Educational STEM 434.3 MHz Balloon Launch Tuesday 2:30pm

Chris Stubbs M6EDF with 434 MHz trackers

Chris Stubbs M6EDF with 434 MHz trackers

Continuing his Science, Technology, Engineering and Mathematics (STEM) work with schools, Chris Stubbs M6EDF, will launch a balloon STEWARDS-1/CHEAPO-12 for Stewards Academy, Harlow.

The launch will take place at 2:30pm (13:30 GMT) on Tuesday, June 3. Chris will be using a “mini” tracker with 1 AA battery on a 36″ foil balloon and aims to get the balloon to float for a long duration.

It will transmit 50 bps 7n2 RTTY on 434.300 MHz with about 450 Hz FSK and may have a range of up to 500 km depending on altitude.

Chris took the amateur radio Foundation training course run by the Chelmsford Amateur Radio Society (CARS) in January 2013. He is keen on both electronic construction and software development and combines the two interests in High Altitude Ballooning (HAB). Chris has built many tracker payloads for his balloon launches which usually take place from Danbury Common near Chelmsford.

M6EDF CHEAPO Micro TrackerDetails of his high-altitude ballooning hardware and experiments are online at

See online real time tracks and frequencies of this and other 434 MHz balloons at

Beginners Guide to Tracking using dl-fldigi

The role of these 434 MHz balloon launches in teaching maths and science was recently recognised by the Department for Education (DfE) see

Listen to balloons online (when in range of south-east UK) from anywhere in the world with the SUWS 434 MHz WebSDR (select USB)

Check the #highaltitude IRC channel for launch chat. A web client is available at

To get up-to-date information on balloon flights subscribe to the UKHAS Mailing List by sending a blank email to this address:

Chelmsford 434 MHz STEM Balloon Launch

The Chelmsford Amateur Radio Society run training courses for those wishing to get their amateur licence. To find out more speak to Clive G1EUC on
Tel: 01245-224577
Mob: 07860-418835
Email: training2014 at

What is Amateur Radio ?

Post flight update: The balloon floated at an altitude of under 6,000 metres for just over 2 hours.

Flight path of M6EDF's balloon STEWARDS on June 3. 2014

Flight path of M6EDF’s balloon STEWARDS on June 3. 2014