Foundations of Amateur Radio

Foundations of Amateur Radio A few weeks ago I discovered that the regulations for amateur radio in Australia had some definitions that caused me to wonder if 2,312 amateurs in VK, me among them, had been operating illegally? Specifically it appeared that using a WSPR or Weak Signal Propagation Reporter transmitter of any kind, both computer controlled and stand-alone beacons, was contrary to what...

Foundations of Amateur Radio I recently discussed some of the notions of amateur radio as emergency response. The idea that you might jump into the breach and be a hero is appealing and often celebrated. The American Radio Relay League, or ARRL, proudly tells the story of two amateur radio emergency communication events. One, of a person who fell in their bathroom and happened to have a handheld r...

Foundations of Amateur Radio Amateur radio is an activity that falls between two camps, those who think of it as a service and those who approach it as a hobby. I think that the notion of amateur radio as a service is often repeated, but in my time as part of this community, I've seen little evidence of actual service. That said, the idea of amateur radio as a service is often linked to emergency...

Foundations of Amateur Radio The other day I came across an amateur who expressed concern that someone was using a frequency set aside for repeater use with their hotspot. Band plan issues aside, and you are encouraged to send an email to cq@vk6flab.com with the link to the official band plan that applies to your DX entity, in my experience it's not unusual for an amateur who is configuring their...

Foundations of Amateur Radio From the 19th of February 2024, the ACMA, the Australian Communications and Media Authority, the regulator, is modifying the rules for amateur radio in Australia by moving to an amateur class license where all amateurs will operate under the same license instead of under an individual one. You must be qualified to operate under the new class license and all currently l...

Foundations of Amateur Radio The other day I stumbled on a project called Maia SDR by Daniel EA4GPZ. Maia, spelled Mike Alpha India Alpha, is a star in the Pleiades cluster. The Maia SDR project homepage proclaims that it is "An open-source FPGA-based SDR project focusing on the ADALM Pluto". Now, I can completely understand if that collection of words is gibberish to you, but take it from me, it'...

Foundations of Amateur Radio The attraction to amateur radio for me lies in the idea that it provides a framework for experimentation and learning. There's never an end to either. Each time you go on-air is an opportunity to do both and every chance I get, I cannot help being sucked into another adventure. My weekly scribbles are an attempt to both document what I've been up to and to encourage ot...

Foundations of Amateur Radio Today I'm going to spend a little longer with you than usual, but then, I think this is important and it's good to end the year on a bang. Have you ever attempted to make contact with a specific DXCC entity and spent some time exploring the band plan to discover what the best frequency might be to achieve that? If you got right into it, you might have gone so far as to...

Foundations of Amateur Radio Walking into your shack is often a joyous experience. You take a moment to smile at your setup and, at least mentally, rub your hands in glee anticipating some fun. Well, that is how it is for me, but recently it's been less of that and more of an audible groan at the accumulated cruft that makes it nigh on impossible to sit down, let alone achieve anything fun. It's n...

Foundations of Amateur Radio Cars have been here for well over a century and so has radio. Cars pretty much start when Carl Benz first applied for a patent for his "vehicle powered by a gas engine" on the 29th of January 1886 which is regarded as the birth certificate for automobiles. Radio starts as a thing when Heinrich Hertz proves that radio waves exist in 1888. Since then things have changed,...

Foundations of Amateur Radio There is a perception in the community that the hobby of amateur radio is an expensive way to have fun. While it's entirely possible to spend thousands of dollars on equipment, in much the same way that it's possible if your preferred hobby is golf, getting started does not have to require that you start planting money trees. Lots of fun can be had using cheap amateur...

Foundations of Amateur Radio Amateur radio is an activity enjoyed by many people around the world. How many exactly is cause for debate. The most recent official figure we have is from the IARU, the International Amateur Radio Union. In 2020 it counted over 3 million people, but an article written a year later puts that figure at 1.75 million. In Australia there's a common narrative that the total...

Foundations of Amateur Radio For years I've been hosting a weekly net called F-troop. It's a one hour opportunity for new and returning amateurs to get together and share their questions, and sometimes answers, about anything and everything amateur radio, with side trips into astronomy, electronics, circuit boards, testing gear and whatever else takes our fancy on the day. The net runs for an hour...

Foundations of Amateur Radio During the week I started a new project. If you know me at all, this is not unusual. Having worked in the IT industry for nearly 40 years it's also not unusual that projects have a way of surprising you and this project was no different. Recently I've been talking about antennas, a topic close to the heart of many amateurs and one that garners a lot of opinion and in m...

Foundations of Amateur Radio Let's compare the same antenna in different locations... Over the years I've spent many hours building and testing antennas. I've talked about this and discussed how there is essentially an infinite variety of antennas that can exist. To give you a sense of this, picture a basic dipole antenna, two bits of wire, same length, connected to a feed-point. We're doing this...

Foundations of Amateur Radio All antennas have a radiation pattern that charts on a sphere where it radiates more and where it radiates less than the theoretical isotropic radiator. This comparison is expressed as dBi antenna gain. There is a fundamental concept in antenna design called "reciprocity". Essentially it means that transmit and receive behaviour of an antenna is identical. In other wor...

Foundations of Amateur Radio After recently talking about noise, today I want to discuss gain, specifically antenna gain. When you say that your antenna has 18 dBi gain, what does that mean? This entire discussion starts with an isotropic radiator or antenna. It's often described as the perfect antenna, but rarely is there any description on how that actually works, so I'd like to start there. Bef...

Foundations of Amateur Radio Today I'd like to talk about noise, but before I do, I need to cover some ground. Recently I explored the idea that, on their own, neither antenna, nor coax, made a big difference in the potential for a contact when compared to the impact of path loss between two stations. I went on to point out that you'd be unlikely to even notice the difference in normal communicati...

Foundations of Amateur Radio Recently I explained some of the reasons why I've shifted to using dBm to discuss power. You might recall that 1 Watt is defined as 1,000 mW and that's represented by 30 dBm. 10 Watts is 40 dBm, 400 Watts, the maximum power output in Australia is 56 dBm and 1,500 Watts, the maximum in the USA, is just under 62 dBm. My favourite power level, 5 Watts, is 37 dBm. I mentio...

Foundations of Amateur Radio The other day I went looking for a software defined radio or SDR for HF. This happened because all such devices on my desk are rated at higher frequencies and I've still not managed to fix the broken SMA board connector on the transverter I purchased over a year and a half ago. In case you're wondering, the design has two SMA connectors attached at either end of a prin...

Foundations of Amateur Radio If you've been following my amateur radio journey, you'll have likely noticed that I've been straying from the fold. The words I use for power have been changing. I've reduced references to Watt and increased use of the term decibel. Initially this was incidental, recently it's been more of a deliberate decision and I'd like to explain how this came to be. It starts wi...

Foundations of Amateur Radio Between decibels and milliwatts ... As you might recall, I've been working towards using a cheap $20 RTL-SDR dongle to measure the second and third harmonic of a handheld radio in an attempt to discover how realistic that is as a solution when compared to using professional equipment like a Hewlett Packard 8920A RF Communications Test Set. I spent quite some time discu...

Foundations of Amateur Radio Over the weekend a friend of mine convinced me to help plant some trees. Mind you, I was told that this was going to be a blue tree painting day. The Blue Tree Project is now a global awareness campaign that paints dead trees blue to spread the message that "it's OK to not be OK", and help break down the stigma that's still largely attached to mental health. In the pro...

Foundations of Amateur Radio Before we start I should give you fair warning. There are many moving parts in what I'm about to discuss and there's lots of numbers coming. Don't stress too much about the exact numbers. In essence, what I'm attempting is to explore how we can reduce the power output from a transmitter in such a way that it doesn't blow up a receiver whilst making sure that the signal...

Foundations of Amateur Radio Recently I had the opportunity to use a piece of professional equipment to measure the so-called unwanted or spurious emissions that a transceiver might produce. In describing this I finished off with the idea that you could use a $20 RTL-SDR dongle to do these measurements in your own shack. I did point out that you should use enough attenuation to prevent the white s...