RSGB Balloon Challenge

Report by Philip, G4GHZ, Programme Secretary.

The Radio Society of Harrow participated in the RSGB Long Range Balloon Challenge from outside the club house in Bushey. Myself and Don G0ACK operated, using a Heltec Tracker purchased from the SOTA shop, connected to a 6 element Yagi. Whilst we were unsuccessful in contacting the balloon it was a fun morning. Looking at the map on the EA LoRa APRS website no-one in the Hertfordshire/London area seemed to have contacted the balloon - the nearest two stations to us that did were 20 to 30 miles to the West.

After the contest, I asked some questions on the balloon forum. Here’s some feedback:

1 The reason we didn't get through may have been due to QRM on the frequency because of everyone trying to get through.

2 We were within the balloon coverage area as at the height of 40,000 feet or so someone calculated a 400km coverage radius.

3 We could have monitored and demodulated the downlink frequency traffic to check if we were pointing at the balloon, if other available software that supported half-duplex operation had been installed in the tracker. However the software that was promoted for the competition was only simplex. Something to try next time.

Someone on the forum was advised that only a very low angle of antenna elevation should be used, and quoted 9 degrees elevation at 50 km from the balloon. If correct, that implies at the distance the club was from the balloon the optimum elevation would only be a few degrees.