VE3KCL WSPR Balloon launch S-6


On 24-Sep-2015 Dave VE3KCL launched a balloon from near Toronto (in fact two hydrogen-filled foil "party" balloons tied together) carrying a 35g payload. The balloon is currently travelling East, about to leave the US East coast. It is cruising at around 8,000m.

The electronics payload Dave built has a GPS, battery, solar panels, QRP Labs Si5351A Synthesiser module, and Arduino Nano (for low weight) that runs the QRP Labs Ultimate3S QRSS/WSPR transmitter firmware, but a slightly modified version.

The balloon uses WSPR on 30m (20mW power) but encodes telemetry data onto the WSPR protocol, in two sequential messages. One is the standard WSPR message. The second encodes the additional data carries 5th and 6th Maidenhead locator characters, altitude, speed, battery, temperature, GPS status and satellite status. The second message type will show up in the database as callsigns whose 1st character is "0" and 3rd character is "1". The other characters and locator and power contain the encoded data, not a valid location.

The balloon is also sending JT9 plain text, and CW to the reverse beacon network. The WSPR messages logged to the WSPRnet database are decoded automatically and plotted on the map in realtime at .

There are more details and photos on

73 Hans G0UPL