A reminder that the next foxhunt run by the Amateur Radio Experimenters Group will be run at 2pm today, starting with a foot based hunt around the Victoria Park Wetlands in the south park lands in the City, off Beaumont Road via South Terrace.
A vehicle based hunt will follow starting from ~3pm on both the 146 and 438 MHz amateur bands.
Fox hunts are now run monthly on the 1st Saturday of the month and are open to everyone to participate in. We hope to see you there!
Modern amateur radio is changing rapidly, and Software Defined Radio (SDR) is at the centre of that change. Many amateurs already own an SDR — or use one indirectly — but few have had the chance to understand how it actually works or why it feels so different from traditional radios.
This upcoming lecture will provide a plain‑language introduction to SDR, aimed specifically at amateur radio operators, not engineers or programmers.
Block diagram of a typical SDR Radio system (courtesy https://www.rfglobalnet.com)
Rather than focusing on mathematics or theory, the talk will explain SDR concepts using familiar radio ideas: receivers, mixers, filters, IF stages, and transmitters — and show how these functions are now being done in software instead of hardware.
Topics will include:
The lecture will also touch on GNU Radio, the most widely used SDR software framework, explaining what it does and why it has become so important — without requiring any programming knowledge.
Whether you are:
…this session is designed to demystify SDR and connect it back to the radio principles amateurs already know.
No prior SDR experience is required — just an interest in radio.
So when are where is this event? AREG meets at the Fulham Community Centre, off Phelps Court, in Fulham, Adelaide. Doors open at 7.00pm, Friday 17th April.
This month the meeting will begin with a short Special General Meeting to address a minor change to the group’s constitution, followed by the presentation which will likely start around 7.45pm.
For our regional members, the meeting will, as usual, also be interactively streamed via Zoom. If you are a regional amateur and are interested in finding out a little more about AREG, guest passes are available to our Zoom meetings on request. Please contact our secretary – via vk5arg@areg.org.au
During the 2010’s AREG used to regularly enter the John Moyle Field Day contest hosted by the WIA. For various reasons that activity waned in the last 4-5 years. So this year, we felt it was time to re-enter the event and introduce the next generation of AREG members to domestic field day contesting.
Given this is a “Field Day”, it really needed to be a in the field club activity. That is what puts the “field” into the event after all. This year we were fortunate, through a friend of one of our members, to gain access to a 10 acre plot on Hindmarsh Island, about 90 minutes out of Adelaide. The site, which had a 10-15m hill at the back of the property and a couple of sheds in the middle was perfect and allowed us to spread the antennas out so we could operate a multi-operator station without causing interference between the bands.
One of the unique tricks used in this contest was Andy VK5AKH’s quick deployment station. He hired a van for the weekend, rolled his portable operating desk inside, loaded it up with gear and away he went. He was on air within an hour of arriving on site supporting our full 40m station.
Powering The Station
We set up three 400W portable contest stations on the site and then proceeded to power them as follows:
We had 3x Honda EU20i generators on site, originally planning that as our base load generation, given this contest did not permit us to use the mains to run the station. However, we also had something new that we had never tried before.
One of our members owns a Geely EX5 electric car. This car was unique in that it came equipped with a 3kW 240 Volt AC inverter, which we could use to draw power from the car’s 61kWh battery! Before the event, we were pretty trepidatious – concerned that the car would generate a lot of RFI and interference across HF. To our very happy surprise, however, the car was as quiet as a church mouse. In the end, we ran 2 of the three stations on the car inverter for the whole event. In the process, we invented a new unit of electrical consumption – “equivalent kilometres”. The two stations connected to the car, each with their respective 400W linear amplifiers, used a total of 65km worth of electricity. Not bad given the car has 410km of road range. This really does open up a whole new world for field day contesting into the future!
As for operating the contest, we had a great turnout of operators, with VK5AKH, VK5QI, VK5FLY, VK5DUG, VK5VC, VK5FJ, VK5IR, VK5GR, VK5MN, VK5CIA. We also had a great roster of volunteers who helped construct and support the station including VK5ZM, VK5BX, VK5AG, VK5ZQV, VK5SAW, VK5KX, VK5AOK and others plus we had visits from Sue VK5AYL and David VK5ZL who were also interested to see what we were up to here at AREG.
We had operators as young as 10 yrs old (Douglas VK5DUG supported by dad Louis VK5FLY) right through to some in their mid 70s who remembered the John Moyle field day from a decade ago and wanted to come back and have another go. It was great to see them all getting into the spirit of the contest.
The crew was well looked after as well with support from Michael VK5MN who managed the catering and Jeremy VK5CIA who provided the bathroom facilities from his holiday home nearby. All the little things that become big issues when you are out in the field!
Results are not out yet, but we were pretty happy with our score. We had the station manned for 22 of the 24hrs of the contest, and due to the lack of contestants during the night spent at least 2 hours calling with no answers. None the less, a great time was had by everyone. We look forward now to seeing the results and discussing what we might try next year!
Horus flights 70A & 70B were ‘test & tune’ flights, giving receiving stations a chance to update their decoding software to receive our new ‘Horus Binary v3’ telemetry mode. These were run on the 15th and 29th of March, with just a single tracking payload flown on each launch.
This was the first of the test & tune flights, launched at 10:30AM on a nice calm and sunny day at Mt Barker.
Waiting for launch!
The payload on this flight was a single Vaisala RS41-SGE radiosonde, reprogrammed with the RS41ng open-source firmware. A Hwoyee 200g balloon was used, with a slow ascent rate targeting around 23-34km burst altitude – we ended up achieving a burst of 28.7km! The payload landed in a paddock approximately 15km to the north of Lameroo.
We had a great turnout of receivers on this flight, with 34 stations uploading telemetry for the new Horus Binary v3 mode. These were as follows:
AX5AA, BARC_4, Gum, VK3BQ, VK5AI, VK5AKK, VK5ALG, VK5APR, VK5ARG, VK5BL, VK5CV, VK5DSP, VK5GY, VK5HS/p, VK5HW, VK5KX, VK5LN, VK5NEX, VK5OCD, VK5OI, VK5PJ, VK5QI-9, VK5SFA/R, VK5ST, VK5ZAR, VK5ZM, VK5ZMD, VK5ZMK, VK5ZTS, VK5RK, VK5IS, webhorus-jms, webhorus-jyyrhv, webhorus-p9zuu5
Horus 70A Receiving Stations (Green dots)
The longest received distance was to Andrew VK3BQ with a range of 529km, and the last packet was received by Ivan VK5HS at 113km range, both excellent efforts!
A dashboard for the flight is available by clicking here.
Another calm launch day! This time around we used a smaller 100g balloon, targeting about 20km altitude. The payload was also a re-programmed Vaisala RS41 radiosonde, however this time it was modified to run off a single AA battery. This reduces the runtime to < 8 hours, but also reduces the payload mass to less than 40 grams!
Horus 70B just before release.
We ended up with a slow flight tracking north from the Mt Barker launch site, ascending to 23825m before bursting and landing north of Kersbrook.
Screengrab of the Sondehub-Amateur tracker during the flight, showing many receiving stations
We had a great round up of receiving stations, with 34 unique callsigns contributing to the tracking effort! It was also great to see a few new callsigns on the list compare to the previous flight. The full list of receiving stations is as follows:
BARC_RRR, Gum, MILEEND, VK5AKK-H, VK5AKK-V, VK5ALG, VK5ALG Mac ,VK5APR, VK5ARG, VK5BL, VK5CV, VK5DSP, VK5FLY, VK5GA, VK5HS/p, VK5HW, VK5KX, VK5LN, VK5NEX, VK5OCD, VK5OI, VK5QI-1, VK5QI-9, VK5ST, VK5ZAP, VK5ZBI, VK5ZM, VK5ZMD, VK5ZTS, VK5RK, vk5is, vk5st-991, vk5zts-1, webhorus-p9zuu5
The longest reception on this flight was by Michael VK5LN in Pt Lincoln, at a range of 285km – great work Michael!
A dashboard for this flight is available by clicking here.
Thanks to everyone that updated their tracking software and received these launches! We’re now much more confident in being able to move to Horus Binary v3 telemetry on our upcoming flights – having tracking redundancy through the many home stations receiving our flights really helps in ensuring they can be safely tracked and recovered.
Our next launch is planned to occur on Sunday the 26th of April, with a backup date on Sunday the 3rd of May. We are also expecting to perform a launch in mid to late May as part of the LaunchBox program. More details on these launches should be release in the next few weeks!
REMINDER:
Due to our hall being unavailable there won’t be a March general meeting of the Amateur Radio Experimenters Group
.
Rob AI6VN takes us behind the scenes of how the WSPRDaemon project works and how it is contributing to the HamSci community.
On the 20th of February 2026, AREG was introduced to the world of Amateur Radio microwave experimentation on the 241 GHz band by David VK5KK and Iain VK5ZD. Here is their story!
Firstly, AREG wishes to advise that we will not be holding our normal March Friday night meeting on the 20th of March, as our meeting venue is not available this month due to it being used as a polling booth for this year’s state election. Instead, AREG is pleased to announce that we have a special guest presenter, Rob Robinett AI6VN, who will join us online from California via Zoom at a special meeting time of Saturday March 7th at 10AM Australian Central Summer Time.
Rob Robinett, AI6VN, will present an in-depth overview of WSPRDaemon, a low-cost, wideband software-defined radio (SDR) system designed for continuous monitoring of the MF and HF spectrum. WSPRDaemon uses the 16 bit / 128 Msps RX-888 SDR receiver to digitize the entire 0-64 MHz spectrum which enables the simultaneous recording and reporting of 51 signals: all 11 of the WWV, WWVH and CHU time signals, all 18 of the 2200m – 6 meter WSPR bands, and all 22 of the FT4 and FT8 bands.
When the RX-888 is clocked by a GPS-Disciplined Oscillator, WSPRDaemon records WWV with sub-microhertz accuracy while WSPR ‘spots’ are reported with 0.01 Hz accuracy. That accuracy results in Doppler shift measurements like those shown in the above spectrogram, and from which radio scientists are gaining insights into previously poorly understood ionospheric dynamics, Traveling Ionospheric Disturbances (TIDs), and space-weather-driven propagation effects.
The system operates continuously 24/7 and automatically uploads WWV/CHU recordings to HamSCI servers where they are archived and made available for scientific research and collaborative analysis.
The presentation will cover system architecture, SDR hardware considerations, time and frequency accuracy requirements, software processing chains, and examples of real-world data products, including observations captured during geomagnetic storm events. Rob will also discuss how WSPRDaemon integrates into the HamSCI Personal Space Weather Station (PSWS) framework and how amateur radio operators can deploy stations that contribute meaningful, research-grade data.
This talk will be of particular interest to members involved in SDR, weak-signal modes, propagation research, frequency metrology, and advanced amateur experimentation.