Foundations Of Amateur Radio

Foundations of Amateur Radio Since becoming a licensed amateur in 2010, I have spent a good amount of time putting together my thoughts on a weekly basis about the hobby and the community surrounding amateur radio. As you might know, my interest is eclectic, some might say random, but by enlarge, I go where the unicorns appear. Over a year ago I mentioned in passing a community called HamSCI. The label on the box is "Ham Radio Science Citizen Investigation", which gives you a sense of what this is all about. It was started by amateur radio scientists who study upper atmospheric and space physics. More formally, the HamSCI mission is the "Continuation and extension of the amateur's proven ability to contribute to the advancement of the radio art." If you visit the hamsci.org website, and you should, you'll discover dozens of universities and around 1,300 people, many of whom are licensed radio amateurs, who are asking questions and discovering answers that matter to more than just our amateur community. F

Foundations of Amateur Radio Recently I saw a social media post featuring a screenshot of some random website with pretty charts and indicators describing "current HF propagation". Aside from lacking a date, it helpfully included notations like "Solar Storm Imminent" and "Band Closed". It made me wonder, not for the first time, what the reliability of this type of notification is. Does it actually indicate what you might expect when you get on air to make noise, is it globally relevant, is the data valid or real-time? You get the idea. How do you determine the relationship between this pretty display and reality? Immediately the WSPR or Weak Signal Propagation Reporter database came to mind. It's a massive collection of signal reports capturing time, band, station and other parameters, one of which is the Signal To Noise ratio or SNR. If the number of sun spots, or a geomagnetic index change affected propagation, can we see an effect on the SNR? Although there's close on a million records per day, I'll

Foundations of Amateur Radio A recent comment by a fellow amateur sparked a train of thought that made me wonder why there is a pervasive idea within our community that you need a radio transmitter and antenna to be a radio amateur, moreover that for some reason, if you don't have either, you're not a real amateur. I suppose it's related to the often repeated trope that the internet enabled modes like Allstar Link, Echolink and even IRLP, are not real radio, despite evidence to the contrary. Instead of fighting this weird notion, I figured I'd get on with it and find a way to play even if you don't currently have the ability to erect an antenna or key a transmitter for whatever reason. Before I dig in, a WebSDR is a Software Defined Radio connected to the Internet. It allows a user to open a web browser, pick from a massive collection of receivers around the world and listen in. Some of these also have the ability to transmit, but more on that later. Here's the idea. Have you ever considered tuning to a

Foundations of Amateur Radio Over the years I've talked about different ways of using our license to transmit. I've discussed things like modes such as voice AM, FM, and SSB, and digital modes like FT8, WSPR, RTTY, FreeDV, Hellschreiber, Olivia and even Morse code. Recently it occurred to me that there is something odd about how we do this as a community. Now that I've realised this it's hard to unsee. Let me see if I can get you to the same place of wonder. Why is it that we as amateurs only use one such mode at a time? Let me say that again. With all the modes we have available to us, why do we only use one mode at a time, why do we get our brain into the mindset of one activity, stop doing that in order to move to another mode? It's weird. Amateur radio is what's called "frequency agile". What I mean by that is we are not restricted to a fixed number of channels like most, if not all other radio users. We can set our transmission frequency to whatever we want, within the restrictions imposed by our li

Foundations of Amateur Radio One of the basic aspects of being human and growing up is the process of learning. From a young age we explore our environment, play with others, have fun, fall over and bruise our knees, get up and try again. The playing aspect of this is often discussed as a way to keep things interesting. We add a competition element as an added incentive, so much so that we formaulate it into global competitions and call it sport. As a species it might surprise you that we spend about 1% of all Gross Domestic Product on sport, compared to science, which is about 2% of Global GDP. To give you some context, Agriculture accounts for about 4%, Manufacturing is 15%, Industry is about 26%, and Services account for roughly 62%. If you noticed that this is more than 100%, take it up with the World Bank, I'm a radio amateur, not an economist. Over the years I've explored different aspects of our chosen hobby of amateur radio. Time and again I return to experimentation, learning and having fun. Now I

Foundations of Amateur Radio When you join the community of radio amateurs, or when you briefly look over the shoulder of the nearest devotee, you're likely to discover that this is a hobby about a great many different ideas. Over the years I've discussed this aspect of our community repeatedly, talked about the rewards it brings you, about the camaraderie, about communication, learning, research, soldering, disaster recovery, public service, and all the other thousands of activities that this hobby represents to the world. While all those things might be true for some, they're not true for everyone. Many amateurs get excited about antennas, some immediately, some eventually. The same can be said for all the other points of what we think of when we discuss our hobby with others. Recently I saw a random comment on social media from a person who was having issues with their mobile phone on their property. I considered and ventured an opinion about what might be the cause and how they might go about discoveri

Foundations of Amateur Radio Recently I started an experiment I plan to run for a year. Using a WSPR beacon and a dummy load I'm transmitting 200 mW, 24 hours a day across all bands supported by my hardware, in this case it covers 80m, 40m, 30m, 20m, 17m, 15m, 12m, and 10m. The aim of the experiment is to determine if, and to what extent my dummy load can be heard outside my shack. Why? Because I've not seen anyone do this and because a dummy load is widely believed to not radiate, despite evidence to the contrary. Together with the transmission side, I've also configured an RTL-SDR dongle, initially with the telescopic antenna it came with, now, since my HF antenna isn't being used by the beacon, I'm using it instead. It's about five metres away from the beacon, outside. It's a helically wound whip resonant on the 40m band built by Walter VK6BCP (SK). It's what I've been using as my main antenna for the past seven years or so. While I'm telling you this, my beacon has been heard by my dongle 1,182 times a

Foundations of Amateur Radio Recently Glynn VK6PAW and I had the opportunity to play radio. This isn't something that happens often so we try to make the most of it. For our efforts we had plenty of frustrations, to the point where we were joking that I should rename this to "Frustrations of Amateur Radio". That was until we heard something weird on-air. All setup shenanigans forgotten, we marvelled at the experience. I was playing around on the 10m band, trying to hear people making noise and potentially our first contact for the field day we were participating in, when I heard something odd. Two stations talking to each other, but the audio was strange. It was like they were doubling up, the same audio played a fraction of a second later, until that moment, something I've only ever heard in a radio studio whilst editing using a reel-to-reel tape machine with separate recording and playback heads. Having just started using a digital only radio, at first I thought this was an artefact of the radio. I took

Foundations of Amateur Radio Recently I received a question in relation to the Bald Yak project. If you're not familiar, "The Bald Yak project aims to create a modular, bidirectional and distributed signal processing and control system that leverages GNU Radio." I know that I've said that several times now and I suspect I'm going to say it several more times before we're done. I was asked about a specific radio and if this project could make it use a frequency that the supplied software didn't cover. The answer is deceptively simple and if you know me at all, you know what's coming: "It depends". As with many things, what it depends on is not fixed. I'll come back to the question, but I'm making a diversion past a magical place, the local hardware store. You can buy everything you need to build a house with the caveat that some assembly is required. GNU Radio is similar for building a signal processing system, but, wait for it, some assembly is required. In the context of GNU Radio this means that you'll

Foundations of Amateur Radio Recently I made a joke about operating your station with a dummy load in response to John VA3KOT operating their station with the craziest antenna they ever used. It got me thinking about the ubiquitous "dummy load" as an antenna. Since becoming licensed I've spoken with several amateurs who tell a similar story, one comes to mind immediately, Lance VK6LR, now SK, who told me that they managed an unexpected 2m contact with another station using a dummy load, across the city. There's various versions of this doing the rounds, incandescent light bulbs used as both dummy load and antenna, coiled up roll of coax, everyone has a story to tell. Having spent several years proving that you can in fact use 10 mW and be heard on the other side of the planet, 13,945 km away, it tickled my fancy to think about what would happen if I replaced my antenna with a dummy load on purpose, as a test. For the past two or so months my WSPR beacon has been transmitting every ten minutes on the 15m

Foundations of Amateur Radio When you joined the global community of radio amateurs you did so with a perspective that represented, at the time, what you thought the hobby was and how it operated. Since then, years, months, even days ago, that perspective has shifted in both subtle and obvious ways. One of my local amateur radio clubs, Ham College, was specifically formed to provide amateur radio education and license exams. It's where I went to get my Foundation license in 2010 and it's where many of the local amateurs have been taught over the years. For years I've been semi-regularly visiting Ham College during their Foundation course sessions. The purpose of my visit is to share what it's like to be an amateur, what things you don't really know about before you get licensed, and what things to look out for when you are. In general I talk about how to find the rest of the community, what you can expect and what to do with your license once you pass the exam. I try to cover the highlights without overwh

Foundations of Amateur Radio Recently I received a lovely email from Michele IU4TBF asking some pertinent questions about the Bald Yak project. 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. The short answer to how I'm doing getting GNU Radio to play nice with my computer is that I have bruises on my forehead from banging my head against the wall. When I get to success I'll document it. To be clear, I'm not sure what the root cause is. I suspect it lies between the GNU Radio developers, the people making packages and the manufacturer of my computer. I'm the lucky one stuck in the middle. A more interesting question that Michele asked was, for Bald Yak, what is the A/D and D/A requirement for making GNU Radio talk to an antenna? This is a much deeper question that meets the eye and I think it serves as a way to discuss what I think that this project looks like. Ultimately in the digital realm

Foundations of Amateur Radio Have you ever come across a solution to a problem that you sort of knew you had, but didn't really appreciate until that moment? I had one of those recently. To set the scene, fair warning, we're not going to solve this today, we're still very much shaving yaks, but there's plenty to take away. So, the scene. I'm hosting my weekly net. It's going well. All the internet links are up and running again, thanks to the hard work behind the scenes of several unsung heroes, I can name a few, Bob VK6ZGN, John VK6RX and Rob VK6LD, but there are plenty of others whom I don't know and who have yet to stick up their hand to say, I was there. Regardless, thank you. Anyway, I'm hosting my weekly net, F-troop. A curious thing is occurring. Two of the stations are emitting a tone during their transmission. I'm pretty hot on how things sound, so I ask. We talk about it for a bit when Allen VK6XL comes in and tells us that according to his spectrum analyser it's a 1 kHz tone with harmonics and

Foundations of Amateur Radio Recently I built a first attempt at a noise cancelling circuit, on my couch, in GNU Radio, without holding a soldering iron and running the risk of the room smelling like burnt chicken, because if you believe the Internet, sometimes holding a hot piece of metal by the hot end is not the best way. The idea behind the circuit, or more accurately, flowgraph, is that you take a signal from two sources, invert one, combine them, and they cancel each other out. If the signal with the noise only contains noise, then you can, at least theoretically, remove the noise from the actual signal. Before you think that I'm inventing something new, I'm not. I'm merely attempting to recreate the same notion I came across decades ago, where you combine the signals from two microphones, preferably identical, reversing the wiring in one and talking into a microphone whilst holding the other one away from your mouth. I did essentially the same thing using RF signals from two RTL-SDR dongles. Randa

Foundations of Amateur Radio As you might recall, recently I stumbled on an excellent list of 52 weekly challenges put together by Fabian, DJ5CW and friends. You can find it at hamchallenge.org. As I've previously mentioned, it contains activities right across the amateur spectrum, from designing a QSL card to making a contact on 80m or 160m, with everything in between. It's an excellent tool to set a weekly goal to achieve and I recommend that you have a go. It's not the only interesting tool around. Amal VU3FTH and Steph Piper, whom you might know as MakerQueen AU, have put together an "Amateur Radio Skill Tree". It's a collection of hexagonal tiles, each with a skill, displayed together in an attempt to track what you know and could know about amateur radio. The idea is that you print it out and colour in each tile as you complete it. You'll find things like "Explore D-Star", "Build a cw key", "Teach a friend about Amateur Radio", and plenty more. Can you get four activities in a row and which skills co

Foundations of Amateur Radio The other day I was sitting on the couch lounging about when I came up with an idea and there and then I picked up a circuit board, soldered down a hundred or so components and built a noise cancelling gadget, all within about an hour .. right there, on my couch. Yeah, that didn't happen, least of all, my soldering skills are not up to scratch, never mind the couch. I did however build a noise cancelling circuit, on my couch, in about an hour, but no soldering iron was hurt and the room didn't smell of chicken afterwards. Instead I used GNU Radio to put together a series of blocks that allow me to apply noise cancelling to a signal. How does this work? Well, imagine a signal mixed together with the negative version of that signal, think of it as swapping positive and negative if you like. If you mix two identical signals together, one of them inverted, you end up with nothing, because they cancel each other out, where one is high, the other is opposite and low and vice versa.

Foundations of Amateur Radio For quite some time I have operated a WSPR or Weak Signal Propagation Reporter beacon on the 10m band. If you're not familiar with it, I've dialled the power right down to 10 dBm, or 10 milliwatts. You'd think that this would be a fool's errand, but it was heard 13,945 kilometres away. Of late the reports have been far and few between, despite the 10m band being quite active. Encouraged by a friend playing on 15m, I made the decision to change bands. At the moment this is not a trivial process, though at some point in the not too distant future, hopefully before I need a Zimmer Frame, I intend to erect a multi-band Hustler 6-BTV antenna that has been in storage for several years. Before that occurs, since it involves all kinds of shenanigans, I went for a simpler option, replace the 40m helical whip antenna with a 15m helical whip, something I can do without climbing on the roof. In case you're wondering, using an SG-237 antenna coupler, the 40m antenna tunes fine on 10m, but n

Foundations of Amateur Radio The other day I noticed a flurry of QSL card designs come across my screen and it sparked me into action on actually creating such a card for myself. I've previously talked about what I think of the current offerings in terms of validating contacts, but having a QSL card design is step one of confirming a contact, well, technically step two, since you have to make the contact first. I'm intending to use SVG as the design platform, since it's a text file that describes an image, so I can use my favourite command line tools, like "grep", "sed", "cut" and "awk" to replace parts of the file, so I can make a personal card for every contact, but that's a story for another day. Accompanying the rush of new card designs was an intriguing hash tag, #hamchallenge. Looking into this further I discovered a project by Fabian DJ5CW with an accompanying website, hamchallenge.org. When you go there, and you should, you'll discover 52 challenges with varying levels of difficulty that you can us

Foundations of Amateur Radio Life is messy. This is not a revelation. We attempt to organise this chaos by using all kinds of magic incantations, to-do lists, new year resolutions, plans, projects and anything else you might have in your arsenal. The same chaos reigns, in how we make progress. Some days are harder than others. I'm mentioning this because I've seen a couple of amateurs share all the things they didn't achieve last year. If we used that metric, I could point out that I didn't win the lotto, likely, neither did you, or your friends. I didn't get on HF to make a contact, I didn't put up a 6BTV antenna, the list is never ending. In other words, it's easy to say what you didn't do. What if you turned this upside down? I hosted my weekly radio net for its thirteenth year, I had my beacon heard more times than I have bandwidth available to check right now, I started a project that looks like it's going to keep me busy for some time to come. I've been working my way through a full system crash and I

Foundations of Amateur Radio As you might know, a little while ago I started a new project. "The Bald Yak project aims to create a modular, bidirectional and distributed signal processing and control system that leverages GNU Radio." In embarking on this adventure I've been absorbing information as I go whilst explaining what I've learnt to anyone who will sit still long enough. Credit to Glynn VK6PAW and Charles NK8O for their patience. For most people, me included, the introduction to GNU Radio happens via a graphical user interface where you build so-called flowgraphs. These are made up of little blocks that you wire together to get from a Source, where a signal originates, to a Sink, where it terminates. Each of these blocks does something to the signal, it might be a filter, an amplifier, it might encode or decode a signal like FM, AM, Wideband FM, or some other modulation like Phase Modulation or OFDM, Orthogonal Frequency Division Multiplexing, a way of transmitting digital information using mult