UK 434 MHz balloons over Central Europe

A Raspberry Pi computer board

A Raspberry Pi computer board

On Saturday, April 13 at 1000 UT, two balloons both carrying 434 MHz transmitters were launched from Cambridge, UK . One transmitting video images from a Rapsberry Pi computer board, the other carried a 144.800 MHz APRS beacon M0UPU-11 in addition to the 434 MHz beacon.

The first balloon PIE5 is flying a Raspberry Pi computer board which transmitted live Slow Scan Digital Video (SSDV) images back to the ground by a pair of transmitters to double the bandwidth. The data was RTTY 300 baud 8N2. The frequencies used were 434.070 and 434.074 MHz. The balloon call sign was $$PIE.

The second balloon AVA flew a 70cms tracker on 434.450 MHz 50 baud 7N2. Additionally once it entered air space where the airborne use of APRS is permitted a second APRS transmitter was enabled (the APRS frequency is 144.800 MHz) with the call sign M0UPU-11.

The balloons had been expected to head for Poland and on Saturday evening they were over Germany but by early Sunday morning PIE5 was over Switzerland and AVA was over Austria.

The 434 MHz downlinks  on the balloons are generated using Radiometrix NTX2 transmitter modules, the batteries were expected to last 24 hours.

A third balloon callsign XABEN transmitting on 434.350MHz, 470Hz shift, 7N1 was also launched. Tthis was configured to have a short lifetime, going straight-up until the balloon burst rather than floating at 30km across Europe.

Live video of the launch was streamed by the British Amateur TV Club (BATC) at

Tracks of both balloons are at

Direct link to M0UPU-11 APRS track!call=a%2FM0UPU-11&timerange=86400&tail=86400

Images from the PIE5 Raspberry Pi balloon transmitted using SSDV can be seen at

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Beginners Guide to Tracking using dl-fldigi

Digital Slow Scan Video