Arthur Butcher G3KPJ at the Chelmer Institute (Mid-Essex Technical College) with the base station for mobile telephone system

Development of Mobile Phone by Chelmsford Radio Amateurs

The vintage BBC TV Tomorrow's World clips now available on the web contains one that shows the results of the pioneering work of Chelmsford Radio Amateurs who developed one of the early mobile phones 30 years ago.

The base station for mobile telephone system was developed by Chelmsford Radio Amateur Lew Schnurr K0BUO/G5AAN (later G0AAN).

Arthur Butcher G3KPJ and Geoff Mills G3EDM also worked on the project in 1979 at the Chelmer Institute, formerly the Mid-Essex Technical College, Victoria Road South, Chelmsford.

The mobile part of the system used a modified Amateur Radio 2 metre portable Yaesu FT202 1 watt FM transceiver running half-duplex on channels in the 140 and 153 MHz bands using an experimental licence. From the portable FM transceiver it was possible to both make and receive telephone calls.

In those days the telephone network used a pulse dialling system, so when a number was dialled the carrier of the transceiver was pulsed on and off.

This system was developed many years before the mobile (cell) phone networks were created and it was featured on the BBC TV programme "Tomorrow's World" broadcast on September 13, 1979.

Watch the Tomorrow's World Video, partly recorded in Danbury Park near Chelmsford, at
http://www.bbc.co.uk/archive/tomorrowsworld/
8018.shtml?all=2&id=8018

Chelmsford Amateur Radio Society
http://www.g0mwt.org.uk/