the way the radio ignores unwanted signals and as a result has an easier time hearing what it is you really care about. The radio already has filters built-in, but mechanical filters offer a cleaner output with less distortion across a wider range of temperatures. Another way is to say that - mechanical filters have a much higher Q. Think of a pendulum swinging through oil, it's losing lots of energy for every swing and has a low Q. The same pendulum swinging through air retains most of its energy and has a high Q. The same is true for mechanical filters, less energy loss, better reproduction, better outcome for the things you want to keep and hear. So how does this then work? Turns out that our electrical theory with inductors, capacitors and resistors have mechanical equivalents, specifically mass, stiffness and damping. As I said when I started, Voltage is Force and Current is Velocity. It turns out that all the maths we use to design electrical filters can also be used to design mechanical filters and 1946 Robert Adler from Zenith did exactly that. This worked so well that in 1952 the Collins Radio Company started manufacturing them and today we still use them in many different radios. As an aside, you might be surprised to learn that the first filter that Robert Adler invented in 1946 was for a 455 kHz filter, which I could technically still use in my radio today, since the same Intermediate Frequency or IF is used. The mechanical filter - vibrating bits of metal - resonate with specific frequencies, much like a tuning fork does, but your radio deals with electrons, not movement, so the electrical signal is first converted into movement by a piezoelectric transducer, a piece of material that distorts when you apply an electrical field and when you use it in reverse, distortion creates an electrical field. So, you have a box with a wire at one end and a wire at the other and in between are two transducers and a bunch of mechanical resonators, much like a string of pearls on a necklace. I mentioned earlier that mechanical filters have a much higher Q. An electrical Q might range between 100 and 500, the mechanical Q in 1946 using steel was several thousand and in today's filters using Nickel-Iron alloys, a Q of 10,000 to 25,000 can be achieved. Without going into the maths, what is this Q really describing, other than the pendulum in oil and mechanical losses? One way to explain Q is to say that it describes the "goodness" of a resonant circuit, the higher the Q, the better the circuit. In our case, "goodness" means that it resonates better where we want it to and not where we don't want it to. Before you start wondering, why the letter "Q"? Turns out all the others were taken when K.S. Johnson was looking for a letter to describe the attributes of coils in 1920. Today we think of "Q" as Quality, but that's the cart before the horse. Anyway, back to Amateur Radio. If you look at a theoretical filter, you'll see a lovely curve that lets through the bits you care about and ignores the bits you don't like, but when you then start looking at the real world where damping and resistance come into play, you'll soon learn that there are all manner of ugly spikes on this lovely curve. A typical tuned electrical circuit will have artefacts, or distortions along the way, dipping down, instead of staying straight, or having an ugly peak when it should be smooth. This in turn results in something that you can hear, distorted audio where low frequencies are under or over represented and strange distortions occurring along the audio range. It also means that adjacent...

Contesting Protests

Jul 23, 2017 229


Foundations of Amateur Radio For the most part of my Amateur Radio life I've been an active contester. I have spoken about why I love contesting and why I think it's an important aspect of this amazing hobby. Today I want to talk about how contests are run, specifically how complaints are handled and how we could improve. I must at this time acknowledge that organisers are volunteers, just like many other Amateurs, giving of their free time, in this case, to manage and score a contest. Like much volunteering it's an invisible, sometimes thank-less and unenviable task, often akin to herding cats. To set the scene, a contest is an organised activity run by one or more people or groups that has a published set of rules, a set of aims and objectives as well as the mechanics of things like on-air conduct, point scoring, etc. A contester who decides to participate in a contest is expected to read the rules, abide by them and conduct themselves in an appropriate manner, that is, keep accurate logs, follow the log submission rules, etc. What happens after the logs have been submitted to the organiser is rarely spoken about. There is an assumption that the results are published, that complaints are handled fairly and in a timely fashion and that the outcomes are fair for all participants. In my experience, it's understood that if the rules don't specifically exclude a particular event, like say, using a Satellite contact during a VHF contest, those are fair game. Of course the response to such a thing is to update the rules to exclude that interpretation for the next contest. So, there are rules for the contesters, but are there rules for the organisers? What happens if they don't do their part? What process exists then? What if the results take over a year to be published, or you witnessed cheating, or you submit a log that has a score that differs from the results? If you bring that to the attention of the organisers, what is a reasonable response and how would you expect the issue to be resolved? In the past, any suggestion that there could be a place for a standard set of rules for organisers has been, in my experience, ignored or ridiculed with the notion that "We're all Amateurs here, stop taking things so seriously." In my opinion, that's not a reasonable response and it makes for uncomfortable interactions between contesters and organisers who are attempting to resolve a dispute in a civil way. In sailing, where the participants are amateurs, as in non-professional sailors, contesting is alive and well. Most weekends see a sailing race on a local water and protests are common. A standardised set of rules exist to handle disputes in a formal manner and raising a protest flag is the beginning of a set of steps that ends up with a ruling. In the case of contests in the Amateur Radio field, no such thing happens. As an example, I have personally raised a protest with a contesting organiser and have spent the past months attempting to get the results updated to reflect my actual score. I'm patient and persistent, I document every step, but ultimately I'm at the mercy of the organiser. Their decision to handle my protest is entirely arbitrary. In my opinion, this is not how contesting should work. It should be a fair contest between stations to apply the rules and come to a score. I've purposefully not named the contest or the organisers, since this is not specific to my protest. This is an issue that affects contests in Amateur Radio everywhere. What about looking at the sailing community and learning about their protest procedures? Are there contests that you participate in that have a formal complaints process and how well does it actually work? Have you ever had a contest protest that needed adjudicating and how did it work out? I'm Onno VK6FLAB

Our Amateur License System is Obsolete

Jul 16, 2017 255


Foundations of Amateur Radio Recently I made a point of coming up with three different names for License Classes in Australia. I proposed Low Power, Medium Power and High Power and then went on to suggest that this could also be a mechanism to update the framework that is Amateur Licensing in Australia. As it turns out, I'm told that this idea is mostly already active in the United Kingdom. My idea started as a response to an increasing clamour for more privileges for Foundation Licenses. These calls include demands for digital modes and more power. I understand this demand, though I don't particularly share it. I think that licenses evolve and the world in which they operate changes and that digital modes are an example of that. I have a much bigger problem with the way that licensees are using their level of license to look down on those who have "only" achieved their Foundation or Standard call. I have personally been told that I should get rid of my silly license and upgrade and it's unusual to meet a new Amateur who doesn't straight off the bat ask me why I haven't upgraded yet. I've seen the same behaviour toward Standard licensees and I think it's a fundamentally wrong attitude and approach to have. In my opinion this is a hobby for participants to do what they want to do within the constraints that they have. For some that means getting a higher level of responsibility, for others it means spending time doing deep learning and investigating the boundaries of their achievement. The notion that there are different levels of license is completely arbitrary and the idea that some are better than others is ludicrous in my opinion. Just because I have a Foundation License, doesn't mean that I am ignorant and just because others have an Advanced License, doesn't make them all-knowing or expert. If that wasn't enough, the boundaries between license classes are completely subjective, drawn from historic demarcations between VHF and HF, between Build and Buy and between Morse-Code and Not. These lines are getting so silly that they have become meaningless, to the point of absurdity. If I as a Foundation License holder can go to a shop and buy a Software Defined Radio, then update the software on that radio by using my skills as a programmer, I have fundamentally changed the way the radio operates, even-though I didn't once touch a soldering iron, or open the case. Our regulations have nothing to say on the subject, nor is there any sane way to police such an activity and nor should there be - this is an experimental hobby after-all. If I buy a radio in kit form and get it shipped to me, put it all together and turn it on, did I build something, or buy a commercially available radio? Where's the line between building and buying commercially available and what at the end of the day does it really matter? What is so special about the 20m band that prevents me as a mere Foundation Licensee to access that band and what is so amazing about digital modes that make it that I'm not allowed to use it, even though all digital modes are really just analogue audio and there is no certification, training or assessment related to digital modes for any class of license? My point is that the current licensing system is in my opinion obsolete, it's broken and the persistent baying from the sidelines by Amateurs who think that I'm demanding more privileges is getting tiresome. It's ludicrous to think that we should remain back in the 1970's, when Novice Licenses were introduced, perhaps while we're at it, should we go back to a spark-gap transmitter too? The idea that your enjoyment in the hobby is affected by my privileges is absurd to the level of being offensive and if you're threatened by my participation in the hobby, it seems to me that I must be making valid points. I don't want more privileges. I'm happy with what I have. What I want to do is make this hobby better, make it relevant, make it useful, make it accessible and...

Quick Fixes and Maintenance

Jul 9, 2017 162


Foundations of Amateur Radio There is a time for everything. Mostly when it's most inconvenient, like in the middle of a rare contact, or while you're running a pile-up like you have never done before, or while you're getting a multiplier during a contest. For two years I've been using an antenna on my car that on occasion has the ability to remind you of it's presence. In this case, there is a lead, a so-called wander lead, that runs from the base of the antenna to one of the various connectors that are spaced along the length of the antenna. In case you're wondering, it's an Outbacker antenna and it's the first antenna that actually worked on my car. This lead has two banana-plugs on it, and those are connected to the lead with little screws which have an uncanny ability to come loose when you least desire it. This ability of an item connected to your radio to make itself known to you is not limited to my wander-lead. I've seen the same behaviour on microphone connectors, interface adapters, baluns, speaker leads, power leads and the like. Often you cobble together a quick fix and off you go again, doing what you were doing. Only the quick fix turns into "the fix" and nothing is ever actually fixed. I've been to many shacks where a quick fix has been applied that lasted days, weeks, months, sometimes even years, but at some point it will fail again, perhaps with disastrous results, like letting the magic black smoke out of your radio - and if you're not sure what I'm talking about, ask a friend, but the smell is memorable and often there is a matching invoice to pay. During the week I did something novel. I remembered the last quick fix I did and instead of thinking: "I should do something about that", I actually went to my car, got out the antenna, pulled off the wander lead and actually fixed it, that is, got out a proper screw driver and actually tightened the screws. Mind you, as I'm thinking about it now, I have started to think about if I should solder the lead and remove the screws from the whole thing. I'll let you know how I go. The point I'm making, badly perhaps, is that the hobby we are engaged in, Amateur Radio, is about more than making contacts and building stuff, it's also about doing maintenance and thinking about how to make your station safer, more reliable, more usable and fixing those niggling little things that will come and bite you at some point in the future. Before I go, I should anticipate some responses which will be along the lines of: "Well, it was a quick fix, but it lasted for years." - good for you, you're a better fixer than I am. For the rest of us, have a good look at your station and think about some quick fixes you've applied. I know I'd prefer to complete the QSO with that rare DX station, rather than have them vanish and later learn that their microphone packed up mid-contact. I'm Onno VK6FLAB

What's in a name?

Jul 2, 2017 216


Foundations of Amateur Radio For a long time I've struggled with the way we differentiate between the different license classes in Amateur Radio. In Australia, the three levels of license are Foundation, Standard and Advanced. In the United States, they're called the Technician, General and Extra. In the United Kingdom they're called Foundation, Intermediate and Full. These naming conventions convey that more and more is gained as you progress though the ranks, but they also convey that you are incomplete if you're not at the top of the food chain with an Advanced, Extra or Full license. This naming convention is not universal. The license classes in the Netherlands are called the N or Novice Class and F Class, but generally they're referred to as the N and F classes and in Germany they're called Class A and Class E. Of course if you're making a complaint about what something is called then coming up with a new name is one of the first things that you'll be asked and that has stopped me from even beginning to make this observation out loud, let alone spend some time talking about it. Today I have a response to the question: "Well, if you don't like what it's called, what would YOU call it?" Here's what I came up with, if we're staying with three license classes, the three names I'd adopt are Low Power, Medium Power and High Power. The names are chosen to distinguish the power levels associated with the license which then also allows for another radical idea. What if everyone had the exact same privileges and the only difference between the licenses was how much power you could use? This in turn would require a person who moves from one power level to the next to learn specific skills. For example, RF safety with Low Power is completely different from High Power. Antenna efficiency has a completely different impact on a high power radio, than it does on a low power radio. Interacting with high voltages doesn't happen with low power but you can bet your RF burn that it happens with high power. EMR, or Electro Magnetic Radiation issues were the single largest hindrance to introducing more than 400 Watts into Amateur Radio in Australia. What if getting a High Power License came with a built-in EMR module and that the energy was built-into the licence system? If all licenses were the same, except for the power output, it would mean that all Amateurs could experiment with new modes and invent new things and the only hindrance to such experimentation would be the imagination of the person using the radio. We have artificial boundaries between the various classes of license which bear no relation to reality. In my opinion the boundaries hinder the progress of an amateur and external factors such as the changing of the solar cycle impact different license classes in different ways depending on when they got their license. Skills that are gained could be gathered as points or modules and could incrementally allow the progression to higher power. Of course, 100 Watts on 160m does not have the same impact from an EMR perspective as 100 Watts on 10 GHz, but I'm not advocating that the Low Power license is limited to 10 Watts across all bands, nor am I saying that a Medium Power License should have 100 Watts on every band. But there's no reason that the power level cannot be proportional to the amount of energy involved, rather than a fixed power output at the transmitter. For my money, lets ditch this Foundation, Standard and Advanced system and move to Low Power, Medium Power and High Power. Who's with me? I'm Onno VK6FLAB

Mobile experiments with high power.

Jun 25, 2017 203


Foundations of Amateur Radio A little while ago I had the chance to use a mobile radio with high power. I used it to learn about the coverage of our local repeater, but also to hear what the effects were when two local radios were both using the same repeater and high power at the same time. I made all manner of observations and wondered how much of what I observed was real and how much was a case of me adding two and two together and coming up with five. Immediately after I made those observations I received emails from around the globe explaining in great detail what was going on. Suffice to say that there was some disagreement among the emails, but overall they lead to a few new things that I'd not considered. One comment was that the two radios, not quite side-by-side, but in two cars nearby was similar to the operating environment of a repeater, that is a receiver and a transmitter sitting in close proximity. Initially I didn't cotton on to the analogy and it took several readings to understand, but the outcome is that, as I suspected, the receiver is being overloaded by a local transmitter which is putting out a big signal that is overwhelming the electronics in the receiver, something that a repeater deals with every time you key it up. The short version of this is called de-sensing. I'm still reading about how it exactly works on the inside, something for another day. In a repeater the issue is dealt with by filtering the outgoing signal and filtering the incoming signal, making sure that only the desired information makes it to where it needs to go. Two random radios bolted to two cars don't have any such filtering and no way to reject the unwanted signals. Adding filters to both cars might fix the issue, but then we weren't trying to fix anything, just to learn what was going on. Another thing I learnt was that FM receivers don't need an AGC, since the volume of a signal is related to how much it deviates from the central signal, not how much signal there is, which is why the microphone gain setting on your radio determines the volume, not the level of power. To be clear, enough of your signal needs to get to the other end for it to work, but after that, you're just wasting electrons. If you need a visual for that in FM the height of the signal doesn't matter once it's high enough, the wobble determines how much volume there is. In AM, there is no wobble, the height determines the volume. Incidentally, if not enough of your signal gets to the other end, then your weak signal might be overtaken by another signal and the so-called "FM capture effect" happens, where the low signal gets effectively rejected in favour of the higher one. Interestingly Amateur Radios can have an FM AGC which can be used to determine the signal strength, which makes your S-meter behave more like it does on HF, but if you recall, an S-meter is really a guess-o-meter since every manufacturer has their own "standard" and two radios are unlikely to experience the same S-level for the same signal. Don't misunderstand, I'm not maligning the S-meter, just pointing out that your S-5 and my S-5 are unlikely to be the same. So, the more I peel away from my little mobile experiment, the more I unearth in the wake of the experiment. Such is the joy of Amateur Radio. Be curious, investigate and learn. I'm Onno VK6FLAB

Magic and Curiosity in Amateur Radio

Jun 18, 2017 196


Foundations of Amateur Radio You know you've been at something for a while if you come across a topic that you want to dig into and discover that you already covered it in great detail a year ago. For me that topic was the "FM capture effect", which I covered in great detail a while back - the research says: "This happens, we know it happens, it happens under these circumstances, but precisely how, we're not sure." I finished off with a quote by Arthur C. Clarke who wrote in 1973: "Any sufficiently advanced technology is indistinguishable from magic." -- by that definition, Amateur Radio and the "FM capture effect" is clearly magic. For me Amateur Radio is about the constant quest of learning, the ongoing pursuit of explanation and understanding, the relentless curiosity that burns a hole in my mind waiting to get filled with information and knowledge about anything and everything. In that same environment I am the holder of the beginner's license in Amateur Radio and that is the cause for some members of our community to scoff at my skills, to demand that I upgrade, to ridicule the level of licence that I hold and to brandish their higher level certificate of proficiency as a weapon against my meagre understanding of this hobby. How is it possible that this irrational belief that one license is more valid than another can exist in a world where something as basic as the "FM capture effect" is not understood, not documented, not explained and not taught to those holding the summit of knowledge, the highest level of Amateur License? I've been a student all my life and truth be told, that's true for most people I meet. There are a few people who know everything already, but the rest of us are able to understand that learning is a continual process. The level of license you hold has nothing to do with your ability to learn, your ability to understand or your ability to be a higher class of human. A high level license is a privilege to incur a higher level of responsibility and acknowledgement that at some level you're able to walk and chew gum at the same time. Clearly for some it's the ultimate expression of their superiority, but for the rest of us it's a token that affords us extra access to radio spectrum and technologies. One reason I'm raising this is because if you're a new entrant to our hobby, you might be confronted by Amateurs who demand that you update your license at their insistence, rather than your interest, which can lead to you leaving our community which is a regrettable and undesirable outcome. Another reason I'm raising this is because there are many things in Amateur Radio like the "FM capture effect", phenomenon we know happen, but have little understanding about. These things have implications far beyond our hobby. For example, the mobile phone in your pocket, or the laptop on your knees or the wireless headphones on your head, all use technologies that are subject to the "FM capture effect" and understanding and research in our hobby can and will help the wider community. So, don't let your lowly license deter you from learning, from participating, from being curious and researching things that interest you. Who knows, one day you'll add to the body of knowledge that we call Amateur Radio and we'll all be better off. I'm Onno VK6FLAB

Using an Alex-Loop, very satisfying ...

Jun 11, 2017 148


Foundations of Amateur Radio The quest for the perfect antenna is likely to be one of the things that you'll carry with you during your entire Amateur life. In the past I've explained how the perfect antenna cannot exist and that the amount of variation inside just one antenna is infinite, so there is lots to choose from. One of my friends loaned me an antenna called an Alex-Loop. It's a so-called Magnetic-Loop Antenna and while the physics of the antenna is fascinating, I'm not going to go into it today. Suffice to say that there are hundreds of articles on the subject on-line and if you do dive in, read at least 20 or so before you decide that you understand how it works or how to build one. Until I used the Alex-Loop, I'd been using antennas that are set-up for a single band, or ones that require switching between bands, or using long-wire antennas with an SGC antenna matching unit. I've also used so-called antenna tuners, a topic worthy of discussion some other time. When you use your radio to pick a frequency, so too do you pick an antenna setting with a magnetic loop. In this case, the user-interface is a knob that changes a variable capacitor to make the antenna match between 7 MHz and 30 MHz. As I said, I'm not going into the physics of this, but the outcome of turning the knob is that at one point for each frequency, the sound coming from the radio will peak. As you turn the knob on the radio, you also turn the knob on the antenna. The two go hand-in-hand and the experience is a pretty satisfying one. No need to switch bands, get out of your operating position, change the band on your antenna, or switch a coax switch to another antenna, or transmit to make the antenna matching unit do it's thing, or to peak the antenna tuner, nothing like that, just a simple turn of the dial will get you to where you need to go. The reason I'm discussing this is because it's the first antenna I've used, and I have played with hundreds of them, that is able to match the user experience of turning the dial on your radio with turning the dial on your antenna. So far, operating from my QTH, where the noise is an abysmal S9, I managed one contact, which I have to tell you was great. It wasn't earth shattering, not even that far or noteworthy, but as contacts go, it was very satisfying. Hopefully in the not too distant future I'll be able to find some time and go to a more RF quiet location and have some more fun. I'm Onno VK6FLAB

Getting an elusive contact ... fly-fishing style.

Jun 4, 2017 170


Foundations of Amateur Radio There's a phrase that I use quite often, "Get on air and make some noise!" In terms of Amateur Radio that makes people think that I mean that they should turn on their radio, pick a band and call CQ, for hours. I can tell you now, if you're a QRP station, this is going to be a frustrating experience unless you're lucky or happen to be located in a place where other Amateurs want to talk to you, like an uninhabited island, or a low-tide reef, or some other place on the DXCC most wanted list. I liken operating a low power or QRP station to fly-fishing. To get a fish takes patience, skill and persistence. Would you start fishing in an industrial sewer in the hope that you catch something, or would you attempt to learn something about the fish that you're trying to catch, before seeking out its hiding place and throwing out a bait? Operating your Amateur Station should be more of the baiting and less of the industrial sewer. So what does this look like in your day-to-day operation of your station? Well, for starters you'll need to figure out where all the other Amateurs are. You can do that by listening for other stations, or by finding automatic beacons and seeing if you can hear them. That takes care of the first problem, is it at all possible to catch anything here? The next challenge you're faced with is when to find these stations. You'll need to do some reverse investigation. If you're trying to contact the other side of the globe, it's likely that the station you're looking for is going to be asleep when you're awake. So, calling a station during your lunch break is likely to mean that it's midnight over there. So, pick a time when they're likely to be awake, the beginning or the end of their day, which happily coincides with the grey-line, when the sun is just on the horizon, when radio propagation goes through some magical transformations. If you call on a Wednesday, it's likely that they're also in the middle of their work week, so think about how to plan for this. If it's a public holiday, check to see if they have one too, or plan for operating during the public holiday at the other end. If there is a large Amateur Radio contest at the other end, you might find that your station is desirable as a contact, or the opposite might be true, so check that out. Of course, I'm not able to cover all the variations of this and it will be specific to your station, so spend some time planning and learning about what a contact might look like. Now, if you take this advice to the extreme, you'll end up never getting on air and calling CQ, which means that you'll never get a serendipitous contact, nor will you capture the exception where an insomniac operator is trolling the bands to talk to someone, which would be a shame, so, do your homework, learn about when and where to operate and in the mean-time, get on air and make some noise! I'm Onno VK6FLAB

What if the Radio Spectrum was a data souce?

May 28, 2017 157


Foundations of Amateur Radio The evolution of Amateur Radio is a constantly changing landscape. I've previously described the transition from spark-gap to surface-mount and the ongoing progression of inventiveness that brings this amazing hobby together with the leading edge of science and technology. If you think of software defined radio as a linear increment on the radio scale you'll end up where we see some of the manufacturers today are placing their bets. You'll find a radio that has knobs and buttons like a traditional radio, but behind the scenes there is a computer and a new way of accessing the radio spectrum. A little further along the scale is the proverbial black-box, often with a single button to power it on, a few connectors for antennas and a network connection to get information to a computer. The software on the computer often attempts to resemble a traditional radio with similar controls and the combination of the box and the computer with the software running makes for an Amateur station. If you have no rules for how the user must interact with the radio, you might come up with interactive waterfall charts that display the radio spectrum as a graph, showing frequency along the horizontal axis, time across the vertical axis and colour as a measure of signal strength. Each of these experiences are attempting to achieve the same purpose, making the radio spectrum available to the station operator. If you completely decouple the concept of radio from this and look at the spectrum as a source of data, then processing that data, often in real-time, becomes less constrained by the limits of our current perceptions of how a radio works and moves into the realm of data science. To give you a concrete example, if you've scanned a photo on your computer and are confronted by little dots of dust, there is software available to remove that dust and re-create the image in much the same way as the original might have been. The process is called noise reduction. That same process could also be used to process radio spectrum, or audio. There are many concepts that exist outside radio that can be used in this new world. You could do live analysis of the bands, determine which signal had the best chance of getting to the intended recipient, you could decode information spread across multiple bands, with bandwidth use that could be measured in gigahertz, rather than kilohertz. With the limits of your mind as the only barrier, what other inventions might be arriving at our doorsteps in the near future? I'm Onno VK6FLAB

The evolution of our hobby is now ...

May 21, 2017 148


Foundations of Amateur Radio The hobby that we call Amateur Radio has been around for over a century. During that time we've seen it evolve from capacitors, inductors, through valves, then diodes and transistors, through to integrated circuits, chips and surface mount components. Along the way we collected a vast body of knowledge and experience which combine to make the hobby what it is today. You might have noticed that the progression of our hobby didn't stop with surface mount components, it's still evolving through software and the next frontiers are already tentatively being explored and offered for sale to curious amateurs. In my day job I'm a software engineer and I adopted Amateur Radio as my hobby of choice because it was technically diverse, had a rich history, a large community and had little to do with my day to day pursuits in computing and information technology. How wrong was I? This morning I started writing code to visualise audio, specifically in my case to make a video version of this weekly segment, but also to experiment with how we as humans use our senses to decipher information. As I was buried inside the decoding of audio it occurred to me that what I was doing was the equivalent of soldering together a circuit for the purposes of learning more about some aspect of my hobby. This in turn made me realise that as we dive deeper and deeper into the software defined radio universe, more and more of what we as individuals can do will be based on computers, algorithms and maths. On the face of it, this is an enormous shift in perspective, but I'd hazard that it's no different from moving between a spark-gap transmitter and an AM transmitter, or moving from AM to SSB, or the introduction of transistors. Each of those changes now look pretty small with hind-sight, but at the time that they occurred their impact must have been immense. I made contact with the software defined radio community a few weeks ago and in between my work I'm slowly beginning to explore this new universe that is beginning to unfold. Of course, as this evolution happens, while we're in the middle of the transition, as-in right now, there'll be discussion about the difference between digital and analogue, between hardware and software, about the benefits and pitfalls, no-doubt mirroring prior discussions that have been had across the past generations of amateurs. A new dawn has come and the future is here, come and join the fun. I'm Onno VK6FLAB

Things you can learn from a new operating environment ...

May 14, 2017 209


Foundations of Amateur Radio The other day I had the fortune of using a club station with an Advanced License whilst mobile using more than my usual 5 Watts. I was driving in convoy away from the main local 2m repeater and was interested in finding out what the coverage might look like and how high power might make a difference. When I say high power, that's 50 Watts FM on 2m. I learnt several things during my journey. First of all, line of sight is still true, even with more power, but there is more margin for error. Little obstacles that would cause a 5 Watt signal to be absorbed before it got to the other end are all but invisible with full power. Don't get me wrong, a hill is a hill and a radio signal won't go through it, but trees, houses, and all the other little things we humans build on the planet each obstruct a little bit of signal. Higher power gives you more margin and less effect on the resulting audio. The next thing I learned is that two cars, travelling in convoy can overwhelm each other with power. The way you experience this, is that the other car starts talking, and all you hear is mush. As they drive away from you, at say a traffic light, their signal becomes clearer, to the point where it's back to normal. The way it sounds is almost as if the signal to noise ratio is being adjusted, more signal, less noise as the distance increases - a very strange sound to hear. As it was explained to me, the phenomenon relates to the receiver being overwhelmed by the very strong signal nearby. I'm guessing that the AGC, Automatic Gain Control is reducing the sensitivity of the receiver, to compensate for the strong transmission nearby, which in turn means that it is unable to hear the repeater which is relaying the same signal on the receive frequency. As the distance from the strong transmission increases, the AGC compensates, increasing the gain, thus making the receiver able to hear the repeater. There wasn't the opportunity to experiment too much, being in a moving vehicle, but I wonder if changing the AGC setting would have made a difference. I suspect that there is more going on than just the AGC, since the signal from the nearby transmitter, the one in the other car, is still exciting the receiver, even if the gain is being adjusted. I suspect, but don't know for sure, that theoretically, I would have been able to hear both signals, the outgoing one from the other car, even though it's 5 MHz off frequency and the incoming signal from the repeater. Likely there was a minuscule delay between the two, perhaps even to the point of suppressing each-other. Another question that comes to mind is a phenomenon called the "FM Capture Effect" as well as the so-called "near-far problem" and I'm wondering if this is another aspect of what I was hearing and if we had a local AM repeater, would it exhibit the same behaviour? Now, as you might have guessed, there is very little in the way of research in my comments here, but that wasn't the point of what I'm talking about. The point was that a slightly new operating environment introduced me to concepts I'd never considered, never even really knew about, other than in a theoretical sense and I was able to actually see, well, hear, this in real life. Given my track record with over 300 different episodes, you can take for granted that I'll be digging deeper into the experience to see what I can learn and to see if my initial observations bear any relationship to reality, or if I'm adding two and two together and coming up with five. I'm Onno VK6FLAB

What to say on-air?

May 7, 2017 152


Foundations of Amateur Radio There's a confession I'd like to share with you. Chatting on air is something I rarely do. When I'm working distant stations, so-called DX, my typical exchange is: AB0XYZ, you're 5 and 9. If the station has some questions to ask, I'll answer, but often times there is no conversation and I'll move on to the next one. Some of that can be explained by my initial training as an Amateur. I started working lots of stations in a contesting environment. I took to it as a duck to water and never looked back. No doubt I have lots to learn and I cannot guarantee that my callsign recollection is as good as I think it is, not to mention being able to detect an incorrect callsign, since I still have little knowledge in which callsign prefix, the first part, belongs to which country. Another explanation is that I'm often QRP and just very happy to be able to make the contact in the first place. I hear stations on-air having a great chat, a so-called rag-chew, but I never seem to find something interesting to say or relevant story to share with a stranger. Sure I can talk. As you might have gathered from listening to me here, I'm never short of something to say, or an opinion to venture, but being sociable is not one of my stronger traits, never has been. A few of our local Amateurs have a tendency to tell stories that go on for so-long that they time-out the local repeater, to the point where one repeater has been set to a 15 minute time-out just to cater for verbose exchanges. I immensely enjoy the stories, but often find myself wondering what I might contribute without sounding like I have tickets on myself. I recently was asked by a new Amateur what to talk about. Their daily commute is a 30 minute car ride to and from work and chatting on the repeater seems like a logical thing to do, but they asked me what to talk about. Stuffed if I know. Seriously though. The very first part of chatting is to actually turn on your radio. The next part is telling others that you're there. Then when they do, ask what they've been up to and before long there is a conversation under way. The funny thing about all this is that while I'm pretty quiet when it comes to being on the local repeater, I do host a weekly 'net for new and returning Amateurs and when asked I'm more than capable of standing my ground and venturing my opinion. Perhaps I just need to practice more and perhaps if you find yourself at a loose end on a topic of conversation, feel free to make fun of me or to raise a topic that's something I've talked about. Who knows, we might both learn something. I'm Onno VK6FLAB

Amateur Radio Community Standards

Apr 30, 2017 184


Foundations of Amateur Radio The Amateurs Code, originally written in 1928 has been quoted for almost a century. A Radio Amateur is Considerate, Loyal, Progressive, Friendly, Balanced and Patriotic. There is something almost romantic about that, but in my short life as an Amateur I've been exposed to much that leaves that as just a sentiment, rather than a social code. I'm not alone in that. I have numerous emails from Amateurs around the planet who share their negative experiences, often being bullied by self-proclaimed experts with an axe to grind. Our 1928 Amateur Code brings with it a sense of decorum, etiquette, but other than some true Gentlemen I've had the pleasure to meet, there are aspects about our community that just don't translate into today, even if the Amateur Code could lead the way. Our community of Radio Amateurs represents an opportunity to engage with society, to attract new blood, to include new ideas and to lead the way in community engagement. As one path towards growth of our hobby we have started talking about STEM, Science, Technology, Engineering and Maths as one way to relate to a wider community. That's a great sentiment, but I think we need to do some housekeeping before we embark on that journey. Amateur Radio is steeped in tradition. We use quaint terms such as OM, Old Man to describe each-other, YL, Young Lady to describe women in general and XYL for wives of Amateurs. We have a thing called a "Gentleman's Agreement" and we generally refer to Amateurs as He and Him. By doing that we've essentially limited our audience to 50% of the global population. We alienate women before we even start to engage them and when we do have female participation we get Facebook posts full of sexual innuendo, or outright sexist comments, not to mention the girlie pictures spread around the globe, sniggeringly exchanged as contact QSL cards. On air we alienate women, make disparaging or sexual comments or express our amazement that a mere female could achieve a license. What are we, pubescent boys? Is that the best we can do? The irony is that we as a community rarely discuss politics or religion. It's just not the done thing. In general day-to-day exchanges we use inclusive language. In our workplace we are sensitive to people who are different and in our laws and rules we champion equal rights for all humans, be they men, women, gay, straight, yellow, black, purple or intersex. Why is our Amateur language not inclusive in a hobby that is based around communication, where Amateurs clamour to work a pile-up on a rare DX station in some war-torn part of the globe, where science and rational thought are expected and where an Amateur Code written in 1928 encourages us to be Considerate, Loyal, Progressive, Friendly, Balanced and Patriotic? I think we need to take a long hard look at ourselves before we start going into schools and sharing what our amazing hobby is about. I'm Onno VK6FLAB

Beauty is in the eye of the Beholder

Apr 23, 2017 149


Foundations of Amateur Radio There is something magical about getting a new radio. I remember it well. Fondly even. I had done the research, consulted my bank account and picked my radio. It arrived in a courier delivery and I sat at the kitchen table, opening the box and marvelling at the parts that made up my first purchase as a radio amateur. I'd joined my local radio club a month earlier and proud as punch I took my shiny new box of joy to the club and showed it off to anyone who came near. I vividly remember one member's first comment: "Wow, that's an ugly radio!" I was heart broken, insulted, confused and didn't quite know what to do with that experience. My radio was beautiful, tiny, special. It was just what I wanted, it wasn't ugly and besides, it was mine. As irony would have it, several months later I saw their radio and thought that it wasn't something that I would like to bring home. Fast forward six years. The other week, I went to a local Ham-fest, it's a place, often a local hall with tables around the edges stacked full of an amazing array of stuff, where amateurs come together to meet and exchange their obsolete junk, uh, surplus equipment. It's not uncommon to arrive at a Ham-fest with one box and to leave with two. Among the tables and amateurs I was introduced to a new radio. I looked at it and in my head I thought: "Wow, that's an ugly radio!" - fortunately I managed to keep the thought to myself and instead asked the amateur who was showing it off about how it worked, how they liked it and what it cost. The amateur was excited to share their thoughts and I learned something from the exchange. When I got home I searched the 'net for some more information and found that this particular radio was more than it appeared and that my initial dislike of the visual translated into an interest that might yet see me as the owner of that radio. I know you're busting to ask which radio and which amateur, but I'm not here to advertise any particular radio, just to observe that beauty is in the eye of the beholder and that things can change once you know more. I wish I had those words to share with the first person who told me that I had an ugly radio, but I'm pleased that I have them now. So, beware, ugliness is an emotion, not always accurate and if you experience it, bite your tongue and learn something first. I'm Onno VK6FLAB

An Amateur Radio Code of Conduct

Apr 16, 2017 269


Foundations of Amateur Radio The Hobby of Amateur Radio is a curious mix of technology, rules and people. If you're new to this you're likely to find yourself being swept up in the scale of the experience and more than I think is appropriate you'll find yourself at the pointy end of a barb by another member of the community. It's taken me over six years to begin to understand what is going on that is causing this. Let me start by saying that there is no place for bullies in this society. Correcting a mistake is one thing, but causing interference, transmitting insults, abusing people on air, ignoring new-comers or using social media to vent is just not appropriate. Bullying aside, after looking at posts on social media for a while, it occurred to me that much of what lies at the root of this behaviour is a fundamental mismatch between how licensing is achieved today, compared to how it was achieved historically. I see regular references to the type of examination. For example, historically examinations were conducted using full written exams, where today we are likely to use multiple-choice methods and even those are being reviewed. It occurs to me that historically, the process of becoming a licensed radio amateur was a slow and steady process, infused with deep contact with an existing amateur, regular training, exposure to the community, on-the-job training, interspersed with study and then finally an examination. Today, the process is more likely to be a much quicker affair, with initial exposure to the hobby, a visit to the local training facility, either face-to-face, or on-line, followed by an examination. If we assume for a moment that both examinations are the same in terms of assessment, and I know that in and of itself is controversial, what else is different between these two processes? The answer is the deep contact while learning. In the United States this is referred to as Elmering, in Australia it's called Mentoring and it isn't the same as it used to be. Today there is mentoring going on, lots of it, but often that's after someone has actually received their credentials as a licensed operator. We assume that the examination prepares us for the hobby, but actually, the examination just prepares you for the law. That is, holding a certificate of proficiency means essentially that you are now legally aware that you can create interference and that you are liable if you do so. As I said, the deep contact during the learning process is different. That deep contact exposes a new amateur to the unwritten rules and customs that form part of the community of radio amateurs across the globe. For example, we use Lower Side Band or LSB below 10 MHz and Upper Side Band or USB above 10 MHz. There is no technical reason, just historical ones, that make that this must be so. There are many, many such un-written rules about amateur radio. Often they are referred to as the "Gentleman's Agreement" - and I'll leave aside for a moment the gender issues related to that notion. This so-called "Gentleman's Agreement", is not written down, it's passed on from amateur to amateur, or assumed to have been magically acquired by the process of osmosis. So, a newly minted Amateur, truth be told, I'm one of those, steps into the stream and gets swamped by rules that appear from no-where and instead of getting chapter and verse on how to learn, the amateur gets insulted and ostracised. It is clear to me today - more than it has ever been - that old hams die hard. They are responsible for their legacy and if they want to maintain the hobby in their image, they're required to be inclusive and assist new amateurs, rather than insult them and drive them away. I know that there are many wonderful amateurs in our community who do just that. However, the noisy ones just want the new amateurs to get off their lawn and go and play with something else, preferably not in their patch. I have no doubt that I'll get flurries of people who...

What is SOTA?

Apr 9, 2017 206


Foundations of Amateur Radio One question I get asked regularly is: "What's the point of Amateur Radio?" Today I'm going to begin to answer this perennial question. As you know, this activity is a hobby, something you do for your personal enjoyment. People get pleasure from a vast range of undertakings and if you combine multiple such adventures into your life all the better. Amateur Radio is a hobby in and of itself, but it's also an enabling hobby. What I mean by that is it often can act as an excuse to do something else - under the guise of being Amateur Radio. For example, you can use an activity called SOTA to add some fun into your life. I've spoken in the past about SOTA, Summits On The Air. It's a way to enjoy being outdoors and climbing across the globe, as well as an excuse to participate from the comfort of your shack to encourage climbers and even as an unlicensed radio enthusiast, you can also participate. SOTA started in 2002 with the publication of the General Rules which outline all that the community expects and needs from you if you participate. In the intervening years the document has grown to 23 pages and I confess I was not looking forward to reading it all and truth be told, I've not yet digested the finer points, but I will before I next climb up a mountain. Don't get me wrong, it's not an onerous document, it's laid out well, describes precisely what's involved, how it's structured, who to ask questions of, what code of conduct is expected and what constitutes a valid SOTA activity. As I said, before I next climb up a mountain - more precisely, in SOTA terms - it's a prominence, something sticking out of the earth. Before you start gathering maps and looking at tall rocks, a prominence isn't just about how tall it is, but also how close other peaks, there's a whole definition of this idea, but the SOTA volunteers have done all the work, so you don't need to get technical to get on-air. There's rules about getting to a peak, about being there, about the environment, about how to use callsigns and the use of cars and other things, so before you get yourself into strife, like I did, read the rules. There's three kinds of participants, an Activator, someone who climbs up the mountain, gets wet, gets snowed in, gets hot and sticky, eaten by mosquitoes, breaks stuff and does all the hard work. The second type of participant is the person in the shack behind their radio, on the listen-out for new activations, making contacts, logging them and gathering points. The final group of participants is the Short Wave Listener or SWL, who logs contacts, showing both sides of the communication, both stations heard, etc. An awards system exists for all three participants. SOTA is a global activity. On the face of things it might seem daunting and my highlights of the notion that there are rules should not deter you from actually participating. The rules are to ensure that people don't get into trouble and die, to make sure that everyone has a good time and to deal with disputes as and when they arise. Many resources about Summits On The Air can be found online, but your starting point should be http://sota.org.uk where you'll find a welcoming and active community of enthusiasts who also like being on-air and making noise from weird and wonderful locations on top of big rocks. The point of Amateur Radio is to find something that you enjoy doing and making it a shared experience by incorporating your radio. A bit like Mark Twain said: "Golf is a good walk spoiled", SOTA is a mountain climb enhanced. I'm Onno VK6FLAB

Adding a stroke to your callsign ...

Apr 2, 2017 166


Foundations of Amateur Radio To sign or not to sign, that is the question. Last week I spoke about operating with low power, or QRP which sparked a lively discussion which evolved into a conversation about adding bits to your callsign to indicate some extra information. For example, some stations will add stroke QRP to their callsign when they're operating low power when others don't. Other examples are adding stroke Portable or stroke Mobile. Let me start by saying that I'm not familiar with the rules in countries outside Australia, but I'd be surprised if they're much different, since callsigns follow a global standard, but check your local laws before you start getting on-air to make noise. In Australia the rules, the Radiocommunications Licence Conditions (Amateur Licence) Determination 2015, commonly referred to as the LCD has nothing to say about any such addition to a call sign. There is no mention of low power operation, mobile operation, marine operation or any such thing. The reference to portable operation discusses how long you're allowed to operate a portable station without notifying the regulator. So, from a legal perspective, there is no such thing as a stroke anything. So where does this addition of stroke QRP, or stroke Mobile or any other variation come from? The regulator maintains a website that has a page called "Amateur operating procedures" which "can help prospective amateur operators". It details types of transmissions, discusses code words like QRP and has one set of comments about adding something to a transmission when operating mobile or portable. It suggests that you can say something like: This is VK6FLAB operating portable on Wave Rock, and if you're operating outside your state, suggests that you might shorten that to VK6FLAB/5 when operating in South Australia or VK5. So, there is no such thing as stroke Portable, stroke Mobile, stroke QRP and the only suggestion from the regulator is that you indicate that you're mobile or portable and help by indicating your state if you're not operating within your home state. In the past few years I have signed with VK6FLAB/QRP but after realising that this causes much confusion in logging, I have stopped doing it. These days you might hear me say that I'm operating QRP during a CQ call, to help other stations a little, but I've often found that it's really not worth the extra breath. I'm Onno VK6FLAB

Life's too short for QRP...

Mar 26, 2017 159


Foundations of Amateur Radio A phrase I hear regularly is "life's too short for QRP" and today I think that it's appropriate to start a conversation about that sentiment. When propagation is poor the high-power amplifiers get on air and use it to prove that you need power to get out and about. Far be it for me to deny another amateur the pleasure of working a thousand stations at the same time, a so-called pile-up. It's a thrill. I've done it during contests. It's fun. You call CQ and the biggest problem you're faced with is deciding on which station to pick. In the past I've mentioned that I've made a contact with Cuba, about 18,000 km away using 5 Watts. Over the weekend I managed just under a third of the distance, Perth to Tuvalu, 7,000 km with a wire and 5 Watts. You could take away from this that I like bragging about my contacts and it's true that I'm proud of having achieved those things, but that's not actually what I want to talk about. Amateur Radio is a lot like fishing. You can go out and throw a stick of dynamite into a pond and pull out all the fish, or you can stand up to your armpits with a reel in your hand casting a fly to catch a fish. Operating QRP is like fly-fishing. It takes practice, patience and perseverance. Of course it's not for everybody, but then neither is fly-fishing. If you hold an introductory Amateur Radio license like I do, the rules of engagement restrict how much power you're allowed to use. For some this restriction appears to inhibit their ability to enjoy the hobby. This podcast started life some six years ago precisely because a new entrant was expressing their need for more power. My contact over the weekend wasn't particularly earth shattering. It was made with a minimum of equipment, a wire antenna on a squid-pole strapped to a house, simple radio, running off a battery in preparation for a contest that was happening the next day. The thing to note is that it happened on 40m, using 5 Watts and the distance was twice the maximum distance within my own country. This means that any amateur who is starting out can achieve the same thing. It means that you might need to review your assumptions if you think of a 4,000km distance between stations as a hurdle that cannot be overcome. The take-away should be that while QRP is not for everyone, it's a perfectly valid way of enjoying the hobby and smelling the roses along the way. In case you're wondering, yes, I was wearing a grin from ear to ear after making my contact. Better still, I didn't have to kiss any fish. I'm Onno VK6FLAB

What is a resistor?

Mar 19, 2017 203


Foundations of Amateur Radio Last week I was casually asked "What is a resistor?" Now if you're into electronics like many radio amateurs, you'll instantly have a picture of a little blob with two wires with pretty colours painted on the outside, the size of a grain of rice and if you're not into electronics, you now know what a resistor looks like. Before I talk more about resistors, I'm going to talk about a stick. If you pick up a stick and poke something with it, some interesting stuff is actually happening. You move your hand at one end and the other end moves at the same time. Obvious right? It's a stick. On a molecular level something else is happening. The atoms under your hand inside the stick move back and forth with your hand as you move it. The atoms next to those atoms do the same thing. The atoms next to that, all the way to the end, also do the same. Now you likely have a picture in your mind of a solid stick. On a molecular level, this isn't solid at all. Instead of a solid stick, imagine having a row of ice-cubes with a little space in between each one being bumped by the previous ice-cube. The ice-cube closest to you moves with your hand, the one next to that gets bumped, all the way to the end. With ice-cubes there is a noticeable delay if the gaps are visible, but the delay gets smaller and smaller if the cubes are closer and closer together. In an electrical wire a similar thing is happening. You might have a picture in your mind of electrons travelling from one end of a battery, through a wire to the other end of a battery. Except that's not what is happening. While electrons do move, very slowly, it's called the drift velocity, think centimetres, or inches per hour, turning on a light is instant. It's instant because each atom affects the one next to it, which does the same to the one next to that and so-on. While not exact, this happens roughly at the speed of light. This is beginning to look a lot like a stick. Push at one end, something happens at the other end, almost immediately. Instead of ice-cubes, but in much the same way, we're actually moving an electrical charge from one end of a wire to the other. It takes energy to keep a charge moving along a wire. The amount of energy used is the resistance of that wire. Not all materials act in the same way. Some, like silver or copper, use little energy or have low resistance, while others like carbon, use more energy and have high resistance. You'll find resistors made in many different ways of various different materials. Each one is made for the specific purpose of using a defined amount of energy to pass along a charge. There are resistors made of carbon and of thin film of conductive material sometimes with laser cut paths to make them appear as a long maze of conductive material and of very thin wire, tightly wound together. This kind of wire resistor has a side-effect in that a tightly wound coil like that has some properties that we use in Amateur Radio, we often think of these kinds of devices as inductors. But that's another story for another day. As a side note, I started using coulombs, joules, volts, amperes and ohms to explain this, but I figured that it wasn't needed to understand how it actually works. If you have some time, look into it, the maths is fascinating and pretty straight forward. I'm Onno VK6FLAB

Checking your On-Air signal...

Mar 12, 2017 275


Foundations of Amateur Radio The other day I managed to achieve a little personal milestone. I heard myself on-air. Before you get all misty-eyed, yes, I've heard myself on-air before - probably on thousands of occasions over the years, but that's not what this was. This was my own transmitter, in my shack, transmitting my voice via SSB and it being received and me hearing it. In broadcast radio this is a common thing. Every radio station I've ever been in pipes the audio from a normal radio receiver into the studio, so you can confirm that your transmission is in fact going to air as expected. There are funny stories associated with experts who decided that they didn't need to wear headphones and promptly broadcast silence because their microphone volume was turned down or not plugged in - gotta love the helpful announcer in the previous shift. So, what was so special about hearing myself this time? Well, for the first time I heard my SSB voice. Not AM, not FM, SSB. I'd tried this before using two radios and a dummy load, but that just ended up in distortion, not much fun. Let me tell you how I managed this and what I learned along the way. Online I found a local Software Defined Radio, or SDR, that had the ability to tune to a frequency that I am allowed to transmit on. That seems pretty straightforward, but in actual fact getting those three things, Online, Local and Frequency all together has proven to be a bit of a challenge. I started listening to the station to see how their signal compared to mine. I have a project sitting on my shelf to put together my own SDR, but that ran into some procurement issues, so I've been limited in my ability to experiment. I started out trying to listen to the local HF beacon, part of the Northern California DX Beacon network. Turns out that the SDR and I can hear that pretty equally. I did notice that there was about a five second delay between what I heard off-air and what the SDR sent to me across the Internet. I don't know if the delay is because the Internet signal travelled back and forth across the country a couple of times, or because this particular SDR has some delays. I tuned the SDR to 28.490 and my radio to 28.490 and after checking if the frequency was in-use started some test transmissions. Nothing was working. No noise, nada. It does help if you plug the right antenna into the radio. Tada, look Ma, it makes noise! I could hear myself. It became clear that there was a difference in what I was expecting to hear and what I actually heard. Playing with different modes didn't seem to make any real difference, so I was a little stumped. I recalled that during a contest I had been advised that I was off frequency, so I played with my Tuning Dial, known as the VFO, and adjusted my frequency to 28.489.50 and there I was, just like I expected. Five second delay and all. At that point I wondered if this meant that the SDR frequency was wrong, or mine, or both - how could I prove it? Some hunting around for suggestions revealed the idea of tuning the SDR to one of the time frequencies, on 5, 10, 15, 20 and 25 MHz, better known as WWV and WWH. On these frequencies a 24 hour a day transmission happens that encodes the time. You'll hear a ticking clock, voice indicating time and it has all manner of extra information encoded in the signal. It's used as a time standard but also as a frequency reference. Best results are when you use AM and you can use it to get a sense of propagation between you and Colorado in the United States. Mind you they are using a few extra Watts. Zooming right in I could see that the SDR was indicating that it was bang on frequency, so I'm about 50 Hz off, high as it happens. Which just means that I need to tune a little lower than the frequency I want to be on and I'm good to go. Only I'm not yet convinced. I came across settings on my radio, the TX Carrier Point for USB, menu 18 on my Yaesu FT-857d. Other than various wild guesses by others, I...

If they're shooting at you - you know you're doing something right!

Mar 5, 2017 304


Foundations of Amateur Radio There's a quote from a television show that speaks greatly to me. "If they're shooting at you - you know you're doing something right!" I've been producing this weekly recording since May of 2011. It started life as "What use is an F-call?" and the first episode was recorded in response to an Amateur who bemoaned their transmitter power restrictions associated with their beginners license - when I used the same power to speak to a station 15,000km away the week before. I named the segment after the common term for my license - a Foundation License - in Australia known as an F-call. It's the so-called beginner's license, something you can get by spending a weekend with a book and passing a test that introduces you to the hobby of Amateur Radio. Since that first recording I've produced 296 different episodes, it was renamed to "Foundations of Amateur Radio" and I started putting the recording online as a podcast. In those episodes I've covered many different topics, from what to spend your money on, how to get started, what antenna's do and how you can build them, how different technologies work and what the Amateur Radio community is like. A recurring theme in my recordings is the attitude of other Amateurs to those who are starting in the hobby. I come back to it regularly because I keep getting emails from listeners who are subjected to varying levels of abuse by other Amateurs. I've taken to going to the Amateur Training College to explain that Amateurs are a mixed lot, many wonderful people and some rotten apples who make a lot of noise. I have had messages detailing abhorrent behaviour and read messages of those who left the hobby because of it. Fortunately the opposite is also true. I have messages from people who came back to this amazing adventure and got inspired by some of the things I've said and used this to rekindle their interest, or to finally go for their license, or to finally pluck up the courage and press the Push To Talk button on their radio and speak. We all make mistakes. I know I do. Sometimes I even find out that I made a mistake. For example, last week an Amateur told me that I'd claimed to have had 45 years of Computing Experience, which would make me a toddler when I started. Turns out he's right, I did claim that. Whoops. I meant to say 35 years, but wait for a bit and 45 years will be close enough. It's a shame that he didn't comment on the actual content of the segment, namely that we have a pre-conceived idea of what constitutes an Amateur, even though that is a changing thing. The episode is called "We should stop requiring electronics to be amateurs.", episode 28 of Foundations of Amateur Radio if you're interested. It's also a shame that he didn't point out a much larger error, in my episodes about chickens, but another Amateur, who sat on this for some time because he wasn't sure, caught up with me for lunch and we discussed in great detail what our common understanding was. We're still working out how exactly I explain what I said and how it differs from reality, suffice to say, I'm a curious kind-of-guy and I like to learn. That learning is also a regular topic of attack. It seems that some Amateurs who in the words of a wise-man - "who's only achievement in life was to pass their Amateur License" use my continued status as holder of a Foundation License as evidence that I'm clearly not able to pass my exam and ridicule my excuse of a License to claim that I want to talk to the world using 5 Watts before changing license. I've said it before and I'll say it again. This is your hobby. If you gain pleasure from getting a higher level of responsibility, then by all means do so. If you need something that your current license doesn't have, go for it. For me, my license does exactly what I want today, nothing more, nothing less. I have enough privileges to achieve what I want from this hobby today and my lowly license did not prevent me from spending...

The spirit of our hobby ...

Feb 26, 2017 292


Foundations of Amateur Radio Over the past six years or so I've single mindedly been producing a weekly segment about Amateur Radio. Over time this has evolved into a podcast which gets about half a million hits a year. Naturally I receive emails and I do my best to respond in a timely fashion. One of the other things I do is announce a new edition of the podcast on several different sites where listeners have the opportunity to share their views about what ever is on their mind. Sometimes their response is even about the podcast itself, though I confess that some comments appear to indicate that listening isn't part of a requirement to actually form an opinion about what it is that I have said that week. All that aside, I find it immensely fascinating that the responses I receive vary so much in perspective. It's not hard to understand and observe that our community comes from people along all walks of life. From nine-year olds to ninety-year olds and everything in between. I tend not to comment directly on such feedback, since everyone has their own opinion, but I came across one post recently that made me sad about the spirit of some Amateurs. In a seemingly bygone era there was a sense that Amateurs would help new people join the community and help them find their way into this vast range of discovery. A place where no question was wrong, where shared experiences are cherished and where the lack of knowledge was an opportunity for learning. It seems that the moniker that we carry, that of HAM, supposedly because when compared to Professional Telegraphers, we were considered HAM-fisted, went on to form the basis of a proud tradition of experimentation and renewal. Across the globe we see a refresh of the license conditions on a regular basis. We saw that here in Australia with the introduction of the so-called Z-call and K-call, looked down upon by Real Amateurs who had a much more stringent licensing regime. We discontinued Morse Code as a requirement for an Amateur License as part of a global treaty agreement in 2003. In Australia this meant that from the 1st of January 2004, Morse Code was no longer required if you wanted to obtain an Amateur License. As you know, that didn't signal the end of Morse, just that it wasn't legally required any more. I'm one of many Amateurs learning Morse because I want to, not because I have to. I'd also point out that it was discontinued by global agreement, not two random guys in Canberra. Back to my point about the spirit of this hobby. The point that was being made is that the Foundation Class license isn't a real license and that it is just being handed to anyone who asks, not like their requirements for Morse Code and a written exam, rather than a multiple-choice test. Essentially conveying that my undignified license and that of my fellow Foundation Licensees isn't to be confused with the noble one that a Real Amateur holds. This kind of response saddens me and frankly I hear it too often. It's as-if we as a community still have not learned that the world moves on. Technology, in many ways the basis of Amateur Radio, evolves. For example, in the current requirements for an Amateur License there is a long-winded discussion about the impacts of spurious transmissions on Analogue Television. In Australia, the last Analogue TV broadcast happened on the 4th of December 2013, that's years ago, but it's still required reading on the Amateur License Syllabus. Similarly we learn about Valves, but attempting to actually obtain such a device is nigh-on impossible. Should we still be learning about those aspects of Electronics, or should we move on? Amateurs are an inventive lot, we make up new modes, link up new technologies, experiment with all manner of stuff and sometimes we end up with something new, like IRLP, AllStar, SDR, Digital Modes and the like. All because someone got curious, couldn't help themselves and started to fiddle. As things fall off the radar at one end,...

This hobby is dead ... NOT!

Feb 19, 2017 274


Foundations of Amateur Radio Recently I was told that Amateur Radio as a hobby is dead. This isn't news. It's often repeated and the story goes like this. The hobby is full of old dying men who when they finally shuffle off this mortal coil, or as we like to say "become a silent key", will take their hobby with them. There is anecdotal evidence to back this up. An organisation that tasked itself with the preservation of Morse Code in the tradition of Telegraphers and Seafarers is forecasting their demise due to the age of their membership. Other comments along these same lines talk about the futility of Amateur Radio in the face of other communication tools such as the Internet, Mobile Phones and the like. Emergency Services often ignore the Amateur Radio Service because they have all the communication infrastructure they need. People point at the declining numbers of Amateurs and say: "See, I told you, the numbers don't lie!" If you listen to this you might wonder why it is that you're fascinated by this endeavour and what it is that these tales of doom and gloom for the future of our hobby mean for you. Let's start with the numbers. In Australia in 2005 a new class of Amateur License was introduced. It's called the Foundation License and the purpose was to attract new people into the hobby of Amateur Radio. Looking at the numbers we see a year on year increase in the number of Foundation Calls. Many of those go on to gain extra responsibilities by getting a Standard or Advanced License. Some Amateurs let their Foundation Call lapse, so the increase of people entering is actually higher than a simple count of callsigns might suggest. So, we're getting more and more people into the hobby every year. But the overall numbers are declining. How can that be? Well, simple really. We don't have a problem with growth, we have a problem with retention. This means that as a community we're doing great things about getting new people into our wonderful hobby but doing a poor job at making them feel welcome and keep coming back. Those are numbers, but there are other things happening as well. The Internet today is a connection, actually an Inter-connection of networks. You might be surprised to learn that these networks started when we figured out how to use Morse Code on wires to send messages across the globe. While the original copper is probably not being used, though that in itself would be an interesting research project, the Internet today has its roots in the Morse Code driven Telegraphy network. The very first one of those was set up over 200 years ago in 1816. There is a long history of explaining the relationship between wire Telegraph and Radio Communication, featuring long cats, dogs and a war between Austria and Prussia. Suffice to say that Telegraphy and Radio Communications both form part of a symbiotic relationship. It still does today. The Wired Internet and the Wireless Internet are the same animal dressed up with fancy technology. Amateur Radio is the experimental arm of Radio Communications, so as long as humans want to communicate with each other we're here to stay. Time and again, Emergency Services need operators in the case of an actual emergency and historically they have been drawn from wherever experienced bodies could be rousted, suffice to say, the Amateur community keeps on giving. As for the old and dying men. Sure, we have some amazing history that senior members of the Amateur community have to contribute, with many lessons to be learned for the likes of young'ns like me, but I'm getting older every day and with me the rest of the population too. At some point we'll all be older and wiser, perhaps we'll even be Amateurs. Another way of looking at this is as the global population gets older with more free time on their hands, the more opportunities exist to introduce people into our hobby. As for the retention. As a community we really need to investigate what it is that makes people...

Sun-Spots and Amateur Radio

Feb 12, 2017 323


Foundations of Amateur Radio Amateur Radio as a hobby is one of those activities that covers a wide range of pursuits. A fellow Amateur once referred to it at 1000 hobbies in one. I like that as a description, but it really doesn't cover how wide and extensive this hobby really is. You've heard me talk about radios and on-air activity, about contesting, about out door activities, about electronics and antennas, about the grey line and about decibels. Today I'm going to talk about the Sun. Using a hand-held radio you're often using higher frequencies, 2m, or 144 MHz or higher. These radio waves mostly travel along line-of-sight. If you look at the lower frequencies, called HF, 28 MHz, 21 MHz, or lower, then those radio waves also travel line-of-sight, but they also travel up into the ionosphere surrounding the earth. If you manage to hit the angle just right, then some of those will reflect off the ionosphere back to earth. It's a lot like skipping a stone on a pond. If you get it right, you might make it skip several bounces, if you get it wrong, it will go "plop" and vanish. The same is true for these frequencies. One of the things that makes the ionosphere reflective to radio waves of a certain frequency is the level of ionisation in this area around the globe. Typically the ionosphere is somewhere between 50km and 1000km above you right now. At different heights the ionosphere reacts differently and the Sun shining on it will alter the properties as the day unfolds. This is why when night turns into day and day turns into night, special things start happening along the border between day and night, the so-called grey line where it's not quite day and it's not quite night. One way of looking at this is that the ionosphere heats up during the day. Now heat is an interesting thing. The Sun shining on your skin is experienced as heat, but what's actually happening is that the radiation from the Sun is exciting the electrons on your skin and you experience that as heat. As a matter of interest, the Sun generates about 650 Watts per square meter in the middle of the day coming through the atmosphere. That's about 650 Joules of Energy per second per square meter. Lots of excitement. At the outside of the earth, there's about 1300 Watts per square meter. The difference, 650 Watts, is absorbed by the atmosphere. So, the equivalent of the heat you feel on your skin is also heating up the atmosphere. Now, this "heat" is really energy that's exciting electrons and thus also exciting the ionosphere. At the simplest level this is making the ionosphere more reflective to radio waves. I'm deliberately simplifying this because I don't want to get bogged down into how precisely, because my point is about the Sun and more specifically about Sun-spots. There I said it, Sun-spots. What are they and what do they have to do with anything? Well, a Sun-spot is a cool place on the Sun. When I say cool, it's about half as warm at a Sun-spot than the area around it, only 3000 degrees Celsius, instead of 6000 degrees. Sun-spots appear in pairs on opposite sides of the Sun and represent a point on the Sun where an intense magnetic field comes through the Sun. You can think of it as a huge race-track through the Sun that accelerates particles from the Sun into space. These particles represent energy and if they happen to hit the earth, they add a whole lot of extra energy to the ionosphere, making it much more reflective. The more Sun-spots, the more energy, the more excitement of the ionosphere, the more reflection, the better radio communications. Sun-spots generally appear in groups and the density of these groups varies over time. To get a uniform sense of how much energy there is around, scientists came up with a Sun-spot number. It's indicative of how much activity there is, not an actual count of the number of dots on the Sun, since some spots are large and others are relatively small. The increase and decrease of solar activity...

What does MARS have to do with Amateur Radio?

Feb 5, 2017 451


Foundations of Amateur Radio In my travels along the highways and byways of the Internet I came across several references to MARS in relation to Amateur Radio. Being the curious soul that I am, my interest was sparked. I must warn you, today there is a lot to cover. First up before I tell you anything, let me start by pointing out that what I'm talking about has different levels of application depending on where you are on the planet. I also need to inform you that in some parts of the globe this is considered illegal, where in other parts of the same globe, it's perfectly fine. So, MARS, or MARS/CAP if you want to get more precise. What is it, how does it work and what do you need to know about it? MARS is an acronym for Military Auxiliary Radio System and CAP is an acronym for Civil Air Patrol. Given that we don't have such things in Australia, this phenomenon relates to the United States of America where MARS/CAP is used to coordinate search activities and relay messages on HF and VHF frequencies near Amateur Bands. As an interested party you can join up, do training and participate. That aside, the term MARS/CAP is more widely referred to as a way of modifying your radio to allow it to access to frequencies outside the Amateur Bands. Now at this point if you're a licensed Amateur your ears should have pricked up when you heard the words "modifying your radio" and "outside the Amateur Bands". This is as I already said, legal in some parts of the globe and not in other parts. So, a MARS/CAP modification extends the frequency coverage of your radio. Some modifications involve extending what frequencies you can receive, others extend the transmit frequencies. Often these changes are separate, but not always, so make yourself aware of what you're doing before you do anything. Now why am I telling you about something that some might consider shady or illegal? First of all, I've not actually told you what to do or how to do it. Second, if you're trawling through the Internet and you come across such a thing, how would you know what it means in your situation, other than a list of instructions shown on some random website? There are several different aspects to this. As I mentioned, the legal aspect which I'll discuss a little more later. There's also the technical, performance and warranty aspects to consider. Not to mention, emergencies and other exceptions. From a technical perspective, there are generally two types of MARS/CAP modifications. There are hardware ones where you pull out your soldering iron and modify the circuit on your radio by adding or removing something. There are also software modifications where updating the version of the software on your radio, or changing a flag, or setting a memory will make the modification. The hardware changes are generally pretty permanent, the software ones are often able to be reverted back to normal, but not always. While I'm warning you, some radios when opened up reset their memories, so you may need to reprogram all those channels when you put it back together again. Now, your Amateur Radio is a finely tuned animal. It's specifically configured to work within the specifications of the Amateur Bands and regulations and as you should know, there isn't a single piece of hardware that exists that isn't subject to the variation of its components. This means that if you compare two identical radios, the same batch, the same builder, they still are not identical. If you put them on a testing bench, you'll notice subtle differences. They'll be close, but not the same. Each one is specifically set with preferences, variable capacitors, inductors and resistors to respond just so, and meddling with the hardware or software can - and likely will - change this finely balanced piece of gear. If you're fiddling to fiddle, be aware that you might never get your radio back to the way it was before you changed it. If you let the magic black smoke out of your radio and return it...

A nifty idea looking for a purpose in 1947 changes the world as we know it...

Jan 29, 2017 309


Foundations of Amateur Radio If you have the need to switch something on and off, a likely first candidate is to get a switch from the local hardware store. The principle is pretty straightforward. You put the switch into the power supply lead and by pushing it on, the two halves of the switch make contact with each other, completing a circuit, and the thing you're switching turns on. It's a lot like having two bits of bare wire that you can touch the ends together. What if you want to remove the human touch from the equation, that is, switch something without having to actually push a switch? A potential candidate for this is a relay. In essence it's exactly the same as a manual switch, except the pushing is done by an electromagnet. The way it works is that you send a current through a coil that is wound around a metal core which results in a magnetic force. This force is used to push or pull the switch open or closed. Now both a manual switch and a relay have moving parts. That means that there is a limit to how fast you can switch something on and off. You can probably push a manual switch several times a second, lets say 10. So the switching speed is called 10 Hz. A relay can likely get you switching around 100 times per second, or 100 Hz, but if you want to switch something at a much higher speed, say at 1000 Hz or more, some other form of switching comes into play. At its simplest, a transistor is like a relay without any moving parts. There's no actual switch, no coil, no electromagnet, none of that. Without going into the physics of how this all works, let's look at an analogy. Imagine a water-pipe with a valve on it. You can open or close the valve and water flows or not. In a transistor, the same principle applies. There are three legs, two of them act as the water pipe, the third one acts as the valve. You open or close the valve by putting a current onto the valve - or base - leg and a current flows between the other two, the collector leg and emitter leg. Now, so far I've just told you that you can open or close a transistor with a current, but it's actually more nifty than that. You don't need to have it all on or all off. In our water pipe you can set the valve to any setting and control how much water flows. In a transistor you can do the same by changing how much current you put onto the switching or base leg. You might have heard a description that says that a transistor is both a switch and an amplifier. If you haven't don't fret, I'll explain. Let's go back to water for a moment. Imagine a huge water pipe connected to a dam. Lots of water all pushing into our water pipe. The valve we have can be controlled by you blowing water through a straw into the valve. The more water you blow into the valve, the more water flows out of the dam through the pipe. If you blow hard into the straw, the result is a wide open valve and lots of water from the dam, if you blow softly, less water. In essence your little water flow from your straw is being amplified by the dam. A transistor works just like that. As I said, you don't have to use a transistor just to switch something completely on, or completely off. If you vary the current into the base, you can vary the amount of flow between the collector leg and emitter leg. The current you use to control the flow is tiny, so you can use a really weak signal to control the thing. In essence that's how a transistor radio works. The small signal that we use to control the flow is the tiny one coming from an antenna, the dam is the battery and the speaker is connected to the output. So, a small electrical current coming from the antenna controls the transistor which in turn controls the amount of current coming from the battery onto the speaker. A hearing aid also works in the same way. A small current coming from a microphone controls the transistor which in turn controls the amount of output from the battery to a speaker. The reason I mention transistor radios...

Beauty is in the eye of the beholder ...

Jan 22, 2017 357


Foundations of Amateur Radio Beauty is in the eye of the beholder. I look at an antenna and marvel at what it implies. A simple piece of conducting material made into some particular shape and size that harnesses the radio spectrum. I find it fascinating that this can and does exist and my fascination translates into a thing of beauty. I recall being on a camping trip and being introduced by a friend to an antenna that was strung between two trees in the middle of the bush. For some reason that escapes me we needed to lower the antenna and I got to have a look at the feed-point. Let me describe this to you. Picture a ceramic fence insulator. The two legs of the wire dipole are each fed through the insulator at a 90 degree offset, in just the same way as you would install it into an electric fence. Looped around this is a piece of RG213 coax which is soldered onto each leg of the dipole, shield to one side, centre to the other. No traditional balun, but there is a piece of wire wrapped around the coax, holding it all together and I have no doubt that it acts as some form of choke. This thing looks absolutely horrible. It's weathered, it's rough, it's nasty, has spider-webs and other little critters living in the insulator, the soldering is quick and dirty, the shield is roughly attached to one of the legs. If you've been in the Australian Bush and visited a farm there you'll know exactly how rough and ready this antenna is. I seem to recall that its proud owner (Hi Kim) put it up temporarily in a hurry to get on air one day, a decade or so ago. So, what of this ugly mess? It was the best antenna I've used in a long while. It allowed me to make my first QRP contact across the length of Australia into New Zealand. It allowed me to contact the 7130 DX net for the first time and we talked to a globe circumnavigating sailor on this antenna. So, as ugly as this thing is to look at, from an antenna perspective, it's the most beautiful thing I've seen in a while. Now, you need to know something. I saw this antenna nearly four years ago. I have photos of it. Every now and then I go back to those photos and marvel at it. In our hobby we have people from all different walks of life. It's been pointed out on more than one occasion that as a community, the single piece of glue we have is our Amateur License. Of course some of us have more in common than just that, but it would be smart to remember that every member of our community has a different view on aesthetics, a different perspective on what is good and what is bad. I recall coming into a new radio club, I had been an Amateur for less than a month, and bringing along my shiny new Yaesu FT-857d, I was so proud of my acquisition. It was everything I liked in a radio. I'd bought it with hard-earned cash and I was chuffed to show it off. One of the first comments I received was: "Well that's an ugly radio!". Suffice to say that I was unimpressed with that assertion. Their perspective was based on their love of the FT-897, which has a different shape, one that didn't particularly appeal to me. Since that experience I've attempted to subject myself to many different radios. It's become apparent to me that everyone has a different thing they like about their radio. For one it's the layout, for the other the filters, another likes the colour, the price, the number of buttons, the history, its power consumption, the brand, the whatever. Each to their own. I'm pretty sure that I'm also biased. I recall at least two instances where friends of mine purchased a radio that I would not have considered since they lacked a particular feature that I felt was essential. I'm not sure I was gracious in my assessment of their new purchase, but I hope to make amends. In some workplaces there are policies of tolerance in place. There is an assumption that people are going to be together in the same place for long stretches of time with different cultures, different outlooks, needs and...

More strange antennas!

Jan 15, 2017 233


Foundations of Amateur Radio About ten minutes ago I was blissfully unaware of the existence of James K2MIJ. It's unclear if this bliss will ever be returned because it's obvious to me that James and I share several things, a sense of humour among them. Mind you, I've not yet actually spoken to James, other than me saying "Hello" right now, but his QRZ page is a thing of wonder. Last week I was talking about weird and wonderful antennas. As you know, Amateur Radios don't particularly care what you plug into the back, as long as it looks like a 50 Ohm load, the vast majority of transceivers will happily transmit into them. I've heard of people making contacts with dummy loads, bits of wet string, chairs and as I said last week, bridges and rail-road tracks. James has made it his mission to tune up strange things. He's made a lawn chair dipole and is using it to contact all states across the US, with only 5 Watts. He's added more countries to his DXCC than I have - 53 - and while he's at it, he also made some other contraptions, a fork dipole, from two actual kitchen forks, his in-the-shack dipole and his latest contraptions, a collection of five and a half inch and nine inch antennas. You heard that right, a five and a half inch antenna for 40 meters. If you go to James' QRZ page, you'll find a kitchen table, holding an antenna farm that rivals those of many stations. Antennas for 40, 30, 20 and 17 meters. One thing that piqued my curiosity is a photo of his 20m antenna sitting on the ground. Picture something like a peanut butter jar lid with a piece of copper stuck in the middle, standing up. It's wound around in a spiral with two windings, sort of like a big loading coil you'd find on a 2m vertical antenna. The base of the contraption has about 30 or so windings on it which you connect between the copper and the feed-line. The thing that got my interest was what was on the other side of the feed-line, a tape measure. More precisely, a steel tape measure. As I said, I've not yet spoken to James, but it might be that his mini-antenna is mostly made of tape measure. Don't get me wrong, I think experimentation is wonderful and he's clearly made more contacts that I have, but I'd love to learn what effect the tape measure has on his contraptions. I noticed a few other things that people have tuned up, beer cans, especially helpful with Fox Hunting, when one of your friends, or should I say Fiends, sets up a secret transmitter that you and several teams have to track down. The more devious the antenna installation, the better. There's the quintessential flag-pole antenna for those times that your neighbours need to see that you're patriotic and not a nasty radio amateur with unsightly antennas that reduce the value of their home and remove the enjoyment of their life because your hobby affects their ability to sleep at night. I've seen people tune up their gutters, even tried it myself - the noise floor in my shack prevents anything sensible, but I'm working on it - and of course there's the proverbial boat on a trailer antenna. No interest in sailing as such, just a nice tall aluminium construction that could perhaps be connected via some feed-line to a nearby radio transmitter. It's not even a permanent structure, so it'll add value to the neighbourhood. Making a weird and wonderful antenna as an experiment is great for learning, it's great for experimentation and dealing with emergencies and it might keep your neighbourhood happy too - mind you, why anyone would think that an antenna is ugly is beyond me. I'm Onno VK6FLAB

Tuning up strange antennas ...

Jan 8, 2017 189


Foundations of Amateur Radio During the week I received a funny picture from a fellow amateur. This particular image was one titled "Multitap Antenna" and it featured a Four Wheel Drive vehicle with a bull-bar and a spring base mounted antenna. The antenna was made from pipe and at suitable intervals the pipe had a t-piece with a tap. Nothing too peculiar, right? Well, other than that the taps were standard brass garden taps with a hose-quick release clip and hose fittings. Made me laugh. Anyway, that reminded me of a series of postings on Social Media about the random things people have used as antennas, from emergency bits of copper wire attached to flag-poles to get a local station back on the air during an emergency to tuning up wire fences, bed frames and the like. There's even a "Strange Antenna Challenge" with suggestions of ladders, baby chairs - presumably without the baby, umbrellas in trees and other fun stuff. Suggestions to contact your local TV station to promote the activity to bring back some fun into Amateur Radio. Now, why am I even talking about this? As Amateurs we take ourselves very seriously, so seriously that any idea that isn't following the norm is scoffed at. "This is how we do things around here" and "That will never work" are often heard in group discussions among the knowing elite of Amateur Radio. Here's the thing. We're Amateurs, experimenters, licensed to test, to play, to learn. What if you find yourself on the side of the road with an up-side-down vehicle with a perfectly working radio, but a broken off antenna? What would you do? What if a storm blew your antenna down, or it was destroyed by a flood? How would you cope? Would you bring out your trusty spare antenna and plug that in, or would it be helpful to have some experience with tuning up weird stuff and seeing what happens? For my money, I'd rather know an Amateur who can make the proverbial wet piece of string work, than the one who has the latest gadgets and gizmo's ready for that day that the emergency arrives. Hopefully their spare antenna will be in their car and not sitting in the Garage waiting for the emergency to arrive at the right time and place. So, if you did in fact have some fun and started playing, some of this is going to fail and some of it will work poorly and some of it won't work at all and you might damage your radio if you pump full power into a random piece of conductive material, but, you might also just come across some skills that you could use when it becomes essential, or when you're up a creek without a paddle. So, when you've done everything and are looking for the next challenge, have a look at the Strange Antenna Challenge, there's been activity going back over a decade featuring two cars as antennas, rail road tracks, a bronze statue, exercise machines, a football stadium and a bridge. The only requirements are that no wire and no metal pipe allowed. Remember to take a photo of your contraption, so you can share your adventure. I'm Onno VK6FLAB

Do we really understand our hobby?

Jan 1, 2017 177


Foundations of Amateur Radio Today I was going to talk to you about Grid Dip Oscillators. Some research later I realised that I don't yet understand the topic enough to explain it to myself, let alone explain it to you. I then set my sights on a simpler thing, an SWR Meter. Pretty standard fare in a radio shack. You plug it in and off you go, nothing to it. So I then set about learning how this actually works. As you know, if it's written on the Internet, it must be true, and in this case, there must be a thousand different explanations and ways that this common black box works in your shack. Since I found so many different explanations that made me recall a quote: "You do not really understand something unless you can explain it to your grandmother." So, at this point I should sit down and explain it to you as if you're my grandmother, right? Unfortunately I'm not yet at that level of understanding, so I'll not add to the noise of explanation until such time as I do understand it. Instead I'm going to take a left turn and observe that Amateur Radio is full of explanations. Some of them great, many of them horrendous. I see Amateurs on-line arguing about how something works and then I hear them on-air doing more of the same. It occurs to me that where ever there is argument about how something works there is one of two things going on, lack of knowledge or lack of understanding. I'm not saying that every Amateur doesn't understand, I'm wondering if it's possible that our collective understanding of how our hobby works appears to be lacking in scientific rigour and that it's incomplete. I'm wondering how much of our hobby is actually understood and documented. While I'm here, I should point out that taking observations of a phenomenon isn't an explanation of how it works. The observations will get you places, but the unexpected or unobserved might get you killed along the way. I've said in the past that this hobby is like Magic and I still think that. The more I learn and understand about it, the more Magic comes in to play. This is what keeps drawing me back to this wonderful world of Amateur Radio. While I was searching for my SWR explanation I came across this little gem which speaks to me greatly and goes a long way to explaining why some of our hobby is so misunderstood: "the reason that your friends and ours cannot understand mathematics is not because they have no head for figures, but because they are unable to achieve the degree of concentration required to follow a moderately involved sequence of inferences" So, next time you sit down to explain how something works, bear that in mind, since following along a string of things that lead to an explanation might not be something your, or my, friends are willing to put up with. I wish I'd seen that quote before I attempted to explain why I had several antennas on the roof and couldn't just have one. Still learning... I'm Onno VK6FLAB

SOTA goat adventures ...

Dec 25, 2016 429


Foundations of Amateur Radio Last week I went on an adventure and came home with an experience. I've been wanting to go out and play radio for a while. Work has been spectacularly unhelpful in making time available to achieve this, not to mention the 17 million other things vying for my undivided attention. Last week the planets aligned and my outing came to pass. I'd set my sights on doing a SOTA activation. If you're not familiar with that, SOTA is an acronym for Summits On The Air and the aim is to get to the top of a mountain and make contacts from there. I've previously been under the tutelage and presence of some very experienced SOTA hams and during a conference in Canberra last year I managed to activate several summits with others. I even managed to survive walking up one peak on my own, using my hand-held to make some contacts. I use the word survive in less than ironic terms because I relied on Google Maps to navigate me up to the peak and for reasons best known to Google, it walked me up the side of the peak that didn't actually have a track, even though the map was adamant that I should follow the path. Many, many hours later, not properly dressed, not enough food, weather coming in, batteries running low, I managed to get back down safely and hobbled to a taxi who brought me back to my hotel. It was memorable, but not for the right reasons and it didn't involve HF communications and at the moment I'm struggling to recall if I actually logged those contacts. That will be a job for another day. Anyway, as I said, the planets aligned and I had a day to myself, access to the car, a charged radio battery pack, a working antenna and a map that worked. Mind you, I spent an hour fighting technology. First to register on the SOTA web-site, then to activate the software on my phone, then to get Google Maps to actually navigate me to the peak and for it to download the off-line maps, so I could navigate whilst out of mobile phone range. Lesson learned, plan to do the technology before the day. So, I set off an hour later than planned, but I was finally on my way. Google Maps again let me down by navigating a different route than I wanted, since I had the choice of more or less dirt road and I wanted less. Google picked the other one, even though I pointed it at the one I wanted. Another lesson learned, make sure that you add markers to your route before Google Maps starts you on your way, since there is no changing it once you're driving. After an hour and a bit I arrived at the top of the peak. If you're interested, it was Mount Dale, or SOTA peak VK6/SW-036, but before you go looking for my log, stick around, there's more to the story. So, I set-up my antenna, a multi-tap Outbacker and set it to 40m. I appeared to have mobile phone coverage, so I added my spot to the SOTA-watch website and started calling CQ. I managed my first contact within 8 minutes of my advertised time start time, so I was pretty chuffed. For the next few hours on 40m and 15m I managed contacts with 23 stations. The biggest distance I managed was 5353 km, or 1071 km per Watt. Not bad for a vertical antenna mounted to my car. I did some experiments along the way with turning my car around, getting better and worse signals, but overall it was great. I had a little play with 2m, but didn't manage anything other than talking on the local repeater, which is located 24 kilometres away and about 250 meters lower down. One friend suggested that there was a satellite pass coming over later in the day, but by the time I'd been there for four hours I was cooked. It wasn't spectacularly hot or anything, but it was time to go. No satellite this time, but something to add to my list of things to check. I came home and basked in the enjoyment of having gone out and made contacts, more than I'd managed for most of the year. Very satisfied. The next morning I found an email from the SOTA manager in VK6 who asked me about my operating environment. After...

Passion and Politics

Dec 18, 2016 183


Foundations of Amateur Radio Today I want to talk about Politics. I can hear you groan from here, so hold your horses, stow your tar and feathers and put your pitchfork back in the barn. Amateur Radio is a hobby. It's to do with electronics and physics and the ionosphere and other cool stuff. Some people call Amateur Radio a thousand hobbies in one and that's a pretty good description. Underlying Amateur Radio are the people. Those who have spent their time studying, learning new skills, doing tests, passing exams, as well as people who are interested bystanders, not necessarily licensed, but drawn towards the bounty that Amateur Radio as a hobby represents. An interesting phenomenon among people is their varying level of passion. Some people are passionate about their dog, others about their children, others are passionate about cars, or baking, or in our case, passionate about Amateur Radio. Passion has been explained to me once as a "big elephant". You sit on its back and it takes you where you want to go. Gentle nudging makes the elephant change direction, but if it gets excitable or startled, it'll go where ever it wants and all you can do is be a passenger and hold on tight. If you mix passion and Amateur Radio, there are times when that will result in heated discussion about the merits or pitfalls of a particular radio, an antenna or some other aspect of the hobby. If you group people together into radio clubs then those clubs are made of passionate individuals who come together to promote the objects of their club. As people group and discuss, opinions differ, goals morph and change and aims and objectives are blurred. Before long, you get special interest groups, proponents and opponents, elections, board meetings, stoushes, mis-management, legal action and the whole gamut of life. To complicate matters, Amateur Radio uses a public resource, radio spectrum. This is generally managed and maintained by a regulator, which in turn is generally managed by, politicians. What this means is that as a Radio Amateur you should not be surprised to learn that politics plays a part just as it does in the rest of society. I can still hear you muttering from here. My In-Box hasn't yet seen any derisive emails, but I can picture their arrival. What does this all mean? It means that Amateur Radio is not one thing. It never has been and never will be. For each individual there is a personal path to find and a journey to travel. For some this means that they'll become the Contester of the Year, for others it means that they'll invent a new gadget, others will use Amateur Radio as an excuse to travel the globe and others will use it to be the big cheese in their club. Your role is simple. Remember that this is a Hobby. That it's your hobby and that you have as much say in it as the next person. Remember also that this Hobby exists because we've been given access to a public resource and it's our responsibility as Amateurs to conduct ourselves in a manner that befits that public trust. I'm Onno VK6FLAB

Coax vertical dipole and other musings ...

Dec 11, 2016 293


Foundations of Amateur Radio The other day I celebrated my sixth birthday, no not that one, the one that reminds me when I first became licensed as a Radio Amateur. It caused me to reflect on what I've done with my license and what I've learned and where I'm heading. A recurring theme in my Amateur life is one of upgrading. Not a month goes by when someone makes a comment about my license status. As you might know, I hold the entry level license in Australia, the Foundation License as it's called. Other countries call theirs different things, but the aim of this license type is to introduce new entrants into the hobby and for me it's done that in spades. If you've listened to some of my previous mutterings and musings, or if you've listened to all of them, heading for 300 now, you'll have noticed that it's rare that I'm not talking about something I learned, something new, or something that interests me that I've found and I want to share with the community. This quest for knowledge, learning and curiosity is something that I've always had and I'm sure I'm not alone with those traits. It occurred to me that my newly minted Amateur License achieved exactly what it intended to, Introduce me to Amateur Radio. It did more than that. It set me on a path that I'm travelling down today where I'm learning a new thing most weeks and telling others about it. I don't yet fully grasp the difference between an NPN and a PNP transistor, nor do I understand the workings of a Valve to the point where I can explain it to you, but the truth of the matter is that I haven't had the need to, or at this stage the curiosity to. That's not to say that a day will come when I do want to know. So here's the thing. Would you rather I have the highest level of license, having passed my test, cramming for my exam, guessing answers on a multiple-choice form, or would it be better if I came to know and understand the body of work that makes up the foundations of our hobby? As an aside, I have taken a mock test at some point. If I recall, I managed a score of 75% or so, might have been higher, but it outlined the areas of knowledge that I don't have at this time and that was why I took it in the first place. There are Amateurs who pass tests and then there are Amateurs who learn. One final comment about upgrading. When was the last time you upgraded your car license to the next level, say rally driver, or Formula-1 driver? When was the last time you got called out on not having upgraded and admonished for being a lowly car driver? Onto Amateur stuff. First of all, the wheel bearing has gone to a better place. It drove away on a big blue truck on Wednesday morning and is no longer. So sad. In antenna news, you may recall my experiences with the installation and tuning of an antenna for a friend of mine. I made all manner of what some would call outlandish statements, one Amateur all but called me a liar and accused me of making it all up to promote my podcast. All this excitement because I dared query the documentation of an Antenna. I've reached out to the manufacturer, but I've not yet received a response. I'm told that my hunch that this was a vertical dipole was correct. That in itself is curious since I've been experimenting with a vertical dipole made from coax, not enough to talk about success yet, but enough to be told that it will never work. Gotta love the doubters. As I suspected, the cut-off piece of inner coax, if you recall, the one that was a centimetre or so too long, is half of a capacitor, the other half is in the base of the antenna. Note that all this is based on what I've been told by a fellow amateur, and I'm looking forward to hearing from the manufacturer what they have to say. So, my vertical coax antenna idea started off with the idea that I wanted to use a vertical dipole for working portable. I realised that some of the designs I've seen knocking around the 'net are cutting off long chunks of shield, or folding it...

Manufacturer drivel and antennas ...

Dec 4, 2016 241


Foundations of Amateur Radio Let me start completely off-topic today with a thank you for emails and other expressions of concern regarding the demise of the bearing last week from my messy desk. I did not loose my marbles, other than the ball bearings in the disposed item and my sanity is as intact as it ever was. I was also asked for photos of the messy desk and as a concession to that I'll use a photo of the ball bearing for the podcast edition this week. How am I able to produce a photo of the disposed ball bearing? Truth be told, it's in the bin, the bin is in my office, but it wasn't emptied last week, since there was so little inside, so the ball bearing lives - until Tuesday when the bin will surely be emptied. Now, on to Amateur Radio matters, since that's why I'm here, though based on your emails, I'm not quite yet sure why you're here. Yesterday a good friend of mine, who tragically has yet to see the light and become a licensed Amateur came to me with a non-functioning antenna. He had purchased a so-called "Ground Independent Monopole" suitable for 380 to 520 MHz. You get no points for guessing that this was to be used for a CB installation on his vehicle. When you read the accompanying material, this magical antenna has a 4 dB improvement when compared to a 3 wave whip in the centre of a metal roof. But then when you look at the foot note, it talks about a 4 dB improvement over a 1/4 wave whip, but pattern tests only deliver a 2 to 2.5dB actual gain. I can hear you groaning from here. It leads me to several observations. As a licensed amateur you should be able to already spot holes as wide as a semi-trailer in those few statements. As amateurs we're often dismissive of the CB community, but how can they be held to account if manufacturers publish what looks to me like drivel of the highest order. The design itself is curious. There appears to be a loading coil in the base, the centre of the coax is trimmed to a specified length and inserted through the coil and electrical continuity exists between the radiating element and the coax shield. After spending some time trouble-shooting the installation I determined that the PL259 connector at the end wasn't actually soldered to the coax, so we fixed that. Using my antenna analyser we trimmed the vertical as specified, a couple of millimetres at a time, but it wasn't setting the world on fire with the updated SWR charts I was generating. We stopped trimming when we got close, since cutting off length is easy, cutting on length not so much. I then re-read the instructions and queried the length of the trimmed bit of inner coax that was inserted into the loading coil and found out that it was about a centimetre too long. Fingers crossed we trimmed that to length and the SWR chart improved. It still didn't set the world on fire, but at least the SWR wasn't 8 to 1 on CB Channel 40. Of course I've urged my friend to get an Amateur License, but that's ultimately their own choice. What I took away from the experience is that even a very basic Amateur License like the one I hold is sufficient to understand better what is going on and to be able to begin the process of trouble-shooting antenna installations. I thought I understood that this antenna was basically a vertical dipole, but at the moment I'm not sure and I'm wondering if the loading coil is actually a matching circuit and I wonder why the coax shield and the radiator are connected to each other. I'm sure the antenna is designed with the best intentions and I'm moderately confident that it works as intended. Now all we need to do is train the marketing department to talk to the engineering department before publishing their materials. For me the take-away is two fold. Don't blame a CB-er for their lack of knowledge, sometimes the manufacturer is to blame. The other take-away is that with a basic understanding of Amateur Radio you can help your fellow radio operator. Now, where on my desk is that...

Messy shacks are the way we do things around here.

Nov 27, 2016 273


Foundations of Amateur Radio In my time as a member of the radio community I've been in around 30 different shacks and a similar amount of camp-out style activations. I've operated at least a hundred different radio set-ups with different operating styles, logging systems and power sources. I wouldn't say that I was particularly experienced, but I've seen enough to make some observations. My first observation is that radio shacks and set-ups tend to be messy. It's not unusual to see several radios, antenna tuners, amplifiers, switches, computers, power supplies, soldering iron and accumulated cruft in the form of resistors, wires, spare antennas, connectors, screws, knobs and globs of solder, all vying for space on the same bench at the same time. I'm looking at my own desk right now and I can count a hundred different objects within 60 seconds with no effort what-so-ever, and that's on a desk that's barely larger than a square meter in size. I'm not particularly messy in the scheme of things. There's no food on this desk - other than the cup of coffee I've just made and there's no globs of solder or other sticky things like oil and glue, but still. One of my friends remarked the other day that no matter how much space we have, we always seem to run out. He wondered why. At the time, my reply was something along the lines of: "Well, it's for the same reason as your bank-account never has enough money in it." While that observation is probably valid, I'd like to point out some side effects of a messy desk. If your intent is to operate the radio and get on air to make noise, there needs to be a working station. You need to be able to test it without having to move stuff around and fault finding needs to be part of the way the thing is set-up. One station I visited had solved this problem by moving their operating station away from the wall so they had two access points. The front where you operate the station and the back where you test it. That way you get to have your cake and eat it too. The set-up worked really well. Picture a few racks with gear, an operating desk arranged in an L-shape, but moved away from the wall, rather than pushed into the corner. Space limitations prevented you from walking all the way around it, but you could get to all but one side of one rack. All this was arranged into the space of a standard spare bedroom, pretty much the same as most shack's I've visited. I find myself looking around my own environment with this front-and-rear idea in mind and I'm having a think about how I might apply it. Another observation is that we never ever throw anything away, ever. I have seen antenna projects that were doomed to fail from day one, spare screws, bits of wood, drawers and drawers of random electronic components, bits of wire, cut-off connectors, damaged bits of coax, half-wound baluns, empty tubes of silicone, failed micro-switches, bent wave guides, broken windings, arced air-gap capacitors, empty boxes, plastic bags, old radio magazines, all waiting for the day that they become useful, likely never. I'm not saying that this cruft is never useful. I'm saying that the chances of them being useful is inversely proportional to the amount. That means, the more junk you have, the less useful it is. Perhaps culling is a way to increase the usefulness of what's left. The ultimate example of something like this is a Go-Cart wheel bearing that I have lying on my desk. It's a piece of precision engineering, but it's stuffed. It has completed it's useful service life, was discarded in the dirt and I picked it up, cleaned it, oiled it and now it sits on my desk. It looks great, feels nice to play with, but as objects go, it's one of the least useful items on my desk, otherwise filled with paper, computer gear and radio gear. I just made the bold step to toss it in the bin. Not yet sure how I feel about it, but I'll try by saying that it's the beginning of making the remaining cruft on my desk more...

Amateur Radio Satellites ... more than two in the sky.

Nov 20, 2016 217


Foundations of Amateur Radio There are moments in your life when you say to yourself, duh, why didn't I think of this earlier? I had one of those last week. As you might recall, I have a hard time using HF communications from my home. There is lots of noise around and I've been going out mobile and portable to make contacts. As satisfying as that is, nothing beats sitting at home in your comfy chair with all the other home amenities. Ideally I have this notion that I should be able to do my hobby from home and have my cake and eat it too. Turns out, my duh moment was just that. I speak regularly on the local 2m repeater, in fact I host a weekly net called F-troop that encourages new and returning hams to get on air and make some noise in a friendly environment where no question is too silly and mistakes can be made on-air without subsequent yelling and carrying-on. So, I have a fully working HF radio at home, but it works just fine on 2m and 70cm. My duh moment was when I realised that there are a multitude of 2m and 70cm transmitters around that I could add to my tally of things heard and worked. There are websites dedicated to these transmitters and schedules exist to highlight when, how and where these things are. So, what am I talking about? The wonderful world of Amateur Radio Satellites. There are lots around, sending out idents, having uplink and downlink, sending out digital packets, you name it, the wide variety of Amateur Radio in a 90 minute orbit around the planet. I'll confess that I thought there were one or two doing the rounds, but there are a few more. Just counting the active ones, there are 85 satellites designed to be used by Amateurs at the moment, of course that changes all the time, going up and down as more are launched and others stop responding. In addition to this collection, there are other things you can listen out for, like weather satellites, the International Space Station and a bunch of other objects. I came across the N2YO website which shows you what's up in your sky right now, the foot print and direction, when it clears the horizon, in which direction and what the highest elevation is and when it vanishes again, all very helpful in getting half a chance to hear the transmission in the first place. I've said this before, this hobby is magic. I can't do HF, so now I'm playing with satellites. Looks like I'm going to have to sort out some digital decoding software as well, since many of the satellites have all manner of non-Morse code transmissions, APRS, digital modes, graphics, etc. Lots to learn. Did I mention that you could do much of this with a hand-held radio? Power is not a problem and an external antenna is likely all you'll need. By the way, this is what I like about Amateur Radio, there are so many different aspects to this hobby, so much variety, so many things to learn and experience and I have only just scratched the surface. It bears repeating that a beginner's licence in Amateur Radio gives you access to all this and most of the things I've been talking about since I started talking about the hobby back in 2011. I've been licensed now for a little more than a minute and a half, but I still get a pleasant surprise on a regular basis about the size and scope of my chosen hobby. There's no excuse, getting bored with Amateur Radio is just not an option. I'm Onno VK6FLAB

DTMF is something we use regularly ...

Nov 13, 2016 215


Foundations of Amateur Radio Ingenuity is the name of the game in Amateur Radio, building, inventing, solving and helping are all part and parcel of this hobby. We like to lay claim to being the source of all that is good in the world, all that was invented came from Amateur Radio first, right? Seriously though, sometimes we pick up a technology along the way from other places. If you've ever picked up your microphone and pushed one or more buttons on it whilst the push to talk button was down, you've likely used this technology that's set out in an ITU recommendation called Q.23. It has the quaint title of: "Technical Features of Push-Button Telephone Sets". It's a brief document as such, all of four pages, two title pages and one mostly dealing with why this Push-Button idea is a great one and how it relates to international phone calls etc. The meat is in the final page, showing eight frequencies and how you combine them to generate voice frequency signals. If you've been paying attention, you might recognise this as DTMF or Dual Tone Multiple Frequency signalling. It's pretty nifty. Send two discrete frequencies at the same time across some link and decode it at the other end. It's nifty because these frequencies might happen during a normal conversation, but not at the same time for a particular duration. As Amateurs we use this to communicate with our repeaters, to send signals to it, to activate links, to power on and off stuff and all manner of other interesting things. So, how does it actually work? Well, you have two sets of four non-overlapping frequencies which you can combine into 16 different combinations, enough for 10 digits, four letters and two symbols. To make this work, the frequencies must be pretty stable, the ITU recommends less than 1.8% off the nominal frequency and distortion must be 20 dB below the fundamental frequencies. Today producing such a thing is trivial, a chip for a dollar will do the job and another one at the other end to decode it. Four bucks and you're good to go for two-way DTMF at both ends. Bargain. Being the curios type I went looking to find out what a DTMF circuit might look like before we could buy such products. The closest I came was a build-your-own voice mail system in BYTE! magazine of April 1982 using LM567 tone decoders, but a quick look at the box shows that these are also something that we'd call an Integrated Circuit. I'm going out on a limb here, since DTMF has been around since it was first supplied to customers in 1963 and suggest that the original DTMF decoders were not quite as trivial as a dollar chip. They likely contained many discrete components including eight separate filters and ways to combine them so signals could be added to each other to detect the existence or absence of a specific tone, but I've yet to actually lay eyes on anything more fundamental than the tone decoders. That being said, you can connect your all-in-one dollar chip, the CM-8870, to something like an Arduino and do your own decoding of DTMF signals. Seems that the 1982 BYTE! magazine article was just the beginning of the revitalisation of DTMF, robot controllers, home automation, in-vehicle signalling and more, not to mention, using it to activate IRLP and other wonderful radio services. Before you start sending me email about this non-Amateur invention, I'll point out that Amateurs also didn't invent copper wire, that was two Scots, or was it Dutch, I forget, fighting over a coin. I'm Onno VK6FLAB

The joy of Amateur Radio

Nov 6, 2016 197


Foundations of Amateur Radio Last week over dinner I was chatting with a friend about Amateur Radio in a discussion about things that take your fancy. I was attempting to explain what it specifically was about this hobby that keeps me coming back. I talked about invention, about exploration, about fishing and catching that elusive station, but looking back over that discussion it occurred to me that none of that is what "does it" for me. Sure, those things are part of it, but it's not what makes me turn on my radio, what has my face light up in delight or allows me to get out of bed in the middle of the night to explore the bands. A brief phone call with another Amateur to wish him Happy Birthday twigged me to what's going on. He asked me: "What's new in your world?", and my answer, innocuous at best was: "Well, last weekend I heard a Japanese station from my QTH." In the past I've mentioned that I've made many contacts with Japan, looking at my log, 63 of them, on 10m and 15m, so the fact that I heard Japan wasn't particularly special. I don't recall the band on which I heard the station, so that's not it either. What was different was that I heard it at home, my QTH. The place where there is S7 or higher noise all the time, where I cannot put up a full antenna and make do with a dipole in the garage and a single band vertical on the roof. Looking back at the conversation it occurred to me that what I like about Amateur Radio is the unexpectedness of it, the surprises that come your way, like little gifts waiting to be unpacked. It reminded me of a journey coming back from a club meeting last year when I spent the time going through the entire frequency range of my radio. There's quite a bit to visit. The radio in the car does 100 kHz through to 56 MHz as a single range, then has several other ranges. My hand-held is capable of 500 kHz through 999 MHz. Between the two I have the ability to pick up most of the stuff that's around. If that's not enough, there are many online radio receivers to connect to using all manner of different tools, the simplest to get running is probably WebSDR, where you visit a web-page and pick out the frequency you want to hear. All this RF activity is happening all around us all the time. There's the local Top-40 radio station, the talk back shows, the local community stations, single frequency specialist broadcasters, the local public transit authority, etc. etc. You never know what you're going to find and what you're going to hear. Many Amateurs I speak to started off as short-wave listeners. I had a short-wave radio when I was growing up, but it never much did anything for me. Now that I'm an Amateur and I understand what's happening to make those distant signals arrive at my ear, I'm becoming the short-wave listener I never was. That's what I like about Amateur Radio. Unexpected gifts being shared across the globe from people, cultures and experiences that bring us all together. For me, Amateur Radio is about the thirst for curiosity, the never ending supply of wonder and the joy in hearing them arrive un-announced at my doorstep. I'm Onno VK6FLAB

Where do you start with this Amateur thing?

Oct 30, 2016 316


Foundations of Amateur Radio Being on air and getting on air are part of the journey that you undertake when becoming a Radio Amateur, but what happens before all that, what do you need to get your foot in the door as it were? If you're listening to this via a radio, you're already on the journey, but if you've downloaded this as a podcast, you're not far behind and your journey towards becoming a Radio Amateur is just around the corner. Let's start with a few things before I start with the journey itself. First of all, every country is slightly different, so while I can give you specific examples, they'll be valid for only a few people. In becoming a Radio Amateur you'll have to undertake some learning, pass a test and get a license. This license is specific to you and for most, if not all Amateurs, the license itself is for life. That means that if you have already passed an Amateur License Test in your past, you're likely still a Licensed Amateur today. Being a Licensed Amateur, or having a License, doesn't actually mean that you can operate your own station, for that to happen, you need a callsign and the requirements for a callsign are that you have a license. It's like learning to drive. Once you've passed your driving test you're able to drive a car, but you need a current drivers' license to actually get behind the wheel. In most cases there are different levels of license. Going back to the car analogy, you can drive a car, a moped or a truck, but not with the same license. In Amateur Radio there are several different types of licenses. For example in Australia there are three, in increasing level of responsibility, a Foundation License, a Standard License and an Advanced License. In the United States there are also three, The Technician License, the General License and the Amateur Extra License. In the United Kingdom there are also three, the Foundation License, the Intermediate License and the Full License. Germany has two types and calls them Class E and Class A. In essence the idea is that with more learning comes more responsibility and a change of license. To muddy the waters a little, as time passes and Amateur Radio evolves, license types change and merge, new ones are introduced and old ones vanish. For example, to my knowledge there are no countries requiring Morse Code as a skill for an Amateur License. That wasn't always the case and until 2003 the World Radio-communication Conference essentially left it to individual countries to decide if Morse Code was a requirement for specific privileges. As an aside, Citizen Band or CB, where anyone can walk into a shop, buy a CB radio and use it without passing a test and getting a license is fundamentally different in that the license is linked specifically to the radio itself. There is still a license, and to operate, the license needs to be current, but it's intrinsic to the radio itself. Amateur Radio has the license linked to the person, rather than the radio. Now that you know a little about the landscape, the next step on your journey towards becoming an Amateur is a little less nebulous. It's probably a good place to start at the beginning and work your way through that and as time goes on and your confidence and experience improves, to add to the learning and do the next thing as it occurs to you. I should point out that there are Amateurs who believe that it should be your goal to get the highest level of responsibility, but my perspective on this is quite different. This is a hobby, your hobby. If you want more responsibility, then go do some learning and pass a test. If you're happy to do what you're doing, then do that. Don't let anyone tell you that you must increase your learning, just because they tell you to or that it's the done thing. For me, I've set a personal goal to work a hundred countries using 5 Watts and every contact I make counts towards that. If you've been listening for a while you might have noticed that I've not...

What happens if you move the feed point in a dipole?

Oct 23, 2016 255


Foundations of Amateur Radio One of the recurring topics in on-air discussion is that of antennas and if we were to graph the topics of conversations, antennas would be the clear winner in any line-up. As a beginning Amateur this phenomenon bamboozled me for a very long time. Why are these people talking about antennas all the time and what's there to know that you can't say in 30 seconds? From the mouths of babes... I've mentioned in the past that Amateur Radio is to a very large degree magic. Another way of expressing that is to say that there is an Art to being an Amateur and antennas play a big part. A friend of mine loaned me his antenna kit called a Buddipole. It's a portable set-up that is akin to Meccano or Lego in that you can build up an antenna from parts and make a large range of antennas from the same basic parts, two coils, a feed point, a balun, two telescopic whips and some extension pieces. For me this particular antenna has been temperamental and I couldn't get my head around how to make it work. This all changed last weekend when I had a spare 15 minutes, literally, 15 minutes when I went into the shed to have another look. This was spurred on by a note that I'd read that pointed out that the Buddipole is asymmetric, that is, both legs and coils are not the same. This important tid-bit of information made things click in my mind and all of a sudden I realised that I didn't need to make both sides the same length, or adjust both sides in the same way. Until that moment I'd always thought of the Buddipole as a dipole on a stand and expected like any traditional dipole it would have both legs at the same length. What if you could move the feed point along the length of your dipole, what would happen? What if you kept the overall length the same, but by making one end longer and the other end shorter, you in effect were moving the feed point along your dipole? Wonderful things start to happen, that's what. What I'm saying is that you don't have to make a dipole have equal length legs and that sometimes this is desirable. Previously I've mentioned that the height of a dipole, the wire thickness, the ends, the angle and so on all affect the feed point impedance. Turns out, that where you place the feed point also affects this. If you recall basic antenna theory, you might recall that the middle of a dipole is the lowest impedance and that the end of a dipole is the highest impedance. Each of these values are on a continuum, that is, they vary as you change things. That means that between the two extremes of impedance there are other in-between values. If you have a balun, you can use this to get a great match for your antenna by tweaking these values. Another example of this continuum is a loop antenna. If you make it twice as high as wide, the feed point impedance is 50 Ohm, but if you use the same loop and squash it flat, the impedance is 300 Ohm. Varying the shape changes the impedance. In essence this means that there is an infinite number of antennas that can be made just as a dipole and another infinite number of antennas that can be made as a loop. So, just two antenna types alone already gives you a lifetime supply of options and that's ignoring the height, soil or wire. Now you understand why antennas are tricky and why we talk about them so much. It also explains why the Internet is full of different explanations on antennas, since they are all based around the local conditions under which the author is describing their adventure. Next time you hear an Amateur going on about their antenna, perhaps there's something to take away. I know I won't be anywhere as impatient listening to others talking about their contraptions. Final thought. A vertical is a dipole too. The radials are one half, the vertical the other. You can change the length of either, or both, but you can also feed the antenna in a different location. I'm Onno VK6FLAB

DX, common ground on a common term?

Oct 16, 2016 253


Foundations of Amateur Radio Have you ever been on air and in the middle of a wonderful discussion that all of a sudden and often unexpectedly erupts into a heated argument about nothing? One of those conversations that came to mind was about what the term DX means. I'd been taught that DX means outside the country and if you're calling CQ DX, I was taught that this means that you're looking for a contact in the next country. So. What's the argument? Simple really. In a nutshell, making a contact between Perth and Sydney, nearly 3300 kilometres apart is inside one country, but making a contact across the same distance between say Amsterdam and Lebanon, is about nine countries away. This really means that for every station DX has a different meaning. So, this DX caper means different things for different people. I've said in the past that I'd laughed when a station made a big deal about contacting Japan, when that's something I do regularly. The opposite effect happened when I contacted Cuba. For me it's a contact on the other side of the planet, for them it's next door. I asked around for explanations from others about what they thought DX meant: - Receiving signals & station from remote locations - Long distance, harder to achieve contacts. - Doesn't have to be international, all frequency dependant. - VK[234] to VK6 is DX ;) - Outside of my suburb ! - Anything hard I suppose, or anything "overseas" The take away should be that DX-ing is an activity that means different things to different people. You could put it down to kilometres, or countries, it really doesn't matter. Just be prepared that your measure may not apply to the other station. Ironically, thinking back to one of my earlier on-air experiences. I called CQ-DX and got a reply that said something along the lines of "What kind of DX are you expecting?" to which I replied: "Anything I can get." is put into a different context by the knowledge that DX is not a fixed idea. At the time I thought that I had done something wrong and that my activities were some how incorrect. Checking with the amateurs nearby at the time, it transpired that this wasn't the case. My insight into the variation of something that looks like a simple concept, DX, puts a different light on the subject. I'm highlighting this because I think it's important to understand that when you're on air, you're bringing with you the experiences you have and you're communicating with others who may, or may not share those experiences and understandings, even for something as obvious and common as the concept of DX. It also spurs me on to continue to develop my QSL card. If you've sent me one and I've not sent you one back, it's because I'm still very unhappy with the design I've got and I'm working on something that's more me, more Australia and captures the essence of the idiosyncrasy that is me. If you're wondering what a QSL card is, think Amateur Radio Postcard. The name derives from something called the Q-Codes, shortcut names used originally in telegraphy, then by Amateurs in Morse, now also heard in all general conversation on air. The code "QSL" means "Can you acknowledge receipt?" when asked as a question, or it means "I am acknowledging receipt." when used as an answer. The card was named after this as a way to confirm contacts between stations. A QSL card generally contains your callsign, their callsign, the time, date, the band or frequency, the mode and signal reports of the contact. Some go overboard with whole novels, include general information about the station, perhaps a picture of your friendly face, or some other image. Traditionally, interesting locations, like say Amsterdam Island, activated as FT5ZM go all out in making their cards, since the location is desirable and the card should be as well. One final comment. To work DX, you need to be on-air, so get your station in good working order, turn it on and make noise. Making contacts, local and DX is about being...

Propagation is everywhere!

Oct 9, 2016 205


Foundations of Amateur Radio Recently I talked about making a propagation map in your mind by listening to the various NCDXF beacons across the globe on various HF bands. You're not limited to listening to a beacon to learn what propagation is like. If I tell you that listening to a band gives you an indication on what's going on, you're likely to respond with: "Duh". But what if I suggest that instead of listening to a DX station running a pile-up, you instead listen to the stations calling? Back in January 2014, episode 133, when this series was still called "What use is an F-call?", I explained what "Listening 10-up" means and how you operate in a so-called split mode. As you might recall, working split is about dealing with the phenomenon that a weak DX station working in some desirable location is likely to be overwhelmed by stronger signals, to the point of no longer being heard. It's a good skill to learn and you should try and work both sides, being the station calling a DX, but also being the one getting swamped. As I said, normally you're the one calling the DX station and you don't particularly care about the other stations swamping the band. What if you did? What if you used their signals to figure out where propagation was happening? If you did that, you could perhaps point your antenna in the correct direction, or specifically focus on calling for stations in that area, or listen out for stations in that region in other parts of the band. The thing is, propagation doesn't care what the signal is. As long as you can decode it in what ever way you prefer, Mark I ear-drum, or some fancy decoder, it doesn't matter. If you can hear the signal, it means it's getting from them to you. I should note a word of caution here. It's taken me several years to realise that I could often hear many stations that had no chance of hearing me. I'd crank up the volume on the radio, listen out for anything and try to work what I heard. Sometimes you get a great result, and you shouldn't discount those, but often all I got for my trouble is a sore head from decoding mush. What I learned, especially as a low power operator - I use 5 Watts - if the other station isn't coming in with a reasonable signal strength, S5 or higher, then there's little point. There is a concept of reciprocity. The idea is that if you can hear them, you can work them. For some power levels that might actually be true, but for the rest of us, a fine grain of salt should be added to the mix. Before you start in on me telling me I'm wrong, perhaps consider the variations in local environment, antenna differences, not to mention variation in the Ionosphere or alligators, all mouth and no ears running several kilowatts. The take-away in all this should be that propagation is everywhere. You can use it to hunt for likely contenders and no signal on the band should be ignored as a potential source of propagation information. One final thought. You can also reverse this. Turn on a web based receiver in some desirable part of the world, pick a frequency and then using your radio, call CQ and see if you can hear yourself across the web. I'm Onno VK6FLAB

The birth and legacy of IRLP.

Oct 2, 2016 259


Foundations of Amateur Radio Technology is a moving feast. New ideas spring new inventions which in turn change our lives. Amateur Radio is at the forefront of such inventions. Radio Amateurs have been until recently the only soldering iron brigade around. We've been building things for over a hundred years and we continue as a community to think of new ideas and ways to make them happen. For example, we take technologies like AllStar Link, EchoLink, Wires and so on all in our stride. We think nothing of having our radios connected to each other using techniques other than radio spectrum. In November 1997, when iPhone still meant Internet Phone, an inquisitive 22 year old amateur called Dave Cameron VE7LTD came up with a way to link a radio to the Internet and the first three Internet Radio Linking Project stations were connected to each other and the now global network of IRLP nodes was born. Dave built a DTMF decoder which allowed remote control of a computer and the radio that was attached to it, and made it possible to send the audio from the radio to the sound-card of the computer, which in turn sent that audio in digital format across the Internet to a similarly equipped system where the audio was turned back into a radio transmission. This bridging idea took off and many different systems were developed, many of which are in active use today. The various systems all use some form of Voice over IP to transmit audio across the Internet, but there are many variations on how the audio gets to the system in the first place. In IRLP - as I mentioned - the audio can only come in via an Amateur Radio. EchoLink uses a similar system, but in addition to Amateur Radio as a source, you can register your callsign and use several different applications on your computer or mobile phone to link into the network. AllStar takes this idea further, instead of making a point-to-point connection, the AllStar system is based around an open source telephone exchange called Asterisk and it's used to link together the various systems. Other variations also exist. The idea of using Voice over IP techniques spawned a whole set of radio technologies that use similar methodologies to compress voice and then instead of transmitting it across the Internet, use radio waves to send them from one radio to the next. Technologies such as D-Star, System Fusion, MotoBro and DMR built on this idea. Of course these technologies also use the Internet to share information and connect users across the globe. There is some contention around these systems. Many Amateurs consider them to be "Not Real Radio", but then I suspect if you look at the birth of SSB, you'll find die-hard CW operators with a similar complaint. The same is true for low power propagation modes like WSPR which aren't real radio because you cannot have a QSO. Other issues in the technical sphere also exist. The IRLP software is closed source. You can only buy IRLP hardware from one place and it doesn't allow you to connect in any other way than via a radio. EchoLink now charges for conferences being registered in the system. In the past I've already spoken about Fusion, D-Star and MotoBro and their restrictions around interoperability, licensing and closed source nature. From a practical perspective, there are also concerns about the use of these systems in the case of massive failures during local disasters and the like. If the Internet is down, many of these systems will simply become local radio networks. Coverage could perhaps be extended by creating a local mesh network, but HF radio still very much has its place in our world. For me this is all about learning and innovation. Ultimately which system you use is up to you. I live in a software world where Open Source rules for good reason and my vote will always go to Open Source. To be clear, I'm not adverse to making money, we all have to pay the rent, but making innovation and invention secret is not the way to go in our...

Make your own propagation map!

Sep 25, 2016 176


Foundations of Amateur Radio The world is your oyster, but sometimes you need to find a way to test what is going on with your station and determine what is working and what isn't. Often I turn my radio on to scanning mode and I set it to scan the Northern California DX Foundation beacons. These beacons, perhaps better known as the NCDXF beacons can be heard across five different HF frequencies, on 20m, 17m, 15m, 12m and 10m. These beacons repeat in a cycle that lasts three minutes, covering 18 different transmitters located in countries scattered around the globe. Beacons exist in New York City at the United Nations, in two other locations across the US, in Canada, New Zealand, Australia, Japan, Russia, Hong Kong, Sri Lanka, South Africa, Israel, Finland, Madeira, Argentina, Peru and Venezuela. Each beacon rotates through each frequency and then waits three minutes to transmit on the same frequency again. Each transmission contains the station callsign, sent in 22 words per minute Morse code, followed by four one-second beeps. The callsign and the first beep is sent using 100 watts, the next one uses 10 watts, the third beep is sent with 1 watt and the final one uses 100 milliwatts. What this does is give you a pretty accurate map of what you can hear on what frequency at this time with your station. Another way to think of this is as a propagation map that actually uses your station as the receiver. If you can't hear 'm, you can't work 'm. If your radio doesn't scan across frequencies very well, there's nothing wrong with listening on one frequency for 3 minutes, switching to the next and so on; 15 minutes later you'll know what propagation is like around your station. You can find full details about this whole beacon system on ncdxf.org and I should mention that there are many other beacons around that provide signals for you to listen to. As an aside, this system is precisely what prompted me to start the process of learning Morse Code. I'm still at it and you should not take my slow progress as anything other than me being distracted by the other things that are happening in my life. If you need something more active and participatory to get a sense of the operation of your station, you should have a listen to the 7130 DX net. It happens every Monday, Wednesday and Friday at 9:30am UTC on 7.130 MHz +/- QRM. Next time I'll talk about how that works and what you might gain from having a go. I'm Onno VK6FLAB.

How to melt coax ...

Sep 18, 2016 182


Foundations of Amateur Radio Recently I made a comment about melting your coax and that this was a bad thing. Today I'm going to talk about some of how this comes about and what kinds of parameters we're dealing with. Let's start with coax itself. The operating temperature of coax is somewhere around 80 to 90 Degrees Celsius, or 176 to 194 Fahrenheit. Soldering is at 230 Celsius, or 446 Fahrenheit, so for starters, soldering coax is a risky adventure. For argument's sake, let's assume that you managed to solder your coax without damaging it. What else can go wrong? Let's have a look at high voltage transmission lines. Why do we move power around the place using high voltage lines? The answer is that in a high voltage line, the current is low. Where the current is low, heating is low, so more of the energy gets from the power-station to your shack and less of it is used to heat up the power line between the power station and you. So, that means that high voltage and low current is less heat loss. The opposite is also true. Low voltage and high current is more heat loss. Now if you look at a dipole antenna, you'll know that this contraption is moving energy around at some or other frequency. As it's doing that, there are high and low voltage points and high and low current points. In a half-wave dipole, the high voltage points are at the ends of the antenna, and the high current points are at the feed-point. Guess where your coax is? So, you've got your connection to your antenna located at a high current point, in the place where high current has the potential to create problems, things like heating up your coax and potentially melting it. So, when does this heating happen? Well, you need high resistance and high current. This typically happens when you've got a bad connector at the feed-point. In practical terms this means that if you're using QRP, 5 Watts, you're unlikely to come across a situation where this becomes an issue, since the currents aren't that high and a bad connection typically means no contacts. If on the other hand you're using high power, then make sure that the connection to your antenna is strong, solid, and water proof so it doesn't deteriorate to the point of melting and then killing your radio. It's best to keep an eye on the SWR meter when you're working, since a high SWR might be indicating that the resistance at your antenna changed for the worse. Final comment. When you've set-up your station, create a note of the SWR at different frequencies and refer back to that regularly. Spotting a problem early might just prevent some expensive maintenance later on. I'm Onno VK6FLAB

What is SWR?

Sep 11, 2016 327


Foundations of Amateur Radio Today I'm going to talk about SWR or Standing Wave Ratio. As amateurs we use this term all the time, we expect to see it on a meter or display near our transmitter, we buy specific gadgets to measure it and often we seek to find the lowest possible SWR. As I've said in the past, the perfect antenna cannot exist, in the same way, a perfect connection, the feed-line, between an antenna and transmitter can also not exist. The perfect match is a 50 Ohm match, but a dummy load is a perfect match and its purpose is specifically not to radiate. So what's all this about then? Lets start in a swimming pool for a moment. Imagine that this pool is really long and skinny. Say 100m long and 1cm wide. Stand on one side and make a splash. The ripple of the water radiates from the source of the splash, you, to the other end of the pool. The end wall bounces the ripple back to you, and bounces back and forth until all the ripples have dissipated. Now, if you kept splashing about, and waves were rippling back and forth while you were splashing, some of the ripples would happen at the same time as a splash and some of the ripples would happen at the time between two splashes. That means that at some times the splash and the reflections would sit on top of each other, making a higher wave and at some times splashes and reflections would be sitting below each other, making the troughs between splashes deeper. If you replaced the water with electricity and the pool with a transmission line, the same is true. If you made an electronic splash, say a transmission from your radio, into the feed-line, the ripple would travel along the feed-line, bounce off the end, come back, bounce off the radio and so on. In the same way, reflections and transmissions can add to each other, and they can also subtract from each other. This difference between the addition of signals and the subtraction of signals is what we call the SWR. There are two ways to get to the SWR. If you connect a 50 Ohm feed-line to a 100 Ohm antenna, the SWR is 2:1. This is a theoretical SWR and it tells you is that there will be a ripple coming back from the antenna that is both adding and subtracting from the original transmission. Alternatively we could use an SWR meter to measure the voltage differences between the high and the low part of a wave and indicate on a dial what the SWR is. This is an actual SWR. The two are indicating the same thing and we can use that to get from a measurement to an understanding of impedance matching between the feed-line and the antenna. As a point of reference, if there are no ripples bouncing back, then there is no addition or subtraction, and the resulting SWR is 1:1. For completeness, I should point out that the rabbit hole is much deeper than this explanation and I'll revisit this topic in the future. Now for the final piece of the puzzle. A piece of coax in Amateur Radio is 50 Ohm. If you have an antenna that is 50 Ohm, that's perfectly fine as an antenna system. Of course, antennas are not so accommodating. A dipole has a feed-point impedance of about 75 Ohm. A folded dipole has a feed-point impedance of about 300 Ohm. Each different antenna system has a different impedance and thus needs a different transmission line connected to it. So, if you look at a 50 Ohm coax connected to a 300 Ohm folded dipole, you know that the SWR is going to be 6:1. However if you connected a 300 Ohm ladder-line to the same folded dipole, the SWR would be 1:1. What this means is that the coax would have waves rippling back and forth and the ladder-line would not. The coax would have a particular loss and each ripple going back and forth would be subjected to that loss, where on the ladder-line, the loss would only apply once, on the outbound leg, since no energy would be bouncing back. As an aside, this loss is experienced as heat and if you're not careful it will melt your coax or worse. That's not to say that SWR...

What is station security?

Sep 4, 2016 175


Foundations of Amateur Radio One of the tick boxes we're required to deal with is the one titled "Station Security". As licensed amateurs we're required to secure our station from use by unauthorised people. What form does that take, how do you do it, what makes it secure and how much security is enough? I spent a bit of time looking around to see if there were any guidelines I could unearth to actually describe in detail what this might actually mean, but my Google Fu is clearly broken, since I was unable to find any such documentation. That's not to say that it doesn't exist, just that it's well hidden among the hits about encryption, broadcasting music and other spurious results. What form does this requirement take in your shack? Do you tick the box and move on, or have you taken specific actions to comply with this requirement? For me, I have two shacks. One in my office and one in my car. Taking the car first, the security of my mobile shack is based around the notion that my car is locked when I'm not around. Technically my partner also uses the car and it's not directly under my control at that time, but the flip side of that is that the radio needs to be manually connected to a battery, the head of the radio needs to be connected to the patch lead, the antenna needs to be screwed in and the coax switch needs to match the band you're trying to operate on. These things are not complicated for an amateur, but for a member of the public they form several barriers to entry before they could actually operate my station. In my office, where I mostly operate on VHF due to the high noise level on HF, security takes a similar form. It's in a locked house, that is, if I'm not home, the house is locked. Similarly, when my partner is around they technically can get to the station. The same is true for any guests to our house. Security again is a multi-level activity. The radio needs to be connected to power, the antenna needs to be connected to the correct port, the remote head needs to be connected correctly and if all that is done, you can operate my station. There are no specific locks on my radio; the same is true for any station I've ever visited. All of the clubs I'm a member of have a room or a box with a lock on it which is one barrier, but once that is breached, the radio behind it is good to go. This whole topic is an example of how we legislate for a particular thing, in this case preventing use by an unauthorised person, but don't actually specify what that means. So, what type of security does your station have? What's enough security and what isn't? Is my station legal or not? What makes it so? What about your station? It's easy to read the rules and tick the box, but sometimes the tickbox is a deep rabbit hole. I'm Onno VK6FLAB

Unpredictable radio waves ...

Aug 28, 2016 152


Foundations of Amateur Radio Radio Waves travel in straight lines. They go from point to point and that's it. Except that Radio Waves also reflect off certain surfaces, like light does. So, Radio Waves travel in straight lines and they also reflect and that's it. Except that Radio Waves also change direction when they pass through some change of medium. So, then, Radio Waves travel in straight lines and they also reflect and refract and that's it. Except that Radio Waves also bend when they encounter an obstacle or a slit. So, ok that's it. Radio Waves travel in straight lines and they also reflect and refract and diffract and that's the end of it. Except that they turn slightly due to gravity when they pass by a large mass. So, this phenomenon that we use in our hobby every time we key up a transmitter or listen to an off-air signal is doing much that is invisible. It bends and wobbles, bounces and shifts, reflects and refracts and somehow we still manage to make our signal get from here to there. The reason I'm raising this at all is that all new entrants to the hobby often scratch their head when they start transmitting. Antennas and propagation aside, the humble hand-held portable radio, the walkie talkie, or handitalky, or whatever you call it, does some weird stuff. Some people use it like a mobile phone, other talk into it like they're summoning the oracle, others wave it about and hover around metal doorways or hold it close to their body and walk about while they're talking. I host a weekly radio net, you should check it out some day, Saturday Morning, 0:00 to 1:00 UTC, it's called F-troop and we get lots of different skill levels and experiences sharing stories and answering questions. Many times we have amateurs who are using a hand-held and getting unexpected results. This variable, fluid nature of radio waves is why this happens. Each tiny variation causes some effect and some outcome. Resulting in a wildly fluctuating signal that varies between loud and clear and inaudible and all steps in between. And that's not even talking about flat batteries or trying to talk through a hill to a local repeater. My point is that radio waves are unpredictable. If you are using your radio in an unpredictable way while using an unpredictable medium like radio, then all bets are off. Next time you key up your hand-held, spare a thought for what's happening between your antenna and mine. I'm Onno VK6FLAB.

Learning from your mistakes ...

Aug 21, 2016 154


Foundations of Amateur Radio To do the same thing over and over again and expect a different outcome is the definition of insanity; so how do you avoid making the same mistakes on-air in Amateur Radio? During the week I was wading through some old photos and videos on my phone to make some space and I stumbled on some old videos taken by others and sent to me whilst I was on-air. It was a lovely look back at some previous activity, but they also made me cringe. Here's one example, the very first time, back in 2011, I did a local contest, using the club callsign VK6AHR: == One One. My number to you is uh, one zero four, uh V K Six Alpha Hotel Romeo to V K Six Alpha Romeo, my number to you is one zero four. == It's only that I know I was using the club callsign that I know who I am and who the other station is, in this case the other station was VK6AR. My exchange was 104, but clear as mud and twice as thick. These days I'd say something much less convoluted, something like: VK6AR, 59104 from VK6AHR Here's another attempt from me in my early days, calling DX using my own callsign: == "CQ DX, CQ Delta Xray, this is Victor Kilo Six Fox Lima Alpha Bravo calling CQ DX" == CQ Delta Xray, what was I thinking? Actually, I was emulating another amateur. So what you say, while there are new amateurs in your shack, matters. Also, I noticed that I started the bad habit of saying Fox instead of Foxtrot. Fortunately one of my listeners wrote in to nip that in the bud early on. My point in sharing these evolutions of my on-air style is that you might experience me as a practiced amateur, but just like you, I had to learn by making mistakes and being told I was making mistakes. Fortunately there was some video evidence to help in my innocent education stages. So, from your perspective, next time you get on air, try and record some of your activity and have a listen back. I've done this with new amateurs and old-hands and it's absolutely staggering how much you learn from having a listen to yourself. So, when you get on air to make some noise, record it for education purposes and listen back. I'm Onno VK6FLAB

Paper Logging tips and tricks ...

Aug 14, 2016 186


Foundations of Amateur Radio There was a time when I took my computer out into the field to do my portable logging. That's still true for contests, but when I'm hunting for an elusive DX station, I no longer take with me all the bits that are required to make that level of technology work. I've come to the realisation that less is more. Especially with portable operations in parks and on summits. This move to paper will actually simplify your life whilst you're enjoying the rare stations you can hear. So, if you're using paper logs and you are wanting to make actual contacts, how do you do this without going insane? Normally you'd find a station, log their call, put down the frequency, scratch it out when the contact failed, rinse and repeat. The end result is a page full of scratched out callsigns with no structure and little chance to accurately log these into your normal station log. The best way to overcome this is to take a leaf from N1MM, a brilliant piece of logging software that deserves a whole separate segment and when I'm sufficiently proficient with it, I'll do just that. In the meantime, one of the things you can do with N1MM is mark a station. This mark consists of a callsign and a frequency. Technically it also consists of a mode and a time-stamp, but lets not get too carried away. On paper, if you format your log-sheet appropriately, you can use a separate line for each station you hear. Log the frequency while you're writing down the callsign. If you're inclined, you can also write down their name and any other salient details you hear as you're browsing past. What this does is set up a framework for you to log your calls. When you actually make contact, then you can enter the signal report and the time. That way you can instantly see which of the lines contain actual contacts and which of them contain stations heard. Sometimes I write down their signal strength as I note the station, but that's a pretty variable thing, so do that in moderation. When you've actually completed the contact, make a mark, either an exclamation point or two, or an asterisk, or something that you recognise. That way when you're sitting in front of your station log, you can quickly log those specially marked contacts and add them to your DXCC tally. This same technique works well during search and pounce operation during a contest, though I personally am unlikely to use paper for contest logging; N1MM is very helpful in keeping track for you. As a bonus, N1MM allows a station to expire, so your screen isn't filled with stations that are no longer there. I should point out that I'm making the assumption that you're the one responding to another station, rather than sitting on a frequency calling CQ. If you're doing that, just log their callsign as they come past, keep track of the time and write down any signal reports when they're happening. That way you don't get ahead of yourself and you'll end up with a log that still makes sense later on. Logging is important for your own benefit. Some jurisdictions require a station log, for others it's optional. If you're interacting with other stations, logging their call is a courteous thing to do. I'm Onno VK6FLAB

The FM Capture Effect and other Amateur Radio magic...

Aug 7, 2016 220


Foundations of Amateur Radio Today I'm going to talk about magic. In the past I've made mention of the magic that is Amateur Radio. There are those who think that our hobby isn't magic and that everything that we do in this field is understood and documented. I think that this is both wrong and unhelpful, since there is much to learn, much to discover and much to invent. Amateur Radio isn't dead, it's full of life, full of things that are continuing to develop, evolve and grow. Let me give you an example. In radio there is a phenomenon called the "FM Capture Effect". Explaining how you experience it is simple. If you have two FM transmitters on the same frequency, and you're using an FM receiver, one of the FM transmitters will win, that is, you'll hear one and not the other. Unlike in AM and SSB transmissions, where you hear both at the same time, the FM Capture Effect causes the receiver to pick one over the other. As an aside, it's because of this effect that aviation and HF communication mostly prefer AM based communication. Imagine two pilots trying to talk to the tower at the same time, one is heard and the other not. Back to the magic. We can describe that this thing happens. We can show it happening, we can even measure the signal strength difference that causes it to happen, 0.17dB according to one document I read. We can use formulas to describe our FM signal, we can use simulations to emulate it, but in the end, the closest we can get to the how and why is: This happens, we know it happens, it happens under these circumstances, but precisely how, we're not sure. A thesis I read on the subject by Park Soon Sang at the Naval Postgraduate School in Monterey, California, published in 1989, spends many pages saying all these things and finishes off with: "The simulation results establish that the low pass filtering portion of frequency demodulation accounts for the capture effect of FM receivers." and goes on to say: "It is recommended that the capture effect be verified using an operating experimental system in which system parameters can be controlled and accurately measured." Or in other words, we built a software simulator to learn about this phenomenon. This simulator suggests that the low pass filter causes this, but you really should make an actual set-up to test this. If I'm less vague, we simulated it, it looks right, but we're really only guessing, so test this in the real world. Now, before you get all huffy. I'm saying that a phenomenon that has existed since the first FM transmission in 1936 is still being explored and investigated and the jury is still out as to what precisely causes it and what the parameters are. As Arthur C. Clarke wrote in 1973: "Any sufficiently advanced technology is indistinguishable from magic." -- by that definition, Amateur Radio is clearly magic. So, when you next scratch your head about what the future of our hobby has in store, the answer is almost certainly covered by the very same author: "The only way of discovering the limits of the possible is to venture a little way past them into the impossible." Amateur Radio, it's magic and there is more to discover. I'm Onno VK6FLAB

Don't ever yell into a microphone and other neat things ...

Jul 31, 2016 284


Foundations of Amateur Radio This technology driven community of radio enthusiasts makes me laugh on occasion. Today I had to laugh when I realised that we spend an awful lot of time talking about antennas and radios and feed lines and impedance and propagation and electronics and a whole lot of subject in-between and around that. It stuck me that one conversation that we don't have, is the one about microphones. Specifically how to actually use one. I've been around hundreds of radio amateurs, seen them speak into their microphone, witnessed them standing at a lectern presenting their latest project, observed them attempting to rally the troops during a HAMfest by yelling into a microphone and heard them on-air. I came to the realisation that despite our familiarity with the technology, by enlarge, the amateurs I observed are no better than the general public when it comes to using a microphone. Actually, I think as a community we're worse, because we won't be told how to do it. So, I'm going to tell you. You can switch me off, or in the secrecy of your own shack, stick around and see if there is something to learn. I'm coming at this from a background in broadcasting. I've conducted some 1800 interviews in my time, have spoken in public, on-air and in myriad different environments, including large event venues and sports arenas. I won't say I've seen it all, but I've seen my fair share of how it's done, what it sounds like and what doesn't work. The very first thing to note is that yelling into a microphone will make it worse. Let me say that again. Don't ever yell into a microphone. The second thing to note is that you should keep the distance between your mouth and your microphone as static as possible. A good rule of thumb is to clench your fist and put it between your chin and the microphone. That's the distance that you should start with. Some microphones need you closer, others need you further away. Eating your microphone is only for very experienced operators in specific environments, since every thing your mouth does will be captured. A microphone is in essence a device that converts movement into electricity. This sounds obvious, but it means that waving the microphone around is also movement. The cable that's attached to the microphone moves, and makes sound. The desk on which the microphone is placed moves when you touch it, that's sound. Anything you can hear with your ears and much that you cannot, will be captured by the microphone. Not all microphones are equal. The ideal microphone converts all frequencies equally well, but this isn't actually possible, so, some frequencies are better captured than other frequencies. This means that your voice will not actually be captured in exactly the same way as it comes out of your mouth. Speaking of which. What you hear from a recording of your voice often sounds wrong. This is because the sound that's coming from inside your mouth is also travelling inside your head and your ears pick it up from the inside as well as from the outside. Listening to a recording of your voice doesn't echo inside your head. On an FM repeater, if your signal is captured by the repeater, the volume is not due to your antenna, it's due to your microphone. So make sure you set the microphone gain appropriately and when people tell you that you sound soft, fix the gain. Microphones will pick up breathing and the sounds your lips make when you smack them together and when you say the letter P as in PaPa. The best way to deal with this sound is to learn not to make it. In the mean time, you can speak across the microphone, rather than directly at it. This means that you should keep the same distance, but tilt the microphone slightly. Speaking into a lectern microphone, a radio microphone or a hand-held all follow exactly the same principles. If you get the opportunity to hear yourself via headphones while speaking into a microphone, use it to listen to what exactly is captured....

The band is dead and there are no contacts to be made...

Jul 24, 2016 203


Foundations of Amateur Radio There is a curious phenomenon related to how we operate that is pervasive within our community. As an inexperienced ham, I would turn on my radio and tune around and hear nothing. I'd change bands and do it again. Over time I'd work my way through the bands I'm allowed on and find no activity. On rare occasions I'd venture into the wide unknown and see what other bands were doing, ones where I wasn't allowed to transmit due to my license restrictions, and find lots of people talking to each other, making noise and having fun. More often than not, this band of feverish activity was 20m. For a long time I ascribed magical properties to this 20m band. There was always propagation, people were always there and it seemed that if you wanted to make contacts, that was the place to be. Over time I participated in contests with other amateurs, operating a club station and finding myself on 20m making contacts. I began to believe that 20m was this amazing place where stuff was always happening. This seemed to be reinforced by other amateurs who would use as their sole reason for gaining extra responsibilities, access to the 20m band. Now before you start, 20m is special. It has some interesting properties which make contacts appear and vanish at short notice. Just like other bands with their different peculiarities, practice makes perfect. But, 20m isn't that special. It's not a band that is always open, or always closed, just like 15m isn't, nor is 10m, neither is 6m, 80m, or 160m or whatever band you prefer to operate on. No band is always open and no band is always closed. Guess how I know this? Whenever there is a contest, activity blooms all over the place, the bands are full of stations, making contacts, having fun and annoying those stations who hate contesters with vehemence, so, clearly there is something else going on. There is. It's you, and me, and everyone else. We're all listening. While listening is good, you also need people to talk, otherwise there is nothing to listen to. There are automated stations around using beacons and WSPR modes and all manner of cute software to determine if their station is being heard. And if you look at the maps, they clearly are being heard. So, as I've said before, go on air and make some noise. If you want to make contacts, you need to make noise. Your friends need to make noise. You need to setup regular contacts with friends somewhere on the planet and actually use the bands. Yes, having access to 20m is fun, but lamenting that is frankly a waste of time. Whatever band you're on, whatever you're doing, you need to make noise. Yes, of course there are variations in propagation throughout the day and the solar cycle affects how far and wide you'll be heard, and sun spots and solar flares affect the ionosphere as well, but it's not the only variable. Just because no-one is heard, doesn't mean that no-one is there. So, repeating myself, go on air and make some noise. I'm Onno VK6FLAB

How old is the mode you're using?

Jul 17, 2016 197


Foundations of Amateur Radio The thing I like about our community is that there is always something new brewing, someone is inventing something, making something or doing something. It amazes me that the level of ingenuity is boundless. During the week someone asked the question, "What's the difference between AM and FM?" and while answering that could incorporate hand waving, arrows and drawings, I came across a much simpler explanation, which simply says it all. Credit goes to redditor EmmetOT. Imagine replacing radio with light, this isn't a stretch, since it's part of the same spectrum. Replace a radio transmitter with a light bulb. AM is using a dimmer, changing the brightness, to send information. FM is changing the colour of the light to send information. I could stop right there, but there is so much more going on in our community. If you've been out of Amateur Radio for a while, and I know, this happens to the best of us, you'll be forgiven in thinking that nothing is the same as it was, while wondering if anything ever changes. Both these things are true and I think that's good. The first AM voice transmission was made in 1900, SSB experimentation began in 1915 and FM experiments were happening in the early 1930's. These three modes, AM, SSB and FM are still with us today. We've done other cool stuff since then, stereophonic and quadraphonic FM. We think of RTTY as a relative new kid on the block, but it has its origins in 1874 and the first on-air RTTY was heard in 1922. Without going into too much detail, other modes that we are beginning to think of as ancient are surprisingly new. PSK31 for example joined us in 1998, but Hellschreiber, is from the 1920's, MFSK comes from 1962 and Packet Radio hails from the 1970's. JT65 comes from 2003 and JT9 is from 2012. My point is that whatever the mode you're using, someone is extending it, modifying it, improving it or inventing something new. Your level of familiarity with a mode has little or nothing to do with the age of the mode. As is the case with everything in Amateur Radio, horses for courses. In your Amateur pursuits you'll come across those who will tell you that there is nothing new to be invented, that everything has already been thought of and that we are a hobby of old people harking back to the golden era of something or other. I'm here to tell you that nothing is further from the truth. Amateur Radio is a hobby of invention of people asking the question: "I wonder what happens if I do this...", often followed by a big bang and the magic smoke coming out. Don't let that deter you. Keep on with the experimentation, even if you've only been a member of this community for a minute and a half like me, you too can make a contribution. I'm Onno VK6FLAB

Alternating Current and Direct Current are the same thing ...

Jul 10, 2016 292


Foundations of Amateur Radio When you use your trusty multi-meter to measure resistance across a 50 Ohm resistor, it shows 50 Ohm, but when you use it across a piece of 50 Ohm coax, you see either infinity, or 0. Similarly, when you measure across a folded-dipole, you see 0, not 300 Ohm. Does this mean that a 50 Ohm resistor is somehow different than a 50 Ohm piece of coax and why is the feed-point impedance of a folded dipole 300 Ohm, when your multi-meter clearly says it's 0? Does this mean that there are two types of Ohm? Today I'm going to explain why this is and what's going on. Yesterday I started reading up on the subject and every single explanation I came across went into deep ju-ju with scary maths, using complex and imaginary numbers. I did a bit of that in my dark past, but none of that is needed to understand what's happening. As you know, there is such a thing as Direct Current or DC - we use it with batteries and little power supplies, in simple circuits and all manner of day-to-day activities. There is another world that we as amateurs use, the world of Alternating Current or AC. In house-hold wiring we use 50 or 60 Hertz and different voltages depending on where on the globe we are. In radio terms we use it for our transmissions, on HF at several Mega Hertz and beyond. These two different worlds, the DC and AC world don't appear to have anything in common. Here's the kicker though, they are the same thing. Yup. DC and AC are the same thing. What? Yup. I'm not making this up. As you might recall, if you look at an AC voltage, it goes from plus to minus and back again. A 50 Hertz alternating current does this swap 50 times per second. When you're rag-chewing on 40m, or 7 MHz, it happens 7 million times a second. From plus to minus and back, 7 million times. Clearly there has to be some impact on this massive level of activity. Think of direct current as an alternating current with a frequency of 0 Hertz, that is, over time, DC doesn't change. So, DC is a short cut for saying AC at 0 Hertz. If you understand that explanation, then some really cool stuff starts to happen. Before I get to the cool stuff, you might recall Ohm's Law, commonly expressed as: "Given a current and a resistance, we can determine a voltage". Said in another way, the resistance of a circuit is related to the voltage and the current in the circuit. Now, in this simple form of Ohm's Law, the voltage doesn't change from plus to minus and back again. That is, over time, there is no change. Now if you start doing funky stuff with your voltage, like change it from plus to minus and back again, an additional type of resistance comes into play, called reactance. This reactance is the part that is affected by voltage change over time. So if you swap the voltage from plus to minus and back again a million times a second, the reactance has a big part to play. In short, there are two types of resistance, one that is independent of time, called resistance, and one that's dependent on time, called reactance. Both of these, resistance and reactance, happen within a circuit. If the voltage doesn't change over time, then the reactance part is zero and similarly there are circumstances where you can have a resistance of zero but have a reactance that's not - one example is a folded dipole. Now, if you combine the resistance and reactance, you get something called impedance. Now you have all the bits. Resistance is expressed in Ohm, Impedance is expressed in Ohm, and thus Reactance is also expressed in Ohm. If we look at our folded dipole with a feed-point impedance of 300 Ohm, you now know that this 300 Ohm comes from a resistance of 0 Ohm and a reactance of 300 Ohm at the resonant frequency, which is why your trusty multi-meter shows it as 0, since the voltage it uses to measure is alternating at 0 Hertz, which is not the resonant frequency of this antenna. Before I go, the rabbit hole goes deeper. Reactance itself is made up of...

After the contest ... the debrief.

Jul 3, 2016 213


Foundations of Amateur Radio Today I'm concluding my breakdown of the contest that I participated in recently as a mobile station. I planned to make my contacts on one band and I did that. Feedback indicated that there were other contacts to be had on other bands, but switching bands is a non trivial affair with my current set-up. I planned to have a common frequency that would be a local cluster of activity, except it never happened that way because others decided to do their own thing. This meant that my antenna was tuned for the top end of the band, rather than the more typical centre of activity. I expected to work several home stations and managed to do so with two, but that was much lower than I expected and planned for, so my overall score didn't reach the planned levels, even if it was triple last year's effort. I planned to drive a circuit in about 90 minutes, instead it took about three hours. Fortunately there were lots of mobile stations about which helped me much more than expected. I keep telling myself that I need to sort out a voice-keyer because each time my voice gives out about half way through the contest, but again I keep forgetting to make that happen. My laptop power worked pretty well, but the location of the device, sitting on the passenger seat and then during on air activity, parked at the side of the road, it was balanced on my knee. Not ideal and not comfortable. My phone worked really well as my live GPS map and the boundaries I'd drawn using Google My Maps really helped to show me where I was in relation to the boundaries for this contest. I'm a relatively new arrival into the Amateur community but I often forget that I've been contesting almost from day one. My first on air experience was a club station during a field day camp out where the activity centred around a little folding table with Amateurs crowded around it. On air I have lots of broadcast experience, which means that I'm experienced in multi-tasking, coordinating frequencies, logs, callsigns, navigation and strategic objectives. I forget that this is not true for others on air. I love contesting, seriously, I love it. This activity puts me right on the bleeding edge of my capability and it's exhilarating to explore the peaks and troughs of the activity. I used rope to prevent my heavy antenna from breaking my boot lip mount and was worried about strange looks I might get. The rope worked well, the mount did not suffer from the experience and I didn't get much in the way of strange looks. In fact, much less than when I'm parked up with my 12m squid pole. Food and water worked great, but I will add public toilets to my map for next year, since it's not fun having to hunt. Mind you, a petrol station is a good option when you're in a hurry. At the end of the day, I managed to triple my score, I achieved all my objectives and proved to myself that my strategy, which came about thanks to discussion with fellow contesters, was solid, workable and a better performer than last year. I'm not yet sure how I'll change what I did, perhaps more antennas, parked at places longer, working more bands at the time might be an improvement. Time will tell. I hope that this adventure made you look at your activities and gives you some ideas on what to try, what to investigate and things to look out for. Hopefully I'll hear you on air during the next contest. I'm Onno VK6FLAB

How to make contacts during a contest?

Jun 26, 2016 280


Foundations of Amateur Radio Today I'm going to look at the actual on-air activity of the contest. Previously I've talked about the preparation and planning, as well as the doing, in terms of mechanics, what to bring, where to put it and how to power it all. At the most basic level, a contest is a combination of two things, making and taking calls. It's an important point, so I'll say it again. A contest is two things, sitting on a frequency and call CQ and have other stations call you, and, it's also hunting up and down the dial finding other stations who are calling CQ. These two sides, being the instigator of the contact, and being the responder, are needed to make points. Even the most advanced contest station with multiple operators and transmitters will do both these things and when you're on your own you too need to do this. One reason for this is that in a contest others are doing the exact same thing. They're also swapping between both these activities to pick up extra points and multipliers. Another reason is propagation. Your station is unique. It has a unique radiation pattern, a unique location, a unique audience of stations that can hear you at any one time. Across the duration of the contest this will change as day turns into night and night back into day. If you're mobile, there is an additional variable, your location which will affect your audience every time you move. If those two reasons were not enough, here's one more. How do you know if the band your on is working or not? How do you know if there are others nearby, or on a completely different part of the band, or, if the band is open or closed, or if solar conditions have shifted and a band has been affected? For my contest I had a vertical antenna mounted on my car. I can use it to operate on the bands I'm allowed to use, 10m, 15m, 40m and 80m. For this contest, my go-to band was 40m. Local conditions dictate that when dusk arrives, the lower part, 7.0 to 7.150 is all but unusable due to heavy interference from non-amateur stations overseas, so I picked a spot near 7.190 and used that as my calling frequency. Of course, as was expected, not everyone got the memo that I'd be up at that end of the band, and the little flag I posted saying that this was my frequency was dutifully ignored by everyone. What I'm saying is that there is no such thing as "my calling frequency", just the place where you like to call and you have to manage this along the duration of the contest, since others will find your little hidey-hole and use it at the drop of a hat. And if you're QRP like me, they might even just start calling CQ right over the top of you and you'll find that you think you're making contacts with stations that are not actually talking to you. In other words, be flexible. As a rule, for myself, having been bitten by this many times, I don't QSY to another band if a station I've just worked asks to do so, since the aim for your contest is for you to make contacts, not for someone else to make them. That's not to say that if it's 3 o'clock in the morning and nothing much is happening this won't change. Again, flexibility is key. I tend to use both VFO A and VFO B on my radio. It's a quick way to swap between frequencies or bands and it allows you to both sit on a frequency, calling CQ and hunt up and down the band at the same time. If that doesn't make sense to you, this is how I do this. I set my calling frequency up on VFO A and copy that to VFO B. I call CQ a few times on VFO A, swap to VFO B, scan up or down a little way, find a station that I'd like to work and swap back to VFO A, call CQ a few more times, swap back to VFO B, hear the station finish their call and hear them call CQ. I respond and if they hear me, I make the contact. If not, I swap back to VFO A, call CQ and do it all again. This way I can be in one place calling CQ and pick up contacts at the same time. If you have multiple radios, even as a single operator, you can do...

The logistics of being in a contest while mobile

Jun 19, 2016 202


Foundations of Amateur Radio Today I'm going to talk about the doing of a contest. Previously I discussed the preparation and you can go back to that and have a listen online, search iTunes for my callsign, VK6FLAB. The contest I participated in was a 24 hour contest. It started at 2pm local time on a Saturday and ran the whole 24 hours. If I was sitting in a shack, I might have and in the past actually have, operated during most of that. Seeing that this time around I was planning to be mobile, I needed to get sleep in between driving from location to location. In my car I have a suction cup stuck to the front windscreen which holds the head of my radio. It's mostly within reach, but if I operate for a little while, extending my arm gets tiring, so if that's the case, I drop the steering wheel, push it forward and modify my seat position. A better solution would be to find a better location, but I've not managed that yet. I keep looking at other set-ups, but haven't found one that works for me. I'll let you know if I do. My logging is done on a computer. A net-book. It's small, light and pretty responsive. It's running Windows XP, never connects to the 'net and it works. I balance it on my knee when entering contacts, or have it on the passenger seat and tap into it that way. Also not ideal. I saw a series of photos where a fellow traveller had used a plastic sewer pipe, and bend, to push into the cup-holder of the centre console and mount their computer on that. I've not yet travelled to the hardware store, but I can see a future where that might occur. Power for the laptop comes from a 12V power supply. It's plugged into the cigarette lighter, set to the voltage of my computer and plugged in. It has a handy USB socket on the power supply that I use to keep my phone charged. That sits on another suction cup on the dashboard in a mount. It showed me where I was and where the boundaries of operation where. Every now and then I even used it as a phone. Speaking about power. I power my radio with a 12V battery that's sitting in the boot. At night, finding the right keys to press is a challenge. The interior light of the car is one option, but I find it makes too much light, draws too much attention and uses more power than I'm willing to use. Instead I use an LED headlamp. I was wearing it for a while, but a better solution turned out to be attaching it to the sun visor where it still is. In terms of feeding and watering, for water I had about six bottles of water lying in the passenger seat foot-well. For food, a small insulated bag with fruit, apples, pears and a banana. I stayed away from nuts, sugar and other traditional stay-awake foods, because I find that I over eat, get sleepy and become less productive. In between locations I'd turn the radio volume down, turn on some classical music and let my mind relax a little. I drove about 300km during the 24 hours. Operated from 2pm until about 10pm and from about 5am to 2pm, a total of 17 hours. I managed to have a sausage roll for breakfast, not recommended, a few cups of coffee in the morning - keeping my eyes peeled for a coffee place at 5am paid off at 7am. I wore comfortable shoes, a t-shirt and jeans. Next time I'll wear shorts or tracksuit pants. The belt really didn't work for me for that extended period of time sitting in a car. Next time I'll talk about the operation during the contest. I'm Onno VK6FLAB

Training, Traumatic or Fun, you decide...

Jun 12, 2016 210


Foundations of Amateur Radio Training is a word that is steeped in tradition, it conjures up images of classrooms, teachers, chewing gum stuck to the bottom of your desk and being called upon to attend the front of the class to explain something based on the misapprehension that you did your homework. Fortunately this is a hobby and training is something you can do yourself, to yourself, by yourself at your own pace. Of course, you can choose to do it with others, but it's not required as such. We talk about being prepared for doing stuff, but what do we actually do to make that happen? I've said many times that I like to do contests. In fact, I'm preparing for one right now. This particular contest awards points for making a contact and doubles the points, a so-called multiplier, every time I work a different area. So, what does my training for this look like, what preparation have I done and what am I doing right now? My first step was to read the rules, the specifics of what is proscribed, what is permitted and what is counted and what isn't. This sets up the training ground, the framework under which I have to operate my station. My next step was to pull out a map and draw the boundaries of the areas that affected my score, showing those regions that I'd likely be in and likely make contact with. The crucial part for this was to see where the boundaries were, because it's likely that while driving around, having situational awareness will pay a good part of being successful. Then I looked at the band conditions. I set-up with my multi-band antenna, a multi-tap Outbacker, and set it up on the 4 HF bands that I'm allowed to operate on, 80m, 40m, 15m and 10m. I set out to make a single contact with each, based on another station a couple of kilometres up the road. We both have vertical antennas to increase our chance of success. Based on that I determined a few things. One, that this particular antenna and my car make for some pretty specific directionality on some bands. Two, that 10m and 15m were working close in, but not 20km away, that 80m sort of worked but that 40m was a winner. Based on this test I decided that 40m was going to be my frequency band for this contest. Then I went about getting tools together. I have a laptop for scoring and a power supply that connects to the car for the laptop. I've charged my radio battery, so it will run for a week on 5 Watts, got together pen and paper as a backup, found a USB charger for my phone and will shortly be packing fruit and water for while I'm on the road. Last night I fuelled up the car, ready for the contest, and this morning I dug out a few spare antennas in case one of my friends is able to come out and play on-air as well. I've looked at the map closely, did maths on how best to operate, added markers to my map where good operating positions might be found, likely they're completely rubbish, but going there is when I'll find that out. I've told others what I'm going to do, encouraged others to get on air and play and by the time I start I'll have had a healthy lunch, a hot shower and comfortable clothes to keep me on the road. I've packed a warm coat, and gone through the contest in my mind to see if I can think of other things that I might need. All this is only the pre-cursor to actually doing the contest. Call it Part 1. Part 2 is the contest and Part 3 is figuring out what worked and what didn't. I'll tell you about that next time we meet. Training, it can be fun, or it can be traumatic, you decide. I'm Onno VK6FLAB

How to get started ...

Jun 5, 2016 235


Foundations of Amateur Radio Today I'm going to talk about getting started. In the past I've mentioned that it's a good idea to find a community, a club or a local mentor to get you going in this hobby, and that still stands. You really need to find some like-minded, available humans to share this experience with. That being said, there are some things that you can do on your lonesome. An often asked question is: "What radio should I buy?" The answer to that question can be long and involved, but it boils down to this: "What ever you can afford." That answer in and of itself isn't that helpful. Do you get a $40 cheap hand-held or a $4000 all-singing and dancing radio? My best answer to that is: "Buy your second radio first." What I mean is that if you spend your money on a $40 radio today, how long will you enjoy it and how long will it be until you spend your next bit of money and is that $40 investment a waste of money? I'm not making a value judgement here, the answer is still: "What ever you can afford." When I asked that question of my mentor, Hi Meg, she explained that her first radio was a hand-held radio and that she quickly settled on a Yaesu FT857d as her second radio. She went on to say that picking a brand is like choosing between Mac or PC, Ford vs. General Motors, vi vs. emacs, Debian vs. Red Hat, Tomato vs. Tomato. There are followers in each camp and nay-sayers in every other camp. I picked my radio based on whom I had around me for support, who was nearby for silly questions, advice on accessories, experience with settings and knowledge of costs, faults and other intangibles that I was completely unfamiliar with. Once you get into this hobby, you'll come across people who have technical reasons for picking a particular radio, or sentimental reasons, or financial ones, or what ever reason they come up with. When you get started, not much of that matters. If you have money to burn, then sure, you can by the top-of-the range radio, but if you're never going to use it, what's the point? Once you've picked your radio, other choices follow. What power supply do I need, how much space do I need, what kinds of connectors does it come with, has it got a built-in antenna, or do you need to erect one, does it have a tuner built-in, or do you need to get one, do you need programming software, a microphone, etc. etc. Each of these follows from the initial selection of your radio. What now? You have a radio, presumably an antenna of some sort and your radio is actually turned on and you can hear stuff. If you've come from a short-wave listening background, you'll know where everything is, have a familiarity with the bands and an idea of how things work. If you're new to this hobby, then these things are not so obvious. Things to mention are that each band is unique, that is, they all have their own characteristics. Some are always noisy, others are always quiet, some are active during the day, others only at night, some have stations all day long and others only for short periods. A lot of this depends on things outside your control. Propagation is a variable animal and depending on what our Sun is doing, propagation will change, sometimes substantially, as time goes by. Forecasts for the weather are getting better. The same is true for propagation forecasts. A forecast is just that, a prediction of the environment, but not a guarantee of conditions. There is no substitute for turning on your radio and having a listen. If you're in someone else's shack, have a listen on their equipment, use the opportunity to learn something about different set-ups. If you get the chance, operate on that station and see what happens. Getting started isn't a magical invisible unattainable thing, it's taking the first step on your journey into this hobby of Amateur Radio. Get to it already. I'm Onno VK6FLAB

A surprise might be just around the corner...

May 29, 2016 201


Foundations of Amateur Radio This crazy hobby keeps sending curve balls to me. You've heard me talk in the past about missed opportunities. There are times when you look back and ask yourself: "What was I thinking?" Over the past, oh boy, I just looked it up, two years, I have been struggling with an antenna system that I could use while mobile. I took delivery of 4 single band antennas, one for 80m, one for 40m, 15m and one for 10m. I also purchased a boot-lip mount and some other things like coax switches and adapters. I've been attempting to make these antennas work with very, very limited success. They work just fine, they tune up as expected, show the SWR curve that the manufacturer has helpfully printed on a little card that comes with each antenna and generally are sturdy, compact and wonderful, but only if they're installed on something other than my car. In desperation a year ago I purchased a tuner for my radio, so at least I can trick it into transmitting. I have made very few contacts, added one or two DX countries in the past year and really got no-where. So, during the week I recalled that one of the things I purchased was an adapter. It's got a PL-259 socket on one end and a CB-thread on the other. I dug it out, found the thread that goes into the hole and attempted to attach it to the CB antenna I was given within a month of becoming an Amateur. It had been modified to work on 10m and most of my DX contacts had been with that antenna. So, I attempted to attach the adapter and it doesn't fit. So I look around my shed and notice another antenna that I was given at the same time that never worked, it's a multi-tap antenna. Picture an antenna that is a big stick, has wire would around its entire length with points where you can attach a lead to bypass some of the antenna. You plug the lead into the bottom connector, then pick the band you want to work on, put the other end of the lead into the right tapping point and off you go. It came with a big spring mount, was intended to be bolted to a bull-bar, but using a family sedan, makes attaching this contraption pretty hopeless. It'd tested it where I could, measured it, tested more, made a new wander lead with a solid connector and nothing I did made it work. It turns out that the thread in my adapter fits properly into the base of this multi-tap antenna. I took it out into a local park, put the antenna with the lead on 40m, bolted it to my boot-lip mount, halfway pulled out the tuning end, a little metal spike that you can use to adjust the length of the antenna and turned on my radio. Guess what happened next? Nothing, that's what happened. I was stunned, into silence, imagine that, me silent. It worked. No adjustments, no trimming, no fixes, nothing. Just plugged it in and it worked. Propagation was pretty poor, so no contacts as such, but oh my. The point of all this is that when you least expect it, a surprise might come your way. Look at the assumptions you've made in your shack, think of the things you've tried and failed to achieve and use that to take a fresh look at what you have. Hopefully your delight will be just as surprising as mine was. I'll be back on air a lot more, who know's I might even get the opportunity to have a chat with you. I'm Onno VK6FLAB

Harmonics and calling CQ

May 22, 2016 187


Foundations of Amateur Radio Have you ever had your radio on, listening around, say on 40m and heard the following: "CQ, CQ 40m, this is VK6FLAB, calling CQ 40, CQ 40m, calling CQ" Apart from the fact that the station calling seems pretty desperate for a contact, you're tuned to 40m, why on earth would you actually mention that, what's the point of telling me what band you're calling on, when clearly I'm hearing you on that band? The answer to this question is in harmonics. At the heart of every radio is an oscillator, set to some or other frequency that forms the basis of all that happens around it. In order to arrive at different frequencies, we add and subtract, double and halve frequencies, all combining to arrive at the various frequencies and bands we use. I'll use some fictitious numbers here to give you an idea of what's happening. Imagine that you have a 3.5 MHz oscillator. With it you can double it to 7 MHz, double that to 14 MHz, double it again to 28 MHz, that's 80m, 40m, 20m and 10m, just by using doubling. You could use the same oscillator and a doubler with a frequency tripler to get 21 MHz and so on. A side-effect of doubling and tripling frequencies is that this process isn't perfect or linear. This in turn means that some of those imperfections also get doubled and tripled. These imperfections are called spurious emissions and we reduce them as much as possible; in fact it's required by legislation to be below a certain level below the wanted emission. As technology improves, these spurious emission standards evolve. The US FCC as an example says that for radios built before January 1, 1978 they're exempt, radios until 2003 must be 30 dB below the wanted emission and current radios must be 43 dB below. What this means is that in effect your radio is transmitting on multiple frequencies at the same time, but filtering prevents most of this from coming out. Now, imagine that you have a series of dipoles connected to your radio, one for 160m, one for 80m, one for 40m, one for 10m, etc. Imagine that your radio was built before January 1, 1978 and you're calling CQ. The harmonics are being generated, and because you've got an antenna connected that can transmit those harmonics, they go out into the wide blue world outside. It's entirely possible that someone listening on 20m, 15m or 10m is hearing you calling on 40m through your spurious emissions at some or other harmonic. So, next time you hear a station calling CQ 40m, they're either rusted on die-hard amateurs on a modern radio, or they are using a so-called boat anchor, having fun on air. Either way, it's a great idea to say hello while you have the opportunity. Perhaps even use the experience as an excuse to learn more about their station, or even check out their harmonics and let them know if you can hear them. Propagation be damned. I'm Onno VK6FLAB

Lower and Upper Side Band, why is it so?

May 15, 2016 203


Foundations of Amateur Radio Today we enjoy radio using all manner of different so-called modes. The ones that most people are familiar with are FM and AM. In fact digital radio DAB+ is another example of a mode. In Amateur Radio we have a few more to play with, Single Side Band, or SSB, countless other digital modes, CW, or Carrier Wave are all different approaches to getting information from one place to another. If you have a radio that uses SSB, you'll soon notice that there are two versions of SSB, something called LSB and something called USB, or Lower and Upper Side band. If you tune around the bands you'll soon notice that some stations are using Lower Side Band and others are using Upper Side Band and there seems to be no rhyme or reason to it. Actually, there is a method to the madness. First of all, commercial and military HF radio all use Upper Side Band all the time. Radio Amateurs are a bit more traditional and we have the following basic convention. For voice signals on frequencies lower than 10 MHz, we use Lower Side Band, and for signals above 10 MHz we use Upper Side Band. There are exceptions to this. RTTY, one of the digital modes uses Lower Side Band regardless of frequency and all the other digital modes use Upper Side Band. Confused yet? Here's another way to think of it. Everyone uses Upper Side Band, except for RTTY and Voice below 10 MHz on Amateur Radio. Why are we doing this cookey thing to ourselves in Amateur Radio? First thing to note is that it's not random, we didn't just wake up one morning with this idea and said, lets do that. Side Band was first figured out mathematically in 1914. A year later it was made into reality by John Carson who used it to carry more long distance telephone calls across the AT&T phone system. There were on-air experiments and in 1933 the ARRL board instructed the technical staff of QST magazine to investigate the feasibility of single side band carrier-less phone transmission on amateur frequencies. There is lots to read about this in the January 2003 edition of QST magazine, if you're interested, it's a fascinating read. From an engineering perspective, radios built during the birth of Side Band, or Single Side Band Suppressed Carrier, to give its full name, used different methods to create a side band signal. One method was to filter out the part of the side band you didn't want, the other was to use phasing to add or subtract two signals and create a side band signal. Creating a filter was hard, creating a phase difference was much simpler to achieve. Now, one of the effects of using this method of making a side band signal was that you had a place where the signals would add and another where they would subtract. Where was this place you ask? One guess. 10 MHz anyone? So, for these radios built during the birth of side band, Upper and Lower Side Band came as a side-effect of creating a simple and reliable system to make the signal. Today we have alternatives which make this 10 MHz magic spot pretty much obsolete, but there are still 1951 Collins 75A-1 radios on air today and we like to talk to each other, so why fix something that isn't broken? That's why we use Upper and Lower Side Band. Remember, everything uses Upper Side Band, except RTTY and Amateur Radio phone below 10 MHz. I'm Onno VK6FLAB

Logging software ... what to choose?

May 8, 2016 296


Foundations of Amateur Radio Today I'm going to talk about housekeeping, that is, the things you should be doing while you're doing the things you like doing, like making noise on air. The topic of Logging is one that continues to attract comment, suggestion, frustration and on occasion ridicule. Let me start with the fact that the very first contact that I made was not logged. I can tell you exactly which day it was, Sunday, April 17. I can tell you where I was, Stirk Park in Kalamunda in Western Australia. I can tell you that the other station was a Japanese station, but that's all I can tell you. I don't know the time, the band, likely 10m or 15m, I couldn't tell you their callsign, even though I'm pretty sure that I wrote it on a random piece of paper at the time. It simply hadn't occurred to me that I should actually log that contact, or that I'd ever think back to that day and wonder whom I spoke with. So, if you've not yet been on-air, get your logging sorted out now. It doesn't have to be fancy, it can be your diary, a notebook, a binder, or a phone, tablet or computer with appropriate software, just actually start logging. Do it today. That out of the way, getting the entries stored somewhere, you'll soon notice that there are tools you love and tools you despise and that over time this changes. It also changes for different activities. If you're on the top of a summit or in a national park, you might just want a small notepad to log your contacts, but if you're in the middle of a contest you might just want to not have to worry about logging everything manually, you might just want to punch in the other station's callsign and their exchange. The point is that for every amateur activity there are different aspects of logging. If you're chasing island activations you'll need a spot for the IOTA number, but if you're actually on the island, others are chasing you, then a good contest log is likely all you'll need. So, I just said the magic word, good. What is a good log, what does it look like, which software should you look at? Well, as in everything in life, that depends. You're likely to change logging software across your amateur activities, either because you have come to dislike the one you're using, or because it no longer works on the current version of your computer, or any number of other reasons. When you're picking software, you should as the very first priority discard all logging software that does not allow you to export the log. If you cannot export, you're locked in and your data is very possibly lost at some point in the future, so only use logging software, if you're using software, that does an export. Now I did mention that you don't need to use software. Paper is perfectly fine, just a little harder to use if you want to check back and see when you worked a station more than once. It's also hard to use, actually, impossible to use, if you want to use Logbook Of The World, eQSL, clublog or any number of online contact verification tools. If you're looking to log during a contest, figure out if the contest is actually supported by the software, this will help you reduce the number of contacts you make that are invalid. For example, a contest might specify that you can only work a station every two hours. Relying on memory is not a good plan. Using a computer to do that is much more productive and reduces the number of contacts that are going to be tossed out by the contest manager - not to mention that some contests apply penalties if you log an invalid contact. A log that requires you to type in the frequency once is fine, but not if you need to type it in each time. If you're doing that on your phone, it'll get very tired very quickly. If your logging software won't work without an Internet connection and you're away from the net while being set-up as a portable station, you'll have all manner of issues, so consider that. So, what do I use? For most of my contest activity, at the...

What can you say on-air?

May 1, 2016 273


Foundations of Amateur Radio There are things to say and things not to say as a radio amateur. Let's start with swearing on-air. Each jurisdiction is different and changing. The Australian Radiocommunications License Conditions Determination, or LCD has nothing to say about content. It's all about bandwidth, frequency and modes. The rules in the USA discuss "obscene or indecent words or language", but there is no definition of what that might mean. A word in one country is meaningless, where in another it's completely unacceptable. Our station signals travel around the globe, so it's prudent to moderate your language and to refrain from creating a situation where offence might occur. Of course, there are those who take this to the n'th degree. There is a perception that you cannot use the words K-Mart or Target on air, instead referring to these locations by some euphemism. There is nothing in the rules saying that you are prohibited from stating that you purchased a tube of SWR grease for $1.49 from Target, but if you're using the bands to tell your fellow amateurs that you're offering a two-for-one deal on your pork chops because you're a butcher during the day, that's considered an advertisement and is prohibited. There is no prohibition on language about sex, religion or politics, but that doesn't make them good topics of general conversation. That doesn't mean that you are not allowed to discuss them on-air with a mate, it means that you should really think about it if you're raising this as a topic in a net. Keep remembering that there are people from all walks of life, across the globe, who can hear you. There is a funny clause in the Australian LCD, and I wouldn't be surprised to learn that it also exists in some form in other jurisdictions. Here, it states that the licensee must not transmit any form of entertainment. In Australia this is explained as not permitting music, but that is not actually a word that occurs in the conditions. It does occur in the USA and no doubt there are variations within other jurisdictions. This "entertainment" clause is about broadcasting. There is an attempt to distinguish between commercial on-air use, that of a broadcaster, and amateur use, that of a licensed amateur. The way it's worded in Australia is funny though. Am I entertaining you right now? Are you listening to this on-air? Am I currently in breach of the Australian licence conditions, or is the station that is transmitting my voice? To put your mind at ease, this is covered under another section, the licensee must use an amateur station solely for the purpose of transmitting news and information services related to the operation of amateur stations. The two clauses that I just mentioned, the entertainment one and the news and information one, are all part of the same section, so you need to read the whole bit to understand what's going on. Of course that won't stop complaints or other interpretations, but so-far, that's all we have. While we're on the point of describing what's proscribed and what's not. The Australian conditions say nothing about how to sign if you're operating portable. There is no rule that says that you have to. There is a document called "Amateur operating procedures" that states that the "information, about the operating procedures for the amateur service, can help prospective amateur operators studying for amateur exams". It suggests that you use the locality when you're saying your callsign and if you're using CW, it suggests a stroke and a number. This is why we have this proliferation of different ways of communicating this information. Stroke mobile, Stroke portable, Stroke QRP, Stroke VK6 they're all made up. None of them have any official status. Your callsign is just that, your callsign. That's not to say that it's not helpful to add that you're portable, mobile, on a bicycle or standing in the ocean, but it's not part of your station identification. There used to be a special...

QRP - When you care to send the very least!

Apr 24, 2016 222


Foundations of Amateur Radio Today I'm going to talk about QRP, a term that's used in various different environments and one that I've used in the past. So, let's start at the beginning. QRP is a three letter code, part of the so-called Q-codes, that can either be a question or an answer. It's used in Morse communications to either ask "Shall I decrease transmitter power?" or to answer "Yes, decrease your transmitter power." It was perfectly valid for a kilowatt station to ask: "QRP?" and for another kilowatt station to answer: "QRP". Language changes over time, meanings get inverted, changed, adopted and transformed. The three letter combination, Q-R-P, is no different. Today in Amateur Radio, the three letters are more like a word, rather than a code and the meaning has changed to indicate that a station is running low power or as an indication to others that they're likely to be a weaker signal that requires a little more effort to pull out of the noise than any other station. As you might know, propagation is a fickle friend. There are days when you cannot talk to the station up the road and other days when you can hear a low power station clear across the globe and everything in between. The assumption that a QRP station is always hard to hear is not set in stone and often is quite incorrect. That's not to say that people think it's low, they hear QRP and think: "Hard work". It's a bit like fishing for trout. Some days are good, other days are just wet. Another aspect of the concept of QRP is the amount of power. The definitions differ. There are some that say that any station using 10 Watts or less is considered QRP. Others set the bar differently at 5 Watts. The ARRL defines it at 10 Watts or less for SSB and 5 Watts or less for CW or Digital. The WIA website uses a generic 5 Watts on their Low Power Radio page and different contests have different definitions of QRP. It's clear that there is no single definition of what constitutes QRP, just that it's low power. For me, I use 5 Watts and call myself a QRP station. Should you tell the other station that you're QRP? Should you include /QRP in your callsign and say something like, this is VK6FLAB/QRP. It depends. There are times when my statement of QRP got me through a pile-up and other times when some smart calling didn't require me to mention that I was only using 5 Watts. I've noted in exchanges that I'm using 5 Watts and had positive responses. There was a time when I signed specifically with VK6FLAB/QRP, but it causes all manner of grief with confirmation of your contact, since some stations will log the /QRP and others won't, since it's not an official callsign suffix. So, QRP is a wonderful aspect of our hobby, it teaches you to learn about propagation, to get your antennas sorted out, to pick your times and to learn better operating procedures. I find it immensely satisfying to make a contact with my 5 Watts and there are times I wished my radio would go even lower than 5 Watts. I know of amateurs who have worked across the globe, that is, the opposite side of the world, the furthest they can get with just a milliwatt SSB, so I know that while my contact from VK6 Western Australia to CO, Cuba with 5 Watts was proof that it all works, I know that there is more to explore. QRP - When you care to send the very least! I'm Onno VK6FLAB

Coax impedence, 50 Ohm and 75 Ohm, why is it so?

Apr 17, 2016 270


Foundations of Amateur Radio There is a recurring question that never seems to get a straight answer. Why are we using 50 Ohm impedance and not 75 Ohm? The more people you ask, the more answers you get. There'll be commentary about standing waves, SWR, loss, incompatibility, soldering, cost, velocity factor, diameter, susceptibility to noise and the list goes on and grows, the more people you ask, the longer the list. Of course as time goes by, people remember stories told to them, guess, or even, how to say this, make stuff up. To steal a phrase: "Why is it so?" In the 1930's, when most of us were not even the apple in the eye of their parents - let alone their grand parents - coaxial cable was being developed for kilowatt radio transmitters. There are two aspects to consider, the amount of loss against length and the ability of the coax to handle power. Without going into the maths, there's plenty of that online, the lowest loss for air-dielectric cable is 77 Ohms. If we look at the peak power handling, that occurs at 30 Ohms, that is, at 77 Ohms, coax is best at getting signal across the cable with the lowest amount of loss and at 30 Ohms, coax is best at dealing with high power. Clearly a compromise is needed. So, the mean between 77 Ohm and 30 Ohm is 53.5 Ohm and the geometric mean is 48 Ohm, so, 50 Ohm is a compromise between power handling and signal loss, for air dielectric. So, obviously, 75 Ohm is used for TV reception and not for transmission. Except it ain't so. In 1938, Roy Plunkett invented PTFE or Teflon. This material wasn't around when 50 Ohm was decided on. If you remember, coax consists of a few parts, the centre and the shield, each conductors that we use to move our signal around and something in between, the dielectric, which stops the two conductors touching, with a cover over the top of that for good measure to protect against shorting and damage. The dielectric can be an air gap, or some form of plastic like PTFE. Electrically, the dielectric constant for Air is 1, for foam PTFE it's 1.43 and for solid PTFE it's 2.2. Turns out that this makes quite the difference. Our lowest loss coax, is 77 Ohm for coax with an air dielectric, but drops to 64 Ohms with foam and 52 Ohm with solid PTFE. So, rather serendipitously, 50 Ohm was a grand choice, good power handling capability and low loss with a solid PTFE core. Now, why are we using 75 Ohm for TV? One suggestion is that it's another compromise between low loss and cable flexibility. What does all this mean for you? In a nut-shell, 75 Ohm coax is one type of compromise, 50 Ohm coax is another. You can use either, but they won't be the same and won't react the same. Calculations made for one, will not apply to the other and loss and power handling will be different. This means that your roll of cheap Quad Shield RG6 is perfectly fine for some aspects of our hobby and not for others. Here's an interesting tid-bit to tide you over until next we meet. If we compare RG58, common in Amateur Radio to RG6, common in TV, the losses are quite different. For 100m of coax, at different frequencies, these start to add up. At 1 MHz, the difference in loss is .6 of a dB, at 10 MHz, it's 2.2 dB and at 145 MHz, it's 10.7 dB. To be clear, the loss for RG6 is lower across the board. This really means that you shouldn't be afraid to experiment. There is nothing particularly special about the different types of coax and each choice has it's advantages and dis-advantages. I'm Onno VK6FLAB

Q-codes in voice

Apr 10, 2016 232


Foundations of Amateur Radio This week I'm going to have a look at something called a Q-code. Last week I talked about a few aspects of operating. One of the inventions associated with human speech is the short-cut, a way to quickly say something rather than use the whole story. Before Amateur Radio this started on the telegraph with shortcuts called Q-codes. Think a three letter combination, starting with Q, followed by two letters. QTH, QSL, QRZ, QLF are examples. Language, just like Amateur Radio is an evolving feast. You'll find people writing articles about the abuse of Q-codes in speech going back to the early days of voice operation. The Q-code started with Morse Code as a way to quickly say something without needing to key the whole thing. This has flowed over into voice. You'll hear people use Morse-Code-isms in day to day language, 73, QSL, QTH and others are all examples of shortcuts that have no actual place in speech, but none the less have taken hold. Having said that, of course there is difference of opinion how you should conduct yourself. I know that there are things I hear on air that make me wince, and I'm sure that I've said things that make others shake their head. So, here's my take on how it should be done and feel free to do the same, or ignore me altogether. There is no such thing as "QRZ the frequency?". Nobody is calling the frequency. QRZ is specifically for the purpose of asking: "Who is calling me?" I know that there are some who are sharpening their pitchforks about now with all manner of comment, so let me be clear. I know, there are people who use QRZ in a pile-up. They've been calling CQ, had lots of replies, work a station and then after the contact say: QRZ?, with the meaning: "I'm done with the contact and I'm ready for another." This in my opinion is particularly poor operating, since it means that you're too lazy to say your callsign, disrespectful of all the stations calling you, arrogant enough to assume that everyone knows which station you are and oblivious to the notion that propagation is ever changing with new stations dropping in and out all the time. Instead of saying QRZ after such a contact, you're much better off saying your callsign instead. If you're in doubt, listen to some actually experienced contesters or DX operators and then you can you can fire off your feedback. I've been told that I have a habit of overusing QSL, but it means: "Transmission received and understood." and in communications there cannot be too much of that. I use it in day to day on-air language, use it in email and SMS and when I'm proficient in Morse, no doubt I'll use it there too. There are those that say that Hi-Hi, should not be used in voice, in Morse it's .... .. .... .., which sounds a little like someone laughing, which is where it comes from. Personally I think it's cute that you say Hi-Hi, even if someone who's not an Amateur doesn't share the joke. As a stick in the mud, I dislike 73's. If you're going to abuse a code, then at least use the correct one. It's nice in Morse, --... ...--, symmetric, the end of a contact, all fine. But there's not more than one of them and we're not sending off the number 3, seven times, so drop the 's'. I've been using language associated with broadcasting for a long time and I confess to wincing when I hear "Car-ah-be-an", rather than "Ca-rib-be-an", or "ad-ver-tise-ment" vs. "ad-ver-tis-ment" - no doubt some of my pronouncements will make you wince and some will find you agreeing. I'm Onno VK6FLAB

Operating Procedures

Apr 3, 2016 226


Foundations of Amateur Radio Today we're going to look at operating procedures, that is, what to say, when to say it and when not to say it. Amateur Radio being over a century old has lots of traditions and lots of quirky exceptions to rules, but you'll learn those as you go on air and make mistakes, and assume that you'll make those, probably regularly and every now and then someone will gently correct you, or you'll get shouted at, either way you'll get feedback. It's generally a better idea to figure out what's going on before you even open your mouth, so lets look at some things that really need to be second nature. Your callsign is always last. Always! That way the other station knows who you are, every time. I realise that you might not think that this is important, but just imagine that you've been inconsistent with this across your activities and one day you're in an emergency. Now it's crucial to know who is who. If you always do it the same, always your callsign last, then you'll do that in an emergency too. That out of the way, there are other aspects to operating that you need to take into account. You should always listen on the frequency that you're intending to operate. The longer the better. The reason I say that is because you may not hear both sides, or even two out of three, or more sides of the conversation. If there is a group talking, you may only hear one station who is happily chatting with others. After listening, you should say: "Is this frequency in use?" and listen some more. After about a minute, ask again, adding your callsign: "Is this frequency in use, VK6FLAB". If you still hear nothing, you can say: "Nothing heard" and start your transmission on the frequency. While you're operating remember that band conditions change and that you might find yourself all of a sudden among other stations that were not there earlier. They were, but you didn't hear them and you might actually find that they could hear you all along, so be prepared to make some new friends or make peace. There are idiots on air. You'll find net controllers who all of a sudden turn up on the frequency that you've been operating on and demand that you QSY. You can argue the point, or you can take the high road and leave the frequency to those who think they own the air. No mileage to be made from yelling at each other, no benefit and you'll end up looking like the problem, even though no single station owns any frequency. Similarly you'll find stations who have particular perspectives on how stations should operate and they'll go out of their way to tell you off. Pay no attention, unless they are actually going to make a formal complaint to your regulator, their feedback is just that, feedback. If you hear a couple of stations talking to each other and there's a few stations you know, you can drop your callsign in between the gap between overs and if they're inclined, a station will acknowledge you and let you in. This in turn implies a gap between overs. Sometimes that gap doesn't exist. If it's urgent, you can try your callsign and understand that it may clash with another station, but don't force it and if you're in a group, leave a gap after the previous station hands over to you. If you hear two stations discussing a medical issue, family affairs or other topics that are not generic, listen, but don't but in. When they're done and said goodbye, you can try your callsign and see if they respond, but don't expect it. Next week I'll take a look at Q-codes. I'm Onno VK6FLAB

Lucky Lightning Escape

Mar 27, 2016 171


Foundations of Amateur Radio In the past I've talked about our hobby and lightning. I've done it on more than one occasion, talked about cows and lightning strikes, about earth bonding and the dangers associated with lightning that's not directly overhead, but close enough to matter. On the weekend I learned the difference between saying something and seeing something. A group of Amateurs, went out camping, about two hours from anywhere in the middle of the bush to participate in an annual field day. We'd set-up our various overnight shelters, erected two marquees and proceeded to construct our portable shack. We were there for two nights. On the first night, the heavens opened up and the rain poured down, soaking the ground good and proper. We were lucky, our camp was at the top of a hill and drainage was great. At one point in the middle of the night I was standing outside in the rain, getting wet while attending to some ablutions - an unforgettable experience, but I digress. The next day the camp was in full swing. We were on air and operating, making contacts, despite the poor levels of propagation. We'd erected an 80m dipole, 40m of wire in the air, a 2m vertical, a G5RV antenna and some other wire antennas. Each of these had a piece of coax coming into the marquee and strung along the roof made their way to the appropriate radio. At that point the sky turned grey and thunder was heard. It was still dry, no actual activity overhead, or even within anything that could be considered nearby. As a precaution we disconnected our coax and settled down to wait for the impending storm. It never came. Other amateurs and house-holders were not so lucky, experiencing flooding and damage that was described as epic. Meanwhile back at our portable shack, we decided that it would be smart to separate power and coax a little. We started by pulling back the coax and moving it back into the roof space of the marquee. At one point, one of our team had his hand on the metal marquee frame and pulled at the coax connector that was feeding the 80m dipole. The next moment a crack was heard, he jumped. He's experienced a significant discharge between his hand and the coax. Remember, it's not raining, there's a grey sky and thunder can be heard in the distance. Looking back, I still cannot believe that between us, five Amateurs with a combined experience level of about 90 years between us, moving coax around while there was lightning in the air. What were we thinking? We were very lucky last weekend. It could have been much, much worse. I'm Onno VK6FLAB

The CAT interface

Mar 20, 2016 266


Foundations of Amateur Radio Today's Amateur Radio is less like the valve or transistor based radio and more like a computer. So much so that most radios today have a mechanism to connect the radio to a computer. This mechanism is called a Computer Aided Tuning interface, or CAT interface. It's a mechanism that's used to allow two way control information to be shared between the radio and a computer. This interaction is a serial connection, generally something called RS232. This is a standard that was developed in 1962 and it specifies things like timing, voltages and other attributes. The electronics from that era don't look much like the ones of today and most of the challenges with getting this stuff to work is related directly to these differences. It should come as no surprise that each manufacturer has their own take on what this whole contraption looks like and most of this technology is not directly compatible across radios. So, let's imagine that you've got a radio and a computer and they're physically connected to each other using a CAT interface of some description. We then need to make sure that things like the speed of both ends is the same, that is, the BAUD rate is the same. Also we need to check that the number of bits, stop bits and parity are also correct. If this sounds a little like 1980's modem talk, you'd be correct. The radio is presenting itself to the computer as a serial device, just like a dial-up modem does. If you've not seen this, just think of it as if the numbers at both ends need to match. Often the radio will have a standard setting, which you should use as a starting point. Now, I'm going to skip over things like IRQs and port addresses, not because it's simple, but because it might work out of the box, or it might cause you to lose hair. If it's the latter, you're going to need to do some IT support and this is about radios and not about computers. I'm also going to gloss over the problem that most modern computers don't have an actual serial port any more, most have something called USB which requires an adapter and software for the adapter, another potential minefield to traverse. Now comes the bit where it all works, right? Nope. Not yet. Next you need to have software that knows how to talk to your radio. It may be programming software, specifically to configure your radio, or it may be generic logging software that reads what mode and frequency you're on and puts that in your log, or it may be something that knows how to correct the frequency of your radio to deal with the Doppler effect of an overflying satellite. In each case, you'll need to tell your software several things. The most basic one of those is the port number. That is, of all of the serial ports on your computer, which one is connected to your radio? Seeing that all Amateur Radio manufacturers agree on everything, all actual control codes and responses are the same across all radios. Oh wait, nope, that's not true. They're not even the same across the same brand, so you'll also need to tell your software which actual radio you're using, which is the perfect opportunity to learn that your shiny new radio doesn't yet exist within the software. So, when you start looking at the CAT interface, you now know that this is a thing that's going to require some homework and planning. To make digital modes work, you need an audio interface to go with the CAT interface, which a whole different set of fun and games, including ground loops, impedance matching, levels, feedback and distortion. Now, if you thought that you and I took a lovely walk through the deep arcane world of serial computer interfaces, wrap your head around this. When we use the current crop of software defined radios, we replicate all of this, both CAT and audio interfaces with virtual versions of cables, BAUD rates and port numbers. Suffice to say, I don't have words. I should add that all of what I've said is just so you get an idea that there is...

Bandplans and Edges

Mar 13, 2016 156


Foundations of Amateur Radio Today I'm going to talk about operating procedures. Before groan and tune out, stay with me for a moment, this is important for all amateurs, even you. We as amateurs have a range of bands allocated to us. These bands cover a whole chunk of spectrum that we in many cases share with other users. They might either share the same band with us, or the other way around, we with them. Our bands might be right next to theirs or overlap in some part. To make things more interesting, these bands are unfortunately not uniform across the world. For example, in Australia part of IARU Region 3, the 40m band runs from 7.0 to 7.3 MHz. In Region 2, it's the same, but in Region 1, it only covers 7.0 to 7.2 MHz. If you look at the 80m band it's worse: Region 1 uses 3.5 to 3.8 MHz, Region 2 uses 3.5 to 4 MHz, Region 3 uses 3.5 to 3.9 MHz, but in Australia we can only use 3.5 to 3.7 and 3.776 to 3.8 MHz and that last little bit, the DX window, only if you hold an Advanced License. This can have profound implications for your operation on air. If you hear a station, clearly an amateur, callsign, working a pile-up and doing everything right, you may not actually be allowed to work them, even if you're privileged on the band you're listening on. Things get tricky near the edges of the bands. If you're operating near an edge, you are not allowed to have your signal stray across the band edge, so if you're using an SSB signal, the frequency shown on your radio is not where the edge of your transmission is, the radio is showing where the carrier is, the side-band signal depending on the type, can be another 2.5 to 6 KHz up or down. So, that's simple right. If you're using a band that uses Lower Side Band, say 80m, you can slide on up to the upper band-edge and start operating right? Uhm. No. Couple of things. The other side of the side-band doesn't vanish, it's reduced. Depending on the quality of the radio, the reduction is better or worse. Using an amplifier makes this problem bigger. Some radios have good filters on both transmit and receive which changes the picture again. I've not even talked about spurious emissions, harmonics and other artefacts which muddle this picture even further. The take-away for this is to make sure you know where the band edges are for your station and to make sure that you know what the performance of your actual radio is and where it transmits. I'm Onno VK6FLAB

What's in a Repeater?

Mar 6, 2016 190


Foundations of Amateur Radio Today I'm going to talk about repeaters. These invisible services that sit on a particular frequency and do magic things to your signal. First of all, the best way to think of a repeater is to think of it as two radios. One is the receiver, the other the transmitter. The way it works is that the receiver hears your signal and sends that audio to the transmitter which sends it out over the air. For this to work, there need to be two frequencies in use, the one that you're transmitting on and the one that the repeater is transmitting on. From this simple idea, many different things flow. There is no rule that states that the receiver and the transmitter need to be in the same place, let alone on the same band; if they're on different bands, it's called a cross-band repeater. If the receiver and the transmitter are on the same band, the system needs to deal with the fact that a strong signal is being transmitted by the repeater right next to where the receiver is. If you're not careful, the transmitter will overwhelm or de-sense the receiver, making it harder to get your signal into the repeater. Several techniques are used, a contraption called a cavity filter is set-up to specifically let either the receive frequency through, or to block all frequencies except the transmit frequency. Some combine both of these techniques to make the repeater hear weak stations better. If the receiver and transmitter are on the same band, the difference between the two frequencies in use is called the offset. It varies per band. On 2 meters, the offset is normally 600 kHz, but it varies, on 70cm the offset is 5 MHz, but on 10m, the offset is 100 kHz. So different bands use different configurations and of course each of these is subject to local variation. There may be local interference on the standard offset, so it may be varied. There are some other things going on with repeaters. You can have a repeater that receives and transmits on the same frequency, it's called a parrot repeater and it sits there waiting for you to transmit, stores the incoming audio for a set period and then when you stop transmitting, it sends out the audio on the same frequency. This is useful to see how you sound on-air. Other techniques include adding computers to create IRLP, Echolink and AllStar Link. Essentially the receiver is connected to a computer which sends the audio across the Internet to another computer which in turn sends out the audio to another transmitter. After you stop transmitting, the chain is reversed and the other station can talk to you via a reverse path. There are also specialised repeaters that can listen in one mode, like FM and transmit in another, like AM, or SSB. This allows a 2m user to use HF from their FM hand-held radio. If all that's not enough, there are other things possible with repeaters. You can use a special tone to identify to the receiver that your signal is a valid audio signal. This is used in environments where noisy local signals often trigger the repeater, resulting in ongoing kerplunking of the transmitter. Next time you key up your local repeater, have a think about what's happening when you key-up your radio and say thanks to the owner of the repeater who spent time and effort, not to mention money, to make this invisible friend on the air work for you. I'm Onno VK6FLAB

Experimentation is about failure ...

Feb 28, 2016 193


Foundations of Amateur Radio There is an interesting phenomenon that I've begun to notice and now that I've seen it, it's hard to un-see. Think of it as the equivalent of the little dot in the top right corner of the screen that signifies the end of the reel to a movie projectionist. Once you've seen it, you can't miss it ever again. If you haven't, sorry, you will and now you'll carry that with you for the rest of your life. Across Amateur Radio, from Foundation and Standard through Advanced or Technician and General though Extra, there is this thing where people get together and ask each other how to get started. It's amazing to observe, grown adults every one of them, not daring to take the first step. It ranges from keying your microphone for the first time, through to making your first HF contact, through building an antenna, going portable, climbing a mountain, making contact with the International Space Station, doing a contest, building a radio or erecting a tower. It seems that collectively we've forgotten that this whole thing we do is about experimentation. We're so wrapped up in failure that more and more I see people wanting reassurance that what they're doing is right. Like they have to somehow be perfect the first time, be amazing, be accurate, eloquent, sturdy, brilliant or whatever is going on. I don't know how this started, but it's got to stop. If we extrapolate along this path we're going to end up as licensed automatons with no innovation, no spunk, no mistakes and no learning. Don't mistake me. You're not alone, there is prior learning to be had and community knowledge to be gleaned, but if you never fall flat on your face, how will you ever learn to get up? So, next time you're getting ready to do something, just start. Don't wait for validation, take failure in your stride and learn. Last week a friend and I went to scout a new location for a field day contest. We drove there, set up our station and proceeded to spend the day failing. We got RF into the radio, the computer was barely readable in the sun, I got sunburnt, we made two contacts and had a miserable time with short power leads, hard to use trees and to boot, it was hot. On the flip side, we trialled a new antenna design, learned that my clip on ferrite chokes don't and that we now had a list of things we'd learned and stuff we needed to bring when we came up for real. We didn't go up there to fail, we wanted to activate a rare WWFF Park, but instead we failed and learned other stuff. Think of this whole thing in a different way, frame it not as success or failure, but frame it as a way to learn something. Edison had this to say: "Negative results are just what I want. They're just as valuable to me as positive results. I can never find the thing that does the job best until I find the ones that don't." Learning to experiment and being an experimenter and having a license that says you're an experimenter is also about learning to fail. Don't be scared. It happens to all of us. The better you fail, the better you succeed. I'm Onno VK6FLAB

What is the best antenna?

Feb 21, 2016 265


Foundations of Amateur Radio The single largest topic of conversation in Amateur Radio is about Antennas. The discussion often starts with one amateur telling another amateur about some or other amazing antenna, followed by a heated discussion about the merits or pitfalls of that same antenna and why they would never ever consider using it and why it's a waste of money, or some other rationale. Let's take for example the discussion of Dipole versus Vertical. There are those who will tell you that they'd never ever use a Dipole and similarly those who'd say the same about a vertical. Assertions of suitability aside, let's have a look at what we're talking about, first of all. In rough terms, a dipole is an antenna that is generally suspended between two sky-hooks, its fed from the centre and has pretty much an omni-directional radiation pattern. That is, signals arrive and depart from this antenna, pretty much evenly in all directions. Now, before you get all excited. It's not exactly the case, since it's not an isotropic point source, which you might recall is a theoretical antenna that we can prove not to be physically possible, but a dipole is the next best thing. A vertical is an antenna, which is often supported from a pole of some description, has some form of radial ground-plane at the base and while it's also omni-directional, there are parts of the signal that don't arrive nearly as well and other parts of the signal that fare better. Often a statement when comparing a dipole to a vertical will be something like this: "A vertical is better for DX and a dipole is better for local contacts." Now, let's just investigate that for a moment. If you've ever seen the radiation pattern for a vertical, you might have seen that there is a particular angle at which there is gain when compared to other angles. What this means is that signal arriving and departing from the antenna in essence favour that angle. Similarly, a dipole doesn't display this phenomenon nearly as sharply. There is some asymmetry between the sides and the ends of a dipole, but it's not particularly strong. Not that it's non-existent, just not pronounced. If you were to overlap the radiation pattern of a dipole and that of a vertical, you'd notice that apart from the single angle where the vertical favours radiation, the dipole pretty much has the same level of gain all round. In essence, this means that to all intent and purpose, apart from a single little angle, the dipole is pretty much the same as a vertical. I hear you say, "Yes, but..." Indeed. Think of a vertical as an antenna that favours a particular angle of incidence. It's more prone to hear signals from that angle than any other angle. Similarly, any transmitted signal is likely to favour that particular angle. As you know, the ionosphere is a moving feast. Signals arriving at one angle one moment may not be arriving at the same angle the next moment. If your vertical hears a signal one moment and not another, does that make for an effective antenna? Another aspect that separates a vertical from a dipole is the behaviour of vertical signals, so called NVIS, or Near Vertical Incident Signals. Things that are nearby. A vertical antenna all but ignores that aspect, where a dipole has no such behaviour. So, we're getting to the heart of it, imagine for a moment that the differences between a vertical and a dipole is their difference in filtering of signals. That is, a vertical filters signals from above, where the dipole doesn't. Similarly, a vertical filters all but the bits from a particular angle of incidence, where a dipole doesn't. If you've followed along, you might begin to realise that there is not a single "best" antenna. It's horses for courses. Your antenna choice is based on what you aim to achieve, not which antenna is better than any other antenna. So, the question: "Which antenna is the best?" should really be: "Which antenna is the best for this particular activity?" ...

The humble dipole ... contraption.

Feb 14, 2016 337


Foundations of Amateur Radio Today I'm going to talk about dipoles. You know the tried and true antenna, the go-to design for getting on air, the simple first antenna you ever make, the one you learn from, you know the one. It's the mainstay of every amateur, of any field-day, of all things Amateur Radio. It's a simple thing. Using metric, rather than imperial measurements, but the point stands, you use the speed of light in vacuum divided by the required operating frequency and you get the overall wave length for that frequency. In absolute terms, roughly 300 m/s divided by 50 MHz, gives you 6 meters. Surprise, that's the band name for 50 MHz. Now the dipole is a half-wave contraption, so, 6 meters divided by 2 gives you 3 meters for your total half-wave dipole. Each leg is half that, a quarter wave length, so you have 3 meters divided by 2 again and you end up with two bits of wire, a meter and a half long each. If you're following along, that's 300 divided by 50 divided by 2 divided by 2, or using the same numbers in a slightly different order, 300 divided by 2 divided by 2 divided by 50 MHz, or 75 divided by 50 MHz. Still one and a half meters per leg of your shiny new dipole. So, the basic formula for a metric dipole can be stated as 75 divided by the frequency in MHz per leg. If you're playing with feet and inches, 300 m/s becomes 984 ft/s, half that is 492, half that is 246 feet, so the imperial version is 246 divided by the frequency in MHz, gives you length in feet for each leg. So, you've cut your wires, tied them to some magical feed point contraption, plug it into your radio and you're good to go, right? Now, anyone who's actually done this knows that this is not what will actually happen. It's never that simple, and frankly if it were, we wouldn't be Amateurs, we'd be, unlicensed or something. So, what affects the actual length of this magical antenna? Lots and lots of things. Here are a few that come to mind: - The thickness of the wire you're using. - The thickness of the insulation on the wire. - A thing called the end-effect. - The height of the contraption above the ground. - The kind of ground. - The price of the copper you're using. Sorry that last one isn't right. I have been told, time and time again that there are only two kinds of wire, cheap wire and free wire. The preference is for the latter. So, price of the copper doesn't matter. Another thing that does matter is that some wire can stretch while in the air, making the antenna longer, so keep that in mind. Fine and well I hear you say. But how does this really matter? If you increase the thickness of the wire, the resonant frequency goes down, that is, the antenna is "too long". If you increase the thickness of the insulation, the resonant frequency goes down as well. The end-effect is like adding a capacitor to the end of the wire, making it "longer" as well. The height effect is different for each height. Generally the effect is that the antenna resonates at a lower frequency. Each type of ground has a different amount of effect. Water vs rock vs sand vs clay. I can hear you groan at this point. First comment to make is that all of these effects make the antenna resonate at a lower frequency. This means that the suggestion to cut your antenna longer than the calculated number doesn't make much sense. If you start with the basic calculation, 75 divided by the frequency in MHz, you'll end up with an antenna that's extremely likely to be too long. I can hear you screaming at me right about now. Hold your tar and feathers. I gave you the First comment. Here's a Second one. If you don't have space for a straight dipole, say, you need to go around a corner, or put a bend in the wire, all of what I just said goes out the window. If you put this above a metal roof, poof, also out the window. If you cannot terminate the wire to a rope without bending the end of the wire, poof. A Third comment. You cannot cut wire longer. You can only...

Sizing your battery.

Feb 7, 2016 218


Foundations of Amateur Radio Today I want to raise the topic of batteries. Specifically, sizing the battery. You can do as I did naively, look at the manual, see that the current consumption of your radio is 22 Amp, decide that this means that you need to get a 26 Ah battery to use your radio for 1 hour. Being the portable type, I got two, 52 Ah in total. Some time has passed since I made that purchase. I've learned that I can get a lot more out of my battery than 2 hours. I also learned that lugging 56 Ah around is not fun. Having learned this, what could I have done to improve? Well, first of all, the 22 Amp is for Transmit. According to the manual, on receive it's only using 1 Amp. If you're not transmitting all the time, then you're not drawing 22 Amp the whole time. The ratio between send and receive is the Duty Cycle, often expressed as a percentage of the time spent transmitting. Another thing to note is that 22 Amp is when you use full power for a particular mode and band combination. On my radio that's 100 Watts, HF FM, so only using 5 Watts will reduce the power consumption radically. Speaking of which, my radio has different maximum power levels for different bands, so when you're doing the maths, you need to take that into account. If that didn't add enough complexity, different modes use different amounts of power. AM, FM, RTTY and other digital modes use 100% duty cycle. CW uses 40% and SSB only 20%. So, rough back of napkin calculation, using 5 Watts SSB on HF for an hour, transmitting only half the time gives you 22 Amps times 5% power, times 20% SSB, times 50% of the time, a 10th of an Amp. Now, before you go out and buy a 1 Amp Hour battery and expect to use it on HF for 10 hours, there are some wrinkles. First of all, a 12 Volt, 26 Amp Hour battery doesn't actually give you an Amp per hour for 26 hours at 12 Volt. It's graded on a scale. At the beginning it gives you a higher voltage, at the end it gives you a lower voltage and after a certain point you've actually destroyed your battery, not to mention that the radio stopped operating when the voltage went below 11.7 Volts - somewhere around 30% capacity. To make things even more interesting, different batteries react differently depending on how fast you're drawing from them. Another issue is that temperature affects how much power you are able to draw. After all that, the manual for your radio is specifying theoretical numbers, not actual ones. I've never ever seen my radio draw 22 Amps, even when it was running flat out. On the flip side, I've also never seen my radio draw less than 4 Amp when transmitting, so the maths for this doesn't add up as expected. So, why was I giving you the maths if it doesn't work out? Because the Simple Simon Says solution doesn't work, but neither does some educated calculation. I hear you saying: "Well, that wasn't helpful." Actually it was. Now I can tell you something and you'll know why it will help you. Get yourself a power supply with a display that shows Amps, or get yourself an ammeter and stick it into the power supply circuit and take some measurements. Use a dummy load as the antenna, since SWR will also affect these numbers, as does the microphone gain, the squelch level and the volume level, as well as the display on the radio, the tuner and other things you have connected. Theory is great, practice in this case gets you a lot more reliable result. I'm Onno VK6FLAB

Where did all the amateurs go?

Jan 31, 2016 230


Foundations of Amateur Radio There is a recurring topic in Amateur Radio circles, called "permissions", or "rights", or some other word indicating "entitlement". It's a conversation that has been happening since the dawn of radio experimentation and will continue until well after our Sun has burped it's final sun-spot. In Australia, there are three classes of License, in increasing level of responsibility they are Foundation, Standard and Advanced. There is an ongoing tension between these categories. Some higher level responsible licensees look down on the class with less responsibility, and the reverse is also true. This separation of class is an evolutionary one. As I said recently, the most recent overhaul, more than 10 years ago, back in 2005 saw the introduction of the Foundation Class and the consolidation of various classes into Standard and Advanced. There are current noises being made about how this needs to change. There are those who suggest that the Foundation Class needs to have access to more power, to more bands, to more modes and various other suggestions. There are recurring noises of making the Foundation Class require a renewal and other such things. Often there is some link made to the growth of the hobby. Make it simpler so we can get more people, make it bigger so we get more people, make it harder so we get better people, make it ... something else. I'm a computer geek. I like playing with data and I like to figure out how stuff works. Over a year ago I started the process of trying to understand how amateur radio ebbs and flows. For example, in rough terms, in the 10 years that the Foundation Class of license has existed, we've issued about 10,000 new licenses, so around 1,000 a year, give or take. In the same time, the total size of the amateur community has stayed pretty much the same. So, did we loose all those Foundation entrants, did the old ones die off, did something else happen? Is a licensee who starts and stays for a year more or less likely to upgrade? Is there a time window when the likelihood of dropping out is increased? Is there some underlying factor that causes people to leave the community? Is there a correlation between on-air activity and longevity in the hobby? What about age, gender, etc. We simply don't have the analysis at this time. I've been at the ACMA and the WIA to get access to historic data, frankly it's been a hard slog, the ACMA pointing at the WIA and the WIA claiming license restrictions and neither giving any indication that they're doing anything to resolve the issue. In case you're wondering, I'm talking about the public RADCOM, now called SPECTRA database, nothing secret or private about it. I recently hit on the idea of using contest logs from the various contests to determine actual on-air activity. So that will add several gigabytes of data to my investigation. And an interesting side note - based on incomplete data, the 2015 CQWW Phone Contest saw the submission of 60 logs from Australia, but around 750 actual stations from VK were heard on-air. I'm attempting to get the same raw information from the local contests. This will give me a "Last Heard on Air" date, which will give me an indication of the status of the callsign involved. So, regardless of where you stand on the notion of the amount of responsibility you have as a Licensed Amateur, it's clear to me that we need more information. I think this is important for the future of our hobby and I'm working on it. I'm Onno VK6FLAB

Reviewing the introduction of the Foundation License.

Jan 24, 2016 243


Foundations of Amateur Radio The history of the evolution of amateur licensing is a nebulous affair, told and re-told, moulded, changed and interpreted by the story tellers along the way. There is an on-going debate about how the restructure of the licensing regime in Australia, in 2005, has affected our hobby. In 2005, after a 10 month review period, three classes of license were established, a new Foundation class, an a re-imagined Standard and Advanced class, using existing novice and novice limited licenses to create the Standard class and combining limited, intermediate and unrestricted licenses into the Advanced class. I've touched on this subject before, back in 2011, when I noted that those who forget history are doomed to repeat it. The ACMA published the review in May of 2004. It summarises the responses about the introduction of the Foundation licensing option. It opens with, "Over two-thirds of submissions were in favour of the introduction". It goes on to say that the most common reason for support was the need to make the amateur service more accessible and cited that the Foundation class then introduced in the UK was the appropriate standard. The majority of respondents suggested that the maximum transmitter output should be 100 Watts PEP and suggested 80m, 40m, 15m, 10m, 6m, 2m and 70cm as the appropriate bands. Also of interest is that 39% of respondents were in favour of a two-tier licensing structure, where 24% were in favour of a three-tier structure. The ACMA report also mentions that many respondents suggested that the foundation license should not be renewed without the licensee being re-examined. If you're familiar with the restrictions and obligations of the Foundation License then you'll recognise that some of these responses were agreed to and some rejected. I've not included the full report, it goes to 15 pages, but there are some other interesting things in the ACMA report. The ACMA notes that the main reason cited for requiring a Foundation licensee to be re-examined was to promote the license as a "stepping stone" to amateur radio operation. It notes that while there are provisions in the Act for such a re-examination, where there are reasonable grounds to believe that a qualified operator would be unable to achieve satisfactory results. The ACMA notes that none of the current amateur licensing options requires an amateur operator to be re-examined regularly. I wonder if we actually forced all amateurs to re-do their license, how many would actually pass? I know I would. There are other interesting things afoot. There is discussion today about allowing Foundation Licensees to use digital modes, but there is a move to require that it be added to the syllabus before that is permitted. Of course there is a parallel to make, none of the current licensees have any such formal training, why should a Foundation Licensee be "special" and require extra training. I've been asked what I think about privileges and the Foundation License. To be clear, I'm perfectly happy with my privileges. I have yet to experience all that Amateur Radio offers, and by turning my operating power to half the permitted level, 5 Watts, I'm learning specifically what works and what doesn't. I'm learning about propagation, about antennas, about operating techniques and about patience. I'm sure that this stands me in good stead wherever I go. One final comment, the ACMA report references a submission by a group called CQVK. I managed to track down the 112 page submission and have uploaded it to the F-troop website, the home of the weekly net in which New and Returning Hams can get together every week. Have a look at the ACMA report and the CQVK report at http://ftroop.vk6.net. As I've said before, those who forget history are doomed to repeat it. Let's not. I'm Onno VK6FLAB

How to manage your first pile-up.

Jan 17, 2016 287


Foundations of Amateur Radio There are skills that come from thinking and there are skills that come from doing. There is place for both in Amateur Radio. There is nothing in the world that is like the experience of working a pile-up, unless the trading floor of the New York Stock Exchange counts, but I've not personally been there and it doesn't look as intimate as a radio shack. Working stations across the planet that are coming in thick and fast is an amazing thrill, not unlike getting onto a roller-coaster. The long slow journey to the top of the ride is calling CQ, the crest of the hill is the first response and the loop-de-loop is when they're all calling at the same time; rolling back down to earth at the end of the ride is the petering out of the calls, only to start again. If you've never experienced it, I'd strongly recommend that you find a way to put yourself in the position where you are exposed to this absolutely thrilling experience. So, what do you do when you're actually in this situation? Hopefully you're not going to be on your own the first time, but it does happen and it might be that the person you're with has never had the experience either, so here's some ideas on what to do. The first thing to remember, this is YOUR pile-up. You're the one running it, you're the one in control of it, it's your actions that make it work, or not. I've said in the past, it's all about rhythm. It's about expectation management. If the pile-up sees you floundering about, not being consistent, not giving out succinct information, they'll go elsewhere and the experience will be over before it begins. So. The noise is overwhelming, there are stations all over the place calling you. If you hear a callsign, or most of a callsign, then call that. Don't change your mind if someone else comes back instead. You've called CQ and let's say that you heard, K1R. You call back, K1R, 59. If the station operator on the other end is any good, the response might be HK1R, 59 also. Your response will be HK1R. CQ VK6FLAB. But lets say that you only heard K1. You call back, "the station with K1". The response is three stations at the same time, one SK1Q, one VK1AA, one JA7BG. You could get upset about the JA7 station calling, but remember, he too has lots of stations calling around him, he might not have properly heard either. You say "the station with K1, K1 only please". Two stations come back. SK1Q and VK1AA. You pick the one you hear best. SK1 again. You hear SK1Q. "SK1Q, 59." If your memory is great, you could also go on to say "VK1AA 59" and then call CQ. This is not something you'd do on your first or 10th pile-up, but it's something to work toward. The thing that took me a while to recognise is that there are idiots on the band who think that their callsign is the most important. My best advice is to ignore them. This is hard. They'll be very noisy. One trick, call while they're calling, rather than let their rhythm destroy yours. Remember, this is YOUR pile-up. Other things to note. I've spoken in the past about the so-called standard phonetic alphabet. As you might remember, there is no such thing. This will trip you up. Don't let it bother you. Other fun stuff that happens in a pile-up, especially if it's been going for a little while, is that you notice little comments. You might inject one of your own. "HK1R Big Signal, you're 59". Or if it's a friend, K9CT, you might say: "K9CT, Hi Craig, long time no see, 59." It's the little inserts in the middle of a pile-up, in the middle of the night that make you smile and give you that shot of adrenaline to make it last longer. I have to admit. For me, there is no stronger drug that riding a pile-up. Of course, this is not all there is to learn about pile-ups. It's to give you some idea of what's going on and what you might do to keep it alive when it happens to you. Feel free to get in touch with questions if you like. I'm Onno VK6FLAB This and other episodes are...

Have a look or search online at the previous editions of this podcast.

Jan 10, 2016 131


Foundations of Amateur Radio This is episode 236 or so of my weekly contribution to this hobby. As you may have heard me say over the past few weeks, this is now available as a podcast which you can subscribe to. It's available at http://podcasts.itmaze.com.au and you can also search for my callsign, VK6FLAB on iTunes and find it there. I'm mentioning this because each podcast also contains a transcript, which you can use to search the content. I've been doing this podcast since May 2011 and in that time I've covered many topics. I get wonderful feedback from you about each segment, thank you, and I also get requests for content. Often new listeners ask me if I could talk about XYZ topic, and I'm finding more and more that in fact I have talked about such a topic. That's not to say that I won't revisit a topic if I have information to add. For example, I was in the process of researching baluns, got distracted by word-use and will revisit. As I'm doing the research I'm realising that the rabbit hole goes deep on that particular topic, so I'm not yet at a point where I can say much about it other than to think of a balun as a maths tool for feed-point impedance, that is to say, a 6 to 1 balun will transform a 300 Ohm feed-point to a 50 Ohm one, similarly a 9 to 1 will do the same for a 450 Ohm feed-point. All fine and dandy, but why would you need a 1 to 1 balun. Or what's the difference between a voltage balun and a current balun, not to mention the bandwidth, the different material types, and on it goes. So, I'm not yet at the point where I can distil the information to a three minute segment, but I will. I've also discussed cows and lightning in the past. If you remember, if a cow is facing the impact point of lightning, they can die from the current that flows along their body from their front legs to their rear legs. Which is why you want a single point earth in your station. I hope that you'll take the opportunity to have a look-see across the previous editions of this segment and find something to your liking. I'm Onno VK6FLAB. This and previous editions can be found online at http://podcasts.itmaze.com.au/ and are also available for download from iTunes and other podcast directories. Just search for my callsign.

Contesting, something for everyone ...

Jan 3, 2016 217


Foundations of Amateur Radio Previously I've discussed different aspects of contesting in relation to Amateur Radio. If you're unfamiliar with the concept, contesting is an activity where you test your station and skill against other amateurs. Unlike other contests where you're all in the same physical location, say a stadium, or an online playing field, amateur radio contesting is most commonly done from the comfort of your own shack. Of course, as is true for everything in life, there are exceptions to this. There are contests where you're not in your own environment, say on a field day, at a contest station, or some other place, but I'll ignore these for the moment. In most organised sports, and amateur radio is no exception, there are rules for participating. It should go without saying that you're expected to abide by the rules. Disqualification, bans, even life-time exclusions and revision of results can and have happened. Contests are planned by different people and groups and vary greatly across the globe. Amateur Radio is a global pursuit, and contesting is a global activity. It can start as simple as making a contact every day, through to staying awake for 48 hours and making as many contacts as possible across as many countries as possible as fast as possible, and everything in between. If you think about that for a moment, you'll soon realise that with so many different people organising contests, there is likely going to be one that tickles your fancy. There are several contests every weekend and often one every day. People participate in contests for different reasons, to try their new station, to win, to get another country on their DX list, to achieve a distance record, to test their skill, to learn how to hear callsigns in noisy environments, to spend time on-air, to laugh with friends and to contribute to the hobby of amateur radio. If you're new to our community, then contesting might be a scary proposition. You might not know what to do, or how to even start. You should know that your doubts were true for everyone you hear on air. We still haven't mastered the art of growing an amateur in utero, though I should confess that some act as if they are. So where do you start? The best way to do this is to set-up your station and to tune around the bands and to listen to what is going on. It will be confusing at first, but if you find a station that is making contacts that are different from normal ones, you know the one where you both exchange callsigns and a signal report, you'll begin to hear other parts of the contact. It's possible that the station is exchanging a serial number, or some other special token. You can also go online and find many different amateur contest calendars which each will give you a way to find out what global activity is currently taking place, so you can look up the contest online and read the rules. If all that's too hard, talk to your fellow amateur friends and go to their station and see what they do to participate in a contest. I'm Onno VK6FLAB This and other episodes of Foundations of Amateur Radio can be heard via podcast or download at podcasts.itmaze.com.au.

SDR diversity and Ah-Ha!

Dec 27, 2015 222


Foundations of Amateur Radio In every new technology there is an ah-ha moment, the single one insight that defines for you personally what this technology is all about. No doubt this happened when Amateurs first used valves, when they started using transistors and so on. For me that moment happened during the week. You've heard me talk about the absurd noise floor, that is, the incredible amount of local radio noise that I experience at my shack. I've been working my station portable to get away from the racket. During the week I came across something that is likely to change that. You've no doubt heard about diversity reception. You can use two different antennas, do some fancy phase switching and make the noise go away. Now I should clarify, at least briefly what that looks like. Imagine throwing a stone into a lake, it makes waves. If you throw two stones into the lake at the same time, the waves get bigger, but if you were to time it just right, you could throw in one stone, then the next. If you timed it just so the first stone would make a wave top whilst the other stone made a wave trough, the two would cancel each other out. You can do the same with light, shine a torch onto a piece of cardboard with two slits cut into it. Behind the cardboard you'll see light and dark patches where the frequencies line up and cancel each other out. Light and radio waves are part of the same spectrum, so you can do the same with radio waves. You could use this technique to cancel out, or rather filter, local noise. So far I've not said anything particular worthy of ah-ha, but stick around. There are devices made that you can use to create the equivalent of two slits, by changing inductance and capacitance within a specific circuit, you can align two signals from two antennas and make them cancel each other out. The way that works best is if one of the antennas is really good at hearing noise and the other is responsible for hearing the required station. You can then mix the two signals, I don't have such a device, but I'm told there is an art to making this work, and out pops the station you care about. In software defined radio or SDR, you can do this exact same thing. Only you don't need a circuit to do it, you can show the results in real-time and you can create a user interface that makes it really easy to try different things. The example I saw is PowerSDR, an open source project that allows you to control many different radios. Picture a circle with a line that is attached to the centre of the circle and the end is attached to your mouse pointer. You can move the mouse anywhere in the circle and as you do this, you're controlling two parameters, the phasing angle and the gain. The gain is the length of the line, the angle is the direction in which the line is pointed. While you're moving your mouse about, the signals from both antennas are mixed together according to the position of the mouse at the time. The end result is a completely interactive direct feedback loop where you can see and hear the effect of the mouse location. You can move it around very simply, and immediately, continuously see the result. The outcome of all this is that you can bring your noise floor down by 30dB or more, and hear stations that were completely inaudible within the racket. I'd heard it being described, but seeing it in action was a show stopping moment for me and right there and then I knew that the landscape in radio has changed forever. I'm Onno VK6FLAB This and other episodes of Foundations of Amateur Radio can be heard via podcast or download at podcasts.itmaze.com.au.

We should stop requiring electronics to be amateurs.

Dec 20, 2015 242


Foundations of Amateur Radio On a regular basis I receive emails from fellow amateurs and shortwave listeners who provide feedback and ideas about this weekly segment of Amateur Radio. It's a joy to read how they feel that my little contribution encourages them to continue in the hobby, or come back to the hobby, or to build something, or to do something, to participate, to experiment. Yesterday I received an email from an amateur who came up with an idea that's worth sharing. The idea was pretty simple. Encourage every new entrant into our hobby to build a crystal radio. I know that this might sound like a trivial thing, even silly, but for me it makes complete sense. Imagine that, building a receiver and understanding how it actually works. I know I've never actually done that and I suspect I'm not alone. So, here's a thing. Next time you're looking for a project to do, for a thing to make, for some soldering practice, try making a crystal radio. There's opportunity to make it work for CW and SSB - think of it as an upgrade - and from an electronics perspective, this can be as complex or simple as you like. Dovetail that with the notion of harmonics, how resonant circuits work and you're well on the way to making your first transceiver. So, the real takeaway from this idea, not only the idea you can build a crystal radio, but that there are electronics project to be found that enhance your understanding of how radio works and are easy to build. Now I should hasten to add, that I'm not advocating that we all become electronics experts. I know this isn't going to sit well with everyone, but let me say it again. I'm not advocating that we all become electronics experts. I know that the Standard and Advanced licenses in Australia require a fair bit of electronics, but I have to say that I think this is unhelpful. It's taken me a long time to get to this point, so before you sharpen your pitchfork and heat up the tar and feathers, hear me out. In Computing, which is a topic I know a lot about, having been intimate with it for nearly 45 years, there's a similar analogy. The notion that you need to know about memory, registers, about CPU clock cycles and a stack, accumulator and all manner of esoteric detail. I know all of this because 45 years ago, that defined what computing consists of. It stands me in good stead today, it makes it possible for me to conceptualise a super computer with little effort, but it's not required for someone coming into the field, learning to program and make the tools useful. It helps, but it's not required. We abstract things more and more in computing and we do the same in amateur radio. If you think back, a spark-gap transmitter, valve based radios, transistor based radios, integrated circuit based radios and now software defined radios went through the same progression. Today an amateur doesn't learn how to build a spark-gap transmitter, though if you did, it would help your understanding of high-voltage electronics, harmonics and all manner of flow on. It's not required. A similar thing is true for building a valve based radio and over time the same will be true for transistors, integrated circuits and software. You might think of this as a dumbing down, and to be fair, I thought the same thing for many years. In reality, it's not dumbing down at all, it's focusing on what's important, on what makes progress, on what grows a field. There will be always room for people who understand the difference between an NPN and a PNP transistor, but it's not required to be an amateur, even if today's amateur education system still requires it. So what I'm saying is that, you should build a circuit, build a radio, go on to build a transceiver. You should understand what goes on under the hood because it helps you understand the implications of things when you make changes. Just like a racing car driver has no understanding of the chemistry of the fuel that is put in his car, there should be no...

Picking better language to talk about our hobby ...

Dec 13, 2015 201


Foundations of Amateur Radio Today I started doing some research on Baluns. It was prompted by a message from a fellow amateur who asked about how they work and what they do and what the difference was between a 1:1, a 1:4 and a 1:9 balun. While doing that, I thought I'd look up what the definition was of a balun. It says right here on Google - so it must be true - that it's a type of electrical transformer used to connect an unbalanced circuit to a balanced one. I clicked on the link that said "Translations, word origin and more definitions", which showed me a history of the use of the word balun and I was hooked. The explanation of a balun will have to wait for another day. I started looking at the use of the word going back to the 1800's, based on Google's Ngram Viewer. Looks like it was used a bit between 1800 and 1910, but steadily declining in use, until it started picking up in popularity around 1930. Today the word balun is more popular than the phrase "radio amateur", but less popular than either "amateur radio" or "ham radio". Radio Amateur hit its peak in 1950 and Amateur Radio in 1990, when electronics also hit its peak. Ham radio hit its peak around 2000. All of these terms pale into insignificance when compared with either the word Software or Hardware. Hardware being about 200 times more popular than any of the radio terms, but software being 700 times more popular. So, what does this have to do with us, more specifically, what does this mean for you? Well, if you want this amazing hobby to relate to the people around you, there might be a benefit to use language that is increasing in popularity, while still related to us, it might pull us along with the tide. So, "Software Defined Radio" is on the rise, SDR likely means something else in 1985 when it hits peak popularity, but use is increasing. Interestingly, Icom makes more noise in literature than Yeasu, by about 9 times. The ARRL makes more noise than the RSGB and WIA put together and balanced is 8 times more popular than unbalanced, though I won't vouch for that relating only to amateur radio. Transistors hit their peak in 1967, capacitors did so a decade earlier, resistors even earlier in 1952. I think this means that we need to spend some time investigating the language we use to communicate about our hobby and use it wisely to increase awareness about the things we think are amazing. GPS is a term on the rise, antenna is pretty stable since 1965, emergency response is on the increase, communication is at an all-time-high, steadily increasing from 1900 on-wards. Radio is staying pretty stable, but hit its peak in 1950. Television is on the decline and the Internet is more popular than either. So, pick some words, look at the Google Ngram Viewer [https://books.google.com/ngrams] and learn some things about the words you might use to communicate about this wonderful hobby. Can you guess, what's more popular, a dipole, a vertical or a Yagi? I'm Onno VK6FLAB

Radios are not quite appliances ...

Dec 6, 2015 153


Foundations of Amateur Radio Today we have a world where radios are more and more like appliances. We can buy them at a store, ship them to our location, open the box, plug in the radio to an antenna and start operating. I said, "like" an appliance, because a transceiver is not like a toaster in all aspects and it's those little gaps between the toaster as an appliance and a transceiver as an appliance that I want to highlight. I was with a farmer recently who had a CB radio in his troopie, or if you're not familiar with that, a Toyota Land Cruiser, this one had 400.000km on the clock and was just getting run in. According to the farmer, the CB had never worked right. He joked that it was often easier to yell across the paddock than to use the radio. On a farm there are lots of things happening, during harvesting, heavy equipment is moving everywhere and communications are vital. I was with a friend and the first thing that we noticed about this CB is that it was a UHF CB, that is, it was using 70cm, or 470-odd MHz. The antenna however was a HF CB antenna, 27 MHz. As a radio amateur you know that this is never going to work well. In fact it's amazing that there was any contact using this particular CB at all. Another thing we noticed was that the connector between the radio and the antenna was loose, so it's entirely possible that the actual communication was happening around the connector on the back of the radio, rather than the antenna on the bull-bar. You might be listening to this and shaking your head. If you're uncharitable, you might even scoff at those silly CB'ers. I think that's both unhelpful and wrong. Precisely this is the difference between a toaster as an appliance and a transceiver as an appliance. It means that any radio training, any license at all, even a foundation call, is sufficient to learn enough to be able to diagnose such issues. You might think that this means that I think CB'ers are stupid. Far from it. I think this means that radios are not appliances and that there is ample opportunity for the skills we take for granted as amateurs to propagate through the community. If you're a CB'er yourself and you're not a radio amateur. Perhaps you might consider spending a weekend and getting your introduction to Amateur Radio. You are likely to learn lots of things you've never heard or understood, or more likely have been told incorrectly. If learning how to use your transceiver, be it CB, HF club or otherwise, is important to you, have a look at Amateur Radio. I think it's important. I'm Onno VK6FLAB

Fieldstrength and Chickens

Nov 29, 2015 175


Foundations of Amateur Radio Yesterday during dinner I heard an interesting story. Apparently there was a farmer who had a chicken coop that he kept warm at night by using a 240 Volt light bulb hooked up to the chicken wire surrounding his chickens. The farmer's property was in the vicinity of a local AM broadcast transmitter. They only found him because the people in the shadow of the chicken coop had bad reception. I'm sitting at the dining table, listening to this tale and wondering, could it be true? My gut feeling was no, but surrounded by food and friends it was hard to put my finger on precisely where this doesn't add up. A little digging revealed that the transmitter in question was the local ABC 6WF transmitter at Hamersley. So, what do we know about this transmitter? First of all, it's a 50 kW AM transmitter. I must confess, I have operated this station. Imagine that, 50 kW AM, with an introductory Foundation License. Anyway, back to the 6WF transmitter. It's located on a block of land, roughly 500 meters wide, 1000 meters long. Thanks to the ACMA we have a map that shows a contour line where the field strength of this transmitter is 1 Volt per meter. That means that there is 1 Volt difference between two points a meter apart. This contour varies in distance from the antenna from 2.1 km to 1.8 km. So in a sort-of-circle around this transmitter there is a circle of points at which you can step 1 m further away and measure a field strength decrease of 1 Volt. We also know that electric fields decrease by the inverse square of the distance, or said in another way, if you double the distance, you decrease the field strength by 4, if you increase distance by 3, you decrease strength by 9. Of course, the opposite is also true. If you halve the distance, from 2 km to 1 km, you increase the field strength to 4 V/m. If you have it again to 500 m, the field strength becomes 16 V/m. To power a 240 V lamp, we'd need to get within 100 meters or so of the transmitter. Of course, the block is 500 m wide, the closest you can get without going onto the property is about 250 m, where the field strength is about 64 V/m. So, unless the farmer had a chicken coop on the transmission site itself, this is unlikely to have happened. Before you ask, how can an f-call operate a 50 kW AM transmitter, on 720 kHz, easy, get invited to talk about Amateur Radio with Gillian O'Shaughnessy on ABC breakfast radio. Did you know, her grand-dad was an amateur? Anyway, if you know the farmer in question, or if you're sure it's happened, I'd love to hear about it. I'm Onno VK6FLAB

Change one thing at a time ...

Nov 22, 2015 146


Foundations of Amateur Radio Whenever I go out to play radio, which is whenever I actually want to operate, I try new things. For example I've experimented with different clocks, to keep track of what time I made a contact, I've experimented with different ways of logging, with different locations, different antennas, with different bands, times of day, methods of calling CQ, methods of making a contact with a DX station, different methods of looking at propagation, different distances from interference. As I said, every time I try something else different. One thing I do, that might not seem obvious. I try to only change one thing. The reason I do that, is so I have a better understanding on what the change actually did. Of course this isn't entirely possible, you often cannot park in exactly the same spot, at the same time with the same propagation, but if you go out often enough, things start coming together. So, for a clock, I use a $20 digital watch that has two time-zones. I set it to show local and UTC at the same time. For logging I use a spiral notepad. I write the date on a new page, the location, the radio, the antenna, the maidenhead locator and anything new I'm trialling. When I listen up and down the band, I'll write down each callsign I hear, their frequency and a signal report. If I manage to make contact, which as a QRP station can be a rewarding challenge, I'll add the time, their signal report and some other information they share, like their name and location. I'll also add two exclamation marks in the margin, so I know that I need to log this contact in my logging software. I tried using my phone, but logging software is not that good, a computer runs out of battery before you make your first contact, or just goes to sleep when you get a signal report and nothing beats looking at your wrist for seeing what time it is right now. Antenna wise, I'm still fooling around with my mono-band verticals, it's been over a year now and while frustrating, I'm still learning about what they do and don't do. I ask most amateurs I come across about their opinion and have been given lots of great and some dud information along the way. All in all, most of my activity is about learning. Every now and then I manage a DX contact and that's very rewarding. Meanwhile, the hunt for Morse continues. I'm Onno VK6FLAB

How to get started in a contest

Nov 15, 2015 146


Foundations of Amateur Radio There are times when you'll find yourself being encouraged to participate in a contest. You might receive an email, a Facebook encouragement, or even hear an item on the local news about a contest. Where do you start if that's what you're interested in? Well, first things first. You need to find out when this contest is exactly. The reason this is important is because you might go though all the preparation, only to find yourself sitting at a family BBQ listening to your favourite family member sharing the story about the dog and the lake, rather than being in the contest. Once you've determined that you are in fact able to participate in the contest, put it in your diary. This seems obvious, but I can guarantee you that there will come a day when you're happily sitting in the sun having lunch when that sinking feeling appears and you realise that the contest you were going to play in started 8 hours ago. Now that you've got the basics out of the way, what's next? Find the contest website, most contests have one, in fact I can't think of one that doesn't, and look at what the aims and objectives of the contest are. Download a copy of the rules and see if there are things that exclude you from operating. The contest might be on bands you're not allowed on, or modes you're not licensed for, so make sure that you're actually allowed to participate. Then read the rules of the contest for understanding. Most contests define who is allowed to contact whom at what time, on what frequency and how often. The rules will outline how points are calculated and how the log needs to be submitted. Other things you'll find are the deadline for log submission, the exclusions, power requirements, bonus points for low power operation, things like operating more than one radio, or having more than one operator. Terms you'll come across are SO2R, or Single Operator Two Radios. Or Multi-Multi which means Multiple Operators with Multiple Radios, or Multi-Single, meaning Multiple Operators, One Radio and all manner of special classes as defined by the contest manager. Previously I've talked about getting logging software together, setting up your station and testing it, but those things all need to be covered off. Make sure your computer doesn't need a Windows Update in the middle of the contest, get enough sleep before the festivities and plan for some recovery time after the contest. This of course doesn't cover all of what you need, but it's a really good start. Get on air and make some noise. I'm Onno VK6FLAB

Tools in my shack

Nov 8, 2015 155


Foundations of Amateur Radio Today I was looking around my shack and noticed that I have lots of different amateur radio tools that go beyond the simple bits and pieces that I started with, namely a radio, battery, power supply, coax and antenna. While I have no illusion that my gear is complete, or even representative of all of the stuff that you might need or come across, I think that it's worth while to mention a few bits and pieces that you may not have considered. I think the first thing I got that wasn't part of the basic kit, was a dummy load. It's only a little one, rated at 50 Watts or so, but seeing that I'm only using 5, that's more than enough. I use it to check things like VOX sensitivity, that is, I want to set-up a way to talk into my radio without having to push a button - for when I'm doing a contest, and I don't actually want to transmit any signal while testing, so I plug in the dummy load and test with that. I also use it to plug into the end of a piece of coax that I'm testing. I can tell you, it's helped me find some dodgy coax over the years. I have a range of adaptors, from PL259, SO239, N-type, SMA, BNC, male-to-male, male-to-female, female-to-female, all different permutations. They're all in one box and I have that with me whenever I go portable, it's saved my bacon more times than I can remember. I have a multi-meter, the most often used part of it is the continuity beep. You can set it to beep if there is a short, which is great for testing power leads, coax shorts and the like. I splurged and purchased an antenna analyser. It's helping me understand the errors of my ways while building antennas, though I confess that on more than one occasion it added to the confusion. I have a coax cutter, a pair of high quality pliers, though one of my so called friends left it in the rain one day, so they're less quality than they were, an Anderson Powerpole crimper, a gas soldering iron - so you can solder in the field, a third-hand, since holding something while soldering is an excellent way to get a scar to impress your friends. On my workbench I have a lighted magnifying glass, since the older I get the harder it is to focus on small things. I have a bag of clip-on torroids which I use in places where operating surprises me with bonus RF interference. I also have stuff like cable-ties, electrical tape, self-amalgamating tape and a fair bit of rope. You'll notice that I don't have an SWR meter, I figured that the one in my radio and the antenna analyser combined were enough. I'm sure there are other things that I take for granted, but the items I've outlined are in regular use. I'm Onno VK6FLAB

Wet string and 10 Watts

Nov 1, 2015 162


Foundations of Amateur Radio Today I had the pleasure of talking to a group of freshly minted Amateurs. It's a semi-regular occurrence where I visit a local club that offers training to obtain an Amateur License. I should mention that you'll find clubs like this all over the place and there are often opportunities to do remote examinations if you're too far from an assessor. This however isn't about becoming an Amateur, that's something that I'll leave entirely up to you, even if I think that being an Amateur is a wonderful thing. One of the things I like about this hobby is that it's different things to different people. There is a huge variety of aspects to this pursuit of Amateur Radio and as I've said in the past, it's really a thousand hobbies rolled into one. In Australia there are three so-called classes of license, think of it as a moped licence, a car license and a truck license. If you want to drive a truck you need that one, but if you're on a moped, there's no need to spend your efforts on learning to double-de-clutch a Ranger gearbox - something I can assure you from personal experience is hard to master, but fun to get right. The three licenses in Australia, Foundation, Standard and Advanced each have different privileges, access to different but overlapping aspects of the hobby. One privilege within the class of license that I hold, the Foundation or F-call, is that I'm limited to using 10 Watts. I've spoken about this restriction many times, in fact, the very first time I shared my opinion about this hobby in this forum was exactly about those pesky 10 Watts and what is possible with them. Back to the freshly minted Amateurs. It occurred to me that while I was explaining the amazing width and breadth of our hobby, that the 10 Watts, while completely arbitrary, and often lambasted for being so, is actually a blessing in disguise. When you get on air, or if you already have the privilege to do so, you'll learn or already know that making contacts with a wet piece of string is pretty hard, nigh on impossible with 10 Watts. One solution is to add more power. A better, more elegant solution, is to get a better antenna. So, the blessing in disguise that 10 Watts represents is really all about forcing a Foundation Licensee to spend considerable effort in their antenna system. Something which we might all agree on is a good thing, if only to clear the air of alligators, big mouth, no ears. I'll take the risk of repeating myself. It's not how much power, but what you do with it that matters. I'm Onno VK6FLAB

Propagation and reality

Oct 25, 2015 125


Foundations of Amateur Radio A recurring topic of conversation is propagation. There is learned discussion about sun-spots, A and K indices, forecasts, ionospheric probing, not to mention half-baked guess work from less scientific perspectives. It's been my experience that all these tools are wonderful, but none of them beat turning on your radio and having a listen, or better still putting out a call. So when do you listen and where do you listen? The trivial response would be everywhere, all the time, but none of us has enough time for that. In general, 20m, 14 MHz works most of the time. At night, frequencies lower than 20m, that is 40m, 7 MHz and 80m 3.5 MHz work better. During the day, higher frequencies, 15m, 21 MHz and 10m, 28 MHz work better. Of course this is not a hard and fast rule. As I said previously, there is no such thing as a perfect antenna, in fact we can prove that it cannot actually exist. Similarly, there is no such thing as perfect propagation. We tend to think of propagation in terms of layers in the ionosphere, the D, E and F layers. We might think of them as specific, distinct things, but the reality is that they're more like clouds. Clouds are not uniform in cover, sometimes fluffy, other times dense thunderclouds and an infinite variety in between. Coverage is variable and forecasting is a real challenge. And that's for something we can see. The ionosphere is no different. It's not uniform, it's not predictable and forecasting is hard. Back to the clouds for a moment; you might have a forecast for rain, but it's perfectly dry where you are. Similarly, you might have a forecast of poor propagation, but it's perfectly fine where you are. So, best tip is to use the forecasts you have access to, but stick your head out of the window to see if it's raining right now. If that was too obscure, turn on your radio and make some noise, even if the sunspot count is rubbish and the Ionospheric Prediction Service tells you that nothing is going to work. I'm Onno VK6FLAB

Getting started with portable operation

Oct 18, 2015 151


Foundations of Amateur Radio Today I'm operating portable, in fact I'm operating portable every day. Though I'd have to confess, some days more than others. I have to do this by necessity. There is lots of RF noise at home, so I'm forced to physically move away from the interference and set up elsewhere. You can do this as simply or as complex as you like. I've done it with a bag that contained my radio, a battery and a wire antenna that I strung between two trees. I've also gone portable with my car, camping gear, a trailer full of radio gear, a wind up mast and a rotatable dipole with a generator to provide power. And everything in between. My point is that for every circumstance there is a different set of tools that will solve your problem. Several amateurs I've spoken to are quite unsure about this portable adventure and are not really geared up for such shenanigans even if they're interested to get out and about. So what is involved with going portable? The essence of any station is the antenna. If you know where you're going to operate and why, you can figure out what kind and how much of an antenna you need to bring. Likely a mast and rotator are not part of the deal, but I have set up a yagi on mast in a park for a contest. If you don't know where you're going to be, you need to come up with a solution that is more flexible. Either a self supporting vertical with something like a squid pole or a wire antenna that you can throw into a tree. The next challenge is power. Are you going to operate for a little while or are you going to set up for 48 hours to participate in a contest. Are you going to be using low power, 5 watts, or are you in a position where you can give an amplifier a workout? Batteries, generators, your car or a solar panel, all of these can power your radio in different situations. Are you planning to make a few contacts, or are you expecting a huge pileup to get your blood pumping? Logging for either requires a different solution. You should always, always consider the weather when you're operating portable. Sun, wind, rain, storm, hot and cold all have different implications for you personally and the wear and tear of your equipment. So prepare yourself. Just like when you started your shack, you had to figure out what goes where and how will I use it? Portable operation is no different. A tip for new players, less is more. You have to carry all this stuff, so expect to make compromises. You won't be able to take everything in your shack, unless you already built it in the back of your vehicle, in which case I'd like an invite to come and visit. I'm Onno VK6FLAB

Antenna Calculators

Oct 11, 2015 195


Foundations of Amateur Radio Recently I was asked about finding the best antenna calculator. It's a tool that helps you determine what the length of an antenna should be for a particular frequency. Picture a dipole antenna, two wires, end to end, strung out horizontally, joined in the middle by a feed point. A dipole is most effective if its total length is half of the wavelength of the frequency it's intended for. To calculate what that is, you divide the speed of light by the frequency. So, for argument sake, the wavelength for 28.5 MHz is roughly 10 m, which makes sense, since 28.5 MHz is in the 10 m band. If you use your favourite search engine to find a dipole calculator, you'll find many different ones. If you try a few, you'll find that the answers that each calculator gives is slightly different. For a half-wave dipole on 28.5 MHz, you'll find that there is a half meter variation among the calculated answers. If you do this for a dipole for 3.5 MHz, you'll find the variation is just over 4 m between the shortest calculated dipole and the longest one. That's a 5% variation across a calculated response. That's strange, since the calculation should be the same across all different calculators. So what's going on? Let's start with the wave length. If you use the speed of light as 300.000 km per second, then a frequency of 28.5 MHz is 10.526 m, but if you use the actual speed of light, there's a 7mm difference. Right, simple, so there should be two types of answers, those that use 300.000 km per second and those that use the actual speed. Unfortunately, no. You could use "majority rules" and pick the calculated answer that turns up most often, but science isn't a democracy. It's either correct or it ain't and you have no way of knowing which is which. What you're actually witnessing when you see all these answers with the overall 5% spread is different approximations of the answer. Calculator is a word that implies precision and accuracy, but what's actually happening is that each calculator uses their own fudge factor to get closer to the starting point. It's all in an attempt to get to an actual answer quicker, since hoisting an antenna, measuring, lowering it, trimming it, hoisting it again and so-on, is not fun with a 10m antenna, let alone an 80m antenna. Some of the fudge is related to how high the antenna is off the ground, the thickness of the wire used, if the wire has insulation on it and how thick that insulation is, what the soil type is and what angle it's actually hanging at and how far it's from other things. What this really means is that you need to experiment. When you buy wire, buy long, cut in little bits, measure lots and try it. A calculator will get you in the ball-park, but you already know the nominal length for a dipole as it is, it's right there, in the band name. So, just because you've found a fancy calculator online, doesn't make it right for your circumstance. One tip, plot all the antenna length results from the various calculators and see what the curve looks like, you'll see a wonderful distribution curve that just begs to be used. I'm Onno VK6FLAB

Use it or Lose it ... make a contact today!

Oct 4, 2015 121


Foundations of Amateur Radio In your travels around the sun it's likely you've heard the phrase: "Use it or lose it." Within the ranks of our hobby, that refers to making noise on air and using the bands we've been allocated. It's easy to sit in your shack - in what ever form that might take - turn on your radio and scan up and down the bands to see what's going on. If something interesting catches your fancy, you might even plug your microphone or key in, and actually call the other station. Unfortunately, that's not using the bands, that's sitting on the side and listening. Not that there is anything wrong with that, but it's no way to ensure that the bands and privileges we enjoy today are going to be here tomorrow. Over the past few years I've come across several ideas to change that. I've seen blogs and posts from individuals who attempt to make a contact every day, in what ever form they prefer. Some don't distinguish between local or DX contacts, portable or QRP, whatever takes their fancy. In New Zealand there's the ZL2AL Memorial Activity Marathon. You get recognition for making 4 or more contacts on a specific number of days during the year. Some amateurs are working on a single contact per day, others are attempting a QRP QSO every day. Imagine if all the amateurs in the world made one contact every week. In Australia alone that would generate 2000 extra contacts every day. You can limit your activity to making contacts when it suits, or during a contest, or on the way to work on the local repeater, or you can spread your wings and make contacts more often than that. I know for a while - until my antenna circumstances changed - I was making at least one contact a day. I kept that up for nearly a year. I'm still getting the QSL cards coming in the mail. So, don't wait for permission to get on-air. Don't wait for "just the right conditions", turn on your radio, plug in your microphone and make a contact. Why not do it right now? I'm Onno VK6FLAB

Propagation predictions and operating your radio

Sep 27, 2015 176


Foundations of Amateur Radio Today propagation is what it is, yesterday it was different and tomorrow it will be different again. It's one of the fundamental aspects of amateur radio. We talk about propagation on air, like we do the weather. Rain, sun, snow or storm, there's always something. Of course most of those weather events have no impact on radio. A rain drop isn't going to make a great deal of difference to a HF signal, other than potentially making the operator wet, or creating a short-circuit in an unexpected way. Propagation on the other hand has little or no effect in day-to-day life, other than your GPS, mobile phone or other electronic device. In radio however, propagation makes the difference between only hearing your neighbours and speaking to another station on the other side of the globe. In the past I've mentioned that if you skip a stone across a lake, you get a good idea about how radio waves bounce off the ionosphere and in doing so, make it possible to hear and be heard beyond the line of sight of your antenna. A stone is a fixed object and water has a pretty uniform density, so you get mostly predictable results. The ionosphere is not uniform and radio waves are not fixed, so the result is anything but predictable. That said, a great number of people are working on providing propagation prediction tools in an attempt to provide us with somewhat more of a reliable outcome. Once you step into this area, you'll come across the A and K indices, the Solar Flux and Geomagnetic and Solar Flare numbers. You'll find websites like solarham.com, bandconditions.com, spaceweather.tv and many others. Sometimes they'll even agree with each other - which is interesting in itself, since the source of actual data is pretty limited. We have the Ionospheric Prediction Service or IPS in Australia, in the US there's the National Oceanic and Atmospheric Administration, or NOAA. All this is to attempt to quantify what the sun is doing and how this affects the ionosphere and in turn our experience as radio operators. If you know anything about predicting the weather, that is, what is the temperature going to be today and is it going to rain, you'll understand that predicting solar activity and its impact on us is a less than perfect experience. In 1959 we managed to snap the first images of the far side of the Moon, it took until 2011 for us to do the same with the sun. Many of our predictions are really observations and imperfect ones at that, coming from the two STEREO spacecraft, one orbiting the sun ahead of the earth, the other behind the earth, combined they manage to cover the back of the sun. In the end, the predictions on carrying an umbrella or not are like predicting whether to operate or not. It's a prediction. Nothing beats turning on your radio and having a go. I'm Onno VK6FLAB

Every Antenna is a Compromise!

Sep 20, 2015 158


Foundations of Amateur Radio Recently I read a comment a fellow amateur made about an antenna. He said: "Of course, that antenna is a compromise..." Let me say that again: "That antenna is a compromise ..." It was the funniest thing I'd seen all week and the person making the statement wasn't even trying to be funny. Unless you're looking at the Sun from a distance, or checking out the propagation associated with the Big Bang, All Antennas are a compromise. We can prove that an isotropic antenna, one that is a theoretical point source of radio waves, cannot actually exist, so that basically means that you cannot have it all, ever. Once you've got your head around the notion that no such thing as a perfect antenna actually exists, or can exist, it makes sense that amateurs around the world spend so much time discussing and trialling antennas. As you get involved in Amateur Radio, you'll soon realise that the number of variables to construct an antenna is large. The more you learn, the more variables you unearth. Initially, you'll learn that the length of the radiator will determine the resonant frequency,