AREG August 19th AGM Meeting: 3Y0J Bouvet Island Expedition

The next meeting of the Amateur Radio Experimenter’s Group will be the our Annual General Meeting, to be held on Friday August 19th. Proceedings will start at 8:00pm ACST (8:30pm AEST, 6:30pm AWST, 1030UTC).

Our guest speaker for the evening is Adrian KO8SCA, one of the team members of the 3Y0J Bouvet Island DXpedition, who will join us via Zoom from his home in New York. Adrian will take us through the challenges facing the 3Y0J team and preparatory work that has been completed so far for this epic adventure.

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AREG July Meeting – Lightning Talks: AREG members in the VHF/UHF Field Day

Hopefully you have noticed by now that AREG is currently heavily promoting VHF and UHF activity within the Amateur Service. Many of our members took the hint and got up on the air for the WIA’s Winter VHF/UHF field day this year!

Now that the event is over, we thought it would be great to review the events of the day and have each of those who participated give a short 5 minute summary of their experiences on VHF/UHF in the contest this year. So the next meeting will be a series of member “Lightning Talks” – 5 minutes each on how you went, what you did, what worked and what didn’t – so that we can share the experiences and learning ready for the next event in Spring.

To hear how everyone went, come along to the AREG meeting this Friday night, starting at 7.30pm. AREG meets at the Fulham Community Centre, off Phelps Court, Fulham. Visitors are most welcome.

For those members interstate or locally who cant attend in person, the meeting will as usual also be conducted in parallel online via Zoom. Visitors who would like to attend our meeting via Zoom can email our secretary – Mark via to request guest access to the Zoom conference for the night.

After the presentations, there will be a short business meeting. This is our last business meeting for 2021/22 as the AREG Annual General Meeting will take place next month, on the 19th of August.

We also hope to have a special guest speaker at the AGM – stay tuned for more details!

Next Fox Hunt: Friday June 24

This Friday night, being the second Friday of the month, would have usually seen our monthly fox hunt being held, however many AREG members and friends are off to the South Australian Riverland this weekend to provide communications assistance in the annual River Paddling Marathon, therefore our June fox hunt has been pushed back to Friday the 24th of June.

As usual, the hunt commences at 6:30pm from the car park at the Adelaide Aquatic Centre, with hunters meeting around 15 minutes prior.

All of our fox hunts are open to all to join us, you do not need to be a member of AREG to join in on the fun.

We look forward to seeing you on the night.

Horus 57 Flight Report – 40km Altitude Achieved!

Horus 57 was the first ‘large’ Project Horus high-altitude balloon launch in over a year, and was aimed at getting more stations involved in receiving the common telemetry and imagery systems used on our launches, and at the same time try and get some nice imagery of our state from the air!

The launch was originally scheduled for the 1st of May, but weather conditions resulted in the imagery launch being bumped a week, and a small telemetry launch taking its place. The telemetry-only flight was very well received, with 37 unique stations contributing telemetry, building anticipation for the full-scale launch, which was performed on Saturday the 7th of May at 10AM.

The Payloads: Wenet Imagery

Horus 57 Wenet PayloadThe main payload on this launch was a Wenet imagery payload. Wenet is an imagery downlink system first developed by David VK5DGR and Mark VK5QI in 2016, to enable high resolution imagery to be downlinked from a balloon launch. It uses Frequency Shift Keying (FSK) at 115kbit/s to send specially encoded JPEG images which can be reassembled from packets received by many spatially diverse receivers.  It’s also completely open source, so anyone can have a go at using it!

This particular Wenet payload was testing a camera lens made by ArduCam, in the hope of obtaining higher quality imagery. Unfortunately this lens de-focused as the temperature of the payload dropped during flight, resulting in many blurred images. We’ll be switching back to the tried-and-tested Raspberry PiCam v2 for future flights of this payload.

The Payloads: Tracking & Flight Management

Reprogrammed RS41

The flight also included the usual complement of telemetry and flight management payloads. Primary telemetry was provided by a reprogrammed RS41, transmitting the ‘Horus Binary‘ 4FSK mode on 434.200 MHz. This was received by a large number of amateur stations running the ‘Horus-GUI’ demodulation software. Tracking of the payload was available on the SondeHub-Amateur tracker online, allowing global access to the position of the balloon throughout the flight.

The separate flight management payload was a LoRa-based payload operating in the 70cm amateur band. This payload allows remote termination of the flight if necessary (and it was very nearly used on this flight!).

The Payloads: LoRaWAN Beacon

Horus 55 LoRaWAN PayloadAlso on this flight was an experimental LoRaWAN tracking payload built by Liam VK5LJG. The aim was to transmit position beacons into ‘The Things Network‘ (‘TTN’), which has gateways (receiver stations) in many locations across Australia. This payload previously flew on Horus 55.

The payload operated on the 915-928 MHz LIPD band, with a transmit power of ~50mW. The hardware was a RAK Wireless RAK5205 board, running custom firmware for the flight. Position updates were only sent every ~3 minutes to comply with TTN fair-usage guidelines.

Unfortunately this payload stopped being received approximately 30 minutes into the flight, due to a misconfiguration. We’ll try this again on another flight!


The launch crews arrived on-site at the Mt Barker High School oval around 9AM on the Saturday morning, and started preparations for launch. The entire preparation process through to launch was documented by AREG club member Iain VK5ZD:

This flight used a Hwoyee 1600g balloon, one of the largest balloon sizes we regularly use. Since the combined payload mass was relatively light (~600g), a relatively small amount of gas was required, resulting in the balloon being quite under-inflated, and prone to wind drag.

Immediately after launch, it was noted that the ascent rate was lower than the expected 5 m/s, a direct result of the increased drag on the under-inflated balloon.

Thanks to all that helped out at the launch site! It was great to see some new faces, and the many hands made the launch much easier.

Starting the Chase

Original Horus 57 Flight-Path Prediction

Original Horus 57 Flight-Path Prediction

The original flight path prediction had the flight landing somewhere off the Stott highway, between Swan Reach and Loxton. However, the slower than expected ascent rate after launch meant the live flight-path predictions began to move further to the east.

The chase teams for the day consisted of Mark VK5QI and Will VK5AHV, and Gerard VK5ZQV.

The chase teams immediately headed off towards Swan Reach, and met up with some members of the Riverland Radio Club who had setup a receiving station for the imagery payload near the locality of Maggea. Peter VK5PE, Colin VK5CBM, Andy VK5LA, and Ivan VK5HS with his grandson Reece had decided to head out to setup near the predicted landing area and have a go at receiving imagery. This was their first time receiving the Wenet imagery payload, and so had brought along a lot of equipment to experiment with!

Riverland Radio Club Portable HAB Receiving Station

Riverland Radio Club Portable Receiving Station

There was also many other stations that had gone portable to receive the Wenet imagery. Peter VK5KX was setup near Sanderston with a WiMo X-Quad antenna and tracking rotator system, and Andrew VK5LA setup north of Swan Reach with a 15-element yagi. Andrew VK5CLD was also setup near Mt Barker summit with a homebrew 8-element yagi.

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Burst & Recovery

As the flight progressed, the reported altitude reached the expected 38000 m, and kept on rising! Unfortunately for the chase teams, at this altitude the balloon and payloads were heading east at 150 kph, and the predicted landing location with it, and so they had to get back on the road and continue onwards.

There was a tense period as the predicted landing location moved right across the Murray River, before finally moving further onwards to the east of Loxton. Around this time the flight continued on upwards, passing through 39000 m altitude, then finally 40000 m.

The ascent rate slowed down considerably above 40 km altitude, and there was a short time when the use of the cutdown payload was seriously considered to avoid the payloads ending up across the Victorian border. This ended up not being necessary though, as the balloon burst for a maximum reported altitude (based on the Wenet telemetry) of 40246 m! This is most likely the highest altitude ever reached by an amateur balloon launch in Australia!

Wenet Imagery from 40205m altitude!

The payloads then began to plummet back to earth (a peak descent rate of 114 m/s was observed just after burst!) and ended up landing in a newly seeded paddock approximately 15 km to the north-east of Loxton.

Horus 57 Flight Path

Horus 57 Flight Path

After obtaining permission from the landowner, the chase teams were able to carefully drive into the paddocks and recover the payloads.

The Wenet imagery payload was still operating, and captured the recovery and walk back to the car:

Wenet Imagery!

All the way through the flight, the Wenet payload continued to transmit live imagery to many receiving stations around the state. Unfortunately the new ArduCam lens shifted in focus due to the extreme cold temperatures experienced during the flight, resulting in most of the imagery above 3 km altitude being blurred. The lens appeared to recover around the peak of the flight, but then degraded again on descent before recovering after landing:

Wenet Reception Statistics

This flight saw the highest number of Wenet receiver stations ever, with 14 separate receiving stations contributing imagery packets. As a result, we had 100% image reception over the vast majority of the flight! This is a great result, and allows those watching from home to experience our high-altitude balloon launches in near real-time.

The following amount of data was contributed by each station:

  • VK5LA: 205297 packets (50.12 MB)
  • VK5KX: 179744 packets (43.88 MB)
  • VK5QI-1 (Home): 160507 packets (39.19 MB)
  • VK5CBM: 145899 packets (35.62 MB)
  • VK5PW: 134465 packets (32.83 MB)
  • VK3TNU: 134264 packets (32.78 MB)
  • VK5APR: 157585 packets (38.47 MB)
  • VK5EME: 146062 packets (35.66 MB)
  • VK5QI (Mobile): 131933 packets (32.21 MB)
  • VK5HS: 104472 packets (25.51 MB)
  • VK5CLD: 47650 packets (11.63 MB)
  • VK5IS: 21995 packets (5.37 MB)
  • VK5TRM: 16950 packets (4.14 MB)
  • VK5FJGM: 5355 packets (1.31 MB)

Horus 57 Wenet Receiver Map

While most of the receiver stations were relatively close to the flight path, we also saw Ian VK5IS receiving from 160km away, and Tim VK3TNU receiving from over 300km distance! Tim was using a 9-element RFI yagi, paired with a RTLSDR and preamplifier, and has set the new record for Wenet reception distance!

The following plots show the percentage of each image that was received by each receiver station:

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Horus Binary (4FSK) Telemetry Reception Statistics

We also saw a huge number of Horus Binary receiving stations come online for this flight, with stations as far away as Melbourne contributing telemetry. A total of 41 unique callsigns were observed to upload telemetry throughout the flight, which is also a new record for a Project Horus launch!

A huge thanks to everyone that contributed to the flight tracking, and we hope to see you on the map on future launches!

Detailed statistics for each receiver are available in the table below:

[table id=41 /]

The SondeHub-Amateur Tracker

Horus 56 and 57 made use of the new SondeHub-Amateur tracker website to enable anyone online to follow the flight’s progress. This is an extension to the SondeHub Radiosonde tracker, which allows tracking of meteorological radiosondes, and is developed by club members Michaela VK3FUR and Mark VK5QI, along with many other contributors.

The SondeHub-Amateur tracker in action during Horus 57.

The SondeHub project is supported by a grant from Amateur Radio Digital Communications, via the Amateur Radio Experimenters Group.

Flight Summary

[table id=42 /]

Future Launches

The next large Horus launch will likely be a re-flight of the DVB-S payload flown on Horus 55, with an improved payload antenna. This will likely need to wait until after winter, for clearer skies.

In the meantime, there are some initial plans for:

  • A re-flight of the LoRaWAN payload, though not to as high an altitude as on this flight.
  • Experiments with new sensors attached to our primary tracking payload.
  • Another Wenet flight, to give some more opportunities for listeners to refine their receiver setups.

Stay tuned!

Next Project Horus Launch – Horus 56 – Sunday 1st May – NOW TELEMETRY ONLY

Update Sunday 1st May: This telemetry-only launch was a great success, with many new stations contributing telemetry! There will be a separate post with information on the flight. We are still planning to perform the imagery flight next weekend, hopefully avoiding Mothers Day.

The AREG’s High-Altitude Ballooning sub-group, Project Horus, is planning their next launch for Sunday the 1st of May, with a planned launch time of 10 AM.

Updated Saturday 30th April

Due to adverse flight path predictions and cloud cover forecasts, the full imagery launch will not occur on Sunday the 1st of May, and will be postponed to the following weekend, (the exact day TBD) conditional on better weather forecasts.

However, since we have a NOTAM (NOtice To Air Missions) approved for the 1st of May, we will make use of it and do a telemetry-only launch, flying a single 70cm telemetry beacon. We are aiming for a maximum altitude of around 27km.

This is a great opportunity for those who have never tracked a Project Horus launch before to get setup to receive telemetry prior to the full-scale launch the following weekend. See below for information on how to receive the telemetry payload.

Live tracking for the flight will be available on the new SondeHub-Amateur tracker, at:!mt=Mapnik&mz=9&qm=1d&mc=-34.91286,139.36396&q=HORUS-V2

We will now be launching from the Mt Barker High School Oval, with the launch team on-site from approximately 9:30AM. Visitors are welcome!

The current flight path predictions have the payload landing to the east of Purnong:

Primary Telemetry – 434.200 MHz

Reprogrammed RS41The primary tracking telemetry will be transmitted on 434.200 MHz using the Horus Binary 4FSK data mode. Amateurs in the Adelaide and Central SA region are also encouraged to get involved with the flight through receiving and uploading flight telemetry from our 70cm band tracking beacons. Every piece of telemetry data is valuable to the flight tracking and recovery teams so if you can help join the distributed receiver network to collect that data you will be making an important contribution to the project!

If you try receiving the telemetry from this flight, you’ll need a SSB-capable 70cm receiver (or a SDR), and the Horus-GUI telemetry decoder software. A brief guide on setting this up is available here:

Note that you will need to use a ‘dial’ frequency of 434.199 MHz for the 4FSK signal to be centred in your receiver passband and hence be decodable.

Tracking Details – Imagery – 443.500 MHz

This payload will not be flying on Sunday the 1st of May. We hope to fly this on our backup launch date of Sunday the 8th of May.

Imagery on this flight will be transmitted via the Wenet downlink system, which uses 115kbit/s Frequency-Shift-Keying to send HD snapshots. Reception of the Wenet imagery requires a Linux computer, a RTLSDR, and a 70cm antenna with some gain (a 5-element Yagi is usually enough).

Imagery received via the Wenet payload from a previous flight.

A guide on how to get set up to receive the Wenet signal is available here:

During the flight, the live imagery will be available at this link:

Next Fox Hunt – Tomorrow Night!

AREG had hoped to hold a combined foot based hunt and picnic in a park for our January hunt however due to the current COVID saga in Adelaide, the committee has decided not to proceed with this, so we have decided to hold our usual car hunt instead – apologies for the late notice.

The hunt will commence from the usual meeting place at the southern end of the car park at the Adelaide Aquatic Centre. Hunters usually meet from 6.15pm and the hunt begins at 6.30pm.

Liaison will be via the Summertown UHF Repeater on 439.900MHz (-5MHz Input with 91.5Hz CTCSS).

As usual, everyone is welcome to join in on the fun, you don’t need to be a member of AREG to participate. We hope you can make it!

December Fox Hunt & Upcoming January BYO Picnic Foot Hunt

Members and friends are advised that our next monthly fox hunt is scheduled for the evening of Friday the 10th of December, kicking off at the car park of the Adelaide Aquatic Centre.

Participants usually meet at the southern end of the car park from around 6.15pm and the foxes (hidden transmitters) are activated at 6.30pm.

Our usual three foxes will be deployed. Two transmit on the 2 metre band and one on the 70cm band.

As usual, participants are free to liaise on the club’s 70cm VK5RSB repeater on 439.900MHz (-5MHz input with 91.5Hz CTCSS).

With the weather warming up, we have also planned a BYO picnic and foot-based hunt for Sunday the 16th of January, at Felixstow Reserve, kicking off at 12pm. For those new to fox hunting who would like to give it a try, there will be equipment available on the day to use if you don’t have your own. Please stay tuned for more details.

UPDATE: Due to the current COVID situation in South Australia the foot-based hunt has been cancelled and been replaced with a car-hunt on the evening of Friday the 14th of January, starting at 6:30PM at the Adelaide Aquatic Centre. The car-based hunts present a considerably lower risk profile than a foot-based hunt and picnic where equipment would need to be shared.

As always, everyone is welcome to join in on the fun, members and non-members alike, so we look forward to seeing you there.

Next fox hunt: Friday 10/09/2021

Our September fox hunt is scheduled for the evening of Friday the 10th of September, kicking off at 6:30pm from the southern end of the car park at the Adelaide Aquatic centre.

As usual, this event is open to all participants and you don’t need to be a member to join us.

This hunt will again see our usual two 2m foxes in use as well the 70cm fox. Our little biscuit tin fox has had an upgrade to a green army ammo tin and SLA battery, donated by Kim VK5FJ. This has increased the Baofeng/Arduino powered fox run time from 3.5 hours to 11+ hours.

Last month’s hunt saw eight of us join in to locate the three foxes. The biscuit tin, deployed by AREG members Chris VK5CP and Gary VK5GRY, was clevery hidden under a witches hat/street cone on Halifax St in the city. Hunters knew they were close when they spotted Chris and Gary seated outside a nearby hotel enjoying a beverage whilst watching the hunters drive up and down trying to locate the transmitter.

The 70cm fox stuck was to the back of a street sign off Greenhill Road, in the Adelaide Parklands whilst the second 2m fox was hidden by the banks of the Torrens River at Grange.

Mark VK5QI’s newly designed TDOA doppler system with car Head Up Display worked extremely well. A video of it in action can be seen here.

Once again, hunters are encourgaed to liaise on the night on the club’s VK5RSB 70cm repeater.

We look forward to seeing you on the night.