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Starting in the wonderful hobby of Amateur or HAM Radio can be daunting and challenging but can be very rewarding. Every week I look at a different aspect of the hobby, how you might fit in and get the very best from the 1000 hobbies that Amateur Radio represents. Note that this podcast started in 2011 as "What use is an F-call?".
Updated: 3 hours 14 min ago

How are contests scored?

Sat, 07/24/2021 - 12:00
Foundations of Amateur Radio

The essential purpose of an amateur radio contest is to get on air and make noise. Each contest has a set of rules on how they intend to achieve this. An integral part of the rules is the idea that you establish a contact, a QSO, with another station and exchange some predefined information. Likely the callsign, a signal report and often something else, a serial number, the age of the operator, a maidenhead locator or the CQ or ITU zone. I'll race past the discussion around sending 5 and 9 as a standard signal report and move right along.

To validate your activity, you record this information in a log and after the contest has concluded, you share your log with the contest organiser who collates and processes the submitted logs to determine a winner. As a participant you look for your callsign on the results page and if you're lucky you get some form of trophy, a certificate, a plaque, or more often than not, a PDF. An amateur radio contest is not a particularly high stakes competition.

Recently I asked a group of contesters a question: "How do you learn why a QSO was excluded from your score?" I asked because one of the eight contacts I managed during a recent contest was disallowed, leaving me with an unexplained discrepancy between my log and the results. I will note that this entry didn't affect my ranking, I won my category, mainly because I was the only entrant - hah!

Depending on whom you ask, this is either a simple or a complex question.

The simple explanation states that if the contact isn't in the log of both stations it's not a valid contact. This interpretation was extremely popular in the group I asked.

It was not the only answer I received.

When I spoke with individual contesters they came up with different answers to my original question.

For example, if I log everything right, if I'm using a serial number, the number increments each time and my log shows that, then my log entry should be valid, even if the other station didn't log it correctly. Note that I said log, not copy, as-in, they repeated back what I gave them, but logged it incorrectly.

I also wondered what would happen if I was using a club-station callsign and accidentally called CQ with my own callsign and a station logged that callsign instead of the club-station. Should they be penalised because they logged what was actually exchanged?

There's more.

For example, what happens if the times are not identical? Based on the simple explanation, this would not be a valid contact, so you would not get recognition for this exchange and in some contests an invalid contact will produce a penalty to both stations.

Another variation to the simple answer occurs if the contest organiser doesn't receive a log for every station and as a result, some contests set a maximum number of contacts for stations without logs.

All this came within the context of attempting to discover how log validation happens, who decides what's valid and what rules are used. During my group conversation, two contest managers shared how they scored their particular contests and showed that they attempted to award the benefit of doubt to each station. One decided after the discussion to change their interpretation to the simple explanation I've already looked at.

I wanted to know if there was any standard and other than pointing vaguely in the direction of a few large contests, I didn't actually manage to find any definitive discussion on how this works, if it's universal, which I suspect it isn't, and if it changes over time, which I know it does.

The largest annual contest is the CQ World-Wide. In a 2012 blog post the contest committee discusses the time window of a contact and explains that they allow a 15 minute window, so as long as both contacts agree within 15 minutes, the QSO is allowed. That post also pointed out that if the time for one station was out by 45 minutes, none of their contacts would be allowed and anyone who made contact with that station would by implication get a penalty.

Clearly there are variations on how this is handled.

I asked if there is validation software for logs that checks this and if that software is open source so others can look at how decisions are made and see how these evolve over time. Is there an arbitration that goes beyond the standard phrasing in most contests: "The decision of the contest committee is final."

I was told that this wasn't necessary and I should focus on more practice. I beg to differ. I've been contesting for a decade now, I have plenty of winning certificates on my wall. I'd like to improve my skill and I'd like to learn why and how my contacts are disallowed and I'd like others to be able to do the same.

Log checking software is written by humans who interpret the rules and write software to conform to those rules. In order to see what rules are in place and to validate that, the source of that software must in my opinion be open and transparent.

As a community we sit at the boundary between professional communications and a hobby and we often use the idea and concepts of a contest to argue that this is the best way to hone skills and to make you a better operator in case of an emergency, but if you cannot actually learn from your mistakes, if there is no discussion on how decisions are made, if there's nothing beyond simple answers, then are we really striving for improvement or just set in our ways?

For the record, I think that if a contest log is off by 45 minutes throughout the entire log, software should pick that up, award the contacts and point out the mistake to the person who didn't set their clock correctly, especially since time is not exchanged during any contest I know. I also think that if a station logged what was actually said, there is room for that to be considered a valid exchange, but then I've only been an amateur contester for a decade, so I have plenty to learn.

I'm Onno VK6FLAB

Share if you care...

Sat, 07/17/2021 - 12:00
Foundations of Amateur Radio

When you explore the landscape of amateur radio you'll discover an endless array of innovation. There's websites with photos and descriptions of activities, places discovered and lessons learnt. If you watch the growing collection of YouTube channels you'll discover videos describing what people have been up to, commenting on videos they've seen and you'll start to notice that people all over the community are pinging off each other. Social media does the same.

If you read an amateur magazine, or a book, you'll unearth references and counter-references, links and credits, descriptions gleaned and tests made, all of them interlinking and adding to the knowledge base that underpins the amateur radio community and society beyond it.

The same is true for on-air activity. Look at contesting for example, you'll hear descriptions from other contesters, sharing their lessons learnt which potentially influence how you do your next contesting activity. The same is true for working DX, operating any digital mode, running an on-air net, running a SOTA activation, anything.

The point being that you are influenced by others and everything you do influences somebody somewhere else who in turn influences the next person who might then influence you. On and on the chain grows.

This chain of knowledge goes back to the early science in our hobby, the works of James Clerk Maxwell who for the first time brought electricity, magnetism, and light together as different manifestations of the same phenomenon in 1864.

The reason we know this is because he published his work and without needing to leave home to see the original, anyone can read it today from the comfort of their living room thanks to the PDF that's on the Royal Society web-site.

The point being that Maxwell documented his work and shared it with the world.

In our hobby we've gone through the process of making our equipment from unobtainium, requiring that the actual components were constructed before you could actually put them together and use them for their intended purpose. We then went on the scrounge for parts from other equipment, acquiring surplus gear and through a phase where you could buy new components off the shelf and attach them to an etched circuit board. That evolved into being able to design a board, ordering it online, having it built for cents and shipped to our door.

Today an increasing component of our hobby evolves around software with its unique property of transience.

Unlike physical components, software is intangible. You imagine how something might work, you describe it in an imaginary language, convert it into something that can be run inside a computer, and if you did it right, the outcome gives you the basis for your next experiment.

When software reaches a certain level of complexity it becomes impossible to remember. You tweak something over here and something over there changes and unless you can keep all that together inside your brain as a cohesive imaginary model, you quickly run into a brick wall.

If you're a software developer you've likely heard of tools like CVS, SVN and git. They are examples of revision control. They're used extensively in software development, but increasingly they're being used to track changes in documents, legislation and places where change is constant.

As an aside, if you load the various versions of legal requirements of your license into revision control, you'll quickly discover that your license is slowly evolving over time, for better or worse. From personal experience, I know doing that for the Radiocommunications Licence Conditions in Australia was very interesting indeed.

Each of these tools gives you the ability to tweak something, track it and if it doesn't work out, revert to where you started your experiment. It's a little like using a soldering iron and a soldering wick, physical undo for experiments.

When I talk about Open Source software, I'm not only talking about the ability to look inside and add functionality, I'm also talking about accessing the history that goes with that.

Open Source software generally only works if it comes with a revision history, a trail of discovery outlined right there on your screen showing what worked, why and how it came about. There's often options for showing who made what change, which changes happened at the same time and the ability to extract that particular change. All essential ingredients for experimentation.

Closed Source software does all those things, but privately. It too likely uses revision control tools, even the same ones as Open Source, but the discoveries are held in-house, behind closed doors, used by a select few. The software evolves inside the organisation, but there's no insight for or from the outside world.

Of course, everyone is entitled to keep their stuff secret, but if you want to make a contribution to society outside the life of your walled garden, the only way forward is to publish and share your work like scientists have been doing well before the Royal Society held its first meeting on the 28th of November 1660.

Share if you care...

I'm Onno VK6FLAB

What Open Source means to our hobby and why it's important.

Sat, 07/10/2021 - 12:00
Foundations of Amateur Radio

For much of the past month I've been attempting to articulate what Open Source Software is, why it's important, how it's relevant to our hobby, how it works, how software is different from hardware and why you should consider if the equipment you buy comes with source code or not. I'm finding it difficult to separate out the issues since they all hang together in a cohesive clump of ideas and concepts.

So, let me go sideways to set the scene.

There is a movement that asserts the right to repair our own things and to ensure that manuals and diagnostic tools used by manufacturers are made available to the public.

For many radio amateurs that might sound quaint and obvious, since for much of the hobby that kind of information was not only available, it was expected and assumed to be available. You can get the circuit diagram and testing procedures, the alignment process and the list of required test equipment for most if not all amateur transceivers today and truth be told, if that testing gear isn't available, we tend to build or scrounge our own.

Compare a Yaesu FT-857d and an Icom IC-7300. They're radios from different generations, use different technologies, are made by different manufacturers and come in different packaging.

Both radios have user manuals, circuit diagrams and documented testing and alignment processes, but they're not equivalent even if they look the same.

The 857 is constructed from discrete components and circuits. There's a microprocessor on-board, the source code is not available and updates are issued by the manufacturer if and when it sees fit. Its function is to control and sequence things, selecting band filters, switching modes, updating the display and control serial communications. While integral to the functioning of the radio, the microprocessor itself is used for command and control only.

Inside the 7300 you'll also find discrete components. There are circuits, filters and the like and while individual components have reduced in size there are many of the same kinds of functions inside the radio as you'll find on an 857. The microprocessor inside the 7300 is more advanced than the one inside the 857. The source code is also not available and updates are issued by the manufacturer when it sees fit.

If that was all there was to it, I would not have spent a month attempting to capture this. Suffice to say that looks are deceiving.

The microprocessor inside the 7300 does the exact same things as the 857 with one minor difference. It now also forms part of the signal input and output chain of the radio itself.

Let me say that again.

The computer that is the heart of a modern radio is an integral part of the signal processing of the radio. Where in a traditional radio the microprocessor was switching circuits on and off to process the signal, the modern solution is to do all the signal processing using software inside the microprocessor itself. If you want to get technical, an FPGA is doing much of the signal processing, but that too is driven by software.

Where previously you had access to the circuit diagram that would show you what was being done to the signal, today you have a magic black box that does stuff completely outside your control.

If you want to know how an SSB or FM signal is decoded on the 857, the service manual will helpfully point you at two chips which provide those specific functions. It describes how the signal comes into the chip and how the signal is processed once it leaves the chip and if you need more, you can look online to find the specifications for each chip to see precisely what they do and how they work, complete with equivalent circuits and specifications.

On the other hand if you wanted to know the same information for the 7300 you'd be out of luck because if you dig deep enough, following the signal path, eventually you'd end up inside the microprocessor where software is making that happen. There's no description on how this works, what the circuit equivalent characteristics are, there's no way to change how it works, no way to set parameters, no way to see inside and no way to experiment.

This is a problem because it means that you've got a solution that's no longer operating in the spirit of amateur radio. It's not open for experimentation, it's not subject to review, there's no way to test, no means to improve, no way to do anything other than what the manufacturer decided was appropriate.

For example, if I wanted to modify the FM pass-band width on an 857, I could update the FM demodulation circuit by replacing a couple of components. On a 7300, I could not because there is no circuit. The FM demodulator is described in software that I don't have access to and Icom has decided that the FM pass-band is fixed.

If the software was open however, I could add this function and make it available to anyone who would like to experiment.

At this point I'd also like to observe that the Icom user manual states that inside the IC-7300 it uses open source "CMSIS-RTOS RTX", "zlib" and "libpng" software, so Icom is benefiting from open source efforts, but not sharing their own.

This is not an Icom only problem, this is a specific issue around open source versus closed source and while you might think that the right to repair and open source is something that's not relevant to you, I'd like to invite you to consider what the implications are for our hobby. Are we going to go down the road of button pushers, or are we continuing our role as inventors and experimenters?

I'm Onno VK6FLAB

What mode is that?

Sat, 07/03/2021 - 12:00
Foundations of Amateur Radio

The hobby of amateur radio is about communication. When you go on-air and make noise, you initiate a communications channel, sending information out into the world and hoping for another station to receive and decode what you sent. The channel itself can be used in an infinite number of ways and each one is called a modulation mode, or mode for short. The popular ones come with most radios, CW, AM, SSB and FM.

Those few are not the only ones available. In fact as computers are being integrated into the radio at an increasing pace, signal processing is becoming part and parcel of the definition of a mode and new modes are being introduced at break neck speed. I've talked about WSPR as an example of one such mode, but there are many, each with their own particular take on how to get information between two stations.

As you listen on the bands you'll increasingly find yourself hearing a bewildering litany of beeps, pops and clicks. Some of those are due to ionospheric conditions, but many are different modes that are being experimented with across our spectrum.

If you have access to a band scope, a way of visualising radio spectrum, you can actually see the shapes and patterns of such signals over time and getting to that point can be as easy as feeding your radio audio into your computer and launching a copy of fldigi or WSJT-X.

Every mode requires a specific tool to decode it and with practice you'll discover that there is often a particular look or sound associated with a mode. Over time you'll confidently select the correct decoder, using your brain for the process of signal identification.

Of course if you don't have access to the library in your brain yet, since you've only just started, or if the mode you've come across is new, you'll need another library to discover what you found. There is such a library, the Signal Identification Wiki. It's a web-site that hosts a list of submitted signals, grouped by usage type, including one for our community.

On the amateur radio page of the Signal Identification Wiki there are over 70 different modes listed, complete with a description, an audio file and a spectrogram. With that you can begin to match what you've discovered on your radio to what the web-site has in the library and determine if you can decode the incoming information.

I will mention at this point that the Signal Identification Wiki is far from complete. For example, the Olivia mode has 40 so-called sub-modes of which about 8 are in common use. Each of those sub-modes looks and sounds different. The wiki shows only a single line for Olivia.

I'm pointing this out because the wiki allows you to submit a mode for others to use. If you have a signal, either by recording it off-air, or better still, recording it directly from the source, consider submitting it to the wiki so others can benefit from your experience.

If you've come across a signal and you cannot figure out what it is, there are other places you can go for help. The four and a half thousand members of the /r/signalidentification sub on reddit will happily look at and listen to your signal and try to help. Make sure you contribute some meta data like the time, frequency and location to accompany the spectrogram and audio.

You might have come to this point wondering why I'm encouraging you to use and contribute to the wiki and ask for help on reddit. Amateur radio is about experimentation. We love to do that and as we make signal processing easier and easier, more people are making new modes to play with.

The speed at which this is happening is increasing and as an operator you can expect to come across new signals. I remember not that long ago, it was last month, tuning to an FT8 frequency and the person I was with asking what that sound was. They'd heard it before but never discovered its purpose, even though FT8 has been with us since the 29th of June 2017.

What interesting signals have you come across and how did you go with decoding them?

I'm Onno VK6FLAB

When you share the hobby grows ...

Sat, 06/26/2021 - 12:00
Foundations of Amateur Radio

Recently I received a lovely email from Simon G0EIY, who reminded me that there is a voice-keyer that fits into a microphone. It was designed by Olli DH8BQA as a replacement for a standard Yaesu MH-31 microphone. I'd come across this a while ago and for several reasons put off actually ordering one, but Simon's encouragement tipped me over the fence and I've placed my order.

What I'm expecting to arrive at some point is a kit that has the minuscule surface mount components already soldered to a circuit board, leaving a couple of individual components ready for my soldering iron abuse. I'll let you know how it goes.

This little experience reminded me that I've been stumbling across solutions like this for years, an amateur with an itch to scratch and the drive to do something about it.

For example, Paul KE0PBR likes to operate satellites and in doing so amassed a collection of frequencies. Since the Doppler effect alters the actual frequency depending on the satellite coming towards you or moving away from you, there are corrections that need to be done. If you're in the field, this is something that you might struggle with, so Paul created a Frequency Cheat Sheet.

If you're looking into magnetic loop antennas, you'll quickly encounter a spreadsheet made by Steve AA5TB that will get you started with the parameters for designing and building your own magnetic loop.

The popular VK Contest Logger, known colloquially as VKCL was built by Mike VK3AVV. It's a simple to use logging tool that has a large collection of rules for different contests and Mike often brings out a new version to incorporate the latest rule changes just before a contest. It even incorporates a station log.

If you've come across apps like DroidPSK, DroidSSTV and DroidRTTY, they're the brain children of Wolfgang W8DA. The increasingly popular Repeaterbook maintained by a global community of volunteers is the work of Garrett KD6KPC.

I've lost count of the number of radio amateurs running an online shop where you can buy gear, or kits, or circuit boards, components, antennas, software and the like, not to mention an astonishing collection of professionally built tools like antenna analysers, filters, amplifiers and more.

It's said that amateurs are notorious for their short arms and deep pockets. I like to think of it as a discerning and informed customer. It's easy to sell snake-oil to the masses, it's been going on for centuries, it's much harder to do that when the person you're selling to knows how the thing you're selling works and knows how to read a data-sheet, let alone ask awkward questions when the need arises.

Before I go on I will mention that the people I've named here are unaware of me doing so. I've not been approached by any of them to mention their name and I have no relationship, other than being a happy customer. I'm saying this out loud because this podcast goes out on amateur radio repeaters all over the world and commercial use of amateur radio is strictly prohibited.

You might have gotten to this point wondering why I'm even taking the time to highlight some of the efforts I've come across and the reason is very simple. This activity is everywhere, you just have to look. It's not like Olli, Paul, Steve, Mike, Garrett or Wolfgang shouted their involvement from the rooftops, it's just that the information is available if you care to look. Remember, these people are radio amateurs just like you and I.

That's important because the difference between a tool that you're using that you built, sitting in your shack or on your computer and that of the people I've named is that they took an extra step and shared their efforts with the community. Some amateurs are making a living from this hobby and I applaud their efforts, for the rest of us, me included, that's often not the point.

Invention is happening all over the world, right now. You are doing it, despite your protestations to the contrary. You might have made a PDF that you carry around during a contest, or it might be a calculator you knocked up to figure out how to build something. It might be a circuit diagram, an app, a how to guide, a map or a video. All of these things are creations that can be shared to increase the amount of innovation that happens by people bouncing ideas off other ideas.

In 1675, Sir Isaac Newton said: "If I have seen further it is by standing on the shoulders of Giants."

You are one of those giants and the person who uses your contribution to make their own is standing on your shoulders.

What are you waiting for?

Publish, share, document, photograph and make available, it's how society makes progress and it's how amateur radio stays at the forefront of innovation.

Get on air and make noise is not purely restricted to the RF spectrum.

I'm Onno VK6FLAB

Here be Dragons, venturing into uncharted territory ...

Sat, 06/19/2021 - 12:00
Foundations of Amateur Radio

Sometimes when you head into uncharted territory, you gotta laugh at yourself from time to time. Last weekend I participated in a contest, something I enjoy doing as you might recall. To simplify the process of setting up in a vehicle I'd proposed a bold plan to save space and reduce complexity. I was anxious about reducing the amount of technology because I'd come up with a plan to use a paper log to track my contest contacts.

I had visions of operating for the best part of 24 hours and making hundreds of contacts. This was based on the fact that in 2016 I'd done this same contest on my own and made a 138 contacts and scored 18221 points, having moved 17 times.

I'd also done the contest in 2018 and for reasons I don't recall, I made one contact over 8 hours.

That right there should have been a warning sign that I might not quite get the result I'd been fearful of.

Blissfully unaware of the adventure that was unfolding, after driving to the first location, I called CQ for the better part of an hour. Then I called some more. When I was done with that, I called CQ more. 90 minutes in, I made my first contact.

That pretty much set the pattern for the next nine hours. At one point we feared that the radio had packed up, but then I made a 2900 km contact with the other side of the country between me in Perth in VK6 and Catherine VK7GH in Tasmania.

Around five pm we packed up, having moved location six times, making eight contacts and claiming 64 points, having worked three of the six states I heard.

Talk about overblown fears.

Looking back, even documenting 138 contacts on paper doesn't seem nearly as daunting after the fact, but that's for another day. I did learn some other things too.

I was worried about logging the band correctly, since using a computer that's not connected to the radio requires an extra step when you change band. Using paper the issue wasn't the band, it was remembering to record the time.

We didn't have the opportunity to test all the gear before the contest. I was bringing in some extra audio splitters, which didn't work with the set-up we had, testing before hand would have revealed that. We knew that there was a risk associated with not testing before and decided that in the scheme of things it didn't matter and we were right. It didn't.

We hadn't much planned for food and pit-stops, but having a GPS and an internet connection solved all those issues almost invisibly. Of course that wouldn't work in an unpopulated area, but we were well inside the metropolitan area of a big city, well, Perth.

Using a head-set worked great, though it didn't have a monitoring feature, so my voice got louder and louder and Thomas VK6VCR who took on the tasks of navigating and driving became deafer and deafer as the day progressed.

I keep coming back to wanting a portable voice-keyer, a device that you can record your CQ call into and then at the press of a button, play it back so you don't lose your voice whilst calling CQ hour after hour. The challenge seems to be that you need to find a way to incorporate it into the existing audio chain so it doesn't introduce interference.

Winning a contest requires contacts and that can only happen if there are other participants. This time around there didn't seem to be that many on air making noise. I think I heard a grand total of 13 stations. Some of that was due to propagation conditions which were nothing like I've ever heard before, but perhaps if I stick around for another solar cycle, that too will become familiar. Atrocious is one word that comes to mind.

Continuing our learning, the weather, not just space-weather, actual earth weather, snow, rain, hail and in our case sun. Neither of us thought to bring a hat since the forecast was for intermittent rain. We had no rain, instead had the opportunity to bask in the winter sun. Yes, it's winter here in Oz when it's Summer in Europe. As it happens, our winter temperatures are like your summer ones, but I'll leave it to you to confirm that for yourself.

Finally, we have a local phenomenon in VK6. When the sun goes down, the 40m band comes alive with the sounds of Indonesia. Among the radio amateurs are plenty of pirate stations with massive AM transmitters enjoying the conditions, chatting, chanting and what ever else comes to voice. Not conductive to being on-air and making noise, but as far as I can tell, not commonly heard outside of VK6.

That said, the Indonesian radio amateur community must have the patience of saints putting up with the interference that their non-licensed countrymen cause on a daily basis. My hat off to you!

As I've said all along, this radio thing is about getting on air and having fun and I can tell you, we did.

What did you get up to?

I'm Onno VK6FLAB

Removing technology for a change

Sat, 06/12/2021 - 12:00
Foundations of Amateur Radio

My first ever interaction with amateur radio was a field day on Boterhuiseiland near Leiden in the Netherlands when I was about twelve. The station was set-up in an army tent and the setting was Jamboree On The Air, or JOTA. My second field-day, a decade ago, was a visit to a local club set-up in the bush. At that point I already had my licence and I'd just started taking the first baby steps in what so-far has been a decade long journey of discovery into this amazing hobby.

A field day is really an excuse to build a portable station away from the shack and call CQ. A decade on, I vividly remember one member, Marty, now VK6RC, calling CQ DX and getting responses back from all over the world.

From that day on I looked for any opportunity to get on air and make noise. Often that's something I do in the form of a contest. I love this as a way of making contacts because each interaction is short and sweet, there's lots of stations playing from all over the planet and each contest has rules and scores. As a result you can compare your activity with others and look back at your previous efforts to see if you improved or not.

As you've heard me repeatedly say, I like to learn from each activity and see if there are things I could have done differently. I tend to think of this as a cycle of continuous improvement.

A few months ago a friend asked me if I was interested in doing a contest with him. For me that was a simple question to answer, YES, of course!

Over the last few months we've been talking about how we'd like to do this and what we'd like to accomplish. For example, for me there's been a regular dissatisfaction that during portable logging I've made mistakes with recording the band correctly in the log and having to manually go back and fix this, taking away from making contacts and having fun. To prevent that, I wanted to make sure that we had electronic logging that was linked to the radio in the same way as I do in my shack, so it didn't happen again. It was a small improvement, but I felt it was important.

Doing this meant that we'd either need to sort out a computer link, known as CAT, or Computer Assisted Tuning for his radio in the vehicle, or bring my radio, CAT control, power adaptors as well as bring a laptop, power supply and last but not least find space in the vehicle to mount all this so it would work ergonomically for a 24 hour mobile contest. The vehicle in question is the pride and joy of Thomas VK6VCR, a twenty-odd year old Toyota Land Cruiser Ute with two seats, three if you count the middle of the bench, and neither of us would ever be described as petite, so space is strictly limited.

In playing this out and trying to determine what needed to go where, we discovered that this wasn't going to work and I made the bold proposal to go old school and use a paper log.

This would mean that we could use the existing radio, without needing to sort out CAT control, the need for any power adaptors, no space required for a laptop, no power for that, no extra wiring in the vehicle, and a whole lot more simplicity. So that's what we're doing, paper log and a headlamp to be able to see in the dark.

I must confess that I'm apprehensive of this whole caper, but I keep reminding myself that this too is an experience, good or bad, and at the end of the day, we're here to have fun. I might learn that this was the worst idea I've ever had, or I might learn that this works great. It's not the first time I've used a paper-log, so I'm aware of plenty of pitfalls, not the least of which is deciphering my own handwriting, the ingenuous project of three, or was it four, different handwriting systems taught to me by subsequent teachers in different countries. There's the logistics of being able to read and write at an odd distance, trying to work out how to operate the microphone with the wrong hand, though we are trialling a headset and boom microphone with a push to talk button, and then there's the radio, one I've used before, but not in a contest setting and not whilst driving around on the seat of a 4WD hell-bent on rattling my teeth from their sockets.

On the plus side, I've done a contest with my friend before and he is familiar with my competitive streak and we're both up for a laugh, so I'm confident that despite the challenges that lie ahead, we're going to make fun and enjoy the adventure.

I can't wait to find out if simplifying things will result in a better experience and only trying it will tell. I'll let you know how it goes.

When was the last time you stepped out of your comfort zone and what did you do? How did it work out?

I'm Onno VK6FLAB

What radio should I buy as my first one?

Sat, 06/05/2021 - 12:00
Foundations of Amateur Radio

Recently a budding new amateur asked the question: "What radio should I buy?"

It's a common question, one I asked a decade ago. Over the years I've made several attempts at answering this innocent introduction into our community and as I've said before, the answer is simple but unhelpful.

"It depends."

Rather than explaining the various things it depends on, I'm going to attempt a different approach and in no particular order ask you some things to consider and answer for yourself in your journey towards an answer that is tailored specifically to your situation.

"What's your budget?"

How much money you have set aside for this experiment is a great start. In addition to training and license costs, you'll need to consider things like shipping, import duties and insurance, power leads and a power supply, coax leads and connectors and last but not least, adaptors, antennas and accessories.

"Should you buy second hand or pre-loved?"

If you have electronics experience that you can use to fix a problem with your new to you toy this is absolutely an option. When you're looking around, check the provenance associated with the equipment and avoid something randomly offered online with sketchy photos and limited information. Equipment is expensive. Check for stolen gear and unscrupulous sellers.

"What do you want to do?"

This hobby is vast. You can experiment with activities, locations, modes and propagation to name a few. If you're looking at a specific project, consider the needs for the accompanying equipment like a computer if what you want to explore requires that. You can look for the annual Amateur Radio Survey by Dustin N8RMA to read what others are doing.

"What frequencies do you want to play on?"

If you have lots of outdoor space you'll have many options to build antennas from anything that radiates, but if you're subject to restrictions because of where you live, you'll need to take those into account. You can also operate portable, in a car or on a hill, so you have plenty of options to get away from needing a station at home.

"Are there other amateurs around you?"

If you're within line of sight of other amateurs or a local repeater, then you should consider if you can start there. If that doesn't work, consider using HF or explore space communications. There are online tools to discover repeaters and local amateurs.

"Is there a club you can connect to?"

Amateur radio clubs are scattered far and wide across the planet and it's likely that there's one not too far from you. That said, there are plenty of clubs that interact with their members remotely. Some even offer remote access to the club radio shack using the internet.

"Have you looked for communities to connect with?"

There is plenty of amateur activity across the spectrum of social media, dedicated sites, discussion groups, email lists and chat groups. You can listen to podcasts, watch videos, read eBooks and if all that fails, your local library will have books about the fundamental aspects of our hobby.

"Have you considered what you can do before spending money?"

Figuring out the answers to many of these questions requires that you are somewhat familiar with your own needs. You need a radio to become an amateur, but you need to be an amateur to choose a radio. To get started, you don't need a radio. If you already have a license you can use tools like Echolink with a computer or a mobile phone. If you don't yet have a license, you can listen to online services like WebSDR, KiwiSDR and plenty of others. You can start receiving using a cheap RTL-SDR dongle and some wire.

"Which brand should you get?"

Rob NC0B has been testing radios for longer than I've been an amateur. His Sherwood testing table contains test results for 151 devices. The top three, Icom, Kenwood and Yaesu count for more than half of those results. This means that you'll likely find more information, more support and more local familiarity with those three. I will point out that Rob's list has 27 different brands on it, so look around and read reviews both by people who test the gear and those who use it.

And finally, "Why are you here?"

It's a serious question. Different things draw different people into this community. Think about what you like about it and what you want to do more of. Take those things into consideration when you select your radio.

As you explore the answers to these questions, you'll start building a picture of what amateur radio means to you and with that will come the answer to the question: "What radio should I buy as my first one?"

If there are other questions you'd like to ask, don't hesitate to get in touch. My address is [email protected] I look forward to hearing from you.

I'm Onno VK6FLAB

Bringing chaos into order

Sat, 05/29/2021 - 12:00
Foundations of Amateur Radio

One of the questions you're faced with when you start your amateur journey is around connectors. You quickly discover that every piece of equipment with an RF socket has a different one fit for purpose for that particular device.

That purpose includes the frequency range of the device, but also things like water ingress, number of mating cycles, power levels, size, cost and more.

As an aside, the number of mating cycles, how often you connect and disconnect something is determined by several factors, including the type of connection, manufacturing precision and the thickness of the plating. That said, even a so-called low cycle count connector, like say an SMA connector lasting 500 cycles will work just fine for the next 40 years if you only connect it once a month.

Back to variety. My PlutoSDR has SMA connectors on it as do my band pass filters, my handheld and one RTL-SDR dongle. The other dongle uses MCX. Both my antenna analyser and UHF antenna have an N-type connector which is the case for my Yaesu radio that also has an extra SO239 which is what my coax switches have. My HF antenna comes into the shack as an F-type and nothing I currently own has BNC, but stuff I've previously played with, does.

When you go out on a field-day, you mix and match your gear with that of your friends, introducing more connectors and combinations.

Invariably you acquire a collection of adaptors. At first this might be only a couple, quickly growing to a handful, but after a while you're likely to have dozens or more. My collection, a decade's worth, which currently includes more than 25 different combinations is over a hundred individual adaptors and growing.

For most of the time these have been tossed into a little tool box with a transparent lid, but more and more as the collection and variety grew I started to realise that I was unable to quickly locate an adaptor that I was sure I had, since it had been used in a different situation previously.

In addition to coming to the realisation that the reason I couldn't find a connector was because it was still in use, I began to notice that I had daisy chains of connectors.

For example, my HF antenna has a PL259 connector that is adapted to an F-type connector with an SO239 barrel, a PL259 to BNC and a BNC to F-type adaptor. At the other end of the RG6 coax that runs from outside into the shack, the reverse happens, F-type to BNC and BNC to PL259. If you're counting along, that's five adaptors to get from PL259 to PL259 via F-type.

At this point you might wonder why I'm using RG6 coax. The short answer is that I have several rolls of it, left over from my days as an installer for broadband satellite internet. RG6 is very low loss, robust and heavily shielded. Although it's 75 Ohm - a whole other discussion - in practice that's not an issue. What is a problem is that the only connectors available for it are F-type compression connectors. To get those to PL259 requires a step sideways via BNC.

My point is that the number of adaptors is increasing by the day.

I should acknowledge the existence of so-called universal connector kits. The idea being that you go from one connector to a universal joiner and from that to another connector. Generally these kits have around 30 connections, giving you plenty of options, but in reality more often than not, you only have half a dozen universal joiners, so your money is effectively buying you half a dozen conversions, great for a field day, not so great for a permanent installation. You could build your own collection and use something like SMA or BNC as your universal joiner, which is something I'm exploring.

To keep track of my collection, recently I started a spreadsheet. It's essentially a list showing the number and types of connections. If you make a pivot table from that you'll end up with a grid showing totals of adaptors you have.

You can use this grid to fill a set of fishing tackle boxes and all of a sudden you've got a system where everything has its own place.

If you start this process you'll quickly notice that the table only needs to be half filled, since a BNC to SMA is the same as an SMA to BNC adaptor. This leaves you space to do some fancy footwork where the bottom right hand of the triangle can fit into the top left of the empty space, but I'll leave you to figure that out.

My table also includes things like TNC and MCX adaptors, but I don't use those very often, so at the moment I'm putting them in their own box together with T-adaptors and other weird and wonderful things like FME and reverse SMA.

For setting the order, I've gone for alphabetic, but if you have a better suggestion, I'm all ears. My email address as always is [email protected]

What ideas have you come up with to organise the chaos that is your sprawling connector library?

I'm Onno VK6FLAB

Streaming a dozen repeaters with an RTL-SDR dongle

Sat, 05/22/2021 - 12:00
Foundations of Amateur Radio

A while ago as part of my ongoing exploration into all things radio I came across a utility called rtlsdr-airband. It's a tool that uses a cheap software defined radio dongle to listen to a station frequency or channel and send it to a variety of different outputs. Originally written by Tony Wong in 2014, it's since been updated and is now maintained by Tomasz Lemiech. There are contributions by a dozen other developers.

The original examples are based around listening to Air Traffic Control channels. I know of a local amateur who uses it to listen to and share the local emergency services communication channels, especially important during local bush fires.

While sophisticated, it's a pretty simple tool to use, runs on a Raspberry Pi, or in my case, inside a Docker container. It's well documented, has instructions on how to compile it and how to configure it.

Before I get into what I've done, as a test, let's have a look at the kinds of things that rtlsdr-airband can do.

First of all, it's intended to be used for AM, but if you read the fine documentation, you'll learn that you can also make it support Narrowband FM. It can generate output in a variety of different ways, from a normal audio file, to an I/Q file - more about that at another time, and it can also send audio as a stream to a service like icecast, broadcastify or even to your local pulse audio server. If that last one doesn't mean much to you, it's a local network audio service, popular under Linux, but it runs on pretty much anything else thanks to the community efforts of many.

So, on the face of it, you can listen to a channel, be it AM or Narrowband FM, and send that to some output, but I wouldn't spend anywhere as much time on this if that was all there was to it.

The software can also dynamically change channels, support multiple dongles, or simultaneously listen to several channels at once and output each of those where ever you desire.

Another interesting thing and ultimately the reason I thought to discuss it here is that rtlsdr-airband also supports the concept of a mixer. You can send multiple channels to a single mixer and output the result somewhere else.

Using a mixer, in addition to setting cut off frequencies and other audio attributes, you can set the audio balance for each individual channel. This means that you can mix a channel exclusively to the left ear, or to the right ear, to both, or somewhere in between.

Now, to add one extra little bit of information.

In my location there's about a dozen or so amateur repeaters most of which can be heard at some time or another from my QTH. The frequency spread of those dozen repeaters is less than 2 MHz. A cheap RTL-SDR dongle can handle about 2.56 MHz.

Perhaps you've not yet had the ah-ha moment, but what if you were to define an rtlsdr-airband receiver that listened to a dozen amateur radio repeaters - at the same time - and using the audio balance spread those repeaters between your left and right ear, you could stream that somewhere and listen to it.

I'm sitting here with my headphones on, listening to the various repeaters do their idents, various discussions on different repeaters, a local beacon, incoming AllStar and other links, all spread out across my audio horizon, almost as if you can see where they are on the escarpment, though truth be told, I've just spaced them out evenly, but you get the idea.

My original Raspberry Pi wasn't quite powerful enough to do this in the brute force way I've configured this, so as a proof of concept I'm running it on my main computer, but there's nothing to suggest that doing a little diligent tweaking won't make my Pi more than enough to make this happen.

As for audio bandwidth, it's a single audio stream, so a dial-up connection to the internet should be sufficient to get the audio out to the world.

I will point out that there may be legal implications with streaming your local amateur repeaters to the world, so don't do that without checking.

For my efforts, this is an example of: "I wonder if ..."

As it turns out, Yes you can. As it happens, my next challenge is to use this code on a PlutoSDR where the bandwidth is slightly larger, mind you, I'll have to do some fancy footwork to process the data without overwhelming the CPU, but that's another experiment in my future.

What kind of crazy stuff have you tried that worked?

I'm Onno VK6FLAB

Soldering Irons and Software

Sat, 05/15/2021 - 12:00
Foundations of Amateur Radio

The activity of amateur radio revolves around experimentation. For over a century the amateur community has designed, sourced, scrounged and built experiments. Big or small, working or not, each of these is an expression of creativity, problem solving and experimentation.

For most of the century that activity was accompanied by the heady smell of solder smoke. It still makes an appearance in many shacks and field stations today, even my own, coaxed by an unsteady hand, more and more light and bigger and bigger magnification, I manage to join bits of wire, attach components and attempt to keep my fingers from getting burnt and solder from landing on the floor.

I've been soldering since I was nine or so. I think it started with a Morse key, a battery and a bicycle light with a wire running between my bedroom and the bedroom of my next door neighbour. In the decades since I've slightly improved my skill, but I have to confess, soldering isn't really my thing.

My thing is computers. It was computers from the day I was introduced in 1983 and nothing much has changed. For reasons I don't yet grasp, I just get what computers are about. They're user friendly, just picky whom they make friends with.

When I joined the amateur community, it was to discover a hobby that was vast beyond my wildest imagination, technical beyond my understanding and it was not computing. Little did I know.

Computing in amateur radio isn't a new thing. For example, packet radio was being experimented with in 1978 by members of the Montreal Amateur Radio Club, after having been granted permission by the Canadian government. In 2010 when I came along we had logging, DX-clusters and the first weak signal modes were already almost a decade old.

Software Defined Radio has an even longer history. The first "digital receiver" came along in 1970 and the first software transceiver was implemented in 1988. The term "software defined radio" itself was 15 years old when I joined the hobby and truth be told, it's a fascinating tale, I'll take a look at that at another time.

When I started my amateur journey like every new licensee, I jumped in the deep end and kept swimming. From buying a radio, to discovering and building antennas, from going mobile to doing contests and putting together my home station, all of it done, one step at a time, one progressive experiment after another, significant to me, but hardly world shattering in the scheme of things.

Now that I've been here for a decade I've come to see that my current experiments, mostly software based, are in exactly the same spirit as the circuit builders and scroungers, except that I'm doing this by flipping bits, changing configurations, writing software and solving problems that bear no relation to selecting the correct combination of capacitance and reactance to insert into a circuit just so.

Instead I'm wrestling with compilers, designing virtual machines, sending packets, debugging serial ports and finding new and innovative ways to excite transceivers.

For example, today I spent most of the day attempting to discover why when I generate a WSPR signal in one program, it cannot be decoded by another. If that sounds familiar, that was what I was doing last week too. This time I went back to basics and found tools inside the source code of WSJT-X and started experimenting. I'm still digging.

As an aside I was asked recently why I want to do this with audio files and the short answer is: Little Steps.

I can play an audio file through my Yaesu FT-857d. I can receive that and decode it. That's where I want to start with my PlutoSDR experiments, so when I'm doing this, I can use the same audio file and know that the information can be decoded and that any failure to do so is related to how I'm transmitting it.

Back to soldering irons and software. In my experience as an amateur it's becoming increasingly clear that they're both the same thing, tools for experimentation, with or without burning your fingers.

I'm Onno VK6FLAB

Getting started on WSPR with a PlutoSDR

Sat, 05/08/2021 - 12:00
Foundations of Amateur Radio

As you might recall, I took delivery of a device called a PlutoSDR some time ago. If you're not familiar, it's a single-board computer that has the ability to transmit and receive between 70 MHz and 6 GHz. The system is intended as a learning platform, it's open source, you get access to the firmware, compilers and a whole load of other interesting tools. I used it to play with aviation receive using a tool called dump1090 which I updated to use Open Street Map. If you're interested, it's on my VK6FLAB github page.

Over the past few months I've been steadily acquiring little bits and pieces which today added up to a new project.

Can I use my PlutoSDR to transmit WSPR?

This all started because of an experiment and a conversation.

The experiment was: "Using my FT-857d on 70cm can I transmit a weak signal mode like WSPR and have my friend on the other side of the city decode the transmission?" The answer to that was a qualified "Yes". I say qualified, since we weren't able to transmit a WSPR message, but using FT8 we were happily getting decodes across the city. We're not yet sure what the cause of this difference is, other than the possibility that the combined frequency instability at both ends was large enough to cause an issue for a WSPR message, which lasts about two minutes. On the other hand, I learned that my radio can in fact go down to 2 Watts on 70cm. I've owned that radio for over a decade, never knew.

Now that I have a band pass filter, some SMA leads and the ability to talk to my Pluto across the Wi-Fi network, I can resurrect my Pluto adventures and start experimenting.

I mentioned that this was the result of an experiment and a conversation.

The conversation was about how to create a WSPR signal in the first place. At the moment if you run WSJT-X the software will generate audio that gets transmitted via a radio. All fine, except if you don't have a screen or a mouse. Interestingly a WSPR transmission doesn't contain any time information. It is an encoded signal, containing your callsign, a maidenhead locator - that's a four or six character code representing a grid square on Earth, and a power level. That message doesn't change every time your transmitter starts the cycle, so if you were to create say an audio file with that information in it, you could just play the audio to the nearest transmitter, like a handheld radio, or in my case a Pluto, and as long as you started it at the right time, the decoding station wouldn't know the difference.

As an aside, if you're playing along with your own Pluto, and far be it for me to tell you to go and get one, you can set the Pluto up using either USB, in which case it's tethered to your computer, or you can get yourself a USB to Ethernet adaptor and connect to it via your network. If you have a spare Wi-Fi client lying around, you can get that to connect to your Wi-Fi network, connect the Pluto via Ethernet to the Wi-Fi client and your gadget is connected wirelessly to your network. I can tell you that this works, I'm typing commands on the Pluto as we speak.

As is the case in any experiment in amateur radio, you start with one thing and work your way through. At the moment I want to make this as simple as possible. By that I mean, as few moving parts as I can get away with. I could right now fire up some or other SDR tool like say GNU Radio and get it to do the work and make the transmission, but what I'd really like to do is actually have the Pluto do all the work, so I'm starting small.

Step One is to create an audio file that I can transmit using the Pluto.

It turns out that Step One isn't quite as simple as I'd hoped. I located a tool that actually purports to generate an audio file, but the file that it builds cannot be decoded, so there's still some work to be done.

On the face of it the level of progress is low, but then this whole thing has been going for months. The experiment on 70cm lasted half an hour, the discussion took all of a cup of coffee. So far, I've spent more time on this project making the Wi-Fi client talk to my network than all the rest put together and that includes finding and ordering the Pluto in the first place.

You might well wonder why I'm even bothering to talk about this as yet unfinished project. The reason is simple. Every day is a new one. Experiments are what make this hobby what it is and every little thing you learn adds to the next thing you do. Some days you make lots of progress, other days you learn another way to not make a light bulb.

I'm Onno VK6FLAB

Ergonomics in your shack

Sat, 05/01/2021 - 12:00
Foundations of Amateur Radio

In my day job I work in computing. For many years that consisted of going on-site and fixing stuff. Invariably this involved me fixing servers that were installed into a room the size of a broom closet with an optional air conditioner screaming in my ear. The experience often included sitting on a crate, or the floor, holding a keyboard and if it was a Windows Server, rolling a mouse on my knee in order to click on stuff barely discernible on a tiny screen that likely sat a meter too high above my eye line with Ethernet wires going diagonally from one end of the room to the other.

These days with ubiquitous internet connectivity that kind of experience is mostly a thing of the past.

That said, operating a radio during a contest in many stations I've used over the years is not far from that kind of layout.

Often a traditional shack starts off with a radio on a table with a notepad to record contacts. Over time that gets expanded with technology like a computer. It's common to have to juggle the radio display and keyboard, to find a spot for the mouse that doesn't interfere with the desk microphone, or to have to reach over to change band and to activate a different filter, select another antenna, use the rotator or some other essential tool that's required for making that elusive contact.

Some stations have multiple monitors, sometimes they're even together, but more often than not they're a different size, sitting too high and the radio sits as a road-block between your eye line between the screen and the keyboard.

I'm raising this because over the years I've not actually seen anyone spend any energy on discussing how you might improve this experience.

If this was your workplace, the occupational health and safety police would be all over you and for good reason. You could argue that amateur radio is a hobby and that OH&S is of lesser concern, but to that I'd like to point out that you have the same risk of self injury at work as you do in your shack, especially if you're doing a contest for 24 or 48 hours.

Not only is there a risk of injury, why make the experience harder than it needs to be? Ergonomics is the process of designing or arranging a workplace to fit the user. It's a deliberate process. You have to actually stop to consider how you are using a space, in this case your shack.

At the moment I'm experimenting with different aspects of the layout of my shack. For example, I started with a layout of the computer, counter intuitive perhaps, since we're talking about a radio shack, but given that I'm spending much of my time doing contests and digital modes, the computer is used much more than the radio is, even if the radio is what's making all the on-air noise.

After making sure that my keyboard, mouse and screen were in locations that actually helped me, I started trying to figure out where to put the radio and what role it actually plays in making the contact. If during a contest you're using search and pounce, which is when you hunt up and down the bands looking for a contact, you might argue that you'll need access to the radio to change frequency, but if you already have your computer connected to the radio, you can change frequency from the keyboard or by control with your mouse.

Another way I'm looking on reducing the amount of stress to my body whilst operating my station is by sorting out audio. Almost every radio has a speaker on it, but if you've got more than one going at the same time it becomes really difficult to determine which one is actually making noise and even harder if multiple stations are on different frequencies on different radios at the same time.

You could wear headphones and select a radio, one at a time, either by plugging in a particular radio, or by using a selector. If you're using digital modes, the audio might already be going into the computer, which offers you the ability to select from different sound cards, but there are other options. I'm working on plugging the audio from each radio into an audio mixer that will allow me to set the level for each radio independently, mute at will, set the tone, the balance between left and right ear and a few other things.

For a microphone I plan on using the same mixer and I'm working on how to have my digital audio coming from the computer incorporated into the same audio environment, because the digital audio could just as easily be a voice caller using the same system.

For push to talk I settled on a foot switch a couple of years ago. That said, if I'm on my own, I tend to use VOX, or voice operated switching, which turns on the transmitter when microphone audio is detected by the radio. This will need some careful planning if I'm going to connect multiple radios, since I don't want to transmit the same message across each radio at the same time, but with computer control, that too can be addressed.

My point is that we have lots of technology available to us as radio amateurs to achieve what ever we need to. It takes extra effort to decide how you might go about making your environment a place where you can safely sit and operate without making life harder than it needs to be.

What kinds of different techniques and technologies have you used to make your shack a more comfortable environment? Do you spend your days hunting DX, doing contests or making digital contacts, or something else? Have you considered how you might improve the layout of your shack to suit your particular use-case and when was the last time you checked to see if the decisions you originally made are still valid today?

I'm Onno VK6FLAB

How much bandwidth is there?

Sat, 04/24/2021 - 12:00
Foundations of Amateur Radio

Have you ever taken a moment to consider the available bandwidth on the various amateur bands?

As an entrant into amateur radio in Australia as a Foundation licence holder you have access to six different amateur bands, the 80m band, 40m, 15m, 10m, 2m and 70cm. If you add the bandwidth from each of those bands together, you end up with 26.65 MHz worth of bandwidth to play with in Australia.

I can tell you that's a big chunk of bandwidth, but until I give you some context, 26.65 MHz isn't likely something that you can picture.

You might think of things as being pretty crowded. For example, on the 40m band during a contest it's common to hear wall to wall signals. There's barely enough room to call CQ and not interfere with anyone else. But how crowded is it really?

Let's start with an SSB signal, typically it's 2.4 kHz wide. On the 40m band, with 300 kHz of bandwidth, there's room for about 125 SSB signals side-by-side. On the 10m band, there's space for over 700 SSB signals side-by-side. Across all the available bandwidth for a Foundation license holder in Australia, there's room for over 11-thousand different SSB signals side-by-side.

While we're on the subject of crowding, there's talk about the massive influx of FT8, some call it a scourge. FT8 channels are transmitted within a single SSB channel and each takes up 50 Hz. That means that within an SSB channel of 2.4 kHz, there's room for 48 different FT8 channels, and if you take into account the odd and even time-slots, that doubles to 96 different signals, all within the same single SSB channel. So while FT8 is popular and growing, let's not get too excited about how much space it's taking up. From the perspective of an Australian Foundation license holder, it's taking up exactly six separate SSB slots of those 11-thousand across the six available bands, room for 576 separate FT8 signals, taking up a total of 14.4 kHz, or 0.05% of the available bandwidth.

Let's look at this another way, of the 26.65 MHz available bandwidth, 20 MHz is from the 70cm band alone, that means that all the other bands put together, fit inside the 70cm band three times over.

Let that sink in for a moment, adding the 80m, 40m, 15m, 10m and 2m band together fit inside the 70cm band three times.

You can use the 70cm band alone for 800-thousand FT8 signals, remember that there's two time slots, so you get two for one.

If this makes your mind explode, then consider that a carrier wave signal is considered to be about 25 Hz wide, so on the 70cm band you could have 800-thousand individual CW signals. You could allocate a personal CW frequency to every one of the amateurs in the United States in the 70cm band and still have room for expansion, not that I'm advocating that, just to give you a sense of scale. I should note that the 70cm band in the United States is even larger than it is in Australia, but I don't want to get bogged down into the various band plans across the world at the moment.

You might ask yourself why am I getting so excited about this?

Amateur radio is about experimentation. I've been telling you about HF propagation and using techniques like FT8 to determine just how far your signal goes, but you could use the same techniques to build a 70cm communication network with the amateurs within your city and share information across the city, perhaps even build a mesh network using your 70cm hand-held and an FT8-call network. It could be used to distribute propagation information, or messages in case of an emergency, or form the basis of something completely different.

If that doesn't whet your appetite, consider that the 1mm amateur band, which runs from 241 to 250 GHz is ready for you to experiment when your license permits. The current world distance record is 114 km, set in 2008 by Brian WA1ZMS and Peter W4WWQ, it has 9 GHz bandwidth and has room for 360-million FT8 signals, or 60 exclusive FT8 channels for every amateur on the planet.

My point is that as radio amateurs we have access to a massive chunk of radio bandwidth and it's just sitting there waiting for you to experiment with.

I'm Onno VK6FLAB

The massive physics phenomenon just over eight minutes away ...

Sat, 04/17/2021 - 12:00
Foundations of Amateur Radio

If you've been around radio amateurs for a little while you're likely to have heard about the Solar Cycle and that it affects radio propagation for HF or High Frequency, also known as shortwave communications. The frequencies in the range of around 3 to 30 MHz, or 100m to 10m wavelength. One of the main ways it's used is for is for long distance or global communication and one of the most common ways that's done is using the ionosphere around the globe to refract a radio signal.

In September 2020, the Solar Cycle 25 Prediction Panel, announced that Solar Cycle 25 had commenced in December 2019 and radio amateurs around the globe rejoiced.

The first question for me was, why Solar Cycle 25?

You might think of the Sun as a stable light in the sky. As it happens, the bright light hides all manner of ferocious activity. One of the measures of this activity is the number of dots observed on the surface of our Star. These dots are called sunspots. As Solar activity increases, the number of sunspots increases. The activity is cyclical, it increases and decreases over time. Each increase and decrease combined is known as a Solar Cycle.

On average a cycle lasts about 10.7 years. Simple maths gives you that Solar Cycles started somewhere around 1750. That seems a little strange. Our Sun is 4.6 billion years old. There are paintings on the rocks at Ubirr in the Northern Territory of Australia that are 40 thousand years old. The pyramids in Egypt are 45 hundred years old. The Solar Cycle has been going for a lot longer than the 7 million years there have been humans on the planet, let alone dinosaurs who experienced the Solar Cycle 66 million years ago. Using fossil records we've determined that the Solar Cycle has been stable for at least the last 700 million years.

Chinese astronomers recorded Solar activity around 800 BC and Chinese and Korean astronomers frequently observed sunspots but no known drawings exist of these observations. The first person to draw sunspots was John of Worcester on the 8th of December 1128. Five days later, half a world away in Korea on the 13th of December 1128, the astronomers in Songdo reported a red vapour that "soared and filled the sky", describing the aurora borealis in the night sky that resulted from those very same sunspots.

In the early 1600's there was plenty of activity around the recording of sunspots. Thomas Harriot appears to have predated Galileo Galilei by more than a year with notes and drawings dated the 8th of December 1610. There's plenty of other names during this period, Father and son David and Johannes Fabricius and Christoph Scheiner to name three, but I'm moving on.

The Solar Cycle, was first described by Christian Horrebow who more than a century later in 1775 wrote: "it appears that after the course of a certain number of years, the appearance of the Sun repeats itself with respect to the number and size of the spots". Recognition of the Solar Cycle was awarded to Samuel Heinrich Schwabe who noticed the regular variation in the number of sunspots and published his findings in a short article entitled "Solar Observations during 1843" in which he suggested that the cycle was 10 years.

Stay with me, we're getting close to Solar Cycle number One.

In 1848 Rudolf Wolf devised a way to quantify sunspot activity. His method, named the Wolf number, is still in use today, though we call it the relative or international sunspot number. In 1852 he published his findings on all the available data on sunspot activity going back to 1610 and calculated the average Solar Cycle duration as 11.11 years. He didn't have enough observations to reliably identify Solar Cycles before 1755, so the 1755-1766 Solar Cycle is what we now consider Solar Cycle number One lasting 11.3 years with a maximum of 144.1 sunspots in June of 1761.

Until 2009 it was thought that there had been 28 Solar Cycles between 1699 and 2008 with an average duration of 11.04 years, but it appears that the 15 year Solar Cycle between 1784 and 1799 was actually two cycles, making the average length only 10.7 years. I should also point out that there have been Solar Cycles as short as 8 years and as long as 14 years.

With the announcement of Solar Cycle 25 comes improved propagation for anyone who cares to get on air and make noise. The current predictions vary depending on the method used, ranging from a very weak to a moderate Solar Cycle 25. There are predictions for the Solar maximum, the time with the most sunspot activity, to occur between 2023 and 2026 with a sunspot range between 95 and 130. By comparison during the previous Solar Cycle, in 2011 the first peak hit 99 and the second peak in 2014 hit 101.

I have purposely stayed away from electromagnetic fields, geomagnetic impacts and the actual methods for HF propagation, I'll look at those another time.

I can tell you that we've gone a little beyond counting dots on the Sun to determine activity and we have a whole slew of satellites orbiting our Star doing all manner of scientific discovery, all of which helps our understanding of what's going on in the massive physics phenomenon 8 minutes and 20 seconds away by radio.

That said, Solar eruptions are still pretty unpredictable, much like the weather around us. Not because we don't want to know, but because this is a very complex one to solve, much like ionospheric propagation is hard to forecast, much easier to measure actual performance and much more accurate.

So, if you want to know how well propagation is going to be today, turn on your radio and have a listen. If you want to know how great it's going to be tomorrow, look at the forecast, but bring an umbrella, or an FT8 transmitter.

I'm Onno VK6FLAB.

The dynamic nature of your shack

Sat, 04/10/2021 - 12:00
Foundations of Amateur Radio

If you have the opportunity to build your shack, it might start off as a table in the corner where you plonk down a radio, plug into nearby power and run coax to. That's pretty much how most shacks start, mine included.

For me the step of running coax was an activity that took weeks of planning and procrastination and days of climbing on the roof. After actually completing that and getting two runs of coax to my planned shack, one for HF and one for UHF and VHF, the shack building itself was pretty simple.

I had to get power to the location, but an extension lead took care of that. In the interest of space I put the power supply on the floor, a wooden floor that ensured good circulation, unlike carpet, perhaps a topic for another day, I plugged my coax into the radio, plugged in the 12 Volt power and was up and running.

Over time that space continued to grow. Looking at it right now, it has two computer monitors, a laptop, three radios, two coax switches, a keyboard, mouse, digital interface, two speakers, and a fan to cool the radio when I'm calling CQ on FT8.

I'm not a messy person, but I do like to have my tools convenient. It's not a pristine environment by any stretch, but it's orderly as shacks go. An hour ago it wasn't, actually, looking at the clock, that was four hours ago. Time flies when you're having fun.

My shack is the centre of my radio activities. I might receive a gadget from a friend to test and I'll put it on my desk ready to go. The same is true for a foot pedal that I found when looking for something else, as is the audio adaptor that I used in the desk mixer that I'm experimenting with.

Over time each of these bits and pieces accumulate on the surface.

When I noticed that my radio was running hot, or in my mind uncomfortably warm, given that I'm using 5 Watts, I decided to invest in a fan, clipped to the edge of the desk requiring yet another wire.

It's not limited to small bits. I'm testing a new radio, that comes with removable head, a microphone, cables to join those to the main body, two antenna port cables, a coax switch and a power lead with two cables.

Over time you have coax mixed with 12 Volt DC and 240 Volt AC, audio leads, USB leads, video leads, grounding wire, remote control switches, microphone leads, CAT leads and more, all running all over the place.

Making a minor change can become a big hassle, making it hard to determine what goes where, not to mention that each cable generates it's own little slice of RF, wanted or not.

The four hours I've just spent consisted of taking everything except the bolted on computer monitors off the desk and starting from scratch.

I also did this when I first added a second radio, but that was so long ago that the "system" I implemented then was unrecognisable. Doing it again today I made better use of the environment and changed some things around. I started with the 240 Volts requirements, then the coax, then 12 Volts, then audio and finally USB, using cable ties for semi-permanent things like power boards and hook and loop straps for things that move more frequently like audio wiring and video cables.

It's not perfect. I'm looking for some flexible coax patch leads, there's USB cables going every which way, the laptop keyboard isn't used, so why use a laptop, no doubt I'll discover more.

My point is that this is dynamic and every now and then it pays to spend a little while putting things back together.

My next project is to use an audio mixer to bring all the audio together in one place so I can use one headset for everything and give me the opportunity to plug in a tape recorder as my regulator suggests for monitoring emergency communications, though I might have to come up with something a little less 1980 for the actual recording.

If you're going to do this, move the desk at least a meter from the wall so you can get at the back of your shack, you can thank me later.

I'm Onno VK6FLAB