Foundations of Amateur Radio

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Brand New Callsign Jan 27, 2019

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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 20, 2019

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Foundations of Amateur Radio

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 there were 2.4 Million QSO's logged. In 2018 there were 40.4 million. In the same time CQ WW increased the number of entries by almost 200%. Interestingly, CW logs outpaced SSB logs in 2003, 2006, 2008 and 2016.

On the 31st of May 1897 Mark Twain said: The report of my death was an exaggeration. I think we can safely say that Amateur Radio isn't going anywhere and FT8 isn't killing the hobby.

I'm Onno VK6FLAB

Fan Vertical Antenna Jan 13, 2019

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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 lovely mono-band antennas I purchased so long ago. I may have to experiment with radials and tuning and no doubt there's still a gap between theory and reality, but I'll let you know how I go.

My question to you is, what antenna project are you working on?

I'm Onno VK6FLAB

Empirical evidence and the scientific method Jan 06, 2019

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Foundations of Amateur Radio

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, what is it, scientific, or empirical, or is it a little of both?

I'm Onno VK6FLAB

QRP EME project update #1 Dec 30, 2018

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Foundations of Amateur Radio

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 effective gain from having a very stable signal. You might recall I purchased a high stability compensated crystal module, a TCXO, for my radio a while back, this project is why I did that. Another thing I purchased at the time is mechanical filters which also provide a little effective gain.

We started the process of acquiring some high gain 144 MHz Yagi antennas, but through some miscommunication with the amateur who was selling them at a really nice price, we missed out and haven't yet bit the bullet on another set.

Initially when Randall and I started this, we were working on it on our own, we tried to learn as much as we could and test the waters ourselves. We've been at it now for a while and it's become apparent that this is going to be something that is likely to involve several other amateurs. Some have already been helping, Allen, Allan, Keith, Alek, Leigh and Marcin all contributed time and material. No doubt this list will grow as the project continues.

At the moment I'm still trying to write code to create a calendar of dates that will suit the radio telescope with the restrictions we have in relation to the moon, sun and galactic centre, so we can actually prove that the telescope can hear an amateur radio signal.

We'll need to source some high gain antennas, likely more than two.

Once we've done a one-way test, that is, me sending and the radio telescope hearing, we'd like to do the same but between two QRP stations.

No doubt the road ahead is paved with spikes, potholes and road-blocks, but as adventures go, this one has been sustaining me for nearly two years and so-far it's showing no signs of abating.

I'm Onno VK6FLAB

What are you proud of? Dec 23, 2018

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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 who responded, many of whom I wasn't able to squeeze in this time around. Perhaps I should do this more often.

What's your proudest moment in the past 12 months? Let me know.

I'm Onno VK6FLAB

Contest Headphones and glorious HF SSB Dec 16, 2018

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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 09, 2018

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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 02, 2018

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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 25, 2018

Show notes

Foundations of Amateur Radio

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

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