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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. Di

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 lett

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

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 n

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 cq@vk6flab.com 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,

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 th

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

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 blott

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 doze

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

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

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