Foundations Of Amateur Radio

Foundations of Amateur Radio The pursuit of amateur radio is a glorious thing. On the face of it you're forgiven if you think of it as a purely technical endeavour. Far be it for me to dissuade you from that notion, but permit me to expand into other areas that rarely get a mention when we discuss this amazing hobby. It's the place where you go to communicate with other people, who live a different life, doing the things that they enjoy. It's also the place for finding an excuse to go outside and set-up your station on the side of a mountain, or a park, a museum or a lighthouse. Then there's the joy of finding new friends who introduce you to other aspects of life, super computing, the medical field, tow truck driving, radio astronomy and electronics, to name a few. While I was the first person in my school to save up their summer job earnings to buy their own computer, a Commodore VIC-20, I never did come across this. "It is pitch black. You are likely to be eaten by a grue." is a phrase that might mea

Foundations of Amateur Radio The other day I came across an article written by programmer, artist, and game designer "blinry" with the intriguing title: "Fifty Things you can do with a Software Defined Radio". Documenting a weeks' worth of joyous wandering through the radio spectrum it explains in readily accessible terms how they used an RTL-SDR dongle to explore the myriad radio transmissions that surround us all day and every day. As you might know, I've been a radio amateur since 2010 and I must confess, even with all the things I've done and documented here, there's plenty in this adventure guide that I've yet to attempt. For example, when was the last time you decoded the various sub-carriers in an FM broadcast signal, including the pilot tone, the stereo signal, station meta and road traffic information? Have you ever decoded the 433 MHz sensor signals that your neighbours might have installed, weather, security and other gadgets? Or decoded shipping data, transmitted using AIS, or Automatic Ident

Foundations of Amateur Radio The other day I went for a walk, I know, shock-horror, outside, daylight, nature, the whole thing, in a local national park, for the first time in too many years. Almost immediately I noticed that this would be an excellent location for an activation. If you're not familiar, it's an amateur radio excuse to set-up a portable station in a new location, in this case, potentially something called POTA, or Parks On The Air, but you don't need to find a formal activity with rules to get on air and make noise. I commented on how easily accessible it was, that it had picnic tables, gazebos for shelter, nearby toilets, free BBQs, ample parking, lots of open space, and no overhead power lines. I saw one solar panel on a pole and no evidence of any other electrical noise sources. It wasn't until later that I realised the act of noticing this, in that way, with those details, is not something I would have done before becoming a radio amateur. I'd have looked at the same location, considere

Foundations of Amateur Radio I've owned a Yaesu FT-857d radio since becoming an amateur and at the time I was absolutely blown away by how much radio fits inside the box. It's smaller than most of the commercial radios I'd seen when I bought it. I came across a video by Michael KB9VBR, the other day showcasing a wooden cigar box with a complete, well, almost complete POTA, or Parks On The Air, activation kit. I say almost, since Dave KZ9V, the owner of the kit, points out that the box doesn't contain an antenna. It made me wonder how small is small? According to RigPix, the lightest transmitter on an amateur band, in this case, the 5 GHz or 5cm band, is an Amateur TV transmitter. Weighing in at 3.9 grams. The Eachine TX-06 is capable of FM with about 18 MHz of bandwidth with an audio sub-carrier. Of course, that's not a transceiver, but I thought it worth mentioning in case you needed an excuse for something tiny in your shack, besides, as far as I can tell, there's never too much Amateur TV in the world

Foundations of Amateur Radio Over the past nine months or so I've been working on a project that I've called Bald Yak. If you're unfamiliar, the Bald Yak project aims to create a modular, bidirectional and distributed signal processing and control system that leverages GNU Radio. One of the, admittedly many, challenges I've set myself is getting data from a radio receiver into GNU Radio across the network, preferably the Internet. Today I can report a small step in the right direction and frankly I can't contain my excitement. Now, I need to acknowledge that I'm geeking out here. It's hard to contain excitement when you find something that seems to speak your language. It also means that I realise that I run the very real risk that I'm going to lose you before you get to why this is a milestone, so let's put that up front before I explain why. To whet your appetite, yes, you can access a KiwiSDR across the Internet and record raw data from it and control the process externally. This is a very big chunk of

Foundations of Amateur Radio The other day I stumbled on a random post by Gary N8DMT which caused me to view the world in a different way. The post outlined combining a PlutoSDR and an application called SATSAGEN to measure the frequency characteristics of a coupler. Aside from a detailed description, the post includes a couple of excellent photos showing the PlutoSDR connected to the coupler and the output piped back into the Pluto. Before I continue, a PlutoSDR is a Software Defined Radio or SDR, officially it's called the ADALM Pluto Software Defined Radio Active Learning Module. It's essentially a full-duplex radio and computer in a box. It runs Linux and connects to the world via USB, and of course radio, unofficially between 70 MHz and 6 GHz. I've talked about this device before. When I say full-duplex, I mean that it can transmit and receive at the same time. Gary's post triggered something unexpected in me. The notion that you could use two patch leads, one connected to the transmitter, the other

Foundations of Amateur Radio Recently I discussed the idea of listening to the radio spectrum across the internet for the purposes of getting signal into your shack when radios, or in my case, antennas are causing you challenges. I continued to explore and discovered a project by Jacobo EA1ITI, called "radioreceiver". Behind that unassuming name lies a tool born in 2014, that allows you to plug an RTL-SDR dongle into your computer, open up your web-browser, and listen to the radio signals that your dongle can receive. In case you're unfamiliar, an RTL-SDR dongle is a small USB device, looks a lot like a USB thumb drive, jump drive, data stick or flash drive, basically a hunk of plastic with a USB connector on it. An RTL-SDR dongle generally also has some form of antenna connector. It's typically sold as a digital radio and digital television receiver, but websites like rtl-sdr.com sell purpose built ones. They can be found starting at about $15. I realise that this is using a local receiver, with a local

Foundations of Amateur Radio One of the many challenges associated with being a radio amateur is actually being able to listen to weak signals. If you're like me and more than half the planet, you live in an urban area, which comes with the benefits and pitfalls of having neighbours. From a radio perspective, there's plenty of noise that drowns out weak signals, so more and more amateurs are finding new and interesting ways to deal with this. Over the years I've talked plenty about so-called web-sdr, or internet accessible software defined radios. Essentially a radio receiver, preferably in a radio quiet area, hooked up to some software that allows you to listen in using a web browser. There's thousands of internet based services across the globe, the most popular of those are websdr.org and kiwisdr.com. As a new amateur you might have visited one or more of these and tuned around to listen to various radio stations and QSOs or contacts between amateurs, on bands that you can't access because you don't ha

Foundations of Amateur Radio Every single radio amateur has come to this hobby with an itch to scratch. Time and again I've seen amateurs around me pursue that particular purpose, only to come out the other end with a look of bewilderment writ large across their face. For some amateurs it means the end of their involvement in the hobby, for others it starts a new journey into the unknown. One of the ways we explore our community is by travelling out of our shack into the big outdoors in whatever form that takes. Popular activities include setting up a radio in a location and talking to others, known colloquially as an "activation". We do this all over the planet. Perhaps the most recognisable of these is IOTA, or Islands On The Air, where a station is erected on an island and contacts are made. As amateurs we cannot help ourselves and seem to have an insatiable need to measure our prowess. We do this by counting how many contacts, callsigns, countries, grid-squares, or in this case, islands, we've managed t

Foundations of Amateur Radio Recently I came across a series of strident posts about the injustice associated with a non-amateur service using the 70cm band. Complete with links to discussions, spectrum plots, angst and even incoherent outrage, all related to the notion that whomever "allowed" this user to transmit on this band was clearly incompetent. Except, that this is probably not the case, or the full story. So, what's going on and why are people incensed? This all started at least six years ago. Since then AST SpaceMobile has deployed seven low Earth orbit satellites and used the 70cm band to communicate with them. Although in the trial phase, there's plans for an additional 243 satellites, and there's at least one other company playing in the same space, Atmos Space Cargo. The outcry from amateurs is around the commercial use of "their" 70cm amateur band. It's an emotional statement, but what is the reality? Before I dig in, let's set some terms. Radio frequencies are globally coordinated becaus

Foundations of Amateur Radio In the community of radio amateurs scattered around the planet we have a habit of getting together with others to have fun in whatever shape that takes. The obvious ones are HAMfests, car boot sales, raffles and other amateur adjacent pursuits, but we also do things like licence training, weekly on-air nets, contesting, portable activations, climbing mountains, or hills, setting-up in parks, or lighthouses, we set-up on a field day, just for fun, and find excuses, sorry, reasons, for any number of other activities. Some of these are solitary affairs, but many are best enjoyed shared with multiple friends, both old and new ones. Having been a member of this community since 2010 I've come to observe an aspect of this community that is odd, to say the least. We organise all these events, but rarely promote it beyond a single email to three people, if that. It's almost as-if the average organiser thinks that their event permeates the community by magic osmosis. Even if there is an

Foundations of Amateur Radio Recently I was given some radio data captured on the 40m band. Using a piece of software called "Universal Radio Hacker", I attempted to decode it. At the time I thought that this might be Morse code, since then I've been told by someone who has been using Morse longer than I've been alive, that it isn't. I shared the data on my VK6FLAB GitHub repository where you can download it and see what you learn, and perhaps repeat what I did, or better still, improve on it. Over the years I've talked a little about how Software Defined Radio or SDR works, essentially it's a glorified Analogue to Digital converter, much like the sound card in your computer, which does the same, albeit at a much lower frequency. As it happens, you can represent the signal that comes into your radio antenna as a series of values. Essentially, the stronger the signal, the bigger the number, the weaker the signal, the lower the number. Let's talk about the characteristics of this signal. It consists of two

Foundations of Amateur Radio Recently I was helping a friend erect their newly refurbished multi-band antenna and during the process we discussed the notion of tuning an antenna that's high in the air. They made a curious response, in that they'd tuned the antenna on the ground before we started. I asked how this would work, since as I understand the process, this changes things once it gets in the air. They assured me that while the actual SWR might change, the frequencies at which it was resonant would not. This was news to me because I've been putting off erecting my own multi-band 6BTV antenna mainly because I didn't really want to face having to erect it, tune it, lower it, modify the elements, erect it, tune it, etc., all whilst standing on the steel roof of my patio. Would this phenomenon be true for my antenna? It occurred to me that I could test this idea, not only for my antenna, but for other antennas as well. In my minds-eye, I saw a video displaying the pertinent attributes of an antenna, SWR

Foundations of Amateur Radio Just over a year ago, the ARRL, the American Radio Relay League, the peak body for amateur radio in the United States and one of the oldest of such organisations, experienced an incident. During the weeks following, the ARRL was tight-lipped about the extent of the incident and most amateurs only really noticed that services were off-line or slow to respond. After months of delay and disinformation, the ARRL finally revealed that it was the subject of a ransomware attack and that it had paid a million dollar ransom. It went on to blame the authorities for its silence. Mind you, it didn't tell me personally, it made public statements on its website. Similarly when I specifically contacted the ARRL to discover what information of mine it held, and what the status of that information was, the ARRL responded that I should refer to its public statements. It continued to state that my information was not compromised, since it only lived in LoTW, the Logbook of The World, the system i

Foundations of Amateur Radio The other day Randall, VK6WR, encouraged me to get on-air. He described it like this: "There is a mystery signal on 40m that you can try your new Universal Radio Hacker skills on. It appears to be a FSK signal separated by 7kHz with the two signals at 7.0615 and 7.0685 MHz. Each of them on their own sounds a bit like a Morse signal, but my CW decoder decodes junk. But if you can see it on a spectrum scope, it is clearly FSK because either one of them is on at any time." He went on to say: "You'll need an SDR to receive the signal given the separation, but could be a fun investigation!" Having just discovered "Universal Radio Hacker", a tool that can help you decode radio signals, that sounded like something I'd love to have a go at. Unfortunately, after the demise of my main workstation last year, my current set-up doesn't allow me to do such recordings, but Randall, ever the gentleman, provided a recording of the signal. He writes: "This was captured with gqrx demodulating t

Foundations of Amateur Radio The other day I was discussing with a fellow amateur the increased frustration my mobile phone provider was inflicting. We hit on the idea of figuring out if other providers would fit the bill and how we could determine if their coverage would suit our needs. Aside from using an old mobile phone, I suggested that using a $25 RTL-SDR dongle would provide a way to record mobile phone cell site beacons from the various mobile networks to map what signal levels we might find. To that end, I discovered a tool called LTE-Cell-Scanner by Xianjun BH1RXH. Forked from the original project by James Peroulas, it allows you to use simple hardware to scan for LTE Cells used by mobile phone networks. James points out on his site that this tool can also be used to calibrate an RTL-SDR receiver's oscillator, since an LTE downlink centre frequency is stable to within 50 Parts Per Billion, that's 10 times more stable than my Yaesu FT-857d using a TCXO. If this doesn't mean much, think of it as a

Foundations of Amateur Radio The other day a fellow amateur asked me to help them with lowering their radio mast so they could do some maintenance on the antennas attached to it. This is not the first time I've been a participant in such an activity, but it was the first time I felt explicitly safe. Don't get me wrong, on previous occasions nothing bad happened, but there was always an undertone of "what-if" and an associated anxiety. This time was different. Before we did anything, we sat down, had a cup of coffee, talked and discussed what was going to happen. After coffee we looked at specifics and discussed the process in detail. Then we prepared. Clipping cable ties, winding up loose ends, disconnecting coax, and securing a pulley to a tree. We ran a winch line, discussed distances, looked at potential snags and coax lengths and angles, considered what would happen if something unexpected might happen and discussed various safety considerations, like never walking below the mast whilst it was in its mo

Foundations of Amateur Radio The other day a report in "Amateur Radio Daily" caught my eye. Under the heading "IARU Considers Consolidation", I read that the International Amateur Radio Union, celebrating 100 years of representing our hobby, is considering significant change. Links in the report reveal a PDF document titled "IARU Consultation on Proposed Restructuring March 2025". The document, dated 21 March, outlines the structure of the IARU, four organisations, one for each ITU Region, and one global organisation, the International Secretariat. It provides some insights on how the funding arrangements between these organisations exist and goes on to talk about how the IARU operates, including incorporation, or not, currencies, committees, priorities and other background and historic information. All excellent. Stuff that should be public knowledge, but having spent the better part of a year reading IARU documents, this one brought several new eye opening things to the table. The document attributes no

Foundations of Amateur Radio Right off the bat, let me start with a question. "What do you think you're doing?" To give you some context, it should come as no surprise that I'm talking about amateur radio and what it is that we do, you and I, when we "do amateur radio". Of course the answer is different for every person you ask, and it's likely to change over time. So, let's explore and fair warning, if you know me at all, you'll realise that I'll be asking more questions, so here goes. Is this an activity that you do, for yourself, or for others? Is it a hobby, or a vocation, or something else? Do you use this as part of your life outside this community and if you do, how? At this point I hope you're getting a sense of Deja-Vu all over again, in that I'm asking you to explore your own place in the community. I'm asking because it occurs to me that we spend an awful lot of time looking in the other direction. How do we compare skills and knowledge against other amateurs, how does our shack compare with

Foundations of Amateur Radio Around the world are thousands of associations, groups of people, clubs if you like, that represent radio amateurs. Some of those associations are anointed with a special status, that of "member society" or "peak body", which allows them to represent their country with their own governments and on the international stage to the ITU, the International Telecommunications Union, through a global organisation, the IARU, the International Amateur Radio Union. Some of these are known across our whole community, the ARRL in the USA, the RSGB in the UK, and the WIA in Australia. Some much less so, the CRAC, the Chinese Radio Amateurs Club, or the ARSI, the Amateur Radio Society of India, for example. In an attempt to get a deeper understanding of what distinguishes these organisations, I visited a dozen member society websites. Cultural sensibilities and aesthetics aside, the variety and sense of priority is both pleasing and astounding. Starting close to home, the WIA, the Wireless I