Ancillary Equipment, Valve Type CV12 Thyratron, Type 227 Radar, British
Admiralty Valve Type CV12, dated July 1943. War Office serial ZC/CV12 and Admiralty serial W3205, dated July 1943, for Admiralty use. The CV12 is a mercury vapour (gas relay) thyratron valve developed by GEC as experimental Type E1191 for use as a pulse modulator in the Royal Navy Type 277 radar in service from 1943. The newly developed cavity magnetron Type CV76 was the power valve generating the microwave energy.
BTH also made the CV12 and modified their Type BT49.
The pulses generated for the magnetron were 2 μs long and repeated 500 times a second.
The 500kw 10cm Type 227 radar was developed to meet a requirement for low cover and height finding, and was capable of detecting a low-flying aircraft at a range of 25 miles and calculate its altitude.