Foundations of Amateur Radio

Foundations of Amateur Radio Over the years you've heard me utter the phrase: "Get on air and make some noise!". It's not an idle thought. The intent behind it is to start, to do something, anything, and find yourself a place within the hobby of amateur radio and the community surrounding it. Since starting my weekly contribution to this community, thirteen years ago, almost to the day, I promise, this wasn't planned, you'll see why in a moment, I've been working my way through the things that take my fancy, things that are of interest to me, and hopefully you. From time-to-time I don't know where the next words are going to come from. Today they came to me five minutes ago when a good friend, Colin, VK6ETE, asked me what inspires me, after I revealed to him that I didn't know what I was going to talk about. That's all it took to get me rolling. There are times when getting to that point takes weeks, I do research, figure out how something works, explore how it might have been tackled before, if at all, and only then I might start putting my thoughts together, often I'll have multiple stabs at it and if I'm lucky, sometimes, something emerges that I'm astonished by. Today is much simpler than all that, since the only research required is to remember the people I've interacted with. Last week I met an amateur, Jess M7WOM, who was in town. Until last week, we'd never met and interacted only online. We discovered that we have a great many things in common. A joy for curiosity, exploration, technology, computers and a shared belief that we can figure out how to make things work. That interaction, over the course of a day, continues to fuel my imagination and provides encouragement to try new things. The same is true for a friend, Eric VK6BJW, who asked what they should do with the hobby after having been away for a long time with family, children, commitments and work. Just asking a few simple questions got the juices going and provided inspiration to start playing again. Another amateur was bored and claimed to have run out of things to do. A few of us started asking questions about their exposure to the hobby. Had they tried a digital mode, had they built an antenna, had they tried to activate a park, or as I have said in the past, any of the other 1,000 hobbies that are embedded within the umbrella that we call amateur radio. Right now I'm in the midst of working through, actually truth be told, I'm starting, Okay, actually, I've yet to start, reading the online book published at PySDR.org. Prompted by a discussion with Jess last week, I started exploring a known gap in my knowledge. I likened it to having a lamp-post in front of my face, I can see to either side, but in-between is this post, obscuring an essential piece of knowledge, how one side is connected to the other. In my case, on one side, I can see the antenna, how it connects to an ADC, or an Analogue to Digital Converter. On the other, I can also see how you have a series of bytes coming into your program that you can compare against what you're looking for, but the two are not quite connected, obscured by that .. post. I know there's a Fourier Transform in there, but I don't yet grok how it's connected. Recently I discussed using an RDS, or Radio Data Systems decoder, called 'redsea', connected to 'rtl_fm', in turn connected to an RTL-SDR dongle, that is, you connect an antenna to a cheap Digital TV decoder, tune to an FM broadcast station and use some software to decode a digital signal. It turns out that the PySDR book serendipitously uses this signal path as an end-to-end tutorial, complete with all the code and example files to make this happen. I actually read the chapter, but it's assuming some knowledge that I don't yet have, so I'm going to start on page one .. again. So, what has this got to do with Inspiration, you ask. Well, everything and nothing. Inspiration doesn't occur in a vacuum. It needs input. You cannot see light without it hitting something, radio waves don't exist and cannot be detected until it hits an antenna, the same is true for inspiration. It needs to hit something. You need to react, it needs to connect. That is why I keep telling you to get on air and make some noise. I'm Onno VK6FLAB

Foundations of Amateur Radio Much is made in our hobby about working DX, that is sending and receiving distant radio signals. How distant is up for debate. Depending on where you are, DX might be outside the continent, outside the country, or in my case you could easily say, anything outside of my state, since the nearest border is about 1,240 km away from here. For giggles, the distance between Albany in the South West and Wyndham in the North East of the state is 2,400 km and that's via radio wave. By car it's 3,570 km. To be clear, we're still inside VK6. All that to say, DX is in the ear of the beholder. If that's not enough, there's a group of amateurs who are of the strident opinion that for DX to count it must be a two-way contact. That is, both stations need to hear each other and as such, those amateurs believe that a mode like WSPR, the Weak Signal Propagation Reporter can't possibly be considered DX, even if you can discover that your station was heard on the other side of the planet. I'm going to skip right over those who tell anyone who will listen that FT8 isn't real radio because it's just computers talking to each other. This to give you some context when I introduce the next idea, namely FM Broadcast DX. I'm acutely aware that this isn't amateur radio, there's no two-way communication, it's probably not DX and besides, it's computers. That out of the way, let me tell you about something I discovered. Many, but not all, FM broadcasters transmit multiple signals when you tune to their station. One of those is a signal called RDS, or Radio Data Systems. It's used to show you the name of the station, sometimes what song is playing, what style of station it is and other information like road traffic alerts and emergencies. You can decode this using an RDS decoder. Recently I was browsing YouTube. I came across a video on the Broken Signal channel that digs into the world of FM-scanning to log any RDS information for the purpose of finding DX stations. The video goes into great detail on how to set this up with Windows, by copying files into various places, updating XML files, configuring sample rates, connecting virtual audio cables, running several tools simultaneously and it goes on to demonstrate how this all hangs together. While I was impressed with the idea, the implementation didn't speak to me, since I wince at the notion of copying random files into an application installation directory and besides I'm a Linux user. So, I went hunting. Turns out that there is an RDS decoder for Linux, called "redsea", written by Oona OH2EIQ. It's on GitHub. Compiling it is pretty straightforward, follow the instructions and it should work as advertised. You'll also need to have "rtl-sdr" installed so you can run a tool called "rtl_fm". Again Oona's instructions should help you out. I will add that I'm assuming that you have a so-called RTL-SDR dongle, it's a cheap USB device that can be coerced into pretending to be a software defined receiver with about 2.2 MHz of bandwidth. Based on the example shown, I immediately tuned to a local station and RDS information started filling my screen. To let you know how simple this is, you run the "rtl_fm" tool and send its output to "redsea" which decodes the information and displays it on the screen. That's it. No more moving parts, no XML files, no shenanigans with virtual audio cables and the like. Stage one complete, on to stage two, scanning. The "rtl_fm" tool has the capability to scan a range of frequencies. I tried this, but didn't really get anywhere, since for the scanner to work you need to set the squelch in order to switch between frequencies, but if you're aiming for a weak signal, it will never be heard if your local FM broadcasters are belting away 24 hours a day. So, instead I'm scanning each frequency between 87 MHz and 109 MHz, every 10 kHz, for 10 seconds, to see if there's any RDS data to be heard. I send that to a file and when I feel the urge, I can go check to see what I've heard. I haven't yet put this up on GitHub because I'm considering making it a contribution to the "redsea" project instead of a project of my own. Now, at this point you might wonder what all the fuss is about. Well, the same method could be used to decode your local amateur repeater idents, or the NCDXF beacons, or any other kind of interesting information. I saw one user link "rtl_fm" to "multimon-ng", a tool I've spoken about before. You should also check out Oona's website, windytan.com, there's a whole range of signal processing stories to be found, including dealing with flutter distortion on Steamboat Willie and a very cool spiral spectrogram. I'll leave you with one question. Why haven't you installed Linux yet? I'm Onno VK6FLAB

Foundations of Amateur Radio Some life lessons require additional reinforcement from time to time. This week I was strongly encouraged to remember a lesson that can be summarised as: "A place for everything and everything in its place." It was first uttered like that to me a quarter of a century ago by a client who used it frequently around their staff. It means that all the stuff that fills up the space around you, in this case, physical stuff, needs to have a specific home and if you're not actively using it, that is where it should be. This is useful in a context where you have lots of little things that you need from time-to-time, or if you have several people dependent on the availability of a single thing, like say the labelling machine used to tag equipment. The other day an incident involving a tiny tablet that went flying across the kitchen bench, bounced over the edge and vanished, not helped by the fact that taking the tablet was time sensitive and the fact that the vacuum cleaner was right there - no the tablet was not inside, I checked. I walked around the bench to the other side and started rolling on the ground with the aid of the torch on my phone. Ten minutes in, still nothing. I remembered that my go-bag has a torch, so I went to get it from its place. One problem, it wasn't there. I turned the bag upside down and went through it. Nope, no torch. That's two things that vanished. Neither has resurfaced at this point. I went to the chemist to get another tablet and took it 40 minutes late. The torch however was not so easy to resolve. My, what I call go-bag, has a bunch of life affirming essentials. It started pretty soon after becoming a radio amateur. It has two jumpers, long-leg underwear, an under shirt, a towel and a microfibre cloth, leather gloves, mosquito net, medication, band-aids, toilet paper, soap and some empty bags. It also has a torch, well, not right now it doesn't. After failing on my mission to locate the torch, I started stuffing the contents of my go-bag, straight back into its bag, only to realise that I wasn't helping future me. I stopped, pulled everything back out and started folding everything neatly. Then I repacked the bag. I've put in a stand-by torch, in Dutch they're called a "knijpkat", or a mechanically operated torch. You squeeze it in your hand and in doing so you move a dynamo that charges either a battery or a capacitor. It's called a "pinch cat" because it sounds a little like that. The light is fine for getting around in the dark, but you wouldn't mistake it for a super bright, eyeball burning, LED torch. In case you're wondering why I'm going into such detail about this, it's because you never know when you need something. It might be urgent, or it might not be. Having your stuff organised in such a way that you can find it, can sometimes be the difference between life and death. Now I get it. Not everyone works like this. I have for decades had a system on my desk where I know where all the bits of paper are and it's not helpful if someone cleans it up, because at that point I have no reference to anything and I will have to go through the whole box of things to find what I need. When my partner and I travelled around Australia in an Iveco Daily stuffed to the gunnels with electronics equipment, clothes, food, camping gear, a two metre satellite dish and plenty of other things, I had a system that involved four filing cabinets bolted into the van, combined with a dozen or more crates, metal hooks, straps and a safe. I was forever putting things away in the exact same place, each time. It's not a process that comes naturally to everyone and so we settled on a process where I would pack the van so I could lay my hands on anything within seconds, from the socket set to the satellite signal finder, from a clean pair of shorts to a raincoat, from a fuel funnel to a water funnel. Pro-tip, don't mix the two. Tools aside, of course this system also applies to the first aid kit and the fire extinguisher, the fire blanket, band-aids and medication, and in this case a torch. You might ask how this could apply to amateur radio. Go-bag aside, looking around my radio shack, it has lots of little things, like adaptors, measuring gadgets, chargers, fly leads, microphone clips, coax switches and plenty of other stuff. If everything in your shack is in use, this isn't an issue, but if you're like me and don't have your NanoVNA, and all the SMA to something adaptors, or plenty of other things lying around for that "just in case" time, then having a place for everything and everything in its place is a very productive way to keep things organised so you don't spend half your life looking for things. Similarly, if you know where your portable shack is, your battery charger, an emergency antenna, or some other essential item, you'll discover that when it comes down to the pointy end of a situation, this might make a difference. So, how do you keep your life, and shack, org

Foundations of Amateur Radio In the early 1920's long distance communication using radio was a growing interest. At the time it was thought that communication that we take for granted today, over long-distance HF, was limited to long wave or extremely low frequencies, the lower the better. With that restriction came massive antennas and high power transmitters, available only to commercial and government stations. Then radio amateurs let the cat out of the bag by discovering that so-called "short wave" radio could be heard all across the globe. As an aside, today, "short wave" seems quaint, because we've discovered that even shorter waves can be used to communicate, right down to nanometre communication as shown by NASA in its XCOM technology demonstration on the 12th of May, 2019. On a daily basis we use 120 mm and 60 mm waves when we use 2.4 and 5 GHz Wi-Fi for example. As a result of the discovery of short wave radio, a gold-rush emerged. There was a hunger in the community for radio, businesses and communities adopted the new medium, there were radio courses being taught in Universities, church services and other forms of entertainment started filling the airwaves. Comedy, talk shows, music, concerts, serials and dramas spread across the electromagnetic spectrum and radio amateurs who had discovered the phenomenon were running the risk of being pushed aside by commercial interests willing to pay for access. As I've said before, in many countries at the time, amateur radio was actively discouraged, sometimes it was even illegal. Before we continue, I should quote some statements made about radio before the gold-rush which at the time was seen as "Telegraphy Without Wires". In 1865 a Boston Post editorial proclaimed: "Well-informed people know it is impossible to transmit the voice over wires and that were it possible to do so, the thing would be of no practical value." Lord Kelvin, President of the Royal Society, said: "Radio has no future." and went on to say: "Wireless is all very well but I'd rather send a message by a boy on a pony", he also said: "Heavier-than-air machines are impossible." and "X-Rays will prove to be a hoax." Not all statements aged as badly. The New York Times said in 1899: "All the nations of the earth would be put upon terms of intimacy and men would be stunned by the tremendous volume of news and information that would ceaselessly pour in upon them." Back to the IARU. Before a business trip to Europe, the board of directors of the ARRL asked their President, Hiram Percy Maxim, to encourage international amateur relations, which on 12 March 1924 resulted in a dinner given, at the Hotel Lutetia in Paris according to Hiram, a "certain dining room" by "the most distinguished radio men of Europe." Hiram goes on to say that: "This A.R.R.L. President has sat in at a good many very impressive radio meetings in the past, ranging from Maine to California, but he has never sat in at a meeting where there was quite as much thrill as at this meeting in Paris where the amateurs of nine different countries sat down together." The countries were, France, Great Britain, Belgium, Switzerland, Italy, Spain, Luxembourg, Canada and the United States. Hiram remarks that "Denmark was represented by a letter in which regret was expressed at the inability to have a representative present and asked that the amateurs of Denmark be counted in." You should dig up a copy of the May 1924 edition of QST to get a sense of occasion where the ARRL president compares the thrill of the "hamfest" to the atmosphere during that dinner and pities those who have never experienced it. During the meeting it was decided to form an organisation which was going to be called the International Amateur Radio Union. A temporary committee was formed that appointed Hiram Maxim as the chair and Dr. Pierre Corret as secretary to take charge of the details to create a permanent organisation. The final decision was to call for a general Amateur Congress on the Easter Holiday of 1925 where the IARU would be formalised. On the 14th of April, 1925, 250 radio amateurs from 23 countries met in Paris and over the next four days the details of the new Union were hammered out. Among those details were that the organisation was chiefly for "the coordination and fostering of international two-way amateur communication, that it should be an organisation by individual memberships until strong national societies had been formed in the principal nations and a federation would be feasible, and that its headquarters would be located in the USA." The constitution was written over a day and night session and by the morning of the 17th of April, every delegate had a copy and then the hard work began, approving the constitution, section by section, by the entire Congress. On the morning of the 18th, elections were held and Hiram U1AW was elected international president, Gerald G2NM, international vice-president, Jean F8GO and Frank Z4AA councillors-at-l

Foundations of Amateur Radio A great deal of energy is expended on the notion of operating portable. I've talked about this plenty of times. Issues like power, antennas, suitable radios, logging, transport and time of day all come to mind. Some activities are framed specifically as portable operations. Things like Summits On The Air, or SOTA, Parks On The Air, or POTA, World Wide Flora and Fauna, or WWFF. There's field days, portable contests and specific activities like the 2014 activation of FT5ZM on Amsterdam Island and the 2016 activation of VK0EK on Heard Island. I mention those last two specifically since I had the distinct pleasure of meeting those teams and had the opportunity to interview each amateur whilst enjoying a typical Aussie BBQ. I'll point out that no shrimps were thrown anywhere. You can find those interviews with FT5ZM and VK0EK on my website at vk6flab.com. Each of these activities are framed in the context of the activity, as-in, you climb a mountain with a radio and then you make noise. That's not the only way to go portable. One of my friends checks in to the weekly F-troop as a portable station most weeks. Glynn VK6PAW gets in his car, drives to some random location and participates from wherever he happens to be at the time. In doing so, the radio part of it, is the add-on between leaving home and arriving at a destination for a cup of coffee. Charles NK8O works all over the United States. When he checks into F-troop, he's rarely in the same place two weeks in a row. In between work and sleep you'll find him activating a nearby park. He's been doing this for quite some time. While this is a POTA activity, he finds parks that fit into his life, rather than point at a park and make a specific trip there to activate it. Before I continue, I'd like to mention that I'm not dismissing making a specific trip. Far from it. The point I'm making is that making any such trip is extra work. It's an added activity in your life. Whilst entirely enjoyable, there's plenty of times where that's just not possible. Instead I'd like to look at this from the other side. Both Glynn and Charles have a radio with them. Perhaps not all the time, but often enough that they can activate their station when they happen to be in a suitable location. I've similarly put a radio into my luggage when going on a holiday. It might transpire that it stays there, or it might be that I happen to find a picnic table at the side of a water reservoir that happens to be in the shade and just begging to try a radio at. In other words, if you have a radio handy, you can handily use it when the opportunity comes to pass. So, what do you bring with you? If you're like Charles, you'll have a QRP radio, a Morse key, a battery and a wire antenna. Glynn has a vertical that lives in his car and the radio is bolted in. For a while I had my radio permanently mounted in my car and I suspect that will return there in the not too distant future. It was removed for a service that involved the transmission being replaced after it failed after only a 140,000 km on the clock. Thankfully a fellow amateur had a spare car we could use, but I wasn't game to drill holes for an antenna and I'm pretty sure they were pretty happy about that. The more I look at the activities that others report on, the more I have come to realise that the people who get on-air the most are the ones who have found a way to weave radio into their day-to-day life, rather than rely on specific amateur radio activities and plans. I confess that I miss sitting by a local lake making noise or finding a random car park with shade that is just begging for someone, anyone, to turn on a radio and have a go. So, how do you approach radio in your life, and how might you find ways to incorporate it into the gaps? I'm Onno VK6FLAB

Foundations of Amateur Radio As a self-proclaimed radio nerd I'm aware of the various amateur bands. Depending on your license, your familiarity will likely vary. I've never been on 6m for example, but I have a good working relationship with the 10m band. Amateur bands aside, there's plenty of other activity across the radio spectrum. It occurred to me that I've never actually stopped to take note of what specifically I can hear from my own station. Think of it as a station frequency survey. Obvious sources are AM and FM radio broadcasters. Then there's the aviation frequencies, the local control tower, arrival and departure frequencies as well as Perth airport ground on occasion. There's the ATIS, the Automatic Terminal Information Service. There was a time when I could hear various aviation non-directional beacons, or NDBs, that are near me, but many of them were switched off in 2016. I haven't yet found a current list of which of the 213 remaining navigation aids that form part of the Backup Navigation Network across Australia are still on the air. As it happens, there's currently some horrendous noise on HF with several new potential sources that I have not yet identified, a pool pump, a bank of solar panels, plasma TV, you name it. Staying with aviation, I've briefly played with Automatic Dependent Surveillance-Broadcast, better known as ADS-B, or ADSB, on 1090 MHz. If you have a PlutoSDR, I updated the dump1090 program to use Open Street Map several years ago. You can find it on my VK6FLAB GitHub page. If you want to see some very interesting visualisations for ADSB, have a look at the adsb.exposed website. Further up the frequencies are things like 2.4 and 5 GHz Wi-Fi. In a previous life, before I was an amateur, I played with Ku-band satellite frequencies in the range between 12 to 18 GHz, specifically DVB-S, or Digital Video Broadcasting - Satellite. While that's an impressive list of things, it leaves an awful lot of unexplored territory. For example, the local trains and public transit authority, the fire and emergency services, the volunteer bush fire brigades, water bombers and the like. I've not even looked at local digital services like DVB-T, that's the terrestrial standard, or the local radio version, DAB+, or Digital Audio Broadcasting. Then there's pagers, and countless marine services and channels, the ubiquitous CB frequencies and a couple of pirate ones, and global services like GPS, weather satellite and other Earth monitoring services. Note that I'm specifically highlighting things that I can hear at my station, or more precisely, should be able to hear. I'm in the process of figuring out which particular tools I need to actually have a stab at hearing and decoding things like weather satellite. I wouldn't be me if I didn't try this with my hands tied behind my back. I'm limiting myself to things I can hear using the antennas that I already have. I don't, well not at this stage, want to start building and installing more antennas, probably because in the not too distant future I plan to finally erect a replacement HF antenna, but that's a story for another day. As for now, I'm plotting noise levels using a tool called rtl_power. I'm working on figuring out what extra noise has joined my environment. I'm also starting to make a concerted effort to document specifically what I've actually heard. Not so much a continuous log, more of a one-way log if you like, some might call it a shortwave listener log. What RF sources have you heard in your shack and how many of them did you document? I'm Onno VK6FLAB

Foundations of Amateur Radio The other day I had an interesting exchange with a contest manager and it's not the first time I've had this dance. As you might know, pretty much every weekend marks at least one on-air amateur radio contest. Following rules set out by a contest the aim is to make contact or a QSO with stations, taking note of each, in a process called logging. Using logging software is one way to keep track of who you talked to, a piece of paper is another. If your station is expecting to make less than a dozen contacts per hour, paper is a perfectly valid way of keeping track, but it's likely that most contests expect you to transcribe your scribbles into electronic form. Which electronic form is normally explicitly stated in the rules for that contest. While I mention rules, you should check the rules for each contest you participate in. Rules change regularly, sometimes significantly, often subtly with little edge cases captured in updated requirements. On the software side, using electronic logging, even transcribing your paper log, can get you to unexpected results. I participated in a local contest and logged with a tool I've used before, xlog. Contests often specify that you must submit logs using something like Cabrillo or ADIF. There are contests that provide a web page where you're expected to paste or manually enter your contacts in some specific format. Using xlog I exported into each of the available formats, Cabrillo, ADIF, Tab Separated Values or TSV and a format I've never heard of, EDI. The format, according to a VHF Handbook I read, Electronic Data Interchange, was recommended by the IARU Region 1 during a meeting of the VHF/UHF/Microwave committee in Vienna in 1998 and later endorsed by the Executive Committee. The contest I participated in asked for logs in Excel, Word, ASCII text or the output of electronic logging programs. Based on that I opened up the Cabrillo file and noticed that the export was gibberish. It had entries that bore no relation to the actual contest log entries, so I set about fixing them, one line at a time, to ensure that what I was submitting was actually a true reflection of my log. So, issue number one is that xlog does not appear to export Cabrillo or ADIF properly. The TSV and EDI files appear, at least at first glance, to have the correct information, and the xlog internal file also contains the correct information. Much food for head-scratching. I'm running the latest version, so I'll dig in further when I have a moment. In any case, I received a lovely email from the contest manager who apologised for not being able to open up my submitted log because they didn't have access to anything that could open up a Cabrillo file. We exchanged a few emails and I eventually sent a Comma Separated Values, or CSV file, and my log was accepted. What I discovered was that their computer was "helping" in typical unhelpful "Clippy" style, by refusing to open up a Cabrillo file, claiming that it didn't have software installed that could read it. Which brings me to issue number two. All these files, Cabrillo, ADIF, TSV, CSV, EDI, even xlog's internal file are all text files. You can open them up in any text editor, on any platform, even Windows, which for reasons only the developers at Microsoft understand, refuses to open a text file if it has the wrong file extension. This "helpful" aspect of the platform is extended into their email service, "Outlook.com" previously called "Hotmail", which refuses to download "unknown" files, like the Cabrillo file with a ".cbr" extension. With the demise of Windows Notepad, another annoying aspect has been removed, that of line-endings. To signify the end of a line MacOS, Windows and Linux have different ideas on how to indicate that a line of text has come to an end. In Windows-land, and DOS before it, use Carriage Return followed by Linefeed. Unix, including Linux and FreeBSD use Linefeed only; OS X also uses Linefeed, but classic Macintosh used Carriage Return. In other words, if you open up a text file and it all runs into one big chunk of text, it's likely that line-endings are the cause. It also means that you, and contest managers, can rename files with data in Cabrillo, ADIF, CSV, TSV, EDI and plenty of other formats like HTML, CSS, JS, JSON, XML and KML to something ending with "TXT" and open it in their nearest text editor. If this makes you giddy, a KMZ file is actually a ZIP file with a KML file inside, which is also true for several other file formats like DOCX to name one. Of course, that doesn't fix the issues of broken exports like xlog appears to be doing, but at least it gets everyone on the same page. Word of caution. In most of these files individual characters matter. Removing an innocuous space or quote might completely corrupt the file for software that is written for that file format. So, tread carefully when you're editing. What other data wrangling issues have you come across? I'm Onno VK6FLAB

Foundations of Amateur Radio Did you know that on the 18th of April, 1925 a group of radio amateurs had a meeting in Paris? During that meeting they formed an organisation that still exists today. Before I get into that, let me share a list of names. - Wireless Institute of Australia - Radio Amateurs of Canada - Radio Society of Great Britain - Vereniging voor Experimenteel Radio Onderzoek in Nederland or if you don't speak Dutch, can't imagine why, the Association for Experimental Radio Research in the Netherlands, - Deutscher Amateur Radio Club, I'll let you figure out what that translates to, - American Radio Relay League Language aside, one of these is not like the other. Once upon a time, in a land far, far away, at a moment likely before either of us was born, Hiram, wanted to send a message from his amateur station in Hartford to a friend in Springfield. That's 26 miles, or less than half an hour up the road via I-91. One minor problem. At the time, in 1914, using amateur radio for anything beyond 20 miles or so was considered a miracle, so Hiram asked a mate at the halfway point in Windsor Locks to relay a message on his behalf. Soon after he convinced his local radio club in Hartford that building an organised network of stations to relay amateur radio messages was worth doing and the American Radio Relay League was born. Co-founded with radio experimenter Clarence Tuska, Hiram Percy Maxim became its first President. He held many callsigns, most recently W1AW. At the time, longwave, the longer the better, was considered the pinnacle of communication technology. The airwaves were becoming crowded, so amateurs, in search of more space and always up for a challenge, started experimenting at the edges. The shortest wavelength available to amateurs at the time was the 200m band, or 1,500 kHz. In December 1921 the first successful transatlantic transmissions were achieved. Hundreds of North American amateurs were heard across Europe on 200m and several were heard in reply. In a dance that continues to this day, new technology replacing old, spark gap transmitters were replaced by vacuum tubes and using those amateurs were able to use even shorter wavelengths. While technically illegal to operate on higher frequencies, the authorities put their fingers in their ears and let those crazy amateurs play on those useless bands. This is a world without international prefixes, no VK, PA or G stations, so amateurs were forced to come up with their own system to indicate the continent and country. This was clearly organised chaos at the edges of legality, in many countries amateur radio operation was actively discouraged or even illegal. Soon the same person who came up with the notion of the ARRL led the way and organised a meeting in Paris. That meeting, on the 18th of April, 1925 marks the forming of the IARU, the International Amateur Radio Union and as I said, it exists today. That date, the 18th of April is globally, well at least in the amateur radio community, uh, well, small pockets of the amateur radio community, known as World Amateur Radio Day. 2024 marks the beginning of a year of celebration for the centenary of the organisation that brought together this global rag-tag group of enthusiast experimenters that we fondly refer to as our community. The IARU theme for this year is: "A Century of Connections: Celebrating 100 years of Amateur Radio Innovation, Community, and Advocacy" and you're invited. So, what types of activities are you planning, what kind of celebration do you have in mind, and who is bringing the birthday cake? I'm Onno VK6FLAB

Foundations of Amateur Radio During the weekend I participated in a contest. Before you get all excited, it was only for a couple of hours over a few different sittings and while I had plenty of fun, of the eleven QRP, or low power, contacts I made, nine were on VHF and UHF, two were on 10m HF. Mind you, 3,200 and 3,500 km contacts are nothing to sneeze at. It has been a while since I've actually been on HF, so long that it felt like turning on a new radio and getting used to it all over again. If you're not sure what I'm describing, let me elaborate. A new radio takes a few goes to calibrate your ear and brain to learn what you can expect to hear and work. On some radios if you can hear the other station, you can work them. On others, unless they're pegging the S-meter, you've got no chance. QRP adds an extra layer of challenge. A few hours earlier I'd been discussing HF band conditions and one comment that stuck in my mind was that the bands appeared to be more quiet than normal. At the time, nobody could put a finger on why or how, but there appeared to be a general consensus that this was the case. So when I tuned to 10m, after having switched off my beacon, which I promptly forgot to turn back on for 36 hours or so, I went hunting for stations to contact. I heard a few, but their signals were very weak. Noise levels were amazing, very quiet, but stations were very low down. I thought nothing of it, given the discussion we'd just had, and persisted and as I said, I made two contacts. Since contacts were hard to come by, I started playing with another experiment I'm working on. Specifically I'm using something called USBip to connect to some USB devices across my network. The way it works is that you plug the devices, like a CAT cable and a USB sound-card into a Raspberry Pi, then using another computer, you can access those devices wirelessly as-if they're physically connected to the other computer. This is useful if you don't want to subject an expensive computer to any stray RF that might be coming in via a USB port. I've written some hot-plug support for this, so you can just connect and disconnect USB devices without needing to fiddle. You'll find the code on my github page. Given that stations were few and far between and not staying in one place, I moved to a local AM broadcast station, so I could test the USBip sound-card link and all I heard was absolute garbage audio coming from that station. I turned on another radio and it too had the same rubbish audio. After a couple of hours fiddling with RF-Gain and still not getting anywhere I started searching online for an answer. One thread, 27 posts long, seemed to describe what I was hearing. Bill N8VUL supplied the answer: "Make sure AGC is on" So, no. It wasn't, on either radio. Why it was off on both radios I will never know. It did make me start exploring again just what other settings I have access to on my radio and what they sound like. Turns out that there's not a lot to be found that has any basis in fact. There were a lot of videos showing amateurs pushing lots of buttons uttering phrases like: "Can you hear the difference?" with nothing much materially changing. The closest to something useful was a YouTube video by Doug N4HNH, called "ATT, IPO, [and] RF Gain" in which he shows some of the effects of each of those options on a Yaesu FT DX 5000. One thing I noticed is that the radio has a neat display that shows the signal path as it passes from a selected antenna through those options and more, highlighting which ones are in use. I started hunting around to see if such a block diagram exists for my FT-857d. Unfortunately I didn't manage to find any such diagram, not even for another radio. The closest I got was the image on page 30 of the FT DX 5000 Series Operating Manual. I did learn that the attenuator on my radio is 10 dB and it doesn't function on 2m and 70cm. As for the AGC, the user manual doesn't help much. It states that it's used to disable the Automatic Gain Control and normally it should be left on. There's some discussion around the interaction between the "RF Gain" knob and the AGC, but I must confess that finding useful examples of this managed to elude me. At this point I have no idea what the difference is between the block diagram on the FT DX 5000 and my FT-857d, other than the obvious single antenna port and plenty of missing features. I find it surprising that for a radio that was introduced over 20 years ago, this kind of information appears to be lacking. Especially since it would help any new amateur operate their radio better and understand the impact of each particular setting on the signal that they were hearing. If you know of any such resource, reach out, my address is [email protected] Meanwhile I'm going to spend some quality time with my radio and the manual and see what other hidden gems I can find and if you know me at all, you'll know that this isn't the first, second or even third time that I'm going throu

Foundations of Amateur Radio Whenever I'm out in the bush in the process of erecting some or other wire contraption, uh, antenna, I cannot help but think of the iconic Australian rock band, Skyhooks, not for their glam rock inspired music, nor for their pure mathematics and computer science degree holding guitarist, but for their name. In antenna erection, a skyhook is called for when you point at a spot in the sky and will into being an attachment point for the wire antenna in your hand. It's always in the perfect spot, holds any weight and of course it's made from unobtainium. Absent a skyhook, there are other ways of hoisting an antenna into the air. A recent discussion revealed that in some places catapults and trebuchets are frowned upon, if not outright illegal. Can't imagine why. Depending on their size, they may be difficult to transport. In the same vein, antenna launchers, lightly camouflaged spud guns, are essentially a gas pressurised tube, causing a projectile to be launched by releasing a valve. Those too are pretty restricted and for good reason. Fortunately there are plenty of other ways of getting things to be in the right place. Let's explore. One option is to bring along a pole, made from whatever is at hand, a multi-element fibreglass pole made by Spiderbeam, mine is 12m long, has always worked for me, though I will confess that I have managed to break one. It did take a 135 degree bend in the tip to achieve that. I'll hasten to add, I didn't set out to do that. Previously it had easily sustained 90 degree abuse in heavy wind. I purchased a new one. I've used it for years. It's not cheap, but it works. Alternatives, much less strong, are using fishing rods or much less flexible, aluminium tubes, pool cleaning extension poles, even painters poles and at a pinch, lengths of wood screwed together, or if you're a Scout, logs lashed into some contraption. Then there's using the nearby landscape. Getting a wire into a tree is an activity that's fun for young and old. Not so much for the person attempting it. Often this starts with throwing things at the tree. You might find a spanner, tie it to a rope and whirl it around, letting go at just the right moment to get it to where you're going. This is not a safe activity and not recommended away from emergency medical assistance, you've been warned. This graduates to using things like a monkey's fist knot. I was given a brightly coloured one, lovingly hand crafted by Alan VK6PWD. It's reminiscent of a Sea Scout woggle knot. Truth be told, it's too beautiful to use, or rather risk losing. Tie it to a line and whirl and throw. Then there's the arborist throw bag, same deal. Each of these whirling activities are fraught. Mainly because you need to strike a balance between the strength of the line, strong enough to be chucked, uh, thrown, but weak enough that you can break it if it gets caught and believe me, it will. There's the option of co-opting your dog's ball launcher. Tie a rope to the ball and hurl. Success depends on how quick your dog is in catching low flying tennis balls. The last time I went fishing was in 2003 when I used a string and a safety pin to catch an, admittedly, tiny fish at Harry's Hole using a tiny piece of bread, took all of 5 minutes. That said, I have a new fishing rod, well, it was new when I purchased it, but now it's a couple of years old. It was the absolute cheapest one I could find. I also bought a box of sinkers. Purchased on the advice of Bob VK6POP, I've used that rod many times to launch a sinker at a nearby tree and used it to pull through some line and then an antenna. It's still a balance between using a fishing line that's strong enough to handle the weight of a sinker and weak enough to break when you want to. The sinker needs to be just the right weight too. Too light and you'll launch it at the right branch where it will stay for the rest of the life of the tree. Too heavy and it will end up somewhere in the bush, never to be found. Grey sinkers tend to vanish in the grass, so if you can find it, look for something nice and bright, fluorescent is best. In a pinch you can use a couple of sinkers, like when you've run out, but in my experience they tend to wrap themselves around a branch. Of course you could also just climb into a tree, or hire a cherry picker, but I'm not that flexible, either in my joints or wallet, so those options don't do it for me. If you have a friendly arborist nearby, there's no shame in paying them to attach a pulley to the required branch in your backyard. Just make sure that the line you use on the pulley cannot escape the groove and get jammed between the wheel and the cheek, don't ask me how I know. So, what ways do you use to summon a skyhook and does it include a Siberian jukebox? I'm Onno VK6FLAB

Foundations of Amateur Radio So, the 19th of February 2024 came and went. As it was, my day started with the highest minimum that month, 27.5 degrees Celsius, that's the minimum overnight temperature. The maximum that day here in Perth, Western Australia was 42.3 degrees. The day before was the highest maximum for the month, 42.9. If you're not sure, that's over 109 in Daniel Gabriel Fahrenheit's scale. That same day the Australian regulator, the ACMA, launched a new era in Amateur Radio. Moving from personal amateur licenses we legally became part of a class license regime. We have the option to hand our license back and get a refund, but the cautious side of me prevailed and I've not yet handed back my license, since it's currently the only proof that my callsign is valid, the one issued to me in December 2010. I contacted the ACMA to ask about this and was told that they were having display issues with their system and was sent an image showing both my callsigns and email address. I'm not saying that I don't trust the person sending this to me, but I'm fairly sure that "but your honour, it was in an email" isn't going to cut it if push comes to shove. Curiously my name appears to be missing, showing the word "Blank" instead. Their IT team has been working on displaying F-calls for weeks now. I mean, seriously, these were first issued in 2005. Do we really need to spell this out? The ACMA continues to actively encourage amateurs to hand in their license and points out that any delay in doing so will reduce the amount that may be due. It also points at Schedule 4, Part 2 subclause (7)(1)(d) of the Radiocommunications (Amateur Stations) Class Licence 2023, to assure me that my callsign is mine and mine alone, irrespective of what's in the register. It goes on to say that the letter they sent back in January, the one they had to resend, since they got my callsign details wrong, explained that I could hand back my license and that my ability to operate hinged on my qualification, not my callsign. Here's the rub. Let's say that I'm qualified and that the letter I have proves it. I am required to identify myself on-air, the regulations say so. This means that in order for me to claim that I am who I say I am, there needs to be a register with that callsign. Apparently I'm in the register, but nobody other than the regulator can prove that. One thing that appears to be missing is a solid understanding that the register of callsigns is used by the amateur community to determine if a callsign heard on-air is assigned or not. I mean, I could call myself VK6EEN and without the register who's to say that it's mine? It's not confidence inspiring to say the least. Then there's the register itself. There's an online component, which you can use to search for a callsign. As I said, mine isn't visible, neither is any other four letter F-call. As a test, I've been scrolling, one page at a time, for the past hour, to get to VK6F, starting at VK6A, to see if it shows up, but I'm not holding my breath. For some reason the developers who built this appear incapable of rendering a simple table in anything less than 36 seconds per page, so much so that Chrome thinks that the page has crashed and offers to kill it, every time. Funnily enough, if you extract the URL from within the page and copy it, you can download all 176 pages for VK6 callsigns in less time than it took me to write this sentence. Unsurprisingly, F-calls are not there. Did I mention that this software, released a month ago, is already using depreciated features in my current web browser, which came out a week before the new register went live? It gets better. If you actually want to manage your callsign, you need to create an account on the regulator's portal, called ACMA Assist. When you load the ACMA Assist URL and click the "Sign up or log in" button, 134 different URLs from all over the Internet are hit, across 34 different domains, including Facebook, Google, Microsoft, LinkedIn, Markmonitor, Monsido, several content, font, icon and javascript libraries, and plenty more. This is a Government website, requiring that I authenticate to it, and to do that, I'm required to provide more identity documents than the tax department needs and wait for it, authentication is outsourced to some random domain, so you're entering your details into a third-party service. You have the choice of using the Government identity provider, one that requires a mobile phone and an app, or use a Government owned company that prefers a mobile and a different app, but offers access via a website on yet another domain. Now it gets funky. If you pick "driver's license", you'll discover that everything that's on your license is information that the form wants. So anyone with a photo of your license can sign up and identify as you, like the chemist who required a photocopy of it so you could buy Sudafed for your debilitating hay fever, because instead, you might use it to create methamphe

Foundations of Amateur Radio When you operate your station portable, either for fun, or for points, you might be surprised to learn that getting on air and making noise isn't quite as simple as bringing a radio and turning it on. Aside from the need for a reliable power supply, batteries, generator, solar panels, or a magic mains socket, there is the requirement for bringing enough gear to get on air, but not so much that setting up takes days, or even hours. The decisions you make are influenced by where you decide to operate from. If you want to stay in your car, the location is not nearly as influential as when you decide to find a park where you want to have some fun. Finding a location is not a trivial process. If you only plan to get on air for an hour to activate a park, you pretty much get what you find, but if you plan to be on air during a contest for the day, other things start to come into focus. For example, what are the toilet facilities like, are we digging a hole, or is there a public facility nearby? Depending on the time of year, the temperature and weather will influence your choice. For reasons I'm still unsure about, most of the contests in Australia are in the middle of summer, so wearing long sleeves, sunscreen and a hat is the starting point for your adventure. Sitting in the midday sun for any period of time, absent a breeze is not fun, so shade becomes a requirement, not a nice to have. Mind you, at least we don't need to contend with meters of snow, well, not where I am. In other words, what works for me might not work for you. Finding locations is tricky. You can drive around, consult satellite maps, look for desirable attributes and still be rudely surprised when you get to the point of turning on your gear. One of the best lessons I learnt was operating from my car during a contest that awarded points for operating in as many different locations as possible. I used a satellite map to find a location within each boundary and then drove from point to point. If I recall, I set-up in over 30 locations across a 48 hour period. It taught me a great deal about discovering high voltage power lines on a satellite map, the impact of trains on your HF radio, the difference that geology has on your antenna and what a safe location looks like and what the typical hallmarks are for a scary one. My most recent discovery tool is a public toilet map. It's not perfect, the user interface is horrid and for some reason it needs to navigate from the Timor Sea to each toilet, but those issues aside, it does help eliminate locations that lack facilities. I am in the process of cross referencing the Parks On The Air map with the Toilet map to see if there are some nearby parks that have shade, a loo and the opportunity to park nearby to reduce the amount of lugging required for the gear we intend to bring to the next field day. So, what are your tips for finding a place to operate? What kinds of things have you learnt that influence what choices you make? Before I go, one pro-tip. Keep a record of where you actually operate and whilst you're at it, what you used, and not. You can thank me later. I'm Onno VK6FLAB

Foundations of Amateur Radio Have you ever had a day when nothing you started actually got anywhere? I've had a fortnight like that. Several weeks ago I wrote a couple of articles about emergency communications and its tenuous relationship with our hobby. As a result I managed to get a week ahead of myself and started using that week to do some long overdue analysis of the WSPR or Weak Signal Propagation Reporter data set. I've started this process several times and I finally had a whole fortnight to come to grips with 6.7 billion rows of data. Spoiler alert, it hasn't happened yet. The data contains a record of every reception report uploaded to WSPRnet.org since Tuesday 11 March 2008 at 22:02 UTC. It's published in compressed comma separated value text files and after previously spending weeks of wrangling I managed to convert each one into an sqlite3 database. This wrangling was required because some amateurs used commas in their callsigns or grid squares, or backslashes, or both, and SQLite import isn't smart enough to deal with this. After doing this conversion, I could actually query 191 different databases. I could collect the results and three weeks later I'd have an answer, just in time to download the next month of data. Garth VK2TTY suggested that I look into parquet as an alternative. No joke, This Changed My Life. I managed to convert all the compressed CSV files to parquet, a process that took a day, rather than a week with SQLite, and then I could start playing. If you're going to do this yourself, make sure you have a big empty hard disk. After a few false starts, the report that previously took three weeks, returned in three hours, and if we're getting technical, since I know this will make at least somebody laugh, the parquet files are stored on a USB drive connected to an iMac that has the directory mounted via sshfs to a virtual Linux desktop machine that's running the duckdb binary inside a Docker container running on a different virtual Docker machine. If you're keeping track, the database travels across USB via two SSHFS mounts to duckdb and it still only takes three hours. So, impressed doesn't even begin to describe my elation. If you're asking "why?" - the answer is that I don't run untrusted binary executables on my host machine. This allowed me to start doing what-if queries when I discovered a fun issue. A chart I generated with minimum, average and maximum power levels over time showed that there was at least one station that was claiming that it was transmitting with 103 dBm. For context, that's multiple times the power of HAARP, the High-frequency Active Auroral Research Program which in 2012 was the most powerful shortwave station using "only" 95.5 dBm, or 3,600 kilowatts, and only 2 dBm shy of the 105 dBm or 32 megawatts used by AN/FPS-85, part of the US Space Force's Space Surveillance Network, able to track a basketball-sized object 41,000 km from Earth. In other words, 103 dBm is less of a whisper and more of a roar. Funnily enough, not every receiver on the planet reported these transmissions, but more than one did, so the issue is at the transmitter. Unfortunately, when I started looking for reports using more than 60 dBm, there were plenty to choose from, over 18 thousand. While that's less than 0.0003%, it made me wonder how much of the data is dirty and what should I do about it? There's other examples of dirty data. My beacon has been reported on 24 MHz, which is odd, since my licence conditions do not permit me to use that band. Odder still is that several other beacons, normally on 28 MHz like me, were also reported on 24 MHz by the same station. How often does that happen? I've previously reported the missing data from the hybrid solar eclipse in 2023, just under two hours and 12 minutes before the eclipse and the 38 minutes following it was missing. I've not yet checked to see if it magically reappeared. Then there's the faulty decodes. I've talked about this before. Different WSPR versions are better or worse at decoding and the point at which it breaks down varies. In other words, some decoded data is inevitably wrong. I have previously charted activated grid squares. Apparently, all of Earth, yes, all of it, has at one time or another been used both as a transmission or reception site. Including point Nemo, the top of Mount Everest, all of the arctic and antarctic and plenty more out of the way places, like say the Surveyor Generals Corner located in the Ngaanyatjarraku shire - look it up. Interesting patterns emerge when you split activations down per band. It's not clear if those are decoding artefacts or man made claims. I've asked the HamSci community for guidance, since dropping incorrect data on the floor doesn't seem to be the right way to go about things, and whilst correcting data seems obvious, what do you change it to and how do you know what's correct? So, no progress to show for two weeks of work and barely enough to whet your appetite to get on

Foundations of Amateur Radio A few weeks ago I discovered that the regulations for amateur radio in Australia had some definitions that caused me to wonder if 2,312 amateurs in VK, me among them, had been operating illegally? Specifically it appeared that using a WSPR or Weak Signal Propagation Reporter transmitter of any kind, both computer controlled and stand-alone beacons, was contrary to what was permitted in the rules, since in Australia an "amateur beacon station" means a station in the amateur service that is used principally for the purpose of identifying propagation conditions. The rules go on to say that you must have a specific beacon license and not having one is not permitted. I suggested that it was time to send a letter to the regulator, seeking clarification. Well, let me tell you, that set a cat among the pigeons, not at the regulator, but within the amateur community. Between posting a draft of my proposed email to a local mailing list before sending it to the regulator, and publishing my article, I received responses that ranged from "let sleeping dogs lie", "you are now on their radar", "you will be prosecuted because you admitted to breaking the rules", "carry on and ignore the rules because I am", and plenty more in that same vein. There were two amateurs that indicated curiosity about what the response might be while pointing out that none of this was legally binding since it hadn't been tested in court. I also discussed the matter on my weekly net and I learnt that DMR hotspots come in a duplex version, meaning that what you transmit into the hotspot is also transmitted by the hotspot on RF whilst sending it to the Internet. If you've been paying attention, you'll notice that this fits the definition of an "amateur repeater station", which also requires a specific license. I received a prompt reply from the Australian Communications and Media Authority, the ACMA, the Australian regulator. Here's what the regulator had to say in response to my query: "I can confirm that you can continue to operate your WSPR beacon and Duplex Hotspot as described without requiring an Amateur Beacon or repeater licence." It goes on the say: "Operation of these types of amateur equipment is permitted under the current amateur non assigned arrangements and as such will continue to be permitted under the class licence arrangements." As a result, if you've been listening to WSPR on 10m, you'll have discovered that my 10 dBm beacon went back on the air 45 minutes after receiving this information. The letter confirms that both WSPR and Duplex hotspots have previously been, and will continue to be, allowed under the new rules from the 19th of February 2024 when they come into effect. The final paragraph from the regulator sets out the boundaries of where the rules apply. It says: "The definitions in the Interpretation Determination are broad definitions of amateur repeaters and beacons. For the purposes of amateur licensing the ACMA only considers apparatus assigned licence services, where individual frequency coordination is carried out and specific licences are issued, to be amateur repeaters and beacons." In my opinion this is significant because you only need to apply for a separate amateur beacon or repeater license in very specific circumstances related to frequency coordination. It makes me wonder if the local beacon operators require an ongoing license for all of their beacons or not. What I learnt from this process is that there is a high level of fear in the amateur community towards the regulator. I do not know where this originates, since I've interacted with the regulator on dozens of occasions since obtaining my amateur license in 2010 and in every case the response was courteous and informative. When the response wasn't what I expected I replied asking for extra clarification and received it. This enquiry was no different. Going back through decades of old publications I've previously seen letters between the community and the regulator and I have yet to see anything that warrants the level of fear that appears to permeate our community. So, why are we afraid of the regulator and why do we keep spreading that fear to anyone within propagation range? What have they ever done to you? I'm Onno VK6FLAB

Foundations of Amateur Radio I recently discussed some of the notions of amateur radio as emergency response. The idea that you might jump into the breach and be a hero is appealing and often celebrated. The American Radio Relay League, or ARRL, proudly tells the story of two amateur radio emergency communication events. One, of a person who fell in their bathroom and happened to have a handheld radio that they used to contact another amateur who contacted emergency services. The story goes on to say that being part of the Amateur Radio Emergency Services or ARES had taught the amateurs the ITU phonetic alphabet, as-if that's not a requirement for getting your amateur license. Then there's the story of two teenagers who were critically injured in a remote area and amateur radio rescued them due to a contact with a random local amateur. Never mind that there was a local off-duty EMT who actually stabilised the patients. While you might point at this as "amateur radio to the rescue", to me this is a case of people attempting to make the story about amateur radio. If the person in the bathroom happened to have a mobile phone nearby, the story would not have even made the nightly news and if the people in the remote area had actually prepared properly, they'd have had an emergency position-indicating radiobeacon or EPIRB and a satellite phone, rather than accidentally bumping into a random radio amateur. Moving on. Have you ever noticed that your mobile phone stops working after a couple of hours during a power outage? It's because mobile phone towers run on batteries that depending on load might last up to 12 hours, often much less than that, anywhere from down when the power goes out to 3 hours until the batteries fail. Note that I'm not talking about the battery in your phone, I'm talking about the ones in the tower serving your phone. I mentioned previously that there was a network outage affecting 40% of the Australian population. The get-out-of jail card was that the rest of the population still had mobile, landline and internet connectivity. What would happen if the other network operator also went down? Is there a place for amateur radio in those scenarios? Let's explore. If all mobile, telephone and internet networks were down, what would that look like? Could you call an ambulance or the fire department using amateur radio? Who would you talk to, on what frequency and on which radio would they be listening? Would you set up your portable shack in the local hospital or fire station? Would ambulances and fire services be able to coordinate during such an outage, or would you have your local amateur club ride-along on every ambulance and fire truck? What does such a system look like in actuality? Has there been any planning or training for this? Are there refresher courses and special certifications? Does your local community have anything like this in place, or are you starting from scratch? During widespread and long lasting fire emergencies in Australia, radio amateurs have acted as emergency services radio operators. There is at least one amateur club where, years ago, the members underwent special training with the local State Emergency Services to learn their language and procedures, just in case it becomes short staffed when an actual emergency occurs. I've often said that doing contests is a good way to learn how best to operate your station and how to work in adverse environments with lots of interference, man-made or otherwise. The reality is that it's more likely than not that you'll be using a line-of-sight FM radio in the emergency services communications bunker than sitting in the rubble of your shack using HF with a wire antenna running off battery trying to get someone, anyone, to help you and your community. There are official amateur radio emergency organisations, WICEN in Australia, ARES and RACES in the United States. Much is made by these organisations about joining and training, but very little in the way of actual emergency response. Is that a marketing issue, or are these types of organisations obsolete and waiting to be disbanded? My point is this. If amateur radio is really a service as the WIA states, "A Trusted Partner in Emergency Response", or as the ARRL puts it, "When All Else Fails", even making that a registered trademark, where is the evidence of their activity, where are the annual reports, the after action lessons learnt, the inter-team competitions, the talks at local clubs, the league tables of emergencies handled, lives saved and babies born? To give you insight into just how broken this is, any licensed amateur can become a member of ARES, but you can only read their newsletter if you're a member of the ARRL. In Australia, for a while, the WIA offered a course for Public Safety Training for Radio Amateurs, but only to amateurs with an Advanced license, which I discovered after spending $633.92 to print out, collate and bind the 973 pages of course material, as-if

Foundations of Amateur Radio Amateur radio is an activity that falls between two camps, those who think of it as a service and those who approach it as a hobby. I think that the notion of amateur radio as a service is often repeated, but in my time as part of this community, I've seen little evidence of actual service. That said, the idea of amateur radio as a service is often linked to emergency communications, for example, a phrase used by the Wireless Institute of Australia is "Amateur Radio - A Trusted Partner in Emergency Response" on a page outlining the long and fabled history of our hobby in service to the community in times of emergency, mind you, none of them in the past decade. If we look at the idea of amateur radio as an emergency response, what does that look like today and how might we best be of service? The question that prompted this discussion centred around the best mode to use for emergency communications and was presented in the context of a tool that links HF radio with email, but is that really the best way to communicate in an emergency? I mean, picture this, you're on a boat in the middle of the ocean, it's the small hours of the morning, you're asleep, and your boat just sailed into a submerged container and now you're sinking, so the first thing you do is, fire up your laptop, your radio, and link the two to send an email over HF to get help? Alternatively, your community has just been hit by a natural disaster and the power grid went down, and the first thing you do is use as much battery hungry complex technology as possible to get the word out? So, until we can send email or a short message directly from our amateur radio transceiver, and I have no doubt that some bright spark is working on that, there are better ways to make contact in case of an emergency. From a mode perspective, at the bottom of the pile is Morse code. I say bottom, not because it's a poor way of communicating, but it doesn't require much in order to get working. You could essentially use a car battery and splatter your emergency communications around. One downside is that you'd need to learn Morse code and while you're in the middle of an emergency is probably not the best time. If you're on a sinking boat in the middle of the ocean, you're likely going to use a HF radio, or an emergency beacon, or even a satellite phone, but if you're on land, dry or not, and if you're not an amateur, your best bet is to find a 27 MHz AM Citizen's Band radio, so you can make enough noise to have people come and find you. The reality, more likely than not, is that emergency services are outside the danger zone waiting for authorities to permit entry. It should be clear by now that there are several levels of emergency communications before we get to amateur radio. That said, if you have an amateur radio, then you're likely going to use voice communications over SSB on HF or FM on VHF or UHF. Now you might ask about communications going the other way, from outside the emergency zone, where power and sunshine are plentiful, where you can use a computer without issues. Only thing is that if it's all peaches, why are you attempting to link your radio to HF when on the balance of probability there's a mobile phone sitting in your pocket? A couple of months ago there was a 12 hour network outage at one of the two main telephone networks affecting nearly 40% of the population of Australia. It was recently revealed that during that time almost 2,700 people could not call emergency services on either their mobile or land-line, let alone use the Internet. You could argue that this is an actual emergency, but is amateur radio really the vehicle for making contact? I mean, you're trying to call emergency services, your phone isn't working, so rather than use a telephone on another network, you go and find your nearest radio amateur and ask them to call for an ambulance, on their HF radio? Where does this leave us? In my opinion, the notion that your shack is going to be used for emergency response is fanciful. That's not to say that there isn't a place for radio amateurs. Far from it. If you really want to be of service, learn how to operate your radio well, make a plan to work through if you hear a distress call while you monitor emergency HF frequencies, visit the local emergency services to see if they offer training for radio amateurs and make yourself available in case of emergency and you're more likely to be of service than if you sat in your shack polishing your valves. If you're so inclined, planning for the next emergency, start asking questions. Find out what the plans are for your emergency AM broadcast network, learn how things might break and perhaps then you might consider amateur radio as a service to the community, just not in the way you might have thought. Next time I'll explore the reality of amateur radio as an emergency response. I'm Onno VK6FLAB

Foundations of Amateur Radio The other day I came across an amateur who expressed concern that someone was using a frequency set aside for repeater use with their hotspot. Band plan issues aside, and you are encouraged to send an email to [email protected] with the link to the official band plan that applies to your DX entity, in my experience it's not unusual for an amateur who is configuring their so-called hotspot to use such a frequency. While you might be familiar with the concept of a mobile phone hotspot that allows you to connect a computer through your phone to the Internet, in this case we're talking about an amateur radio hotspot. Similar in that it allows you to connect through the device to the Internet, but different in that this is essentially a device that connects radios to the Internet, and yes, if we're being pedantic then computers and mobile phones also have radio, well spotted. Anyway, an amateur radio hotspot is a radio with an Internet connection and in that it's much like a modern repeater. Often they use low transmit power, have limited range within a building or vehicle and because of that are hardly "unattended". That said, if you connect a more effective antenna and an amplifier, you could make such a device into a full blown repeater. In other words, the line between hotspot and repeater is likely in the eye of the beholder. Given that the regulator in many countries requires a license for operating a repeater, or a beacon, I wondered what the official definition of a repeater was, so I went looking. Note that this applies to Australia only, but you'll find the journey illuminating I'm sure. The current "Radiocommunications Licence Conditions (Apparatus Licence) Determination 2015" does not have either the word repeater or beacon. The new "Radiocommunications (Amateur Stations) Class Licence 2023" which comes into effect on the 19th of February 2024 uses both repeater and beacon several times but does not define what they are. It has an interpretation section with a note that lists both "amateur repeater station" and "amateur beacon station" and states that the regulator can define terms under section 64(1) of its own act. The "Australian Communications and Media Authority Act 2005" section 64(1) states that "The ACMA may make a written determination defining 1 or more expressions used in specified instruments, being instruments that are made by the ACMA under 1 or more specified laws of the Commonwealth." It should come as no surprise that neither repeater nor beacon appears in this document. I then thought to go sideways and search the "Register of Radiocommunications Licences" for a repeater license. It reveals a PDF for a license with all manner of detail, frequencies, power levels, location, antenna type, etc. for a license, but no definition of what a repeater is. I then looked at the 481 pages of the "Radiocommunications Act 1992". It uses both beacon and repeater. Unfortunately beacon is in relation to the operation of lighthouses, lightships, beacons or buoys. Repeater is in relation to two or more digital radio multiplex transmitters. I then searched through the "Federal Register of Legislation" for the phrase "amateur beacon station". It returns 27 results of which 9 are in force. I downloaded all 9, including any explanatory text if it was available. In all, 340 pages of legal documents. Finally we have progress. In the "Radiocommunications (Interpretation) Determination 2015" we find the following definitions: "amateur beacon station" means a station in the amateur service that is used principally for the purpose of identifying propagation conditions. "amateur repeater station" means a station established at a fixed location: (a) for the reception of radio signals from amateur stations; and (b) for the automatic retransmission of those signals by radio. So, if your hotspot is in a vehicle it's not a repeater, but if you have it sitting in your shack, it is. Similarly, apparently, my 10 dBm WSPR transmitter, which I use solely for the purpose of identifying propagation conditions, is a beacon. Apparently if you have your computer controlling your radio using WSPR, that's a beacon too. You can apparently apply for a license and pay the regulator for the privilege, the price of which went up by 510% according to their own documentation from $29 to $177, no idea if that's a once off or an annual charge. So, now we have a situation where, apparently, the rules state that I'm not permitted to use WSPR without a beacon license. In fact, the "Explanatory Statement to the amateur class licensing reform instruments" explicitly states that "Subsection 13(2) prohibits the operation of an amateur station for specified purposes, including for the purpose of obtaining a financial gain or reward. The subsection also prohibits the operation of an amateur beacon station or an amateur repeater station under the Amateur Stations Class Licence, and, subject to subsection (3), the transmis

Foundations of Amateur Radio From the 19th of February 2024, the ACMA, the Australian Communications and Media Authority, the regulator, is modifying the rules for amateur radio in Australia by moving to an amateur class license where all amateurs will operate under the same license instead of under an individual one. You must be qualified to operate under the new class license and all currently licensed radio amateurs should now have been issued with a recognition certificate for their current qualification level. Keep this certificate safe, it authorises you to operate as an amateur and shows which callsigns you currently hold. I've just received a revision that now correctly identifies my callsign VK6FLAB as a four-letter callsign, rather than three-letters which caused concern over the longevity of my call. There's no annual charge to operate as an amateur, no charge to keep a callsign, and no charge to do an exam, however, if you operate a repeater or beacon, you'll continue to require a transmitter license. There are once-off charges for applications to consider and issue recognition certificates and callsigns but those are not new. The document that legally defines amateur radio in Australia, colloquially the LCD, is replaced by the Radiocommunications (Amateur Stations) Class Licence 2023. The regulator carefully states that: "To operate an amateur station under the amateur class licence, you must comply with the conditions within it", but doesn't clarify if those conditions have changed or not. External commentary claims they haven't, but it was completely re-written and it's difficult to compare the precise actual wording side-by-side. This has happened before, for example, when the regulator introduced the Limited license in 1954, the Novice license in 1975, abolished Morse in 2004, and introduced the Foundation, Standard and Advanced licenses in 2005. It was replaced again in 2015 and has been revised since, most recently on the 17th of November 2021. I suspect lawyers will find potentially unintended but material differences between documents, but to my knowledge, that investigation has not yet occurred. I think this is a perfect example of where the peak bodies claiming to represent amateur radio in Australia have a responsibility. There are many rules around the who, how and where to conduct a qualification exam. For example, the regulator has decided that online or residential exams are not permitted, leaving venues, printed exams and postal delivery as an ongoing cost and concern. There are plenty of questions left. An amateur at Advanced level can hold a club station callsign but it appears that at a Foundation or Standard level you can no longer hold a club station license like VK6BSG and VK7HSD. You still need to log usage of a remote club station. Describing the requirements the regulator uses both "revise their arrangements" and "current arrangements will be retained" in the same paragraph, apparently contradicting itself. The regulator will ask you every five years if you want to keep your callsign. This infers a system to contact you. What does that look like, how will it be maintained, are there requirements for keeping it current, does it need to have the location of your station, an email address, or just any means of contacting you, and is it public? The official register of radio communication licenses will no longer hold amateur licenses so it's unclear how you'll be able to contact another amateur, or how we'll be able to know who holds which callsigns at what level in which location and when a reminder is due. The details around the new callsign register are incomplete to say the least. What does breaking the rules look like? With individual amateur licenses your ability to operate is directly linked to you and if found in breach, your license can be cancelled. Under a class license, your ability to operate hinges on knowledge that cannot be taken away. The regulator publishes the relationship between some international amateur licenses and qualification levels in Australia and as an international visitor you can apparently operate in Australia for 365 days if your current license is recognised. After that, unless you hold a Harmonised Amateur Radio Examination Certificate or HAREC, you need to apply for a recognition certificate after either paying for recognised prior learning or passing an exam, even though you were already automatically recognised as having the appropriate qualifications when you entered the country. Does the list of recognised licenses get longer as more international amateurs pay for prior learning and if you leave the country and return, will the clock reset? There's more. For example, the date that you got your US Technician license determines your recognition. Before 23 September 2016 you're recognised at an Australian Advanced level, after that at a Foundation level. And finally, if I were an accredited unpaid volunteer assessor, authorised to admin

Foundations of Amateur Radio The other day I stumbled on a project called Maia SDR by Daniel EA4GPZ. Maia, spelled Mike Alpha India Alpha, is a star in the Pleiades cluster. The Maia SDR project homepage proclaims that it is "An open-source FPGA-based SDR project focusing on the ADALM Pluto". Now, I can completely understand if that collection of words is gibberish to you, but take it from me, it's not, let me explain. PlutoSDR or Pluto is the common name of a piece of hardware which is officially called the ADALM-PLUTO Evaluation Board. It's a sophisticated device made by Analog Devices that provides a radio platform with some very interesting properties. Specifically it's both a radio transmitter and receiver with the ability to use frequencies between 70 MHz and 6 GHz. It runs embedded software you can tinker with because it's all Open Source and it's all very well documented. Many people have used the Pluto as a remote transceiver by controlling the on-board radio with a USB cable. While that's neat, it's not what I have been wanting to do for a number of reasons. The Pluto has the ability to sample data at a rate of 61.44 mega samples per second or MSPS. That translates to a bandwidth of 56 MHz. A typical amateur radio has a bandwidth of 2.5 kHz. This bandwidth comes at a price. For starters, USB on the Pluto isn't fast enough to handle 56 MHz of data, so if you're using it as a remote radio over USB, you need to lower your expectations. However, the hardware itself can process data at that rate, as long as it stays inside the radio. So, if you had a way to process data inside the radio and a way to show what you did with the data across USB, you could use all of the 56 MHz at once. The Maia SDR project does exactly that. It processes the data and presents it to the world as a waterfall image, like the one you might have seen in WSJT-X, fldigi or SDR++. If you've seen the voice version of my podcast on YouTube, you'll also have seen a waterfall. It's an image that scrolls vertically, showing frequencies left to right, and signal strength by colour, traditionally, a rainbow that uses blue for low power and red for high power. Every time period the image scrolls adding another row representing the radio spectrum at that time. It's a very useful way to show massive amounts of radio spectrum data in close to real-time. The waterfall that WSJT-X produces is about 2.5 kHz wide. The waterfall that Maia SDR produces is 56 MHz wide. To give you some context, the entire HF spectrum, between 2200m and 6m easily fits within 56 MHz. Now, there's a wrinkle. As I said, the Pluto frequency range starts at 70 MHz, so that means we can't use it to listen to HF. Well, not without the help of another gadget, called a transverter. Essentially it moves a set of frequencies from one range to another. The gadget I have, a SpyVerter 2 HF Upconverter, translates anything between 1 kHz and 60 MHz and moves it to between 120 MHz and 180 MHz. If you combine the Pluto with Maia SDR and a SpyVerter, you can plug your antenna into the SpyVerter, connect that to the Pluto, connect to the Maia SDR website that's running on your Pluto, tune it to 120 MHz, and see 56 MHz of HF bandwidth scrolling past as fast or slow as you want. You'll find the 10m band at 148 MHz, the 15m band at 141 MHz and the 20m band at 134 MHz. Now if that's not cool enough for you, Maia SDR is as I said Open Source. This means that the project publishes all of the code that makes this happen. The Pluto comes with a number of devices on-board that process information. At the antenna end is an AD9363, essentially a chip that converts RF into digital and back. The digital information is processed by a device called an FPGA, a Field Programmable Gate Array. Field Programmable means that mortals like you and I can change the software that it runs. Essentially an FPGA is a programmable circuit board used for information processing. To scratch the surface of what that means, you could for example program an FPGA to behave like a microprocessor, or you could use it to do accelerated matrix multiplications used for neural networks like you can with a graphics chip, or in this case, a device that does all of the digital signal processing. Finally the Pluto has a dual core ARM processor. You'll find those inside most Android phones and Raspberry Pi's to name a few. It's used to extract data from the FPGA and present it on a web page. Oh, and there's a progressive web app for your phone, so you can see this waterfall on your mobile phone if you want. So, thank you to Daniel EA4GPZ for sharing your project, it's very much appreciated! There are some caveats. The Pluto is easily overwhelmed by strong signals, so you probably need filters. I'm using a wide 2m band pass filter between the SpyVerter and the Pluto, just so that my local WiFi network doesn't overwhelm the whole thing. You're receiving between 0 and 56 MHz, so you'll need an appropriate antenna. The frequency respon

Foundations of Amateur Radio The attraction to amateur radio for me lies in the idea that it provides a framework for experimentation and learning. There's never an end to either. Each time you go on-air is an opportunity to do both and every chance I get, I cannot help being sucked into another adventure. My weekly scribbles are an attempt to both document what I've been up to and to encourage others to take a step on the path that I'm discovering, moment by moment, week by week. One of the more, lets call it, comment inducing, activities I like to explore is low power operation. This is not to the liking of many operators who are happy to run their shack at full legal power. For me, full legal power is 40 dBm, or 10 Watts. That's not to say that I've never experienced the thrill of running a pile-up on a contest station, I have. What's not to like? You speak with people from communities far-and-wide, they're clamouring to talk to you and making contact is pretty easy, almost effortless. The lure towards more power, bigger antennas, more bands and more radio is always there, but it's not all there is to this hobby. My year-long efforts of running a 10 dBm, or 10 mW, Weak Signal Propagation Reporter, or WSPR, beacon, is evidence that you can make it 13,945 km from me in VK6 to PA where it was heard by Jaap, PA0O in Zuidwolder, just outside Groningen in the North East of 't kikkerland. In fact, across 2023, my 10 dBm beacon was reported 4,849 times by 58 stations, many inside Australia, but there were reports from Indonesia, Japan, New Zealand, Taiwan, Antarctica, Sweden, and as I said, the Netherlands. One of my friends, Charles NK8O, is a mostly mobile operator who loves to set up for both Parks On The Air, also known as POTA, as well as World Wide Flora and Fauna, WWFF. His chosen mode is CW, but you'll find him using digital modes like FT8 and even as a rare DX event you might strike it lucky and hear his voice. Most of his activity uses batteries, so you'll rarely make contact with him when he's using more than 47 dBm or 50 Watts. A couple of weeks ago during the weekly F-troop net he announced that for the duration of 2024, Charles intends to operate using low power, or QRP. Operating QRP isn't for everyone, but I'd hazard a guess that if tried, there's plenty to learn and experience by dialling the power down to play in a low power environment. Think of it like this. If you're into cars, it's the thrill of driving fast. It's not the only way to drive and enjoy yourself. Driving sedately, touring the back roads, will get you to your destination just as well and along the way you'll have the opportunity to look out the window, to even have the window down and to enjoy the environment, rather than spending every second being on a hair trigger. If fishing is more your thing, high power radio is like dynamite fishing. You'll easily catch all the fish in the pond, but once you have, there's nothing left to do. Fly fishing on the other hand gets you a different but perhaps just as satisfying experience. So, if you've never done this QRP thing, what can you expect when you turn the power down? First of all, reception works just the same. So, everyone you heard before will continue to be heard. Transmission is going to be a little different. If you've ever changed over radios you might already have experienced the jolt between what you can hear and what you can work which can differ significantly between two radios. If you're used to high power operation, you'll essentially work most stations you can hear, but when you're using low power, there's going to be stations that you have little or no chance to work. Most of those are obvious so-called alligators, all mouth, no ears. That said, plenty of loud stations have years of honing their skill and station and your QRP call can just as easily be heard as the next station. You'll likely sharpen your calling skills. There's no point in calling when other stations are blotting out your call, so you become adept at dancing around other signals. You'll spend more time considering propagation and the best band to make your signal count. Another side effect you'll likely notice is less wear and tear on your gear. There's also little chance of having RF inside your shack upsetting your computer, or getting complaints from the neighbours who happen to have a crappy TV that stops working as soon as you key up. If you make mistakes, your station is more forgiving and less likely to be damaged when an unexpected fault occurs. Speaking of faults. The other day a coax switch in my shack caused my radio to stop transmitting. Luckily with the power setting at its lowest, there was no permanent damage. After testing with a multimeter I discovered that it shorted the centre pin to shield in one position. When I opened up the switch, I discovered that the blade that gets moved between ports had become slightly twisted, which in turn caused it to ground against the body. A slight t

Foundations of Amateur Radio Today I'm going to spend a little longer with you than usual, but then, I think this is important and it's good to end the year on a bang. Have you ever attempted to make contact with a specific DXCC entity and spent some time exploring the band plan to discover what the best frequency might be to achieve that? If you got right into it, you might have gone so far as to attempt to locate the band plan that applies to your particular target. If you have, what I'm about to discuss will not come as a surprise. If not, strap yourself in. When you get your license you're hopefully presented with a current band plan that is relevant to your license conditions. It shows what frequencies are available to you, which modes you can use where, and what power levels and bandwidth are permitted. It should also show you if you're the primary user or not on a particular band. If you're not sure what that means, some frequency ranges are allocated to multiple users and amateur radio as one such user is expected to share. If you're a primary user you have priority, but if you're not, you need to give way to other traffic. It should come as no surprise that this is heavily regulated but as a surprise to some, it changes regularly. Across the world, frequency allocation is coordinated by the International Telecommunications Union, the ITU, and specifically for amateur radio, by the International Amateur Radio Union, the IARU. It coordinates frequencies with each peak amateur radio body. The ITU divides the world into three regions, Region 1, 2 and 3, each with its own band plan. Within each region, a country has the ability to allocate frequencies as it sees fit - presumably as long as it complies with the ITU requirements. As a result, there's not one single picture of how frequencies are allocated. And this is where the fun starts. In Australia there's an official legislated band plan, cunningly titled F2021L00617. It contains the frequencies for all the radio spectrum users as well as a column for each ITU region. The document is 200 pages long, and comes with an astounding array of footnotes and exclusions. It's dated 21 May 2021. There's a simplified version published by the Wireless Institute of Australia, which comes as a 32 page PDF. It was last updated in September 2020. When I say "simplified", I'm of course kidding. It doesn't include the 60m band which according to the regulator is actually an amateur band today. The 13cm band according to the WIA shows a gap between 2302 and 2400, where the regulator shows it as a continuous allocation between 2300 and 2450 MHz. The point being, who's right? What can you actually use? Oh, the WIA does have a different page that shows that 6m "has had some additions", but they haven't bothered to update their actual band plan. To make life easier, the regulator includes helpful footnotes like "AUS87". This is particularly useful if you want to search their PDF to determine what this actually says, since it only appears 156 times and it's not a link within the document. In case you're curious, it's related to three radio astronomy facilities operated by the Commonwealth Scientific and Industrial Research Organisation, better known as the CSIRO, two by the University of Tasmania and one by the Canberra Deep Space Network. Interestingly the Australian Square Kilometer Array and the Murchison Widefield Array don't feature in those particular exclusions, they're covered by footnote AUS103. If that wasn't enough. The regulator has no time for specific amateur use. You can find the word Amateur 204 times but there's no differentiation between the different classes of license which means that you need to go back to the WIA document to figure out which license class is allowed where, which of course means that you end up in no-mans land if you want to discover who is permitted to transmit on 2350 MHz. If we look further afield, in the USA the ARRL publishes half a dozen different versions, each with different colours, since black and white, grey scale, colour and web-colour are all important attributes to differentiate an official document. Of course, those versions are now all six years out of date, having been revised on the 22nd of September 2017. The most recent version, in a completely different format, only in one colour, has all the relevant information. It shows a revised date of 10 February 2023, that or, 2 October 2023 because of course nobody outside the US is ever going to want to refer to that document - seeing as there's only amateurs in the USA, well at least according to the ARRL. Interestingly the US Department of Commerce, the National Telecommunications and Information Administration, Office of Spectrum Management publishes a colourful chart showing the radio spectrum between 3 kHz and 300 GHz. You can't use it as a technical document, but it's pretty on a wall to amaze your non-amateur friends. The FCC has a band plan page, but I couldn't disc

Foundations of Amateur Radio Walking into your shack is often a joyous experience. You take a moment to smile at your setup and, at least mentally, rub your hands in glee anticipating some fun. Well, that is how it is for me, but recently it's been less of that and more of an audible groan at the accumulated cruft that makes it nigh on impossible to sit down, let alone achieve anything fun. It's not as bad as it could be. I'm forced to keep my station at least operational to host my weekly net, but if that wasn't there, it would have been overtaken by anything and everything finding a flat surface to put stuff on. It got to the point where I had to move some radio equipment off my desk, just so I could pile more stuff onto it. So, on Tuesday I finally had enough. It was a pretty normal day, waiting for others to get stuff done, deadlines be damned, but I took one look at the shack and snapped. This has happened before and I suspect that it will continue to happen throughout my life, but that day I'd crossed the line. Before I share what I achieved, I should mention a couple of other things. If you've been here for a while you'll know that I am an unashamed computer geek. Software Defined Radio, or SDR, appears to have been invented just for me, embedded computers, digital modes, networking, data analytics, Linux, Docker, you name it, I'm there. Mind you, this isn't new. It's been true for nearly forty years now, ever since I set foot into my high-school computer lab where I found myself looking at a bank of Apple 2 computers. Then I bought the first computer in my class, a Commodore VIC 20. Life was never quite the same. This to tell you just how much computing features in my day-to-day. I have a long term plan to use embedded computers like for example a Raspberry Pi to essentially turn my analogue Yaesu FT-857d into a networked SDR. The idea being that I use my main computer to do the processing and the Pi to control the radio and feed the audio in and out across the network. I want to make it so that you can use any traditional SDR tool with such a radio, and if I get it right, any other radio. For more context, I'm getting more and more deaf. I swear my SO is speaking softer each day and hearing tests tell me that audio above 2 kHz is pretty much gone. I have been playing with audio signal processing with a view to tailoring the audio coming from my radio into something more audible to me. On Tuesday I had an ah-ha moment. I could keep waiting until I got all that done and then set-up my shack just so, or I could embrace the analogue nature of my gear and use the mixing desk I have to feed the audio through its on-board audio processing and at least improve my audio experience today, rather than some nebulous future time. Finally, I purchased a peg board some time ago for the specific purpose of strapping my coax switches to so I would not have to contend with coax all over my desk whilst trying to remember which switch did what when I finally had a moment to play. All this came together in a new version of my shack, albeit an alpha pre-release, to be treated with extreme caution, if you break it, you get to keep both parts and it will kill a kitten without notice. To get started, I removed all non-radio stuff from my desk. Including half a dozen computers, a dozen patch leads and adaptors left over from the harmonics testing project, there were monitor cables, USB cables, a variety of power supplies and a stray binder with empty pages. I found all the radio gear that I really wanted to have on my desk, placed it where I could actually use it and figured out how to connect the audio output from each radio to the mixing desk which also found a home. Then I jumped on the RF side of things. Getting started was the hardest part. I decided that it would make sense to split the peg board in two, one half for HF, the other for VHF and UHF. I have two coax switches that I use as the entry point onto the board. They're each fed with the antenna coax and each have one port connected to the other. The idea being that during a thunderstorm I can connect the two antennas to each other and isolate the rest of the shack. It won't protect against an actual direct hit, but all charge being built up should dissipate between the two antennas. Feel free to give me suggestions on how better to do this in a shack located on the second floor of a house in Australia. Note that the rules for grounding across the world are drastically different, so don't assume that your laws apply in Australia. The HF coax side has a strapped down Bias-T which powers the SG237 antenna coupler that's outside. Then there's a switch so I can connect HF to a radio or to a beacon, which I also strapped to the peg board. On the VHF side there's just a second coax switch to select between two radios, but only one is currently connected. I plan to strap my PlutoSDR to the other port. I powered everything up and couldn't trigger the local repeater. I go

Foundations of Amateur Radio Cars have been here for well over a century and so has radio. Cars pretty much start when Carl Benz first applied for a patent for his "vehicle powered by a gas engine" on the 29th of January 1886 which is regarded as the birth certificate for automobiles. Radio starts as a thing when Heinrich Hertz proves that radio waves exist in 1888. Since then things have changed, a lot. Today, both these technologies, cars and radio, are everywhere. It's estimated that there are 1.47 billion vehicles on the planet today, in contrast, there are only 44 thousand broadcasters across the globe, serving about 4 billion people, or half the population. So, cars win, right? Not so fast. The Wi-Fi Alliance estimates that there's 3.8 billion Wi-Fi devices being shipped this year alone and there's about 19.5 billion in use. Many of those are mobile phones, so they're not only using Wi-Fi, but GSM, CDMA, 3G, 4G or 5G radios. In many cases they'll have Bluetooth on board and will be receiving GPS information from the currently five constellations in orbit around Earth. Some will even have an FM receiver on board, just to cram another radio inside the same box. To give you a better sense of scale, 2022 saw 4.9 billion Bluetooth devices shipped. In 2010 it was estimated that there were a billion GPS users, today there are more than six billion users being served by GPS systems for positioning, navigation and precision timing. I haven't even talked about other uses of radio, like radar, astronomy, remote sensing, remote control, keyless entry and countless other related and interconnected technologies. So, while there's a car for every five or so people, there's at least two Wi-Fi radios per person and probably more like a dozen radios per person when you start counting those embedded in our daily lives. So, why is it that we have an estimated car enthusiast population of 10% and an estimated radio amateur population of 0.04%? It's not to do with the popularity of the topic. Google trends shows that both cars and radio are consistently trending downwards at about 2% each year since 2016. Radio is consistently twice as popular as cars. When you rank the global popularity of cars vs radio, out of 47 countries, 40 countries care more about radio than cars. South Africa and India care about cars 74% to 26% radio, even New Zealand, 56% vs 44%, cars to radio. At the other end of the scale, Peru, 2% cars, 98% radio. Germany, home for both Heinrich Hertz and Carl Benz, 92% radio, 8% cars. Popular search engines aside, there are other places to look for content. Take platforms like Prime Video, Netflix, Apple TV+ and YouTube. When you search for radio or cars on those platforms it's interesting to see what comes back and explore how relevant it is. I'll encourage you to do the experiment, but as a surprise to nobody, the results are universally woeful but illustrative. Searching for cars returns mostly relevant content, but a search for radio brings back results that have absolutely nothing to do with the topic. Seriously, on Netflix, two documentaries about Pele and Beckham, both famous footballers, neither known for their interaction with radio, rank higher than a documentary on Prime about radio astronomy, cunningly titled, wait for it: "Radio Astronomy". Even the initially promising Netflix result "Amateur" in response to the term "radio" is about a 14 year old basketball player navigating the dark side of sports. While we're at it, just for giggles, I checked the closed captioning for the movie and the word "radio" doesn't appear in the movie, at all. Speaking of representation, Netflix recently published their entire list of content for the first half of the year. The word radio appears exactly once, "John Mulaney: Kid Gorgeous at Radio City" and that doesn't even turn up as a search result when you go looking for "radio". The word "cars" appears 18 times in the Netflix library. So, why is it that topics like "radio", which is demonstrably twice as popular as "cars", and perhaps a dozen times more, let's call it, numerous, in society, has such a poor showing and what can we as connoisseurs on the topic of "radio" do about this? Cars are represented in a plethora of movies, series and shows featuring reviews, mods, restorations and entertainment. There's topic specific channels and social media. There's shops, events, races and so much car merchandise. Is that what's missing in radio, or more specifically, amateur radio, marketing, or is it something else? I'm keen to hear your thoughts. My email address is [email protected], get in touch. For my efforts, I'm publishing my podcast on YouTube and manually working my way through my back catalogue of over six hundred episodes, complete with a, YouTube imposed, limited five thousand character summary of the transcript, just to increase the chances of radio being a relevant search result when someone who's interested in our community comes looking. I'm Onno VK6FLAB

Foundations of Amateur Radio There is a perception in the community that the hobby of amateur radio is an expensive way to have fun. While it's entirely possible to spend thousands of dollars on equipment, in much the same way that it's possible if your preferred hobby is golf, getting started does not have to require that you start planting money trees. Lots of fun can be had using cheap amateur radio transceivers that are used all around the world. If you do start with such a radio, the chances are good that you'll come across amateurs who make disparaging remarks about the lack of compliance of such radios. When I say compliance, I'm talking about specific measurements specified by the International Telecommunications Union, the ITU. When you transmit on a specific frequency, there are rules about how much that signal is allowed to be unintended, or to use the official term, spurious emissions. Specifically, the signal you transmit has to meet the requirements for the mode you're using and it must also stay within limits on other frequencies. For example, if you have a 2m handheld radio that uses FM, the transmitter must stay within the required width for FM and it's not allowed to transmit above a certain level on any of the harmonic frequencies. When someone claims that all cheap radios are non-compliant, they're saying that such radios are either not transmitting a valid FM signal, or that the levels of the signal exceed the limits specified by the ITU. Given that such radios are in wide use, Randall VK6WR, Glynn VK6PAW and I got together to see if we could come up with something a little more scientific in the way of comment about such radios. With access to Randall's HP 8920A RF Communications Test Set we came up with a repeatable way to test a radio and then went to the local HAMfest where we subjected a pile of radios to our tests. In total we did 75 tests. Overall we tested 39 distinct models across 12 brands. So, what did we learn? All so-called "name brand" radios were fully compliant. All radios that were sold in Australia by Australian distributors were compliant. Baofeng radios made up the largest sample of inexpensive radios. Seven out of the 26 tested were compliant, eight were non-compliant and the rest, 11 were borderline. More on that shortly. We also tested many radios that had been purchased online. We didn't test enough of each model to make specific comments, but it's worth pointing out that half of all the online radios were compliant. Now, I mentioned borderline compliance. What we learnt was that there were some radios that fell within 6 dB of being compliant. The HP test set hasn't been calibrated for a while and we felt that allowing for a 3 dB random measurement error and a 3 dB systematic error would prevent us from marking a radio non-compliant when in fact it was. We categorised 16 radios as borderline. Our report is of course public. You can find it on my GitHub page as both a PDF and a markdown document. Whilst we were writing our report, we discovered uncorroborated suggestions that some radios might fail an emissions test after suffering unspecified damage in the output filtering stages. We looked at the schematic of one radio that suggests that a simple capacitor failure might cause a filter to fail without preventing the transmitter from operating. This might mean that a non-compliant transmitter might be made compliant again by replacing the faulty capacitor. We haven't tried and we don't know if a failed capacitor actually makes a radio non-compliant or not, or even if such a failure could occur and if-so, how. In other words, this might be a red-herring, we just don't know. One other comment worth pointing out is that it was suggested that some radios might use a specifically designed antenna to suppress the second harmonic. Given that some radios failed only on the second harmonic spurious emission requirement, but not the third, this seems plausible. All radios we tested had removable antennas and were tested without an antenna, since compliance relates to the transmitter, not the antenna. It does raise a more interesting question. What happens if you fit a different antenna to the radio? One adage that stands is that "you get what you pay for", but given the amount of cheap testing equipment available, it's relatively easy to test every handset in your shack. I'm Onno VK6FLAB

Foundations of Amateur Radio Amateur radio is an activity enjoyed by many people around the world. How many exactly is cause for debate. The most recent official figure we have is from the IARU, the International Amateur Radio Union. In 2020 it counted over 3 million people, but an article written a year later puts that figure at 1.75 million. In Australia there's a common narrative that the total amateur population is in undeniable decline, some think that it's on a stark decline. Interested in hard data, for years I've been collecting information around the amateur population in Australia and I can report that across the nine years that I have data for the total variation is within two percent and it's not a straight line down either. There was a dip in 2020, potentially associated with training and callsign allocation being moved from the Wireless Institute of Australia to the Australian Maritime College, something which is going to change again shortly when amateur licensing in Australia will revert to the regulator, the Australian Communications and Media Authority. If you're familiar with amateur licensing in Australia, that's not the only change, but that's not what I'm looking at today, mainly because the available information associated with the upcoming changes are limited at best, seemingly buried in invective at worst. Back to the topic at hand. One of the often heard responses in relation to the decline of our hobby is recruitment of new amateurs. It's a topic that I've spent plenty of time over the past decade contemplating. How do you share the joy of amateur radio with a general public who is apathetic to the preconceived ideas associated with this hobby, you know, old white men sitting in the dark with Morse keys. For the record, I prefer a shack with light and I still don't know how to use a Morse key, other than to make my radio beep. The rest is genetic. In the quest for spreading the word there's a repeated emphasis on the young, often coalescing around the annual Jamboree on the Air, or JOTA, as organised between Scouting groups and radio amateurs. I have previously said that JOTA was how I first came across amateur radio, but at the time, aged 15 or so, I had no money for such endeavours and the experience didn't resonate with me until decades later. So, you could argue that this is what changed me into an amateur, but the reality is that I had to come across the hobby a few more times before I got interested enough to investigate, something which I have spoken about before, in short, Meg, then VK6LUX introduced me to the concept of controlling a 2.4 GHz drone using higher power than was permitted with standard Wi-Fi equipment. I was hooked and got my license less than a month later. I then discovered that I needed more permissions and set about studying, only to get distracted with everything I could already do. I'm still being distracted today. So, JOTA is a potential touch point, but I see little evidence that the initial spark goes anywhere in a hurry. I'm not dismissing it as a way to have amateur radio gain relevance outside our own community, but perhaps there are other ways to make this happen. In the early days of my journey I attended country fairs with my club and we'd set-up a radio or six to show and tell. There was talk of doing this in a shopping centre, at the local hardware store and even brief discussions about doing this at the local electronics store. As enjoyable as this was, none of it ever appeared to generate any permanent interest and I don't recall seeing new amateurs suddenly appear at the club after any outings. Last week Glynn VK6PAW and I, set-up at the local airport, YPPH, that's Perth International Airport if you're not familiar with the designation allocated by the United Nations arm, ICAO or the International Civil Aviation Organization. Perth has a public viewing area. It's situated at the south western end of runway 03/21. It's an elevated position with minimal shade, some seating and you're 320 m from the runway centreline. It's a place where plane spotters congregate and now a few radio amateurs. One thing we have in common is an interest in radio. We were told that the plane spotters often listen to one or two frequencies and if they're into video, they might record one radio channel to include on their YouTube videos. When Glynn and I visited we had a few radios with us. When I say few, in amateur terms we only had about five or so, but I suppose that comes with the territory. As it happens, admittedly not by accident, our radios could receive airband frequencies, so we could tune to Perth Tower, Perth Arrival, Perth Ground, Perth Departure and Melbourne Central, all at the same time. Next time we'll likely bring some HF gear so we can also listen to HF aviation frequencies as well. While I was hosting F-troop, the weekly net for new and returning amateurs, midnight UTC, every Saturday morning for an hour, Glynn was busy talking and sharing with

Foundations of Amateur Radio For years I've been hosting a weekly net called F-troop. It's a one hour opportunity for new and returning amateurs to get together and share their questions, and sometimes answers, about anything and everything amateur radio, with side trips into astronomy, electronics, circuit boards, testing gear and whatever else takes our fancy on the day. The net runs for an hour every Saturday morning starting at midnight UTC, which for some is a time when they're fast asleep, though truth be told, several of our regulars are night owls. In VK6 where I am, midnight UTC is a more reasonable 8am, unless we have another referendum when we can decide if we want daylight saving, or not. So far we've had four of those, yes, really, in 1975, 1984, 1992, and 2009, and each time daylight saving or summer time was rejected. All I'm saying is that the chances are good that midnight UTC is going to be 8am in VK6 for a while yet. Anyway, that time of the morning affords me the luxury of getting out of bed at a sensible hour, having a shower, making a cup of coffee with my Significant Other, or SO, and ambling into my shack to get ready. It's a comfortable process, something I've done for over 12 years with very little in the way of variation with the exception of the 500th and 600th episodes which I hosted outdoors at a local radio club, complete with BBQ and many visitors. That and the Friday Night Technical Net with Reg VK6BQQ, but that's a story for another day. Last week a good friend, Glynn VK6PAW, asked me if I wanted to go out and have some fun, and having been pretty much cooped up for several years now, of course I said "yes". We're going to the viewing platform at the Perth International Airport, that's airport code YPPH, where I'll host the net in whatever way we figure out at the time. It's not an event, we haven't told anyone about it, and telling you now won't ruin the surprise for anyone, since this weekly rambling hits the airwaves after F-troop concludes. I knew there was a reason. Anyway, at this point you have every right to ask me, "Onno, why should I care?" Indulge me and let me see if I can explain. Most, if not all, of my amateur radio activities are planned. From time-to-time I might get in my car and drive to a nearby park and get on HF, but truth be told, I haven't done that for several years. I have regularly told you about contests I've done, often whilst operating portable, often with friends, but sometimes alone. I have activated all manner of things, climbed summits, played in parks, gone to lighthouses and other such places. Every, single, time, those activities were planned, often to within an inch of their life. What should I bring? Where am I going to set-up? What gear do I need? What spares are required? What logging tool is needed? Will I need food and water? You know, a typical 7p activity, Proper Planning and Preparation Prevents Piss Poor Performance. This time the plan consists of: "Do you want to go to the airport?" and "Sure!" Mind you, that's in the context of Glynn normally having several radios in his car and me not having a clue what to expect. The other day I actually had my first ever look at the location in Google Street View, only to discover that there's a shelter there, so hopefully we won't fry in the forecast 38 degrees Celsius, that's 100 degrees in Ray Bradbury's temperature scale, if you're wondering. Now, on the whole, this is a pretty low risk activity. Nobody is going to die if I don't manage to get the net going, though I do have Echolink on my phone, which reminds me, I should probably check if that still works. I'll put a pencil and a notepad in my pocket for logging and I'll bring a bottle or six of water and probably some coffee. Sorry, I can't help myself. In other words, it's entirely possible to get on air and make noise without having to go to the Nth degree of planning and still have fun. As it happens, fun is something that's been in short supply of late, so, that's also a welcome change. As an aside, in a completely unrelated and random observation, I recently installed a new font on my computer, called Hack. It's mono-spaced, sans-serif, intended for source code, and licensed under the MIT License. I'm using it right now and I'm in love. So secretly, between you and me, that's what goes for fun around here. Oh, in case you're wondering, no, I did not get paid to say that, the authors have no idea I exist, unless they're unexpectedly radio amateurs, I'm just a happy user. Also, if you're wondering about Echolink, no need to fret. I just tested and it just works straight out of the box. Gotta love that. Now, here's a question for you. When was the last time you spontaneously got on air to make noise? I'm Onno VK6FLAB

Foundations of Amateur Radio During the week I started a new project. If you know me at all, this is not unusual. Having worked in the IT industry for nearly 40 years it's also not unusual that projects have a way of surprising you and this project was no different. Recently I've been talking about antennas, a topic close to the heart of many amateurs and one that garners a lot of opinion and in my experience, much less in the way of facts, so being a firm believer of facts, I set out to add some of those to the discussion. After having described that the environment is not often discussed in the context of antenna behaviour, coupled with the personal experience that it has by far the biggest influence, I set out to discover if I could use my computing skills to simulate this problem to build a picture that would speak a thousand words. Prompted by a friend who shared with me a link to an opinion that stated that dipole antennas didn't have 2.15 dBi gain, but in fact, apparently, had 8.5 dBi gain, I was energised to find out where this number came from. I figured I'd spin up some antenna modelling software, use a standard model of a dipole, then simulate it at various heights above the ground and see what I could learn. Any good journey starts with a single step, so I started with looking for a generic model of a dipole antenna. I've played in this space before, so I was familiar with the fact that most, but not all, antenna modelling tools use a piece of software called NEC2 to do the actual calculations. Its models are described using text files ending in the .NEC extension. This software goes back to punch card days, so the format for the NEC2 files is essentially a stack of punch cards, so much so that every line in the text file is called a card and any software that uses the underlying NEC2 tool describes it in that way. I won't bore you with the syntax, it's, let's put it this way. If you've been around computers for as long as I have, you're familiar with a tool called "sendmail", which is known to be user-friendly, just very particular with whom it makes friends. The NEC2 card format is much the same. It's not that surprising, and for added nostalgia, NEC2 was written in FORTRAN, originally in 1981 at the Lawrence Livermore Labs by Jerry Burke and Andrew Poggio. It was later released to the public. There's translations to C and C++, but they use the same notion of cards, so no magic progress there. I started learning the syntax, and eventually came across a text-book with an example of cards that describe a dipole. Mind you, there were plenty of disclaimers around how poorly the ground was simulated and wouldn't you know it, the file format uses meters as the dimension, rather than wavelengths, so as far as I can tell, you can't simulate a quarter wave antenna, you have to simulate one of a specific length, so much for using a standard model of a dipole. I found a tool that uses Python to issue NEC2 commands and as a surprise to nobody, it too uses cards. I used it to discover that for a particular type of ground, at some unknown height, the optimum length for a 10m WSPR dipole antenna is 5,225.87 millimetres long, apparently. You know it's true, it says so right there on the screen. I'm skipping over having to compile the software that was supposed to be a ready made Python library, but I digress. There was a tool, written in TCL, that visualised NEC2 output, last updated 18 or so years ago and I unsuccessfully tried to make it work. Then there were those who suggested to fire up some random Windows tool on my Linux box, but as far as I can tell, I'd have to do the height adjustments manually, not ideal if you want to visualise from say, ground to geostationary orbit, one millimetre at a time and output an image at every step. I searched the net for others who would surely have trodden this path long before I came along, only to discover that my search-fu is clearly broken, or any website with promising information has long ago been booted off the Internet, leaving "For Sale" signs on the domain name. I came across one file which simulated a dipole in free space. It had, to use the NEC2 terms, 11 cards. When I run that through "nec2c", it generates a 12 megabyte file with over 104-thousand lines of output. Only takes 650 milliseconds to generate. If only I could visualise it. I also came across a whole range of physics programs, which is not that surprising, since essentially antenna design is physics, but those tools require that I start learning a whole new way of building antennas, apparently from electrons, preferably whilst getting a degree in physics with a specialisation in computational electromagnetics. Then there was the Wolfram Alpha notebook model for a simple dipole, only 3,200 lines of code, so, you know, trivial to use. So, here's the thing. Has nobody in living memory simulated a dipole at more than three heights and documented the process? Am I really the first human on the planet

Foundations of Amateur Radio Let's compare the same antenna in different locations... Over the years I've spent many hours building and testing antennas. I've talked about this and discussed how there is essentially an infinite variety of antennas that can exist. To give you a sense of this, picture a basic dipole antenna, two bits of wire, same length, connected to a feed-point. We're doing this experiment in space, so we're not concerned with trees or rope, or the ground for that matter, more on those shortly. We can make this dipole straight, or we can make it into a V-shape, or bend over the edges, or make each side into a half-circle and join them, or make them into a spiral, or kink the wires, or bend them over, or any number of variations. Every time you change something, the antenna radiation pattern changes and the antenna behaves differently. While at its heart the antenna might still be considered a dipole, essentially a change in radiation pattern effectively means a different antenna. In those changes or wire orientation alone we have already defined an infinite number of antennas, but that only scratches the surface. We can build an infinite variety of physical antennas. Consider the design of vertical antennas, loop antennas, log periodic antennas, yagi antennas, slot antennas, and beverage antennas to name a few. Once you start investigating antennas you'll discover just how many options there are and once you've acquired the antenna of your dreams, the work is only just beginning. To explain why this is the case, consider the process of finding an antenna to buy or build. You'll find breathless reports of how amazing an antenna is and how it allowed the operator to hear a mosquito land on the back of a container ship in the middle of a tropical cyclone whilst the sunspot activity was at an all time low. Right next to those reports you'll find another amateur describing how their dummy load performed better and cost less. If not those specific examples, you'll have no doubt found both positive and negative reviews for the very same antenna, often side-by-side and if you don't, you're not looking hard enough. Leaving aside the notion that someone is trying to discredit a commercial competitor or that the antennas are inadvertently physically different, because someone put it together incorrectly, there's plenty of opportunity for other reasons for this wide range of opinion. Let's take the popular G5RV antenna, invented in 1946 by Louis G5RV, who became a silent key on June 28, 2000. The antenna is a multi-band HF antenna and there are plenty of people offering plans and kits for this antenna. Ignoring the differences in plans, let's imagine that two amateurs purchased the exact same G5RV from the same batch from the same supplier. Both erect their antennas at their home shack, or QTH and get on air to make noise. At a local BBQ they get together and compare notes only to discover that the two antennas are behaving completely differently. How is this possible? What other factors might cause this experience? You're not going to like my answer, but "it depends". The height at which the antenna is erected, how tight you pull it between two trees, how you feed it, the type of coax you use, how much power your transmitter uses, how close it is to another object like a fence or a house, what type of ground is below the antenna, what the local noise floor is like, which direction it's oriented, which day you use it and finally, what colour clothes you're wearing at the time. That last one isn't strictly true, but it serves to highlight that some differences exist that are so innocuous as to be laughable, for example, have you considered the type of tree and how much foliage there is, when the lawn below the antenna was last watered, etc. My point is that some differences aren't obvious, but they can, and do, make an antenna behave differently. In other words, the environment around two identical antennas is hardly ever the same and thus the antenna system as a whole, since the environment and the antenna together combine into a system, are never the same. This means that when you go about finding an antenna that's suitable for you, the reviews you read are only part of the story. If the antenna needs ground radials that are physically not possible at your site, then that antenna is unlikely to be suitable for your situation, regardless of the glowing reviews. As I said, in my time I've built and bought plenty of antennas. I've also tried several by way of my local amateur radio club. I've operated a mobile station from my car, set-up a portable station in numerous locations using the exact same antenna, and learnt that while the environment is almost never discussed, it has by far the biggest influence on the performance of your antenna. My recommendation is to pick an antenna, any antenna, cheap is good, and start. Play with it, change how you erect it, set it up in different locations and I'd high

Foundations of Amateur Radio All antennas have a radiation pattern that charts on a sphere where it radiates more and where it radiates less than the theoretical isotropic radiator. This comparison is expressed as dBi antenna gain. There is a fundamental concept in antenna design called "reciprocity". Essentially it means that transmit and receive behaviour of an antenna is identical. In other words, the radiation pattern of an antenna applies for both transmitting and receiving of signals. Unfortunately, this does not mean that if two stations are communicating and one can hear the other, the reverse is also true. Let me explain why. Let's set the scene. Imagine two stations, me, VK6FLAB at Lake Monger, in Perth, Western Australia and Charles NK8O in the Lake of the Ozarks state park within the Ozark Mountains in central Missouri. We're both on the 10m HF band and in this story I've finally managed to learn Morse code and I'm "talking" to Charles, mind you, Charles apparently does have a microphone, so perhaps this might actually happen one day. To simplify things, we both have the same antenna, the same radio, the same power level, we both love low power or QRP operation, and while we're keeping it simple, we have the same ground conductivity and we're both experiencing the same very low noise levels. While we're constructing this fantasy, the communication paths for both our stations are identical. Note that I said paths, more on that shortly. In that situation, both Charles and I have the same experience. We can hear each other at the same level, our S-meter has the same reading, and apart from my current inability to actually use Morse code, our readability is identical. You might think this is "reciprocity", but it's not as simple as that. I'm parked near a lake in the middle of a city and often other vehicles come and go. One new arrival has a solar panel on the roof with a noisy inverter and suddenly the local noise in my location jumps from S0 to S6. The vehicle arrives whilst I'm transmitting, so at first nothing happens. Charles continues to hear my signal at the same level and at my end I'm blissfully unaware of any change, until I stop transmitting, when I hear the noise. Meanwhile, Charles starts his transmission and I cannot hear him because the local noise in my location is louder than his wanted signal. At this point, Charles still has the ability to hear me, but I can no longer hear him, even though our equipment is identical. The only change is the local noise floor at my location which interferes with my ability to receive the signals coming from Charles. This means that I can still send "again, again, local QRM" and I can do so as often as I want. Charles will hear this without any issue, but I won't hear his reply until the local noise stops. What this highlights is that two-way communication between two stations involves two signal paths. They might, or might not, follow the same journey through the ionosphere and be between two identical antennas, but the experience for either station can be, and almost always is, completely different. Because the ability to transmit isn't affected by local noise at the transmitter, it doesn't figure into the total path loss when you're calculating it for the receiving station. However, when the roles are reversed, it does. So when you're receiving, you need to take into account your local noise, but when you're transmitting, you don't. So, when Charles is transmitting to me, I need to take into account my local noise and ignore his, and when I'm transmitting to Charles, he needs to take into account his local noise, but not mine. This is how you can have so-called "alligator" stations, all mouth, no ears. The station is likely using high power with a high gain antenna in a noisy environment. This means that everyone can hear them, but because their local noise is so high, they can often only hear other alligators, but not the rest of the world who can perfectly hear them. If you encounter a station on-air that keeps calling CQ, regardless of how many people are calling back, that's an "alligator". So, the takeaway is that even if you can hear a station, it doesn't mean that they can hear you and the reverse is also true. You can be transmitting and heard all over the place, but if you're in a high noise environment, you might not be able to hear them. It's one reason that QRP stations prefer to work in low noise environments where they can hear many more stations. It reminds me of a funny story told by Wally VK6YS, now SK. In his early amateur radio days he operated from Cockatoo Island, an island off the north coast of Western Australia, near Yampi Sound, which is where his callsign came from. With a new radio and transverter for 6m, Wally had been calling CQ for weeks, but nobody would talk to him. Occasionally he'd hear a faint voice in the background. Meanwhile it transpired that amateurs across Japan were getting upset that he wasn't responding

Foundations of Amateur Radio After recently talking about noise, today I want to discuss gain, specifically antenna gain. When you say that your antenna has 18 dBi gain, what does that mean? This entire discussion starts with an isotropic radiator or antenna. It's often described as the perfect antenna, but rarely is there any description on how that actually works, so I'd like to start there. Before we dig in too much, it's worth remembering that an isotropic antenna is a thought experiment, it cannot physically exist, but it's a useful tool for comparing antennas. Antennas have a physical size. There's often a direct relationship between the size of the antenna and the frequencies for which it works best. A lower frequency means a longer wavelength and corresponding large antenna to handle that radio frequency. In contrast, an isotropic antenna is infinitesimally small and responds equally well for all frequencies. Similarly, unlike an actual antenna, an isotropic antenna is symmetric in all directions, that is, there's no difference between the back or the front, the top or the bottom, the left or the right. You can position an isotropic antenna in any orientation and there's no difference, not just no detectable difference, no actual difference. The radiation pattern is a perfect sphere. As I said, the isotropic antenna is an imaginary, let's call it, ideal antenna, that's used as the base reference to measure all antennas against. When you use the word gain in relation to an antenna, you're using the unit dBi and in doing so, you're comparing the antenna against this imaginary perfect isotropic antenna. When you see that the gain of an antenna is 2.15 dBi, you're saying that this antenna performs better than the isotropic antenna and does so by 2.15 dB. There's one "minor" detail missing in that statement. The full statement, often completely overlooked, is that this antenna performs better than the isotropic antenna and does so by 2.15 dB, in some directions, but not all. Said differently, antenna gain comes from distorting the ideal, perfect sphere into different shapes. For example, the 2.15 dBi gain of a horizontal dipole antenna distorts into a squashed doughnut on its side. In other words, there are directions where a dipole radiates better and has an increased gain when compared to an isotropic antenna, but there are also directions where it radiates worse, much worse, if at all. In the case of a dipole, it receives best from the side and worst in line with the antenna and I'll point out that the doughnut is also an idealised shape that in turn gets distorted by proximity to other objects, like the ground. Consider that a dipole has 2.15 dBi gain over an isotropic antenna. This means that, for some directions the gain is increased and for some directions it's decreased, perhaps even eliminated. In other words, in some direction, the antenna amplifies the signal and in other directions it attenuates the signal, potentially even to zero at a so-called null in an antenna radiation pattern. As I've said before, an antenna receives a combination of both wanted signal and unwanted noise. For an isotropic antenna all signals, from any direction, both wanted and unwanted, are treated the same. This is not true for an antenna that has gain. Consider an antenna that exhibits gain in one specific direction and loss in all other directions. If you were to point that antenna at a wanted signal, the incoming signal would be amplified in that direction and attenuated in all other directions. If noise comes from all directions equally, most of the noise would be attenuated and only a little bit of noise coming from the same direction as the wanted signal is amplified. Overall, this means that the total amount of incoming noise is reduced in comparison to the wanted signal. In other words, the noise floor is reduced and the signal level is increased, making the signal more audible above the noise. This means that the impact of antenna gain is that the Signal to Noise Ratio is improved for an incoming signal in comparison to local noise. Notice also, that the antenna gain works in multiple ways. It serves to improve the local signal to noise ratio, by attenuating noise and amplifying a wanted signal, but it also increases the transmitted signal that's sent towards the other station. Both affect your station's performance, but do so at different sides of the communication link and because we're talking about two separate signals, an incoming one and an outgoing one, the optimal direction might not be the same for both. So, now what do you think the impact might be of adding an 18 dBi Yagi to your station? I also have a supplementary question. If a commercial antenna is compared with a dipole, using the dBd unit, is the antenna compared to the entire radiation pattern of a dipole and if so, at what height from what type of ground and is that a useful comparison, or hiding the true performance of such an antenna? I'

Foundations of Amateur Radio Today I'd like to talk about noise, but before I do, I need to cover some ground. Recently I explored the idea that, on their own, neither antenna, nor coax, made a big difference in the potential for a contact when compared to the impact of path loss between two stations. I went on to point out that you'd be unlikely to even notice the difference in normal communications. Only when you're working at the margins, when the signal is barely detectable, would adding a single dB here or there make any potential difference. In saying that, I skipped over one detail, noise. Noise is by definition an unwanted signal that arrives together with a wanted signal at the receiver. In HF communications, noise comes from many sources, the galaxy, our atmosphere, and man-made noise from things like electrical switches, motors, alternator circuits, inverters and computers. The example I used was my 10 dBm beacon being reported by an Antarctic station. My signal report was about 5 dB above the minimum decode level and based on signal path calculations, -129 dBm, or around an S0 signal level. What that statement hides is that this is in the context of a noise level that's lower than -129 dBm. Remember, a negative dBm value means a fraction of a milliwatt. While you're considering that, think of the reality of an Antarctic station. This particular station, "Neumayer III" has three 75 kW diesel generators, a 30 kW wind turbine generator, 20 caterpillar trucks, 10 snowmobiles and 2 snow blowers and computers and technology to support 60 people, in other words, plenty of local noise. This makes it all the more remarkable that my 10 dBm beacon was heard and that there was an amateur there to set-up the receiver in the first place. Before I continue, picture mountain tops peaking through the top of a cloud layer as viewed from the window of an aeroplane. If the cloud layer increases in height, less and less mountain tops are visible, until at some point, only clouds are visible. Alternatively, if the cloud layer descends, more and more of the peaks are visible, until at some point no cloud remains and you see the mountains in all their magnificent glory. In that analogy, mountains represent signals and the cloud layer is the equivalent of the noise floor, and in a similar way, signals can be heard or not, depending on the relationship between the level of noise in comparison to the level of the signal. There's a name for this, it's called the signal to noise ratio or SNR, where a value of 0 dB means that noise and signal are at the same level, negative SNR values mean that the signal is weaker than the noise, positive SNR values means that the signal is stronger than the noise. If you know the power level in dBm for both the noise and the signal, you can subtract the two and end up with the signal to noise ratio. In reality, all receiving stations have to contend with noise. If I arbitrarily set the local noise floor at -100 dBm, somewhere halfway between S4 and S5, I'll mostly get laughed at by many stations, either because it's too high or too low. In case you're wondering, I've worked my station in both S0 noise and S9 noise environments and it's fun trying either and comparing. It's one of the reasons I often use a mobile station, to get away from urban noise around me, and you don't have to go far, a local park might be far enough from local noise to whet your appetite. Besides, -100 dBm is a nice round number to play with. You might recall that a typical path loss number for a 2,500 km contact on HF on the 10m band is about 129 dB. With a noise floor of -100 dBm, we immediately know how much output power is required to be heard above the noise. If the received signal has to be at least more than -100 dBm and we know that the path loss is 129 dB, then our transmitted signal needs to at least be enough to make up the difference. Said differently, if our output power is too low, the signal at the receive station will fall below the noise and they won't be able to hear us. So, if we start at say 30 dBm, have a path loss of 129 dB, we'll end up at -99 dBm, which is 1 dB above -100 dBm. Said in another way, the SNR for this is 1 dB. I'd like you to notice something. I've said nothing about the noise floor at the transmitter. We could have low noise, or horrendous noise, either way, it makes no difference to the receiver. What it hears is entirely dependent on the noise floor at the receiving station. I wonder if that observation changes anything about what you think the impact might be of adding an 18 dBi Yagi to your station? I'm Onno VK6FLAB

Foundations of Amateur Radio Recently I explained some of the reasons why I've shifted to using dBm to discuss power. You might recall that 1 Watt is defined as 1,000 mW and that's represented by 30 dBm. 10 Watts is 40 dBm, 400 Watts, the maximum power output in Australia is 56 dBm and 1,500 Watts, the maximum in the USA, is just under 62 dBm. My favourite power level, 5 Watts, is 37 dBm. I mentioned that using dBm allows us to create a continuous scale between the transmitted power and the received signal. On HF, an S9 report is defined as -73 dBm. Between each S-point lies 6 dB, so an S8 signal is -79 dBm, S7 is -85 dBm and so-on to S0, which is -127 dBm. Said differently, to increase the received signal by one S-point you need to quadruple the power output. Now, let's consider a contact with a 100 Watt station, 50 dBm. Let's imagine that the receiver reports an S8 signal. That means that between a transmitter output of 50 dBm and the received signal at -79 dBm, there's a loss of 129 dB. If we dial the power down to 5 Watts, our 37 dBm will be received at -92 dBm, and earn a S6 report, which, in my experience, is pretty common. If we instead use the maximum power permitted in Australia, we'd gain 6 dB and end up at -73 dBm, or S9. The maximum power output permitted in the United States, 62 dBm, is only 6 dB higher and not even enough to get you "10 over 9" at the other end. At this point I could say, see, "QRP, when you care to send the very least", and be done with it. While it's true in my not so humble opinion, that's not where I'm going with this. That 129 dB of loss is made up of a bunch of things. For example, there's the coax loss at either end, the antenna gain at either end and a big one, the path loss between the two antennas. Let's assume for a moment that coax loss and antenna gain cancel each other out. You might think that's nuts, but consider that 100 m of RG58 coax on the 10m band has a loss of around 8 dB and a dipole has an isotropic gain of 2.15 dBi. In case you're not sure what that means, a dipole has a gain of 2.15 dB over the ideal radiator, a theoretical isotropic antenna. Now it's unlikely that you are going to connect a dipole to 100 m of RG58, so let's say a quarter, or 25 m instead. The coax loss is also quartered, or about 2 dB, which pretty much means that your dipole gain and your coax loss essentially cancel each other out. So, as a working number, assuming both stations are similar and ignoring SWR mismatch, pre-amplifiers, filters, and all manner of other tweaks in the signal path, 129 dB loss is a good starting point to work with. If you use a free space path loss calculator, that's the equivalent of the loss for a 2,500 km contact on HF on the 10 m band. Now, if you were to replace the RG58 with something like RG213 coax, the loss drops from around 2 dB to 0.9 dB, so your signal just increased in strength by 1.1 dB, or not enough to make any difference in this example. Of course there's a benefit in using lower loss coax, I mean, 1.1 dB gain isn't nothing, but it really only matters when the conditions are marginal. If you're going to run your coax to the other side of a paddock, you might discover that your signal changes by a whole S-point, but realistically, most of the time you're not going to notice. Similarly, and perhaps more importantly, in the scheme of things, your antenna is also just fiddling around the edges when compared to the path loss of 129 dB. For example, if you double your antenna gain, you're only seeing an improvement of half an S-point and most likely you won't actually notice. Before you grab the nearest chicken to pluck feathers to come after me with, I'd like to point out that each element on their own has a minimal impact on the total system, but that doesn't mean that improving your station is useless, far from it. If you use quality coax, have an antenna that is performing well, is a good match to your transmitter and coax, use appropriate filters and pre-amplification, you're likely to make more contacts more often, but the bottom line is that you actually need to be on air to make noise and ultimately that's going to represent the biggest improvement in your station performance. Case in point, the other day my WSPR or Weak Signal Reporter beacon, with 10 dBm output, was reported 7,808 km away by DP0GVN, the club station of the German Antarctic Research Station "Neumayer III" in Dronning Maud Land, Antarctica, a first for me. WSPR reported that as a signal of -26 dB. Previously I proved that when WSPR reports -31 dB, about 75% of decodes are successful. In other words, we can think of my report as being 5 dB above the minimum decode level. This is interesting for several reasons, least of which is that a report of -26 dB doesn't appear to have a relationship to anything else, something which I've observed before. Looking further, if we use our notional 129 dB loss figure and start at the beacon power of 10 dBm, we end up at -119 dBm, which

Foundations of Amateur Radio The other day I went looking for a software defined radio or SDR for HF. This happened because all such devices on my desk are rated at higher frequencies and I've still not managed to fix the broken SMA board connector on the transverter I purchased over a year and a half ago. In case you're wondering, the design has two SMA connectors attached at either end of a printed circuit board, also known as a PCB. The board slides into a metal case and both connectors are tightened to either side of the case, which causes the problem when the circuit board is slightly shorter than the case and the nuts pull the connector apart, causing the device to fail. Replacing the SMA board connectors would be relatively simple, but they appear hard to come by and the micro SMA connectors that a friend purchased to help, changed the task into finding adaptors, which I've not managed to solve yet. I'm detailing this all for a purpose, trust me. Anyway, the hunt for an SDR for HF lead me to a project called "Radioberry". It's a design by Johan PA3GSB which is designed to be a so-called "hat" for a Raspberry Pi. Think of it as an expansion card to create functionality, in this case a radio capable of transmitting and receiving on HF, covering 0 to 30 MHz, perfect for my current needs. The design uses a Raspberry Pi computer to power and control the board, including programming the on-board FPGA, accessing the actual data and sharing that with the user, either via a touch screen, or using USB, Ethernet, Bluetooth or Wi-Fi. The board itself has two external connectors, one for transmit, one for receive and when you combine it with the Pi, fits neatly into a box which you could 3D print. Amplifier and band filters are left as an exercise to the enterprising amateur, though there is an amplifier design on the github repository. If you're curious, it's based on the work by the Hermes Lite 2 group. Johan specifically doesn't sell this device, instead you can choose to buy it from other enterprising individuals, or better still, build your own. Over the last few years I've started noticing several people in the so-called maker community, people, who a lot like radio amateurs, build stuff for fun, using online printed circuit board services. If you're unfamiliar with the concept, you can design a schematic, layout a PCB, have it manufactured and optionally even built and sent to you. To get an idea of what this might look like, I picked a random online supplier, uploaded the specifications for a Radioberry and costed the whole thing. Suffice to say that the biggest charge is the $50 set-up fee. Any enterprising engineer would have punched the "Buy Now" button and be done with it, but in some things I'm pretty cautious, so I haven't, yet. I don't know enough about the design or schematic to know how it works, to troubleshoot it, to fix any potential issues, or even to know what kinds of issues there might be, even if they're obvious to anyone with electronics experience. To make it clear, my electronics experience is rudimentary at best. I'm comfortable with block diagrams, understand the basic principles behind most passive elements, but if you're going to get into trace length and signal timing, I'm not anywhere even remotely qualified to troubleshoot, let alone spot problems. That's not to say that I am stopping before I start, the opposite is true. I'm using this as an experience to gently get my feet wet. Back to the apparently too detailed explanation of the transverter. Joining the dots you can probably guess where I'm going with this. Given the access to countless documented transverter designs, I feel comfortable enough to work on a design, construct a PCB and have it manufactured. At the rate I'm going, that should get a solution before I can find a PCB edge-mounted SMA connector, well, at least that's my excuse. I'm also eyeing off this same process to build a logging volt meter, since the Internet seems to believe that I should pay hundreds of dollars for a volt meter and an I/O port, even if the chip inside costs all of $6. Oh, the transverter I purchased a year and a half ago costs three times as much as having five of them built on demand, so there's that. For all my life I've been a firm believer in software. I've also been on a computer driven manufacturing journey for a couple of years, still in the process of commissioning my new toys, much to the merriment of some of my fellow amateurs and the idea that I can have a circuit design built and shipped to my door just makes me tingle with anticipation. If you're already ahead of me on this journey, please don't hesitate to point at any potholes on the road and if you're following along, if you break it, you get to keep both parts. I'm Onno VK6FLAB

Foundations of Amateur Radio If you've been following my amateur radio journey, you'll have likely noticed that I've been straying from the fold. The words I use for power have been changing. I've reduced references to Watt and increased use of the term decibel. Initially this was incidental, recently it's been more of a deliberate decision and I'd like to explain how this came to be. It starts with representing really big and really small numbers. Let's start big. On 14 September, 2015 the first direct observation of gravitational waves was made when a pair of black holes with a combined estimated weight of 65 solar masses merged. The signal was named GW150914, combining "Gravitational Wave" and the observation date to immortalise the event. Following the collision, it was estimated that the radiated energy from the resulting gravitational waves was 50 times the combined power output of all the light from all the stars in the observable universe. As a number in Watts, that's 36 followed by 48 zeros. If you're curious, there's even a word for that, 36 Quindecillion Watts. Now let's look at small. The typical signal strength received from a GPS satellite, like say by your phone, is about 178 attowatts, or in Watts, 0.000 and so on, in all, 13 zeros between the decimal point and then 178. What if I told you that the energy associated with the collision of those two black holes could be expressed in comparison with a milliwatt. Remember, this collision emitted more energy than all the output of light from all the stars in the observable universe. The expression for all that power is 526 dBm. Similarly, the tiny received GPS signal can be expressed as -127.5 dBm. Just let that sink in. All the power in the observable universe through to the minuscule power received by the GPS in your phone, all expressed between 526 dBm and -127.5 dBm, and not a zero in sight. As I mentioned, the unit dBm relates to a milliwatt. As a starting point, let me tell you that 1 Watt is 1,000 milliwatts and is represented by 30 dBm. The decibel scale doesn't work quite the same as other number ranges you might be used to. Adding the value 3 doubles its size and adding the value 10 increases its size by a factor 10. For example, to double power from 1 Watt or 30 dBm, add 3 and get 33 dBm, which is the same as 2 Watts. If you want to increase 1 Watt by a factor 10, again, starting with 30 dBm, add 10 and get 40 dBm which is 10 Watts. Similarly, 50 dBm is 100 Watts and 60 dBm is 1,000 Watts. Going the other way, halving power, remove 3. So taking 3 from 60 dBm is 500 Watts or 57 dBm. Dividing power by a factor 10 works the same, take 10. So 47 dBm is 50 Watts and 37 dBm is 5 Watts. If you get lost, remember, dBm relates to a milliwatt. 1 Watt is 1,000 milliwatts and is represented by 30 dBm. Divide by a factor 1,000, remove 30 and end up with 0 dBm, which is the same as 1 milliwatt. I'll say that again, 0 dBm is the same as 1 milliwatt. It takes a little getting used to, but you can do some nifty things. For example, remove 10 to get a tenth of a milliwatt, or -10 dBm. This same process of adding and subtracting applies in other ways too. Attenuation, or making a signal weaker, and amplification, or making a signal stronger can use the same rules. For example, if you apply 3 dB of attenuation, you're making the signal 3 dB weaker, or halving it, so you subtract 3 dB from your power output. If your amplifier is rated at 6 dB gain, you're quadrupling the output and you add 6 dB to your power output. Similarly, if you talk about the gain of an antenna, you add it. If the gain is 20 dBi, you add it to the power output. You can use this for coax loss calculations as well. A 100m length of RG-58 at 28 MHz has a loss of 8 dB. You can directly subtract this from the power output of the transmitter and know precisely how much power is making it to the antenna. There's more. The radio amateur S9 signal strength on HF, something which we consider to be a strong signal, can be expressed as -73 dBm or a very small fraction of a milliwatt. An S8 signal is 6 dB weaker, or -79 dBm. A 20 over 9 report is -53 dBm. I will point out that this is at 50 Ohm. As a result, we now have a continuous scale for all the elements in the transmission chain between the transmitter and the receiver. While I'm here, I've already mentioned that negative dBm readings relate to fractions of a milliwatt, so values between 0 and 1. This highlights one limitation of this scale. We cannot represent 0 Watts. Mind you, that doesn't happen all that often. The thermal noise floor in space at 1 Hz bandwidth, that's at 4 kelvins, is -192.5 dBm, which practically means the minimum level of power we need to express. It's also a good value to remember because if you're doing funky calculations and you end up with a number less than -192.5 dBm, you can pretty much guarantee that you've probably made a boo-boo. 0 Watts using the dBm scale is represented by negative infinity, or essentiall

Foundations of Amateur Radio Between decibels and milliwatts ... As you might recall, I've been working towards using a cheap $20 RTL-SDR dongle to measure the second and third harmonic of a handheld radio in an attempt to discover how realistic that is as a solution when compared to using professional equipment like a Hewlett Packard 8920A RF Communications Test Set. I spent quite some time discussing how to protect the receiver against the transmitter output and described a methodology to calculate just how much attenuation might be needed and what level of power handling. With that information in-hand, for reference, I used two 30 dB attenuators, one capable of handling 10 Watts and one capable of handling 2 Watts. In case you're wondering, it's not the dummy load with variable attenuation that I was discussing recently. I ended up using a simple command-line tool, rtl-power, something which I've discussed before. You can use it to measure power output between a set of frequencies. In my case I measured for 5 seconds each, at the base frequency on the 2m band, on the second and on the third harmonic and to be precise, I measured 100 kHz around the frequencies we're looking at. This generated a chunk of data, specifically I created just over a thousand power readings every second for 15 seconds. I then put those numbers into a spreadsheet, averaged these and then charted the result. The outcome was a chart with three lines, one for each test frequency range. As you'd expect, the line for the 2m frequency range showed a lovely peak at the centre frequency, similarly, there was a peak for the other two related frequencies. The measurement data showed that the power measurement for 146.5 MHz was nearly 7 dB, for 293 MHz it was -44 dB and for 439.5 MHz it was -31 dB. If you've been paying attention, you'll notice that I used dB, not dBm or dBW in those numbers, more on that shortly. From a measurement perspective we learnt that the second harmonic is 51 dB below the primary power output and the third harmonic was about 38 dB below the primary power output. First observation to make is that these numbers are less than shown on the HP Test Set where those numbers were 60 dB and 62 dB respectively. Second observation, potentially more significant, is that pesky dB thing I skipped over earlier. If you recall, when someone says dB, they're referring to a ratio of something. When they refer to dBm, they're referring to a ratio in relation to 1 milliwatt. This means that when I say that the power reading was 7 dB, I'm saying that it's a ratio in relation to something, but I haven't specified the relationship. As I said, that's on purpose. Let me explain. When you use an RTL-SDR dongle to read power levels, you're essentially reading numbers from a chip that is converting voltages to numbers. In this case the chip is an Analog to Digital Converter or an ADC. At no point has any one defined what the number 128 means. It could mean 1 Volt, or it could mean 1 mV, or 14.532 mV, or something completely different. In other words, we don't actually know the absolute value that we're measuring. We can only compare values. In this case we can say that when we're measuring on the 2m band we get a range of numbers that represent the voltage measured along those frequencies. When we then measure around the second harmonic, we're doing the same thing, possibly even using the same scale, so we know that if we get 128 back both times we might assume the voltage is the same in both cases, we just don't actually know how much the voltage is. We could say that there's no difference between the two, or 0 dB, but we cannot say how high or low the voltage is. This is another way of describing something I've discussed before, calibration. So, if I had a tool that could output a specific, known RF power level, and fed that into the receiver and measured, I could determine the relationship between my particular receiver and that particular power level. I could then measure at all three frequencies and determine if the numbers were actually the same for these three frequencies, which is what I've been assuming, but we don't actually know for sure right now. So, at this point we need a known RF signal generator. The list of tools is growing. I've already used a NanoVNA to calibrate my attenuators and I've used a HP RF Communications Test Set to compare notes with. At this point you might realise that we're not yet able to make any specific observations about using a dongle to make harmonic measurements, but you can make pretty pictures... There's a good chance that you're becoming frustrated with this process, but I'd like to point out that at the beginning of this journey I can tell you that I had no idea what the outcome might be and obviously, that's the nature of experimentation. If you have some ideas on how to explore further, feel free to get in touch. I'm Onno VK6FLAB

Foundations of Amateur Radio Over the weekend a friend of mine convinced me to help plant some trees. Mind you, I was told that this was going to be a blue tree painting day. The Blue Tree Project is now a global awareness campaign that paints dead trees blue to spread the message that "it's OK to not be OK", and help break down the stigma that's still largely attached to mental health. In the process, I learnt that my physical stamina is not what it once was and my current appetite for bending over and shovelling dirt is, let's call it, muted. After the digging and the sausage sizzle under the branches of an actual blue tree, there was some opportunity for playing radio, something I haven't done in much too long. I wasn't sure when I last got into the fresh air to actually listen, but I must confess, the coax cable that I picked up out of my shed had been hanging there for several years. The location where we planned to play was in a rural setting, right next to a dam, which surprisingly actually had water in it. The idea was to set-up a vertical antenna with a couple of ground radials, plug in a radio and have a listen. I have to say, after the digging I was really looking forward to this. My piece of coax, about 20 meters long, was used to connect the antenna to the radio so we could sit in the shade whilst the antenna stood out in the sun near the dam. The antenna, a telescopic one, came with a ground spike and about eight radials and needed to be tuned to some extent, as-in, near-enough is close enough, since we had an antenna tuner with our radio. To achieve the tuning we wanted to connect a NanoVNA to the coax which was the first challenge. The BNC connectors on my coax were pretty dull, likely a combination of poor quality, accumulated dust, humidity and lack of use. As an added bonus the centre pin on one end seemed a little bent. After working out how to get an SMA adaptor into the connectors we were in business. Connected up between the antenna and the NanoVNA we set out to get things lined up. The SWR on the display, hard to read in the full sun at the best of times, seemed to be a little odd. Not something I could put my finger on, but if you've seen enough SWR plots you know what it's supposed to look like and for some reason it didn't. We bravely carried on, connected the radio to the coax and started tuning around. Didn't seem to be a lot of activity on the 20m band. We couldn't hear the local NCDXF beacon which was odd. Also no FT8 activity, also odd. If anything, it seemed like there was nothing happening at all. Before we continue, I'll point out that this can happen with a big enough burp from the Sun. I hadn't seen any alerts, so I wasn't buying it. We removed my coax, plugged in something much shorter and the bands came alive with all the activity we'd been expecting. And then it started to rain. Seriously. Finally got out into the world, got radio activity going, had actual signals to tune to and it starts raining. Glynn VK6PAW and I took one look at each other, shook our heads and dashed for the radio to bring it under shelter. I put on my raincoat, and together we disassembled the antenna and the station and went home. Clearly, my coax was faulty. Lesson learnt. Test your coax before you go out and you'll have a better outcome. About that. Today, a week later, I'm sitting on the floor of my shack with the offending coax between my legs, surrounded by adaptors, a NanoVNA, a RigExpert, a dummy load, a short and an open terminator. No matter how I test, no matter what I test, everything is as it should be. I can tell you that the Time Domain Reflectometry shows me that the coax is 25.8m long, useful information, but not really any surprise. There's also no significant return loss, unless you head for 1 GHz, but even then it's perfectly respectable, if anything, better than I expected. There are no loose connections, nothing rattling, nothing amiss. The only thing that I can even begin to think might be the case is that one of the centre pins on one end of the coax is slightly shorter. Combined with "close enough is good enough" when I attached the SMA adaptor in the field, might account for a connection that never got made, since the adaptor wasn't seated deep enough. So, I'm not quite ready to cut off the connectors and re-terminate this coax. I'll be taking it into the field again, but I'll make sure that I bring an alternative, just in case. I'm also leaving the SMA adaptors connected to the coax. Future me will thank me. Oh, yes, in-case you're wondering, I'm slowly working out how to improve my stamina. That was not fun. If you want to know more about Blue Trees and its message, check out the BlueTreeProject.com.au website and if you ever just want to talk, get in touch. I'm Onno VK6FLAB

Foundations of Amateur Radio Before we start I should give you fair warning. There are many moving parts in what I'm about to discuss and there's lots of numbers coming. Don't stress too much about the exact numbers. In essence, what I'm attempting is to explore how we can reduce the power output from a transmitter in such a way that it doesn't blow up a receiver whilst making sure that the signal is strong enough that we can actually measure it. With that in mind, recently I discussed the idea of adding a series of attenuators to a transmitter to reduce the power output by a known amount so you could connect it to a receiver and use that to measure output power at various frequencies. One hurdle to overcome is the need to handle enough power in order to stop magic smoke from escaping. None of my attenuators are capable of handling more than 1 or 2 Watts of power, so I cannot use any of them as the first in line. As it happens, a good friend of mine, Glynn VK6PAW, dropped off a device that allows you to divert most of the power into a dummy load and a small amount into an external connector. In effect creating an inline attenuator capable of handling 50 Watts. The label doesn't specify what the attenuation is, so I measured it using a NanoVNA. To make our job a little interesting, it isn't constant. Between 10 kHz and 1 GHz, the attenuation decreases from 70 dB to 10 dB. We want to measure at a base frequency on the 2m band and its second and third harmonic. The attenuation at those frequencies varies by 11 dB, which means we'll need to take that into account. So, let's subject our currently imaginary test set-up to some sanity checking. Our receiver is capable of reading sensible numbers between a signal strength of -127 dBm and -67 dBm and we'll need to adjust accordingly. If we transmit an actual 20 Watt carrier, that's 43 dBm. With 110 dB of attenuation, we end up at -67 dBm, which is right at the top end of what we think the receiver will handle. If we're using something like 5 Watts, or 37 dBm, we end up at -73 dBm, which is well above the minimum detectable signal. Our best harmonic measurement was around -30 dBm, which means that with 110 dB of attenuation, we end up at -140 dBm, which is 13 dB below what we think we can detect. So, at this point you might wonder if this is still worth our while, given that we're playing at the edges and to that I say: "Remind me again why you're here?" First we need to attenuate our 20 Watts down to something useful so we don't blow stuff up. Starting with 110 dB attenuation, we can measure our base carrier frequency and its harmonics and learn just how much actual power is coming out of the transmitter. Once we know that, we can adjust our attenuation to ensure that we end up at the maximum level for the receiver and see what we are left with. So, let's look at some actual numbers, mind you, we're just looking at calculated numbers, these aren't coming from an actual dongle, yet. Using Glynn's dummy load as the front-end, at 146.5 MHz, the attenuation is about 30 dB. If we look at a previously measured handheld and rounding the numbers, it produced 37 dBm. That's the maximum power coming into our set-up. With 30 dB of attenuation from Glynn's dummy load, that comes down to 7 dBm. We'll need an additional 74 dB of attenuation to bring that down to -67 dBm, in all we'll need 104 dB of attenuation. The third harmonic for that radio was measured at -26 dBm. So, with a 104 dB of attenuation that comes out at -130 dBm, which is below the minimum detectable signal supported by our receiver. However, remember that I told you that our dummy load had different attenuation for different frequencies? In our case, the attenuation at 439.5 MHz is only 19 dB, not 30, so in actual fact, we'd expect to see a reading of -119 dBm, which is above the minimum detectable signal level. I realise that's a lot of numbers to digest, and they're specific to this particular radio and dummy load, but they tell us that this is possible and that we're potentially going to be able to measure something meaningful using our receiver. I'll also point out that if you're going to do this, it would be a good idea to take notes and prepare what numbers you might expect to see because letting the magic smoke escape might not be one of your desired outcomes. Speaking of smoke, what happens if you consider changing the attenuation when you're measuring at another frequency, like say the second or third harmonic and you see a reading close to, or perhaps even below the detectable signal level as we've just discussed. You might be tempted to reduce the attenuation to increase the reading, but you need to remember that the transmitter is still actually transmitting at full power into your set-up, even if you're measuring elsewhere. This is why for some radios you'll see a measurement that states that the harmonics are below a certain value because the equipment used doesn't have enough range to provide an ac

Foundations of Amateur Radio Recently I had the opportunity to use a piece of professional equipment to measure the so-called unwanted or spurious emissions that a transceiver might produce. In describing this I finished off with the idea that you could use a $20 RTL-SDR dongle to do these measurements in your own shack. I did point out that you should use enough attenuation to prevent the white smoke from escaping from your dongle, but it left a question, how much attenuation is enough? An RTL-SDR dongle is a USB powered device originally designed to act as a Digital TV and FM radio receiver. It's normally fitted with an antenna plugged into a socket on the side. I'll refer to it more generically as a receiver because much of what we're about to explore is applicable for other devices too. Using your transceiver, or transmitter, as a signal source isn't the same as tuning to a broadcast station, unless you move it some distance away, as-in meters or even kilometres away, depending on how much power you're using at the time. Ideally we want to connect the transmitter output directly to the receiver input so, at least theoretically, the RF coming from the transmitter stays within the measuring set-up between the two devices. Assuming you have a way to physically connect your transmitter to your receiver we need to work out what power levels are supported by your receiver. For an RTL-SDR dongle, this is tricky to discover. I came across several documents that stated that the maximum power level was 10 dBm or 0.01 Watt, but that seemed a little high, since an S9 signal is -73 dBm, so I kept digging and discovered a thoughtful report published in August 2013 by Walter, HB9AJG. It's called "Some Measurements on DVB-T Dongles with E4000 and R820T Tuners". There's plenty to learn from that report, but for our purposes today, we're interested in essentially two things, the weakest and strongest signals that the receiver can accommodate. We're obviously interested in the maximum signal, because out of the box our transmitter is likely to be much too strong for the receiver. We're going to need to reduce the power by a known amount using one or more connected RF attenuators. At the other end of the scale, the minimum signal is important because if we add too much attenuation, we might end up below the minimum detectable signal level of the receiver. Over the entire frequency range of the receivers tested in the report the minimum varies by about 14 dB, so let's pick the highest minimum from the report to get started. That's -127 dBm. What that means is that any signal that's stronger than -127 dBm is probably going to be detectable by the receiver and for some receivers on some frequencies, you might be able to go as low as -141 dBm. At the other end of the scale the report shows that the receiver range is about 60 dB, which means that the strongest signal that we can use is -67 dBm before various types of distortion start occurring. For comparison, that's four times the strength of an S9 signal. So, if we have a 10 Watt transmitter, or 40 dBm, we need to bring that signal down to a maximum of -67 dBm. In other words we need at least 107 dB of attenuation and if we have a safety margin of two, we'll need 110 dB of attenuation, remember, double power means adding 3 dB. So, find 110 dB of attenuation. As it happens, if I connect most of my attenuators together, I could achieve that level of attenuation, but there's one further issue that we'll need to handle and that's power. As you might recall, an attenuator has several attributes, the most obvious one is how much attenuation it brings to the party. It's specified in dB. My collection of attenuators range from 1 dB to 30 dB. Another attribute is the connector it comes with, I have both N-type and SMA connectors in my collection, so I'll need some adaptors to connect them together. One less obvious and at the cheap end of the scale, often undocumented, aspect of an attenuator is its ability to handle power. Essentially we're turning an RF signal into heat, so an attenuator needs to be able to dissipate that heat to handle what your transmitter is throwing at it. I said that from a safety perspective I'd like to be able to handle 20 Watts of power. Fortunately we don't need all our attenuators to be able to handle 20 Watts, just the first one directly connected to the transmitter. If we were to use a 20 Watt, 30 dB attenuator, the signal through the attenuator is reduced to 0.02 Watts and the next attenuator in line only needs to be able to handle that power level and so-on. To get started, find about 110 dB of attenuation, make sure it can handle 20 Watts and you can start playing. Before you start keying up your transmitter, how might you handle a range of different transmitters and power levels and can you remove an attenuator when you test on a different frequency? On that last point, let me say "No", you cannot remove the attenuator when you're measuring a differe

Foundations of Amateur Radio At a recent local HAMfest we set-up a table to measure second and third harmonic emissions from any handheld radio that came our way. The process was fun and we learnt lots and in due course we plan to publish a report on our findings. When we received a handheld, we would disconnect the antenna, and replace it with a short length of coax and connect it to a spectrum analyser. We would then trigger the Push To Talk, or PTT button and measure several things. We'd record the actual frequency and how many Watts that the transmitter was producing and then record the power level in dBm for the base frequency, double that frequency and triple that frequency. In other words, we'd record the base, second and third harmonics. This resulted in a list of numbers. Frequency and power in Watts are obvious, but the three dBm numbers caused confusion for many visitors. The most perplexing appeared to be that we were producing negative dBm numbers, and truth be told, some positive ones as well, we'll get to those in our report. How can you have negative power you ask? As I've discussed before. A negative dBm number isn't a negative value of power, it's a fraction, so, -30 dBm represents 0.000001 Watts and you'd have to admit that -30 dBm rolls off the tongue just a little easier. What we measured and logged was the overall transmitter output and at specific frequencies. As I've discussed previously, if you transmit using any transceiver, you'll produce power at the intended frequency, but there will also be unintended or unwanted transmissions, known as spurious emissions. The International Telecommunications Union, or ITU, has standards for such emissions. In Australia the regulator, the ACMA, uses the ITU standard for radio amateurs, but I should point out that this might not be the case where you are. It's entirely possible, and given human diversity, probable even, that there are places where there are more stringent requirements, so bear that in mind. I'll state the standard and then explain. For frequencies greater than 30 MHz, the spurious emission must not exceed the lesser of 43 + 10 * log (power) or 70 dB. That might sound like gobbledegook, so let's explore. First thing to notice is that this is for transmissions where the transmitter is tuned to a frequency greater than 30 MHz, there's a separate rule for frequencies less than 30 MHz and the ITU also specifies a range of different limits for special purpose transmitters like broadcast radio and television, space services, and others. Second thing is that the spurious emissions are calculated based on total mean output power. This means that your spurious emissions are considered in relation to how much power you're using to transmit and it implies that for some transmitters you can be in compliance at one power level, but not at another, so keep that in mind. The phrase "the lesser of", means that from a compliance perspective, there's a point at which power levels no longer determine how much attenuation of spurious emissions is required. You can calculate that point. It's where our formula hits 70 dB, and that is at 500 Watts. In other words, to meet the ITU standard, if you're transmitting with less than 500 Watts, you're subject to the formula and if you're transmitting with more than 500 Watts, you're required to meet the 70 dB standard. It means that, at least in Australia, spurious emissions for amateurs are dependent on transmitter power because the maximum permitted power is currently 400 Watts for an amateur holding a so-called Advanced License. Now I'll also point out explicitly that the emission standards that the ITU specifies are for generic "radio equipment", which includes amateur radio, but also includes anything else with a transmitter. One thing to mention is that spurious emissions aren't limited to the second and third harmonics that we measured, in fact they're not even limited to harmonics. If you're using a particular mode then anything that's transmitted outside the bandwidth of that mode is considered a spurious emission and there are standards for that as well. As an aside, it was interesting to me that in many cases amateur radio is treated separately from other radio services, but the ITU considers our community just one of several spectrum users and it's good to remember that the entire universe is playing in the same sandbox, even if only some of it is regulated by the ITU and your local regulator. So, let's imagine that you have a handheld radio that has a total mean power output of 5 Watts. When you calculate using the formula, you end up at 50 dB attenuation. In other words, the spurious emissions may not exceed -13 dBm. So, if your radio measures -20 dBm on the second harmonic, it's compliant for that harmonic, but if it measures -10 dBm, it's not. I should also point out that this is for each spurious emission. About half the radios we tested had a second harmonic that was worse than the third har

Foundations of Amateur Radio There's nothing quite as satisfying as the click of a well designed piece of equipment. It's something that tickles the brain and done well it makes the hairs stand up on the back of your neck. If time was on my side and I wasn't going somewhere else with this, I'd now regale you with research on the phenomenon, I'd explore the community of people building mechanical keyboards and those who restore equipment to their former glory, instead I'm encouraging you to dig whilst I talk about the second and third harmonics. This is about amateur radio after all. Over the years there has been a steady stream of commentary around the quality of handheld radios. Some suggest that the cheaper the radio, the worse it is. Given that these kinds of radios are often the very first purchase for an aspiring amateur it would be useful to have a go at exploring this. When a radio is designed the aim is for it to transmit exactly where it's intended to and only there. Any transmission that's not where you plan is considered a spurious emission. By carefully designing a circuit, by adding shielding, by filtering and other techniques these spurious emissions can be reduced or eliminated, but this costs money, either in the design stage, or in the cost of materials and manufacturing. It's logical to think that the cheaper the radio, the worse it is, but is it really true that a cheap radio has more spurious emissions than an expensive one? To give you an example of a spurious emission, consider an FM transmitter tuned to the 2m amateur band, let's say 146.5 MHz. If you key the radio and all is well, the radio will only transmit at that frequency, but that's not always the case. It turns out that if you were to listen on 293 MHz, you might discover that your radio is also transmitting there. If you're familiar with the amateur radio band plan, you'll know that 293 MHz is not allocated as an amateur frequency, so we're not allowed to transmit there, in fact, in Australia that frequency is reserved for the Australian Department of Defence, and there's an additional exclusion for the Murchison Radio-astronomy Observatory. 293 MHz isn't a random frequency. It's twice 146.5 MHz and it's called the second harmonic. There's more. If you multiply the base frequency by three, you end up at 439.5 MHz, the third harmonic. In Australia, that frequency falls into the amateur allocation as a second use, its primary use is again the Department of Defence. These two transmissions are examples of spurious emissions. To be clear, the transmitter is tuned to 146.5 MHz and these unintended extra signals come out of the radio at the same time. This is bad for several reasons, legal and otherwise. The first, obvious one, is that you're transmitting out of band, which as an amateur you already have no excuse for, since getting your license requires you to understand that this is strictly not allowed. The International Telecommunications Union, or ITU, has specific requirements for what's permitted in the way of spurious emissions from an amateur station. Spurious emissions also mean that there is energy being wasted. Instead of the signal only coming out at the intended frequency, some of it is appearing elsewhere, making the 5 Watts you paid for less effective than you hoped for. So, what's this got to do with the click I started with? Well, thanks to Randall, VK6WR, I have on loan a heavy box with a Cathode Ray Tube or Green CRT screen, lots of buttons and knobs and the ability to measure such spurious emissions. It's marked "HP 8920A RF Communications Test Set". Using this equipment is very satisfying. You switch it on and a fan starts whirring. After a moment you hear a beep, then the screen announces itself, almost as-if there's a PC in there somewhere - turns out that there is and the beep is the Power On Self Test, or POST beep. Originally released in 1992, this magic box can replace 22 instruments for transceiver testing. I started downloading user manuals, oh boy, there's lots to learn. Bringing back lots of memories, it even has a programming language, Instrument BASIC, to control it. Where have you been all my life? Turns out that in 1992 this piece of kit cost as much as my car. Anything for the hobby right? At the next HAMfest I'll be using it to measure as many handhelds as I can get my hands on and taking notes. I have no idea how many I'll be able to test, but I'm looking forward to putting some numbers against the repeated claims of quality and price. I can tell you that a couple of weeks ago I got together with Randall and Glynn VK6PAW and spent an enjoyable afternoon testing several radios and there are some surprising results already. Perhaps this is something you might attempt at your next community event, gather data, rather than opinions... I'm Onno VK6FLAB

Foundations of Amateur Radio If you walk into your radio shack and switch on a light, the result is instantaneous, one moment it's dark, the next it's not. What if I told you that as immediate as it appears, there is actually a small delay between you closing the circuit and the light coming on. Likely the distance between your switch and your light is less than say 10 meters, so the delay is likely to be less than 33 nanoseconds, not something you'd notice unless you're out to measure it. What if your light switch is 3,200 km away? That's the length of the first transatlantic telegraph cable in 1858. Let's start with the notion that between the action of closing a switch, or applying a voltage at one end of the cable and it being seen at the other end takes time. If we ignore the wire for a moment, pretending that both ends are separated by vacuum, then the delay between the two ends is just over 10 milliseconds because that's how long it takes travelling at the speed of light. One of the effects of using a cable is that it slows things down. In case you're curious, the so-called Velocity Factor describes by how much. A common Velocity Factor of 66 would slow this down by 66%. This means that there is a time when there is voltage at one end and no voltage at the other. There are a few other significant and frequency dependent things going on, we'll get to them, but before we go any further, it's important to consider a couple of related issues. Ohm's Law, which describes the relationship between voltage, current and resistance in an electrical circuit was first introduced in 1827 by Georg Ohm in his book: "The Galvanic Chain, Mathematically Worked Out". Initially, his work was not well received and his rival, Professor of Physics Georg Friedrich Pohl went so far as to describe it as "an unmistakable failure", convincing the German Minister for Education that "a physicist who professed such heresies was unworthy to teach science." Although today Ohm's Law is part and parcel of being an amateur, it wasn't until 1841 that the Royal Society in London recognised the significance of his discovery, awarding the Society's oldest and most prestigious award, the Copley Medal, in recognition for "researches into the laws of electric currents". I'll point out that Ohm only received recognition because his work was changing the way people were starting to build electrical engines and word of mouth eventually pressured the Royal Society into the formal recognition he deserved. I also mentioned the speed of light in relation to the delay between applying a voltage and it being seen at the other end, but it wasn't until 1862 when James Clerk Maxwell published a series of papers called "On Physical Lines of Force" that light speed was actually derived when he combined electricity and magnetism and proved that light was an electromagnetic wave, and that there were other "invisible" waves, which Heinrich Rudolph Hertz discovered as radio waves in 1888. How we understand transmission lines today went through a similar discovery process. Your radio is typically connected to an antenna using a length of coaxial cable, which is a description for the shape the cable has, but the nature of the cable, what it does, is what's known as a transmission line. If you looked at the submarine telegraph cable of 1858, you'd recognise it as coaxial cable, but at the time there wasn't much knowledge about conductance, capacitance, resistance and inductance, let alone frequency dependencies. James Clerk Maxwell's equations weren't fully formed until 1865, seven years after the first transatlantic telegraph cable was commissioned and the telegraph equations didn't exist until 1876, 18 years after the first telegram between the UK and the USA. In 1854 physicist William Thomson, was asked for his opinion on some experiments by Michael Faraday who had demonstrated that the construction of the transatlantic telegraph cable would limit the rate or bandwidth at which messages could be sent. Today we know William Thomson as the First Lord Kelvin, yes, the one we named the temperature scale after. Mr. Thomson was a prolific scientist from a very young age. Over a month, using the analogy with the heat transfer theory of Joseph Fourier, Thomson proposed "The Law of Squares", an initial explanation for why signals sent across undersea cables appeared to be smeared across time, also known as dispersion of the signal, to such an extent that dits and dahs started to overlap, requiring the operator to slow down in order for their message to be readable at the other end and as a result, message speed for the first cable was measured in minutes per word, rather than words per minute. Today we know this phenomenon as intersymbol interference. It wasn't until 1876 that Oliver Heaviside discovered how to counter this phenomenon using loading coils based on his description of what we now call the Heaviside condition where you can, at least mathematically, create a

Foundations of Amateur Radio The first official telegram to pass between two continents was a letter of congratulations from Queen Victoria of the United Kingdom to President of the United States James Buchanan on 16 August 1858. The text is captured in the collection of the US Library of Congress. It's a low resolution image of a photo of a wood engraving. Based on me counting the characters, the text from the Queen to the President is about 650 characters. IEEE reports it as 98 words, where my count gives 103 words or 95 words, depending on how you count the address. Due to a misunderstanding between the operators at either end of the 3,200 km long cable, the message took 16 hours to transmit and 67 minutes to repeat back. If you use the shortest duration, the effective speed is just over one and a half Words Per Minute or WPM. That's not fast in comparison with speeds we use today. Until 2003, the ITU expected that emergency and meteorological messages should not exceed 16 WPM, that a second class operator could achieve 20 WPM and a first class operator could achieve 25 WPM. To put the message speed in context of the era, in 1856, RMS Persia, an iron paddle wheel steamship and at the time, the largest ship in the world, won the so-called "Blue Riband" for the fastest westbound transatlantic voyage between Liverpool and Sandy Hook. The journey took nine days, 16 hours and 16 minutes. Similarly, it wasn't until 1861 that a transcontinental telegraph was established across the United States. In 1841 it took 110 days for the news of the death in office of President William Henry Harrison to reach Los Angeles. Today that distance is covered by a 39 hour drive, a 5 hour flight, and about 12 milliseconds on HF radio. So, while the speed of the message might not be anything to write home about today, at the time it was world changing. Speed in Morse code is measured in a specific way. Based on International Morse code, which is what I'm using throughout this discussion, if you send the word "PARIS" a dozen times in a minute and the next time starts right on the next minute, you officially sent Morse at 12 WPM. Looking inside the message of the word "PARIS", it's made up of a collection of dits and dahs. If a dit is one unit of time, then the letter "a", represented by dit-dah, is six units long when you include the spacing. In total, the word "PARIS", including the space after it, is exactly 50 units long. When you send at 12 WPM, you're effectively sending 600 dit units per minute, or ten units or bits per second, each lasting a tenth of a second. Unfortunately, there is not a one-to-one relationship between Morse speed and ASCII, the American Standard Code for Information Interchange, for a number of reasons. Firstly, Morse is made from symbols with varying lengths, where ASCII, the encoding that we really want to compare speeds with, has symbols with a fixed length. You cannot simply count symbols in both and compare their speeds, since communication speed is about what you send, how fast you send it, and how readable it is at the other end. Thanks to Aiden, AD8GM, who, inspired by my initial investigation, shared the idea and python code to encode Morse dits, dahs and spacing using a one for a dit, one-one-one for a dah, and zeros for spacing. This means that the letter "e" can be represented by "10" and the letter "t" by "1110". You can do this for the standard Morse word "PARIS" and end up with a combination of 50 zeros and ones, or exactly 50 bits. I've been extending the code that Aiden wrote to include other encoding systems. When I have something to show it will be on my GitHub page. However, using Aiden's idea, we gain the ability to directly compare sending Morse bits with ASCII bits, since they share the same zero and one encoding. If you use standard binary encoded ASCII, each letter takes up eight bits and the six characters for the word "PARIS", including the space, will take up 48 bits. Given that I just told you that the Morse version of the same message takes up 50 bits, you could now smile and say, see, ASCII is faster - wait, what? Yes, if you send the word "PARIS " using 8-bit binary coded ASCII it's two bits shorter than if you use Morse. Job done, roll the press, headline reads: "Morse is four percent slower than binary coded ASCII". Not so fast grasshopper. If you recall, American Morse code, the one that has Samuel Morse's name written all over it, was replaced by a different code, made by Friedrich Gerke which in turn was modified to become what we now know as International Morse code. Ask yourself, why did Gerke change the code? It turns out that one of the biggest issues with getting a message across an undersea cable was decoding the message at the other end. Let me give you an example, using American Morse, consider the encoding of "e", dit, and "o", dit-extra-space-dit and now try sending the word "seed" across a noisy line. Did you convey "seed", or was it "sod". In other words,

Foundations of Amateur Radio Morse code is a way for people to send information across long distances. The code we use today, made from dit and dah elements is nothing like the code demonstrated and attributed to Samuel Morse in 1837. Over years and with assistance from Professor of Chemistry Leonard Gail and Physicist Joseph Henry, then Professor of Literature, Samuel Morse, and mechanically minded Alfred Vail developed an electrical telegraph system that automatically moved a paper tape and used an electromagnet to pull a stylus into the paper and a spring to retract it, marking the paper with lines. The original system was only intended to transmit numbers, and combined with a dictionary, the operator could decode the message. The telegraph was able to send zig-zag and straight lines, transmitting the message "Successful experiment with telegraph September 4 1837". The system was enhanced to include letters, making it much more versatile. On the 6th of January 1838, across 4.8 km of wire, strung across a barn, the new design with letters and numbers was demonstrated. To optimise the enhanced version of the code, Alfred Vail went to his local newspaper in Morristown, New Jersey, to count the movable type he found in the compositor's type-cases, and assigned shorter sequences to the most common letters. You might think that this explains the distribution of the codes we see today, but you'd be wrong. The 1838 system used four different element lengths and varied the spacing inside a character. For example, the letter "o" was signified by two dits with a two unit space between them, where today it's represented by three dahs. The letter "p" was signified by five dits, today this represents the number "5", and the code didn't distinguish between "i" and "y", between "g" and "j", and between "s" and "z". A decade later and an ocean away in Germany, writer, journalist, and musician Friedrich Gerke created the Hamburg alphabet, based on the work by Vail and Morse, it standardised the length of the elements and spacing into what we use today, the dit and the dah. He changed about half of the characters and also incorporated four special German characters, the umlaut version of A, O and U and the CH sound - pronounced like the sound for the composer "Bach" or the Dutch name "Benschop" - not to be confused with the CH in child, or the CK in clock, or the SH sound in shop. It was different in other ways. For example, the letter "i" and "j" had the same code. The code was optimised to be more robust across undersea telegraph cables. I'll be coming back to that before we're done exploring, but not today. If you want to skip ahead, the term you're looking for is dispersion. Gerke's code was adopted in 1851 across Germany and Austria and it is known as Continental Morse code. By the time most of Gerke's code was adopted as the European Standard in 1865 as one of many agreements that mark the founding of the International Telegraph Union in Paris, only four sequences of the original 1838 code remained and only two of those, "e" and "h" were identical. Which means that although the idea that Morse code is based around English is often repeated, at this stage it's nothing more than a myth, which my previous word list and subsequent dictionary letter counts across over fifty languages confirm. I'll mention that given Gerke's German heritage, I also made a letter count from a modern German dictionary and one from 1901 and found that the letter distribution in those two are very similar with only the letter "s" and "t" swapped between position four and five in the popularity contest stakes. The German letter Top-5 is "enrts" and the "o" is the 16th most popular letter. Speaking of "o", one observation to make is that the new International Morse code contained the letter "o" as dah-dah-dah, it also contained the letter "p" as dit-dah-dah-dit. These two codes come from an 1849 telegraph code designed by physicist, inventor, engineer and astronomer Carl August von Steinheil. There is evidence suggesting that he invented a print telegraph and matching dot script in 1836, based around positive and negative pulses, rather than pulse duration. I'm purposely skipping over earlier telegraph systems built and used by Carl Friedrich Gauss, Wilhelm Edward Weber, and Steinheil, only because we're talking about Morse code, not the telegraph. The 1865 ITU standard for International Morse code includes several accented letters, symbols for semi-colon, exclamation mark, chevrons and several control codes and both normal and short forms for numbers which merge all the dahs in any digit into a single dah. Many of these codes are not part of the official standard today. I'll point out that over time, experienced telegraph operators learnt to decode dits and dahs based on sound alone, negating the need for paper. This translates directly into how we experience Morse in our hobby today, by tone only. There is a much more detailed explanation on h

Foundations of Amateur Radio Thanks to several high profile races we already know that sending Morse is faster than SMS. Recently I started digging into the underpinnings of Morse code to answer the question, "Can you send Morse faster than binary encoded ASCII?" Both ASCII, the American Standard Code for Information Interchange and Morse are techniques to encode information for electronic transmission. One is built for humans, the other for computers. To answer the question, which is faster, I set out to investigate. I'm using the 2009 ITU or International Telecommunications Union standard Morse for this. Morse is said to be optimised for sending messages in English. In Morse the letter "e", represented by "dit" is the quickest to send, the next is the letter "t", "dah", followed by "i", dit-dit, "a", dit-dah, "n", dah-dit, and "m", dah-dah. The underlying idea is that communication speed is increased by making the most common letter the fastest to send and so-on. Using a computer this is simple to test. I counted the letters of almost 400,000 words of my podcast and discovered that "e" is indeed the most common letter, the letter "t" is next, then "a", "o", and "i". Note that I said "letter". The most common character in my podcast is the "space", which in Morse takes seven dits to send. Also note that the Morse top-5 is "etian", the letter "o" is 14th on the list in terms of speed. In my podcast it's the fourth most popular letter, mind you, my name is "Onno", so you might think that is skewing the data. Not so much. If I use the combined works of Shakespeare, and given that it represents an older and less technical use of language, and doesn't feature my name, I figured it might have a different result. The top-5 in his words are "etoai", the letter "o" is the third most popular, and "space" still leads the charge, by nearly 3 times. I also had access to a listing of 850 job advertisements, yes, still looking, and the character distribution top-5 is "eotin", the letter "o" is the second most popular letter. Because I can, and I'm well, me, I converted the ITU Morse Code standard to text and counted the characters there too. The top-5 letters are "etion", but the full stop is a third more popular than the letter "e", mind you that might be because the people at the ITU still need to learn how to use a computer, seriously, storing documents inside the "Program Files" directory under the ITU_Admin user, what were you thinking? I digress. The "space" is still on top, nearly six times as common as the letter "e". As an aside, it's interesting to note that you cannot actually transmit the ITU Morse standard using standard Morse, since the document contains square brackets, a multiplication symbol, asterisks, a copyright symbol, percent signs, em-dashes, and both opening and closing quotation marks, none of which exist as valid symbols. Back to Morse. The definition has other peculiarities. For example the open parenthesis takes less time to send than the closing one, but you would think that they are equally common, given that they come in pairs. If you look at numbers, "5" takes the least amount to send, "0" the longest. In my podcast text "0" is a third more common than "1" and "9" is the least common. In Shakespeare, "9" is the most common, "8" the least, and in job listings, "0" and "2" go head-to-head, and both are four times as common as the number "7" which is the least common. All this to say that character distribution is clearly not consistent across different texts and Morse is built around more than the popularity of letters of the alphabet. For example, the difference between the left and right parenthesis is a dah at the end. If you know one of the characters, you know the other. The numerical digits follow a logical progression from all dits to all dahs between "0" and "9". In other words, the code appears to be designed with humans in mind. There are other idiosyncrasies. Most of the code builds in sequences, but there are gaps. If you visualise Morse as a tree, the letter "e" has two children, both starting with a dit, one followed by another dit, or dit-dit, the letter "i", and the other, followed by a dah, dit-dah, the letter "a". Similarly, the letter "t", a dah, has two children dah-dit, "n" and dah-dah, "m". This sequence can be built for many definitions, but not all. The letter "o", dah-dah-dah, has no direct children. There's no dah-dah-dah-dit or dah-dah-dah-dah sequence in Morse. The letter "u", dit-dit-dah has one child "f", dit-dit-dah-dit, but the combination dit-dit-dah-dah is not valid Morse. It's those missing combinations that led me to believe that Morse isn't as efficient as it could be and what originally led me to investigate the underpinnings of this language. I think it's fair to conclude at this point that Morse isn't strictly optimised for English, or if it is, a very small subset of the language. It has several eccentricities, not unlike the most popular computer key

Foundations of Amateur Radio If you've ever looked at Morse Code, you might be forgiven if you conclude that it appears to be a less than ideal way of getting information from point A to point B. The idea is simple, based on a set of rules, you translate characters, one at a time, into a series of dits and dahs, each spaced apart according to the separation between each element, each character and each word. The other day I came across a statement that asserted that you could send Morse faster than binary encoded ASCII letters. If you're not sure what that means, there are many different ways to encode information. In Morse, the letter "e" is the first character, represented by "dit", the letter "t" is the second character, represented by "dah". In ASCII, the American Standard Code for Information Interchange, the letter "e" is the 69th character, represented by 100 0101. The letter "t" is number 84 on the list, represented by 101 0100. A couple of things to observe. The order of the characters between Morse and ASCII are not the same. That doesn't really matter, as long as both the sender and receiver agree that they're using the same list. Another thing to notice is that in Morse, letters are encoded using dits and dahs and appropriate spacing. In ASCII, or technically, binary coded ASCII, the letters are encoded using zero and one. I'll also mention that there are plenty of other ways to encode information, EBCDIC or Extended Binary Coded Decimal Interchange Code was defined by IBM for its mainframe and mid-range computers. It's still in use today. In EBCDIC, the letter "e" is 133 and the letter "t" is 163. It was based around punched cards to ensure that hole punches were not too close together. It was designed for global use and can, for example, support Chinese, Japanese, Korean and Greek. Another encoding you might have heard of is UTF-16, which supports over a million different characters including all the emojis in use today. Before I continue, I must make a detour past the ITU or the International Telecommunications Union. The ITU has a standard, called "Recommendation M.1677-1", approved on the 3rd of October 2009, which defines International Morse code. I'm making that point because I'm going to dig deeper into Morse and it helps if we're talking about the same version of Morse. I have talked about many versions of Morse before, so I'll leave that alone, but I will point out a couple of things. The ITU defines 56 unique Morse sequences or characters. The obvious ones are the letters of the alphabet, the digits and several other characters like parentheses, quotes, question mark, full-stop, and comma, including the symbol in the middle of an email address, which it calls the "commercial at symbol" with a footnote telling us that the French General Committee on Terminology approved the term "arobase" in December 2002, but it seems that seven years isn't enough time to convince the ITU to update its own standard, mind you, the rest of the world, well, the English speaking part, calls it "at", the letter "a" with a circle around it, as in my email address, [email protected]. Another thing to note is that this standard is only available in English, Arabic, Chinese, French and Russian, so I'm not sure what the Spanish, Hindi, Portuguese, Bengali and Japanese communities, who represent a similar population size do for their Morse definitions. It's interesting to note that as part of its commitment to multilingualism, the ITU actually defines six official languages. Specifically, the "Spanish" version of the standard appears to be missing. There's other curious things. For example, the standard defines a special character called "accented e", though it doesn't describe which accent, given that there are four variants in French alone, I found at least seven versions and it completely ignores accents on the i, the c, the o, special character combinations like "sz" in German and "ij" in Dutch. This isn't to throw shade on Morse, it's to point out that it's an approximation of a language with odd variations. I'm also going to ignore capitalisation. In Morse there's none and in ASCII, there are definitions for both, capitalised and not. In addition to things you write in a message, there's also control codes. The ITU defines six specific Morse control codes. Things like "Understood", "Wait", and "Error". ASCII has those too. The first 31 codes in ASCII are reserved for controls like "linefeed", "carriage return", and "escape". There are other oddities. The ITU specifies that the control code "Invitation to transmit" is symbolised by dah-dit-dah. If you're familiar with Morse, you'll know that this is the same as the letter "k". The specification says that multiplication is dah-dit-dit-dah, which is the same as "x". There's also rules on how to signify percentages and fractions using dah-dit-dit-dit-dit-dah, the hyphen, as a separator. At this point I haven't even gotten close to exploring efficiency, but my cur

Foundations of Amateur Radio Have you ever made an international contact using amateur radio and used that towards tracking an award like for example the DXCC? If you're not familiar, it's an award for amateurs who make contact with at least 100 "distinct geographic and political entities". In 1935 the American Radio Relay League, or ARRL published an article by Clinton B. DeSoto, W1CBD, titled: "How to Count Countries Worked: A New DX Scoring System". In the article he asks: "Are Tasmania and Australia separate countries?" In case you're wondering, Tasmania has, at least in legal terms, been part of Australia since Federation in 1901. Not to be confused with New Zealand, a separate country over 4,000 kilometres to the east of Australia, Tasmania is the island at the south eastern tip of Australia. It was previously called the Colony of Tasmania, between 1856 and 1901 and before that it was called Van Diemen's Land between 1642 and 1856. Before then it was inhabited by the palawa people who lived there for about 42,000 years. They eventually became isolated after being cut off from the mainland by the Bass Strait when about 10,000 years ago sea levels rose due to the ice age coming to an end. In the last remaining local Aboriginal language 'palawa kani' it appears to have been called 'lutruwita' (/lu-tru-wee-ta/), but no living speakers of any of the original Tasmanian languages exist. As audio evidence, we have a few barely audible sounds spoken by Fanny Cochrane Smith on a wax record from 1899 on which she sang traditional songs. I'm mentioning this to illustrate that DeSoto asking the question: "Are Tasmania and Australia separate countries?" is, in my opinion, fundamentally misguided. More so because of an island, well, rock, Boundary Islet, that's split by a border, one half belonging to Victoria, the other half to Tasmania. Specifically, since 1825, the state of Victoria and the state of Tasmania share a land border thanks to a survey error made in 1801. If you're into Islands on the Air, or IOTA, it's part of the Hogan Island Group which for activation purposes is part of the Furneaux Group, which has IOTA designation OC-195. One point to make is that today the DXCC does not mention Tasmania, either as a separate entity, or as a deleted entity. It was removed from the DXCC in 1947. The DXCC list is pretty famous in amateur radio circles. It's not the only such list. I already mentioned the IOTA list which contains a list of islands and island groups and their IOTA designation. There's also a list of 40 groups of callsign prefixes called CQ zones, published in CQ magazine, and a list of IARU regions maintained by the International Amateur Radio Union. There's also an ITU zone list, maintained by the International Telecommunications Union. Each of these lists are essentially grouped collections with an attached label. The list of DXCC entities is copyrighted by the ARRL. If you want to use it for anything other than personal use you need to ask permission. In other words, if you write software that for example tracks amateur radio contacts and you make that software available for others to use, you officially need permission from the ARRL to use it to track a DXCC. If you're an amateur outside of the United States your peak body will need permission from the ARRL to issue any DXCC award. The ITU, the International Telecommunications Union is a United Nations specialised agency, part of our global community, owned by all humans. It peppers its content with copyright notices. The same is true for the International Amateur Radio Union, the IARU, the global representative body of all radio amateurs. It too peppers its content with copyright notices, even going so far as to add requirements that "(a)ny copy or portion must include a copyright notice" and that "(i)t is used for informational, non-commercial purposes only". Let me ask you a question. Can you achieve a DXCC without international cooperation? Of course not. If you are an American amateur and want to get an award for contacting 100 distinct geographic and political entities, you can only do so by making contacts outside the United States of America. As an Australian however, I have, according to the February 2022 version of the DXCC list, 340 countries to choose from, only one of which is the United States of America, and Alaska isn't part of the United States, apparently. It might appear that I'm singling out the ARRL, but that's not true. CQ Communications, Inc. owns the list of CQ Zones, the ITU owns the list of ITU zones, the IARU owns the list of IARU Regions, Islands On The Air Ltd. and the Radio Society of Great Britain own the IOTA list and Clinton B. DeSoto W1CBD became a silent key in 1949, his copyright expired in 1999. So, is grouping and labelling things sufficient to actually claim copyright? Can I claim copyright for all countries starting with the letter 'A' and calling it the 'Alpha Amateur Award'? My preliminary list for the 'A

Foundations of Amateur Radio In the earlier days of my career I worked in a computing centre at a university surrounded by people with different interests and experiences in computing. There were programmers, hardware engineers, technicians, sales people, administrators, educators, support staff, statisticians and even a librarian. There wasn't a lot of socialising or foosball, but every now and then we'd bump into each other in the lunchroom and talk about things that were not work related. During such conversations I learnt that people had all manner of interests outside their work, they were volunteer firefighters, or building their house, or active in the girl guides and any number of other unrelated pursuits and skills. That same is true for the people inside the hobby of amateur radio. I've met people who were submariners, tow-truck drivers, accountants, paramedics, radio astronomers, telco and broadcast engineers, doctors, IT people, lots of IT people, and plenty of other professions. As you might know, I'm self-employed. I am now acutely aware of mixing business with pleasure because not that long ago, every single time I met another person outside my field I'd get asked about some or other computer problem. Similarly I've witnessed medical professionals being asked about specific and personal medical issues and every time I experienced it or noticed it, a little part of me shied away from either telling people what I did or asking others for professional advice. Now before you think that I'm telling you not to talk about computers within earshot of me, that's not at all what this is about. It's about building an awareness that there are people in your community from all kinds of different backgrounds with different experiences, something which I've talked about many times before, but, and here's a new thing, some of those people do not want to give free professional advice, or be dragged kicking and screaming back into their day-job when they're out having fun. There's a difference between talking about what a virus is and asking about which computer to buy, a difference between talking about the neurological aspects of mushrooms and asking if someone can help you with deciding which medication to use. There's a difference between talking about radio telescopes and asking to access laboratory measuring equipment. If you're unsure where the line is, think of it in this way. If your mate is a plumber, it's one thing asking them what sand in your sink means and another thing entirely to ask them to dig up your backyard. I'm not telling you how to live your life, I'm asking you to be considerate of those around you who might have a skill set that you lack and need, whom you've met through the amateur community. An example of how you might navigate this process is to ask the person if it's appropriate to ask a specific question and to be prepared for hearing "No". Or you might be surprised and find that they're happy to help, to a point. I'd encourage you to be mindful of that point. In case you're wondering, nobody has been stepping on my toes and if you recently asked me a question, you haven't overstepped any lines. At this point you might be wondering what this has to do with amateur radio and why I'm talking about it now. The answer lies in the nature and evolution of our community. If you look at us as we were a century ago, like I did extensively when I discussed the evolving nature of the so-called "Amateur's Code", apparently written in 1923 by Lieut.-Commander Paul. M. Segal, you'll know that the community from last century is nothing like the community today. I'm sure that you agree that today we're not Gentlemanly, we're not beholden to the ARRL, and we're not all male, to name a few obvious changes and as a result the Amateur's code was updated, many times, to reflect our evolution. Those changes came about because people had ideas, had discussions, wrote things down and shared them. That's what this is. A mark on the page saying that I'd like our community to be mindful of the expectations made of the members of the community around us. Where are your boundaries and what did you do when someone stepped on them? I'm Onno VK6FLAB

Foundations of Amateur Radio The other weekend there was an amateur radio contest on. Not surprising if you realise that's true for most weekends. For a change, I knew about this contest before it started, because I missed out a year ago, so I did the smart thing to add it to my diary with an alert a month out. In this particular contest there's points to be made by being a so-called roving station, that is, one that moves around during the contest and in the past that's how I've participated and had lots of fun. So the die was cast and a plan was concocted. Being a rover meant that I would be outfitting my car with my radio. It's been out of the car for several years, taken out when we had the transmission replaced, and never actually returned. I started making lists of everything I'd need, including learning that you can use a bench top power supply to charge a 12V battery if your trusty charger has let the smoke out. I went hunting for the cable that connects the front of the radio to the back and realised that it was still in the car, so I could cross that off my checklist. I decided for the first time that realistically I could log using paper and save myself the heartache of finding a computer with a suitable battery and matching software, especially since I'd be operating with low power so making a gazillion contacts wasn't going to be a problem. I went to the shops to get some road food, in my case I like to bring water and oatmeal bars which keep me going through the night. One change was that the contest only ran for 24 hours, leaving less time for sleep. I found my portable antenna tuner, plugged everything in, configured the radio for remote tuning, and tested it all on the bench in my shack. In further preparation I packed my food, got a headlamp out, spare batteries, a pen and a spare, a ring binder for logging and my wristwatch to keep track of logging times. The day before the contest I parked the car in the sun, extracted all the cables from behind the backseat, installed the radio, the battery, the head, the suction mount, the microphone, the speaker, the antenna tuner and antenna mount, and got everything where I wanted it. In between rain showers I located the ropes I use to keep the antenna from breaking off the car when I'm driving, set it all up to length after hunting through the garage to find my multi-tap antenna to suit. Strapped that all together to the handhold in the cabin with a Velcro strap and called it a day. The next morning I drove to my first activation location, installed the antenna on the 40m band, turned on the radio, tuned it, and called CQ Contest. Made my first contact about six minutes after I started. I was excited. Drove to the next location, made the next contact six minutes later. On a roll I drove to my third spot, where things came unstuck. I spent the next two hours getting nothing. I changed both location and band, setting the antenna to 15m and after initially tuning once I couldn't get it to tune again. I spent an hour trying. Given that I wasn't far from home, I went back for a break and to pick up one piece of equipment that I should have packed when I started, my antenna analyser. I tested the antenna and for reasons I still don't understand, it was only resonant on 19 MHz, not much good if you're trying to tune somewhere on 21 MHz. I moved back to my first spot and changed to the 10m band. Three hours to the minute after my second contact, I made another one, this one outside the state. By this time it had been raining steadily for four hours, despite a forecast of little or no rain. The car was stuffy, no way to open the window and stay dry, no contacts, no fun. I asked myself why I was doing this and decided that I'd learnt a valuable lesson and packed up and went home. I did go out later in the afternoon to provide some moral support to a friend who had made double the three contacts I'd made, but by dusk we had both had enough. My lesson for this week? Test the antenna before you go out and bring your analyser. I must add that I've been contesting for years and I've always packed the analyser but never ever needed it. This time I didn't and Murphy let me know that anything that can happen, will. It might sound like a dejected wet cat story, but I learnt a valuable lesson and now I've got another challenge, to discover just why my trusty antenna stopped working. If I do find out I'll let you know. What unexpected lessons have you learnt of late? I'm Onno VK6FLAB

Foundations of Amateur Radio During the week, prompted by a protest on popular social media site Reddit, I rediscovered that there are other places to spend time. It sounds absurd now, but until then much of my social interaction with the world was via a single online presence. This didn't happen overnight. Over the years more and more of my time was spent on Reddit engaging with other humans around topics of my interest, amateur radio being one of them. As you might know, I'm the host of a weekly net, F-troop. It's an on-air radio discussion for new and returning amateurs that's been running since 2011 and you can join in every Saturday for an hour at midnight UTC. In addition to the net, there's an online component. It captures items of interest shared during the on-air conversation. It's intended to stop the need to read out web addresses on-air, create a historic record of the things we talk about and allow people who are not yet amateurs to explore the kinds of things that capture our interest. Since 2014, F-troop online was a website that I maintained. After the announced demise of the service in 2020 I explored dozens of alternatives and landed on the idea to move to Reddit, which happened in March of 2021. At the time of selecting Reddit as the successor to the website, I wanted to create a space where anyone could add content and discuss it, rather than rely on a single individual, me, to update the website every time something was mentioned. During the net these days you'll often hear me ask a person to post that on Reddit. This to illustrate, at a small scale, how the F-troop community shares its knowledge with each other and the wider community. With the realisation that there are other places to spend time, comes an uneasy feeling about how we build our online communities, and how resilient they really are. Before the Internet our amateur radio community talked on-air, or in person at club meetings, or shared their interests in a magazine, or wrote letters. Today we congregate online in many different communities. If one of those fails or loses favour, finding those people elsewhere can be challenging, especially if those communities prefer anonymity. For quite some time now I have been thinking about how to build a radio amateur specific online community. The issues to surface, address and overcome are wide and varied. I created a list ... hands up if you're surprised ... I will point out that I'm sure it's incomplete, your additions and comments are welcome. Funding is the first item to consider. All of this costs time and money. Amateurs are notorious for their deep pockets and short arms, but they're no different from much of humanity. If this community needs to endure, it needs to be financially sustainable from the outset. Authentication and Identity is the next priority. If it's for amateurs, how do you verify and enforce that and what happens if an amateur decides not to renew their callsign, do they stop being an amateur? Should this community be anonymous or not? Moderation and Content is next on the list. What types of content are "permitted"? What is the process to regulate and enforce it? Is this forum public and accessible via a search engine, or private? Can people who are not yet amateurs benefit from the community and use it to learn? How do you set rules of conduct and how do you update them? How do you deal with rule infractions and how do you scale that? Who is this for? Is it decentralised across each callsign prefix, across a DXCC entity, or based on some other selection criteria? Can you have more than one account, or only one per person, or one per callsign? What about machine accounts, like a local beacon, repeater, solar battery, radio link, propagation skimmer or other equipment? What about bots and APIs? If that doesn't mean anything, a bot, short for robot, is a piece of software that can do things, like mark content as being Not Safe For Work, or NSFW, or it could enforce rules, or look-up callsigns, or share the latest propagation forecast or check for duplicates, scale an image, convert Morse code, check for malicious links, or anything you might want in an online community. The way a program like a bot, or a mobile client, or a screen reader, or a desktop application talks to the community is using an API, or an Application Programming Interface. Incidentally, the protest at Reddit is about starting to charge for access to the API, something which will immediately affect software developers and eventually the entire Reddit community, even if many don't yet realise this. What about system backups and availability? How seriously are we taking this community? Is there going to be a Service Level Agreement, or are we going to run it on a best-effort basis? How long is it acceptable for your community to be inaccessible? What about content archiving and ageing? Do we keep everything forever, do we have an archive policy? What happens if a topic that's permitted one y

Foundations of Amateur Radio Our hobby has been around for over a century. The Wireless Institute of Australia, or WIA, is the oldest amateur association on the globe, having just marked 113 years since formation. The American Radio Relay League, or ARRL, is four years younger, founded in 1914. I'm mentioning these two associations because they documented their journey through many of the years since foundation. The ARRL has published QST magazine since 1915 and the WIA has published Amateur Radio Magazine since 1933. Before the Internet and the Digital Library of Amateur Radio and Communications, magazines like QST and AR Magazine were some ways of documenting and archiving achievements across our community. If you find my professional biography online, you'll read: Experienced polyglot IT professional, software developer, trouble shooter, researcher, public speaker, educator, writer and publisher, founder and small business owner, podcaster, and licensed radio amateur. It's fair to say that I've done a great many things across the technology arena. I have been writing software since before I was a teenager. At the time we used words like freeware and shareware, we copied lines of BASIC from the pages of the latest computer magazine, or recorded the TV teletext signal to access a programme. I recall typing pages of hexadecimal codes and running the result. Very satisfying to make sprites running across your screen. In the decades since, technology has moved on. I've had a front-row seat to see that evolution happen. I've also witnessed one of the victims of the 1980's computer craze, the fundamental obliteration of its history. Much has been lost, either physically by destruction or disposal of boxes of magazines or the deterioration of audio cassette tapes once used to store software. I hold a Guinness World Record of Endurance Computing, set in 1989 during the Hobby Computer Club days, but you'll not find it anywhere other than a copy of the Dutch World Records that might be somewhere in my garage, or not. The twice-daily magazine we published over the three days of the event, Elephant News, was lost to time. I'm mentioning this because this loss is not limited to the 1980's, it's happening here, today. As our hobby evolves into the software realm, we need to consider just how that legacy continues beyond our own lifetime. For example, we have lost access to the fundamentals of how exactly HAM DRM works, we've lost the source for VK Contest Logger to name another, and the collected designs by so-called antenna guru L.B. Cebik W4RNL (SK) are scattered around the Internet, but as far as I know, none of it is complete. Fortunately we have tools at our disposal to keep our history. As I mentioned, the Digital Library of Amateur Radio and Communications or DLARC is an Internet Archive project to catalogue and store current and historic amateur media. In the 30 weeks since starting in October 2022, it now has 75,000 items and continues to grow under the expert stewardship of Program Manager, Special Collections, Kay, K6KJN. The DLARC is not the only tool at our disposal and documentation isn't the only way we share technology in our hobby. More and more of what we do is based around software. We use programs to process signals, to generate and receive different modes, to create logs, to model antennas, to log propagation, and that list grows daily. One of the most significant changes in software since my childhood is that of the introduction of Open Source Software in 1998. I've spoken about this several times before and I recently pointed at Not1MM as an example of an Open Source contest logger, but that is not the only project available. If you visit GitHub.com and search for "amateur radio", you'll discover over a thousand projects showing a healthy ecosystem of activity from people like Daniel EA4GPZ who shared gr-satellites, a collection of telemetry decoders that support many different amateur satellites. You'll find APRSdroid by Georg D01GL, which allows radio amateurs to view and report locations using the APRS network. There's an Arduino based rotator interface by Anthony K3NG, an advanced ham radio logger called CQRLOG by Petr OK2CQR, a radio modem by Dan KF7IJB, remoteAudio by Tobias DH1TW, and the list goes on. I must also point out that I'm only naming the person behind the repository because as is the whole point of Open Source software, anyone can contribute in different ways. You can make a copy of the source-code and write your own version, a so-called fork, or you can create trouble-tickets to explain a bug or problem, there's ways of contributing fixes and ideas and all of that can be done by anyone anywhere. Many of the projects I've just shared are a combination of years of effort by many different people. And that is the point of this conversation. Amateur Radio is a collaborative affair. We learn and share from the experience of others. We document how we built a schematic, or an antenna