Foundations of Amateur Radio

Foundations of Amateur Radio The thing I love most about this amazing hobby of amateur radio is the sheer size of the community and the depth of knowledge that comes with it. Case in point, the other day I mentioned the spark gap transmitter at Grimeton in Sweden. A few hours after releasing my comments into the void I received a message from Paul SA7CND who lives, wait for it, 153 km from the transmitter. He's been on-site while it was running, transmitting on 17.2 kHz. Paul pointed out that the Grimeton transmitter is not a spark gap transmitter at all. It's actually an Alexanderson alternator, an entirely different beast, and all the more interesting for it. Invented by Swedish electrical engineer and inventor, Ernst Frederick Werner Alexanderson, he received a patent for it in 1911 whilst working for General Electric. He died in 1975, aged 97 with 345 patents to his name. Before I dig in, because you know I will, the transmitter at Grimeton was officially opened on the 1st of December in 1924. Built to increase Swedish independence after World War I revealed its vulnerability to foreign controlled transatlantic telegraph cables. Serving as a telegraphy station capable of transmitting traffic across the Atlantic ocean the station was in regular service until 1996. Unlike its scrapped brethren, the Grimeton transmitter is currently operated several times a year as a functioning transmitter using the callsign SAQ. Announcements are made on the station mailing list and the website at grimeton.org, but generally on Alexanderson Day in July and Christmas Eve in December. You'll need to tune to 17.2 kHz, something you can do with a sound-card, or with an SDR. Sound-card you say? Yes. Not for audio, but for RF. Connect an antenna to the microphone centre-pin input and have at it. Note that this will likely be highly susceptible to noise, so filtering and experimentation are to be expected. There's several tools around to play with this, GNU Radio, Quisk, SuperSID and SAQrx. Also, there's plenty of other VLF, or Very Low Frequency stations to listen to. I should probably add this as a 51st thing to do with SDR, but I digress. Back to Grimeton. As the last remaining functional Alexanderson alternator transmitter, it was added to the UNESCO World Heritage List in 2004. You can visit and see first hand what radio history looks like. As I said, if you pick your day, you can even watch it working. Failing that, there's plenty of YouTube videos showing the entire process, it's an absolute monster. There's even an amateur radio shack on-site with the callsign SK6SAQ. The website says that it's open sporadically, so I'd recommend you contact them before heading to Grimeton. I'll note that at the time that this station was being commissioned in 1924, it was already being superseded by valve oscillators, which brings me to how it works. Depending on where you live, you're likely familiar with the 50 or 60 Hz alternating current associated with household electricity. In 1891, Irish experimental physicist Frederick Thomas Trouton pointed out that if you could run an alternator at high enough speed it would create an alternating current at radio frequencies, said differently, creating a continuous wave at radio frequencies. Much experimentation followed and many giant shoulders supported this effort. It goes a little like this. Use an electric motor designed to spin at 900 revolutions per minute. Connect it to a gearbox. Connect that to a rotor with multiple poles. Then run the motor with a clutch to vary the speed. If that's not enough, to produce high power, the clearances between rotor and stator have to be kept to a millimetre. Then there is cooling and lubrication to consider, not to mention dealing with thermal expansion and contraction of a fast spinning and closely toleranced disk. At Grimeton, the whole transmitter weighs in at 50 tonnes, pretty much the opposite of portable operation. The rotor at Grimeton is a 1.6 meter diameter disc with a 7.5 cm thick edge with 488 slots milled into it, each filled with brass. The motor at Grimeton runs at just over 711.3 revolutions per minute, the gearbox has a ratio of 2.973 and the whole contraption generates 17,200 Hz. If you get the sense that you're balancing an elephant on top of a needle, you're almost there, but if you consider that keying the transmitter changes the load and currents, it's more like an elephant being shoved by a train, balancing on top of a needle. At Grimeton, the motor is loaded by one of three liquid resistors, which each consist of a two metre high container filled with water and baking soda. The liquid level is controlled by separate pumps, varying the resistance. Whilst transmitting, a second liquid resistor is added, reducing the resistance to regulate the speed of the motor to maintain the overall speed and the associated frequency. The resistors generate heat which is fed through a heat exchange to the station's water cooling system. The thir

Foundations of Amateur Radio The other day I was playing around with RDS, or Radio Data System, it's a digital signal that's often embedded in a commercial broadcast FM transmission. Among other things it contains information about the station, its content, frequencies and potentially other useful information, such as traffic alerts. If you recall I've been working on 50 things to do with a Software Defined Radio and decoding RDS is one of those things. The decoding effort aside, I imagined a screen where you could see the RDS information, in real-time, as it was being transmitted by all the local FM broadcast stations. You'd see what music each station was playing, what their local clock thought the time was, how much they transmit other data and what they might do for emergencies, like say a Tropical Cyclone heading this way. It occurred to me that this would be an example of a fundamental difference between a traditional radio and a Software Defined Radio or SDR. Specifically, we're taught that you tune a radio to a frequency, it demodulates or decodes what's there and plays the sound, or digital information, or whatever is being transmitted, on that frequency. If you want to hear something else, you need to change frequency and the radio decodes that new frequency. If you have multiple channels to choose from, there are ways to automatically switch frequency, one after the other. One of my friends recently discovered an old scanner in a box and according to the specifications, it can scan 20 stations per second. If all 1,000 stations are programmed, it takes 50 seconds to scan them all. A lot can happen in that time. The traditional solution is having more radios. Ideally you'd have one for every frequency you care about. Cost aside, logistically this is not fun. Imagine having to power a thousand radios, or find the one where the volume isn't right, or even find space for them, or antennas. In the SDR world that's not quite how it works. Instead of tuning to one frequency, you essentially tune to a range of frequencies and then, using software, decode one or more of those frequencies, at the same time. Listening to multiple broadcast FM stations like that might not make a whole lot of sense, but what about decoding RDS, or listening to aviation frequencies, or local amateur radio repeaters, or multiple digital modes? While that might sound far fetched, a $50 RTL-SDR dongle can manage 2.5 MHz of bandwidth over USB, by comparison, my $1,000 Yaesu FT-857d can receive all of 200 kHz in Wideband FM mode, and only whilst tuned to the broadcast band frequencies. In normal AM or FM mode it's 10 kHz, so you'd need 250 of them to listen to the same frequency range. Again, just so we're clear, in analogue radio you need to change frequency to decode a different signal. In SDR you can simultaneously decode as many signals as resources permit. For example, I can make a simple GNU Radio flowgraph, a little program, that accepts a command line setting, in GNU Radio it's called a parameter block, and run it with a frequency I'm interested in. Then I can run another copy of the same program with a different frequency. Rinse and repeat and I have as many receivers as I need. While we're at it, you don't need to run the same program multiple times, you can run an FM decoder, a RTTY decoder, an AM decoder, all at the same time, as long as the frequencies you're looking at fit inside the bandwidth of the receiver you're playing with. Just so we're clear, this is one receiver, one antenna, one power supply, with as many decoders as resources allow. In other words, these two methods, analogue and SDR, are not the same. Am I glossing over things? Sure. With such a wide bandwidth comes susceptibility to interference and signal overload, also the RTL-SDR dongle doesn't transmit, although, in 2014 Ismo OH2FTG managed to change the centre frequency of his dongle 300 times per second, causing the on board oscillator to leak in a controlled manner, making a Frequency Shift Keyed or FSK transmission. Yes, I know, that's not quite up to the standard of a transmission coming from an 857d. You'll also need a computer, which you don't need to run an analogue radio, though truth be told, an analogue radio from the last couple of decades is pretty much a computer anyway. You can likely get away with a Raspberry Pi to process the data coming from an RTL-SDR dongle, so another $5, and yes, you'll need a monitor, keyboard, and a power supply. The point I'm making is that these two methods are not the same and in the evolving world of amateur radio, there's space for both. It also means that once you have this infrastructure, you can start experimenting with new radio technologies and approaches. Will it make my 857d and its siblings obsolete? Perhaps, but I doubt it. There's still plenty of valve radios going around, not to mention the spark gap transmitter at Grimeton in Sweden. In other words, this is growing the hobby, which ultimately is

Foundations of Amateur Radio While spending some quality time discovering what I don't know about GNU Radio, I explored the notion of attempting to at least understand a little more about how an FM signal works. Depending on your background, the letters FM mean different things. In amateur radio it's a way to encode information, generally audio, using something called frequency modulation. Outside the hobby, the letters point at commercial broadcast radio. While the two are related, they're not the same thing. In amateur radio use, FM is a single channel of mono-audio, however, in commercial broadcast radio, there's a whole lot more going on, interesting because it gives you ready-made access to a composite signal that's just complicated enough to be challenging without being so complex that you need to spend hours on understanding the thing. In essence, a commercial FM broadcast signal is multiple channels encoded in a specific and documented way. This is helpful, since you can compare the documentation against ready made examples and replicate the process for yourself. In case you're new here, I'm in the process of building a radio system, in software, using GNU Radio in a project called Bald Yak. Specifically, the Bald Yak project aims to create a modular, bidirectional and distributed signal processing and control system that leverages GNU Radio. It's called Bald Yak because by the time I'm done, the Yak is likely well and truly shaved. One of the easy things to forget when you're using GNU Radio Companion, is that the blocks you're connecting together on the screen into a flowgraph actually represent software, generated when you either build or run the flowgraph. This code is currently generated in either Python or C++, making me wonder, what does the code look like, and more specifically, what code would be needed to decode FM? It turns out that an old friend, the PySDR.org website has a whole chapter dedicated to this process. Chapter 18, the End-to-End Example, details how you can decode one of the channels embedded within a commercial FM broadcast, the RDS or Radio Data System signal. If you're not familiar, the PySDR.org website represents a whole book about software defined radio and python. It goes into as much or as little detail as you want, to explain how this whole software malarkey works, and takes you by the hand down the path of discovery. So, armed with a working example, I followed along the bouncing ball and made a working RDS decoder and I think, understood most of it. There's a few interesting wrinkles that I've contacted the author, Dr. Marc Lichtman, about and we'll see what comes of that. Here's the kicker. The author, who is also a senior member of the GNU Radio team, started with a GNU Radio flowgraph and reverse engineered what was happening to get to the point of the code that's available in PySDR.org Chapter 18. This is significant because it creates a relationship between the code I have in front of me and the code generated by GNU Radio, which means that when I start with a new flowgraph, not only do I know the steps required, I also know that the outcome is predetermined, as-in, I already know that there's a solution. Having professionally written software for over 40 years, I can tell you that this is not often the case. I realise that I can search the Internet for an RDS decoder flowgraph, but that's unlikely to get me to a better understanding of what GNU Radio is doing. Once I've clarified with the author, I'll add the code to my GitHub project, "Fifty Things you can do with a Software Defined Radio", specifically, "Receive road traffic information", since among other things, that's carried by RDS. As an aside, Rohde and Schwarz have a lovely YouTube video on the topic, "Understanding the Radio Data System", which is giving me a whole set of ideas about things we might attempt with amateur radio repeaters, but that's a story for another time. Meanwhile, have you considered what other signals exist on the RF spectrum that you might want to decode and how you'd go about this? I'm Onno VK6FLAB

Foundations of Amateur Radio How do you make a hole? That's a pretty straightforward kind of question, and by the time this sentence is finished, there's going to be at least as many answers as people who considered it. I didn't supply any parameters to this hole, so answers could include shovels, collapsing space, fire, a drill, or any number of other interesting approaches. If I narrowed it down to, say, a hole in wood, there'd still be plenty of options. Specifying the type of wood, the diameter and other parameters would further narrow down the selection of methods. What if I asked you: "How do you decode FM?" You might wonder if there's more than one way and I can assure you, just like with making a hole, there's plenty of ways to go about achieving this, even if I limit this to software implementations only. I must confess, when I recently set out to test my Soapy SDR library notions using a GNU Radio flowgraph to listen to FM radio, I searched the documentation, found a beginners tutorial and used the information there to make my first proof of concept FM receiver. I put it on GitHub and went about my business. After finally managing to hear the decode effort and being less than impressed, I started trying to understand the tutorial flowgraph. When I started looking at what would be needed to decode stereo FM broadcast radio, I discovered that there were several tutorials, examples and videos with slightly, or significantly different solutions to the problem. That's on top of the over a dozen standard FM related blocks supplied within GNU Radio. I then set about trying to discover the canonical implementation of an FM receiver and came up short. Instead I discovered even more implementations of FM receivers, each subtly different. You should know that there's a difference between how your local hit radio station does FM and how an amateur radio repeater does FM, let alone the local CB radio channels, satellite telemetry, wireless microphones or even hearing aids, so within the implementation of an FM receiver, there's additional complexity, which explains to some extent the variety of FM related blocks within GNU Radio. I think ultimately it's safe to say that there's an unlimited supply of implementations of an FM receiver within GNU Radio. It led me to ask, what is the .. for want of a better word .. "right" way and what does that actually mean? In GNU Radio, you string together blocks that process a signal. If you're familiar with flowcharts, the process is very similar. Unlike flowcharts on a piece of paper, in GNU Radio, or should I say, GNU Radio Companion, the tool you use to actually design flowgraphs, the little blocks represent underlying software and their connections represent how data flows between these bits of software. In other words, each block represents a series of programming instructions that process data and pass it on. It means that the more blocks you have in your flowgraph, the more instructions are running to process data. The more instructions, the more computing resources required. This is significant because in a complex system like this, we're likely to be doing more than one thing at a time, so preserving resources is important, if only to ensure that there's time available to process the next sample. As a result, there's a difference between implementing an FM receiver with two blocks, or with ten blocks. You might conclude that two blocks is more efficient, but that might not be true. For example, two blocks processing 2,000 samples per second each, are processing 4,000 samples per second in total. A block that converts the 2,000 samples into 200 samples, followed by nine blocks processing 200 samples per second each, is processing 3,800 samples in total. All things being equal, the ten blocks together are handling less data per second, so overall it's potentially using less resources. I say potentially, because it might be that one of those blocks is using a massive calculation, consuming more resources than all the other blocks put together, ultimately, each block is software, so whatever it's doing is using resources. So. How would you go about choosing between two implementations or algorithms, which was the "better" one and how is "better" defined? My first pass at this, is to use standard testing files and using the algorithms under consideration to process them. Run the tests multiple times, keep a record of how long they take and then attempt to measure how much the original input signal differs from the processed output signal. At the moment I have no idea how you might compare signals, other than to invert one and combine them to see if they cancel each other out, which means they're the same, or not, which means that they're different. For my sins, in trying to think of a way to do this I realised that the way I implement this radio contraption needs to be able to deal with test files and potentially multiple different implementations of a decoder. It also

Foundations of Amateur Radio Still excited from my minor victory in discovering a missing puzzle piece associated with the project I'm working on, I spent the past week introducing my head, if not literally, at least figuratively, to the surface of my desk in a traditional head-desk troubleshooting move that you might be familiar with. I suppose it's an improvement on the "Bear with a Toothache" approach. In short, the Yak is losing hair .. rapidly. You might be wondering why I'm telling you about it, since in the land of milk and honey nothing ever goes wrong and all the answers are presented on a silver platter, except when they're not. Within the amateur radio community, it appears to me that the inclination to fiddle is ingrained and widespread. Given that the hobby is all about experimentation and learning, that's not a bad thing, but there are times when this behaviour can be counterproductive. Specifically when you're troubleshooting. Faced with a problem, there are times when a systematic approach is warranted. For some, the first time they come across this phenomenon is during the practical test component of their amateur radio license. Presented with a station, they're asked to determine why it's not working. The problem might be a power supply that isn't plugged in, or a disconnected antenna, the mode button set to FM, the squelch closed, the RF gain set to zero, generally something simple. Those inexperienced in the art of troubleshooting are more likely than not inclined to try everything, sometimes all at once, in the hope that one of the changes will magically fix the issue, but in reality, often making the problem worse. There is a better way. I'm mentioning this because this skill applies to many aspects of life and in the decades that I've been here, it's not something I was ever taught. It's funny to think that a quote from nearly a century ago applies to this skill: "When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth." The salient point being "eliminating all which is impossible". In other words, you're not finding the problem, you're eliminating all the things that are not the problem. Another way is to think of it as finding all the things that don't need fixing. While that might sound weird, in deeply interdependent systems like an amateur radio station, or a computer, that approach can help you find the root cause of an issue and with it the path to a potential fix. Of course, this process invites you to examine where the issue might exist. Experience will teach you that you need to start small and grow the net, rather than cast wide and narrow it down. That's not to say that you need to stop paying attention to the bigger picture. In the example of an inoperative station, you might discover that the lights in the room are out and that this coincides with the radio being off. In other words, trying to discover if the antenna is disconnected makes little sense, since there is no power to the radio. In my case, I'm balancing my efforts between maintaining an existing system whilst attempting to deploy a new one to replace it. I'm working on several related issues on multiple fronts. Their common theme is audio, though the specifics differ depending on which computer I'm looking at. Then there's the installation and ongoing care and maintenance associated with keeping GNU Radio running. It's a balancing act because while this is happening, I still need to look for work, respond to email, deal with the regulatory requirements for accounting and tax returns, not to mention the myriad projects I have going on at any given time. At this point I could go into deep and disturbing detail about the technology issues I'm juggling and I could even justify it by pointing out that a problem shared is a problem halved, but truth be told, I'm not sure you're up for a treatise on the comings and goings of forced system security updates and arising bugs, and just so we're clear, this is not the company who brought us a talking paperclip, it's the one who gave rise to companies called "Orange" and "Lemon". On the GNU Radio front, there's a snake based installer that happily installs two incompatible libraries for the same application, causing it to fail, and a beer related one that fails to install dependencies. At least I can use 'apt-get' on a real system. That said, juggling problems and all, I did manage to actually hear an FM station being decoded across the network. It did help that I actually connected the antenna to the radio, and I'm ignoring the audio buffer under-runs, or over-runs, depending on the weather, or some other unknowable variable, but I suspect that's all part of the learning I'm in the middle of. Hopefully, the hair will grow back soon. I'm Onno VK6FLAB

Foundations of Amateur Radio A little while ago I discussed a lovely article by programmer, artist, and game designer "blinry" called "Fifty Things you can do with a Software Defined Radio". This week it occurred to me that I could use their article as a framework to further explore my Bald Yak project. If you're unfamiliar, the Bald Yak project aims to create a modular, bidirectional and distributed signal processing and control system that leverages GNU Radio. For that to happen, I need a solid understanding of GNU Radio and its ecosystem. While I've been playing with it off and on for a decade or so, I have yet to build anything substantial for the simple reason that there was a puzzle piece missing. Last week I discovered it .. by accident. One of the fundamental things I'm attempting to achieve is the creation of a system that doesn't care which radio device you're using. In case you're wondering, I'm doing this because there is a proliferation of device specific software that cannot keep up with the influx of new hardware, doesn't consider the growing use of network connected radios, forced by increased RF noise levels in many communities across the world, not to mention, connecting increasingly expensive computing hardware to lightning rods. If everything goes to plan, it should be possible to use the project with any radio device. This is easier said than done. In GNU Radio this complex issue is addressed by having different blocks that represent different devices. You'll find receiver specific source blocks and equivalent sink blocks representing transmitters. While that's all fine and usable, it means that if I were to publish, say an FM receiver flowgraph, essentially a collection of blocks representing software that implements an FM receiver, I have to decide how I want to deal with the specific device. Do I select an RTL-SDR dongle as the device in my flowgraph and let you figure out how to make it work on the HackRF or the PlutoSDR sitting in your shack, or do I make it completely hardware agnostic, requiring you to wire it all together for your specific situation? Neither is desirable, or simple. Added to this is the problem that trying to make this work using a traditional analogue radio would cause more issues, since there isn't a Yaesu FT-857d block, nor is there one for an Icom IC-7400, let alone something from last century. Someone with some GNU Radio experience might point out that there are source and sink blocks for an audio device, which would allow you to plug one of those radios into a sound card and access the receiver, or transmitter, that way. While that would work, it requires that the radio is physically connected to a computer that's running GNU Radio. It would also give you all manner of headaches attempting to change frequency in the same way as you could using an RTL-SDR dongle. There are several ways to get remote radio control working across a network. For example, using 'rigctld' and 'Hamlib', we can change frequency on over 300 analogue radios, but even if you do, you'll discover that getting the audio across the network creates a whole range of new issues, not to mention that GNU Radio doesn't talk to Hamlib compatible radios. This is why many remote radio solutions are implemented as remote desktop sessions to a computer that is physically connected to the radio. While attempting to solve a completely unrelated challenge last week, I came across 'SoapySDR', described as a vendor and platform neutral SDR support library. Essentially it's a project that allows an application to interact with different devices without needing to support individual radios. This allows an application developer to write their software to support SoapySDR and from then on benefit from its ability to talk to lots of radios in a variety of different ways. For example, one of the in-built features is called 'SoapyRemote' which allows you to connect to a SoapySDR radio and interact with it across a network. Specifically, you can send and receive, as well as control the radio, essentially bundling together both the audio and control signals. SoapySDR also includes a tool called 'soapy-audio'. While documentation is sparse, it appears to support Hamlib, which means that you can, at least theoretically, connect a low powered computer, like for example a $5 Raspberry Pi Zero, to your analogue radio and access and control it across the network. Best part? It's supported by GNU Radio and many other applications. I've started creating a repository with the "Fifty Things you can do with a Software Defined Radio", one directory per thing, that will contain the bits needed to run inside GNU Radio and across the network to any SoapySDR compatible hardware. Now, before you get as excited as I am, there's a few hurdles. I'm not yet sure of the status of soapy-audio, but it looks promising. I have the bits sitting on my computer and I'm working through them. For example, I'm not sure if the current implement

Foundations of Amateur Radio How to go about documenting your setup? Possibly the single most important thing that separates science from "fiddling around" is documentation. Figuring out how to document things is often non-trivial and me telling you that "unless you wrote it down, it didn't happen" only goes so far. If documentation isn't your thing, what about "I broke something and I don't know how it was before I fiddled" as an incentive instead? Recently I had cause to explore how to document how my station is configured. To give you a sense, the microphone is connected to a remote-rig, which is connected to a Wi-Fi base station, over Wi-Fi to a Wi-Fi slave, to another remote-rig, to the radio body, to the VHF port, through two coax switches, a run of RG213, to an antenna. When receiving, it goes from the antenna, to a run of RG213, through two coax switches, to the VHF port, to the radio body, to a remote-rig, to a Wi-Fi slave, to a Wi-Fi base station to a remote-rig, to the remote head, to a set of headphones. Of course, at this point I've written it down, so, job done .. right? Well, what about the data connection, the external speaker, the remote head display and other goodies, say nothing of the duplicate devices with similar names. All in all, the FT-857d has something like eleven ports, each remote-rig has ten, so just wording it is a start, but hardly qualifies as documented. What if we drew a picture instead? At this point you could pull out your crayons and start scribbling on a sheet of butcher's paper and that would be a fine start, but it would be difficult to share with me or anyone else and updating it would be a challenge, let alone versioning it. As it happens, we're not the first people to have this issue. In the 1980's and 1990's researchers at Bell Labs were trying to figure out how to draw graphs and from that work a language, 'DOT', since everyone is a fan of the "DAG Of Tomorrow", and a series of tools, which today are known as 'Graphviz', made the visualisation of relationships possible without the application of coloured wax on dried cellulose fibre. In my other, computing job, I had cause to visualise the relationship between a million or so nodes, allowing me to discover a specific node that was directing all traffic, where I could insert my debugging code, but it was only possible thanks to these free and open source tools. While the DOT language isn't particularly complex, it occurred to me that for someone not conversant with the syntax, we can start even simpler with a CSV text file that shows the relationships between each device and convert the CSV to DOT and in turn to a picture. For example, I documented the relationship between the radio and the antenna by adding five lines to a CSV file, essentially, FT857d to VHF port to VHF coax switch to VHF grounding switch to RG213 to antenna. In all, to document everything except power, since I haven't decided how I want to describe it, I used a CSV with 47 lines. On the face of it, that might sound ridiculous, but I can tell you, it shows all the sockets on the FT857d, all the sockets on both remote-rig devices and the relationships between them. With it anyone can duplicate my set-up. Having previously spent some quality time learning various aspects of the DOT language, I figured I could write a little script to convert CSV files to DOT, but being of the generation of software developers with the attitude, "Why write something if someone else already did?", I discovered that Reinier Post at the Eindhoven University of Technology has a delightful collection of scripts, including one appropriately named 'csv2dot'. Written in Perl, the only language that according to some looks just as impenetrable before and after encryption, the tool works as advertised and makes a DOT file that you can then visualise using Graphviz. Of course there's Python scripts lying around that claim to do the same, but I wasn't keen to install the kitchen sink just to try them. Instead I made a quick little Docker file that you can find on my vk6flab GitHub repository that will walk you through this, complete with my example, so you have a starting point. Now, I used this here to describe my station, well, one part of it, but it can easily extend to document your entire station, and because we're talking about text files that contain the information, anyone with a copy of a text editor can update the file when things change, since that's where the real magic happens. So, what are you waiting for, documentation? I'm Onno VK6FLAB

Foundations of Amateur Radio Just under a year ago I started an experiment. I set-up a beacon for WSPR, or Weak Signal Propagation Reporter, transmitting at 200 mW into a dummy load using eight bands between 80m and 10m. I also set-up an RTL-SDR dongle, connected to an external 20m HF antenna and made it monitor 18 amateur bands between 630m and 23cm. I left this running 24/7 for most of the year, though there were times when I detached the antenna due to local thunderstorms and there was a seven week period where there were no reports. It's highly likely that I forgot to reconnect the antenna, but I don't recall. For this analysis I used the online WSPRnet.org database where I uploaded my spots as they were decoded. I noticed that there are reports that I have locally that are not in the database, though I'm not sure why. They're incomplete and not in the same format and merging these is non-trivial for reasons I'll discuss. Lesson learnt, the "rtlsdr-wsprd" tool needs to be patched to output the data in the same format as is available from the online database and I need to actively log locally. The results are puzzling, at least to me right now. Let's start with the low hanging fruit. There are no reports of my WSPR beacon being received by anyone other than me. That doesn't guarantee that nobody heard me, just that nobody reported that they did. In the database there's just over six thousand reports of my station receiving a WSPR transmission from my beacon during the past year. The reports cover all bands, though not equally. The 80m band represents 6 percent of reports, where 40m accounts for 20 percent. The reported SNR, or Signal To Noise ratio, varies significantly across the data. For example, the 12m band shows a range of 42 dB. Digging into this does not reveal any patterns related to date, time of day, season, other band reports or any other metric I was able to imagine. In my exploration, missing records and time-zone differences aside, I discovered that the local data does not appear to match the database. For example I have records where the software decoded my beacon ten times in the same time-slot, but none of them exist in the database. For others, there's only one matching record, which leads me to believe that the WSPRnet.org database only accepts the first report for any given combination of timestamp, transmitter and receiver, but I have yet to confirm that. So, let's talk about getting more than one result for a specific time-slot. As you might know, a WSPR signal is transmitted every 120 seconds, starting at the even minute. Each transmission lasts 110.6 seconds. The decoder will make several attempts to decode multiple, potentially overlapping signals. It is my understanding that the way this happens is by essentially removing a known decoded signal and then attempting to decode what's left, repeating until either there's no more signals to decode, or time runs out, since there's probably only really 9.4 seconds in which to do this. Potentially this means that a faster computer will decode more signals, but I've not actually tested that, but it's probably something worth pursuing. Back to our decodes. If the first decode is removed from the received data and the next decode gives you similar information, same callsign and maidenhead locator, with SNR and frequency differences, then you might imagine that there's so much of it there that the only way that might happen is because the receiver is overloaded. I'm still looking into this, because if that's the case, then we'd need to determine if the receiver was always overloaded, or only sometimes. It's curious, since there's over a thousand other signals being received from other stations, several over 18,000 km away, so it's not like the receiver is completely swamped. Another hypothesis is that the decode is coming from a different band, like a harmonic. This is potentially caused because from a band and timing perspective, the receiver isn't linked to the transmitter in any way. The transmitter hammers away 24/7 one band after the next, switching every two minutes, the receiver listens for half an hour on a band, then randomly picks the next, until it runs out of bands and starts again. The receiver is listening on more than twice as many bands as the transmitter operates on, but that doesn't mean that it cannot hear the transmitter on a harmonic of one of the bands. Again, I don't know if this is the case, or if something else is happening. One thing I'd expect, is to see reports on other harmonics outside the bands that the transmitter is using, but I'm not seeing that. Perhaps the overload is limited to just the band we're actively monitoring and the other signals are coming in regardless of the overload. I'm still trying to determine if that's the case. As I said, merging the data from the two sources is non-trivial, time-zones and formatting are not the same and I'm not in the mood for manually fixing 2,500 or so records, not

Foundations of Amateur Radio The other day a fellow amateur revealed that they qualified for membership of the QWCA, the Quarter Century Wireless Association .. twice over .. there may have been some innocent whistling involved. During the ensuing discussion it emerged that it all started with a crystal radio set built together with dad, which triggered a whole lot of memories and made me consider just how you'd get into the hobby of amateur radio today. I think it's important to notice that amateur radio is a hobby. There are public service and emergency communication aspects to the experience, but it's essentially a hobby. It's supposed to be fun. I'm mentioning this because that might get obfuscated when I tell you that in order to actually be a radio amateur, you need a license. This license is required because when you transmit, radio waves don't know about international borders, don't know about interference, don't know about priorities and other aspects of our deeply interconnected world. Think of it as a way to formalise your responsibilities. Note that I said "when you transmit". You don't need an amateur radio license to listen, which you can do right now using all manner of online tools in your web browser, "WebSDR", "KiwiSDR" and "shortwave listener" are useful search terms if you're inclined. Getting an amateur license is not difficult. There are many amateurs who were licensed as a teenager, or even younger. It sets you up for life and amateur radio license in hand, you can start transmitting on dedicated amateur frequencies or so-called "bands". A license is required in every country and how that specifically happens in your country will require that you do a little research. Most countries have a so-called "peak body", an association that represents amateur radio to their government, it's a good place to start. In Australia where I live, it's called the Wireless Institute of Australia or WIA. In the United States, it's the ARRL, the UK it's called the RSGB. Searching for "amateur radio peak body" and your country should get you there. If you're stumped, your national telecommunications regulator is often another good place to find information, ultimately you'll be obtaining your amateur license from them anyway, even if they don't actually run courses and exams, though some do. Essentially what you're looking for is, where you need to go to get an amateur license and what's involved. As far as I know, most of this infrastructure is run by volunteers, fellow radio amateurs, even if there's a fee involved. You should also know that amateur licenses generally come in different flavours or levels. For example, in Australia there's currently three levels of license, Foundation, Standard and Advanced. The USA has Technician, General and Extra. The UK has Foundation, Intermediate and Full. The Netherlands has Novice and Full. In other words, what it's called and how many levels there are is country dependent, as are their requirements. I'll also mention that whatever license level you pursue, it's your hobby. You get to decide if, how and when you look for more responsibilities with a higher level of license. It might surprise you to know that I hold the basic Foundation license in Australia. I've held it since 2010. So-far I've yet to have a need to pursue anything further, despite regular "encouragement" to "upgrade" to a "real" license. You do you. It's your hobby. Some countries allow all of this to happen online, others require that you use pen and ink in person in a dedicated classroom, and everything in between. If you are hard of hearing, blind, or unable to physically attend, there are often specific tools and processes available to help you, make sure you ask. As an aside, I will mention that, as in life, there are people in this community who are less than welcoming and will go out of their way to be obnoxious, obstructionist or worse. Fortunately, while vocal and destructive, they are in the minority. Don't let their behaviour dissuade you from participating. You'll find amateurs all over the planet who will welcome you into the community with open arms. There are thousands of local amateur clubs, online resources and of course potentially a couple of million radio amateurs at the other end of your antenna. It's important to understand that the journey into amateur radio is different for everyone. For many long term amateurs the experience came from a family member or neighbour. While that route still exists, it's much less common as an introduction as it used to be. I first came across it as a teenager during a sea scouting event called JOTA or Jamboree On The Air. Whilst memorable, it wasn't until two more amateur radio interactions, decades apart, that I finally got to the point of actually discovering the hobby. For your journey, just being here, today, right now, is already a start. Welcome, it's nice to have you here. You've found the community! What are you waiting for? I'm Onno

Foundations of Amateur Radio Building a shack makes a number of assumptions about your situation and to make it abundantly clear, it's not the only way to enjoy the hobby of amateur radio. Visiting clubs locally and remotely, being a member of a club, visiting other amateurs, setting up your station in a suitcase or a backpack, on a bicycle, in a car, on a bus, or in a boat are some of the many other avenues open to you. That said, there is something magical about building your own shack. It has the ability to transform your hobby and if you have the opportunity, I can highly recommend it and I'd like to encourage you to consider the notion. As I've said previously, there is plenty of exploration and learning associated with putting one together. After you've spent some time reflecting, planning, designing, sourcing, building and testing the environment where you do amateur radio, you're likely to reach a point where you'll refer to that space as "your shack". You might even come to think of it as your shack, rather than a collection of trade offs that you've constructed in the best way you know how. Inevitably, you'll wonder what to do next. Several things come to mind. Creature comforts is probably the most obvious, a push to talk foot pedal, or a desk microphone, either on a stand or hanging from a boom, an audio mixer, a couch, a soldering station, a microwave oven, a fan, or air conditioning, in other words, plenty of opportunities for improvement and enhancement. Then there's computing, something that might interest you, or not. It offers the ability to explore a whole different side of amateur radio, from logging through to digital modes, from weak signal propagation to tracking satellites, the possibilities are endless. Your shack is also potentially a communal place where you can meet with your friends to share the experience. It's a place for contemplation, for relaxation, for "being" an amateur. All of it is open to you as possibility, an excuse to improve and enhance. The thing is, that too will come to a point of, let's call it "completion", and you're left with more questions. Amateur radio is inherently experimental in nature, that's the whole point of the pursuit. Your licence gave you access to the playground, your shack is that playground. Now it's up to you to play. Of course what playing looks like is unique to you. Over the past 15 years I've been describing what playing looks like to me, and from the over 3 million downloads last year from my website alone, not to mention the newsletters, rebroadcasts, podcast inclusions, other streaming services, news reports, social media and messages I've received, they've encouraged you to explore and investigate this wondrous activity. The point is, the shack you just completed isn't finished and hopefully it never will be. Whichever one it is, the first one, the one after that or the next one, your shack is a place where you can experiment, learn, discover, test, fail, succeed, challenge and enjoy the hobby of amateur radio. It's not the only place where you'll find this hobby, but it's your place. So, have at it. I'm Onno VK6FLAB

Foundations of Amateur Radio On your amateur radio journey, you'll likely discover that many transceivers run on 13.8 volt DC, give or take. For example my FT-857d requires 13.8 volt plus or minus 15 percent, with a negative ground, and a current draw of 22 ampere, more on that later. In other words, the power supply needs to be between about 11.7 and 15.9 volts, the same voltage that runs most vehicles with some wiggle room for fluctuating alternator charging cycles. While some radios will absolutely fit in your car, there's plenty where that just isn't the case, even though they're set-up for a 13.8 volt power supply. You might think of it as an anachronism, a few steps removed from spark gap transmitters, but there's more to the story. Most residential power grids run on AC power, at varying voltages and frequencies between 50 and 60 Hz. Across the world there's eight different AC voltages in use between 100 and 240 volts. Some countries use more than one combination and I haven't even looked at three phase power. Perhaps 13.8 volt DC isn't looking quite as odd. With this revelation comes the need to actually have 13.8 volt available in your shack. Converting your grid power to something you can plug your gear into requires some form of transformation, typically achieved with a power supply. Efficient, cheap and plentiful, the switch mode power supply is the most common. Built to a price, they're also often noisy, not just the fan, but noisy from a radio emissions perspective. Amateur radio has very sensitive receivers and as a result you can often hear, or see if you have a waterfall display, RF birdies, a sound reminiscent of a budgie whistling, every 100 kHz or so across the whole radio spectrum. Not something most other equipment cares about, so you're often left to fend for yourself in figuring out how to deal with this phenomenon. There's plenty of filtering techniques and circuits to be found and some of them even work, but for my money, I'd spend it on a power supply that doesn't make noise in the first place. A regulated power supply maintains a constant output voltage or current, regardless of variations in load or input voltage. An unregulated power supply can wander all over the place. Adjustable power supplies allow you to set the voltage, amperage, or both, sometimes with knobs, sometimes using external controls. At this point you might decide that this is all too hard and you want to do away with all this complexity and use a Sealed Lead Acid, or SLA battery, after all, that's what the 13.8 volt is based on, but then you'll need to charge it. Similarly, picking any battery technology requires some form of charging. Another word for charger is: power supply, often a switch mode one, and likely not filtered in any way that matters to you, since batteries, and for that matter solar power inverters, are unlikely to care about RF birdies. I will make mention of linear power supplies. When I started on this journey, this was the strong recommendation from my peers as the most desirable option. Although they're significantly less efficient than switch mode power supplies, only 30 percent versus better than 80 percent, from an RF perspective, they're extremely quiet. Of course, the lack of efficiency reveals itself in the form of heat, which necessitates the application of cooling, from a fan, often a very noisy fan. One potential source of power supply is a computer power supply unit or PSU. Before you go down that route, consider that they're intended for installation inside a case, often generate various voltages at very specific current draws and are not typically known for being RF quiet. After weighing up all the variables, I chose a laboratory grade switch mode current limiting adjustable power supply. It's set to 13.8 volt and it sits on my desk doing its thing. Rated at 1 to 15 volts at 40 ampere, it's now as old as I am in amateur radio terms, well and truly a teenager, it's also overkill, by quite a margin. Remember when I mentioned that my FT-857d is rated at drawing 22 ampere? As a QRP or low power station I typically use my transmitter set to 5 watt, but even when others use it at full power, I have never ever seen it draw more than 12 ampere. That's not to say that it can't draw 22, I've just never seen it. As a benefit of having such a massive overkill in the specifications of my power supply, I can power more than one radio and not notice. Not that they're all transmitting at the same time, or using more than 5 watt, it just doesn't matter. I previously discussed setting a standard for coax connectors in the shack, the same is true for deciding what to pick for power supply connectors. In my case I chose Anderson Powerpole connectors. Pins come in 15, 30 and 45 ampere ratings, are genderless and housings are available in many different colours. When I say genderless, it means that you can join two identical connectors. Within my shack, I use the RACES or ARES Powerpole wiring stan

Foundations of Amateur Radio Noise la la la la la hinders if I were a rich man effective a noise annoys an oyster communication but a noisy noise annoys an oyster more. Or said differently, when you're trying to communicate, something that the hobby of amateur radio does in spades, you'll need to deal with a phenomenon called noise. This noise comes in different forms, but the effect is the erection of barriers to successful communication. We refer to the impact of noise as a signal to noise ratio or SNR, the signal being the desired information, the noise the undesired interference. Expressed in decibels so you can deal with a massive range using a small number, an SNR greater than 0 dB means that the signal is stronger than the noise. Building a shack requires that you consider noise in many forms. If you've been a radio amateur for a few moments, your mind is likely to head straight for the hiss, crackle and pop you might hear whilst attempting to communicate on HF, but there's a few other things to discuss. There's all sorts of electronic noise received by your radio. In addition, there's audio noise picked up by your ears, and often your microphone. Then there's the noise that you produce, either from your transmitter into the rest of the building, or from your mouth or speakers into the ears of the people you share the space with. Starting with audio, having a space that you can close the door on is a good way to limit the noise coming into and leaving your shack. An alternative is to wear headphones and generate text to speech, or prerecord your voice, ready for a contact, potentially ideal for contesting, not so much for free form discussion. Another consideration is audio from other radios, including those tuned to a local broadcaster, or aviation frequencies. In other words, if you're transmitting with a microphone, make sure that there's no other audio coming through. In some cases it's even illegal to transmit that audio, but in all cases it's noise that makes communication more difficult. This kind of audio noise mitigation is pretty straightforward. In stark contrast, achieving the same with electronic noise is pretty much a balancing act between budget and effectiveness. The impact of noise is inversely proportional to distance. Essentially, the closer it is, the more impact it has. With that in mind, when you start dealing with noise, start nearby and work your way out. As you eliminate the nearby noise, other sources will become apparent. Without turning this into a noise mitigation class, the process is essentially one of elimination. First locate the noise source, then eliminate it. That's easier said than done. For example, if the noise source is a power supply sitting on your bench, you can turn it off, except if that power supply is the one powering your radio, so perhaps I should say: "attempt to eliminate it" instead. There's plenty of ways to have a go at this and volumetric kilotons of content published on the subject, some of it even useful. In many, but not all cases, noise is an electrical phenomenon that enters via any means possible and you'll need to attempt noise mitigation at multiple points of entry. Obvious sources are the power supply, coax and the antenna connection, the speaker cable, the microphone lead, and if you're using a computer, the USB, serial or Ethernet cable and within the computer itself. Each requiring different approaches. The obvious one is to disable the noise, that is, turn off the offending device. As I said, that might not be an option, but you can replace noisy gear, or place it further away. There's isolation, using tools like ferrites and chokes to stop the noise from reaching your radio. Often in the form of a clip-on blob, you'll find these on things like monitor and USB cables. Place the ferrite as close as possible to the input of your radio. If it's loose on the cable, wind it through the ferrite, the tighter the better. There's software solutions with varying levels of effectiveness. You'll find DSP or Digital Signal Processing knobs and buttons on many radios. They're generally helpful for narrowband repeating noises, like the hum of an electric motor or power supply. There's tools that attempt to impose a noise on your signal that cancels out the noise, anti-noise, if you like, by receiving the noise, inverting it and adding it to your signal, thus, at least theoretically, eliminating it, noise minus noise is silence. This can take the form of a device for noise coming in from the antenna, but it also applies to things like noise cancelling speakers. In audio this is called active noise cancelling. There's also a new crop of noise cancelling software, using A.I. or Assumed Intelligence, that captures your signal, attempts to figure out what's noise and what's not, removes the noise and then feeds it back to you. Your Mileage May Vary and if you break it, you get to keep both parts. Consider your privacy and security implications of sendin

Foundations of Amateur Radio Putting your station together is best described as a juggling act, since you'll discover that everything depends on everything else and the more you plan, the more you learn and the more variables become apparent, none more so than with the selection of an antenna. Antennas are endlessly variable. To give you a taste, imagine a loop of wire, shaped like a circle. As you stretch the circle, it becomes an oval, if you pull on four corners, it's a square, pull it tight between two points and it more or less becomes a single wire. In other words, one piece of wire can essentially make an infinite number of antennas, and we haven't even varied the material, length, thickness or coating. So, to discuss antennas is to embark on a lifelong journey of exploration and me telling you to get one over another is not going to help, instead I'd like to discuss some considerations that you might not have encountered. The obvious issue of space is generally the first consideration. Then there's the neighbours and their sense of aesthetics, or lack thereof. There's local laws to abide by and sometimes permissions and permit requirements, though in many cases it seems that seeking forgiveness is a quicker route to success. Your Mileage May Vary. Talk to your local amateur club. There's the property owner to consider. If that's you, great, drill away, if not, you will need to tailor your antenna selection to the amount of renovations required. If you live in a restricted location where there are all manner of rules about the things that you cannot do, you might need to think carefully about your options. Stealthy antennas are a thing. As I've said previously, inside your roof might be an option, but there are others. Some examples to consider. If there's a TV aerial on your roof, will that look similar to a 70cm Yagi, or could it hide a 2m vertical? Do you have a metal gutter which might act as an antenna, or could you use Christmas light clips to hang a wire antenna from your gutters? Could you hide a vertical in a plastic down-pipe? Could you dangle a ladder-line antenna out a window at night, or use thin wire to hold up your plants while hiding your antenna in the garden, or can you use a beverage antenna that's lying on the ground, or hidden under the fence capping? Could you tune up your fence for that matter? In other ways to make your hobby look invisible in plain sight, could you use an antenna that looks like a roof vent, or if you're into moon bounce, could you repurpose a satellite dish? Could you make your outdoor washing line into an antenna or add a flagpole vertical antenna that also happens to soothe your vexillology sensibilities? While we're talking stealth, you can paint your antenna to match the decor. To get your antenna up in the air, could you use a length of wood, a pool cleaning or painters pole, strapped to your pergola, gazebo, balcony railing, or some other existing structure? Can you use the edging of a shade sail, professionally installed, it comes complete with mounting points. It doesn't stop there, I've heard of several amateurs who managed to park a sailboat, with the mast up, in their driveway without ever once floating it in a nearby body of water. Of course this is not exhaustive, nor is it meant to be, it's really a trigger to think about some options you might not have discovered. In other words, if you need stealth, you can be creative, rather than buy an antenna off the shelf. Speaking of buying off the shelf, there's nothing quite like buying a wonderful antenna, the answer to all your questions, only to discover that it needs tuning and tweaking, to the point where you might spend a year getting familiar with all its quirks. That's not to discourage you from picking that path, just to warn you that there is no such thing as the perfect antenna. If you are less space restricted, building a tower or a mast, the difference being that a tower stands all by itself, like the one in Paris, a mast needs guy-wires to keep it up. You'll likely need to consider failure, engineering standards and concrete, not to mention maintenance. So, how do you go about selecting the perfect antenna to suit your needs? In the same way that a magician pulls a rabbit from a hat. In other words, there's a trick. It's pretty simple, start small. With that I mean, start with a simple wire antenna. It will achieve a number of things that only experience will give you. For starters, it will prove that your shack works. As-in, end-to-end. That might not sound like a big deal, but there are many different moving parts in building a successful shack, making your first contact is going to be a milestone worth logging, more on that another day. While making your first contact is momentous, getting an antenna in the air will also allow you to hear what your neighbourhood sounds like. Is it completely RF quiet, in which case, where do you live and do you have a spare bedroom? The reality is, fo

Foundations of Amateur Radio When you start the process of getting your hobby off the ground, either for the first time, or after a hiatus, you might be left with the impression that the only way to "do amateur radio" is to have a shack, a place where you can set-up your gear, and connected to that gear using coax, one or more antennas. While that's a common scenario, it's not the only one at your disposal. We are after all in the game of communication and over the past few decades options have exploded. Starting closest to the traditional radio, coax and antenna, is to consider indoor antennas. There's many to choose from. You can install one in the same room as your shack, or, you can build your antennas in the roof space, either way, invisible from the outside can sometimes be a requirement. Stealth is a topic all its own, and no doubt we'll get to that another time. A word of caution. If you do have an indoor antenna and associated coax, consider your transmitter power levels, since it's likely that given the close proximity, you'll exceed emissions safety standards, or you'll cause harm to other electronic equipment in the building. QRP or low power is a good way to go if this is something you're considering. If we step away from a traditional radio, coax, antenna configuration, you can build your shack in other ways too. For example, you can use a local repeater which you might trigger from a local handheld radio. Often dismissed as being for local communications only, there are thousands of repeaters across the globe offering a variety of bands, frequencies and modes. Often you can access a local repeater that can be connected to a remote one using a bewildering array of technologies, some using the internet, some using traditional RF. You'll find repeaters on 10m, 6m, 2m, 70cm and 23cm. There's nothing stopping you making your own repeater. You don't even need to go through the effort of making it completely standalone, for example, my Yaesu FT-857d has a detachable face-plate or head, connected to the main body by a short cable. There are plenty of other radios with a similar configuration. Presumably designed for the installation in a vehicle, where the head needs to be near the driver and there's unlikely to be space for the body, you can run a longer cable from the head to the body and install it somewhere more convenient. In my case it was bolted underneath the removable floor into the boot next to the spare tyre. There's several solutions that replace the connecting cable with an internet connection. Now, that internet connection can be across the room, from inside your shack to your garage, or between your shack and a remote hill where you have permission to put up a bit of gear. In fact, the same type of setup can be used to connect to shared radios, and companies like Elecraft, Flex Radio and ICOM make specific remote heads that can operate remote radio equipment, marketed as RF decks, without needing to install and maintain computers at either end, but more often than not, this equipment is brand or model specific. Which raises another option. You can connect to remote equipment across the internet using your computer, which means that your shack might be a computer, a laptop, or a mobile phone and your gear might be in a different country. Many radio clubs have discovered that their often extensive radio shack is virtually unused during the week, and have installed remote equipment to allow you as a member to connect, sometimes as part of your membership, sometimes with an extra fee, since there are costs associated with setting this up and keeping it running. At some point you're going to discuss this with other amateurs and you're potentially going to hear someone tell you that this is not "real radio". Considering over a century of radio evolution, from spark-gap through valves, transistors, integrated circuits and software defined radio, where exactly is the "real radio" line drawn? Is using WSPR, RTTY, FT8, Hellschreiber, Olivia, SSTV, PSK31, Domino, MFSK and thousands of other digital modes "real radio"? If the answer to that is an emphatic "yes", then ask yourself, how do you actually use those modes? The answer looks suspiciously like a computer running digital mode software, either connected to a physical radio in the same room, or connected to one across the internet. In other words, with the proliferation of communication alternatives, amateur radio is evolving. No doubt it will evolve further. So, today, a perfectly viable, and some might say, modern, amateur radio shack might not actually have any traditional RF based radio gear, though perhaps a hand-held might be something to consider when you next treat yourself, not because without it you're not a real amateur, but because it opens your world to other means of communication, something which I think is perhaps even more important than building the perfect shack. In other words, you are not required to have a shack to be a

Foundations of Amateur Radio One of the potentially trickier aspects of putting together your shack is connecting the radio to the antenna. On the face of it, the challenge is limited to making sure that you have mating connectors on both ends, but when you actually start implementing this you'll run into several other considerations. The very first one as I said is the connector. Every amateur I've ever spoken to goes through the same process. You pick a connector, typically the one that your radio comes with, then you adapt the connector on your coaxial cable to suit, then you'll get an SWR meter, a dummy load, some testing gear, a coax switch or two, perhaps another radio, or an amplifier and along the way you'll discover that you now have a growing collection of connectors to choose from, and that's just the connectors inside the shack. After considering connectors, you'll start to contemplate the coax itself. You'll likely weigh price against signal loss, but there are other aspects to the selection of the right coax for the job. For example, how do you get the coax actually into the shack? One of the main challenges associated with solving that problem is surprisingly something that rarely affects our hobby, other than any human factors associated with the phenomenon of "weather". Getting coax into a shack generally involves passing through a weather proof barrier of some sort. In doing so, you're likely to create a place where the weather can make its way into places it's not supposed to. Water can and will travel along your coax. Hopefully on the outside of it, but if you're unlucky, on the inside too, likely destroying it along the way. At first glance you'll think that water only travels down with gravity and in an ideal world you'd be right, but as it happens, water will happily do other things like get blown by the wind, or condensate in temperature gradients, like those found near a hole you just created in your lovely weather proof barrier. If your shack has existing openings, they're generally the easiest to appropriate, things like gaps in the eves, existing vent holes, between roof tiles or sheet iron, plenty of existing places where you can get from inside to outside a shack. Note that this is also the case if your shack is a trestle table tucked away in an office, like mine. Before I continue, I'm about to raise some potential safety issues, but I'm not an occupational health and safety professional, so, do your own due diligence. If you do need to go into your roof space, height aside, consider it a dangerous place. Make sure that there's someone to check on you and consider alternatives to climbing up there. Wearing a face mask and full body clothing is a very good idea. Often you'll find exposed wires, deteriorating or toxic insulation and other nasty things, conductivity of steel roof frames and pipes are also a hazard, so be extremely reluctant to venture there. Avoidance is preferable. Working at heights 101: Don't .. that said, there may be no alternative. You can lift corrugated iron sheets by undoing the roofing screws. If you do, make absolutely sure that you don't make a string of water inlet points when you put it all back together. In lifting a sheet, you can access the roof space and run your coax. Sometimes the gap between the corrugation and the rafters is sufficient to push the coax through, but if you live in a hot climate, make sure that it doesn't touch the sheeting, since coax is likely to distort, if not outright melt, if it's in direct contact with the iron sheet while the sun is belting down on it. Consider the temperature rating of your coax. Similarly, terracotta roof tiles tend to have enough space to allow coax to enter the roof space. Be very careful, since they're often fragile and potentially irreplaceable. Look for openings like existing roof fittings, things like chimneys, vent pipes, roof ridges, etc. for simpler points of entry. If you need to make a hole in your roof and seal it, there's special rubber grommets for this purpose. You cut a little opening in the grommet, too tight for the coax, then force it through. Seal to the roof with UV-stable silicone and you're good to go. Check them every so many years, they deteriorate. Speaking of silicone, if there's an existing hole that you're using, don't just seal it up, it might be there for a reason. Windows often have vent holes or gaps that will fit some types of coax and there's inserts you can use to open a sliding window that will accommodate coax, but consider the security of that window before you commit. There's also special flat coax for running through a window frame or under a door, but check before you buy that they're suitable for the job. Ladder line is also an option, it's much thinner, can travel longer distances, but its performance can be affected by corrugated iron and other conductors. Rarely if ever does the initial acquisition of coaxial cable involve details like "bending radius", t

Foundations of Amateur Radio When you start on the journey of putting together a shack, in whatever form that eventually takes, you'll need to figure out how much space is required. Of course, no matter what you choose, it's never enough, but you have to start somewhere. Ultimately a shack is a work in progress. As an aside, I'm using the word "shack", but that is really an amateur concept, so we're not necessarily talking about a plot of land with a wooden lean-to cobbled together from bits of wood collected from your beachcomber days. Not that it can't be that, but it doesn't have to be. As I've said, my "shack" is a wooden trestle table, I know shacks that are a dedicated room in a house, a converted garage, a garden shed, a warehouse office, a radio station, an out building, several scout halls, demountables, a converted passenger bus and plenty more. In this context, in referring to "shack", I mean, "the place where my radio lives when I get on-air to make noise", but "shack" runs off the tongue a little easier. Budget aside, in order to attempt to quantify your space requirements, you need to figure out what you're going to do with it. This perhaps sounds a little ludicrous, since the answer is "amateur radio" .. duh .. obviously. Okay, so, here's some questions. Does amateur radio for you mean any of the following: operating the local repeater, HF radio, solo or with visitors, listening to multiple stations, operating multiple bands simultaneously, computers, Morse code, contesting, soldering, building, experimentation and plenty more. While we're at it, if you're into soldering, is that with valves, discrete components, or integrated circuits, and what levels of existing bits and pieces do you have? I'm asking because the racks of jars, component trays and drawers I've seen over the past fifteen years often rival the actual shack for size. In other words, when you're thinking about .. what .. you want to do, be specific. For me, amateur radio is more about computers and less about soldering irons, that's not to say that I don't own a soldering iron, just that its use is incidental, rather than fundamental, computers, keyboards and monitors on the other hand, for me, are part and parcel of my amateur radio experience. Truth be told, if I could, I'd try to eliminate all the analogue radios from my shack and replace them with a single box capable of wide band operation across the amateur bands that I could control with a computer. I realise that this is not a universal picture of what amateur radio means, but it's what it means for me because it represents the ultimate level of flexibility. That said, I love my FT-857d. I have several other radios that I loan out from time-to-time to new amateurs while they find their feet. I love to experiment with those as well, so my shack needs space for temporary set-ups. While I enjoy chewing the fat over a cup of coffee, I rarely get on-air and make noise with anyone else. That's not because I don't appreciate it, but because I've yet to discover an effective way of filtering interference, a topic for another day. Even if you're not a computer nerd like me, there's a high probability that a shack today includes a computer of some description, for record keeping, propagation forecasts, logging, and digital modes. So it's a good idea to imagine yourself actually doing your planned activities and speculating what kinds of things you'll need. Like, where do you put your cup of coffee, your keyboard and your Morse key? While we're discussing putting things down. Think about the ability to actually use these things, not just where they live. It's no fun balancing a keyboard and trying to reach over the top to change the operating frequency, or having to strain your neck to look at the logging screen when you've made that elusive contact, so think about the ergonomics of what you're planning. Right now I have a wire shelving unit sitting on my desk. It's 80 cm tall, 90 cm wide and 30 cm deep. The two shelves are adjustable in height. Currently one is at the highest point, the other has enough space to fit a base-station radio underneath it, about 13 cm from the lowest point. It's not ideal, since it means that the keyboard is in front of it. During the previous iteration, of which there have been several, my monitors were in front of this and the keyboard was an external one connected to a laptop to the right of the screen, allowing me to have two screens to display information. The idea was that I'd use the computer to control the transceivers using a protocol called CAT. This never happened, so operating was awkward to say the least and as a result, hardly used. Instead the FT-857d sat on top of the bottom shelf, using a sound card to operate on digital modes. A slightly better operating angle, were it not for the monitor that hid it from view. As I said, not ideal. I'm mentioning all this to give you a picture of at least one other shack but in my experience, nothin

Foundations of Amateur Radio Recently it occurred to me that I haven't been using HF in my shack for much longer than I'd care to admit. Over the years I've spoken about my shack and how it's set-up, more on that shortly. I effectively went off-air when I decommissioned the computer that was running tools like "fldigi" and "WSJT-X". Mainly because it was too slow, for example, taking a good minute to launch a copy of Firefox. After that I repurposed my HF antenna for use with my ultra low power WSPR beacon experiments and essentially ceased being a functional HF station. There's other forces at work, which I'll get to, but before I do, in discussion with a fellow amateur we discovered that my desire to get back on-air on HF is essentially the same journey that a new amateur might make and the idea was hatched to document the process and share it with you. In the past you've heard me say that the answer to most questions associated with amateur radio is: "it depends". As a new, or returning amateur, this might not be very helpful if you don't know what it depends on, so, I'm going to attempt to describe the process of determining how to get to the answers required to make a station. Now, before I start I'd like to talk about money. I'm raising this upfront because your access to a budget determines many of the choices that are open to you. You could interpret that to mean that you need money and while that helps, it's not universally true, in fact I'd go so far as to say that you could get on-air and make noise using nothing more than a mobile phone and an internet connection, which truth be told is pretty much the minimum requirement to enjoy my thoughts, so perhaps that's the base requirement. That said, even if you don't have access to that, there's other options that we'll no doubt explore together, so keep that in mind. I think that the very first thing to consider is what you think of when you hear the term "amateur radio". I've said it before and I'll say it again. Amateur Radio is a great many things to different people. For some it means a hand-held radio and chatting with mates on the local repeater, for others it means a full blown HF contest station with multiple antennas and radios, with integrated logging in a dedicated building. For others it means logging into a remote WebSDR and listening to the bands, decoding interesting signals, and license permitting, transmitting remotely across the internet. In other words, the "amateur radio" experience is unique to you. What you get from it is dependent on you and nobody else. As an aside, that's also true for licensing. If you have a "beginners" license, like my Foundation license, then it's entirely up to you to decide if and when you add extra privileges. "Foundations of Amateur Radio", well, its predecessor, "What use is an F-call?" emerged specifically in response to amateurs around me who continued to, let's be kind and call it "encourage" me to "upgrade" to a "real" license. Fifteen years on, I'm still a Foundation "beginner" and thus far I have yet to run out of things to do or talk about, so keep that in mind. I think that covers the disclaimers, no doubt more will occur to me as we continue on this journey. For the first decade or so of having a license, most of my activity was done in my car, a mobile shack of sorts. I didn't have access to a space where I could set-up a radio without running the risk of someone tripping over coax, or a landlord complaining within an hour of me erecting a temporary vertical. In other words, my mobile shack was born from necessity. It was helpful in exploring the limitless variation of operating positions, as-in locations and their impact on propagation, antenna performance, local interference, and plenty of other lessons. So, even if you don't have a permanent space to operate, there's plenty of amateur radio to go round. When I finally moved to a place where I had space, I started the process of putting together my shack. Initially it was pretty much integrated with my home-office. This sort of worked, but both the office and the shack suffered from this combination, so my first observation is that, in my experience, setting aside a dedicated space for a shack is a good idea. Now, right now, as I am telling you that, to the bottom right of my computer screen is the head of my Yaesu FT-857d, connected to a "RemoteRig", a pair of devices that replace the serial cable between the head and the radio with a network connection. The RemoteRig is connected to a WiFi router, which runs a dedicated wireless connection across the room to the WiFi router that's connected to the radio, sitting on what's left of my shack. It's how I run the weekly F-troop net. It's sitting there because I need to be able to access my computer to make log entries and track who's next in the round-robin discussion, and as I said, I've decommissioned my shack computer. Which brings me to the second point. Setting up a shack doesn't happen

Foundations of Amateur Radio Let's start with an observation, I'm a geek, have been all my life. Since my early teenage years that evolved as a predilection for computing. As you might already know, I became a radio amateur to essentially get away from computing. The reality turned out to be something else entirely. I discovered that the time of combining radio and computing had already begun when I joined the community. Like the evolution from spark-gap, through valves, transistors and integrated circuits, radio has come to encompass software, least of which through SDR, or Software Defined Radio. Why least? Over the years I've attempted to explain some of my fascination and wonder with software, but one aspect I've been unable to convey succinctly is the scope of software. I'm not talking about the fact that you find software inside your microwave oven, your car, your bathroom scales, but that hints at what underlies the phenomenon. If you're not familiar with spreadsheets, imagine a blank piece of paper with a grid drawn on it. Inside each square, or cell, you can put anything you want, a number, a label, a picture, a web address, a formula, a colour, borders, you name it. Your imagination is pretty much the only limiting factor. Now, here's where it gets fun. Once you have filled in the first cell, the next one follows. What this means is that once you've made the first decision, the next one becomes a little easier. Every time you make a decision, the number of options you have open to you become less and less, or to use another word, constrained. So what, you ask? Well, unlike a sheet of paper with a grid, a spreadsheet allows you to add rows and columns, at any point in your document. Doing that reduces the constraints, you have more options open to you. You can also add sheets, or even start a completely separate document. In other words, you have a playground open to you that is infinitely flexible. Writing software is like that, with bells on. Now, I'm not going to tell you to start learning how to write software, though truth be told, there's lots of things to like, and admittedly, frustration, that comes with doing so. Let's talk about that frustration. Once you make the first decision, the next one is more constrained. So, if you start with a blank sheet, you have infinite possibilities. Writing software is exactly like that. Here's the frustration. What's the first thing you should decide, because once you do, your options become reduced. So .. Bald Yak, if you're unfamiliar, the Bald Yak project aims to create a modular, bidirectional and distributed signal processing and control system that leverages GNU Radio. That little phrase hides a lot of complexity, but it already contains some constraints. GNU Radio is one, distributed is another and so-on. Let me share with you what my semi-blank piece of paper looks like. I've been quietly working on an idea to use my Pluto SDR to listen to amateur radio repeaters. Not just one, all of them, across 2m and 70cm. I came up with this idea as a real-life project that I'd like to implement with whatever Bald Yak is, or becomes. It has all the bits I care about right now, multiple frequencies, something that goes well and truly beyond what my Yaesu FT-857d can do, it taxes my skill set, it gives me something to make tangible and it hopefully moves the needle on the Bald Yak project. So, here's some variables to consider. The Pluto SDR has a computer on-board. There are reports that people have run GNU Radio programs on the Pluto itself. This is attractive since the amount of data involved with monitoring 2m and 70cm simultaneously is likely to exceed that of the USB port on the device. However, what I don't know is how much actual computing resources doing this will take to achieve and if a Pluto could actually do this. To give you an example. Imagine a massive fire-hose of data coming into my software and then processing that. Between memory and CPU constraints, I can't just decode the stream for each repeater, likely duplicating a whole bunch of calculations. While that consideration is on the table, decoding a dozen narrowband FM streams implies a dozen copies of the FM decoder software. Ideally this would be one actual piece of software, used a dozen times, rather than a dozen separate copies that will individually be maintained if something changes. For example, once I've built this, I might realise that I need to implement FM de-emphasis, a technique implemented in FM broadcasting to, among other reasons, manage artefacts associated with transmitting a signal over FM, perhaps a topic for another day. When you write software you do not want to have copies of the same software in multiple places. To use a spreadsheet equivalent, it's like putting a Tax rate in multiple places across your document, rather than storing it in a cell and referring to it in other formulas. That way, you can change it once and all the calculations will automatically be cor

Foundations of Amateur Radio The first step in solving any problem is recognising that there is one. In my case the name of that problem is "logging". Specifically the storage and collection of my amateur radio contact logs. Just to be clear, the actual process of logging is fraught .. what do you log, as in, which pieces of information are germane to the purpose of logging, do you log your own callsign, or do you only collect that once per session, do you log in UTC, or in local time, if you're logging in local time, do you record where you're logging, do you record what power level, which antenna, what radio, the battery voltage, you get the idea. Then there's .. when do you log? Do you log each and every session on-air, weekly nets, chat sessions on the local repeater, do you log the time when you establish the contact, once you've deciphered their callsign, or once the contact ends, and if you never wear a watch, how do you know what time it is? What do you log with? Is it using pen and paper, pencil and paper, on a sheet of A4, or A5, in a binder, in a scrapbook, in an exercise book, in a journal, a diary, on ruled, grid or on plain paper, or do you log with a computer and if you do that, using which of the seven gazillion logging packages that are available to you? I'm not talking about any of those things, though I suppose you could argue that I'm addressing one of the gazillion options, but stick with me. I have, sitting on my desk, fourteen different logbooks. That's not unreasonable, almost one for each year that I've been licensed. Except that these books are not in any way consistent, they're essentially bound pieces of scrap paper with log entries scribbled in the available space, sometimes I've reversed a spiral notebook, just so I can avoid the spiral with my writing hand, sometimes it's oriented in landscape, other times in portrait. Some are smaller than A5, others are foolscap and intended for accounting purposes. Next to that pile are too many empty logbooks, intended for future use. Why so many, you ask? Well it goes like this. You go to the office supply store to look for a suitable logbook. You buy it and try it. You use it for a bit and decide that you either love or hate it. If you hate it, you go back to the store to try and find another one. If you love it, your problem becomes finding an identical logbook. In a fit of inspiration, I loved the grid layout of my tiny spiral notebooks, and decided that this was the one for me, but they're no longer available, so instead I bought twenty A4 7mm grid exercise books with a soft cover, which I hate, and that was after trying to get a third Account Book Journal with a hard cover. There's also several A5 spiral bound books, but they're too chunky for portable operation and their spiral is annoying for logging. There's also various empty ring binders and paper ready for logging in the garage. Who knew that there are apparently multiple disconnected universes where so-called universal loose-leaf hole punched paper doesn't fit ring binders with more than two rings, I suppose that's like different implementations of the same version of ADIF, but I'll admit that I'm bitter and have digressed well off topic. I will say this, stationery and I clearly have an unhealed relationship. That's not the half of it. My computer has at least 208 ADIF and Cabrillo files on it. I say "at least", since that's the ones I found when looking for ADI, ADIF and CAB files. Removing identical files, nets me 171 text files which I'm pretty sure are all log files, 50-thousand lines, but that's with some having a one line per contact and others having a dozen, depending on which software wrote the file. It's going to take a moment, since those 208 files are scattered among 74 different directories. Then there's the files that "wsjt-x" and "fldigi" create, but right now I'm not sure what the extensions for those are, I think one is called "all.txt", and looking inside, it helpfully does not have a year in the logged data, so that's fun. My computer also has logs in "cqrlog", "xlog" and "VKCL", probably others. Then there's the logs I have online. The log for F-troop is a single spreadsheet, it has nearly 10,000 entries. I know that there's other files online and likely in other places like the various clubs I've operated at .. fortunately or not, most of those were done with the club callsign, so I'm calling those out of scope, at least for now. Then there's the entries in LoTW, Clublog, eQSL, probably QRZ and likely more. It all started out so innocently. I made my first contact in 2011 and forgot to log it. Since then I've been extolling the virtues of making sure that everyone around me logs their first contact. Meanwhile I've been pulling my hair out trying to make sense of the fragmented disaster that is represented by logging in amateur radio. I'll take responsibility for my own mess, but I have to point the finger at my predecessors who still cannot agree on what

Foundations of Amateur Radio The other day I was stuck in traffic behind a vehicle proudly proclaiming that it was "electric". I'd seen the model before, just never connected it with being available as an EV. I wondered how many other cars on the road turned out to have added an "electric" option to their line-up and how that evolution had just quietly, inexorably occurred. It started me thinking about the nature of the driving experience and what it would be like for someone who has never seen a petrol, or other fossil fuel burning vehicle, and what driver education might do to incorporate that. In my teens I first sat on a hotted up moped belonging to a friend, I was old enough to be legal, whilst he wasn't, so I got to ride his bike to school with him on the back, win-win for both. Later on, I learned to drive a car with a manual gearbox and as interest took me, I learned to drive a double clutch gearbox and got my heavy rigid truck license. I also learned to fly a plane, but that's besides the point. Stuck in rush-hour traffic, such as it is in Perth, it made me think about amateur radio licensing and education. Specifically, how do we incorporate change? When I was first licensed, my education included consideration for analogue television interference, including pictures of different screen patterns, their causes and remedies. Three years after I got licensed, almost to the day, the last analogue television transmitter in Australia was switched off on 10 December 2013, 57 years after the first transmissions started. While I retain little, if any, of the now, let's call it, esoteric information associated with that, it made me consider a wider picture in relation to the process of amateur radio education. New amateurs today are unlikely to be asked about analogue television interference, let alone be subjected to questions in their exam. Fair enough, information changes, evolves, becomes superseded or expires, and as a side-effect, I have some brain cells dedicated to analogue television, PAL, 625 lines total, 576 visible, horizontal and vertical synchronisation, white noise, you get the idea. As an aside, 78 on a turntable indicates a speed reserved for shellac records until the 1950s, seeing that we're dropping arcane knowledge. Oh, means NOP on a 6502, in case you're wondering. Although I don't have a specific list of what is currently being taught .. more on that in a moment .. I daresay that newly minted amateurs have a curriculum that has evolved with technology and legal requirements over the past 15 years. A tangible example is the fact that the Foundation Class in Australia is now permitted to use digital modes, something that changed after I was licensed, when on 21 September 2019, the regulator amended the Amateur License Conditions Determination, known locally as the LCD, with immediate effect. The point being that over time things change and education changes with it. This is all as expected. Here's my question. What about the rest of the community? What happens to someone who has been licensed for a decade, a generation, or more? Are they expected to gain these skills by osmosis or self-education? Should this process be dictated by the regulator, or should this be a community effort to bring everyone into the same decade? Should we revise how we educate our amateurs and make the education skill-set technology agnostic, should we be less prescriptive with the license, or should it achieve something else? One example in this space is an initiative called the Ham Challenge, which you can discover at hamchallenge.org. In case it sounds vaguely familiar, I've talked about this before. It's a list of 52 activities that you can take on to broaden your horizons and explore different aspects of our hobby. In its first year, I'm looking forward to seeing how it evolves. Is this the kind of self-training that we might encourage, or is there another way to achieve this? Is this something that occurs elsewhere in society and if so, how has that been addressed? I know for example in ICT there are endless certification courses, which I have to confess are in my professional opinion absolutely counterproductive, serving only to entrench vendor lock-in, not something that I think benefits the amateur community. I mentioned curriculum a moment ago. Another approach is to attend a licensing course and participate as part of your own self-education. Of course this will require cooperation from the educators, and we'd need to come up with some idea of how this might be useful. Is this something that benefits from attendance every five years, every decade, more, less? As a bonus side-effect, it will introduce new amateurs to old ones, and vice versa, perhaps facilitating a new resurgence of Elmering, or mentorship, that previously has been the hallmark of our community. Over the decade and a half or so that I've been licensed and writing weekly articles about the hobby and our community, I've made a conscious

Foundations of Amateur Radio Recently I spent some quality time digging into the origins of a word in common use. In doing so, I contacted the Postal Museum in the United Kingdom and received a lovely reply that included a photo of a document in their archive. The document, a Post Office Circular from Friday, December 30, 1904, number 1641, introduces a new service offered by the Post Office. Let me read to you what it says, and I quote: "Telegrams to and from Ships by Wireless Telegraphy. "(To be noted at Telegraph Offices only.) "With the present Circular is enclosed a list showing the wireless telegraph stations in the United Kingdom worked on the Marconi Company's system, and the hours up to which telegrams can be received at those stations for transmission by wireless telegraphy to certain ships fitted with Marconi apparatus. By another notice in this Circular, Postmasters and others concerned are requested to enter the names of the stations in the Code Book with the necessary particulars. Ships will be issued for insertion in the Post Office Guide. "On and from the 1st January, 1905, Telegrams may be accepted from the public on the following conditions:- "Subject to the Inland Regulations with regard to counting, the charge, which must be prepaid in the usual way by means of stamps, will be at the rate of 6 1/2d. [six-and-a-half pence] a word, with a minimum of 6s. 6d. [six-and-a-half shillings] per telegram. "The name of the wireless station will in each case pass as one word in the address. "The word 'Radio,' which is not charged for, should be telegraphed in the Service Instructions." When I read that, it made the hair stand up on the back of my neck. The introduction of a Wireless Telegram service, under the service heading of "Radio", with a photo of the actual document that introduced it into the world. I also learned that there's a dozen pennies in a shilling and over the years before decimalisation in 1971, the composition of coins changed, which made converting this into today's money interesting. As an aside, the Royal Society has a wonderful article: "The science of money: Isaac Newton's mastering of the Mint" Back to radio, this is 1904 bleeding edge technology and it's priced accordingly. The starting price for a radio telegram on new years day 1905: six bob and six; or three florin and sixpence; or a crown, a bob and a tanner; is worth just over 34 Great British Pounds today, that's just on 45 US Dollars, or nearly 69 Australian Dollars. That's the minimum price. The price per word, sixpence and halfpenny [sixpence hayp-ny] is just over 2 Great British Pounds today, nearly 4 US Dollars or almost 6 Australian Dollars. Compare that to the price of SMS, which started at about 21 cents here in Australia, today it's about 3 cents per message of 160 characters. This seems like a lucrative business to be in, but I digress, again. From my current, and ongoing research, it appears that until this point, the early 1900's, the word "radio" was always accompanied by another word, for example in this context, "radio telegraphy", another combination of the day is "radio active", as well as "radio tellurium", which today we know as polonium. Moving on, the response I received from the Postal Museum included other gems, including a reference to the "1904 Wireless Telegraphy Act", from the 15th of August, 1904, where I found something fascinating, from Section 2 paragraph 1: "Where the applicant for a licence proves to the satisfaction of the Postmaster-General that the sole object of obtaining the license is to enable him to conduct experiments in wireless telegraphy, a license for that purpose shall be granted, subject to such special terms, conditions and restrictions as the Postmaster-General may think proper, but shall not be subject to any rent or royalty." I think that's the birth of amateur radio licensing in the United Kingdom, right there. As an aside, because I cannot help myself, the definition for the expression "wireless telegraphy", is pretty interesting too, reminding me of a quote, variations going back to at least 1866, incorrectly attributed to Einstein that goes something like this: You see, wire telegraph is a kind of very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, and they receive them there. The only difference is that there is no cat. Seems that the drafters of the "1904 Wireless Telegraphy Act" had the same thing in mind when they wrote: "The expression 'wireless telegraphy' means any system of communication by telegraph as defined in the Telegraph Acts, 1863 to 1904, without the aid of any wire connecting the points from and at which the messages or other communications are sent and received" Now, as I said, I'm still working on this, because the word "radio" as a concept had to have been conceived before the Post Office Circular was written, printed

Foundations of Amateur Radio If you use a word often enough it starts to lose its meaning. The other day, during breakfast, well, coffee, whilst playing one of our start-the-day with a smile word games, the word "RADIO" turned up. I grinned and pointed out that this was my favourite word, to which my partner mentioned that in Italian, it's referred to as "La Radio", which made us both wonder where it actually came from, did the Italian language import the word, or export it, given that Guglielmo Marconi was Italian? A quick search advised us that it came from Latin, radius, meaning "spoke of a wheel", "beam of light" or "ray". Fully enlightened we finished our coffee and got on with our day .. except I couldn't stop thinking about this. Having recently spent some quality time looking into the history of the RF Circulator, I figured searching the patent records might be a solid way to get some handle on where this word "radio" came from. Initially Google Patent search unearths the oldest as being from 1996, not very helpful. Adding 1900 as the end date filter turns up a radio cabinet patent with a filing date of 1833, except that it was published and granted in 1931, which is confirmed by the patent itself. This level of corruption in the data affects at least a dozen patents, but I daresay that there's plenty more like that. 1857 turns up a patent with the word "broadcasting", in the context of "broadcasting guano", so, nothing much has changed in nearly 170 years, but I digress. Adding quotes to the search term unearths a patent from 1861, apparently iron roads, locomotives, large slopes and small radio curves relates to the other meaning of the word radius, in Spanish. 1863 gives us ruffle stitching, "made upon the radio", but the patent is so corrupt that it's pretty much unreadable. 1871 unearths an electromagnetic engine, but the text has so much gibberish that I suspect that the word "radio" is a happy accident. 1873 shows us a "Wireless signalling system", bingo, the patent shows us transmitter and receiver circuits, antennas, messages and frequencies and a whole bunch of relevant radio information, except that the date on the patent itself is 1919. And you wonder why people argue about who invented what when? I'll spare you the gas apparatus, petrol lamps with cigar cutter, running gear for vehicles and bounce to 1897, "Method of and apparatus for converting x-rays into light for photographic purposes", the first occurrence of "radio", in the form of "radiograph", complete with pictures of the bones of a hand drawn meticulously from presumably an x-ray. I confess I'm not convinced. Using the United States Patent and Trademark Office search for the word radio gives you 54,688 pages with 2.7 million records, ordered in reverse chronological order with no way to skip to the last page. The World Intellectual Property Organisation finds the same Spanish iron paths patents, but unearths "A Differential Arrangement for Radio Controlled Race Cars" from 1900, but inside we discover it's really from 1979. Seems this level of corruption is endemic in the patent field, wonder who's benefiting from this misinformation? Meanwhile, still looking, I discovered the Oxford English Dictionary, which claims that the earliest known use of the word "radio" is in the 1900's, but the earliest evidence is from 1907 in a writing by "L. De Forest", but you are granted the privilege of paying them to actually see that evidence .. really? On 18 July 1907, Lee de Forest, made the first ship-to-shore transmissions by radiotelephone, which adds some credence to the claim, but I have to tell you, I'm not particularly convinced. Taking a different approach, starting at Guglielmo Marconi, his first efforts in 1894 showed the wireless activation of a bell on the other side of the room. Six months later he managed to cross 3 kilometres realising that this could become capable of longer distances. The Italian Ministry of Post and Telegraphs didn't respond to his application for funding, so in 1896, at the age of 21, moving to Great Britain, he arrived in Dover where the customs officer opened his case to find various apparatus, which were destroyed because they could be a bomb. Lodging a patent "Improvements in Transmitting Electrical impulses and Signals, and in Apparatus therefor", was the first patent for a communication system on radio waves. It was granted a year later. One problem. It doesn't have the word "radio" in it, instead it talks about "a Hertz radiator", so close. So, we've narrowed it down to somewhere between 1896 and 1907, that's an 11 year window. Some observations. De Forest founded a company called "the Radio Telephone And Telegraph Company". It's unclear exactly when this happened, it collapsed in 1909 and was founded after disagreement with management of his previous company, apparently on 28 November 1906. A quick aside, apparently in 1881, Alexander Graham Bell used the word radiophone for the first time, which

Foundations of Amateur Radio Recently I explored the use of a radio device aptly described by a fellow Aussie Electronics Engineer, "ozeng", as "Absolute witchcraft." .. I'm talking about an "RF circulator", one of which is sitting quietly on my desk, roughly 60 mm square, 30 mm thick, weighing in at just under half a kilogram, unexpectedly with a 200 year history. Let the spelunking commence .. The moment you start reading the "Circulator" Wikipedia page, you'll see this sentence: "Microwave circulators rely on the anisotropic and non-reciprocal properties of magnetised microwave ferrite material.", with a helpful reference to "Modern Ferrites, Volume 2: Emerging Technologies and Applications", a 416 page reference that promises to dig into the nitty-gritty, showing 55 hits for the word "circulator". Anisotropic you ask? It's the property that describes velvet, rub it one way, it's smooth, rub it the other way and the hair stands up on the back of your neck. Wood is another example, easier to split along the grain than across it. While we're at it, reciprocity in physics is the principle that you can swap the input and output of a linear system and get the same result. If you know me at all, it should come as no surprise that I went looking for an inventor. There's over twelve-thousand patents referring to a "circulator", including more than a handful relating to Nuclear reactors. In 1960, a prolific Jessie L Butler came up with patent US3255450A, "Multiple beam antenna system employing multiple directional couplers in the leadin", which states: "This circulator has the characteristic that energy into one port will leave another port to the exclusion of a third." If you recall, that's the exact phenomenon I used to describe the "RF circulator" on my desk. So, job done, we have our inventor. Not so fast. The patent goes on to say: "Circulators of this type are discussed in an article 'The Elements of Nonreciprocal Microwave Devices' by C.Lester Hogan in Volume 44, October 1956, issue of Proceedings of the IRE, pages 1345 to 1368." The IRE is the Institute of Radio Engineers. I found a copy of that tome, thank you worldradiohistory.com, which includes the following sentence: "Until a few years ago, all known linear passive electrical networks obeyed the theorem of reciprocity. Today several different types of passive nonreciprocal microwave networks are in practical use". A footnote refers to an article by Lord Rayleigh, "On the magnetic rotation of light and the second law of thermodynamics" and includes images of an optical one-way transmission system from 1901. In that 1901 article, Lord Rayleigh in turn refers to a paper published sixteen years earlier in which he observed that light polarisation can be made to violate the general optical law of reciprocity, using a system that consists of two so-called Nicol prisms, a crystal that can convert ordinary light into plane polarised light, invented by William Nicol in 1828. Using two prisms, arranged at a 45 degree angle, you can make light go through it in one way, but not the other. Lord Rayleigh, also known as John William Strutt, in a very sparse footnote, states: "That magnetic rotation may interfere with the law of reciprocity had already been suggested by Helmholtz." Further digging gets me to an 1856 publication of the "Handbuch der physiologischen Optik", or the handbook of the study of how the eye and brain work together, where Helmholtz says that, translated from German, "according to Faraday's discovery, magnetism affects the position of the plane of polarization." This gets us to 1845, where Michael Faraday experimentally discovered that light and electromagnetism are related. His notebook has the following sentence, paragraph 7718 written on the 30th of September 1845: "Still, I have at last succeeded in illuminating a magnetic curve or line of force and in magnetising a ray of light." Today we call that the "Faraday effect" The best part? You can read Michael Faraday's diary, right now, and see the whole thing. So, who then invented the RF circulator? From Mastodon to Circulators, to Modern Ferrites, to Nonreciprocal Microwave Devices, to Multiple beam antennas, to Magnetic Rotation, to Optical Reciprocity, to Nicol prisms, to the Faraday effect, this is the perfect example of standing on the shoulders of giants, and the result sits as a little box on my desk. Just so you don't feel left out, your mobile phone likely has one of these devices on board. I'm Onno VK6FLAB

Foundations of Amateur Radio The other day I saw a post by fellow amateur Gary N8DMT who mentioned an "RF circulator" and a PlutoSDR in the same sentence. Amplified by a response from a fellow Aussie Electronics Engineer, "ozeng", who helpfully added a link to a Wikipedia article about circulators, it finally twigged that I had such a gadget in my possession and for the first time I realised how I might use it. Now, before I continue, I'll preface this with a disclaimer, this is a hand-wavy description of what this very interesting device does. "ozeng" calls it "Absolute witchcraft." and that's an apt description if ever I've heard one. Imagine for a moment a radio with separate transmitter and receiver connectors, attached to the same antenna using a T-piece, as-in, there's a run of coax coming from each connector, joined together with a T-piece, which in turn is connected to an antenna. The aim of this, don't do this at home contraption, is to avoid the need for two antennas, but, and it's a big one, doing this will very likely destroy your receiver the moment you transmit for the first time, because likely half the transmission will go to the antenna, while the other half makes its way to the receiver, which is not going to be something you want to happen, unless you like the smell of magic smoke. You might think that adding an attenuator, something that reduces the power on the receive port would help. Well, yes, it would, but as a side-effect, it would also reduce the signal coming from the antenna. At that point you'll decide you need a switch. Initially you might switch this manually, but that's a pain if you're wanting to transmit and receive continuously and need to remember in which position the switch is in. The next step is to use an electronic switch, like a relay. It can trigger based on some signal from the radio when it's transmitting and turn off the receive path during a transmission. This raises an issue with delay. Do you trigger just before you hit the PTT, as-in, time-travel, or do you delay the transmitter until after the relay has switched, which will cut off the beginning of your transmission? You'll likely have heard this kind of issue when listening to a station using an external amplifier. Their signal either jumps from low power to high power after they key up, or you miss the beginning of their callsign. Not to mention that if you get the delay wrong, you blow up the receiver, fun for people watching, not so much for the equipment owner. Even if you get the timing right, you cannot transmit and receive at the same time. Of course an obvious solution is to have two antennas, but soon you'll discover that when you're transmitting and receiving on the same frequency, even using two antennas, you'll have the exact same issues. It's why the local 10m repeater here in Perth, VK6RHF, has the transmitter in one location and a receiver 12 km away, connected to each other via a 70cm radio link. Other solutions in this space are cavity filters, duplexers and diplexers. These all require that the transmit and receive frequencies are different and the equipment is generally tuned to a specific pair of frequencies. Physically cavity filters can be massive, not to mention fragile. So, solving the issue of having a transmitter and receiver together on the same frequency is one that is challenging to say the least. It's a common issue, think about mobile phones, satellites, broadcast transmitters, and even your own amateur radio station. An RF circulator is a device that solves this in an extremely elegant way. For starters, it's a passive device, which means that you don't need to power it, there's no moving parts, no switches, no delays, no external controls, it's a box, generally with three sockets or ports, though versions exist with more. At a basic level, it works like this. A signal inserted into port one, will only come out of port two. Similarly, a signal into port two, will only come out of port three and finally, a signal into port three, will only come out of port one. Think of it as a one way roundabout. How is this useful you might ask. I'll illustrate by plugging in three things, connect port one to an antenna, port two to a receiver and port three, a transmitter. When you transmit into port three, the signal only goes to the antenna, leaving the receiver safe and happy. Similarly, any antenna signal will only go to the receiver. So, how does this work? Remember, hand-wavy. Essentially, it's based on the idea that radio waves travelling in one direction combine and waves travelling in the opposite direction cancel. Different types of circulators achieve this in different ways and come in different sizes as a result. The RF circulator I have is roughly 60 mm square, 30 mm thick, weighing in at most of half a kilogram and as far as I know, intended for operation around 850 MHz. If I recall correctly, it came out of a CDMA mobile phone tower. The parameters that describe an RF circu

Foundations of Amateur Radio The other day I received an email from Frank K4FMH asking me about an idea I'd worked on some time ago, namely the notion that I might monitor solar flux at home using a software defined radio. At the time I was attempting to get some software running on my PlutoSDR and got nowhere fast. Before I continue, a PlutoSDR, or more formally an ADALM Pluto Active Learning Module by Analog Devices, is both a computer and a software defined radio receiver and transmitter in a cute little blue box. I've talked about this device before. It's an open design, which means that both the software and hardware are documented and available straight from the manufacturer. Out of the box it covers 325 MHz to 3.8 GHz. You can connect to a PlutoSDR using USB or via the network, wireless or Ethernet, though I will mention that neither of those last two is currently working for me, but more on that later. Encouraged by Frank's email, I set out to explore further and came across a 2019 European GNU Radio days workshop, which discussed some of the tools that are available for the PlutoSDR, accompanied by two PDF documents walking you through the experience. One comment around why the PlutoSDR uses networking as one of the connectivity options spoke to me. From a usability perspective, networking makes it easier to access the PlutoSDR from a virtual machine, since most of the time that already has network connectivity, whereas USB often requires drivers. As you might recall, network connectivity is one of the many things that I'm trying to achieve with a project that I'm calling Bald Yak, since by the time we're done, there's not going to be much hair left from all the Yak Shaving. The Bald Yak project aims to create a modular, bidirectional and distributed signal processing and control system that leverages GNU Radio. As a result, I set about trying to actually walk myself through those PDF tutorials .. and got stuck on the first sentence on the first page, which helpfully states: "The necessary prerequisites have been installed on the local lab machine." It went on to supply a link to a page with instructions on how to acquire those very same prerequisites. Two days later, after much trial and error, I can now report that I too have these installed and because I cannot help myself, I made it into a Docker container and published this on my VK6FLAB GitHub page. To put it mildly, there's a few moving parts and plenty of gotchas. As an aside, if you think that installing Docker is harder than installing these tools, I have some news for you .. trust me .. by a long shot .. it's not. Right now I'm working on writing the documentation that accompanies this project such that you can actually use it without needing to bang your head against the desk in frustration. Mind you, the documentation part of this is non-trivial. For reasons I don't yet understand, my Pluto does not want to talk to the network directly over either WiFi or Ethernet, and connecting over USB through a virtual machine inside a Docker container is giving me headaches, so right now I'm connected across the network to a Raspberry Pi that's physically connected to the Pluto. As a result, I can now use the tools inside my Docker container, connected to the Pluto through the Pi and if you're curious, 'iiod' is the tool to make that happen .. more documentation. At this point you might well ask, why bother? This is a fair question. Let me see if I can give you an answer that will satisfy. Monitoring solar flux typically occurs at 2.8 GHz, which is outside the range of RTL-SDR dongles which top out at about 1.7 GHz. For the PlutoSDR however, it's almost perfectly within the standard frequency range. One of the tools that is introduced by the talk is an application called 'iio-scope', which as the name suggests, is an oscilloscope for 'iio' or Industrial I/O devices, of which the PlutoSDR is one. As an aside, the accelerometer in your laptop, the battery voltage, the CPU temperatures, fans, and plenty of others, are all 'iio' devices that you can look at with various tools. So, once I've finished the tutorials, I suspect that I will understand a little better how some of the various parts of the PlutoSDR hang together, and I can set it up to monitor 2.8 GHz. Of course, that's only step one, the next step is to make a Raspberry Pi record the power levels over time, better still, record it on the PlutoSDR itself, and see if we can actually notice any change .. without requiring anything fancy like a special antenna, some massive filters, a special mount and all the other fun and games that no doubt will reveal themselves in good time. It also means that, if I got this right, I have the beginnings of the bits needed to get the PlutoSDR to talk to GNU Radio. Why? Because I can, and because Frank asked, also Yak Shaving. I'm Onno VK6FLAB

Foundations of Amateur Radio The other day I went on my first POTA or Parks On The Air adventure, this time I was on my own. If you recall, my power company announced yet another planned network outage and I felt that I could use this time without electricity to my benefit, for a change. As is traditional, I did all the prior planning to prevent pretty poor performance. I made a list, checked that all the items on the list were in my kit, packed the kit days before, put it all ready to go in the hallway the night before, packed the car on the day and set out on my adventure. I will confess that I was slightly more sweaty than anticipated when I set off because the umbrella in the boot of my car has a nasty and recurring habit of getting in the way, specifically it stops things from getting pushed right to the full depth of the boot. Mind you, it wasn't until I started getting agitated that I realised that it wasn't the umbrella's fault entirely this time, since as it turns out, the folding chair that I was attempting to jam in place doesn't actually fit longways into the boot. Anyhoo, I set off and visited the local petrol station. I was not prepared for a customer to spend 15 minutes dribbling the last bit of diesel into their pretend Sports Utility Vehicle, but he looked like he was up for a fight, so I smiled sweetly and waited for him to pay and move his box on wheels. After paying for my own fuel and driving off, the pressure in my bladder had gotten beyond the "cross your legs and hope for the best" stages and I swiftly made my way to the nearest shopping complex where a local pharmacist helpfully told me that there were no toilets in the building and that the local hotel or fast food joint were the place to relieve the pressure. One problem .. they were both closed. At this point I was in pain, and discovered that I couldn't read the screen on my mobile phone in the lovely sunlight, because it was set to battery saving mode, since my charger was at home where the power was out. After disabling the battery saving mode I opened the local public toilet map shortcut on my phone, and discovered that fortunately the shortcut still worked, opening up my default browser, which suddenly didn't want to display a map. Copied the URL to another browser, still in pain, finally a map. Click on the nearest icon and it navigates me there from Darwin, or over 4,000 km from where I actually am. Luckily it has the GPS location which I copy and then paste into my mapping app, and I can finally navigate to the nearest toilet. Several comment worthy navigation moves later, I drive into the car park, lock the car, painfully shuffle to the building, do my business in the very clean facilities and then decide that I should just stop, sit, and take a breath. So, I get in the car and discover that my partner was right when they heaped scorn on our newly acquired thermos cup. It really does hurt your nose when you try to drink from it and the sharp edges in your mouth do nothing to make the experience joyful. Meanwhile there's some trucks moving around in the car park and a guy walks up to the car to ask me if I can move because they want to move a third, or was it forth, truck into the space. I swallow my sip of restorative coffee, wipe the now wet bridge of my nose, and move the car, only to be blocked from leaving the exit thanks to the slowest reversing truck I've ever encountered, one who then proceeds to sit at the next intersection for five minutes without indicating where it was going. Are we having fun yet? I finally made my way to the main road where I attempt to calm my nerves with the help of a Morse code edition of my podcast. It's been the only exposure I've had to Morse for way too long. This accompanies me to my first destination, breakfast. I'm going to skip past the drivers in the centre lane driving at 10 km per hour below the posted speed limit, or the ones who think that jumping out of a side street in front of you is normal and safe driving practice. At every traffic light I celebrate the pause with a sip from my coffee and a furtive wipe of my nose which is being assaulted by the lid of the cup. I arrive at my breakfast destination and fear the worst. Their car park is almost empty. I've never seen it this quiet and I didn't check to confirm that they were open, or not. I look at my map application and remember to turn my phone back to battery saving mode. According to the Internet, my cafe is open, so I cross my fingers and get out of the car. To my delight, they are absolutely open, make me a lovely breakfast and provide the needful for lunch too .. I have a big day planned after all. After enjoying breakfast and hot chocolate, with two marshmallows, I get back in the car and navigate to my planned set-up location. As I drive into the park I notice something that I hadn't the last time I was here. I'm descending, as-in, the deeper into the park I go, the more I go downhill. That in and of itself isn't a

Foundations of Amateur Radio Recently my local power company notified me of a planned network outage, that's code for, we're turning off the power and your choice is to deal with it. If you've been paying attention, you'll note that this is not the first time this has happened in recent times. On this occasion I want to make a difference and actually use the day wisely. Coincidentally, the 750th instalment of F-troop is coming up and traditionally we try to find an excuse to get outside and set-up a station in a local park somewhere. If you recall, I recently went outside and came across a new park, one with picnic tables, gazebos, toilets and all the mod cons required for a party. Combine these unrelated events and you end up with testing the idea of running F-troop, a weekly net for new and returning amateurs, from this park, which also neatly turns that into a POTA or Parks On The Air activity, which raises several logistical questions. The first one being, what is the radio noise like in this park, followed shortly by the question, can I hit my local 2m repeater, any 2m repeater, or the local 10m repeater? If the answer to those questions is unsatisfactory, I might be required to rethink my plans. Combining those questions with a power outage at home seems like the perfect excuse to go out into the bright day to get on air and make some noise. One challenge. Having removed my radio from my car several years ago to accommodate the replacement of the transmission, I never did replace it and never used my radio in the car again, which truth be told is not a situation I ever imagined when I first installed it many years ago. This leads me to creating a list, which should come as no surprise, a list with what I need to bring as a minimum requirement to test the questions I need answers to. I will confess that the "making a radio packing list" skill-set has atrophied in recent times, so I started small. I'll need a radio, and a suitable antenna, in my case, at least two, one for 2m and one for 10m. Then there's the question of power, at which point I discovered that my trusty portable sealed lead acid batteries have finally died, not bad after 15 years, well, 12 years of regular use. Likely they would have continued to be of service if I'd used them in the past three years, mainly hampered by the death of my 12 volt battery charger. If you feel like I'm going off track, you'd be right. That was the exact experience I had when I started building my list. I added a digital multimeter, an antenna analyser, an antenna tuner and coax, then realised that I needed to check if the coax adaptors were the right ones and so it continued. The upshot is a preliminary list with 15 items on it, in various stages of fully populated, for example, I know I have a 2m and 70cm antenna in the garage, but I haven't touched it in years, so I need to go find it, and the battery in my digital multimeter needs checking, you get the idea. It's a good thing I started this caper well over a week before the planned outage, so at least I have half a fighting chance to get it to the point of usefulness before my screen turns black due to the threatened lack of electricity. It occurred to me whilst I was in the middle of this extended list creation process, that I was essentially replicating what I might have experienced the very first time I went outside with my station in 2011. In coming to that realisation, the stress levels that were building steadily at that point, pretty much dissipated with the understanding that I'd already done this and survived the experience. In other words, there was nothing worth stressing about. So, this leaves me with a question for you. What does this process look like for you, how do you prepare to get on-air and make noise, what steps do you take and what do you avoid, are there things you might share with a new amateur and if so, how will you do that? I contemplated sharing the list in a public place, but realised that the power of the list isn't the items on it, but in the process of making it, so, no list, but the notion that you too can do this, and if it transpires that you forgot something, there's always the next adventure. I'm Onno VK6FLAB

Foundations of Amateur Radio The pursuit of amateur radio is a glorious thing. On the face of it you're forgiven if you think of it as a purely technical endeavour. Far be it for me to dissuade you from that notion, but permit me to expand into other areas that rarely get a mention when we discuss this amazing hobby. It's the place where you go to communicate with other people, who live a different life, doing the things that they enjoy. It's also the place for finding an excuse to go outside and set-up your station on the side of a mountain, or a park, a museum or a lighthouse. Then there's the joy of finding new friends who introduce you to other aspects of life, super computing, the medical field, tow truck driving, radio astronomy and electronics, to name a few. While I was the first person in my school to save up their summer job earnings to buy their own computer, a Commodore VIC-20, I never did come across this. "It is pitch black. You are likely to be eaten by a grue." is a phrase that might mean something to you, or not. To set the stage, it's the 1960's, you're a science fiction author and you need a ravenous predator. With origins in Danish and Norwegian, "grue", from gruesome, seemed to fit the bill for Jack Vance while was writing his Dying Earth series, mind you, Robert Louis Stevenson used it in 1916 in a short story called "The Waif Woman", writing "and a grue took hold upon her flesh", which is more gruesome than predator. Flash forward to 1977, you're writing an adventure game for a PDP-10 mainframe computer whilst, let's call it studying, at MIT, and you need a way to stop people wandering off the map, and so the text adventure game "Zork" got its famous phrase. I'm mentioning this because I wondered if anyone had used their love for Zork as an excuse to set-up a server on HF radio that you could play with. I'll confess that I spent way too many hours looking at this and it appears that you can use the software "direwolf" as a way to get packet radio to work across amateur radio without needing anything more than a radio and a computer with a sound-card. There's even an article by Rick Osgood titled: "How to Setup a Raspberry Pi Packet Radio Node with Zork", though I will mention that it relies on hardware to connect to a radio, rather than use "direwolf". There's a few moving parts, but it looks like this is totally doable, there's already Docker containers for both Zork and direwolf, even a container called "packet-zork", and a multi-user version called "MultiZork", so how hard can it be? I jest. As an aside, because I'm a geek and I can, there's a common misconception that a Docker container is equivalent to a virtual machine. For lots of reasons, that's not true. A better way is to think of it as a security wrapper around an untrusted application. Speaking of untrusted, while we're all essentially bipedal lifeforms with a similar set of attributes, on a daily basis we seem to discover more and more reasons to find fault or demonise differences. Contrast this within the global community of radio amateurs, where we have this "weird" activity that we all seem to share. I think that the most under-reported, perhaps even undervalued aspect of our hobby is that it's an excuse to talk to someone else. It's like a force of attraction, the glue, the one starting point that you know another amateur has in common with you. So, next time you venture outside, either in real life, or virtually, consider, at least for a moment, that there are other radio amateurs among us, also having fun. I'm Onno VK6FLAB

Foundations of Amateur Radio The other day I came across an article written by programmer, artist, and game designer "blinry" with the intriguing title: "Fifty Things you can do with a Software Defined Radio". Documenting a weeks' worth of joyous wandering through the radio spectrum it explains in readily accessible terms how they used an RTL-SDR dongle to explore the myriad radio transmissions that surround us all day and every day. As you might know, I've been a radio amateur since 2010 and I must confess, even with all the things I've done and documented here, there's plenty in this adventure guide that I've yet to attempt. For example, when was the last time you decoded the various sub-carriers in an FM broadcast signal, including the pilot tone, the stereo signal, station meta and road traffic information? Have you ever decoded the 433 MHz sensor signals that your neighbours might have installed, weather, security and other gadgets? Or decoded shipping data, transmitted using AIS, or Automatic Identification System, and for context, we're only up to item 12 on the list. One of the biggest takeaways for me was that this is something that is accessible to anyone, and is a family friendly introduction to the world of radio that amateurs already know and love. The article touches on various applications that you might use to explore the highways and byways of the radio spectrum, including SDR++, SDRangel, WSJT-X, QSSTV, and even mentions GNU Radio. With enough detail to whet the appetite, I learned that SDRangel, developed by Edouard F4EXB and 70 other contributors, has all manner of interesting decoders built-in, like ADS-B, Stereo FM, RDS, DAB, AIS, weather balloon telemetry, APRS, even VOR. As it happens, you don't even need to install SDRangel to get going. Head on over to sdrangel.org and click on "websdr" and it'll launch right in your browser. Once you're up and running, you can use your RTL-SDR dongle to start your own small step into the wide world of radio, amateur or not. Sadly the PlutoSDR does not work on the experimental web version, so I had to install SDRangel locally. That said, I did get it to run and connect to my PlutoSDR which worked out of the box. The user tutorial is online and the Quick-Start walks you through the process of getting the software installed and running. One thing that eluded me for way too long is the notion of channel decoders. Essentially you configure the receiver, in my case a PlutoSDR, and start it running. You'll be able to change frequency and see the waterfall display, but nothing else happens, and there's no obvious AM, FM or other mode buttons you'd find on a traditional radio. Instead, you'll need to add a channel decoder, cunningly disguised as a triangle with circles at the corners with a little plus symbol at the top. You'll find it immediately to the left of your device name. When you click it, you're presented with a list of channel decoders, which you can add to the work space. This will do the work of actually decoding the signal that's coming into the software. SDRangel also supports M17, FreeDV, RTTY, FT8 and plenty of other amateur modes, and includes the ability to transmit. Oh, did I mention, it can also connect to remote kiwisdr receivers? I have to say, it's a joy to see software that I've previously looked at and admittedly shied away from, actually doing something with the radio spectrum around me. I will confess that SDRangel has a lot of moving parts and it's like sendmail, user friendly, just picky whom it makes friends with. So, time to dig in, play around and bring it to the next amateur radio field day "Show and Tell" and share with the general public just how interesting the radio spectrum around us can be. I'm going to work my way through the 50 items, just for giggles. What are you waiting for? I'm Onno VK6FLAB

Foundations of Amateur Radio The other day I went for a walk, I know, shock-horror, outside, daylight, nature, the whole thing, in a local national park, for the first time in too many years. Almost immediately I noticed that this would be an excellent location for an activation. If you're not familiar, it's an amateur radio excuse to set-up a portable station in a new location, in this case, potentially something called POTA, or Parks On The Air, but you don't need to find a formal activity with rules to get on air and make noise. I commented on how easily accessible it was, that it had picnic tables, gazebos for shelter, nearby toilets, free BBQs, ample parking, lots of open space, and no overhead power lines. I saw one solar panel on a pole and no evidence of any other electrical noise sources. It wasn't until later that I realised the act of noticing this, in that way, with those details, is not something I would have done before becoming a radio amateur. I'd have looked at the same location, considered its beauty and serenity and perhaps in passing considered that we could have a family gathering, or a place to come back to when I wanted some peace and quiet, or a place where I might have a BBQ with friends. Not that those things went away, just that I noticed other things, now that I'm an amateur. It made me consider just how much this hobby has irrevocably changed me. I know I've mentioned this before, since becoming an amateur I cannot walk down the street without noticing TV antennas pointing in the wrong direction, but this change in me is not limited to that. Now I cannot help discussing the best place to put a Wi-Fi base station in a building, or thinking about and checking on solar activity, wondering about battery capacity, RF interference, trees to potentially use as sky-hooks for wire antennas, power company substations, pole-top transformers, random weird and wonderful antennas and probably more. The point being that this hobby opens the door to a whole new way of looking at the world and I don't think I've overstated, if I say that amateur radio has literally changed my world view. In considering this, I suspect that it's related to a cognitive bias known as the Frequency Illusion, where you notice a specific concept, word or product more often after becoming aware of it. You might for example have experienced this with the brand or model of radio you use and suddenly discovered that there's lots of other amateurs talking about that particular piece of equipment. I've seen this with recurring topics during the past fourteen years of the weekly F-troop net. For example, every couple of years someone discovers magnetic loop antennas and starts talking about how they've built or bought one. The conversation inevitably goes past variable capacitors, through air variable capacitors, on to vacuum variable capacitors and then the conversation generally stops. While it's happening, multiple people come on the same journey, only to follow the exact same path. Several years later, the cycle repeats. Don't misunderstand, I welcome the discussion, point people at relevant resources and help them on this journey. I'm commenting on the recurrence of the journey, not the nature of it because it's easy to take this example and hold it up as "there's nothing new in this hobby", but nothing could be further from the truth. In my opinion, the level of complexity associated with radio communications is infinite and anyone, including you and I, can contribute to the discovery associated with it. So .. what things have you noticed that were caused by this somewhat eccentric hobby and perhaps the phenomenon of Frequency Illusion? I'm Onno VK6FLAB

Foundations of Amateur Radio I've owned a Yaesu FT-857d radio since becoming an amateur and at the time I was absolutely blown away by how much radio fits inside the box. It's smaller than most of the commercial radios I'd seen when I bought it. I came across a video by Michael KB9VBR, the other day showcasing a wooden cigar box with a complete, well, almost complete POTA, or Parks On The Air, activation kit. I say almost, since Dave KZ9V, the owner of the kit, points out that the box doesn't contain an antenna. It made me wonder how small is small? According to RigPix, the lightest transmitter on an amateur band, in this case, the 5 GHz or 5cm band, is an Amateur TV transmitter. Weighing in at 3.9 grams. The Eachine TX-06 is capable of FM with about 18 MHz of bandwidth with an audio sub-carrier. Of course, that's not a transceiver, but I thought it worth mentioning in case you needed an excuse for something tiny in your shack, besides, as far as I can tell, there's never too much Amateur TV in the world. I've built a crystal radio on a breadboard which is tiny, but it doesn't transmit, so to set the stage, I think we need to limit ourselves to transceivers, that is, a device capable of both transmitting and receiving, on amateur bands. Before continuing I'd like to express my thanks to Janne SM0OFV, for the rigpix.com database that he's been maintaining, in notepad, since 2000. Without the invaluable information documented for the currently 7,512 radios, I'd be spending an awful lot of time hunting for information. Moving on, the FaradayRF board is a transceiver, capable of using 900 MHz or the 33cm band. It comes in at 30 grams, but without a computer it's a circuit board with potential. The PicoAPRS by Taner DB1NTO, is a 2m transceiver specifically for APRS, weighs in at 52 grams and similar in look and a third of the weight of an Ericsson T18 mobile phone. Speaking of mobile phones, the PicoAPRS does WiFi and Bluetooth, can pair with your phone and act as an AX.25 modem. I'll confess, I'm drooling. Moving right along, for 70cm there's a Rubicson Walk 'n' talk, weighs in at 65 grams. Mind you, the RigPix database puts this under the "License-free / PMR446" section which comes with a sage warning, check your local laws before transmitting. There's a few Alinco DJ-C models for different markets that operate on 2m or 70cm, weighing in at 75 grams. The ADALM Pluto weighs 114 grams, but you'll need a USB power supply of some sort to make it do anything. It can operate between 70 MHz and 6 GHz, but the user interface is limited to a single button and LED, so if you want to interact with it, you'll need some external technology. Moving on to HF transceivers, weighing in at 199 grams, without the bag, but all the options, is the Elecraft KH1. Transmits on 40m, 30m, 20m, 17m and 15m and receives between 6 and 22 MHz. It's CW only, but you can receive SSB. If CW isn't your thing, RTTY and PSK can be used on the 40m band with a Silent System Handy PSK 40. Presumably the Handy PSK 20 runs on 20m. Both weigh in at 250 grams. The Zettl P-20xx SSB does SSB, AM, FM and CW, transmits on 10m, 11m, 12m and 15m as well as the MARS frequencies and receives between 14 and 30 MHz, weighs 300 grams. Even comes with CTCSS. Another Elecraft model, the KX2 weighs in at 370 grams, does 80m to 10m and the WARC bands, does SSB, CW and data. Mind you, you'll also need to add the weight for the microphone and paddles, and factor in a computer if you want to do more than PSK and RTTY. The Expert Electronics SunSDR2 QRP does 160m to 10m, the WARC bands and 6m. Weighs in at 500 grams, has a network port and two independent receivers. Operates at 5 Watts. There's no user interface, unless you count the reset and power buttons, so I'm not sure if it can operate on any mode with just a microphone, but given the "Depending on software" disclaimers throughout, I'm going to guess you'll need to bring a computer to make it sing. The Risen RS-918SSB does all HF amateur bands between 160m and 10m, has a user interface and display, even a big tuning knob, has built-in FreeDV and does FM, SSB and CW. I'd hazard a guess that this is the lightest self-contained transceiver that you can take out on a POTA mission to a park. Weighs 623 grams and comes with an internal battery. The Elecraft KX3 also does 160m to 10m, and 6m, with a 2m option. Weighs in at 680 grams, but that doesn't include any options. And finally, we pass 1 kilogram and hit 1,100 grams and discover a radio that does all bands and modes, the Icom IC-705 with a battery, but no antenna. The Yaesu FT-817, FT-817dn and FT-818 weigh 70 grams more, but that weight includes both a battery and antenna. Of course there are other options. For example, there's the (tr)uSDX by Manuel DL2MAN, and Guido PE1NNZ, does 80m, 60m, 40m, 30m and 20m, CW, SSB, AM and FM. Comes in a kit, weighs 140 grams. It's not on RigPix, so I only know about it because it was mentioned by Dave KZ9V. Similarly, I bumped in

Foundations of Amateur Radio Over the past nine months or so I've been working on a project that I've called Bald Yak. If you're unfamiliar, the Bald Yak project aims to create a modular, bidirectional and distributed signal processing and control system that leverages GNU Radio. One of the, admittedly many, challenges I've set myself is getting data from a radio receiver into GNU Radio across the network, preferably the Internet. Today I can report a small step in the right direction and frankly I can't contain my excitement. Now, I need to acknowledge that I'm geeking out here. It's hard to contain excitement when you find something that seems to speak your language. It also means that I realise that I run the very real risk that I'm going to lose you before you get to why this is a milestone, so let's put that up front before I explain why. To whet your appetite, yes, you can access a KiwiSDR across the Internet and record raw data from it and control the process externally. This is a very big chunk of the problem I've been working on and turns out to actually be live and ready to play with. Fair warning this is technical, there are moving parts. I'll do my best to explain, but if I miss any, feel free to get in touch, you have my address, [email protected]. In passing, recently I made mention of the KiwiSDR community and tools that could potentially allow access to a remote receiver, although at the time I pointed out that I wasn't sure if the tools I found could access remote receivers, or if they were intended to access hardware locally. KiwiSDR is one of a group of so-called Web SDR tools. Essentially a website where you can access a remote receiver and tune to the radio signals it can hear. SDR, or software defined radio, is a way to convert incoming antenna signals into the digital realm where computers, and in this case, the Internet, live. Turns out that a tool called "KiwiClient" takes a hostname and a port as a parameter, so much so that the in-built help shows this as the first example. What this means is that you can essentially run a copy of KiwiClient on your own computer and use it to access a KiwiSDR across the Internet. The first commit was on the 8th of May 2017 and thanks to the efforts of about 14 developers, KiwiClient is the software equivalent of a KiwiSDR multi-tool. This is exciting all by itself, but this gets better. You can specify more than one server. This means that you can record two, or more, signals from across the globe, and capture these simultaneously. You can set the decode mode, which I immediately used to tune to a local broadcast station and recorded it from two different receivers across the Internet, allowing me to not only compare the difference in delay between the signals, but also the reception differences. It's fascinating to hear the same station from two receivers, one in each ear, all manner of different propagation artefacts become apparent. Then I got a little more adventurous and discovered that one of the supported modes is I/Q, which means that I can, and did, download raw sample data across the network, which can then be used within GNU Radio. This is important because the aim for Bald Yak is to process the signals separately from the receiver. It gets better. There is a radio fax receiver that automatically saves pages as they are processed, something that you could use to access weather fax services. Then there's a tool you can link to "WSJT-X", which you might recall is an application that can decode weak signals. Not only that, the tool supports "fldigi", a digital radio mode application. Both those applications can control the radio using Hamlib rigctl, which means that KiwiClient supports changing frequencies of the receiver, across the Internet, though truth be told, I haven't yet tested that .. my available computing resources are still strictly limited. Oh, the software also has the ability to record waterfalls, do scanning, and provides tools to analyse waterfalls in jupyter notebooks. Getting this to work wasn't too hard. The instructions on the KiwiClient GitHub repository are pretty good. I've made an initial Dockerfile on my own GitHub repository to download and install the software. It's unimaginatively called "kiwiclient-on-docker". I've yet to discover a good way to add or update Dockerfile functionality to existing projects, feel free to make suggestions. Now I absolutely understand that this level of excitement might not universally translate and that's fine. It's yet another example of how rich and diverse our amateur radio community really is. What gets your excitement levels going? I'm Onno VK6FLAB

Foundations of Amateur Radio The other day I stumbled on a random post by Gary N8DMT which caused me to view the world in a different way. The post outlined combining a PlutoSDR and an application called SATSAGEN to measure the frequency characteristics of a coupler. Aside from a detailed description, the post includes a couple of excellent photos showing the PlutoSDR connected to the coupler and the output piped back into the Pluto. Before I continue, a PlutoSDR is a Software Defined Radio or SDR, officially it's called the ADALM Pluto Software Defined Radio Active Learning Module. It's essentially a full-duplex radio and computer in a box. It runs Linux and connects to the world via USB, and of course radio, unofficially between 70 MHz and 6 GHz. I've talked about this device before. When I say full-duplex, I mean that it can transmit and receive at the same time. Gary's post triggered something unexpected in me. The notion that you could use two patch leads, one connected to the transmitter, the other connected to the receiver, joined together by a device that you might want to test. It immediately reminded me of another device that was given to me, a NanoVNA, a device that's specifically designed to measure things like impedance, frequency response, generate Smith charts and all manner of other characteristics. Not only that, it also reminded me of another device, a TinySA, specifically designed to analyse spectrum and to generate signals. Both the NanoVNA and TinySA are lovely tools, but in looking at the post it suddenly occurred to me that their functionality, at least superficially, appears to mirror the PlutoSDR, in that you can create a signal and then measure that signal. Turns out that I'm not the first to make this observation. For example, the YouTube channel "From Concept To Circuit" goes through the process of describing precisely the concepts behind both a spectrum analyser and a network analyser while showing the programming code in Python. The channel also provides that code in a GitHub repository, which includes several other very interesting examples, like a beamforming transmitter as well as a beamforming receiver, also covered on YouTube. Another example is a tool I already mentioned, SATSAGEN, by Alberto IU1KVL, which implements a wideband spectrum analyser. Although it's Windows only, Alberto includes information on how to run it using Wine under Linux and MacOS. As a bonus, SATSAGEN in addition to the PlutoSDR, also supports RTL-SDR dongles, HackRF, USRP, RSP1, AirSpy, and many others. If text is more your thing, "retrogram-plutosdr", shows a spectrogram in your terminal window. Check out the "r4d10n" GitHub repository belonging to Rakesh VU3RGP, who says that the "retrogram" project is "hacked from" the "RX ASCII Art DFT" example, which you can find on the Ettus Research GitHub repository. One thing to consider is that the various GitHub repositories I've pointed at, will give you access to the moving parts of how all this works. I will mention that my favourite tool in this space continues to be GNU Radio, but I understand that you might not want to roll your own tool from parts. That said, rolling your own is in my experience a great way to discover precisely what you don't know and to come away learning more, but then, that's just me. Regardless of your chosen tool, I think the takeaway should be that when you try something new, even if it's only new to you, the idea of writing down what you discovered and sharing it, is a fantastic way to grow our community. Remember, just because something is old hat to you, doesn't mean that it is to the person you share it with. Besides, based on the current global birth rate, there's at least a thousand babies born during the past four minutes, some of whom will become radio amateurs, so, share. Said differently, if you come across a person who has never heard of the "Diet Coke and Mentos" thing, it's your job to immediately drag them to the nearest grocery store and introduce them. In case you're wondering, xkcd 1053. Now, I'm going to update the firmware on my PlutoSDR and have a play, I already know about the Mentos, but if you don't, you're in for a treat. What are you going to do next? I'm Onno VK6FLAB

Foundations of Amateur Radio Recently I discussed the idea of listening to the radio spectrum across the internet for the purposes of getting signal into your shack when radios, or in my case, antennas are causing you challenges. I continued to explore and discovered a project by Jacobo EA1ITI, called "radioreceiver". Behind that unassuming name lies a tool born in 2014, that allows you to plug an RTL-SDR dongle into your computer, open up your web-browser, and listen to the radio signals that your dongle can receive. In case you're unfamiliar, an RTL-SDR dongle is a small USB device, looks a lot like a USB thumb drive, jump drive, data stick or flash drive, basically a hunk of plastic with a USB connector on it. An RTL-SDR dongle generally also has some form of antenna connector. It's typically sold as a digital radio and digital television receiver, but websites like rtl-sdr.com sell purpose built ones. They can be found starting at about $15. I realise that this is using a local receiver, with a local antenna, but it's inside a web browser, which is half of what I expected. When you hit the play button in the bottom of the screen, you'll be prompted by your web browser to give permission to access your RTL-SDR dongle and the fun starts. You'll see a live waterfall, hear audio, and have the ability to tune to any frequency you can reach. Depending on your dongle, typically somewhere between 500 kHz and 1.76 GHz. The application consists of seven files, a total of 352 kilobytes that you can store on any web server and run, with one caveat, in order for your web browser to talk to your dongle, it needs to be served using HTTPS. Jacobo has set-up radio.ea1iti.es and I've set-up sdr.vk6flab.com, both showing the same tool. You'll find the code on my VK6FLAB GitHub repository, and of course on Jacobo's. There are some things you need to know. You will need to use a web browser that supports WebUSB, currently that's Chrome, Edge, Opera and several others, sorry, Safari and Firefox don't .. perhaps it's time to talk to Apple and Mozilla. All is explained if you click on the little question mark at the bottom of the screen, it will even tell you if the browser you're using to read the help is compatible or not. If you have an Android phone, you can run this tool too, although you will need to find a way to connect your dongle to your phone. I'm currently limited in my ability to test this and you may need to install some drivers on Windows and Linux, but MacOS and presumably Android, works out of the box. The software also supports offline operation, so you can load it as a Progressive Web App, or PWA, and use it in the field away from the internet. Did I mention that all the decoding is happening inside the web browser, so you can see which code is doing what .. and before you ask, yes, it's minimised in the browser, which you can make into human readable code, but when you look at the source, it shows precisely what is happening, all written in Node.js, TypeScript and JavaScript. It supports CW, SSB, AM, Narrow and Wideband FM and decodes stereo, something which none of my amateur radios do. You might be able to tell that I'm excited. It's because this is providing the basic functionality of a radio inside a web browser, and I didn't need to install it to get started. On the Macintosh I tested this on, I literally opened the web page, plugged in a dongle and hit play. Just so we're clear, just because this is using a web page on a web server, you accessing it will only give you access to your radio not mine. This of course opens the doors to all manner of other fun stuff which I'm expecting to play with for the next little while, and yes, this is also Bald Yak adjacent, I'm aware. In the meantime, you can play with this right now, sdr.vk6flab.com is the place to go. Word of warning, it's addictive and easy to forget it's a radio with an antenna plugged into your computer, so take precautions when electrical storms are about. Look forward to hearing what you discover. I'm Onno VK6FLAB

Foundations of Amateur Radio One of the many challenges associated with being a radio amateur is actually being able to listen to weak signals. If you're like me and more than half the planet, you live in an urban area, which comes with the benefits and pitfalls of having neighbours. From a radio perspective, there's plenty of noise that drowns out weak signals, so more and more amateurs are finding new and interesting ways to deal with this. Over the years I've talked plenty about so-called web-sdr, or internet accessible software defined radios. Essentially a radio receiver, preferably in a radio quiet area, hooked up to some software that allows you to listen in using a web browser. There's thousands of internet based services across the globe, the most popular of those are websdr.org and kiwisdr.com. As a new amateur you might have visited one or more of these and tuned around to listen to various radio stations and QSOs or contacts between amateurs, on bands that you can't access because you don't have the gear, or frequencies that are drowned out locally by your neighbour's pool pump, air conditioner, LED lighting, solar power inverter, television, motor home, cycle, or whatever else they seem to have an endless supply of behind closed doors. As a crusty amateur, and after about 15 years, I'm probably one of those, you might have started experimenting with building your own, or you might be blissfully unaware of these internet marvels. Either way, one restriction you run into is the ability to do anything other than listen. You might get the option to pick between Upper and Lower Side Band, or AM, sometimes even FM, but generally that's your lot. This means that trying to use such a tool to decode WSPR, or FT8, or RTTY, CW, PSK31, or whatever else takes your fancy becomes a challenge. It occurred to me that if you're able to capture the raw signal from a web browser, you could feed that into your decoder of choice. It would also mean that you wouldn't need any local hardware to start playing. Before you get all hot and bothered like I did. This is a non-trivial process that several others have attempted to wade through with varying levels of success. Much of the documentation I've discovered revolves around virtual audio cables and loop back software, and even the idea that you physically plug your computer's speaker output into your line input, or even hold a microphone up to your speakers. Aside from the lack of elegance associated with such contraptions, they require that you install all manner of weird software, and in many cases deal with permissions, since microphones are generally locked for good privacy reasons. Prompted by the webserial tool by Phil VK7JJ, it occurred to me that if we can talk to actual physical hardware within a web browser, then we can probably use a web browser as an audio source for local decoding software. Before you start hunting for the source code, there is none. I've spent the past few days playing around and although I made a waterfall display inside GNU Radio that used the audio from websdr.org, the results were not amazing, and I created a proof of concept by using a tool called BlackHole on the Macintosh I was using at the time. It's essentially doing shenanigans with audio mapping, not something which I really want to do, but it gives me a pretty picture, or not, as the case may be. More interesting is the progress being made over in the KiwiSDR community, where there is already an I/Q button, in other words, the raw data needed for processing further down the line. I came across projects that link the KiwiSDR to other tools, but it's unclear if that's the hardware, or the web client, I suspect it's the hardware, but I might be mistaken. If you're not sure what this might mean, think about listening to the same frequency at the same time across the globe using multiple web browser tabs, and comparing the signals in real time, or decoding them, or using them for comparing signal strengths, or propagation, or any number of things that are currently only possible with a vast network of radios under your own control. If you need to nerd out on the technicalities, the idea is that if you can access an SDR via a web browser, it would be cool if we could decode the stream coming back without needing to install software on the computer. There appear to be tools that do this kind of thing to get the audio into "ffmpeg". If that's gobbledegook to you, ffmpeg is a tool that allows you to do all kinds of cool stuff with audio and video. Using something called WASM, or webassembly, it's possible to link web browser audio to ffmpeg. I suspect it's possible to use the same mechanism to send audio to GNU Radio, or any other decoder, for processing. There also appears to be a thing called a Web Audio API AudioBuffer where the raw audio gets sent to, so perhaps that's accessible in some way. The point being, that I think this is doable, so much so, that I suspect that someone alr

Foundations of Amateur Radio Every single radio amateur has come to this hobby with an itch to scratch. Time and again I've seen amateurs around me pursue that particular purpose, only to come out the other end with a look of bewilderment writ large across their face. For some amateurs it means the end of their involvement in the hobby, for others it starts a new journey into the unknown. One of the ways we explore our community is by travelling out of our shack into the big outdoors in whatever form that takes. Popular activities include setting up a radio in a location and talking to others, known colloquially as an "activation". We do this all over the planet. Perhaps the most recognisable of these is IOTA, or Islands On The Air, where a station is erected on an island and contacts are made. As amateurs we cannot help ourselves and seem to have an insatiable need to measure our prowess. We do this by counting how many contacts, callsigns, countries, grid-squares, or in this case, islands, we've managed to put in the log. If an island represents a new callsign, a new country, and a new grid-square, the contact making will turn into a feeding frenzy that can last for days, especially if the station offers multiple bands and modes, making the effort all the more tempting. We don't stop with islands. Summits, with Summits On The Air or SOTA are popular, as are Parks, POTA, and even over a weekend, the International Lighthouse and Lightship Weekend, or ILLW. Some of these activations follow rules set out by amateurs like you and I, who thought it would be fun to track such activations and encourage others to participate. For example IOTA World publishes a four page document outlining what's required for those on the island, activators, and those trying to make contact, or chasers. This raises an important point. Rules require documentation, which leads to discussion and disagreement, and versions. I can show you two versions of the IOTA World rules, neither is dated, of course both are different, so if you're going to publish rules, make sure you add a date or version, preferably both, to the rules document. Disagreements aside, sometimes there are multiple programs with the same name or aims. Two groups came up with the same idea and didn't know about each other, or, a group in a different country wanted to run the show in a different way and a new group was formed. I'm mentioning this because sometimes these groups are antagonistic towards each other and have forgotten that the whole point of this is to have fun. So, what else can we activate? Well, there's Castles and Stately Homes, Bunkers, Beaches, Museums, Walmart Parking Lots and even Toilets On The Air, mind you, Slow Scan Television, or SSTV is discouraged as a mode. The other day the power was off for maintenance in my street and I planned on escaping to the local library, which caused me to search for libraries across Perth. It seems there's pretty much one in every suburb and I considered the notion of activating a library or three, comes with easy access to public transport, a car park, and even toilet facilities, what's not to like? I wondered what might be a suitable exchange so it could incorporate the library itself, promoting amateur radio and libraries, two birds and all. I made a comment on mastodon.radio and it turns out that Frank K4FMH beat me to it, several years ago. Libraries On The Air, or LiOTA. I've been hunting for a dataset of libraries in Australia to give to Frank, but it's been slim pickings, despite there being over 10,000 of them, apparently around 10% of those public. It raises another question, is there a directory of activation types anywhere? I couldn't find one, so I started a list on my GitHub repository. Feel free to add any I missed. Toilet jokes aside, consider that TOTA is being held during the annual Hackers On Planet Earth conference and it will introduce new people to our amateur community, which ultimately might be the best reason to have fun, get on-air and make noise. I'm Onno VK6FLAB

Foundations of Amateur Radio Recently I came across a series of strident posts about the injustice associated with a non-amateur service using the 70cm band. Complete with links to discussions, spectrum plots, angst and even incoherent outrage, all related to the notion that whomever "allowed" this user to transmit on this band was clearly incompetent. Except, that this is probably not the case, or the full story. So, what's going on and why are people incensed? This all started at least six years ago. Since then AST SpaceMobile has deployed seven low Earth orbit satellites and used the 70cm band to communicate with them. Although in the trial phase, there's plans for an additional 243 satellites, and there's at least one other company playing in the same space, Atmos Space Cargo. The outcry from amateurs is around the commercial use of "their" 70cm amateur band. It's an emotional statement, but what is the reality? Before I dig in, let's set some terms. Radio frequencies are globally coordinated because electromagnetism doesn't care about sovereign borders. This coordination is conducted at the United Nations by a body called the ITU, the International Telecommunications Union. Within that body, amateur radio gets a seat at the table from an organisation called the IARU, the International Amateur Radio Union. For the purposes of the ITU, the world is divided into three, Region 1, or essentially Europe, Russia and Africa, Region 2, the Americas and Greenland, and Region 3, the rest of the world. There's more to it, for example, Antarctica is split across all three, but for the moment, that really doesn't matter. Of interest is that the band plan, the agreements that outline which frequencies are set aside for what service, might be defined differently across each of those three regions. To add complexity, each country can be granted exceptions. I don't know the exact mechanics of how this is achieved, but I can guarantee that there's lots of haggling and foot stomping, diplomatically of course. If you're curious how I come to that observation, just look at the absurd list of exceptions associated with each band plan allocation. Further complexity is added by the fact that not all allocations occupy the same frequency range. For example, in Region 1, the 2m band for Amateurs exists between 144 and 146 MHz, in Region 2 and 3 it's between 144 and 148 MHz. Within an allocation there is the concept of shared and exclusive priorities. These determine who "wins" if two stations with a different service are transmitting on the same frequency. Essentially, a secondary user may not interfere with a primary user and a tertiary user may not interfere with either a secondary or a primary user and so on. A primary user can pretty much do what they want, as long as they stay within the allocation and don't interfere with other primary users. As a result, the order in which services are listed, matters. An exclusive allocation doesn't have to be shared at all. Between regions these service priorities might not be the same. For example, in Region 1 between 430 and 432 MHz is allocated to Amateurs and Radio Location, but in Region 2 and 3 it's between Radio Location and Amateurs. So an amateur using that frequency whilst in Region 1 would be a primary user, but in Region 2 or 3 they wouldn't. As an added wrinkle, for example in Australia, that slice is "primarily for the purposes of defence and national security", even though Radio Location is the primary service and Amateurs the secondary one. As a bonus, amateurs in Australia have access to 420.8 to 421.2 MHz as a secondary service, even though the ITU designates this as Fixed, then Mobile, except Aeronautical Mobile, and then Radio Location. Although amateurs are a secondary service, they come after the Department of Defence who are the primary users for those frequencies in Australia. Between 420 and 430 MHz, and from 440 to 450 MHz in several countries, Australia included, the Amateur Service is explicitly designated as a secondary service even though the band plan doesn't actually show this. If you're confused, you're in good company, since this tapestry of regulation isn't as straightforward as the "70cm band is an amateur band", in fact, I'd go so far as to say that it's not an amateur band at all, except perhaps in Region 1 between 430 and 440 MHz where Amateur is designated as the non-exclusive primary service. Back to the blow up. AST was at one time authorised to use 430 to 440 MHz for trial purposes by a regulator in Region 2, the FCC, the United States Federal Communications Commission. I suspect that at the time, the Blue Walker 1 nano satellite was experimental and the approval made sense. You can argue that whomever initially allowed this made a mistake, but, reality is whatever the regulator says it is, unless someone at the ITU objects. It appears that the FCC has since been attempting to make AST comply, instead with billions of dollars at stake, AST cont

Foundations of Amateur Radio In the community of radio amateurs scattered around the planet we have a habit of getting together with others to have fun in whatever shape that takes. The obvious ones are HAMfests, car boot sales, raffles and other amateur adjacent pursuits, but we also do things like licence training, weekly on-air nets, contesting, portable activations, climbing mountains, or hills, setting-up in parks, or lighthouses, we set-up on a field day, just for fun, and find excuses, sorry, reasons, for any number of other activities. Some of these are solitary affairs, but many are best enjoyed shared with multiple friends, both old and new ones. Having been a member of this community since 2010 I've come to observe an aspect of this community that is odd, to say the least. We organise all these events, but rarely promote it beyond a single email to three people, if that. It's almost as-if the average organiser thinks that their event permeates the community by magic osmosis. Even if there is any form of promotion, there's sometimes a date and time, but hardly ever does it show that time in UTC, even if it's a radio event, it's like we've forgotten that radio waves pass through time zones, or there is a misconception that everyone on the planet knows what your local timezone is, let alone if it's summer or winter time at the time of the event. So, what does promoting your event look like if you actually want people to know about it? For starters, you should consider who you want to have as a participant. A local HAMfest is unlikely to attract people from around the globe, but Friedrichshafen and Dayton are examples that contradict that notion. A VHF-only event might be intended for local amateurs, but what if it allows for satellite or digital contacts, like say via Allstar, IRLP or Echolink? Similarly, you might run a weekly on-air net, but have visitors from around the planet. The point being, that your audience might not be exactly what you initially think. In other words, there might be people playing from further afield. Consider that when you announce what time the event starts, and finishes. Speaking of finishing, adding an expected closing time is helpful for participants where only one member of the family lives and breathes amateur radio and the rest just want to get on with their respective lives, so consideration is welcome. Aside from telling your audience when and for how long the event goes, adding a location is not optional. You'd be surprised how many events say things like: "it's again in the usual location", or "we're at the community hall" without ever publishing an address. I can tell you, it's fun discovering that the name of the hall isn't unique. Now, for the big one. After putting the information together about the event itself, where and how do you announce it? For starters, on your own website, in whatever form that takes. It serves two purposes, announcing to the world what is happening, but it's also the definitive place where the right information is published. This is important because things change, get cancelled, moved, updated, whatever. Life isn't static, so you need to define a place where the official announcement lives. At this point I'd like to mention that this is often where promotion stops. It's easy to think that in your universe everyone you know is aware of your website, but that's just not true. A single place to publish is not the end of the process, it's the start. Then you need to use things like the local news broadcast, the national news broadcast, the international news broadcasts, contesting websites and calendars, social media, fediverse and whatever else you can get your hands on. You need to include it in your own club news, in club newsletters from other clubs, on the local amateur notice board, you need to talk about the event on-air, share it during on-air nets and if it's recurring, tell the world that it's going to happen again next year. Nothing here is revolutionary, it's not like launching a rocket into space, this is basic common sense and you too can do this. If you need help, ask. So, if you have an event that you want to have participants for, you need to make noise. Publishing the announcement at the local planning department in Alpha Centauri 50 years before the event is going to cause issues, as will defining the date for an annual event as: When the June solstice is on a weekday (Monday through Friday), the weekend following shall be the weekend of the event. When the June solstice falls on a Saturday or Sunday, that weekend shall be the weekend of the event, but only for the Winter field day, the Summer one requires you to count back four weekends, or forward, depending on if you're talking about the Spring or Summer event, and add one if it falls on the weekend. In case you're wondering. No, I didn't make that up. It's real. I'll leave you to ponder how you'd add such an event to your family calendar. I'm Onno VK6FLAB

Foundations of Amateur Radio Recently I was given some radio data captured on the 40m band. Using a piece of software called "Universal Radio Hacker", I attempted to decode it. At the time I thought that this might be Morse code, since then I've been told by someone who has been using Morse longer than I've been alive, that it isn't. I shared the data on my VK6FLAB GitHub repository where you can download it and see what you learn, and perhaps repeat what I did, or better still, improve on it. Over the years I've talked a little about how Software Defined Radio or SDR works, essentially it's a glorified Analogue to Digital converter, much like the sound card in your computer, which does the same, albeit at a much lower frequency. As it happens, you can represent the signal that comes into your radio antenna as a series of values. Essentially, the stronger the signal, the bigger the number, the weaker the signal, the lower the number. Let's talk about the characteristics of this signal. It consists of two parallel signals, in opposition to each other. The first signal jumps intermittently between 7 kHz and 40 kHz, where the second jumps between -7 kHz and -40 kHz. The recording is marked 7.06 MHz, so if we think of that as the central frequency, the whole signal sits between 7.02 and 7.1 MHz. This 80 kHz wide signal is not something you'd typically be able to hear using a standard amateur radio receiver which tops out at about 3 kHz bandwidth. It's so wide that you couldn't even hear more than one of the four tones at the same time. Randall VK6WR, who supplied the recording, spotted it on a waterfall display showing a chunk of radio spectrum, in fact, a $25 RTL-SDR dongle could receive this signal. Aside from the fact that this is a really wide signal, well at least in traditional amateur radio terms, it was interesting in that it was heard on the 40m band. As it happens, just after I shared my initial exploration, I was told by several other amateurs that they had heard the signal. I even saw it on a WebSDR in India and attempted to record it, but failed. As it happens, a few weeks ago, I was playing with something called "CAN Bus", or Controller Area Network, a technology that was designed in 1983 and is used all over cars for things like sensors for speed, engine temperature, oxygen level, detonation timing and anything else that's happening inside a car. You might know the end-user view of this called OBD2 or On Board Diagnostics, second generation. I was looking into it because my car has been acting up and I've been trying to track down the root cause. Anyway, I learned that CAN Bus is implemented using something neat, "differential signalling", where two wires each carry the same, but opposite signal, so they can be combined to ensure that in an electrically noisy environment like a car, the information still gets where it needs to go. Seeing the radio signal Randall shared, reminded me of this. Noise immunity is a useful attribute in digital HF communication, so I can understand why it was done like this, but it also means that either signal was sufficient to start to decode the information. We can use Universal Radio Hacker to show us only half the signal using a band pass filter. I then decided that the 40 kHz frequency was "on" and represented by a "one" and the 7 kHz frequency was "off", represented by a "zero". Of course that's entirely arbitrary, there's no reason that it cannot be the other way around, but for our purposes it doesn't matter at this time. That said, we don't yet have enough to decode the actual signal. We need to figure out how long each switch, or bit, lasts, because two zero's side-by-side or two ones side-by-side would look like a long "off" or a long "on". Using that logic, you could also say that the shortest possible duration for a 40 kHz or a 7 kHz tone would represent a single "one" or a single "zero". Of course, this is a simplified view of the world. For example, the data file contains more than thirteen and a half million bytes. Half of those are for the I in I/Q, the other for the Q. I'm purposefully glossing over a bunch of stuff here, specifically the notion of so-called I/Q signals, that's for another time. In computing a single byte can represent 256 different values. It means that if the signal is represented by a single byte, a voltage from the antenna at maximum amplitude can be represented as 255 and the minimum amplitude as 0. As it happens, voltages go up and down around zero, so, now we're only using half a byte, 127 for maximum, -128 for minimum. If we use two bytes, we get significantly more resolution, -32,768 as the minimum and 32,767 as the max. A little trial and error using another tool, "inspectrum", told me that the data was organised as two bytes per sample. Which brings the next point. How many samples per signal? Said differently, we're measuring the antenna voltage several times per second, let's say twice per second. If a tone of 7 kHz lasts

Foundations of Amateur Radio Recently I was helping a friend erect their newly refurbished multi-band antenna and during the process we discussed the notion of tuning an antenna that's high in the air. They made a curious response, in that they'd tuned the antenna on the ground before we started. I asked how this would work, since as I understand the process, this changes things once it gets in the air. They assured me that while the actual SWR might change, the frequencies at which it was resonant would not. This was news to me because I've been putting off erecting my own multi-band 6BTV antenna mainly because I didn't really want to face having to erect it, tune it, lower it, modify the elements, erect it, tune it, etc., all whilst standing on the steel roof of my patio. Would this phenomenon be true for my antenna? It occurred to me that I could test this idea, not only for my antenna, but for other antennas as well. In my minds-eye, I saw a video displaying the pertinent attributes of an antenna, SWR, gain, radiation pattern, and whatever else I could think of, animated with the modifications of things like height and ground radials. If this sounds familiar in some way, it's because I've been here before. This time the outcome was slightly different, since I found a tool that can optimise antennas using a genetic algorithm. What I mean by that is an automated process where you can test variations of a thing, in this case antennas. Rather than design each antenna and test it, you essentially generate antenna designs and tweak them to determine the best one. Then you use that to generate the next series of designs. Rinse and repeat until you have what you're looking for. There's a whole field of computer science dedicated to this and unsurprisingly the rabbit hole goes deep. The tool is called "xnec2c-gao" and it's written by Maurizio DC1MDP. The name of the tool hints at its nature, working in combination with "xnec2c", written by Neoklis 5B4AZ and maintained by Eric KJ7LNW, you'll find links to both tools on the xnec2c.org website. How the two tools work together is a beautiful dance. The antenna modelling tool, xnec2c, can read an antenna definition file and detect if it changes, at which point it can redo the simulation, which it can output to another file. The genetic algorithm optimisation tool, xnec2c-gao, can detect the changed output and update the antenna definition file, and the process repeats. Which brings me to a pro-tip, for this to work, you need to configure xnec2c to do two things, detect the changed definition file, and write the output to CSV, both of these options can be found in the "Optimization Settings" menu, just so you don't spend an hour banging your head against the desk. Between the two tools, the antenna definition evolves and you end up with a design optimised for your purpose. The default does this for SWR and gain. Mind you, I tested a multi-band dipole which managed to find some interesting designs, but didn't pick them because a low SWR combined with a high gain, for reason't I don't yet understand, wasn't considered better than a high SWR with a high gain, so there's some work to be done. As a software developer I have a sneaking suspicion that it's adding the two, rather than picking the highest gain combined with the lowest SWR, but I haven't confirmed that. As I said, deep rabbit hole. While we're not yet at the video display stage, for the first time I can get a sense that this might come to pass. There's plenty of work to be done. For example, the antenna display on xnec2c during the process seems broken, there's no way to output gnuplot files during the process, and capturing the various charts in real-time will require work, but all that seems if not easy, at least possible. Meanwhile, I'm attempting to locate an antenna definition file, preferably in .NEC format for my 6BTV antenna, so I can use this combination of tools to discover if tuning it on the ground will work and while I'm at it, discover if the installation I'm working on will give me something worthwhile. I realise that this is well beyond "try it and see", but my body isn't up to climbing up and down ladders 17 times in a day and I think that getting a feel for what might occur is a good way to learn. When was the last time you climbed on a roof and what did you do to avoid it? I'm Onno VK6FLAB

Foundations of Amateur Radio Just over a year ago, the ARRL, the American Radio Relay League, the peak body for amateur radio in the United States and one of the oldest of such organisations, experienced an incident. During the weeks following, the ARRL was tight-lipped about the extent of the incident and most amateurs only really noticed that services were off-line or slow to respond. After months of delay and disinformation, the ARRL finally revealed that it was the subject of a ransomware attack and that it had paid a million dollar ransom. It went on to blame the authorities for its silence. Mind you, it didn't tell me personally, it made public statements on its website. Similarly when I specifically contacted the ARRL to discover what information of mine it held, and what the status of that information was, the ARRL responded that I should refer to its public statements. It continued to state that my information was not compromised, since it only lived in LoTW, the Logbook of The World, the system it uses to coordinate the verification of amateur radio contacts, which are used to distribute awards like the DXCC and Worked All whatever. Imagine my surprise when I received an email this week, sent from "[email protected]" to my non-amateur radio email address. I confirmed with several amateurs that they too received this email. Informative, to a point, but likely well beyond anything intended by its author, it stated that LoTW was being updated with associated down time, incidentally, inexplicably, coinciding with the 2025 ARRL Field day, and it "will be fully migrated to the cloud". It went on to solicit donations. It made no reference whatsoever to the ransomware attack. There's a lot hidden in that email. Although the attack last year was linked to the outage associated with LoTW, the ARRL has continued to claim that the LoTW data was not impacted by the ransomware attack, but the email reveals that the system is being migrated to the cloud, in other words, right now, it's not in the cloud. Which begs the question, where is the server infrastructure for LoTW today, and more importantly, where was it a year ago when its systems were compromised? From a public post by Dave AA6YQ, dated the 2nd of February 2021, in response to a message about a January LoTW committee meeting, we know that the LoTW server "now employs the current version of an SAP database engine". A month before that, Dave wrote another informative email that indicated that 105 thousand callsigns submitted logs to LoTW in the last 1,826 days or the five years between 2016 and 2021. There were logs from 21 thousand callsigns in the week prior to that January post. In all, according to Dave, there were 153,246 callsigns who submitted contacts to LoTW. The LoTW committee meeting minutes are no longer available from the ARRL website, but I have a copy. The document states that there were 1.2 billion contacts entered into LoTW, big number right? The next line tells us that this resulted in 262 million QSO records. I wonder what happened to the other billion records? This activity was generated by 139 thousand users using 200 thousand certificates. For context, every VK callsign automatically comes with an AX callsign, but LoTW requires that you separately register each with its own certificate. As someone who has been playing with databases since the 1980's I can tell you that LoTW is a tiny database. For comparison, the WSPR database is an order of magnitude larger, not to mention, more active. I have no insight into the business rules within the LoTW database, but the fact that updates are being processed in batches and that it regularly has delays indicates a level of complexity that I cannot account for. As an aside, the LoTW committee document lists 10 members. Dave is not one of those listed. It makes me wonder who else has access to this database. Note that I have no reason to believe that Dave's information is questionable, nor that he has access that he shouldn't, he was after all a member of the LoTW committee from 2013 until 2017 when the ARRL removed all development resources from the LoTW. I'm asking who else has access and why? While we're here, who has been doing maintenance and updates on this system over the past seven years? Moving on. The database for LoTW contains information from amateurs all over the planet, including those in Europe where the GDPR, the General Data Protection Regulation, enacted in 2016, is extremely strict on the security and disclosure of personal data with very heavy penalties for breaches. The GDPR requires notifications be sent within 72 hours of a breach, and that an organisation must designate a data protection officer. I wonder who has that role at the ARRL and I wonder if they told anyone? Did any European amateurs receive personal notification from the ARRL about their data, I know I didn't. My first activation of LoTW was in 2013, now twelve years ago. I received certificate expiry messag

Foundations of Amateur Radio The other day Randall, VK6WR, encouraged me to get on-air. He described it like this: "There is a mystery signal on 40m that you can try your new Universal Radio Hacker skills on. It appears to be a FSK signal separated by 7kHz with the two signals at 7.0615 and 7.0685 MHz. Each of them on their own sounds a bit like a Morse signal, but my CW decoder decodes junk. But if you can see it on a spectrum scope, it is clearly FSK because either one of them is on at any time." He went on to say: "You'll need an SDR to receive the signal given the separation, but could be a fun investigation!" Having just discovered "Universal Radio Hacker", a tool that can help you decode radio signals, that sounded like something I'd love to have a go at. Unfortunately, after the demise of my main workstation last year, my current set-up doesn't allow me to do such recordings, but Randall, ever the gentleman, provided a recording of the signal. He writes: "This was captured with gqrx demodulating the signal as SSB audio with the VFO tuned to 7.060, so both "signals" are there, one very low freq and one very high freq." If you're curious, I've uploaded the file as it was shared with me to my VK6FLAB GitHub repository under "signals". Over the next two days I spent my time attempting to decode this signal. I opened up Universal Radio Hacker and spent delightful hours getting precisely .. nowhere. Some of that is absolutely my unfamiliarity with the tool, but this is a great exercise in learning on the fly, where truth be told, I tend to live most of my life. It wasn't until several hours later that I decided I should at least listen to the audio. To my ear it sounded like 25 WPM Morse Code, but being still in the learning phases, while my brain was triggering on the sequences, decoding wasn't happening. Of course I could cheat and forward the audio to one of my fellow amateurs, but the actual message wasn't really the point of the exercise, at least not at this stage. Instead I fired up "multimon-ng" which has an in-built Morse decoder. I spent some hours doing more Yak Shaving than I was expecting, but even then, I still didn't get more than gobbledegook out of the process. I used "Audacity" to shift one of the signals by one wavelength and mixed them together. This allowed me to reduce the noise significantly, but still none of my tools did anything useful. In case you're wondering why, if you have a tone and noise and shift one signal by the wavelength of the tone, then mix them, the tone adds to itself, but the noise, random in nature, is just as likely to add as it is to subtract, so in effect, you're increased the signal to noise ratio. After multimon-ng failed, I tried an online Morse decoder, which gave me all manner of text, but none of it made sense to me. Of course it's possible that this is someone rag chewing in a different language, but I couldn't make any sense of the thing. I did come up with some issues that prompted me to create the signal repository. I realised that I didn't have any known "good" signals. Previously I'd tried decoding a sample FT4 signal, but that went nowhere, mainly because the signal was noisy. So, what I'm going to do over the next couple of weeks is create some clean, as-in, computer generated, known signals, and add them to the repository. The aim is to have a known good starting point to learn from. In software development this technique is often used to limit the number of unconstrained variables. In our case, if I generate a known good Morse Code signal, then I can learn how to use Universal Radio Hacker to decode it, so when I come across an unknown signal, I can use the techniques I learnt to attempt to decode it. Feel free to make pull requests with known good signals yourself. RTTY, PSK31, WSPR, FT8, etc. Feel free to include non-amateur modes. One thing, I'm not looking for off-air recordings of signals, yet, that can come later, right now I need signals that are pure, as-in, as I said, computer generated. Of course at some point, perhaps sooner rather than later, I'll discover that generated signals are no easier to decode than off-air recordings, but that's for another day. Meanwhile, you too can play. Download one or more sample files and decode them. Let me know what you learn. I'm Onno VK6FLAB

Foundations of Amateur Radio The other day I was discussing with a fellow amateur the increased frustration my mobile phone provider was inflicting. We hit on the idea of figuring out if other providers would fit the bill and how we could determine if their coverage would suit our needs. Aside from using an old mobile phone, I suggested that using a $25 RTL-SDR dongle would provide a way to record mobile phone cell site beacons from the various mobile networks to map what signal levels we might find. To that end, I discovered a tool called LTE-Cell-Scanner by Xianjun BH1RXH. Forked from the original project by James Peroulas, it allows you to use simple hardware to scan for LTE Cells used by mobile phone networks. James points out on his site that this tool can also be used to calibrate an RTL-SDR receiver's oscillator, since an LTE downlink centre frequency is stable to within 50 Parts Per Billion, that's 10 times more stable than my Yaesu FT-857d using a TCXO. If this doesn't mean much, think of it as a local frequency reference standard that you can use in your shack with minimal effort and cost. The story gets better. I started building LTE-Cell-Scanner from source and in doing so discovered a directory on my computer named "uhrr". I didn't remember what it was for, so I looked online. The first search result, when I looked for "uhrr radio" was a repository by Oliver F4HTB, more on that in a bit. The second search result was something called "Universal Radio Hacker". I clicked on the link and discovered a mind boggling tool. There are times in your life when something flips, this was one of those times. It happened when I discovered "csdr" by Andras HA7ILM and again when I discovered "GNU Radio". Diving into "Universal Radio Hacker", by Dr. Johannes Pohl and Dr. Andreas Noack I was introduced to the art of decoding and generating digital radio signals. In 2018 it was presented for the first time during the USENIX Workshop on Offensive Technologies, or WOOT, as a tool to discover, decode and identify exploits of proprietary IoT devices scattered all over the planet. As an aside, USENIX, Users Of Unix, since 1975. Back to radio. Universal Radio Hacker allows you to dissect recorded radio signals using all manner of interactive processes. When you go looking for it, and you should, I recommend that you start by watching some videos. You'll find an introductory play list on my YouTube channel. By the time you've seen those, you'll likely share my excitement. To encourage you further, the Universal Radio Hacker is open source, written in Python, and runs on Linux, MacOS and Windows. So far there have been 94 releases of the software, so it's seen significant development in the years since it was released into the wild. When installing it I was surprised to discover that its acronym was "uhr", not "uhrr". This was a relief since I still didn't remember what "uhrr" was all about and I couldn't imagine having forgotten Universal Radio Hacker. It turns out that the last time I looked at "uhrr" was apparently in 2021 when I shared my experience in an article titled "The remote edge..."; "uhrr" or "Universal Ham Radio Remote" is a tool that allows you to use a web browser to access a radio remotely. My little journey into unexpected diversions, distractions and discovery has led me into a path where several puzzle pieces have come together. For example, Universal Radio Hacker and GNU Radio can talk to each other, they're both written in Python, they're both open source, have a history of development and have a community of users. The LTE-Cell-Scanner, also open source, will allow me to calibrate most if not all of my radio gear and I'm once again inspired to keep digging into yet another aspect of this wonderful hobby. I'm sure that there are more than a thousand different hobbies under this roof. Go forth, explore, discover, be amazed, and stay curious! I'm Onno VK6FLAB

Foundations of Amateur Radio The other day a fellow amateur asked me to help them with lowering their radio mast so they could do some maintenance on the antennas attached to it. This is not the first time I've been a participant in such an activity, but it was the first time I felt explicitly safe. Don't get me wrong, on previous occasions nothing bad happened, but there was always an undertone of "what-if" and an associated anxiety. This time was different. Before we did anything, we sat down, had a cup of coffee, talked and discussed what was going to happen. After coffee we looked at specifics and discussed the process in detail. Then we prepared. Clipping cable ties, winding up loose ends, disconnecting coax, and securing a pulley to a tree. We ran a winch line, discussed distances, looked at potential snags and coax lengths and angles, considered what would happen if something unexpected might happen and discussed various safety considerations, like never walking below the mast whilst it was in its most stressed position, half-way lowered and out of reach. Then we slowly went about doing what we talked about. All that sounds pretty reasonable, and it should. It was the first time I'd ever discussed in detail what the plan was, what could happen if something broke, if something got caught and any number of contingencies. We even discussed handling steel winch lines, something which I was unfamiliar with. Of course it's entirely possible that something bad could happen, something neither of us had considered, but we put ourselves in a position where we both felt safe after mitigating known risks and allowing leeway for unknown risks. Another word for this type of preparation is "Professionalism". It's a fraught word. You might recall me telling a story where I contacted the regulator to discuss wideband interference caused by a train-line, specifically blocking out a range of AM broadcast frequencies, including the emergency broadcast station. I revealed during that conversation that I was an amateur and had some experience with radio. The person I was speaking to shared that they were a "Professional", using a capital "P" to condescend that my amateur credentials were nothing in comparison to theirs. The conversation ended, the wideband interference is still there, years later. It's not the only time I've come across this weird relationship with this word "Professionalism". At one time I worked at a community broadcaster where I was one of the producers and presenters. If you're unfamiliar, it's essentially a special interest broadcaster, in this case radio, run by mostly volunteers. We were having a meeting to discuss plans and during that I raised the notion of "Professionalism" in relation to conduct, things like turning up on time for your shift, documenting labels correctly on tapes, keeping logs, broadcasting advertisements at the allocated time, etc. Unfortunately some in the group equated "Professionalism" with "Commercialism" and expressed their discontent with the notion vocally. I stopped volunteering there shortly after. This to say that I can understand that "Professionalism" has different meanings for different people. In a community like Amateur Radio it might mean that it's considered a taboo word, but I'd like to encourage you to think of it as a way of getting things done .. safely .. and to the betterment of the community. So, next time you have a working bee, an antenna party, a contest, or a ham-fest, think about how you conduct yourself, how you might improve the experience for yourself and for those around you. I call that "Professionalism". I'm Onno VK6FLAB

Foundations of Amateur Radio The other day a report in "Amateur Radio Daily" caught my eye. Under the heading "IARU Considers Consolidation", I read that the International Amateur Radio Union, celebrating 100 years of representing our hobby, is considering significant change. Links in the report reveal a PDF document titled "IARU Consultation on Proposed Restructuring March 2025". The document, dated 21 March, outlines the structure of the IARU, four organisations, one for each ITU Region, and one global organisation, the International Secretariat. It provides some insights on how the funding arrangements between these organisations exist and goes on to talk about how the IARU operates, including incorporation, or not, currencies, committees, priorities and other background and historic information. All excellent. Stuff that should be public knowledge, but having spent the better part of a year reading IARU documents, this one brought several new eye opening things to the table. The document attributes no authors but is at least spell-checked in US English, and appears to be part of a discussion started long before I became an amateur. In 2005, the IARU started the "IARU 2025 Committee" to look into the future of the organisation. It concluded its work in 2012. In 2020 a new committee was started, the "Future Committee", consisting of representation from each of the regions. The introductory wording is curious and includes these words: "We can no longer afford not to move the process forward" - at least implying that this document is a foregone conclusion. Searching for the document on the IARU sites will give you no results. Searching for "Future Committee", gives you two results, neither actually having the words "Future Committee". The only reference which makes any sense in either of those two results, and only after the fact, is a paragraph, published on 12 October 2020, that refers to the Administrative Council, or AC, and states: "The AC received and discussed an in-depth report from its Working Group on the Future of IARU and agreed to steps for evolving toward a more flexible organization and strengthened relationships with all stakeholders in the global amateur radio community and telecommunications ecosystem." For a process that started 20 years ago, this is the first I've heard of it. Curious wouldn't you say, in an organisation that claims to represent both you and I? It's almost like the IARU wants to keep this whole thing a secret. There's more. The thrust of the document is to explore the notion of simplifying the operation of the IARU by consolidating the four organisations into one incorporated body based in Switzerland, where the IARU Region 1 organisation is currently incorporated. It goes on to discuss how this is great for the hobby, how it will save on resources and how it will allow the mostly volunteer run organisation to operate more democratically. It outlines the process for adoption, including a 60 day consultation period for the 167 Member Societies, as-in peak bodies in your country. I'll save you the suspense, the consultation period ended before I saw the document. There's a 30 day "Detailed Draft Proposal phase" and a "Final Proposal and Voting stage", neither of which are on any specific time-line that I could find. You might say, well, Onno, you're not a member society, it's none of your business. That's true. Here's the thing. Let me quote from Section 5, on page 11: "In many cases the IARU Member-Society does not represent the majority of the national amateur community." So .. not to belabour the point, the IARU, who is proud to represent Amateur Radio on the International Stage, writes in its own documentation that the organisation doesn't represent the majority of amateurs while claiming its intention to make the organisation more flexible and democratic. Gotta say, feeling all warm and fuzzy. In Section 6, the document goes into great detail about finance. I'm kidding, it has one sub-sub section about money, section 6.1.3, less than 10% of the document, no less explosive for its brevity. It states that each region contributes to the overall IARU budget, but that this contribution remains insufficient to cover the many critical representation efforts required. It goes on to say that "Historically, the ARRL has played a key role in bridging this financial gap". For its contribution, the ARRL currently nominates the President and Vice President which the member societies get to vote on. I wonder what happens if they don't vote for the nominated candidate and what happens when the ARRL is no longer first among equals, will it continue to fund the IARU? While pointing out that all direct representation of the IARU at the ITU are made by volunteers, as well as "nearly all" other activities, I wonder which activities are paid and how much? There's also discussion about a "not ideal" "compromise", namely that we'll have to be virtual attendees to save money. Really? In 2025,

Foundations of Amateur Radio Right off the bat, let me start with a question. "What do you think you're doing?" To give you some context, it should come as no surprise that I'm talking about amateur radio and what it is that we do, you and I, when we "do amateur radio". Of course the answer is different for every person you ask, and it's likely to change over time. So, let's explore and fair warning, if you know me at all, you'll realise that I'll be asking more questions, so here goes. Is this an activity that you do, for yourself, or for others? Is it a hobby, or a vocation, or something else? Do you use this as part of your life outside this community and if you do, how? At this point I hope you're getting a sense of Deja-Vu all over again, in that I'm asking you to explore your own place in the community. I'm asking because it occurs to me that we spend an awful lot of time looking in the other direction. How do we compare skills and knowledge against other amateurs, how does our shack compare with another, how does our antenna stack up, which modes have you used, what things have you activated, how much power do you use? All things that might form part of the activity of amateur radio, but fail to look at you as a person and your role in this. For example, have you considered if you're interested in helping new amateurs, or would you rather just do your own thing? What about how you gain skills? Would you rather read a book, watch a YouTube video, attend a class or play with others? If you're considering upgrading your license to gain more responsibilities, are you doing that for yourself, or are you doing it because of peer pressure? If you've been part of the hobby for a little while you'll have discovered that radio amateurs are everywhere, often in unexpected places. With that comes the realisation that this implies that we have members who represent all of humanity in all its many-splendored complexity. Where in that spectrum are you and what is your role in participating in that wider community, and is your role what you want it to be? One of the themes I've discovered over the years is insecurity. A recurring perception is that amateurs who've attained the highest license level are somehow "more" amateur than those who are on another journey. Where do you fit in that? How do you perceive amateurs with differing license classes? Do you apply the same metric to moped, car and truck licenses? How do you compare yourself against those who are not amateurs and how did you step into your license? I'm going to stop with the questions now and leave you with a thought. The hobby of amateur radio is a playground where you have the freedom to explore radio and all that it offers, but nobody said that you need to limit yourself to radio. I'm Onno VK6FLAB

Foundations of Amateur Radio Around the world are thousands of associations, groups of people, clubs if you like, that represent radio amateurs. Some of those associations are anointed with a special status, that of "member society" or "peak body", which allows them to represent their country with their own governments and on the international stage to the ITU, the International Telecommunications Union, through a global organisation, the IARU, the International Amateur Radio Union. Some of these are known across our whole community, the ARRL in the USA, the RSGB in the UK, and the WIA in Australia. Some much less so, the CRAC, the Chinese Radio Amateurs Club, or the ARSI, the Amateur Radio Society of India, for example. In an attempt to get a deeper understanding of what distinguishes these organisations, I visited a dozen member society websites. Cultural sensibilities and aesthetics aside, the variety and sense of priority is both pleasing and astounding. Starting close to home, the WIA, the Wireless Institute of Australia, shows news as the most important and the top story is a radio contact between the International Space Station and a school, held about two weeks ago. The ERAU, the Estonian Radio Amateurs Association, features an article about the 2025 General Meeting outlining who was there, what was discussed and thanking the participants for their contributions. When I visited, the ARRL, the American Radio Relay League, top news item, was the renewed defence of the 902-928 MHz Amateur Radio Band, from a few days ago. The most important issue for the ARRL is that you read the latest edition of QST magazine, but only if you're a member. The RSGB, the Radio Society of Great Britain, has an odd landing page that links to the main site, which features much of the same content. The latest news is "Mental Health Awareness Week" and encourages us to celebrate kindness in our community. The DARC, the German Amateur Radio Club, has a page full of announcements and the top one was an article about current solar activity including a coronal hole and various solar flares. The ERASD, the Egyptian Radio Amateurs Society for Development, uses qsl.net as its main website. It features many images with text, presumably in Arabic, that unfortunately I was not able to translate. Curiously the landing page features some English text that welcomes all interested to join. I confess that I love the juxtaposition between a Yaesu FT-2000 transceiver and the images of Tutankhamun and the pyramids. The RAC, the Radio Amateurs of Canada, use their homepage to promote its purpose, and features many pictures of their bi-monthly magazine, which you can only read if you're a member, which is where many of the homepage links seem to go. The RCA, the Radio Club of Argentina, is promoting the 2024-2025 Railway Marathon, including links to descriptions of what constitutes a Railway Activation, how to reserve your station, and upcoming and past activations. There's also a reminder to renew your license. The ARSI, the Amateur Radio Society of India, has a very sparse landing page showing their mission and not much else. Clicking around gives you lots of information about the history, activities, awards and the like. Unfortunately, I wasn't able to find out how to become licensed in India. There's hardly any images. In contrast, the URA, the Union of Radio Amateurs of Andorra, lands you on a page with contact details and not much else. Clicking through the site gives you lots of pictures of happy people and maps, lots of maps. The KARL, the Korean Amateur Radio League, features an announcement with a link to the 24th Amateur Radio Direction Finding, from a week ago, but it requires a login to actually read it. The JARL, the Japan Amateur Radio League, features an announcement to a form you can complete to join the "List of stations from which you do not wish to receive QSL cards." The NZART, the New Zealand Association of Radio Transmitters, features a big button to latest news and clicking on it shows the "Jock White Field Day", which was held several months ago. I wasn't able to see the CRAC, the Chinese Radio Amateurs Club, since the page didn't load for me. The "Wayback machine", also known as archive.org, from a capture a few days ago, showed a news item announcing the intent to organise the 1st Class C Amateur Radio Technical "something", I say "something" because I cannot actually load the article and see what it has to say. The event was scheduled for a month ago, the announcement was from several months ago. Content aside, finding sites was interesting too, mind you, there's plenty of member associations that don't have any web presence at all. Is that by choice, or necessity? The IARU list of member societies conflicts with the list of national organisations shown on Wikipedia. The IARU has about 160 entries, I say about, since the list isn't really formatted as much as it's congealed. Let's just say, perhaps a table for tabular

Foundations of Amateur Radio Since becoming a licensed amateur in 2010, I have spent a good amount of time putting together my thoughts on a weekly basis about the hobby and the community surrounding amateur radio. As you might know, my interest is eclectic, some might say random, but by enlarge, I go where the unicorns appear. Over a year ago I mentioned in passing a community called HamSCI. The label on the box is "Ham Radio Science Citizen Investigation", which gives you a sense of what this is all about. It was started by amateur radio scientists who study upper atmospheric and space physics. More formally, the HamSCI mission is the "Continuation and extension of the amateur's proven ability to contribute to the advancement of the radio art." If you visit the hamsci.org website, and you should, you'll discover dozens of universities and around 1,300 people, many of whom are licensed radio amateurs, who are asking questions and discovering answers that matter to more than just our amateur community. For the eighth time the HamSCI community held an annual "workshop", really, an opportunity to get together and share ideas, in person and across the internet, a conference by any other name. Under the banner theme of "HamSCI's Big Year", over two days, 56 people representing 27 different organisations across 61 sessions, tutorials, discussions, tours, posters and demonstrations, explored topics all over our hobby, from the Personal Space Weather Network, capable of making ground based measurements of the space environment, to the Whistler Catcher Pi, a project to record the VLF spectrum to 48 kHz using a Raspberry Pi. You'll find research into HF antennas for the DASI or Distributed Array of Small Instruments project and associated NSF grants, exploring measurements of HF and VLF, combined with GPS and magnetometer across 20 to 30 stations. There's discussions on how to explore Geospace Data, such as information coming from the Personal Space Weather Station network, or PSWS, using the OpenSpace project and dealing with the challenges of visualising across a wide scale, all the way up to the entire known universe. Did I mention that there's work underway to add PSWS compatible receivers to Antarctica? There reports on observations and modelling of the ionospheric effects of the April 2024 solar eclipse QSO party, including Doppler radio, HF time differences, and Medium Wave signal enhancements, not to mention planning and promoting future meteor scatter QSO parties. There's, post-sunset sporadic-F propagation, large scale travelling ionospheric disturbances, GPS disciplined beacons, the physical nature of sporadic-E propagation and plenty more. As you might have heard me say at one time or another, the difference between fiddling and science is writing it down. It means that you'll find every session has accompanying documentation, charts, graphics and scientific papers. Remember, there's eight years of reading to catch up with, or learn from, or play with. The publications and presentations section on the hamsci.org website currently has 526 different entries. You might not be interested in the impact of radio wave and GPS scintillation, or rapid fluctuation in strength, caused during the G5 geomagnetic storm that occurred on the 10th of May 2024, or a statistical study of ion temperature anistropy using AMISR, or Advanced Modular Incoherent Scatter Radar data .. or you might. In case you're curious, "anistropy" is the property of being directionally dependent, in other words, it matters in which direction you measure, which might have some relevance to you if you consider that we think of the ionosphere and radio paths being reciprocal. If it reminds you of isotropy, that's because they're opposites. The point being, that amateur radio is a great many things to different people. If you're a scientist, budding, graduate or tenured, there's a home for you within this amazing hobby. I'm Onno VK6FLAB