434 MHz Balloon Launch at Dorset Rally

Jules G0NZO with the BONZO1 foil balloon

Jules G0NZO with the BONZO1 foil balloons

Jules G0NZO hopes to launch a 434 MHz balloon BONZO8 from the Flight Refuelling ARS Hamfest on Sunday, August 9 at Cobham Sports and Social Club Ground, Merley, near Wimborne, Dorset, BH21 3DA.

The Hamfest lecture stream will start at 11am with a talk on Transverter and RXGEN designs by Kevin Avery G3AAF.

At 11:45am Jules G0NZO will be giving a quick overview of High Altitude Ballooning in the UK and an equipment demonstration. Subject to prevailing weather conditions the launch is planned for 12:30pm and listeners across southern England should be able to tune into the signal on 434.650 MHz USB as well as follow the balloon track online.

The balloon launch will be either a 100gm latex balloon, or a pair of 36″ foil balloons, filled for minimal free lift, to attempt to get the payload to float for the maximum distance. If a latex balloon is used, a simple polythene parachute will be attached, for safety.

Jules G0NZO with the BONZO3 Latex Balloon

Jules G0NZO with the BONZO3 Latex Balloon

The payload is a basic tracking beacon. Radiometrix NTX2 licence exempt transmit module, modulated with RTTY, by a PIC processor and Ublox GPS receiver. Powered by 3xAAA lithium batteries.

BONZO8 Frequency 434.650 MHz USB, ASCII 7 bit RTTY at 50 bps. Approximately 320 Hz shift.

Depending on altitude the 434 MHz transmitter may have a range of around 250 km.

At 1:30pm Essex radio ham Justin G0KSC (InnovAntennas / Force 12) will give a talk on Antennas and at 2:30pm Colin G4KLB will be talking about HamTV from the International Space Station (ISS).

Talk In to the Hamfest will be on 145.550 MHz FM and the gates are open from 10am to 4pm. There is disabled access from 9.30am. Admission is £3.50 and there will be trade stands, a car boot sale, licensed bar as well as lectures. Details from Tony G3PFM on 07743 475018.

Hamfest information http://www.frars.org.uk/cgi-bin/render.pl?pageid=1432

High Altitude Balloon links for online tracking, UKHAS mail list / chat room, WebSDR