Foundations of Amateur Radio

Foundations of Amateur Radio The other day I was stuck in traffic behind a vehicle proudly proclaiming that it was "electric". I'd seen the model before, just never connected it with being available as an EV. I wondered how many other cars on the road turned out to have added an "electric" option to their line-up and how that evolution had just quietly, inexorably occurred. It started me thinking about the nature of the driving experience and what it would be like for someone who has never seen a petrol, or other fossil fuel burning vehicle, and what driver education might do to incorporate that. In my teens I first sat on a hotted up moped belonging to a friend, I was old enough to be legal, whilst he wasn't, so I got to ride his bike to school with him on the back, win-win for both. Later on, I learned to drive a car with a manual gearbox and as interest took me, I learned to drive a double clutch gearbox and got my heavy rigid truck license. I also learned to fly a plane, but that's besides the point. Stuck in rush-hour traffic, such as it is in Perth, it made me think about amateur radio licensing and education. Specifically, how do we incorporate change? When I was first licensed, my education included consideration for analogue television interference, including pictures of different screen patterns, their causes and remedies. Three years after I got licensed, almost to the day, the last analogue television transmitter in Australia was switched off on 10 December 2013, 57 years after the first transmissions started. While I retain little, if any, of the now, let's call it, esoteric information associated with that, it made me consider a wider picture in relation to the process of amateur radio education. New amateurs today are unlikely to be asked about analogue television interference, let alone be subjected to questions in their exam. Fair enough, information changes, evolves, becomes superseded or expires, and as a side-effect, I have some brain cells dedicated to analogue television, PAL, 625 lines total, 576 visible, horizontal and vertical synchronisation, white noise, you get the idea. As an aside, 78 on a turntable indicates a speed reserved for shellac records until the 1950s, seeing that we're dropping arcane knowledge. Oh, means NOP on a 6502, in case you're wondering. Although I don't have a specific list of what is currently being taught .. more on that in a moment .. I daresay that newly minted amateurs have a curriculum that has evolved with technology and legal requirements over the past 15 years. A tangible example is the fact that the Foundation Class in Australia is now permitted to use digital modes, something that changed after I was licensed, when on 21 September 2019, the regulator amended the Amateur License Conditions Determination, known locally as the LCD, with immediate effect. The point being that over time things change and education changes with it. This is all as expected. Here's my question. What about the rest of the community? What happens to someone who has been licensed for a decade, a generation, or more? Are they expected to gain these skills by osmosis or self-education? Should this process be dictated by the regulator, or should this be a community effort to bring everyone into the same decade? Should we revise how we educate our amateurs and make the education skill-set technology agnostic, should we be less prescriptive with the license, or should it achieve something else? One example in this space is an initiative called the Ham Challenge, which you can discover at hamchallenge.org. In case it sounds vaguely familiar, I've talked about this before. It's a list of 52 activities that you can take on to broaden your horizons and explore different aspects of our hobby. In its first year, I'm looking forward to seeing how it evolves. Is this the kind of self-training that we might encourage, or is there another way to achieve this? Is this something that occurs elsewhere in society and if so, how has that been addressed? I know for example in ICT there are endless certification courses, which I have to confess are in my professional opinion absolutely counterproductive, serving only to entrench vendor lock-in, not something that I think benefits the amateur community. I mentioned curriculum a moment ago. Another approach is to attend a licensing course and participate as part of your own self-education. Of course this will require cooperation from the educators, and we'd need to come up with some idea of how this might be useful. Is this something that benefits from attendance every five years, every decade, more, less? As a bonus side-effect, it will introduce new amateurs to old ones, and vice versa, perhaps facilitating a new resurgence of Elmering, or mentorship, that previously has been the hallmark of our community. Over the decade and a half or so that I've been licensed and writing weekly articles about the hobby and our community, I've made a conscious effort to keep up to date, to learn new skills, to share what I've learnt, to actively explore what I need to learn more about and to share that journey with you. I realise that this is not a universal experience. For some their amateur license sits in a drawer gathering dust together with their first aid certificate and their first runner-up prize for something that for a minute and a half caught their attention years ago. For most of us the reality lies somewhere in between. For many, the amateur experience is one of playing on air and getting delight from the doing and participating. There are those who go out and become teachers, those who sit on boards, those who run clubs and those who get on the local repeater once a week. It takes all of us to make this community and my thoughts are not intended to stop that enjoyment and experience. I'm trying to discover how we build a resilient community, one that is sustainable in a world of continuous and rapid change. I'm Onno VK6FLAB

Foundations of Amateur Radio Recently I spent some quality time digging into the origins of a word in common use. In doing so, I contacted the Postal Museum in the United Kingdom and received a lovely reply that included a photo of a document in their archive. The document, a Post Office Circular from Friday, December 30, 1904, number 1641, introduces a new service offered by the Post Office. Let me read to you what it says, and I quote: "Telegrams to and from Ships by Wireless Telegraphy. "(To be noted at Telegraph Offices only.) "With the present Circular is enclosed a list showing the wireless telegraph stations in the United Kingdom worked on the Marconi Company's system, and the hours up to which telegrams can be received at those stations for transmission by wireless telegraphy to certain ships fitted with Marconi apparatus. By another notice in this Circular, Postmasters and others concerned are requested to enter the names of the stations in the Code Book with the necessary particulars. Ships will be issued for insertion in the Post Office Guide. "On and from the 1st January, 1905, Telegrams may be accepted from the public on the following conditions:- "Subject to the Inland Regulations with regard to counting, the charge, which must be prepaid in the usual way by means of stamps, will be at the rate of 6 1/2d. [six-and-a-half pence] a word, with a minimum of 6s. 6d. [six-and-a-half shillings] per telegram. "The name of the wireless station will in each case pass as one word in the address. "The word 'Radio,' which is not charged for, should be telegraphed in the Service Instructions." When I read that, it made the hair stand up on the back of my neck. The introduction of a Wireless Telegram service, under the service heading of "Radio", with a photo of the actual document that introduced it into the world. I also learned that there's a dozen pennies in a shilling and over the years before decimalisation in 1971, the composition of coins changed, which made converting this into today's money interesting. As an aside, the Royal Society has a wonderful article: "The science of money: Isaac Newton's mastering of the Mint" Back to radio, this is 1904 bleeding edge technology and it's priced accordingly. The starting price for a radio telegram on new years day 1905: six bob and six; or three florin and sixpence; or a crown, a bob and a tanner; is worth just over 34 Great British Pounds today, that's just on 45 US Dollars, or nearly 69 Australian Dollars. That's the minimum price. The price per word, sixpence and halfpenny [sixpence hayp-ny] is just over 2 Great British Pounds today, nearly 4 US Dollars or almost 6 Australian Dollars. Compare that to the price of SMS, which started at about 21 cents here in Australia, today it's about 3 cents per message of 160 characters. This seems like a lucrative business to be in, but I digress, again. From my current, and ongoing research, it appears that until this point, the early 1900's, the word "radio" was always accompanied by another word, for example in this context, "radio telegraphy", another combination of the day is "radio active", as well as "radio tellurium", which today we know as polonium. Moving on, the response I received from the Postal Museum included other gems, including a reference to the "1904 Wireless Telegraphy Act", from the 15th of August, 1904, where I found something fascinating, from Section 2 paragraph 1: "Where the applicant for a licence proves to the satisfaction of the Postmaster-General that the sole object of obtaining the license is to enable him to conduct experiments in wireless telegraphy, a license for that purpose shall be granted, subject to such special terms, conditions and restrictions as the Postmaster-General may think proper, but shall not be subject to any rent or royalty." I think that's the birth of amateur radio licensing in the United Kingdom, right there. As an aside, because I cannot help myself, the definition for the expression "wireless telegraphy", is pretty interesting too, reminding me of a quote, variations going back to at least 1866, incorrectly attributed to Einstein that goes something like this: You see, wire telegraph is a kind of very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, and they receive them there. The only difference is that there is no cat. Seems that the drafters of the "1904 Wireless Telegraphy Act" had the same thing in mind when they wrote: "The expression 'wireless telegraphy' means any system of communication by telegraph as defined in the Telegraph Acts, 1863 to 1904, without the aid of any wire connecting the points from and at which the messages or other communications are sent and received" Now, as I said, I'm still working on this, because the word "radio" as a concept had to have been conceived before the Post Office Circular was written, printed and published. It might transpire that this was the brainchild of a single individual, or it might be that this was a term whose time had arrived, or this might not be the first occurrence of the word "radio" as a concept. Today we think nothing of it when we use it to turn on the radio, listen to, or talk on the radio, radio for help, break radio silence, and plenty of other uses of this now ubiquitous word. Thanks again to the Postal Museum for finding and photographing the Post Office Circular for the 30th of December 1904, which at this stage appears to be the first occurrence of the word "radio" on its own, and for referring me to the 1904 Wireless Telegraphy act which appears to be the birth of "amateur radio" in the United Kingdom. You can find both documents on my project site at vk6flab.com. I should also mention the brave individuals who took the time to share with me how to refer to Old British Money, any mistakes are all mine. I'm Onno VK6FLAB

Foundations of Amateur Radio If you use a word often enough it starts to lose its meaning. The other day, during breakfast, well, coffee, whilst playing one of our start-the-day with a smile word games, the word "RADIO" turned up. I grinned and pointed out that this was my favourite word, to which my partner mentioned that in Italian, it's referred to as "La Radio", which made us both wonder where it actually came from, did the Italian language import the word, or export it, given that Guglielmo Marconi was Italian? A quick search advised us that it came from Latin, radius, meaning "spoke of a wheel", "beam of light" or "ray". Fully enlightened we finished our coffee and got on with our day .. except I couldn't stop thinking about this. Having recently spent some quality time looking into the history of the RF Circulator, I figured searching the patent records might be a solid way to get some handle on where this word "radio" came from. Initially Google Patent search unearths the oldest as being from 1996, not very helpful. Adding 1900 as the end date filter turns up a radio cabinet patent with a filing date of 1833, except that it was published and granted in 1931, which is confirmed by the patent itself. This level of corruption in the data affects at least a dozen patents, but I daresay that there's plenty more like that. 1857 turns up a patent with the word "broadcasting", in the context of "broadcasting guano", so, nothing much has changed in nearly 170 years, but I digress. Adding quotes to the search term unearths a patent from 1861, apparently iron roads, locomotives, large slopes and small radio curves relates to the other meaning of the word radius, in Spanish. 1863 gives us ruffle stitching, "made upon the radio", but the patent is so corrupt that it's pretty much unreadable. 1871 unearths an electromagnetic engine, but the text has so much gibberish that I suspect that the word "radio" is a happy accident. 1873 shows us a "Wireless signalling system", bingo, the patent shows us transmitter and receiver circuits, antennas, messages and frequencies and a whole bunch of relevant radio information, except that the date on the patent itself is 1919. And you wonder why people argue about who invented what when? I'll spare you the gas apparatus, petrol lamps with cigar cutter, running gear for vehicles and bounce to 1897, "Method of and apparatus for converting x-rays into light for photographic purposes", the first occurrence of "radio", in the form of "radiograph", complete with pictures of the bones of a hand drawn meticulously from presumably an x-ray. I confess I'm not convinced. Using the United States Patent and Trademark Office search for the word radio gives you 54,688 pages with 2.7 million records, ordered in reverse chronological order with no way to skip to the last page. The World Intellectual Property Organisation finds the same Spanish iron paths patents, but unearths "A Differential Arrangement for Radio Controlled Race Cars" from 1900, but inside we discover it's really from 1979. Seems this level of corruption is endemic in the patent field, wonder who's benefiting from this misinformation? Meanwhile, still looking, I discovered the Oxford English Dictionary, which claims that the earliest known use of the word "radio" is in the 1900's, but the earliest evidence is from 1907 in a writing by "L. De Forest", but you are granted the privilege of paying them to actually see that evidence .. really? On 18 July 1907, Lee de Forest, made the first ship-to-shore transmissions by radiotelephone, which adds some credence to the claim, but I have to tell you, I'm not particularly convinced. Taking a different approach, starting at Guglielmo Marconi, his first efforts in 1894 showed the wireless activation of a bell on the other side of the room. Six months later he managed to cross 3 kilometres realising that this could become capable of longer distances. The Italian Ministry of Post and Telegraphs didn't respond to his application for funding, so in 1896, at the age of 21, moving to Great Britain, he arrived in Dover where the customs officer opened his case to find various apparatus, which were destroyed because they could be a bomb. Lodging a patent "Improvements in Transmitting Electrical impulses and Signals, and in Apparatus therefor", was the first patent for a communication system on radio waves. It was granted a year later. One problem. It doesn't have the word "radio" in it, instead it talks about "a Hertz radiator", so close. So, we've narrowed it down to somewhere between 1896 and 1907, that's an 11 year window. Some observations. De Forest founded a company called "the Radio Telephone And Telegraph Company". It's unclear exactly when this happened, it collapsed in 1909 and was founded after disagreement with management of his previous company, apparently on 28 November 1906. A quick aside, apparently in 1881, Alexander Graham Bell used the word radiophone for the first time, which he used to refer to a system that used light to transmit wirelessly, he also referred to it as a photophone. You could argue that because light and radio are the same thing, this is the first legitimate use of the word "radio" in the context of communication, but I'm not buying it. I'll leave you with the discovery that on 30 December 1904, the British Post Office published a "Post Office Circular" with the instructions to use the word "Radio" in the service instructions, think of it as the metadata associated with a telegram. This information has been repeated often without evidence. If you're keen, the Postal Museum is located in Phoenix Place, London. I've contacted them to see if that particular Circular is in their possession. Amazingly the "Post Office Circulars" have been digitised between 1666 and 1899. So close, but no cigar, that said, I looked for the elusive Volume 7 of the set to see if there were any straggling references to "radio", but couldn't confirm this. The Postal Museum Catalogue returns plenty of early references to radio, but it's hard to tell what's real and what's written after the fact. Anyone know of any research grants that will allow me to dig into this on-site, feel free to get in touch, oh, a bed would be good too .. I think this might take a while. At the moment, the best I have is an uncorroborated "30 December 1904" for the origin of the word "Radio", in English, in other words, it was imported into Italian. No sign of Marconi, Bell, or De Forest. I'm Onno VK6FLAB

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

Foundations of Amateur Radio The other day I saw a post by fellow amateur Gary N8DMT who mentioned an "RF circulator" and a PlutoSDR in the same sentence. Amplified by a response from a fellow Aussie Electronics Engineer, "ozeng", who helpfully added a link to a Wikipedia article about circulators, it finally twigged that I had such a gadget in my possession and for the first time I realised how I might use it. Now, before I continue, I'll preface this with a disclaimer, this is a hand-wavy description of what this very interesting device does. "ozeng" calls it "Absolute witchcraft." and that's an apt description if ever I've heard one. Imagine for a moment a radio with separate transmitter and receiver connectors, attached to the same antenna using a T-piece, as-in, there's a run of coax coming from each connector, joined together with a T-piece, which in turn is connected to an antenna. The aim of this, don't do this at home contraption, is to avoid the need for two antennas, but, and it's a big one, doing this will very likely destroy your receiver the moment you transmit for the first time, because likely half the transmission will go to the antenna, while the other half makes its way to the receiver, which is not going to be something you want to happen, unless you like the smell of magic smoke. You might think that adding an attenuator, something that reduces the power on the receive port would help. Well, yes, it would, but as a side-effect, it would also reduce the signal coming from the antenna. At that point you'll decide you need a switch. Initially you might switch this manually, but that's a pain if you're wanting to transmit and receive continuously and need to remember in which position the switch is in. The next step is to use an electronic switch, like a relay. It can trigger based on some signal from the radio when it's transmitting and turn off the receive path during a transmission. This raises an issue with delay. Do you trigger just before you hit the PTT, as-in, time-travel, or do you delay the transmitter until after the relay has switched, which will cut off the beginning of your transmission? You'll likely have heard this kind of issue when listening to a station using an external amplifier. Their signal either jumps from low power to high power after they key up, or you miss the beginning of their callsign. Not to mention that if you get the delay wrong, you blow up the receiver, fun for people watching, not so much for the equipment owner. Even if you get the timing right, you cannot transmit and receive at the same time. Of course an obvious solution is to have two antennas, but soon you'll discover that when you're transmitting and receiving on the same frequency, even using two antennas, you'll have the exact same issues. It's why the local 10m repeater here in Perth, VK6RHF, has the transmitter in one location and a receiver 12 km away, connected to each other via a 70cm radio link. Other solutions in this space are cavity filters, duplexers and diplexers. These all require that the transmit and receive frequencies are different and the equipment is generally tuned to a specific pair of frequencies. Physically cavity filters can be massive, not to mention fragile. So, solving the issue of having a transmitter and receiver together on the same frequency is one that is challenging to say the least. It's a common issue, think about mobile phones, satellites, broadcast transmitters, and even your own amateur radio station. An RF circulator is a device that solves this in an extremely elegant way. For starters, it's a passive device, which means that you don't need to power it, there's no moving parts, no switches, no delays, no external controls, it's a box, generally with three sockets or ports, though versions exist with more. At a basic level, it works like this. A signal inserted into port one, will only come out of port two. Similarly, a signal into port two, will only come out of port three and finally, a signal into port three, will only come out of port one. Think of it as a one way roundabout. How is this useful you might ask. I'll illustrate by plugging in three things, connect port one to an antenna, port two to a receiver and port three, a transmitter. When you transmit into port three, the signal only goes to the antenna, leaving the receiver safe and happy. Similarly, any antenna signal will only go to the receiver. So, how does this work? Remember, hand-wavy. Essentially, it's based on the idea that radio waves travelling in one direction combine and waves travelling in the opposite direction cancel. Different types of circulators achieve this in different ways and come in different sizes as a result. The RF circulator I have is roughly 60 mm square, 30 mm thick, weighing in at most of half a kilogram and as far as I know, intended for operation around 850 MHz. If I recall correctly, it came out of a CDMA mobile phone tower. The parameters that describe an RF circulator are the frequency range, the insertion loss, or how much signal gets lost getting from port one to port two, the isolation, or how much signal leaks between port one and port three and a couple of others. Hopefully I'll be able to use a NanoVNA, or PlutoSDR to get a sense of what these values are and confirm the frequency range. Now, if that doesn't blow your mind, wait until I tell you about the two hundred year history that accompanies it. I'm Onno VK6FLAB

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

Foundations of Amateur Radio The other day I went on my first POTA or Parks On The Air adventure, this time I was on my own. If you recall, my power company announced yet another planned network outage and I felt that I could use this time without electricity to my benefit, for a change. As is traditional, I did all the prior planning to prevent pretty poor performance. I made a list, checked that all the items on the list were in my kit, packed the kit days before, put it all ready to go in the hallway the night before, packed the car on the day and set out on my adventure. I will confess that I was slightly more sweaty than anticipated when I set off because the umbrella in the boot of my car has a nasty and recurring habit of getting in the way, specifically it stops things from getting pushed right to the full depth of the boot. Mind you, it wasn't until I started getting agitated that I realised that it wasn't the umbrella's fault entirely this time, since as it turns out, the folding chair that I was attempting to jam in place doesn't actually fit longways into the boot. Anyhoo, I set off and visited the local petrol station. I was not prepared for a customer to spend 15 minutes dribbling the last bit of diesel into their pretend Sports Utility Vehicle, but he looked like he was up for a fight, so I smiled sweetly and waited for him to pay and move his box on wheels. After paying for my own fuel and driving off, the pressure in my bladder had gotten beyond the "cross your legs and hope for the best" stages and I swiftly made my way to the nearest shopping complex where a local pharmacist helpfully told me that there were no toilets in the building and that the local hotel or fast food joint were the place to relieve the pressure. One problem .. they were both closed. At this point I was in pain, and discovered that I couldn't read the screen on my mobile phone in the lovely sunlight, because it was set to battery saving mode, since my charger was at home where the power was out. After disabling the battery saving mode I opened the local public toilet map shortcut on my phone, and discovered that fortunately the shortcut still worked, opening up my default browser, which suddenly didn't want to display a map. Copied the URL to another browser, still in pain, finally a map. Click on the nearest icon and it navigates me there from Darwin, or over 4,000 km from where I actually am. Luckily it has the GPS location which I copy and then paste into my mapping app, and I can finally navigate to the nearest toilet. Several comment worthy navigation moves later, I drive into the car park, lock the car, painfully shuffle to the building, do my business in the very clean facilities and then decide that I should just stop, sit, and take a breath. So, I get in the car and discover that my partner was right when they heaped scorn on our newly acquired thermos cup. It really does hurt your nose when you try to drink from it and the sharp edges in your mouth do nothing to make the experience joyful. Meanwhile there's some trucks moving around in the car park and a guy walks up to the car to ask me if I can move because they want to move a third, or was it forth, truck into the space. I swallow my sip of restorative coffee, wipe the now wet bridge of my nose, and move the car, only to be blocked from leaving the exit thanks to the slowest reversing truck I've ever encountered, one who then proceeds to sit at the next intersection for five minutes without indicating where it was going. Are we having fun yet? I finally made my way to the main road where I attempt to calm my nerves with the help of a Morse code edition of my podcast. It's been the only exposure I've had to Morse for way too long. This accompanies me to my first destination, breakfast. I'm going to skip past the drivers in the centre lane driving at 10 km per hour below the posted speed limit, or the ones who think that jumping out of a side street in front of you is normal and safe driving practice. At every traffic light I celebrate the pause with a sip from my coffee and a furtive wipe of my nose which is being assaulted by the lid of the cup. I arrive at my breakfast destination and fear the worst. Their car park is almost empty. I've never seen it this quiet and I didn't check to confirm that they were open, or not. I look at my map application and remember to turn my phone back to battery saving mode. According to the Internet, my cafe is open, so I cross my fingers and get out of the car. To my delight, they are absolutely open, make me a lovely breakfast and provide the needful for lunch too .. I have a big day planned after all. After enjoying breakfast and hot chocolate, with two marshmallows, I get back in the car and navigate to my planned set-up location. As I drive into the park I notice something that I hadn't the last time I was here. I'm descending, as-in, the deeper into the park I go, the more I go downhill. That in and of itself isn't a cause for concern, were it not for the fact that the local repeaters are on the hilltops that overlook the city and I'm several hills inland and travelling into a valley. I'm keeping my eyes open for side roads and alternatives, but gamely proceed to the formal entrance of the park, where I pay my $17 to have a car with a maximum of 12 passengers enter the National Park. I drive to the location I have planned and discover that there's a car park quite close to the gazebo I've earmarked, so I park there. I figure that before I get all set-up in the gazebo for a day of radio, I should first check what I can learn from where I'm parked, especially since I'll need to pull the gear out of the car either way. Before I get out of the car, I attempt to mark my actual location on the map, only to discover that there's no mobile phone coverage, so much for using Echolink as a fallback. I pull out the folding table which neatly fits next to the car, dig out the coax from the boot and lead it out the passenger door. The other end is connected to the boot-lip mount that has been there for years. In case of failure I did bring a magnetic base, but I'm optimistic. I remove the HF and VHF multi-band antennas from their storage spot, taped to the driver side rear passenger roof grab handle and pull out the previously errant folding chair. All is going well. I pull out the spare coax and my anxiety spikes a little, this is what I think might be what causes me to come unstuck. It's a 10 meter or so length of coax, it's untested, terminated with BNC and I'm concerned that I didn't bring enough adaptors beyond the BNC to PL259 and the SO239 barrel I packed hastily the night before. I push away my fear, since I'm not needing this right now and continue to unpack the radio, noticing that to my immense relief, the knobs are still attached, set it all up, pull the power cable from the 12 Volt, 80 Amp hour AGM Deep Cycle battery, "ideal for 4WD, caravan and camping trailers", which I bought four years ago to power my dash cams and radio. It's automatically charged by a 360 Watt DC to DC converter that's connected to the alternator in the car - because I don't want my dash cams, or radio for that matter, to stop me from starting the car. Ask me how I know. The power leads are long enough to make it out of the boot and I connect the inline volt meter to the battery, 12.6 Volt, the same as what I saw when I checked it a week earlier. I mount the VHF multi-band antenna, connect it to the radio after pulling out the N-Type to PL259 adaptor which is on the list and part of the standard kit. I take a breath and turn on my radio. Tune to the local repeater frequency and hit the PTT. The radio is set to 5 Watts and I'm hoping to hear the repeater tone. Nothing. I check all the repeaters in my radio, about seven of them, none of them do anything. Then .. I hear a click. I've been "on-air" for all of three minutes. I notice the radio is turned off. I've seen this before, sometimes stray RF gets into something and causes the radio to stop. I turn it back on and notice the voltage on the display of the radio, 9.65 Volts. That .. is .. not .. good. I check the inline volt meter, it doesn't even display anything. I turn off the radio to save what little power I have. I take a moment to consider and attach the HF antenna, hoping that I can run the radio for a few seconds to check the local 10m repeater. All is good to go, turn on the radio and it won't even turn on, just flickering on and off. I feel like I want to cry, but there doesn't seem to be any point. I pack everything back up, the water, my hat, the radio, the coax, the antennas, the table, the chair, put it all back in where it came from, even the sandwich I was going to have for lunch. After slowly reversing out of the car bay, looking carefully at the ground to make sure I didn't leave anything behind, I make my way out of the park. I've been there for a grand total of 29 minutes. I briefly entertain the idea of going to the nearest electronics store and spending $50 on a small battery, but I don't actually have a working charger, and spending several hundred dollars on a charger and battery is not really in my budget at the moment. Whilst I was driving home I got a notification that the power was out at my QTH. I got home 52 minutes after the power went out. It stayed off for the next six hours. So much for being productive. My friend Charles NK8O, tells me that his first few activations were a bust. He's a Sapphire POTA activator with 609 activations across 372 parks, so, there's hope for me yet. In looking back at this adventure, I was planning for failure. I'd thought through all the different permutations of what might happen. Not for one moment did I consider that my battery might be a single point of failure. That said, there were hints that not all was well. The 12.6 Volts was one hint, the fact that my dash cams have been acting up was another. I had been on the hunt for a battery monitor for the past two years to discover precisely what was going on, but I haven't found one that doesn't require a specific app that needs to know where you are or what's in your diary, so I put it out of my mind. As it happens, that was where I made my rookie mistake. Mind you, part of me knows that I don't have another battery anyway, so it really didn't matter if the battery was faulty or not. Either way, I wasn't going to connect my radio to my car battery, I learned that lesson well over a decade ago. I'm back to the drawing board. It's unlikely we'll use that location to activate for the 750th edition of F-troop, but when I get my power situation sorted out, it's still a lovely place to get on-air and make some noise. I'm Onno VK6FLAB

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

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

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