Foundations of Amateur Radio

Foundations of Amateur Radio The hobby of amateur radio is about communication. When you go on-air and make noise, you initiate a communications channel, sending information out into the world and hoping for another station to receive and decode what you sent. The channel itself can be used in an infinite number of ways and each one is called a modulation mode, or mode for short. The popular ones come with most radios, CW, AM, SSB and FM. Those few are not the only ones available. In fact as computers are being integrated into the radio at an increasing pace, signal processing is becoming part and parcel of the definition of a mode and new modes are being introduced at break neck speed. I've talked about WSPR as an example of one such mode, but there are many, each with their own particular take on how to get information between two stations. As you listen on the bands you'll increasingly find yourself hearing a bewildering litany of beeps, pops and clicks. Some of those are due to ionospheric conditions, but many are different modes that are being experimented with across our spectrum. If you have access to a band scope, a way of visualising radio spectrum, you can actually see the shapes and patterns of such signals over time and getting to that point can be as easy as feeding your radio audio into your computer and launching a copy of fldigi or WSJT-X. Every mode requires a specific tool to decode it and with practice you'll discover that there is often a particular look or sound associated with a mode. Over time you'll confidently select the correct decoder, using your brain for the process of signal identification. Of course if you don't have access to the library in your brain yet, since you've only just started, or if the mode you've come across is new, you'll need another library to discover what you found. There is such a library, the Signal Identification Wiki. It's a web-site that hosts a list of submitted signals, grouped by usage type, including one for our community. On the amateur radio page of the Signal Identification Wiki there are over 70 different modes listed, complete with a description, an audio file and a spectrogram. With that you can begin to match what you've discovered on your radio to what the web-site has in the library and determine if you can decode the incoming information. I will mention at this point that the Signal Identification Wiki is far from complete. For example, the Olivia mode has 40 so-called sub-modes of which about 8 are in common use. Each of those sub-modes looks and sounds different. The wiki shows only a single line for Olivia. I'm pointing this out because the wiki allows you to submit a mode for others to use. If you have a signal, either by recording it off-air, or better still, recording it directly from the source, consider submitting it to the wiki so others can benefit from your experience. If you've come across a signal and you cannot figure out what it is, there are other places you can go for help. The four and a half thousand members of the /r/signalidentification sub on reddit will happily look at and listen to your signal and try to help. Make sure you contribute some meta data like the time, frequency and location to accompany the spectrogram and audio. You might have come to this point wondering why I'm encouraging you to use and contribute to the wiki and ask for help on reddit. Amateur radio is about experimentation. We love to do that and as we make signal processing easier and easier, more people are making new modes to play with. The speed at which this is happening is increasing and as an operator you can expect to come across new signals. I remember not that long ago, it was last month, tuning to an FT8 frequency and the person I was with asking what that sound was. They'd heard it before but never discovered its purpose, even though FT8 has been with us since the 29th of June 2017. What interesting signals have you come across and how did you go with decoding them? I'm Onno VK6FLAB

Foundations of Amateur Radio Recently I received a lovely email from Simon G0EIY, who reminded me that there is a voice-keyer that fits into a microphone. It was designed by Olli DH8BQA as a replacement for a standard Yaesu MH-31 microphone. I'd come across this a while ago and for several reasons put off actually ordering one, but Simon's encouragement tipped me over the fence and I've placed my order. What I'm expecting to arrive at some point is a kit that has the minuscule surface mount components already soldered to a circuit board, leaving a couple of individual components ready for my soldering iron abuse. I'll let you know how it goes. This little experience reminded me that I've been stumbling across solutions like this for years, an amateur with an itch to scratch and the drive to do something about it. For example, Paul KE0PBR likes to operate satellites and in doing so amassed a collection of frequencies. Since the Doppler effect alters the actual frequency depending on the satellite coming towards you or moving away from you, there are corrections that need to be done. If you're in the field, this is something that you might struggle with, so Paul created a Frequency Cheat Sheet. If you're looking into magnetic loop antennas, you'll quickly encounter a spreadsheet made by Steve AA5TB that will get you started with the parameters for designing and building your own magnetic loop. The popular VK Contest Logger, known colloquially as VKCL was built by Mike VK3AVV. It's a simple to use logging tool that has a large collection of rules for different contests and Mike often brings out a new version to incorporate the latest rule changes just before a contest. It even incorporates a station log. If you've come across apps like DroidPSK, DroidSSTV and DroidRTTY, they're the brain children of Wolfgang W8DA. The increasingly popular Repeaterbook maintained by a global community of volunteers is the work of Garrett KD6KPC. I've lost count of the number of radio amateurs running an online shop where you can buy gear, or kits, or circuit boards, components, antennas, software and the like, not to mention an astonishing collection of professionally built tools like antenna analysers, filters, amplifiers and more. It's said that amateurs are notorious for their short arms and deep pockets. I like to think of it as a discerning and informed customer. It's easy to sell snake-oil to the masses, it's been going on for centuries, it's much harder to do that when the person you're selling to knows how the thing you're selling works and knows how to read a data-sheet, let alone ask awkward questions when the need arises. Before I go on I will mention that the people I've named here are unaware of me doing so. I've not been approached by any of them to mention their name and I have no relationship, other than being a happy customer. I'm saying this out loud because this podcast goes out on amateur radio repeaters all over the world and commercial use of amateur radio is strictly prohibited. You might have gotten to this point wondering why I'm even taking the time to highlight some of the efforts I've come across and the reason is very simple. This activity is everywhere, you just have to look. It's not like Olli, Paul, Steve, Mike, Garrett or Wolfgang shouted their involvement from the rooftops, it's just that the information is available if you care to look. Remember, these people are radio amateurs just like you and I. That's important because the difference between a tool that you're using that you built, sitting in your shack or on your computer and that of the people I've named is that they took an extra step and shared their efforts with the community. Some amateurs are making a living from this hobby and I applaud their efforts, for the rest of us, me included, that's often not the point. Invention is happening all over the world, right now. You are doing it, despite your protestations to the contrary. You might have made a PDF that you carry around during a contest, or it might be a calculator you knocked up to figure out how to build something. It might be a circuit diagram, an app, a how to guide, a map or a video. All of these things are creations that can be shared to increase the amount of innovation that happens by people bouncing ideas off other ideas. In 1675, Sir Isaac Newton said: "If I have seen further it is by standing on the shoulders of Giants." You are one of those giants and the person who uses your contribution to make their own is standing on your shoulders. What are you waiting for? Publish, share, document, photograph and make available, it's how society makes progress and it's how amateur radio stays at the forefront of innovation. Get on air and make noise is not purely restricted to the RF spectrum. I'm Onno VK6FLAB

Foundations of Amateur Radio Sometimes when you head into uncharted territory, you gotta laugh at yourself from time to time. Last weekend I participated in a contest, something I enjoy doing as you might recall. To simplify the process of setting up in a vehicle I'd proposed a bold plan to save space and reduce complexity. I was anxious about reducing the amount of technology because I'd come up with a plan to use a paper log to track my contest contacts. I had visions of operating for the best part of 24 hours and making hundreds of contacts. This was based on the fact that in 2016 I'd done this same contest on my own and made a 138 contacts and scored 18221 points, having moved 17 times. I'd also done the contest in 2018 and for reasons I don't recall, I made one contact over 8 hours. That right there should have been a warning sign that I might not quite get the result I'd been fearful of. Blissfully unaware of the adventure that was unfolding, after driving to the first location, I called CQ for the better part of an hour. Then I called some more. When I was done with that, I called CQ more. 90 minutes in, I made my first contact. That pretty much set the pattern for the next nine hours. At one point we feared that the radio had packed up, but then I made a 2900 km contact with the other side of the country between me in Perth in VK6 and Catherine VK7GH in Tasmania. Around five pm we packed up, having moved location six times, making eight contacts and claiming 64 points, having worked three of the six states I heard. Talk about overblown fears. Looking back, even documenting 138 contacts on paper doesn't seem nearly as daunting after the fact, but that's for another day. I did learn some other things too. I was worried about logging the band correctly, since using a computer that's not connected to the radio requires an extra step when you change band. Using paper the issue wasn't the band, it was remembering to record the time. We didn't have the opportunity to test all the gear before the contest. I was bringing in some extra audio splitters, which didn't work with the set-up we had, testing before hand would have revealed that. We knew that there was a risk associated with not testing before and decided that in the scheme of things it didn't matter and we were right. It didn't. We hadn't much planned for food and pit-stops, but having a GPS and an internet connection solved all those issues almost invisibly. Of course that wouldn't work in an unpopulated area, but we were well inside the metropolitan area of a big city, well, Perth. Using a head-set worked great, though it didn't have a monitoring feature, so my voice got louder and louder and Thomas VK6VCR who took on the tasks of navigating and driving became deafer and deafer as the day progressed. I keep coming back to wanting a portable voice-keyer, a device that you can record your CQ call into and then at the press of a button, play it back so you don't lose your voice whilst calling CQ hour after hour. The challenge seems to be that you need to find a way to incorporate it into the existing audio chain so it doesn't introduce interference. Winning a contest requires contacts and that can only happen if there are other participants. This time around there didn't seem to be that many on air making noise. I think I heard a grand total of 13 stations. Some of that was due to propagation conditions which were nothing like I've ever heard before, but perhaps if I stick around for another solar cycle, that too will become familiar. Atrocious is one word that comes to mind. Continuing our learning, the weather, not just space-weather, actual earth weather, snow, rain, hail and in our case sun. Neither of us thought to bring a hat since the forecast was for intermittent rain. We had no rain, instead had the opportunity to bask in the winter sun. Yes, it's winter here in Oz when it's Summer in Europe. As it happens, our winter temperatures are like your summer ones, but I'll leave it to you to confirm that for yourself. Finally, we have a local phenomenon in VK6. When the sun goes down, the 40m band comes alive with the sounds of Indonesia. Among the radio amateurs are plenty of pirate stations with massive AM transmitters enjoying the conditions, chatting, chanting and what ever else comes to voice. Not conductive to being on-air and making noise, but as far as I can tell, not commonly heard outside of VK6. That said, the Indonesian radio amateur community must have the patience of saints putting up with the interference that their non-licensed countrymen cause on a daily basis. My hat off to you! As I've said all along, this radio thing is about getting on air and having fun and I can tell you, we did. What did you get up to? I'm Onno VK6FLAB

Foundations of Amateur Radio My first ever interaction with amateur radio was a field day on Boterhuiseiland near Leiden in the Netherlands when I was about twelve. The station was set-up in an army tent and the setting was Jamboree On The Air, or JOTA. My second field-day, a decade ago, was a visit to a local club set-up in the bush. At that point I already had my licence and I'd just started taking the first baby steps in what so-far has been a decade long journey of discovery into this amazing hobby. A field day is really an excuse to build a portable station away from the shack and call CQ. A decade on, I vividly remember one member, Marty, now VK6RC, calling CQ DX and getting responses back from all over the world. From that day on I looked for any opportunity to get on air and make noise. Often that's something I do in the form of a contest. I love this as a way of making contacts because each interaction is short and sweet, there's lots of stations playing from all over the planet and each contest has rules and scores. As a result you can compare your activity with others and look back at your previous efforts to see if you improved or not. As you've heard me repeatedly say, I like to learn from each activity and see if there are things I could have done differently. I tend to think of this as a cycle of continuous improvement. A few months ago a friend asked me if I was interested in doing a contest with him. For me that was a simple question to answer, YES, of course! Over the last few months we've been talking about how we'd like to do this and what we'd like to accomplish. For example, for me there's been a regular dissatisfaction that during portable logging I've made mistakes with recording the band correctly in the log and having to manually go back and fix this, taking away from making contacts and having fun. To prevent that, I wanted to make sure that we had electronic logging that was linked to the radio in the same way as I do in my shack, so it didn't happen again. It was a small improvement, but I felt it was important. Doing this meant that we'd either need to sort out a computer link, known as CAT, or Computer Assisted Tuning for his radio in the vehicle, or bring my radio, CAT control, power adaptors as well as bring a laptop, power supply and last but not least find space in the vehicle to mount all this so it would work ergonomically for a 24 hour mobile contest. The vehicle in question is the pride and joy of Thomas VK6VCR, a twenty-odd year old Toyota Land Cruiser Ute with two seats, three if you count the middle of the bench, and neither of us would ever be described as petite, so space is strictly limited. In playing this out and trying to determine what needed to go where, we discovered that this wasn't going to work and I made the bold proposal to go old school and use a paper log. This would mean that we could use the existing radio, without needing to sort out CAT control, the need for any power adaptors, no space required for a laptop, no power for that, no extra wiring in the vehicle, and a whole lot more simplicity. So that's what we're doing, paper log and a headlamp to be able to see in the dark. I must confess that I'm apprehensive of this whole caper, but I keep reminding myself that this too is an experience, good or bad, and at the end of the day, we're here to have fun. I might learn that this was the worst idea I've ever had, or I might learn that this works great. It's not the first time I've used a paper-log, so I'm aware of plenty of pitfalls, not the least of which is deciphering my own handwriting, the ingenuous project of three, or was it four, different handwriting systems taught to me by subsequent teachers in different countries. There's the logistics of being able to read and write at an odd distance, trying to work out how to operate the microphone with the wrong hand, though we are trialling a headset and boom microphone with a push to talk button, and then there's the radio, one I've used before, but not in a contest setting and not whilst driving around on the seat of a 4WD hell-bent on rattling my teeth from their sockets. On the plus side, I've done a contest with my friend before and he is familiar with my competitive streak and we're both up for a laugh, so I'm confident that despite the challenges that lie ahead, we're going to make fun and enjoy the adventure. I can't wait to find out if simplifying things will result in a better experience and only trying it will tell. I'll let you know how it goes. When was the last time you stepped out of your comfort zone and what did you do? How did it work out? I'm Onno VK6FLAB

Foundations of Amateur Radio Recently a budding new amateur asked the question: "What radio should I buy?" It's a common question, one I asked a decade ago. Over the years I've made several attempts at answering this innocent introduction into our community and as I've said before, the answer is simple but unhelpful. "It depends." Rather than explaining the various things it depends on, I'm going to attempt a different approach and in no particular order ask you some things to consider and answer for yourself in your journey towards an answer that is tailored specifically to your situation. "What's your budget?" How much money you have set aside for this experiment is a great start. In addition to training and license costs, you'll need to consider things like shipping, import duties and insurance, power leads and a power supply, coax leads and connectors and last but not least, adaptors, antennas and accessories. "Should you buy second hand or pre-loved?" If you have electronics experience that you can use to fix a problem with your new to you toy this is absolutely an option. When you're looking around, check the provenance associated with the equipment and avoid something randomly offered online with sketchy photos and limited information. Equipment is expensive. Check for stolen gear and unscrupulous sellers. "What do you want to do?" This hobby is vast. You can experiment with activities, locations, modes and propagation to name a few. If you're looking at a specific project, consider the needs for the accompanying equipment like a computer if what you want to explore requires that. You can look for the annual Amateur Radio Survey by Dustin N8RMA to read what others are doing. "What frequencies do you want to play on?" If you have lots of outdoor space you'll have many options to build antennas from anything that radiates, but if you're subject to restrictions because of where you live, you'll need to take those into account. You can also operate portable, in a car or on a hill, so you have plenty of options to get away from needing a station at home. "Are there other amateurs around you?" If you're within line of sight of other amateurs or a local repeater, then you should consider if you can start there. If that doesn't work, consider using HF or explore space communications. There are online tools to discover repeaters and local amateurs. "Is there a club you can connect to?" Amateur radio clubs are scattered far and wide across the planet and it's likely that there's one not too far from you. That said, there are plenty of clubs that interact with their members remotely. Some even offer remote access to the club radio shack using the internet. "Have you looked for communities to connect with?" There is plenty of amateur activity across the spectrum of social media, dedicated sites, discussion groups, email lists and chat groups. You can listen to podcasts, watch videos, read eBooks and if all that fails, your local library will have books about the fundamental aspects of our hobby. "Have you considered what you can do before spending money?" Figuring out the answers to many of these questions requires that you are somewhat familiar with your own needs. You need a radio to become an amateur, but you need to be an amateur to choose a radio. To get started, you don't need a radio. If you already have a license you can use tools like Echolink with a computer or a mobile phone. If you don't yet have a license, you can listen to online services like WebSDR, KiwiSDR and plenty of others. You can start receiving using a cheap RTL-SDR dongle and some wire. "Which brand should you get?" Rob NC0B has been testing radios for longer than I've been an amateur. His Sherwood testing table contains test results for 151 devices. The top three, Icom, Kenwood and Yaesu count for more than half of those results. This means that you'll likely find more information, more support and more local familiarity with those three. I will point out that Rob's list has 27 different brands on it, so look around and read reviews both by people who test the gear and those who use it. And finally, "Why are you here?" It's a serious question. Different things draw different people into this community. Think about what you like about it and what you want to do more of. Take those things into consideration when you select your radio. As you explore the answers to these questions, you'll start building a picture of what amateur radio means to you and with that will come the answer to the question: "What radio should I buy as my first one?" If there are other questions you'd like to ask, don't hesitate to get in touch. My address is [email protected]. I look forward to hearing from you. I'm Onno VK6FLAB

Foundations of Amateur Radio One of the questions you're faced with when you start your amateur journey is around connectors. You quickly discover that every piece of equipment with an RF socket has a different one fit for purpose for that particular device. That purpose includes the frequency range of the device, but also things like water ingress, number of mating cycles, power levels, size, cost and more. As an aside, the number of mating cycles, how often you connect and disconnect something is determined by several factors, including the type of connection, manufacturing precision and the thickness of the plating. That said, even a so-called low cycle count connector, like say an SMA connector lasting 500 cycles will work just fine for the next 40 years if you only connect it once a month. Back to variety. My PlutoSDR has SMA connectors on it as do my band pass filters, my handheld and one RTL-SDR dongle. The other dongle uses MCX. Both my antenna analyser and UHF antenna have an N-type connector which is the case for my Yaesu radio that also has an extra SO239 which is what my coax switches have. My HF antenna comes into the shack as an F-type and nothing I currently own has BNC, but stuff I've previously played with, does. When you go out on a field-day, you mix and match your gear with that of your friends, introducing more connectors and combinations. Invariably you acquire a collection of adaptors. At first this might be only a couple, quickly growing to a handful, but after a while you're likely to have dozens or more. My collection, a decade's worth, which currently includes more than 25 different combinations is over a hundred individual adaptors and growing. For most of the time these have been tossed into a little tool box with a transparent lid, but more and more as the collection and variety grew I started to realise that I was unable to quickly locate an adaptor that I was sure I had, since it had been used in a different situation previously. In addition to coming to the realisation that the reason I couldn't find a connector was because it was still in use, I began to notice that I had daisy chains of connectors. For example, my HF antenna has a PL259 connector that is adapted to an F-type connector with an SO239 barrel, a PL259 to BNC and a BNC to F-type adaptor. At the other end of the RG6 coax that runs from outside into the shack, the reverse happens, F-type to BNC and BNC to PL259. If you're counting along, that's five adaptors to get from PL259 to PL259 via F-type. At this point you might wonder why I'm using RG6 coax. The short answer is that I have several rolls of it, left over from my days as an installer for broadband satellite internet. RG6 is very low loss, robust and heavily shielded. Although it's 75 Ohm - a whole other discussion - in practice that's not an issue. What is a problem is that the only connectors available for it are F-type compression connectors. To get those to PL259 requires a step sideways via BNC. My point is that the number of adaptors is increasing by the day. I should acknowledge the existence of so-called universal connector kits. The idea being that you go from one connector to a universal joiner and from that to another connector. Generally these kits have around 30 connections, giving you plenty of options, but in reality more often than not, you only have half a dozen universal joiners, so your money is effectively buying you half a dozen conversions, great for a field day, not so great for a permanent installation. You could build your own collection and use something like SMA or BNC as your universal joiner, which is something I'm exploring. To keep track of my collection, recently I started a spreadsheet. It's essentially a list showing the number and types of connections. If you make a pivot table from that you'll end up with a grid showing totals of adaptors you have. You can use this grid to fill a set of fishing tackle boxes and all of a sudden you've got a system where everything has its own place. If you start this process you'll quickly notice that the table only needs to be half filled, since a BNC to SMA is the same as an SMA to BNC adaptor. This leaves you space to do some fancy footwork where the bottom right hand of the triangle can fit into the top left of the empty space, but I'll leave you to figure that out. My table also includes things like TNC and MCX adaptors, but I don't use those very often, so at the moment I'm putting them in their own box together with T-adaptors and other weird and wonderful things like FME and reverse SMA. For setting the order, I've gone for alphabetic, but if you have a better suggestion, I'm all ears. My email address as always is [email protected]. What ideas have you come up with to organise the chaos that is your sprawling connector library? I'm Onno VK6FLAB

Foundations of Amateur Radio A while ago as part of my ongoing exploration into all things radio I came across a utility called rtlsdr-airband. It's a tool that uses a cheap software defined radio dongle to listen to a station frequency or channel and send it to a variety of different outputs. Originally written by Tony Wong in 2014, it's since been updated and is now maintained by Tomasz Lemiech. There are contributions by a dozen other developers. The original examples are based around listening to Air Traffic Control channels. I know of a local amateur who uses it to listen to and share the local emergency services communication channels, especially important during local bush fires. While sophisticated, it's a pretty simple tool to use, runs on a Raspberry Pi, or in my case, inside a Docker container. It's well documented, has instructions on how to compile it and how to configure it. Before I get into what I've done, as a test, let's have a look at the kinds of things that rtlsdr-airband can do. First of all, it's intended to be used for AM, but if you read the fine documentation, you'll learn that you can also make it support Narrowband FM. It can generate output in a variety of different ways, from a normal audio file, to an I/Q file - more about that at another time, and it can also send audio as a stream to a service like icecast, broadcastify or even to your local pulse audio server. If that last one doesn't mean much to you, it's a local network audio service, popular under Linux, but it runs on pretty much anything else thanks to the community efforts of many. So, on the face of it, you can listen to a channel, be it AM or Narrowband FM, and send that to some output, but I wouldn't spend anywhere as much time on this if that was all there was to it. The software can also dynamically change channels, support multiple dongles, or simultaneously listen to several channels at once and output each of those where ever you desire. Another interesting thing and ultimately the reason I thought to discuss it here is that rtlsdr-airband also supports the concept of a mixer. You can send multiple channels to a single mixer and output the result somewhere else. Using a mixer, in addition to setting cut off frequencies and other audio attributes, you can set the audio balance for each individual channel. This means that you can mix a channel exclusively to the left ear, or to the right ear, to both, or somewhere in between. Now, to add one extra little bit of information. In my location there's about a dozen or so amateur repeaters most of which can be heard at some time or another from my QTH. The frequency spread of those dozen repeaters is less than 2 MHz. A cheap RTL-SDR dongle can handle about 2.56 MHz. Perhaps you've not yet had the ah-ha moment, but what if you were to define an rtlsdr-airband receiver that listened to a dozen amateur radio repeaters - at the same time - and using the audio balance spread those repeaters between your left and right ear, you could stream that somewhere and listen to it. I'm sitting here with my headphones on, listening to the various repeaters do their idents, various discussions on different repeaters, a local beacon, incoming AllStar and other links, all spread out across my audio horizon, almost as if you can see where they are on the escarpment, though truth be told, I've just spaced them out evenly, but you get the idea. My original Raspberry Pi wasn't quite powerful enough to do this in the brute force way I've configured this, so as a proof of concept I'm running it on my main computer, but there's nothing to suggest that doing a little diligent tweaking won't make my Pi more than enough to make this happen. As for audio bandwidth, it's a single audio stream, so a dial-up connection to the internet should be sufficient to get the audio out to the world. I will point out that there may be legal implications with streaming your local amateur repeaters to the world, so don't do that without checking. For my efforts, this is an example of: "I wonder if ..." As it turns out, Yes you can. As it happens, my next challenge is to use this code on a PlutoSDR where the bandwidth is slightly larger, mind you, I'll have to do some fancy footwork to process the data without overwhelming the CPU, but that's another experiment in my future. What kind of crazy stuff have you tried that worked? I'm Onno VK6FLAB

Foundations of Amateur Radio The activity of amateur radio revolves around experimentation. For over a century the amateur community has designed, sourced, scrounged and built experiments. Big or small, working or not, each of these is an expression of creativity, problem solving and experimentation. For most of the century that activity was accompanied by the heady smell of solder smoke. It still makes an appearance in many shacks and field stations today, even my own, coaxed by an unsteady hand, more and more light and bigger and bigger magnification, I manage to join bits of wire, attach components and attempt to keep my fingers from getting burnt and solder from landing on the floor. I've been soldering since I was nine or so. I think it started with a Morse key, a battery and a bicycle light with a wire running between my bedroom and the bedroom of my next door neighbour. In the decades since I've slightly improved my skill, but I have to confess, soldering isn't really my thing. My thing is computers. It was computers from the day I was introduced in 1983 and nothing much has changed. For reasons I don't yet grasp, I just get what computers are about. They're user friendly, just picky whom they make friends with. When I joined the amateur community, it was to discover a hobby that was vast beyond my wildest imagination, technical beyond my understanding and it was not computing. Little did I know. Computing in amateur radio isn't a new thing. For example, packet radio was being experimented with in 1978 by members of the Montreal Amateur Radio Club, after having been granted permission by the Canadian government. In 2010 when I came along we had logging, DX-clusters and the first weak signal modes were already almost a decade old. Software Defined Radio has an even longer history. The first "digital receiver" came along in 1970 and the first software transceiver was implemented in 1988. The term "software defined radio" itself was 15 years old when I joined the hobby and truth be told, it's a fascinating tale, I'll take a look at that at another time. When I started my amateur journey like every new licensee, I jumped in the deep end and kept swimming. From buying a radio, to discovering and building antennas, from going mobile to doing contests and putting together my home station, all of it done, one step at a time, one progressive experiment after another, significant to me, but hardly world shattering in the scheme of things. Now that I've been here for a decade I've come to see that my current experiments, mostly software based, are in exactly the same spirit as the circuit builders and scroungers, except that I'm doing this by flipping bits, changing configurations, writing software and solving problems that bear no relation to selecting the correct combination of capacitance and reactance to insert into a circuit just so. Instead I'm wrestling with compilers, designing virtual machines, sending packets, debugging serial ports and finding new and innovative ways to excite transceivers. For example, today I spent most of the day attempting to discover why when I generate a WSPR signal in one program, it cannot be decoded by another. If that sounds familiar, that was what I was doing last week too. This time I went back to basics and found tools inside the source code of WSJT-X and started experimenting. I'm still digging. As an aside I was asked recently why I want to do this with audio files and the short answer is: Little Steps. I can play an audio file through my Yaesu FT-857d. I can receive that and decode it. That's where I want to start with my PlutoSDR experiments, so when I'm doing this, I can use the same audio file and know that the information can be decoded and that any failure to do so is related to how I'm transmitting it. Back to soldering irons and software. In my experience as an amateur it's becoming increasingly clear that they're both the same thing, tools for experimentation, with or without burning your fingers. I'm Onno VK6FLAB

Foundations of Amateur Radio As you might recall, I took delivery of a device called a PlutoSDR some time ago. If you're not familiar, it's a single-board computer that has the ability to transmit and receive between 70 MHz and 6 GHz. The system is intended as a learning platform, it's open source, you get access to the firmware, compilers and a whole load of other interesting tools. I used it to play with aviation receive using a tool called dump1090 which I updated to use Open Street Map. If you're interested, it's on my VK6FLAB github page. Over the past few months I've been steadily acquiring little bits and pieces which today added up to a new project. Can I use my PlutoSDR to transmit WSPR? This all started because of an experiment and a conversation. The experiment was: "Using my FT-857d on 70cm can I transmit a weak signal mode like WSPR and have my friend on the other side of the city decode the transmission?" The answer to that was a qualified "Yes". I say qualified, since we weren't able to transmit a WSPR message, but using FT8 we were happily getting decodes across the city. We're not yet sure what the cause of this difference is, other than the possibility that the combined frequency instability at both ends was large enough to cause an issue for a WSPR message, which lasts about two minutes. On the other hand, I learned that my radio can in fact go down to 2 Watts on 70cm. I've owned that radio for over a decade, never knew. Now that I have a band pass filter, some SMA leads and the ability to talk to my Pluto across the Wi-Fi network, I can resurrect my Pluto adventures and start experimenting. I mentioned that this was the result of an experiment and a conversation. The conversation was about how to create a WSPR signal in the first place. At the moment if you run WSJT-X the software will generate audio that gets transmitted via a radio. All fine, except if you don't have a screen or a mouse. Interestingly a WSPR transmission doesn't contain any time information. It is an encoded signal, containing your callsign, a maidenhead locator - that's a four or six character code representing a grid square on Earth, and a power level. That message doesn't change every time your transmitter starts the cycle, so if you were to create say an audio file with that information in it, you could just play the audio to the nearest transmitter, like a handheld radio, or in my case a Pluto, and as long as you started it at the right time, the decoding station wouldn't know the difference. As an aside, if you're playing along with your own Pluto, and far be it for me to tell you to go and get one, you can set the Pluto up using either USB, in which case it's tethered to your computer, or you can get yourself a USB to Ethernet adaptor and connect to it via your network. If you have a spare Wi-Fi client lying around, you can get that to connect to your Wi-Fi network, connect the Pluto via Ethernet to the Wi-Fi client and your gadget is connected wirelessly to your network. I can tell you that this works, I'm typing commands on the Pluto as we speak. As is the case in any experiment in amateur radio, you start with one thing and work your way through. At the moment I want to make this as simple as possible. By that I mean, as few moving parts as I can get away with. I could right now fire up some or other SDR tool like say GNU Radio and get it to do the work and make the transmission, but what I'd really like to do is actually have the Pluto do all the work, so I'm starting small. Step One is to create an audio file that I can transmit using the Pluto. It turns out that Step One isn't quite as simple as I'd hoped. I located a tool that actually purports to generate an audio file, but the file that it builds cannot be decoded, so there's still some work to be done. On the face of it the level of progress is low, but then this whole thing has been going for months. The experiment on 70cm lasted half an hour, the discussion took all of a cup of coffee. So far, I've spent more time on this project making the Wi-Fi client talk to my network than all the rest put together and that includes finding and ordering the Pluto in the first place. You might well wonder why I'm even bothering to talk about this as yet unfinished project. The reason is simple. Every day is a new one. Experiments are what make this hobby what it is and every little thing you learn adds to the next thing you do. Some days you make lots of progress, other days you learn another way to not make a light bulb. I'm Onno VK6FLAB

Foundations of Amateur Radio In my day job I work in computing. For many years that consisted of going on-site and fixing stuff. Invariably this involved me fixing servers that were installed into a room the size of a broom closet with an optional air conditioner screaming in my ear. The experience often included sitting on a crate, or the floor, holding a keyboard and if it was a Windows Server, rolling a mouse on my knee in order to click on stuff barely discernible on a tiny screen that likely sat a meter too high above my eye line with Ethernet wires going diagonally from one end of the room to the other. These days with ubiquitous internet connectivity that kind of experience is mostly a thing of the past. That said, operating a radio during a contest in many stations I've used over the years is not far from that kind of layout. Often a traditional shack starts off with a radio on a table with a notepad to record contacts. Over time that gets expanded with technology like a computer. It's common to have to juggle the radio display and keyboard, to find a spot for the mouse that doesn't interfere with the desk microphone, or to have to reach over to change band and to activate a different filter, select another antenna, use the rotator or some other essential tool that's required for making that elusive contact. Some stations have multiple monitors, sometimes they're even together, but more often than not they're a different size, sitting too high and the radio sits as a road-block between your eye line between the screen and the keyboard. I'm raising this because over the years I've not actually seen anyone spend any energy on discussing how you might improve this experience. If this was your workplace, the occupational health and safety police would be all over you and for good reason. You could argue that amateur radio is a hobby and that OH&S is of lesser concern, but to that I'd like to point out that you have the same risk of self injury at work as you do in your shack, especially if you're doing a contest for 24 or 48 hours. Not only is there a risk of injury, why make the experience harder than it needs to be? Ergonomics is the process of designing or arranging a workplace to fit the user. It's a deliberate process. You have to actually stop to consider how you are using a space, in this case your shack. At the moment I'm experimenting with different aspects of the layout of my shack. For example, I started with a layout of the computer, counter intuitive perhaps, since we're talking about a radio shack, but given that I'm spending much of my time doing contests and digital modes, the computer is used much more than the radio is, even if the radio is what's making all the on-air noise. After making sure that my keyboard, mouse and screen were in locations that actually helped me, I started trying to figure out where to put the radio and what role it actually plays in making the contact. If during a contest you're using search and pounce, which is when you hunt up and down the bands looking for a contact, you might argue that you'll need access to the radio to change frequency, but if you already have your computer connected to the radio, you can change frequency from the keyboard or by control with your mouse. Another way I'm looking on reducing the amount of stress to my body whilst operating my station is by sorting out audio. Almost every radio has a speaker on it, but if you've got more than one going at the same time it becomes really difficult to determine which one is actually making noise and even harder if multiple stations are on different frequencies on different radios at the same time. You could wear headphones and select a radio, one at a time, either by plugging in a particular radio, or by using a selector. If you're using digital modes, the audio might already be going into the computer, which offers you the ability to select from different sound cards, but there are other options. I'm working on plugging the audio from each radio into an audio mixer that will allow me to set the level for each radio independently, mute at will, set the tone, the balance between left and right ear and a few other things. For a microphone I plan on using the same mixer and I'm working on how to have my digital audio coming from the computer incorporated into the same audio environment, because the digital audio could just as easily be a voice caller using the same system. For push to talk I settled on a foot switch a couple of years ago. That said, if I'm on my own, I tend to use VOX, or voice operated switching, which turns on the transmitter when microphone audio is detected by the radio. This will need some careful planning if I'm going to connect multiple radios, since I don't want to transmit the same message across each radio at the same time, but with computer control, that too can be addressed. My point is that we have lots of technology available to us as radio amateurs to achieve what e

Foundations of Amateur Radio Have you ever taken a moment to consider the available bandwidth on the various amateur bands? As an entrant into amateur radio in Australia as a Foundation licence holder you have access to six different amateur bands, the 80m band, 40m, 15m, 10m, 2m and 70cm. If you add the bandwidth from each of those bands together, you end up with 26.65 MHz worth of bandwidth to play with in Australia. I can tell you that's a big chunk of bandwidth, but until I give you some context, 26.65 MHz isn't likely something that you can picture. You might think of things as being pretty crowded. For example, on the 40m band during a contest it's common to hear wall to wall signals. There's barely enough room to call CQ and not interfere with anyone else. But how crowded is it really? Let's start with an SSB signal, typically it's 2.4 kHz wide. On the 40m band, with 300 kHz of bandwidth, there's room for about 125 SSB signals side-by-side. On the 10m band, there's space for over 700 SSB signals side-by-side. Across all the available bandwidth for a Foundation license holder in Australia, there's room for over 11-thousand different SSB signals side-by-side. While we're on the subject of crowding, there's talk about the massive influx of FT8, some call it a scourge. FT8 channels are transmitted within a single SSB channel and each takes up 50 Hz. That means that within an SSB channel of 2.4 kHz, there's room for 48 different FT8 channels, and if you take into account the odd and even time-slots, that doubles to 96 different signals, all within the same single SSB channel. So while FT8 is popular and growing, let's not get too excited about how much space it's taking up. From the perspective of an Australian Foundation license holder, it's taking up exactly six separate SSB slots of those 11-thousand across the six available bands, room for 576 separate FT8 signals, taking up a total of 14.4 kHz, or 0.05% of the available bandwidth. Let's look at this another way, of the 26.65 MHz available bandwidth, 20 MHz is from the 70cm band alone, that means that all the other bands put together, fit inside the 70cm band three times over. Let that sink in for a moment, adding the 80m, 40m, 15m, 10m and 2m band together fit inside the 70cm band three times. You can use the 70cm band alone for 800-thousand FT8 signals, remember that there's two time slots, so you get two for one. If this makes your mind explode, then consider that a carrier wave signal is considered to be about 25 Hz wide, so on the 70cm band you could have 800-thousand individual CW signals. You could allocate a personal CW frequency to every one of the amateurs in the United States in the 70cm band and still have room for expansion, not that I'm advocating that, just to give you a sense of scale. I should note that the 70cm band in the United States is even larger than it is in Australia, but I don't want to get bogged down into the various band plans across the world at the moment. You might ask yourself why am I getting so excited about this? Amateur radio is about experimentation. I've been telling you about HF propagation and using techniques like FT8 to determine just how far your signal goes, but you could use the same techniques to build a 70cm communication network with the amateurs within your city and share information across the city, perhaps even build a mesh network using your 70cm hand-held and an FT8-call network. It could be used to distribute propagation information, or messages in case of an emergency, or form the basis of something completely different. If that doesn't whet your appetite, consider that the 1mm amateur band, which runs from 241 to 250 GHz is ready for you to experiment when your license permits. The current world distance record is 114 km, set in 2008 by Brian WA1ZMS and Peter W4WWQ, it has 9 GHz bandwidth and has room for 360-million FT8 signals, or 60 exclusive FT8 channels for every amateur on the planet. My point is that as radio amateurs we have access to a massive chunk of radio bandwidth and it's just sitting there waiting for you to experiment with. I'm Onno VK6FLAB

Foundations of Amateur Radio If you've been around radio amateurs for a little while you're likely to have heard about the Solar Cycle and that it affects radio propagation for HF or High Frequency, also known as shortwave communications. The frequencies in the range of around 3 to 30 MHz, or 100m to 10m wavelength. One of the main ways it's used is for is for long distance or global communication and one of the most common ways that's done is using the ionosphere around the globe to refract a radio signal. In September 2020, the Solar Cycle 25 Prediction Panel, announced that Solar Cycle 25 had commenced in December 2019 and radio amateurs around the globe rejoiced. The first question for me was, why Solar Cycle 25? You might think of the Sun as a stable light in the sky. As it happens, the bright light hides all manner of ferocious activity. One of the measures of this activity is the number of dots observed on the surface of our Star. These dots are called sunspots. As Solar activity increases, the number of sunspots increases. The activity is cyclical, it increases and decreases over time. Each increase and decrease combined is known as a Solar Cycle. On average a cycle lasts about 10.7 years. Simple maths gives you that Solar Cycles started somewhere around 1750. That seems a little strange. Our Sun is 4.6 billion years old. There are paintings on the rocks at Ubirr in the Northern Territory of Australia that are 40 thousand years old. The pyramids in Egypt are 45 hundred years old. The Solar Cycle has been going for a lot longer than the 7 million years there have been humans on the planet, let alone dinosaurs who experienced the Solar Cycle 66 million years ago. Using fossil records we've determined that the Solar Cycle has been stable for at least the last 700 million years. Chinese astronomers recorded Solar activity around 800 BC and Chinese and Korean astronomers frequently observed sunspots but no known drawings exist of these observations. The first person to draw sunspots was John of Worcester on the 8th of December 1128. Five days later, half a world away in Korea on the 13th of December 1128, the astronomers in Songdo reported a red vapour that "soared and filled the sky", describing the aurora borealis in the night sky that resulted from those very same sunspots. In the early 1600's there was plenty of activity around the recording of sunspots. Thomas Harriot appears to have predated Galileo Galilei by more than a year with notes and drawings dated the 8th of December 1610. There's plenty of other names during this period, Father and son David and Johannes Fabricius and Christoph Scheiner to name three, but I'm moving on. The Solar Cycle, was first described by Christian Horrebow who more than a century later in 1775 wrote: "it appears that after the course of a certain number of years, the appearance of the Sun repeats itself with respect to the number and size of the spots". Recognition of the Solar Cycle was awarded to Samuel Heinrich Schwabe who noticed the regular variation in the number of sunspots and published his findings in a short article entitled "Solar Observations during 1843" in which he suggested that the cycle was 10 years. Stay with me, we're getting close to Solar Cycle number One. In 1848 Rudolf Wolf devised a way to quantify sunspot activity. His method, named the Wolf number, is still in use today, though we call it the relative or international sunspot number. In 1852 he published his findings on all the available data on sunspot activity going back to 1610 and calculated the average Solar Cycle duration as 11.11 years. He didn't have enough observations to reliably identify Solar Cycles before 1755, so the 1755-1766 Solar Cycle is what we now consider Solar Cycle number One lasting 11.3 years with a maximum of 144.1 sunspots in June of 1761. Until 2009 it was thought that there had been 28 Solar Cycles between 1699 and 2008 with an average duration of 11.04 years, but it appears that the 15 year Solar Cycle between 1784 and 1799 was actually two cycles, making the average length only 10.7 years. I should also point out that there have been Solar Cycles as short as 8 years and as long as 14 years. With the announcement of Solar Cycle 25 comes improved propagation for anyone who cares to get on air and make noise. The current predictions vary depending on the method used, ranging from a very weak to a moderate Solar Cycle 25. There are predictions for the Solar maximum, the time with the most sunspot activity, to occur between 2023 and 2026 with a sunspot range between 95 and 130. By comparison during the previous Solar Cycle, in 2011 the first peak hit 99 and the second peak in 2014 hit 101. I have purposely stayed away from electromagnetic fields, geomagnetic impacts and the actual methods for HF propagation, I'll look at those another time. I can tell you that we've gone a little beyond counting dots on the Sun to determine activity and we have a whole slew of satel

Foundations of Amateur Radio If you have the opportunity to build your shack, it might start off as a table in the corner where you plonk down a radio, plug into nearby power and run coax to. That's pretty much how most shacks start, mine included. For me the step of running coax was an activity that took weeks of planning and procrastination and days of climbing on the roof. After actually completing that and getting two runs of coax to my planned shack, one for HF and one for UHF and VHF, the shack building itself was pretty simple. I had to get power to the location, but an extension lead took care of that. In the interest of space I put the power supply on the floor, a wooden floor that ensured good circulation, unlike carpet, perhaps a topic for another day, I plugged my coax into the radio, plugged in the 12 Volt power and was up and running. Over time that space continued to grow. Looking at it right now, it has two computer monitors, a laptop, three radios, two coax switches, a keyboard, mouse, digital interface, two speakers, and a fan to cool the radio when I'm calling CQ on FT8. I'm not a messy person, but I do like to have my tools convenient. It's not a pristine environment by any stretch, but it's orderly as shacks go. An hour ago it wasn't, actually, looking at the clock, that was four hours ago. Time flies when you're having fun. My shack is the centre of my radio activities. I might receive a gadget from a friend to test and I'll put it on my desk ready to go. The same is true for a foot pedal that I found when looking for something else, as is the audio adaptor that I used in the desk mixer that I'm experimenting with. Over time each of these bits and pieces accumulate on the surface. When I noticed that my radio was running hot, or in my mind uncomfortably warm, given that I'm using 5 Watts, I decided to invest in a fan, clipped to the edge of the desk requiring yet another wire. It's not limited to small bits. I'm testing a new radio, that comes with removable head, a microphone, cables to join those to the main body, two antenna port cables, a coax switch and a power lead with two cables. Over time you have coax mixed with 12 Volt DC and 240 Volt AC, audio leads, USB leads, video leads, grounding wire, remote control switches, microphone leads, CAT leads and more, all running all over the place. Making a minor change can become a big hassle, making it hard to determine what goes where, not to mention that each cable generates it's own little slice of RF, wanted or not. The four hours I've just spent consisted of taking everything except the bolted on computer monitors off the desk and starting from scratch. I also did this when I first added a second radio, but that was so long ago that the "system" I implemented then was unrecognisable. Doing it again today I made better use of the environment and changed some things around. I started with the 240 Volts requirements, then the coax, then 12 Volts, then audio and finally USB, using cable ties for semi-permanent things like power boards and hook and loop straps for things that move more frequently like audio wiring and video cables. It's not perfect. I'm looking for some flexible coax patch leads, there's USB cables going every which way, the laptop keyboard isn't used, so why use a laptop, no doubt I'll discover more. My point is that this is dynamic and every now and then it pays to spend a little while putting things back together. My next project is to use an audio mixer to bring all the audio together in one place so I can use one headset for everything and give me the opportunity to plug in a tape recorder as my regulator suggests for monitoring emergency communications, though I might have to come up with something a little less 1980 for the actual recording. If you're going to do this, move the desk at least a meter from the wall so you can get at the back of your shack, you can thank me later. I'm Onno VK6FLAB

Foundations of Amateur Radio A little while ago I was gifted a new radio, well, new to me. A Kenwood TS-480HX. It's an all mode HF transceiver with 6m. Does 200 Watts, but you know me, I'm into QRP, low power, so I first had to figure out how to dial the transmitter down to 5 Watts and that was after figuring out how to feed the dual power supplies from one source and have the fuses work as expected. When I received the radio, I took stock of all the bits that it was packed with, all complete, all the accessories, even the user manual was laminated. The previous owner, Walter VK6BCP (SK) whom I never met was an amateur after my own heart. I've talked about how he meticulously documented his alterations to a power supply for example. Previously I've taken this radio on holidays to operate portable in a field day. The experience was underwhelming, in that I didn't hear anyone and nobody responded to my CQ calls. At the time I put it down to a poor antenna and unfamiliarity with the radio, despite reading the manual, well, at least scanning it. Today I finally set some time aside to do some more testing. I decided that the first step would be to actually set it up in my shack, next to my trusty Yaesu FT-857d and see how it performs in comparison. So, I plugged everything in, found a coax switch so I could switch the antenna between the two radios and learned that the audio connector that I've been using for digital modes on the Yaesu is actually compatible with the Kenwood. Now I need to make another adaptor for this radio, but in the meantime I can move the audio plug between radios when I swap. In doing this I learnt a few things. One is that there's plenty of scope for things to break. For example, I was reaching over the desk to plug a connector into the coax switch when I leaned on the keyboard and touched the space bar. This caused the radio that I was working on to start its tuning cycle without an antenna connected. Fortunately I was using 5 Watts and I caught it within seconds, so no white smoke this time around. It does remind me to turn off the radio when fiddling with connectors though. I'm embarrassed to report that I thought I'd learnt that lesson already, nothing like a refresher course in transmitter safety and dumb things not to do in the shack. Then there was the thing about using remote control. In my naivety I thought that the connector that the Yaesu uses for computer control is also used on the Kenwood. Turns out that it isn't. Fortunately I read the manual before plugging that in. The Yaesu has a specific digital mode with individual gain and filter characteristics, which seem to be completely lacking on the Kenwood. I'm still attempting to learn the differences in receive performance between the two. I started this process by running WSJT-X and listening to WSPR or Weak Signal Propagation Reports and testing how both radios decode things. I cannot yet do this side-by-side, but for now I can swap and see signals coming in on either radio. This is not the first time I've put a different radio on my desk to see how it works and it's not going to be the last time. What I'm looking to achieve is to swap over from the Yaesu to the Kenwood in my shack, so I can put the Yaesu back in the car and have a mobile shack operating again because I have to admit, I do miss that. What kinds of testing regimes to you have when you're trying out a new radio? I'd love to hear your thoughts. My email address as always is [email protected]. I'm Onno VK6FLAB

Foundations of Amateur Radio Last weekend was memorable for all the right reasons. Filled with 24 hours of amateur radio, spent with friends, in a park, making noise and having fun, marking the first time I recall setting up in a park for that length of time with so few extra resources. Normally we'd be decked out with tents, or in my case a swag, we'd have camping stoves, perhaps even a caravan or two, tables, cutlery, the whole shebang. This time we brought none of that. Just radios, antennas, batteries, water with a few snacks and folding chairs. This was like nothing I've experienced before and it has me asking myself: Why did I wait so long to operate like this? It was wonderful. We spent it being on-air and making noise during a 24 hour contest which is specifically intended to celebrate and reward portable operation. In case you're wondering, the John Moyle Memorial Field Day is to encourage portable field day operation and provide training for emergency situations. It was created in memory of John Moyle, the long term editor of Wireless Weekly, who served in the RAAF with distinction. He's said to be responsible for a number of innovative solutions to keeping radio and radar equipment working under difficult wartime conditions. I've participated in this contest plenty of times before. This was the first time I did it in a park, in the city, and as experiences went it was fabulous and recommended. As you might know, I like operating portable. I've been operating from my car for years, from camp-sites in remote locations for just as long and I've activated several parks and peaks in Summits On The Air, or SOTA, and World Wide Flora and Fauna, or WWFF activities. I've also set-up during field days in local parks and I regularly drive to a local park to get on-air and make noise. With that as background, you might ask yourself, what is different? Let's start with setting the scene. The park that we used is located in a suburb about 10 km out from the city centre. It has a river running through it and on the banks there are plenty of trees with lawn. Dotted throughout are picnic tables with wooden gazebos. All very civilised. From a radio perspective, it was RF quiet, that is, no local electrical noise, away from cars, from a footpath, close enough to parking where we could get our gear out of the car and walk it to the site. All that alone would have made for a great experience, but this went beyond that. For example, dinner consisted of ordering from the local fish and chips shop five minutes away and picking up some amazing seafood. While there collecting some extra water and most importantly dessert from the supermarket next door. During our activities we had visits from local amateurs. Over the 24 hours we had a steady stream of interested hams coming out and having a chat. Some took the opportunity to bring food, dips and crackers, thermos flasks of tea, even ice cold beer. One amateur came along at the end of our activation and helped pack-up. All this made for a very enjoyable social experience. Another thing that was different was that the operator could wear headphones without stopping anyone else from hearing what was going on. We achieved that by connecting a headphone splitter to the radio, piping the audio to some external speakers for local monitoring whilst the operator wearing headphones would not be affected by conversations taking place around them. We did have some challenges. Our logging tool of choice was, for reasons we don't yet understand, switching bands which meant that sometimes the numbers we were giving out were not sequential. Generally in a contest situation you exchange a piece of information in addition to a signal report. In this case it's supposed to be a sequential number and because there were multiple operators, the sequence is supposed to be per band. The trees provided shade, but were not quite up to the task of being sky-hooks able to hold up wire antennas, fortunately we brought squid poles for that purpose. It was hot. 38 degrees Celsius. It turns out that even though wearing a black long-sleeve T-shirt is not a suitable fashion choice from a temperature perspective, it was perfect in preventing sunburn and for that I was immensely grateful. As you might know, we track what we bring in a spreadsheet, one row per item. A column for each time we go out. Over time we learn what's used and what's not. Our list is getting better and better. I'll admit that I felt some trepidation in relation to this location, but I'm so glad that I took a leap of faith and went with the experience. What a blast! What kind of activities have you been up to that gave you a blast? I'm Onno VK6FLAB

Foundations of Amateur Radio The landscape of remotely operated amateur radio is changing by the day. Once the territory of home brew DTMF decoders and remote controlled radio links, now more often than not it's a Raspberry Pi with an internet connection, or some variation on that. Before I continue, I must point out that amateur regulations vary widely around the globe, especially in this area. It appears mostly due to the rapidly changing nature of remotely operated radios. For example, most, if not all software defined radios are technically remotely operated. You run software on your computer, the radio is connected to a network, you twiddle a setting on your computer and the radio responds. The computer is not part of the radio, but without it there's not much radio to be had. There's no need for both to be in the same room, let alone the same building. Similarly, a Kenwood TS-480 and a Yaesu FT-857d are both radios that have a removable face with knobs and a display. The main body of the radio is a nondescript box with sockets for power and antenna, connected to the face essentially via a serial cable that can be a few centimetres long, or a few meters. There's solutions like RemoteRig that replace this serial cable with a virtual cable, allowing you to put the face in one location and the body in a different one, connected to each other across the internet. With the introduction of Starlink internet, a low earth orbit satellite based network, a connection to the internet can be made anywhere on earth, making it possible to have your station sitting somewhere far away from interference, powered by batteries and solar panels and connected to the internet. You might not even need to go to satellite based internet, the mobile phone network in many places is often more than sufficient for making such a station viable. If you're a member of a radio club, you might consider your club station. Often this station is the work of many volunteer years effort with multiple radios, antennas, filters and the like and often it sits idle most of the time, only getting fired up during club meetings or the weekend. What if you connected that station to the internet and offered it as a service to your members? Depending on license requirements, you might consider amateurs who have limited ability to build a shack but would love to be on air making noise. A remote club shack might be just the ticket for getting them on air. It could even become an income stream for your club. You might be able to offer access to trainees, or let them monitor the station without transmit ability whilst they're preparing for their license, or you might operate a 48 hour contest in shifts, all using the same transmitter, but from the comfort of your home. The landscape is full of different solutions, like RemoteRig, which I've already mentioned, RigPi Remote Station Server is a tiny computer that controls your radio and allows you access via a web browser or remote desktop connection. There's Remote Hams, a ready made solution for putting your shack on air with access control and remote management. You can connect specific radios, like the Elecraft K3 Remote System, or a Flex Radio Maestro, there's even web browser remote control projects like Universal Ham Radio Remote by Oliver F4HTB, each making it possible to get on air and make noise using a radio in a different location across the internet. All of the solutions I've named make it possible to fully use your radio, that means CW, SSB, FM, antenna control and the like. You can use it for FT8 or RTTY, the choice is yours. The interface might be the face of your radio, a special console, computer, phone or a tablet and you can operate it wherever and whenever the mood takes you. No longer do you need to have a shack in your home with coax snaking through the walls to an antenna whilst dodging the local authorities, or fighting the engine noise from your car. You can make the ultimate shack anywhere without taking up space in your home or car. One final comment. This is a moving feast. The level of functionality is increasing by the day. For me this journey started with a steel toolbox in my garage with a radio inside it and coax running from the box to my antenna. I have operated my radio and hosted my weekly net like this. The radio in the garage, me in my office connected via Wi-Fi over a virtual serial cable. You don't need to start this in the middle of nowhere, six hours drive over the back roads to fix a problem, you can start this project today at home. Where on this journey are you and what issues have you come up against? Let me know. My address as always is [email protected] I'm Onno VK6FLAB

Foundations of Amateur Radio Amateur radio is an environment for infinite possibilities. I've spoken about the way that contacts can happen, seemingly out of the blue, how propagation has so many variables it's hard to predict what will happen at any given moment. During a contest you might scan up and down the bands looking for an elusive multiplier, a contact that's worth extra points, or a missing DXCC country, in your quest to contact a hundred or more. It's easy to get swept away in the excitement and disappointment that comes with success and failure. I'm mentioning this because it's pretty much how many people in our community go about their hobby, me included. I've likened making a contact to fishing, taking your time to get the rhythm of the other station, understanding that there's a human at the other end. Taking stock of what they're hearing, which stations they're responding to, how they respond and if they give out hints about making a successful contact with them. The other day I came across a request to decode some Morse on an image showing long and short lines joined together in some form to serve an artistic purpose. Others pointed out that this wasn't Morse. I took an extra moment to point out that Morse had four individual attributes. It has a dit, a dah, a spacing between the letters and a spacing between the words, and since this image didn't have that it couldn't be Morse code. A few days later it occurred to me that I hadn't been paying attention. Morse actually has five attributes, it also has a spacing between each tone. I updated my answer and began to think about this interaction. It's not the first time that I've stopped to consider what's happening. For example, if I change bands on FT8, a digital mode that is very helpful for determining current propagation, I have a look at the level of activity. I'm generally not in a hurry, so I tend to leave it on the same band for a while, sometimes an hour, sometimes less, sometimes more. If the band is in full flight with every slot filled, it's easy to tick the "CQ Only" box and hide all the noise, or rather extra messages that form the exchange, but sometimes that noise has a whole lot of interesting information. You can determine if one of the stations calling CQ is actually answering anyone or if they're just an alligator, all mouth, no ears. You can see individual people attempting to get each other's attention, making a local or a long distance contact. You can type in an interesting grid locator that accompanies most CQ calls and see just how far it is from you and in which direction. I will also point out that using FT8 to observe a so-called dead band can be just as illustrative. It allows you to see signals in the waterfall, it decodes things that are barely visible and it will give you a feel for how your station at that location on that band at that time is performing in real-time. For example, it showed me that the squelch on my radio was turned on and blocking any chance of receiving weak signals, something that I wouldn't have noticed if I hadn't taken the time to observe. Another example. During a contest I often take some time to listen to a pile-up that surrounds a massive station to see what stations I can hear, who is coming in strong and who is coming in weak. I keep a mental or actual note of what cracks the S-meter with an indication of signal strength and what only turns up as audio, perfectly readable, but not exciting the needle in any way. I might not speak with any of those stations, but I know that there are stations in a particular location that I can hear. It's easy to get swept up in all this massive excitement that is our hobby, but sometimes it pays off to take a breath, to wait a moment, to take a look and have a listen to learn the lay of the land and understand what is happening and consider the implications. Within that moment of calm you might find an unexpected jewel in the rough. That's for example how I managed a contact with South Sudan several years ago during a massive pile-up in a club station during a contest. I'd love to hear what you have stumbled upon serendipitously like that. You can always get in touch, [email protected] is my address. I'm Onno VK6FLAB

Foundations of Amateur Radio Every community has its own language. As a member of that community you learn the words, their meaning and their appropriate use. For example, the combination of words "Single Side Band" have a specific meaning inside amateur radio. Outside of radio, those same words are random words with no relationship. Sometimes a term like "FM" can be heard across many communities with similar understanding, though not identical. It gets tricky when a word is used widely but doesn't have a common understanding at all. A word like "software" for example. A question you might hear in amateur radio is: "Can I buy a software defined radio or SDR that has digital modes built-in?" It's a perfectly reasonable question, the radio runs software, the digital modes are software, so the answer is obvious, right? What about: "Can the hundred or more computers in my car play Solitaire?" Aside from the perhaps unexpected fact that your car has computers on board, you most likely know the answer to that. No, since the computers are specialised for different tasks - and if you're driving a Tesla right now, yes, you can play Solitaire, but I'd recommend that you keep your eyes on the road instead. My point is that not all software is created equal. The software inside an SDR is essentially doing signal processing, often by several components, each running software, transforming an antenna signal into something, that can be used somewhere else, likely sound. The applications WSJT-X and fldigi, both software, use a computer running Linux, MacOS or Windows, software, to decode and encode digital modes while providing a way for you to interact with it. Software running on software. You might well argue that we should be running applications like that directly on our radio and on the face of it that sounds perfectly reasonable, except that to achieve that, you'd also need to build a system to install and update different types of applications, so you could run SSTV, APRS, RTTY, PSK31, FT8 or any of the other hundreds of digital modes and new ones as they are developed. If you did that, you'd also have to provide a way to manage the operating system, to connect to the Internet and provide security. You'd need to develop a user-interface, perhaps a keyboard and mouse solution, a screen, etc. Before long you'll have developed a whole computing infrastructure, much like the one we already have in the form of the computer on your desk or the phone in your pocket. Computers are getting faster and faster every day. This allows for the software on them to become more and more complex. The inter-dependencies are increasing by the second, but that doesn't mean that specialisation isn't useful. A software defined radio likely has a Field Programmable Gate Array, an FPGA on-board that is great at processing data in streams. It too runs software. Your microwave is running software, as is your television, your smart-watch, your battery charger, the gearbox in your car and your electric tooth brush. Making a distinction between the various types of software is helpful to understand what is possible and what is not. Being a computer nerd, I must point out that I've only barely scratched the surface of software here, in-case you're curious, microcode, firmware, hardware abstraction, the rabbit hole goes very deep. Not all software is created equal and every now and then it's a good idea to remember that when you talk about a word in one community, it might mean a completely different thing in another and sometimes the distinction is significant. As for having an SDR that runs WSPR, no. You can transmit from a computer though, but that's a whole other thing. I'm Onno VK6FLAB

Foundations of Amateur Radio Amateur radio lives and dies with the ionosphere. It's drilled into you when you get your license, it's talked about endlessly, the sun impacts on it, life is bad when the solar cycle is low and great when it's not. There's sun spots, solar K and A indices, flux, different ionosperic bands and tools online that help you predict what's possible and how likely it is depending on the time of day, the frequency, your location and the curent state of the sun. If that's not enough, the geomagnetic field splits a radio wave in the ionosphere into two separate components, ordinary and extraordinary waves. All that complexity aside, there's at least one thing we can all agree on. A radio wave can travel from your station, bounce off the ionosphere, come back to earth and do it again. This is known as a hop or a skip. If conditions are right, you can hop all the way around the globe. I wanted to know how big a hop might be. If you know that it's a certain distance, then you can figure out if you can talk to a particular station or not, because the hop might be on the earth, or it might be in the ionosphere. Simple enough right? My initial research unearthed the idea that a hop was 4000 km. So, if you were attempting to talk to a station at 2000 km or at 6000 km you couldn't do that with a hop of 4000 km. If you've been on HF, we both know that's not the case. If you need proof, which you really should be asking for, you should check out what the propagation looks like for any FT8 station, or any WSPR beacon over time and you'll notice that it's not 4000 km. Just like the crazy network of interacting parameters associated with propagation, the distance of a hop can vary, not a little, but a lot. In 1962, in the Journal of Geophysical Research D.B. Muldrew and R.G. Maliphant contributed an article titled: "Long-Distance One-Hop Ionospheric Radio-Wave Propagation". They found that in temperate regions such a hop might be 7500 km and in equatorial regions even 10,000 km. I'm mentioning this because this was based on observations and measurements. They used frequency sweeps from 2 to 49 MHz though they called them Mega Cycles, using 100 kHz per second, that is, over the duration of a second, the frequency changed by 100 kHz, so each sweep took nearly 8 minutes using only 15 kilowatts, so substantial gear, not to mention expense and availability. Oh, computers, yes, they used those too. A three tonne behemoth called an IBM 650, mind you, that's only the base unit, consisting of a card reader, power supply and a console holding a magnetic drum unit. You know I'm going somewhere with this right? Today, you can do the same measurements with a $5 computer and a $20 receiver. For a transmitter, any HF capable radio will do the trick, though you might not be transmitting long if you stray outside the amateur bands. For power, 5 Watts is plenty to get the job done. My point is that there is a debate around the future of our hobby and why modes like FT8 are such a controversial topic in some communities. I'm here to point out that since that publication in 1962 our hobby has made some progress and we can improve on the work done by people who came before us. We could build a glob-spanning real-time propagation visualisation tool, we already have the data and modes like FT8 keep feeding in more. If you're inclined, you could even make such a plot in real-time for your own station. So, how long is a hop? You'll just have to find out. I'm Onno VK6FLAB

Foundations of Amateur Radio One of the things about amateur radio that I find intensely fascinating and to be honest sometimes just as frustrating, is that you don't know what the outcome of an experiment might be at any one time. Not because you cannot control the experiment, or because you don't know what you're doing, but because the number of variables involved in most meaningful amateur radio experiments is pretty much infinite. I've spoken about this before, the idea that if you were to make a simple dipole antenna and fold the ends on each other, you'd have infinite variation in antennas with just a so-called simple antenna, since you can vary the shape of it in an unending variety of ways. The other day I was doing an experiment. An amateur radio one to be sure, but I was doing this within the realm of computing. I have been playing with digital modes for some time now and along the way shared some of what I've learnt. It occurred to me that I've been assuming that if you had the chance to follow along, you'd have access to the required hardware, simple enough, a $20 RTL-SDR dongle, but none-the-less, extra hardware. What might happen if you rule out that dongle and instead used a web-based receiver like WebSDR, or KiwiSDR, or any number of other such sites where you can pretty much tune to any band and frequency and see what's going on at a particular antenna location. For one it might allow you to decode something like APRS remotely, or decode an FT8 signal, perhaps even your own FT8 signal. Unfortunately most, if not all, of those sites include only the bare bones decoders for things like CW, AM, SSB and FM. After that you're pretty much on your own. You could do some funky stuff with a web-browser, linking it via some mechanism to the tool you use to actually decode the sound and there's some examples of that around, none that I really warmed to, since it requires that I open a web browser, do the mouse-clicky thing and then set-up some audio processing stuff. What if I wanted to figure out where the ISS was right now and wanted to listen to a receiver that was within the reception range of the ISS as it passed overhead, and automatically updated the receiver in real time as the ISS was orbiting the earth? For that to happen you'd need something like a command-line tool that could connect to something like a KiwiSDR, tune to the right frequency and extract the raw data that you could then decode with something appropriate. Turns out that I'm not the first person to think of this. There's even a project that outlines the idea of following a satellite, but it hasn't moved anywhere. There's also a project that is a command-line client for web-based KiwiSDR sites, but after spending some quality time with it and its 25 clones on github, I'm not yet at the point where this will work. Mainly because the original author made a design decision to record data to a file with a specific name and any clone I've found thus far only allows you to define what name to use. None so far actually appear to send their stream to something that can be processed in real time. Of course I could record a few minutes of data and process that, but then I'd have to deal with overlap, missing data, data that spans two files and a whole host of other issues, getting me further and further away of what I was trying to do, make a simple web-based audio stream digital mode decoder. As the Rolling Stones put it, "You Can't Always Get What You Want" And to me this sums up our hobby in a nutshell. When you call CQ, or go portable, or test an antenna, or attempt to build something new, there's going to be setbacks and unexpected hurdles. I think that it is important to remember that amateur radio isn't finished, it's not turn-key, no matter how much that appeals, you cannot find a one size fits all solution for anything, not now, not yesterday and not tomorrow. This hobby is always going to test boundaries, not only of physics, but your boundaries. It's after all one giant experiment. So, next time you don't get what you want, you might try something you find, and get what you need. Also, apologies to Keith Richards and Mick Jagger for butchering their words, a rockstar I am not. I'm Onno VK6FLAB

Foundations of Amateur Radio So, there's nothing on TV, the bands are dead, nobody is answering your CQ, you're bored and it's all too hard. You've run out of things to try, there's only so many different ways to use the radio and it's all too much. I mean, you've only got CW, AM, SSB, FM, there's Upper and Lower Side-band, then there's RTTY, the all too popular FT8, then there's WSPR, but then you run out of things. I mean, right? What about PSK31, SSTV, then there's AMTOR, Hellschreiber, Clover, Olivia, Thor, MFSK, Contestia, the long time favourites of Echolink and IRLP, not to forget Fusion, DMR, D-STAR, AllStar, BrandMeister or APRS. So far I've mentioned about 20 modes, picked at random, some from the list of modes that the software Fldigi supports. Some of these don't even show up on the Signal Wiki which has a list of about 70 amateur modes. With all the bands you have available, there's plenty of different things to play with. All. The. Time. There's contests for many of them, so once you've got it working, you can see how well you go. Over the past year I've been experimenting with a friend with various modes, some more successful than others. I'm mentioning this because it's not difficult to get started. Seriously, it's not. The most important part of this whole experiment is getting your computer to talk to your radio. If you have FT8 already working you have all the hardware in place. To make the software work, you can't go past installing Fldigi. As a tool it works a lot like what you're familiar with. You'll see a band-scope, a list of frequencies and a list of decodes. It's one of many programs that can decode and generate a multitude of amateur digital modes. If this is all completely new to you, don't be alarmed. There are essentially two types of connections between your computer and your radio. The first one is audio, the second is control. For this to work well, both these need to be two-way, so you can both decode the audio that the radio receives and generate audio that the radio can transmit. The same is true for the control connection. You need to be able to set the transmit frequency and the mode and you need to be able to read the current state of the radio, if only to toggle the transmitter on-and-off. If you already have CAT control working, that's one half done. I've spoken with plenty of amateurs who are reluctant to do any of this. If this is you, don't be afraid. It's like the first time you keyed up you radio. Remember the excitement? You can relive that experience, no matter how long you've been an amateur. Depending on the age of your radio, you might find that there is only one physical connection between your computer and the radio, either using USB or even Ethernet. You'll find that your computer will still need to deal with the two types of information separately. Notice that I've not talked about what kind of operating system you need to be running. I use and prefer Linux, but you can do this on any operating system, even using a mobile phone if that takes your fancy. Getting on air and making noise using your microphone is one option, but doing this using computer control will open you to scores of new adventures. I will add some words of caution here. In general, especially using digital modes, less is more. If you drive the audio too high you'll splatter all over the place and nobody will hear you, well, actually, everyone will, but nobody will be able to talk to you because they won't be able to decode it. If the ALC on your radio is active, you're too loud. WSJT-X, the tool for modes like FT8 and WSPR, has a really easy way of ensuring that your levels are right, so if you've not done anything yet, start there. Another issue is signal isolation. What I mean by that is you blowing up your computer because the RF travelled unexpectedly back up the serial or audio cable and caused all manner of grief. You can get all fancy with optical isolation and at some point you should, but until then, dial the power down to QRP levels, 5 Watts, and you'll be fine. A third issue that was likely covered during your licensing is the duty cycle. It's the amount of time that your radio is transmitting continuously as compared to receiving only. For some modes, like WSPR for example, you'll be transmitting for a full 2 minutes at 100%, so you'll be working your radio hard. Even harder might unexpectedly be using FT8, which transmits in 15 second bursts every 15 seconds, so there may not be enough time for your radio to cool down. Investing in a fan is a good plan, but being aware of the issue will go a long way to keeping the magic smoke inside your radio. I'm sure that you have plenty of questions after all that. You can ask your friends, or drop me an email, [email protected] and I'll be happy to point you in the right direction. Next time there's nothing good on TV, get on air and make some digital noise! I'm Onno VK6FLAB

Foundations of Amateur Radio Over the past little while I've been experimenting with various tools that decode radio signals. For some of those tools the signals come from space. Equipment in space is moving all the time, which means that the thing you want to hear isn't always in range. For example. The International Space Station or ISS has a typical orbit of 90 minutes. Several times a day there's a pass. That means that it's somewhere within receiving range of my station. It might be very close to the horizon and only visible for a few seconds, or it might be directly overhead and visible for 10 minutes. If it's transmitting APRS on a particular frequency, it can be decoded using something like multimon-ng. If it's transmitting Slow Scan TV, qsstv can do the decoding. I've done this and I must say, it's exciting to see a picture come in line-by-line, highly recommended. The National Oceanic and Atmospheric Administration or NOAA, has a fleet of satellites in a polar orbit that lasts about 102 minutes and they're overhead at least every 12 hours. You can use something like noaa-apt to decode the images coming from the various weather satellites, or a python script and I'll talk about that at some point. There is a growing cloud of cube satellites with interesting telemetry. They're in all kinds of orbits and you can attempt to receive data from each one as it's in sight. Keeping track of what's where and when is a full time job for plenty of people. As a radio amateur I'm happy to defer to the experts who tell me where a piece of equipment is and when I'm likely to be able to receive a radio signal from the transmitter I'm interested in. Previously I've mentioned in passing a tool called gpredict that does this heavy lifting for me. It presents a map of the world and shows what's visible at my location and when the next acquisition of signal for a particular satellite might occur. It talks to the internet to download the latest orbital information. It also has the ability to control a rotator to point your antenna, not that I have one, and it can update the transmit and receive frequency of your radio to compensate for the Doppler effect that changes the observed frequency as a satellite passes overhead. All this works with a graphical user-interface, that is to say, you have a screen that you're looking at and can click on. Whilst running gpredict, you can simultaneously launch the appropriate decoding tool for the signal that you're trying to receive. If you have a powerful enough computer, you can run multiple decoding tools together. You'll have separate windows for controlling the radio and antenna, for decoding APRS, SSTV, NOAA and if you're wanting to do sunrise and sunset propagation testing using WSPR, you can also run WSJT-X or any other decoder you're interested in. There are some implications associated with doing this, apart from needing a big enough screen, needing considerable computing power and burning electricity for no good reason, the signal that comes in from your radio will be fed to all the decoders at the same time and all of them will attempt to decode the signal, even when you know that this serves no purpose. That's fine if you don't know what you're listening to, but most of the time you know exactly what it is, even if the software doesn't. Manually launching and quitting decoders is one option, but what if the next ISS pass is at 3am? Aside from the computing requirements, so far this works fine with a standard analogue radio like my Yaesu FT-857d. The only limitation is that you can only receive one station at a time. If you replace the analogue radio with an RTL-SDR dongle, you gain the ability to record and decode simultaneous stations within about 2.4 MHz of each other. Another option is to use an ADALM Pluto and as long as the stations are within 20 MHz of each other, you can record and decode their signals. If you're not familiar with a Pluto, it's essentially a computer, receiver and transmitter, all in a little box, the size of a pack of cards. This is where it gets interesting. The Pluto doesn't have a screen, or a keyboard for that matter, but it's a computer. It runs Linux and you can run decoders on it. I've done this with ADS-B signals using a tool called dump1090. You'll find it on my GitHub page. One of the sticking points in decoding signals from space was the ability to predict when a satellite pass occurs without requiring a computer screen. Thanks to a command-line tool called "predict", written by John, KD2BD and others I've now discovered a way to achieve that. My efforts are not quite at the point of show-and-tell, but I've got a Docker container that's building and running predict on its own and using a little bash script it's telling me when the ISS is overhead. You'll find that on GitHub as well. My next challenge is to do some automated decoding of actual space signals. I'm going to start with the ISS, predict and multimon-ng. I'll let you know how

Foundations of Amateur Radio When you begin your journey as a radio amateur you're introduced to the concept of a mode. A mode is a catch-all phrase that describes a way of encoding information into radio signals. Even if you're not familiar with amateur radio, you've come across modes, although you might not have known at the time. When you tune to the AM band, you're picking a set of frequencies, but also a mode, the AM mode. When you tune to the FM band, you do a similar thing, set of frequencies, different mode, FM. The same is true when you turn on your satellite TV receiver, you're likely using a mode called DVB-S. For digital TV, the mode is likely DVB-T and for digital radio it's something like DAB or DAB+. Even when you use your mobile phone it too is using a mode, be it CDMA, GSM, LTE and plenty of others. Each of these modes is shared within the community so that equipment can exchange information. Initially many of these modes were built around voice communication, but increasingly, even the basic mobile phone modes, are built around data. Today, even if you're talking on your phone, the actual information being exchanged using radio is of a digital nature. Most of these modes are pretty static. That's not to say that they don't evolve, but the speed at which that happens is pretty sedate. In contrast, a mode like Wi-Fi has seen the explosion of different versions. During the first 20 years there were about 19 different versions of Wi-Fi. You'll recognise them as 802.11a, b, g, j, y, n, p, ad, ac and plenty more. I mention Wi-Fi to illustrate just how frustrating changing a mode is for the end-user. You buy a gadget, but it's not compatible with the particular Wi-Fi mode that the rest of your gear is using. It's pretty much the only end-user facing mode that changes so often as to make it hard to keep up. As bad as that might be, there is coordination happening with standards bodies involved making it possible to purchase the latest Wi-Fi equipment from a multitude of manufacturers. In amateur radio there are amateur specific modes, like RTTY, PSK31, even CW is a mode. And just like with Wi-Fi, they evolve. There's RTTY-45, RTTY-50 and RTTY-75 Wide and Narrow, when you might have thought that there was only one RTTY. The FLDIGI software supports 18 different Olivia modes out of the box which haven't changed for a decade or so. The speed of the evolution of Olivia is slow. The speed of the evolution of RTTY is slower still, CW is not moving at all. At the other end new amateur modes are being developed daily. The JT modes for example are by comparison evolving at breakneck speed, to the point where they aren't even available in the latest versions of the software, for example FSK441, introduced in 2001 vanished at some point, superseded by a different mode, MSK144. It's hard to say exactly when this happened, I searched through 15 different releases and couldn't come up with anything more definitive than the first mention of MSK144 in v1.7.0, apparently released in 2015. My point is that in amateur radio terms there are modes that are not changing at all and modes that are changing so fast that research is being published after the mode has been depreciated. Mike, WB2FKO published his research "Meteor scatter communication with very short pings" comparing the two modes FSK441 and MSK144 in September 2020, it makes for interesting reading. There are parallels between the introduction of computing and the process of archiving. The early 1980's saw a proliferation of hardware, software, books and processes that exploded into the community. With that came a phenomenon that lasted at least a decade, if not longer, where archives of these items don't exist because nobody thought to keep them. Floppy discs thrown out, books shredded, magazines discarded, knowledge lost. It didn't just happen in the 1980's. Much of the information that landed man on the moon is lost. We cannot today build a Saturn V rocket with all the support systems needed to land on the moon from scratch, even if we wanted to. We have lost manufacturing processes, the ability to decode magnetic tapes and lost the people who did the work through retirement and death, not to mention company collapses and mergers. Today we're in the middle of a golden age of radio modes. Each new mode with more features and performance. In reality this means that your radio that came with CW, AM, FM and SSB will continue to work, but if it came with a specialised mode like FSK441, you're likely to run out of friends to communicate with when the mode is depreciated in favour of something new. In my opinion, Open Source software and hardware is vitally important in this fast moving field and if we're not careful we will repeat history and lose the knowledge and skill won through perseverance and determination due to lack of documentation or depreciation by a supplier. When did you last document what you did? What will happen to that when you too become a s

Foundations of Amateur Radio This podcast began life under the name "What use is an F-call?" and was renamed to "Foundations of Amateur Radio" after 206 episodes. To mark what is effectively this, the 500th episode, I considered a retrospective, highlighting some of the things that have happened over the past decade of my life as a radio amateur. I considered marking it by giving individual credit to all those amateurs who have helped me along the way by contacting me, documenting things, asking questions, sharing their experiences or participating in events I attended. Whilst all these have merit, and I should take this opportunity to thank you personally for your contribution, great or small, to amateur radio, to my experience and that of the community. Thank you for making it possible for me to make 500 episodes, for welcoming me into the community, for being a fellow amateur. Thank you. During the week I received an email from Sunil VU3ZAN who shared with me something evocative with the encouragement to bring it the attention and appreciation it deserves. By way of introduction, on the 13th of June 2002, Ken, W6NKE became a silent key. Ken was an amateur, an active one by all accounts. I never met Ken, but his activity list is long and varied. Ken became interested in ham radio as a teenager in the 1930s. He was a long time advocate of CW and during WWII he taught Morse code to Navy operators. In 1975 he founded The Sherlock Holmes Wireless Society and was editor of its newsletter, now called "The Log of the Canonical Hams". He received his Investiture from The Baker Street Irregulars in 1981. Ken was an early member of the International Morse Preservation Society or FISTS, he held number 0818. He was the President of Chapter 2 of the Old Old Timers Club, the OOTC for many years. In addition to drawing cover art, Ken also wrote. Lots. 73 magazine features plenty of Ken's articles with titles like: "Inexpensive Vertical", "Don't Bug me Dad" and "The DX Hunter". Ken was also a poet, which brings us to the way that I think is appropriate to mark the 500th episode of this podcast. I'm confident that you can relate to this contribution by Ken to amateur radio, published in Volume 1, Number 3 of 73 magazine in December 1960. The Vagabond HAM, by Ken Johnson W6NKE (SK) A vagabond's life is the life I live Along with others, ready to give A friendly laugh and a word of cheer To each vagabond friend, both far and near. I travel the air waves, day or night To visit places I'll never sight From the rail of a ship, or from a plane Yet I'll visit them all again and again. I never hear from a far off land That my pulse doesn't quicken. With careful hand I tune my receiver and VFO dial To make a new friend and chat for awhile. Africa, Asia, they're all quite near In as easy reach as my radio gear With the flip of a switch, the turn of a knob I can work a ZL, a friend named Bob. There's an LU4, a fellow that's grand Who's described to me his native land 'Till I can hear the birds, and feel the breeze As it blows from the slopes of the mighty Andes. I learned of the surf, and a coral strand, The smell of hybiscus where palm trees stand 'Neath a tropical moon, silver and bright From an FO8 that I worked one night. I've thrilled to the tales of night birds' screams In the depths of the jungle where death-laden streams Flow'neath verdant growth of browns and greens From a DU6 in the Philippines. The moors of Scotland, a little French Shrine, German castles on the River Rhine Of these things I've learned, over the air Without ever leaving my ham shack chair. There's a KL7 on top of the world To whom the Northern Lights are a banner unfurled That sweeps across the Arctic night Makes the frozen sky a thing of delight. Tales of silver and gold and precious stones Ancient temples and molding bones Where the natives, I'm told, are tall and tan By an XE3 down in Yucatan. My vagabond trips over the air Will take me, well, just anywhere Where other vagabonds and I will meet From a tropical isle, to a city street. My vagabond's life will continue, I know Through the fabulous hobby of ham radio And one day from out at the world's end We'll meet on the air, my Vagabond friend. I'm Onno VK6FLAB Note: The spelling of the poem is as published in 73 magazine.

Foundations of Amateur Radio Amateur radio is a living anachronism. We have this heady mix of ancient and bleeding edge, never more evident than in a digital mode called Automatic Packet Reporting System or APRS. It's an amateur mode that's used all over the place to exchange messages like GPS coordinates, radio balloon and vehicle tracking data, battery voltages, weather station telemetry, text, bulletins and increasingly other information as part of the expanding universe of the Internet Of Things. There are mechanisms for message priority, point-to-point messages, announcements and when internet connected computers are involved, solutions for mapping, email and other integrations. The International Space Station has an APRS repeater on-board. You'll also find disaster management like fire fighting, earthquake and propagation reporting uses for APRS. There's tools like an SMS gateway that allows you to send SMS via APRS if you're out of mobile range. There's software around that allows you to post to Twitter from APRS. You can even generate APRS packets using your mobile phone. In my radio travels I'd come across the aprs.fi website many times. It's a place that shows you various devices on the APRS network. You can see vehicles as they move around, radio repeater information, weather, even historic charts of messages, so you can see temperatures over time, or battery voltage, or solar power generation, or whatever the specific APRS device is sending. As part of my exploration into all things new and exciting I thought I'd start a new adventure with attempting to listen to the APRS repeater on the International Space Station. I'm interested in decoding APRS packets. Seeing what's inside them and what kinds of messages I can hear in my shack. Specifically for the experiment at hand I wanted to hear what the ISS had to say. After testing some recommended tools and after considerable time hunting I stumbled on multimon-ng. I should mention that it started life as multimon by Tom HB9JNX, which he wrote in 1996. In 2012 Elias Oenal wanted to use multimon to decode from his new RTL-SDR dongle and in the end he patched and brought the code into this century and multimon-ng was born. It's available on Linux, MacOS and Windows and it's under active development. It's a single command-line tool that takes an audio input and produces a text output and it's a great way to see what's happening under the hood which is precisely what I want when I'm attempting to learn something new. In this case, my computer was already configured with a radio. I can record what the radio receives from the computer microphone and I can play audio to the radio via the computer speaker. My magical tool, multimon-ng has the ability to record audio and decode it using a whole raft of in-built decoders. For my test I wanted to use the APRS decoder, cunningly disguised as an AFSK1200 de-modulator. I'll get to that in a moment. The actual process is as simple as tuning your radio in FM mode to the local APRS frequency and telling multimon-ng to listen. Every minute or so you'll see an APRS packet or six turn up on your screen. The process for the ISS is only slightly different in that the APRS frequency is affected by Doppler shift, so I used gpredict to change the frequency as required; multimon-ng continued to happily decode the audio signal. I said that I'd get back to AFSK1200. The 1200 represents the speed, 1200 Baud. The AFSK represents Audio Frequency Shift Keying and it's a way to encode digital information by changing the frequency of an audio signal. One way to think of that is having two different tones, one representing a binary zero, the other representing a binary one. Play them over a loud-speaker and you have AFSK. Do that at 1200 Baud and you have AFSK1200. When you do listen to AFSK and you know what a dial-up modem sounds like, it will come as no surprise that they use the same technique to encode digital information. Might have to dig up an old dial-up modem and hook it up to my radio one of these days. Speaking of ancient. The hero of our story, APRS, dates back to the early days of microcomputers. The era of the first two computers in my life, the Apple II and the Commodore VIC-20. Bob WB4APR implemented the first ancestor of APRS on an Apple II in 1982. Then in 1984 he used a VIC-20 to report the position and status of horses in a 160km radius using APRS. As for the International Space Station, the APRS repeater is currently switched off in favour of the cross-band voice repeater, so I'll have to wait a little longer to decode something from space. I'm Onno VK6FLAB

Foundations of Amateur Radio When you join the community of radio amateurs you'll find a passionate group of people who to greater and lesser degree spend their time and energy playing with radios in whatever shape that takes. For some it involves building equipment, for others it means going on a hike and activating a park. Across all walks of life you'll find people who are licensed radio amateurs, each with their own take on what this hobby means. Within that community it's easy to imagine that you're the centre of the world of radio. You know stuff, you do stuff, you invent stuff. As a community we're a place where people dream up weird and wonderful ideas and set about making them happen. Radio amateurs have a long association with emergency services. When I joined the hobby over a decade ago one of the sales pitches made to me was that we're ready to be part of emergency communications. In some jurisdictions that's baked into the license. There was a time when a radio amateur was expected to be ready to jump into a communications gap and render assistance with their station. There are amateur based groups groups like WICEN, the Wireless Institute Civil Emergency Network in Australia, ARES, the Amateur Radio Emergency Service in the United States, RAYNET, the Radio Amateurs' Emergency Network in the United Kingdom, AREDN, the Amateur Radio Emergency Data Network in Germany, DARES, the Dutch Amateur Radio Emergency Service, AREC or Amateur Radio Emergency Communications in New Zealand and EmComms in Trinidad and Tobago to name a few. Each of those manages their participation in different ways. For example, ARES offers training and certification where AREDN offers software and a how-to guide, in Trinidad and Tobago the Office of Disaster Preparedness Management is actively involved in amateur radio and maintains an active amateur radio station and five repeaters. In Australia there's a requirement to record and notify authorities if you become aware of a distress signal as a part of your license. In fact in Australia 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. While that scenario can and has happened, it's not common. An amateur station being used to provide an emergency link in the case of catastrophic failure has also happened, but in Australia I'm not sure if that was in my lifetime or not. My point is that the idea that we're going to put up a critical radio link and be the heart of communications in an emergency is, in Australia at least, not particularly likely. That's not to say that you should ignore that potential, or that it's universally true, but it's to point out that there are other things that you can do with your license that might happen more readily and help your community more. Outside our amateur community, there's plenty of radio in use as well. The obvious ones are volunteer bush fire brigades, state emergency services and the like. Less obvious might be the local marine rescue group, surf life saving or the local council. Each of those use radios as part of their service delivery and a radio amateur can contribute to that without needing to bring their station along. In fact, if you don't have an amateur license, but want to play radio, that's an excellent place to do it as a volunteer. I should mention that radio procedures are also in use in all manner of other professions, mining, policing, the military and aviation to name a couple, not to forget occupations like tour-guides, ferry operators and pretty much any place where telephones, fixed or mobile are not readily deployed. Within those areas there are procedures and jargon that you'll need to learn and perhaps even need to be certified for, but you as a radio amateur have several skills that you can bring to the table because you already have a license. For example, I learnt my phonetic alphabet many years before I ever heard of amateur radio. It was a requirement for my aviation radio ticket which in turn was required before I flew solo. When it came to making my first ever transmission on amateur radio, doing the phonetic thing was second nature, much to the surprise of my fellow trainees at the time. A thank you is due to both Neil VK6BDO, now Silent Key, and Doug VK6DB for making that training happen. You can apply the skills you bring with you when you join an organisation outside amateur radio who deals with wireless communication in whatever form that takes. For example, just the idea that you know how to pick up a microphone and push the Push To Talk button and speak and let the button go after you're done, a pretty trivial activity in amateur radio, will be something that you have that most of the untrained general public have no idea about. Amateur radio is a massive hobby. Playing with radio, or doing something serious with it comes in all shapes and sizes. Your am

Foundations of Amateur Radio For decades I've been playing with every new piece of technology that comes my way. In amateur radio terms that's reflected in, among other things, playing with different antennas, radios, modes and software. One of the modes I've played with is slow scan television or SSTV. It's an amateur mode that transmits pictures rather than voice over amateur radio. A couple of months ago a local amateur, Adrian VK6XAM, set-up an SSTV repeater. The way it works is that you tune to the repeater frequency, listen for a while and when the frequency is clear, transmit an image. The repeater will receive your image and re-transmit it. It's an excellent way to test your gear and software, so I played with it and made it all work for me. In 2012 I was part of a public event where local schools participated in a competition to have the opportunity to ask an astronaut on board the International Space Station a question as part of the City of Light 50th anniversary of John Glenn's first orbit. The event was under the auspices of a group called Amateur Radio on the International Space Station or ARISS, an organisation that celebrated its 20th anniversary in 2020. Assisting with the logistics behind the scenes first hand and the amount of equipment used I'd gained a healthy respect for the complexity involved. The ISS has several radio amateurs on orbit. Among their on board activities are plenty of amateur radio friendly ones. In addition to ARISS, you'll also find repeaters, voice, packet and other interesting signals if you listen out for them. In previous years I've made abortive attempts at using my station to listen and transmit to space, with varying degrees of success. On a regular basis the ISS transmits SSTV using amateur radio. Often you'll find a series of images that commemorate an activity. During the final week of 2020 astronauts on the ISS celebrated 20 years of ARISS by transmitting a series of images on a rotating basis as the ISS orbits the earth. One of my friends made a throwaway comment about listening to the international space station and decoding slow scan television. I'd heard about this event on various social media outlets but put it in the too hard basket. Based on what I'd seen during my ARISS event, my own trials, and what local amateurs have been playing with in the way of interesting cross polarised antennas, rotators and the like, I'd decided that this was a long term project, unachievable with my current station. My station consists of a dual-band vertical antenna for 2m and 70cm on my roof at about 2m above ground level. The radio is my trusty Yaesu FT-857d. Connected to a Debian Linux laptop running three bits of software, rigctld, gpredict and qsstv. With a high level of apprehension I fired up my station, tuned my radio, updated the orbital information and radio frequencies and waited for the first acquisition of signal from the ISS. Imagine my surprise when a picture started appearing on my screen. It's a lot like the days of 300 baud dial up, getting a picture from some remote computer back in 1985. With that I managed to receive several of the images by just letting it run for the next couple of days. I'm glad my friend made their comment, because it spurred me into action to try for myself. I'll be the first to admit that the image quality isn't broadcast ready, or that I made mistakes, or that I should have started listening at the beginning of the week rather than the last few days, but all that is just noise because I can report that it works and I have the pictures to prove it! I now have most of the image series, number 2 is missing and I only have part of number 1, but there are some beauties among the 35 images I captured. I've published them on my project website at vk6flab.com, for you to have a look at and use as inspiration for your own seemingly impossible task. This leaves me wondering what else I can hear from overlying spacecraft using this set-up. What have you heard and what equipment were you using to make that happen? Are there any impossible tasks that you've avoided? I'm Onno VK6FLAB

Foundations of Amateur Radio The other day I wanted to know what kind of communication was possible between my station and the station of a friend of mine. We want to do some experiments and for that to be possible, we need to have a reliable communication channel. Traditionally you would get in touch with each other and attempt to find a suitable frequency on a band to make a QSO or contact. That generally involves picking a band, then tuning around the band, finding a frequency that's not in use, then listening, asking if the frequency is in use, then telling your friend via an alternative method where you are, only to have them tell you that they have noise at that particular frequency. You go back and forth a couple of times, finally settle in on a mutually convenient frequency and have a contact whilst keeping note of the signal strength shown on your receiver. On a good day that will take a few minutes, on a bad day that might take much longer or not work at all. If you want to do this across multiple bands, you have the fun of doing this whole thing multiple times. In case you're wondering, I've done this plenty of times and I will confess that it's an interesting combination of joy and frustration in attempting to get the answer to a pretty simple and common question: "Can I talk to my friend?" In my shack there are plenty of tools, digital multimeters, LC meter, antenna analyser and the like. No doubt you have some or more of those. Perhaps you have an oscilloscope, a vector network analyser, or other gadgets. None of those are particularly useful tools to solve this particular problem. On the other hand, you are likely to have a receiver and probably a transmitter. If you're reading or listening to this, you're likely to have a computer as well. Using a receiver and a computer as a tool to solve this problem might not have occurred to you. It hadn't occurred to me until recently that these are ideally suited for this particular repetitive task. So, I fired up my copy of WSJT-X and set it to WSPR mode. Changed the band to 2m and set it up to transmit. The other station did the same. Within a couple of minutes the results were coming in. We could both see what the link quality was like between us. Then we changed to 70 cm and did it again. Rinse and repeat for 10m. As it happens, the other station was receive only and they had to attend to some family activities and I was in my office earning a living, well actually, doing my bookkeeping, but you get the idea, you can do this test while you're doing something else. I checked in a couple of times to see how it was going when he pointed out that I could see his actual results on the WSPRnet.org website. I had been looking at the map with mixed results because it had been timing out for most of the day and when it did work, all I could see was that a message was decoded, not how well it was received. Randall VK6WR, the other station, then pointed me at the link to the database which I hadn't seen until then. If you're looking, it's at the top right. Out pops a list of all the WSPR spots his station reported, and as a bonus, the spots reported by another local amateur. If you know me at all it will come as no surprise that I used the opportunity to make a chart. Actually I made several, one showing the frequency drift between our stations, one showing the signal strength. Between the three bands it looks like 2m gives us the best opportunity for experimentation, though 70cm does appear to have some possibilities. Sadly 10m isn't with the antennas currently in the air, but I saw an email the other day with reports of a new vertical at the other end, so we'll have a go at doing the 10m test again in the very near future, perhaps even today. Right now from the WSPRnet.org website I'm downloading this month's WSPR reports from the Downloads section to see who else saw my signals. No doubt I'll make a chart or six. I'll keep you posted. I must thank Randall VK6WR for pointing me at the database link on the WSPRnet.org website, because that made propagation and link testing so much more useful and repeatable. Tools come in all shapes and sizes. What's one that unexpectedly helped you lately? I'm Onno VK6FLAB

Foundations of Amateur Radio Mark Twain is often misquoted in relation to reports about his death, pithy as always, he said: "The report of my death was an exaggeration." Similarly the death of amateur radio has been reported on many different occasions. Letting amateurs near a Morse key, banning spark-gap transmitters, introducing transistors, integrated circuits, computers, the internet, software defined radio, the list grows as technology evolves. I can imagine our descendants decrying the death of amateur radio with the commodification of quantum computing at some point in the future of humanity. Yesterday I had an entertaining and instructional play date with a fellow amateur. We discussed countless aspects of our hobby, things like how you'd go about direction finding if you had access to multiple radios and antennas, what characteristics that might have, what you'd need in the way of mathematics, how you'd write software to solve the problem and how you'd go about calibrating such a system. Could you use a local AM broadcast station as a calibration source, or do you need to generate a known signal? We started talking about how you'd send data across the network so you could have a dozen devices in different locations that you could synchronise and share data. How would you control it, how would you make use of existing standards, were there other tools like this already and what were their limitations. Then there was the conversation about using spectrum effectively, seeing current digital modes like FT8 and their level of effective use of a 2.5kHz slice of spectrum with 15 second time-slots and the theoretical bandwidth that you might achieve if you used that mode as a data transmission mode. There was the conversation around how you'd use propagation tools to determine path openings on the higher bands without needing a beacon, just a computer and a radio. Then we talked about how you'd go about making a simple WSPR beacon, based on a minimum component count and some readily available hardware, rather than a sophisticated transceiver like a PlutoSDR. There was a discussion around E-class amplifiers and their characteristics and potential pitfalls. We managed to cover a fair bit of ground in a few hours over our hot beverage of choice, a nice meal for lunch and despite me tripping over the threshold of my front door, banging my head against the wall and rolling my ankle. The head is fine, the ankle not so much. My point is that the world of amateur radio is never done, it's never finished, there's never an end. There's always more to discover, more to explore, build and investigate. How on earth could you contemplate that this was a hobby that had no relevance in the world today, let alone that of tomorrow. I for one am very happy to call myself an amateur and looking forward to discovering what else there is to play with. Why are you an amateur and does this feel like the end or a new beginning every day? The reports of the death of amateur radio was an exaggeration. I'm Onno VK6FLAB

Foundations of Amateur Radio One of the many vexing issues associated with getting on-air and making noise is actually making that happen. So, let's look at a completely restricted environment. An apartment building, seven stories off the ground, no ability to make holes, an unsympathetic council, restrictive local home owners association, et cetera, et cetera. On the face of it your amateur radio hobby is doomed from the start. In reality, it's only just beginning. So, to hear HF right now, today, you can go online and listen to a plethora of web-based software defined radios. There's the canonical WebSDR in Twente and a whole host of others using the same or similar software. There's KiwiSDR, AirSpy, Global Tuners, and many more. This will give you countless radios to play with, coverage across the globe, the ability to compare signals from different receivers at the same time on the same frequency, the ability to decode digital modes, find propagation, learn about how contests are done, the sky's the limit. I'll add that you don't need an amateur license for many of these resources, so if you're considering becoming part of the community of radio amateurs, this is a great way to dip your toe in the water. Think of it as a short-wave listening experience on steroids. I hear you say, but that's not amateur radio. To that I say, actually, it is. It's everything except a physical antenna at your shack or the ability to transmit. Permit me a digression to the higher bands. If you want to listen to local repeaters on UHF and VHF, listen to DMR and Brandmeister, you'll find plenty of online resources as well. You can often use a hand-held radio to connect to a local repeater which can get you onto the global Echolink, IRLP and AllStar networks. Failing that, there's phone apps to make that connection instead. Of course if you want to expand your repertoire to transmission, beyond a hand-held, you can. There are online transmitters as well. Many clubs have their club station available for amateurs to use remotely using a tool like Remote Hams. You'll get access to a radio that's able to transmit and you'll be able to make contacts, even do digital modes and contests. You will require an amateur license and access to such a station. Some clubs will require that you pay towards the running of such a service and often you'll need to be a member. Then there's actually going to the club, you know, physically, going to the club shack and twiddling physical knobs, though for plenty of clubs that's now also a computer since they're adopting software defined radios just like the rest of the community is. Using a radio via a computer can be achieved directly in the shack, but there's no reason to stay on-site. You can often use these radios from the comfort of your own shack. If you do want to get physical with your own gear, receiving is pretty simple. A radio with a wire attached to it will get you listening to the local environment. I have for example a Raspberry Pi connected to an RTL-SDR dongle that's connected to a wire antenna in my shack. It's listening across the bands 24/7 and reporting on what it hears. If you want to use an actual transceiver and you don't have the ability to set-up an antenna, kit out your car and go mobile. Failing that, make a go-kit with batteries, which as an aside will stand you in good stead during an emergency. Take your go-kit camping, or climbing, or hiking. Plenty of opportunities to get on-air and make noise. I hear you asking, what about having an antenna farm? Well, you can set one up in a farmers paddock and connect to it remotely - you will need permission from the land-owner - there's plenty of amateurs who use their country abode as a remote station. If you want to make noise at your actual shack, the antenna might be a piece of wire hanging from the balcony after dark, or an antenna clamped to the railing. You can use a magnetic loop inside your house. Some enterprising amateurs have tuned up the gutters in their building, or made a flagpole vertical, or laid a coax antenna on the roof. Have a look for stealth antennas, there's a hundred years of amateurs facing the same problem. My own station is very minimalist. There's literally a vertical antenna clamped to the steel patio. Using that I'm working the world with 5 Watts, 14,000 km on 10m, no kidding. Getting on-air and making noise doesn't have to start and finish with a Yagi on a tower. There's plenty of other opportunities to be an active amateur. I'm Onno VK6FLAB

Foundations of Amateur Radio Over the past nine and a half years I've been hosting a weekly radio net for new and returning amateurs. Called F-troop, it runs every Saturday morning at 0:00 UTC for an hour. Feel free to join in. The website is at http://ftroop.vk6flab.com. In making the better part of six thousand contacts during that time I've learnt a few things about how nets work and how there are built-in assumptions about how a contact is made. There are several things that seem universally accepted that are not actually supported by the evidence and repeating them to new amateurs is unhelpful. For example, there is an assumption that on 2m there is signal reciprocity. By that I mean, what you hear is what the other party hears. On HF, contrary to popular belief, this is also not universally true due to massive power and antenna differences and signal reports on FT8 bear that out - for example, my signal is often reported at least 9 dB weaker than the other station. The reason that on 2m this isn't the case is because in general there is at least one other transmitter involved, the repeater. If you're joining in via a remote network, either via RF or via the Internet, there are even more times when this isn't true, but let's stay with the simple scenario of a single repeater and two stations. If I'm using a base-station with a fixed antenna, my connection to the repeater is rock-solid. If you are using a hand-held and you're on the move, your connection to the repeater is anyone's guess. It could be great, it could be poor or even non-existent. Not only that, the repeater is often using higher power, sometimes much higher. On average the repeaters near me are using 30 Watts, the highest uses four times that, the lowest uses 10 Watts. In contrast, a handheld uses at most 5 Watts, but more likely than not, half that. Receiving a strong signal on a hand-held is simple, transmitting a weak signal to a repeater is not. The point is, you might be hearing me as-if I'm sitting next to you, but I might be hearing you on the other end of a really scratchy and poor, intermittent and interrupted link. If you add other repeaters and links with differing volume or gain settings to the mix, you get the idea that a 2m conversation may in many ways act like a HF contact. That implies that there are plenty of times when you should use phonetics to spell your callsign and anything else of interest, despite the often repeated assertion that you don't use phonetics on 2m. Another assumption is that 2m is less formal than HF. The people you talk to on 2m are likely to be local, perhaps people you've met at a HAMfest, face-to-face. You recognise their voice, you know their situation, their station and their habits. On HF however, you have contact with people across the globe, most of whom you've never met, will never meet, have no idea about, let alone have a relationship with. That's not to say that you cannot have a friend on HF, I have plenty of people whom I speak with on HF, often during a contest, whom I've never met, but whom I speak with regularly on air. I can similarly recognise their voice, their callsign and know what to expect. The point is that the more you look at the differences between 2m and HF, the more you realise that they are the same. Interestingly, as an aside, a contact on 10m or 15m can on plenty of occasions sound like a strong local FM contact. My advice is to not think of 2m as a "special" band, but to think of it as an amateur band with a set of conditions. By law you are required to announce your callsign every ten minutes and at the beginning and the end of each contact. Note that this doesn't mean at the beginning and end of each over. In case that doesn't make sense to you, a contact is the whole conversation from start to end. Each time a station transmits during that contact is an over. You should vary how you identify yourself, using phonetics or not, at the minimum required interval, or on every over, depending on the circumstances, not depending on the band. Look forward to making contact with you on what ever band. You can get in touch via email, [email protected] is my address and if you're into Morse, this podcast is also available as a Morse-code audio file. I'm Onno VK6FLAB

Foundations of Amateur Radio The other day I was adding an item to my to-do list. The purpose of this list is to keep track of the things in my life that I'm interested in investigating or need to do or get to finish a project. My to-do list is like those of most of my fellow travellers, unending, unrelenting and never completed. As I tick off a completed item, three more get added and the list grows. Given some spare time and to be honest, who has that, I am just as likely to find an item on my to-do list that was put there yesterday as an item that was put there 10 years ago. Seriously, as I migrate from platform to platform, my to-do list comes with me and it still has items on it that haven't been done in a decade, let alone describe what project it was for. Of course I could just delete items older than x, but deciding what x should be is a challenge that I'm not yet willing to attack. Anyway, I was adding an item to the list when I remembered seeing something interesting on the shed wall of a fellow amateur. There were two pieces of printed paper with a list of to-do items on it. Looking pretty much like my to-do list, except for one salient detail. Each to-do list was for a different project. At the time I spotted it I smiled quietly to myself and thought, yep, keeping track is getting harder for everyone. Bubbling away in the back of my mind this notion of a to-do list for a single project kept nagging at me. Yesterday it occurred to me why it was nagging. If you have a to-do list for every project then once the project is done, the to-do list is done. Not only that, the items on a project to-do list don't really grow in the same way as an unconstrained to-do list does. It also has a few other benefits. The sense of satisfaction towards completing a project is amplified as each item is ticked off and ultimately the project is done. I'm sure that project managers already know this, might even have a name and a process for it. No doubt there are aspects that I've not considered, like for example, the never ending range of projects or the trap of a miscellaneous catch-all project, but I'll cross those bridges when I run into them. As of right now, this gives me an improvement on my stifling life to-do list and it brings great satisfaction when I can tick off a whole project. No doubt you've gotten to this point wondering what this has to do with amateur radio? If it hasn't occurred to you, consider what's involved into setting up a portable power supply for when you activate on a field-day, what you need do to get logging working, what needs to happen to get ready for a contest, what you need to do when you're selecting your next radio, how you're going to prepare for the park activation next week and so-on. If you have insights into this, feel free to get in touch. [email protected] is my address. Speaking of me, did you know that "Foundations of Amateur Radio" is a weekly podcast and that we're up to episode 285? If you haven't already and you're itching to get your hands on even more content, before episode 1 there was another podcast, "What use is an F-call?" It has 206 episodes and other than the name and my youthful self, the content is more amateur radio. If I've done everything right there won't be much in the way of overlap in those 491 episodes, other than the same unrelenting quest for new and exciting things to do with Amateur Radio, but then you already knew that. Now where's my podcast to-do list? * Tell you about "What use is an F-call?", tick. * Tell you that I'm nearly at 500 episodes, tick. * Finish recording this episode, tick. I'm Onno VK6FLAB

Foundations of Amateur Radio When one WSPR receiver just isn't enough The other day during a radio play date, highly recommended activity, getting together with friends, playing radio, seeing what you can learn, we were set-up in a park to do some testing. The idea was an extension on something that I've spoken about previously, using WSPR, Weak Signal Propagation Reporter, to test the capabilities of your station. If you're not familiar with WSPR, it's a tool that uses your radio to receive digital signals from WSPR beacons across the radio spectrum. Your station receives a signal, decodes it and then reports what it heard to a central database. The same software can also be used to turn your station into a beacon, but in our case all we wanted was to receive. If you leave the software running for a while you can hear stations across many bands all over the globe. You'll be able to learn what signal levels you can hear, in which direction and determine if there are any directions or bands that you can receive better than any other. We set up this tool in a park using a laptop, a wire antenna and a radio running off a battery. In and of itself this is not particularly remarkable, it's something that has been done on a regular basis all over the globe, and it's something that I've been doing on-and-off for a few years. What made this adventure different is that we were set-up portable about a kilometre up the road from the shack, whilst leaving the main WSPR receiver running with a permanent antenna. This gave us two parallel streams of data from two receivers under our control, using different antennas in slightly different conditions, within the same grid-square, for the purpose of directly comparing the data between the two. Over a couple of hours of data gathering we decoded 186 digital signals, pretty much evenly split between the two receivers. More importantly, the stations we heard were the same stations at the same time which gave us the ability to compare the two decoded signals to each other. One of the aspects of using WSPR is that it decodes the information sent by a beacon. That information contains the transmitter power, the grid locator and the callsign. After the signal is decoded, the software calculates what the signal to noise ratio was of the information and records that, additionally giving you a distance and direction for each beacon for that particular transmission. I created a chart that showed what the difference was between the two, plotted against the direction in which we heard the decode. This means that you can compare which antenna can hear what in which direction in direct comparison against the other. In telling this story another friend pointed out that the same technique could be used to compare a horizontal vs. a vertical antenna, even compare multiple bands at the same time. It looks like I might have to go and get myself a few more RTL-SDR dongles to do some more testing. If you don't have a spare device, there's also the option of comparing other WSPR stations that share a local grid square, so you can see what other people near you can hear and if you like, use it as an opportunity to investigate what antenna system they're using. WSPR is a very interesting tool and putting it to use for more than just listening to a band is something that I'd recommend you consider. I've already created a stand-alone raspberry pi project which you can download from GitHub if you're itching to get started. Thank you to Randall VK6WR for continuing to play and to Colin VK6FITN for expanding on an already excellent idea. If you would like to get in touch, please do, [email protected] is my address. I'm Onno VK6FLAB

Foundations of Amateur Radio Radio amateurs like to do new things, celebrate, remember, bring attention to, and overall have fun, any excuse to get on air. One of the things that we as a community do is setup our radios in weird and wonderful places, on boats, near light-houses, on top of mountains, in parks, you name it. Another thing we do is create special callsigns to mark an occasion, any occasion. For example, to mark the first time the then Western Australian Chief Scientist, Professor Lyn Beazley was on air she used the callsign VI6PROF. When Wally VK6YS (SK) went on the air to educate the public about Rotary's End Polio Now campaign, he used VI6POLIO. More recently the Australian Rotarians of Amateur Radio operated VK65PFA, Polio Free Africa. When it's active, you'll find VA3FIRE to remind you of Fire Prevention Week in Canada, the Chinese Radio Amateurs Club operates B0CRA through to B9CRA which you can contact during the first week of May each year as part of the Chinese 5.5 Ham Festival. We create callsigns for other things too. Datta VU2DSI commemorates November 30th, the birthday of Indian physicist Sir Jagadish Chandra Bose named by the IEEE as one of the fathers of radio science, by operating a special callsign AU2JCB in his honour for a couple of weeks around the end of November. I mention this because it's not hard to achieve. It's called a "Special Event Callsign" and many if not all amateur licensing authorities have provision for such a callsign. Rules differ from country to country, some say that the callsign must be for something of special significance to the amateur community, others require that it's of national or international significance. In Canada for example, if you're celebrating an anniversary, it must be a minimum of a 25th increment. Different countries have different formats. The USA for example issues temporary one by one calls consisting of a letter followed by a digit followed by a letter. The UK offers GB and a digit followed by two or three letters. There's also "Special" Special Event Stations, which can have a format like GB100RSGB. In Canada there's a whole system based on what kind of event, what region it's significant to, who's operating it, and so on. In the Netherlands you can have a normal prefix followed by at most eight characters and an overall maximum length of twelve characters and you can have it for at most a year and only one at a time. In Germany you can use a standard callsign pattern with a four to seven character suffix, but only for a limited time. In Australia there's the traditional VI and a digit followed by any number of characters, but remember if you make it massive, getting it in the log is not always easy and using a digital mode like FT8 might not work as expected. What ever you want to commemorate, celebrate or bring attention to, remember that your callsign is only one part of the process. Consider who's going to actually operate the callsign, if you're going to issue QSL cards, if there are awards or a contest associated with the callsign, if there needs to be a website, if this is a regular thing, or a once-off. Another thing you need to consider is how you're going to publicise this callsign. There's no point in going to the effort of obtaining a special event callsign with nobody knowing about it, that's the whole point. No matter which way you jump, there's always a large range of special event callsigns on the air at any one time and making contact with one is often a massive thrill for the person operating the callsign, not to mention the person making the contact. So, if you have a chance to have a go, I'd encourage you to get on air with a special event callsign and make some noise! I'm Onno VK6FLAB

Foundations of Amateur Radio The idea of building a crystal radio occurred to me a little while ago. I committed to building one, supplies permitting, before the end of the year. I can report that I now have a crystal radio. It works, as-in, I can hear a local AM broadcast station, and it took a grand total of three components costing a whopping two and a half bucks. Before I get into it, this isn't glorious AM stereo, or even glorious AM mono, this is scratchy, discernible, unfiltered, temperamental radio, but I built it myself, from scratch and it worked first time. Before I start describing what I did and how, I'm letting you know in advance that I'm not going to tell you which specific components to buy, since your electronics store is not likely to have the same components which would make it hard for you to figure out what would be a solid alternative if you didn't understand the how and why of it all. So, disclaimer out of the way, my aim was to build a crystal radio using off the shelf components without needing to steal a razor blade, shave a cat, sharpen a pencil or any number of other weird contraptions. Not that those aren't potentially interesting as life pursuits, though the cats I know might object strongly, I wanted this to be about learning how this thing actually works without distraction. I set about finding a capacitor and an inductor combination that made a resonant circuit with a frequency range that falls within the AM broadcast band. If you recall, you can make a high-pass filter from either a capacitor or an inductor. Similarly, you can make a low-pass filter from either component. If you line up their characteristics just so, you'll end up with a band-pass filter that lets the AM broadcast band pass through. Now notice that I said range. That means that there needs to be something that you can adjust. In our case you can either adjust the inductor, or the capacitor, technically you could do both. My electronics store doesn't have variable inductors, so I opted for a variable capacitor. The challenge becomes, which variable capacitor do you select with which inductor? I used a spreadsheet to show what the bottom and the top range for each capacitor would be if combined with each inductor. This gave me a table showing a couple of combinations that gave me a range of resonance inside the AM band. The formula you're looking for is the resonant frequency for a parallel LC circuit. Take the inductance and multiply that by the capacitance, then take the square root, multiply it by pi and again by two, then take the inverse and you'll have the resonant frequency. You'll need to pay attention to microhenry vs millihenry, and picofarad vs nanofarad and you'll also need to confirm that you've got kHz, MHz or just Hz out the other end, otherwise you'll end up several orders of magnitude in the wrong spot. If you do all that, you'll likely end up with a couple combinations of inductor and capacitor that will do what you want. Then when you head to the electronics store, you'll find that the stock you're looking for is end-of-life and that the colour coding on them isn't right, but if you manage to navigate that swamp, you'll come out the other end with a few parts in your hands. Final bit you'll need is a diode. It acts as a so-called envelope detector. I'm not getting into it here, I'll leave that for another time, but a Schottky or Germanium diode is likely going to give you the best results for this experiment. Wiring this contraption is pretty trivial. Start with joining the inductor and capacitor to each other in parallel, they'll act as the LC circuit. You can change the resonance by tweaking the variable capacitor. Then attach a long antenna wire to one end and an earth wire to the other end. Finally, connect the diode and an amplified loudspeaker in series between the LC antenna end and the LC earth end and your radio is done. For my experiment the loudspeaker has a built-in amplifier, it's an external PC speaker with a power supply. I also had to keep my hand on the antenna to create enough signal - since essentially I'm a large body of water - great for being a surrogate antenna. The unexpected thrill of hearing a local announcer coming through into my shack from three components lying on my desk was worth the anticipation. Highly recommended. What are you waiting for? I'm Onno VK6FLAB

Foundations of Amateur Radio I'm looking at components. Not looking for, looking at. I have them sitting on the bench in front of me. A collection of six variable capacitors and six inductors. There's also a germanium diode, a breadboard, some connecting wires and two connectors. I don't quite need that many capacitors or inductors and truth be told a breadboard is overkill, but I found myself getting into the spirit of things and for the tiny investment it seems like the thing to get whilst you're dipping your toe into the art of electronic circuit prototyping. I am noticing something odd whilst I'm looking at these components, a familiar feeling in some ways, butterflies in my stomach. It's the exact same feeling as when I sit at the radio, getting ready to speak into the microphone just as I am starting a weekly radio net, something that I've now done about 480 times, not to mention the times when I did around 1600 interviews or broadcast live to the world, butterflies. I'm mentioning this because in many ways this is a momentous event, not for the world, not for humanity, not even for the hobby, but for me. It's the first time I'm building a circuit completely from scratch, no pre-made circuit board, no pre-selected components, no building instructions, just me, some resonance formulas and the hope that I've understood what they represent and that the components I selected will do what my calculations say they should. To make this even less exciting, there's no external power, nothing that's going to go boom or let magic smoke escape, nothing that will break if I get it wrong, but still. The other day I received an email from Phil, WF3W. We have been exchanging email for a couple of years now. He's a member of the Mt Airy VHF Radio Club in Pennsylvania in the United States. His email outlined an interesting question. What do new amateurs get excited about in this era of the ubiquitous world wide web? As a hobby we're attracting new members every day. Many of those are coming to the community by way of social media, rather than using things that are more traditionally considered radio like HF DX, making long distance contact using HF radio, rather than exchanging pithy emails or instant messages via the interconnectedness of the globe encompassing behemoth of the Internet. The answer came easily to me, since last week we had a new amateur, Dave VK6DM who made his very first long distance HF contact between Australia and the United States. His level of excitement was contagious and that's something that I've found happens regularly. Someone talks about magnetic loop antennas and the next thing six amateurs are building them. One person starts playing with satellites and before you know it YAGIs are being built and people are describing their adventures. The same is true with my crystal radio. I've talked about it a couple of times and people are digging out their old kits and telling stories about how they grew up with their dad making a crystal radio. That's what is exciting the new amateurs. The internet is just an excuse to find each other, just like F-troop is an excuse for people to turn on their communications tool of choice at midnight UTC on a Saturday morning to talk about amateur radio for an hour. My excitement comes from trying new things and just like keying a microphone for the first time, there's this almost visceral experience of anticipation associated with starting. I'm still working out how I want to build my new toy and how to go about testing to see if it actually works and what to look for if it doesn't. I'm trying hard to resist tooling up with crazy tools like signal generators and oscilloscopes, instead opting to use things I already have, like LC meters and my ears. I can't wait until I can share how it goes. I'm Onno VK6FLAB

Foundations of Amateur Radio Antenna testing in the field. If you've been around amateur radio for any time at all, you'll know that we spend an awful lot of time talking about antennas. How they work, where to get them, how to build them, how strong they are, how cheap they are, how effective, how resonant, you name it, we have a discussion about it. It might not be immediately obvious why this is the case. An antenna is an antenna, right? Well ... no. Just like the infinite variety of cars on the road, the unending choice of mobile phones, ways to cook an egg and clothes to wear to avoid getting wet, antennas are designed and built for a specific purpose. I've talked at length about these variations, but in summary we can alter the dimensions to alter characteristics like frequency responsiveness, gain, weight, cost and a myriad of other parameters. If we take a step back and look at two antennas, let's say a vertical and a horizontal dipole, we immediately see that the antennas are physically different, even if they're intended for exactly the same frequency range. Leaving cost and construction aside, how do you compare these two antennas in a meaningful way? In the past I've suggested that you use a coax switch, a device that allows you to switch between two connectors and feed one or the other into your radio. If you do this, you can select first one antenna, then the other and listen to their differences. If the difference is large enough, you'll be able to hear and some of the time it's absolutely obvious how they differ. You might find that a station on the other side of the planet is much stronger on one antenna than on the other, or that the noise level on one is much higher than the other. Based on the one measurement you might come to the conclusion that one antenna is "better" than the other. If you did come to this conclusion, I can almost guarantee that you're wrong. Why can I say this? Because one of the aspects of the better antenna is dependent on something that you cannot control, the ionosphere, and it is changing all the time. I have previously suggested that you listen to your antenna over the length of a day and notice how things change, but that is both time consuming and not very repeatable, nor does it give you anything but a fuzzy warm feeling, rather than an at least passing scientific comparison. A much more effective way is to set up your station, configure it to monitor WSPR, or Weak Signal Propagation Reporter transmissions using one antenna, for say a week, then doing it again with the other antenna. If you do this for long enough you can gather actual meaningful data to determine how your antenna performs during different conditions. You can use that knowledge to make more reliable choices when you're attempting to make contact with a rare station, or when it's 2 o'clock in the morning and you're trying to get another multiplier for the current contest. You don't even have to do anything different and spend little or no money on the testing and data gathering. You can do this with your normal radio and your computer running WSJT-X, or with a single board computer like a raspberry pi and an external DVB-T tuner, a so-called RTL-SDR dongle, or with an all-in-one ready-made piece of hardware that integrates all of this into a single circuit board. If you want to get really fancy, you can even use automatic antenna switching to change antennas multiple times an hour and see in real-time what is going on. You also don't have to wait until you have two antennas to compare. You can do this on a field day when you get together with friends who bring their own contraptions to the party. If there's any doubt in your mind, you can start with a piece of wire sticking out the back of a dongle. I know, I'm looking at one right now. I've been receiving stations across the planet. One thing I can guarantee is that the more you do this, the better you'll get a feel for how the bands change over time and how to go about selecting the right antenna for the job at the time. I'm Onno VK6FLAB

Foundations of Amateur Radio Recently I made a commitment to building a crystal radio. That started a fevered discussion with several people who provided many helpful suggestions. This is the first time I'm building a crystal radio and to make things interesting I'm selecting my own components, and circuit diagram. What could possibly go wrong? Crystal radios have been around for a while. Around 1894 Indian physicist Jagadish Chandra Bose was the first to use a crystal as a radio wave detector, using galena detectors to receive microwaves. He patented this in 1901. The advice I was given sometimes feels like it harks back to 1894, with suggestions of using cats whiskers, razor blades, and any number of other techniques that create the various components to make a so-called simple crystal radio. At the other end of the scale there were suggestions to go to the local electronics store and buy a kit. The first suggestions, rebuilding historic radios from parts made of unobtanium would mean many hours of yak shaving, just to get to the point of getting the components, rather than actually building the radio. I realise that part of the experience is the journey and I'm sure that if my current project gets me hooked I'll look into it, but I really don't want to become that amateur who has a collection of home-brew crystal radios across the ages. Besides, I'm having a look at using my crystal radio as a front end to my software, so I want to keep sight of the radio part of what I'm doing, rather than the building part. Before you get all hot and bothered, remember, amateur radio is a hobby that means different things to different people and for me I'm currently playing with software and I'm attempting to learn about the electronics principles that form the basis of our hobby. As I said, the other end of the scale was to get a kit and build that. It has its appeal, but there's little in the way of learning and the construction part of things is pretty much putting together a kit which is something I first did when I constructed an LC meter kit a while ago. So that too doesn't really appeal to me. Now comes the bit where I tell you what I've done to date. On the physical side of things, nothing. On the thinking and learning and planning side, lots. Here's where I'm at. My current understanding of a crystal radio is that you need to detect the AM wave form of an RF frequency and pipe that into something that makes noise. Traditionally this is done with a crystal earpiece, but I saw someone use powered computer speakers with a built in amplifier, so I'm going to start with that as my first noise maker. I should also mention that the crystal earpiece was a source of confusion. I thought that the crystal in crystal radio was referring to that one. It's not. So, back to where I'm at. What do I need? To start off, I cannot just connect an antenna to a speaker, since it will attempt to make sound for every known frequency, well, at least the ones that the antenna can handle that fit within the response envelope of the speaker and its amplifier. If you want to know what that sounds like, put your finger on the input plug to some powered speakers. Don't turn up the volume too loud, you'll regret it. So step one is to make a way to only let specific frequencies through. I've previously discussed this. You might know it as a band-pass filter. You can make one using a capacitor and an inductor. If you make the capacitor variable, you can change what frequency passes. This is helpful because you don't want to be decoding more than one radio station at a time. There are plenty of designs for crystal radios that offer hand wound inductors and home brew capacitors, but I'm not doing this to learn how to build those, I'm doing this because I want to learn how it works. I want to use readily available components from my local electronics store, so I started with building a spreadsheet that shows what the resonant frequency is for a combination of inductors and variable capacitors. Today I learnt that I also need to pay attention to how wide this is, so I'll be revisiting this. There are only two more components in my radio, a diode and another capacitor. The diode cuts off half of the information, since if you recall, AM uses two side-bands that are identical. At that point you have a signal that contains both the carrier and the audio signal. You need one last step, filter out the high frequency carrier. I've talked about that too, this is a low-pass filter. You can do this with a capacitor. So, now we have the bare-bones of a crystal radio, made from four components, an inductor, a variable capacitor, a diode and another capacitor. My next challenge is to figure out what values they have so it will allow me to listen to my local AM radio station and do it using components off the shelf from my electronics store. One thing I can tell you is that this is precisely why I signed up for this project. I don't want a ready-made radio from

Foundations of Amateur Radio One of the more fundamental aspects of long distance radio communication is the impact of the ionosphere. Depending on how excited the Sun is, what time of day it is and what frequency you're using at the time will determine if the signal you're trying to hear from the other side of the planet makes it to you or is on its way to a radio amateur on Proxima B who is likely to hear this podcast in just over 4 years from now. In other words, the ionosphere can act like a mirror to radio waves, or it can be all but invisible. As luck would have it, this changes all the time. Much like waiting for the local weather bureau for the forecast for tomorrow's field-day, there are several services that provide ionospheric predictions. The Australian Space Weather Service, SWS, is one of those. You might have previously known it as the Ionospheric Prediction Service, but Space is much more buzz-word compliant, so SWS is the go. If you're not a radio amateur, space weather can impact stuff here on Earth, like the ability to communicate, transfer energy across the electricity grid, use navigation systems and other life-essentials. The SWS offers alerts for aviation and several other non-amateur services. If you're interested in HF communications, the SWS offers HF prediction tools that allow you to check what frequencies to use to communicate with particular locations using visualisations like the Hourly Area Prediction map. If you're more of the Do-It-Yourself kind of person, you might be pleasantly surprised that you can have your very own ionospheric monitoring station at home. Not only that, it's probably already in place, configured and ready to go. If you're using WSJT-X to monitor WSPR transmissions, then you'll have noticed that the screen shows all the stations you've been able to decode and you can scroll back as far as you like to the time when you launched WSJT-X. If you want to do some analysis on that, copy and paste is an option, but it turns out that there's a handy little document being stored on your computer called ALL_WSPR.TXT that contains the very same data going back to when you installed and launched the first time. This information represents what stations you heard, at what time and with what level of signal to noise at your shack, not some fancy station in the middle of nowhere with specialist hardware, your actual station, the one you use to talk to your friends, with your antenna, your power supply, the whole thing. For my own entertainment I've been working on a way to visualise this. I created a map that shows the location every station I've logged, 30,000 of these reports in the past four months. It's interesting to see that I can hear most of the globe from my shack. Notably absent is South America but that is likely a combination of band selection and local noise. In the meantime I've gone down another rabbit hole in figuring out if I can use an image file to visualise all this without needing fancy software, unless you consider a web-browser and bash fancy. The idea being that a simple script could take the output from your station and convert that into a map you can see on your browser. In case you're wondering, I'm thinking that a style-sheet attached to a Scalable Vector Graphic or SVG might be just the ticket to showing just how many times I've heard a particular grid-square. If you have ideas on what else you might do with this data, get in touch. I'm Onno VK6FLAB

Foundations of Amateur Radio When you start playing with software defined radio, you're likely to begin your journey using something with a display that shows you a lovely waterfall, gives you a way to pick out a frequency, decode it and play it over your speakers all over the house. Likely your first effort involves a local FM radio station. These graphical tools come in many and varied forms available on pretty much anything with a display. Tools like SDR#, cuSDR, fldigi and WSJT-X. That can be immensely satisfying as an experience. Underneath the graphics is software that is essentially translating an antenna voltage to a sound, in much the same way as that happens in an analogue radio. There are the parts that get the signal, then they get translated and filtered, translated some more, decoded, and eventually you have sound coming from your speakers. During the week I caught up with a fellow amateur who pointed me at the work of Andras HA7ILM who for a number of years has been quietly beavering away making various tools in the SDR landscape. One of those tools has the innocuous name of "csdr", a command-line software defined radio digital signal processor. It started life on November 1st, 2014 and has had many updates and community changes since. This tool has no graphics, no user interface, nothing visible that you can toggle with a mouse and yet it's one of the coolest tools I've seen in a long time and from a learning perspective, it's everything you might hope for and then some. Before I explain how it works, I need to tell you about pipes. They're much like water pipes in your home, but in computing they're a tool that allow you to connect two programs together so you can exchange data between them. One of the ways that you can think of a computer is a tool that transforms one type of information into another. This transformation can be trivial, like say adding up numbers, or it can be complex, like filtering out unwanted information. The idea is that you take a stream of data and use a pipe to send it to a program that transforms it in some way, then use another pipe into another program and so on, until the original stream of numbers has become what you need them to be, creating a transformation pipeline with a string of programs that sequentially each do a little thing to the data. That stream of data could be numbers that represent the voltage of the signal at your antenna and the final output could be sound coming from your speaker. If you were to take that example, you could use one tool that knows how to measure voltage, pipe that to a tool that knows how to convert that into FM and pipe that to a tool that knows how to play audio on your speaker. Converting something to FM is, in and of itself, a series of steps. It involves taking the raw numbers, extracting the part of the samples that are the station you want to hear, decoding those and converting that into something that is ready to be played on your speakers. This process is fundamentally different from using a so-called monolithic tool that does everything behind the scenes. The person writing the software has decided what to do, how to do it, in what order and in what way. If you want to do something that the author hadn't thought of, like say listening to a new type of broadcast, you'll be waiting until they update the software. In another way, this is the difference between making a cake from raw ingredients and buying it up the road at the shops One final part of the puzzle. There's nothing preventing you from piping the output of your program to another copy of the same program. So, if you had a tool that knows how to do the maths behind filters, AM and FM decoding, translating Lower Side Band into Upper Side Band and vice-versa, band filtering, etc., you'd be able to set up individual steps that translate a signal, one step at a time, from raw antenna data into a sound you can hear. You would have all the building blocks for the fancy tools that you are used to. csdr is such a tool. For example, it knows how to set the gain of a signal, how to up and down sample, how to shift frequencies, how to decode them, it knows about RTTY, PSK, AM, FM and do about a hundred other things. So far I've mentioned decoding, but there's nothing stopping you from starting with plain text, piping that into csdr and converting that to a PSK31 audio signal and transmitting that audio on your radio. To make it even better, because it's so modular, you can look at the math behind what's going on and begin to understand what's happening behind the scenes. Of all the tools I've found in the past decade, I have to confess, this is the one that has stopped me in my tracks. Thank you to Randall VK6WR for introducing me to this tool and to Andras HA7ILM for writing it. I'm Onno VK6FLAB

Foundations of Amateur Radio In 1958 The Kentucky Engineer published an award winning student article by Copthorne "Coppie" MacDonald. He described a Slow-Scan T.V. System for Image Transmission. If you get the opportunity, have a look for the link on his archived home-page which you can find from the Wikipedia SSTV page. The purpose of this narrow band television idea was to be able to send images using cheaper equipment and less bandwidth than normal television. The idea caught on and it's still in use today. In 1959 the idea of slow scan tv was used by the Luna 3 mission to transmit images from the far side of the moon. The NASA Apollo program also used SSTV to transmit images from Apollo 7, 8, 9 and from the Apollo 11 Lunar Module. In 1968 SSTV became a legal mode for radio amateurs in the United States. The International Space Station regularly uses SSTV to send images to radio amateurs across the globe. The version of SSTV in use by radio amateurs today is different from the earlier grainy black and white images coming from the moon and if you're expecting a moving image, something that TV implies, you're going to be disappointed, since the popular SSTV modes send images one at a time, taking up to a minute or so to send. With a frame-rate of one frame per minute, watching anything other than grass grow is going to be a challenge. That said, SSTV is a lovely and relatively simple way of sending images across the air. In my quest for new adventures I like to play with things I know nothing about. I suspect that it's ingrained but it does keep me off the street. The other day I received an email from a local amateur, Adrian VK6XAM, who sent a message describing a new SSTV repeater he'd set-up for testing purposes. It's a local 2m repeater that waits for an activation tone, then it expects you to transmit an SSTV image and it will replay the image back to you. If you've familiar with a parrot repeater, this is a similar thing, just for SSTV rather than audio. The repeater is running on solar power and with the 100% duty cycle of SSTV, it's only available during daylight hours. Technicalities aside, I couldn't resist. So, I fired up QSSTV, a piece of Linux software that among other things knows how to receive and send SSTV images. After turning on my radio, tuning to the correct frequency, I received my first ever SSTV picture. On a bright red background a yellow symbol appeared. At first I thought it was a hammer and sickle, but on closer inspection it was a micrometer and caliper, which absolutely tickled my fancy, having just taken delivery of some precision measuring tools - a Mitutoyo Test Indicator and a few other bits and pieces for another project I'm working on. Had to learn how to drive QSSTV, make a template so you can overlay text on an image, learn what a signal report should look like, then when I figured all that out I triumphantly hit send and it made all the right noises, but nothing was happening. More time looking at the inter-web taught me that if I want to use the rear connection on my FT-857d to send audio using FM, as opposed to SSB which is what most digital modes need, you need to set the radio to PSK mode and magically it starts to work. My first ever SSTV image was sent an hour and a half after receiving my first image and the repeater dutifully sent it back. Then I got a picture from Keith VK6WK. Of course the paint isn't even dry on any of this, so there's plenty more to learn, but the process is not too complex. I will note a few things. I had already set-up digital modes, that is, my radio was talking to my computer via CAT, that's Computer Assisted Tuning, essentially a serial connection that controls the radio and the audio was already being sent and received from the rear connector of my radio. Getting SSTV running was really an extension on those activities, so if you're going to do this, take some time to make things work. I continue to recommend that you start with WSJT-X since it helps you get your levels and connections right. Now I suppose I should start playing with SSTV over HF, but first I would like to figure out how to make the templates work better for me and how to actually seriously log an actual contact. More adventures ahead! Remember, have fun, play, get on air and make noise! I'm Onno VK6FLAB

Foundations of Amateur Radio My radio shack consists of two radios, identical, well, in as much as that they're the same model, a Yaesu FT-857d. Their memories are different, their microphones are different, but both of them are connected via a coaxial switch to the same VHF and UHF antenna. One of them is also connected to a HF antenna. Let's call these two radios alpha and bravo. Alpha is used to host F-troop and play on the local repeater. Bravo is used to do HF stuff. It's also connected to a computer via a serial cable, called a CAT cable, Computer Assisted Tuning, but really, a way to control the radio remotely. The audio output on the rear of the radio is also connected to the computer. These two connections are combined to provide me with access to digital modes like PSK31, WSPR and SSTV, though I haven't actually yet made that work. The computer itself is running Linux and depending on what I'm doing on the radio some or other software, often it's fldigi, a cross-platform tool that knows about many different digital modes. The computer is also connected to the Internet via Wi-Fi, and is used to see what various reporting websites have to say about my station, things like propagation, the DX cluster, an electronic way of seeing what other stations can hear, then there's solar radiation information and other neat tools. This shack is pretty typical in my circle of friends. I'm lucky enough to have a dedicated table with my shack on it, for others they're lucky to have a shelf in a cupboard, or at the other end of the spectrum, a whole room or building dedicated to the task. The level of complexity associated with this set-up is not extreme, let's call it in the middle of the range of things you can add to the system to add complexity. In case you're wondering, you might consider automatic antenna switching, band switches, band filters, amplifiers, more radios, audio switching, automatic voice keyers. If you look at the world of Software Defined Radio, the hardware might include many of those things and then add a computer that's actually doing all the signal processing, making life even more complex. At the other end of the complexity scale there's a crystal radio. As I've been growing into this field of amateur radio it's becoming increasingly clear that we as a community, by enlarge, are heading towards maximum complexity. There's nothing wrong with that as such, but as a QRP, or low-power operator, I often set-up my radio in a temporary setting like a car or a camp site. Complexity in the field is not to be sneezed at and I've lost count of the number of times where complexity has caused me to go off-air. It occurred to me that it would be helpful to investigate a little bit more just what's possible at the other end of the scale, at the simple end of complexity if you like. So, I'm intending, before the year is out, supplies permitting, to build a crystal radio from scratch. I realise that I have absolutely no idea what I'm getting myself into, no doubt there will be more complexity that I'm anticipating, but I'm getting myself ready to build something to be able to look at it and say to myself, look, this is how simple you can get with radio. I'm currently too chicken to commit to making the simplest - legal - transmitter, but if you have suggestions, I'll look into it. Just so you know, simplicity is an option. I'm Onno VK6FLAB

Foundations of Amateur Radio Yak Shaving ... Not every adventure gives you an outcome. Today started with reading a thank-you email from a listener who shared their activities and wanted to express their gratitude for encouraging them to get on air and make noise. That in turn prompted the question on the country of origin of that listener and did I know where all my listeners were? For the past few hours I've been attempting to answer that seemingly simple question. Aside from using the opportunity to make an attempt at mapping the distribution of amateurs in Australia, which on the face of it is a trivial exercise, consisting of extracting the postcode from each registered amateur and then putting those on a map. Only the postcodes are not actually single points. They're boundaries defined by Australia Post and they're copyrighted. Not only that, they change. To access them, you have to pay the Post Office. If you want to combine a postcode with a population density, so you can see where amateurs are represented and at what level, you go to the Australian Bureau of Statistics for a population density data-set. At that point you realise that the Bureau uses standardised regions. Mesh-blocks at the smallest end of the scale are essentially the size of 30 to 60 households. The Bureau uses these as the fundamental size for all its statistics. When you attempt to map this onto postcodes you learn that there isn't a one-to-one mapping and even if there was, it would change every time Australia Post changed a postcode boundary. I will note that this is all by way of a side-street in my investigation. I wondered how amateur radio is distributed across the country and I didn't want to end up with essentially a population density map, more people means more amateurs, I wanted to see where amateur radio had the potential to affect more people because there are more of them in a group. Anyway, then I attempted to look at the podcast downloads and map those to countries. I use AWS CloudFront to make the podcast available, so it gets to the user, you, quicker. The logs show which data-centre a request is handled by. Then I needed to map a data-centre to an airport code, look that up in a database so I could extract the country, then count how many requests were made per country. Then I started doing that across time, so you can see how that changes over time. At this point I still don't actually have a map to show. While all this was happening, my computer started running low on disk-space, not because I'd just downloaded some data from the Australian Bureau of Statistics, but because some rogue process was writing a log somewhere, so I spent an hour looking for what process that was, killing it and removing the superfluous log file. If this sounds familiar, there's a name for it. Yak shaving. It's originally named after a Ren and Stimpy episode called "Yak Shaving Day". Essentially you do a whole lot of unrelated activities in the pursuit of the actual activity, essentially a string of dependencies that distract you from the end-goal. In my case, trying to answer which countries are represented within my audience. Why am I not using an amateur radio example? Two reasons. This is amateur radio. For me. Doing charts, wrangling data, massaging stats, finding answers and presenting those are an integral part of the hobby, to me. Just like making this podcast, contributing to discussion, reading and learning. All part of the mix. Second reason is that I wanted to illustrate this with something that wasn't immediately obviously linked to the hobby for most people. A more amateur example might be wanting to go and operate portable, attempting to locate you battery, when you find that it's not charged, so you go looking for the charger which you find has a broken connector, so you drive to the electronics store to get the connector when you run out of petrol, so you pull over, get out of the car and trip over the curb and end up in hospital emergency waiting for a doctor to see you. If you think that's far-fetched, I know an amateur who ended up in hospital from yak-shaving. We've all had days like that. The idea is that any day that you are on the right side of the earth, doing something you love is a good day. Regardless of the end result, this is a hobby after all. I'm Onno VK6FLAB

Foundations of Amateur Radio In my ongoing software explorations I've discussed that Software Defined Radio or SDR is a fundamentally different way of dealing with radio. It's been in use across non-amateur circles for decades. Your mobile phone has an SDR on board for example. The original term of "digital receiver" was coined in 1970, "software radio" was coined in 1984 and in 1991 Joe Mitola reinvented the term "software radio" for a planned mobile phone base station. So, this idea has been around for half a century and in amateur radio this idea is also catching on. You can buy a few pure SDR devices today, some hybrid ones, or you can begin to experiment in a more indirect manner using your traditional radio and a computer. One of the things that sets this idea of a software defined radio apart from anything we've done so far is that the bulk of the signal processing is done in software. That sounds obvious, but it's really not. One of the impacts of this idea is that you can improve your radio communications by either writing better software, or by using a faster computer. Unless you write software for a living, these things aren't immediately obvious, so let me explain. Imagine that you've written software that detects beeps in a particular slice of audio spectrum that's being fed to your application. As you write better software to detect those beeps, you get a better digital mode, one with a better chance of being decoded, or using radio terms, it has a better signal to noise ratio. If that's not a familiar term, signal to noise ratio is the a measure that describes the difference between a wanted signal and the background noise. Higher signal to noise means that you can better distinguish between the two. If you stand in a room full of people talking and you use your hands to cup your ears towards the person you want to hear, you've increased the signal to noise ratio and your chance of understanding them has improved. As you write this software, it gains complexity. As you deal with more maths, more samples, more tests, you end up running out of time to make your decoder return a relevant answer. There's no point in having a real-time signal being decoded late. If it were to take say 10 seconds to decode 1 second of audio, then the next second would be 20 seconds late and the one after that would be 30 seconds late. That's where a faster computer comes in. If you have the ability to do more maths, or do the same maths at a higher resolution, you will essentially improve the reception of your radio without ever needing to change your antenna or anything on the circuit board. Think of it in another way. Imagine that your tool has access to 2.3 kHz of audio. It's the equivalent of a Single Side Band audio stream. If you break that down into 23 chunks of 100 Hz each, you can deal with the average of 100 Hz of audio for each calculation. If you have a faster computer, you might be able to break that down into 230 chunks of 10 Hz each, or 2300 chunks of 1 Hz. So instead of doing calculations across 23 chunks of audio, you're doing it across 2300 chunks. Why is this significant you might ask? Well, in a traditional radio you get one bite at the cookie. You get to design and build your circuit and then package it and sell it. The end result is something like my FT-857d. It does what it does well, but it will never get any better. However, if I plug that same radio into my computer, I can extract the audio and do stuff with it. If I get a faster computer, I can do more stuff. I don't have to change my radio, or my antenna, or even my shack. Most of the time I run a different application and I get a different result. I will point out that I'm deliberately ignoring where and how the RF gets to the computer, or where that computer actually is, or what operating system it's running, since none of those things matter to get an understanding of how changing software can change the performance of your radio. I've said this before and I'll say it again: "The SDR earthquake will change our hobby forever" Before I go. I'm not for a minute suggesting that your current radio is obsolete. If it were legal, a spark-gap transmitter could still exchange information today, but if you want to explore what might be just over the horizon, going down the SDR path by connecting your radio to your computer is a really nice place to start. I'm Onno VK6FLAB

Foundations of Amateur Radio Contesting is a fun way to learn about amateur radio. It tests your skill, your station, your patience and your ability to change approach at a moments notice. For those reasons alone it's an activity that I recommend you have a go at. For me it's also about self-improvement. With each contest, can you make better use of your station, can you learn more about your radio, about bands, about conditions and ultimately become a better operator. I know that there are individuals who keep telling me that giving out signal reports of 5 and 9 isn't helpful, to them I say, try it in a contest setting and see what else you learn. When you start out contesting you'll quickly come across two terms, technically three, that need some explanation. The terms are Run, Search and Pounce, though the last two come as a matched pair. The essential bit of information is that when you're on a Run, or Running, you're calling CQ and responding to other stations. You essentially sit on a frequency for a bit, start calling CQ and hope that others hear you and start to gather around to make contact with you. The other side of that is Search and Pounce, or searching on a band for a station you want to talk to and pouncing into a gap when you can. The two methods are mirror images of each other, so one station is generally running whilst the stations calling in are searching and pouncing. Doing this in a contest setting requires slightly, some might say subtle, differences. Let's investigate a contest RTTY contact. I'll simulate it between myself, VK6FLAB and Matt, VK6QS. I'll add that this is done in text in a RTTY contest, rather than voice, and, this exact exchange didn't actually happen, but for different reasons which I'll get into shortly. It goes a little like this. My station transmits: CQ TEST VK6FLAB VK6FLAB CQ Matt responds: VK6QS VK6QS VK6QS I reply: VK6QS 599 010 010 Matt replies: 599 032 032 And I finish off with: TU CQ VK6FLAB Now this is the ideal contact, nothing extraneous, no duplication, nothing about having to repeat yourself. Mind you, if you're getting picky, you might notice that we're both sending our exchange twice, in my case 010, Matt is sending 032. If you look closer you'll notice that all pertinent information is sent at least twice because it turns out that unlike a keyboard on a computer connected to a screen, what you type in RTTY might not actually get to the other end if you're using HF radio. My three transmissions are the one where I call CQ, the one where I say Matt's callsign plus the exchange and the one where I say TU or Thank You, and move on. Those are the run calls. Matt's calls consist of his callsign, and his exchange. Note that Matt doesn't say my callsign, since I already know it and I'm running and he's searching and pouncing. He should already know who I am before he transmits. If he were to add my callsign, that would just slow things down. This is a way to keep things moving along. In fldigi, I can program a function key that does each of those five calls. You click on a callsign, push the appropriate button and magically you're either running or pouncing. There's also a button for asking for a repeat, or "AGN?, AGN?" and one for making a log entry, which you can combine into the final thank you for running, but it's needed separately if you're pouncing. I did say that this exchange didn't actually happen and you might well wonder why I shared it with you. Simple. This is the bare-bones of what's required. Everything else is extra in case things break down. If there are multiple stations on the same frequency, or if your levels aren't quite right and the decoder is having a hissy fit, the human in the chain, you, need to do something manually. Very much like when you're dealing with a voice pile-up and there's this one station calling over the top of everyone else and drowning out whomever you actually want to talk to. In a contest setting there's plenty of opportunity to do both running and pouncing and you should. If you're running on a dead band you won't know because you're getting old calling CQ, but if you're searching on that same band you'll figure out pretty quick that there's nothing happening. Similarly, you might have a desirable callsign or location and find that running is more effective in making contacts than searching and pouncing. Whatever mode of contesting you choose, make sure that you're flexible, since band conditions change from second to second and you will need to adapt to the winds of change. A lot like when you learn to sail and find out that you cannot just hold the helm in one spot for the entire time. I will note that the ideal RTTY contact that I've outlined isn't universal. There's plenty of debate about the most effective way to go about things. I started with what I knew about making voice contacts, shamelessly copied the RTTY macros from another amateur and used them as a basis to learn what I needed and what I didn't, a

Foundations of Amateur Radio It's the morning after the day before. I've been calling CQ for 24 hours and for the first time in my life after a contest I still have my voice. That in and of itself is novel. I also don't have ringing ears, that's a blessing. I have learnt heaps and had fun doing it. I made contacts and I heard stations across the globe and I did it all from the comfort of my shack chair. Before I dig in and expand, the contest I just completed ran for 24 hours. I didn't sit at my radio for all of it, nor was my radio on for all of it. I managed to have lunch, dinner, desert, breakfast and morning tea. I snuck in a few naps and I managed to help with bringing in the shopping. My station did not transmit unattended at any time in case you're wondering. My setup consisted of a little 11 year old netbook computer running the current version of Debian Linux and the heart of this adventure, the software called fldigi. The computer is connected to my Yaesu FT-857d via three cables, well, two and a half. A microphone and a headphone lead that combine into the data port in the back of the radio. The other cable is a USB CAT cable, a Computer Assisted Tuning cable, that plugs into the CAT port on the back of the radio. I also used an external monitor to have my main contest screen on and used it to display the main fldigi window. My license class allows me access to a selected number of amateur bands, 80m, 40m, 15m, 10m, 2m and 70cm. I managed at least one RTTY contact on each band. As I described previously, my radio is set to use Single Side Band and the audio from the radio is fed via the microphone socket on the computer into fldigi that processes the information. Similarly, when I transmit, the audio is generated via fldigi and leaves the computer via the headphone socket and goes into the radio as a Single Side Band audio signal. The information in the audio is all RTTY, a digital mode that I've described previously. The software is using Audio Frequency Shift Keying, AFSK, simulating the switching between the two RTTY frequencies. On my screen I have a waterfall display that shows all the signals that are happening within the 2.3 kHz audio stream that's coming from the radio. Fldigi is also decoding this in real-time and showing each decode as a virtual channel in a list. Click on a channel entry and your next transmission will happen at that frequency. If you've ever used WSJT-X this will sound very familiar. That's the mechanics of what I've been doing. So, what did I learn in this adventure? Well, most of Australia goes to sleep at night, at least the ones that do RTTY. I have evidence of exactly one station on-air, and that was only because they were named in the DX Cluster, which by the way this contest allows as assistance. Since then I've found logs from at least two more stations. Local contacts did happen during the more civil hours and in total I managed ten of them. You may think that's not much for say 12 hours of work, but that's 5 Watts QRP, or low power, RTTY contacts, in an actual contest, on a new antenna, from my shack, dodging thunderstorms and learning to use filters and levels. You might not be impressed, but I'm absolutely stoked! During the midnight-to-dawn run, on 40m, when there were double points to be had, which I missed out on, I did manage to hear several stations across Europe, 14,000 km away, which means that I can pretty much count on global coverage with my current setup. Sadly they didn't hear me, too many competing stations, but I'm sure that with practice I'll manage to contact them too. The software crashed once. That's not nice. It seems to have a habit of corrupting one of the preference files, which prevents it from starting up. That's also not nice. I hasten to add that I don't yet know the source of this. It may well be a dud-hard-disk sector on my ancient laptop, rather than the software, so I'm not assigning blame here. Getting started with fldigi is an adventure. It's not point-and-click, nor plug-and-play, more like running a mainframe whilst cranking the handle, but when you get it to fly there's lots to love about this tool. Other things that worked well were that I'd spent some preparation time getting the keyboard macros right. These are pre-defined bits of text that you send as you're calling CQ and making a contact. They're a whole topic in and of themselves, so I'll skip past the detail and just mention that I was very happy with the choices I made, gathered from years of voice-only contacts, reading RTTY contest information and looking for exchange details. From a technical perspective, I used both contest modes, "Running" and "Search and Pounce". Running is when you call CQ, Pouncing is when they call CQ. The running was by far the most successful for me. I'm not yet sure if that was a reflection on how much I still have to learn about levels. One thing that I can say with confidence is that there's absolutely nothing like having a wall of

Foundations of Amateur Radio When you start playing with radio your first interaction is likely to be voice. It could be SSB, AM, FM or something more recent like FreeDV or DMR. Your next challenge is likely going to be a digital mode like Morse Code, Radio Teletype or my recommendation for your first adventure, WSPR or Weak Signal Propagation Reporter. I've previously discussed WSPR, today I would like to look at Radio Teletype or RTTY. It's a digital mode that allows you to send and receive free-form text. It's a mode with a long and illustrious history and it's a good next step after WSPR. The way it works is that using an alphabet made up from two tones, information is transmitted, one character at a time at a specific speed. The code that describes the alphabet is called the Baudot code, invented by Jean-Maurice-Emile Baudot in 1849. In computing terms it's a 5-bit alphabet and in amateur radio it's traditionally sent at 45.45 baud or bits per second, in case you're wondering, named after the very same man. The two tones have names, a Mark and a Space and they're a set distance apart. In amateur radio, they're separated by 170 Hz but there are plenty of other frequencies and speeds in use. In amateur radio the standard Mark and Space frequencies are 2125 Hz and 2295 Hz. In a traditional RTTY capable radio the two tones are generated by transmitting a carrier whilst switching the transmitter frequency back and forth, called Frequency Shift Keying or FSK. Think of it as having a Morse key that sends dits on one frequency and dahs on another, having the radio change frequency whilst you're keying. If you use this method to create and decode RTTY by switching between two frequencies, your radio can generally only deal with one RTTY signal at a time, just the one you're sending and just the one that's being received. Receiving is generally achieved by showing some indication on your radio how close you are to the Mark and Space frequencies that you're trying to receive and decode. Another way to make a RTTY signal is to use sound. If you alternately whistle at 2125 Hz and 2295 Hz and you do it at 45.45 bits per second, you're also generating RTTY. This technique is called Audio Frequency Shift Keying or AFSK. Think of it as using audio to simulate the shifting of frequency by transmitting two alternating tones. There is a fundamental difference between the two. Before I explain, permit a diversion. It's relevant, I promise. If you've ever spoken on the radio using SSB you might have noticed that if two stations are transmitting at the same time you get both signals. With a little practice you can even understand both. This isn't true for every radio mode. If you use FM, the strongest signal wins and if you use AM, you get a garbled beep from two stations being on slightly different frequencies. As an aside, this is why aviation uses AM, so any station not transmitting can hear that two stations doubled up. Back to RTTY. If you use audio to generate the two RTTY carriers, rather than shift frequency, you can deal with as many as you can fit into an SSB audio signal, as long as the Mark and Space for each station are 170 Hz apart you can have as many stations as you want, overlapping even. As long as your software knows what to do with that, you'll be able to decode each one at the same time, since they're essentially multiple SSB signals being transmitted simultaneously. An added bonus is that you don't have to invest in an SDR to play with this. You can use an analogue radio, like my FT-857d, and use software to generate an audio RTTY signal with all the benefits I've just mentioned. The magic is in the software you use to do the decoding. As it happens, I'm about to do a contest using RTTY and I'll let you know how that goes using my radio, a computer and a piece of software called fldigi. I'll be following in the footsteps of the first ever RTTY contest, held in the last weekend of October in 1953 and organised by the RTTY Society of Southern California. In as much as I'm following in the footsteps of Morse code by spark-gap. Wish me luck. I'm Onno VK6FLAB

Foundations of Amateur Radio When I came across amateur radio nearly a decade ago I did a course, passed my test and got licensed. At that point I didn't have any equipment, didn't know about any, hadn't touched anything, other than the radio in the classroom, and had no idea about what to buy and how to choose. So, instead I asked the friend who introduced me to the hobby, Meg, at the time VK6LUX, what radio to get. I asked her what was the second radio she ever got because I figured that I'd get very disappointed with the first one in short order. She explained that there were plenty of brands to choose from and that each had their own champions. Just like the perennial choice between Ford and Chevrolet, Apple vs Microsoft, Tea vs Coffee, you'd end up with one radio and be told by someone in a different camp that you chose the wrong one. Her advice, which is just as solid today as it was a decade ago, was to buy something that people you knew had, so whilst you're learning there'd be someone nearby who could help. As a result I bought a Yaesu FT-857d for precisely that reason. I still have it and it has a sister, another FT-857d, bought when I needed to broadcast the local news when one of the local volunteers went on holiday. For most beginners their journey is similar. They buy their first radio and generally that sets the tone for what comes next. In the decade that I've been around amateur radio I've had the opportunity to play with about 30 or so different radios. For some that playing consisted of picking up the microphone and making a QSO, a contact, and not much else. For others it consisted of sitting with the radio for a full contest, 48 hours, with sporadic sleep, dealing with pile-ups where there wasn't time to breathe, but plenty of stuff to learn about filtering. Then there were the radios that came to my shack for a visit, those at various clubs and plenty of outings where I was able to sit down and figure out how stuff works. On the surface that's all fine and dandy. A radio is a radio, you pick up the microphone and hit go, off to the races. Then you need to figure out how to set the volume, change frequency, change bands, read what the mode is and how to change it, tune the thing, set up a filter, change the pre-amp, operate split. For some radios this was easy, consisting of a channel button and a microphone push to talk, for others there were no buttons, just a big Ethernet socket, then there were the radios with a hundred buttons, some so small that you missed them on first glance. I've used solid-state radios, valve radios, software defined radios and virtual radios, each with their quirks and idiosyncrasies. Every time I operate a new radio I learn something about that radio, but I also learn something about my own radio. I can begin to hear differences, observe how easy or hard it is to do something, a missing feature on my own radio, or the one I happen to be operating at the time. In my travels I've seen plenty of radio amateurs who only have a passing understanding of their own radio, let alone any other radio. I completely respect that this might be enough for you, but I'd like to point out that this might be a missed opportunity. I remember vividly sitting in the middle of a bush-camp with my own radio powered by a battery connected to a hap-hazard dipole antenna strung between two trees attempting to hear a station discussing her global circumnavigation by sailing boat and being frustrated with my ability to make it work. A friend who was sitting nearby asked if they could have a go and within seconds he was able to use the filters and offsets to make the station pop out of the noise. It's with the image of Kim VK6TQ in mind, the person who knew my radio better than I did, that I'd like to urge you to play with any radio you come across, no matter how trivial or different. One day it will mean the difference between making a contact or not. I'm Onno VK6FLAB

Foundations of Amateur Radio The other day day I managed my first DX contact using a new mode, FT8. It wasn't very far away, all of 2600 km or so, but it evoked memories of my first ever on-air DX contact nearly a decade ago. I should say thank you to YD3YOG for my 15m contact, fitting because my first ever was also on 15m as I recall. Unfortunately I never did log my first. Recently a friend asked me how the two compared. 15m and logging aside, there's a lot of similarities, even though I'm a more experienced operator today when compared to when I made my first ever contact. The preparation and the building anticipation is what made the contact all the sweeter. A while ago I managed to connect the audio of my radio to a computer. This is pretty much the first step in starting to use digital modes. Essentially many common digital modes use an SSB transmission to generate and receive audio that in turn contains digitally encoded information. There are hundreds of modes like this, from PSK31 to RTTY, WSPR, FT8, SSTV and many more. If you've not yet dabbled in this area, I'd recommend starting with WSJT-X. The software is so far the best tool I've found to make sure that your digital levels are correct and offers several popular modes to see how your station is operating. If you're asking for a first mode recommendation, I'd start with WSPR. Just do the receive part first, then work on from there. There are many tutorials available, some better than others, so if the one you find doesn't float your boat, keep looking. A fly-over view is that there are several things that you need to get working and if they don't all work together, you'll get no result. Obviously you'll need to install the software, but that's not the whole story. For the software to be able to control your radio, change bands, frequency and set-up things like split operation, you'll need to set-up the hardware to do this, in my case a CAT cable between the radio and the computer. You'll also need to set-up control software that knows how to talk to the hardware. In my case that's Hamlib on Linux, but it could be Hamlib or flrig on MacOS or something like OmniRig on your Windows machine. The purpose is to control the radio. When you're troubleshooting, keep that in mind, hardware plus software need to work together to control the radio and this is before you actually do anything useful with the radio. Then you need to have both hardware and software to have audio go between the computer and the radio. In my case the headphone and microphone connectors on my computer are connected to the data port on the back of the radio. If your computer doesn't have access to sockets you might need to use a USB sound-card. If your radio doesn't have an easily accessible port, you might need to have an interface. The computer software in this case is likely setting the volume levels using the audio mixer in your operating system. I will add that some radios have a USB socket on the back that combines both CAT control and audio. The principle though is the same. You need to make the CAT interface work, which is essentially a serial connection, and you need to make the audio work, which is essentially a sound-card. Nothing else will make sense until you've managed to make those two work. Then, and only then, can you try to launch something like WSJT-X, point it at the various things you've configured, then you can actually start decoding signals. For WSJT-X to work properly, there's one more thing. An accurate clock is required. Likely you'll need to use a piece of software that knows how to synchronise with something called NTP or Network Time Protocol. The simplest is to point your clock tool at a time-server called pool.ntp.org which will get you global time coverage. Each operating system does this differently, but getting it right is essential before WSJT-X will actually make sense. You can visit time.is in a web browser to see how accurate your clock currently is. So, get computer control of your radio working, get audio working, set the clock, then you can run WSPR, FT8, JT65 or any other mode. I will note that I'm not attempting to give you specific computer support here, just an overview of what's needed before anything will work. If you've been contesting then CAT control might already be operational. If you've been using a computer voice-keyer, then audio might also be ready. Depending on where you are on your digital journey, these steps might be complicated or trivial. Once you've done all that you can start doing things like figuring out where satellites are or how to talk to the International Space Station, or use Fldigi to make a PSK31 contact or send a picture using SSTV or decode a weather fax. When you've made that first digital DX contact, I'm sure that you too will have a sense of accomplishment! I'm Onno VK6FLAB

Foundations of Amateur Radio When was the last time you told anyone anything about your hobby? What about someone who isn't also an amateur? Have you ever considered why there is a perception that our hobby is dying, why it's running out of people, why we struggle to get air-time in mainstream media, why attracting new members is hard and why there is a very narrow range of understanding about what our hobby is, what it does and how it's relevant in the world today? I'm a radio amateur. So are you. You might not be licensed yet, but the fact that you're here right now indicates a willingness to understand and learn, to participate and question. Those qualities are the fundamental building blocks that make up a radio amateur. I'm also a self-employed computer consultant, a radio broadcaster, an interviewer, a software developer, a public speaker, a blogger, author, publisher and a partner. My friends include people who are process managers, astronomers, gynaecologists, mariners, tow truck drivers, communications technicians, volunteer fire-fighters, business owners, employees, retirees, fathers, mothers, old, young and everything in between. Radio Amateurs one and all. When you sign up to be an amateur, you don't give up all the other things you are. You don't stop being a member of society, you just add in another box marked radio amateur and you get on with your life. If you get into this hobby you begin to realise that it sneaks into everyday life all the time. You use it to figure out how something works, or explain why it doesn't, you use it to trace a circuit or to plug in your new surround sound system. You use it to encourage curiosity in your children and to talk to your grand-children. It's not an add-on, it's part of who you are. That's always been the case, but the perception in the general public has not been like that, it's been based around the idea that being a radio amateur is being special, being separate, being knowledgeable, studied, licensed. The reality is that the world we live in is more connected than ever and the things we once did in isolation are now part of mainstream life. There is a perception that amateur radio is dying. Articles describe how we need to attract more people, how we need to appeal to children, how we need to recruit, become sexy or relevant. There's discussion about what's broken in the hobby, how we need to fix it. I think that none of those things are what's in need of investigation. I think it's us. You and I. I think we need to stop being shy about being a radio amateur, about what we do and why we enjoy it; what it means and how it works. When you talk about your activities of the day, if you made a rare contact with Tuvalu, or managed to connect your computer to your radio, or made an antenna work, or climbed on a hill or learnt Morse Code, you need to share your victories and the excitement that they bring you. As a society we're not shy about tweeting what we had for breakfast, sharing an interesting picture or discussing an article we saw on reddit. Fundamentally what you do and who you are is worth talking about and sharing. So, next time you talk about going camping, or discuss a barbecue you had with friends, or relate to your friends something that happened, don't be shy about your amateur radio affiliation. It's not a secret society, it's not weird or embarrassing, it's just part of what makes you who you are. I'm Onno VK6FLAB