Horus 73 Takes Amateur Radio into the Stratosphere

The Amateur Radio Experimenters Group (AREG) in Adelaide is preparing for another ambitious Project Horus high-altitude balloon launch on Sunday 30 August, with Horus 73 scheduled to lift off from Mt Barker at around 10:00 am ACST. The balloon is expected to climb beyond 30 kilometres, potentially providing radio coverage across hundreds of kilometres of South Australia and western Victoria. The headline payload is an experimental 2 metre to 70 centimetre cross-band FM repeater, operating on 145.075 MHz uplink with 91.5 Hz CTCSS and 438.975 MHz downlink. The repeater will operate as a controlled net through club station VK5ARG, with operators asked to listen for net control before transmitting. AREG advises that a directional antenna will be useful towards the limits of the balloon's enormous radio horizon.

But voice is only part of the experiment. Horus 73 will also carry a 916.575 MHz MeshCore LoRa repeater using the Australia (Narrow) preset, with the fascinating possibility of relaying MeshCore messages between the Victorian network and South Australia. The balloon will additionally carry AREG's Wenet digital imaging system on 443.5 MHz, transmitting live images from the stratosphere, together with Horus Binary 4FSK telemetry on 434.200 and 434.210 MHz. This gives amateurs plenty of ways to participate, from making a voice contact and experimenting with long-distance LoRa through to receiving telemetry and decoding live imagery. AREG says every uploaded telemetry packet also contributes to the distributed tracking network used by the flight and recovery teams.

Project Horus is a particularly good example of amateur radio as an experimental service. In one flight it combines VHF/UHF propagation, digital telemetry, SDR reception, LoRa mesh networking, live digital imagery, antennas, tracking and high-altitude engineering. Previous Horus flights have demonstrated just how effective the distributed amateur receiving network can be, including reception across South Australia and Victoria. So charge the handheld, point the Yagi towards the balloon and fire up the SDR. There are considerably less entertaining ways to spend a Sunday morning than bouncing your signal off a radio repeater floating more than 30 kilometres above the Earth.

AREG Horus 73 launch information and participation details - Link

Image sourced from the AREG website story.

Page Last Updated: Saturday, 29 Aug 2026 at 21:09 hours by Justin Giles-clark

Click Here To Return To Previous Page