door Pye

Chassistype 915.

Considerable research and development went into a new high sensitivity Model 915 for fringe area reception, first seen at the 1939 Radio Show. Interestingly, the Model 915 TV receiver was also a TRF or ‘straight’ receiver design, centred on the BBC TV carrier frequency of 45MHz, and used what at the time was a revolutionary new radio valve of exceptionally high performance. This valve was the famous EF50, developed by Philips at Eindhoven, later to be manufactured by its subsidiary company, Mullard, in the UK.

In May 1939 the Radar development team at Bawdsey were searching for a suitable 45 MHz receiver to replace their prototypes based on an EMI design and the team leader E.G. Bowen was made aware of the Pye TV receiver and CRTs in Cambridge by Professor Edward Appleton. This circuit configuration became the core of all British VHF airborne radar receivers.

When World War II began on 3rd September 1939, UK TV broadcasting came to an end, as did the production of the 45 MHz Pye Model 915 TV receiver, and Pye was switched over to the design and production of first radar and later, wireless equipment, for the British Military (bron www.pyemuseum.org)

from Wireless World