Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 148,518 pages of information and 233,949 images on early companies, their products and the people who designed and built them.
1974. of Ilford, Essex. Managing director— F. K. Chorley; sales manager avionics— M. I. Dodd. Airborne UHF/VHF transmitter/receivers—PTR175, PTR377, PTR1721 and PTR170 (UHF only); airborne integrated data acquisition and recording systems including advanced large-capacity PV740 system for the Boeing 747, PV1573 system for ARINC 573 for Concorde and wide-bodied aircraft and comprehensive flight-test systems; aircraft weapon control and stores management systems; missile guidance systems; radar altimeters; target aircraft telecommand systems. 
Part of Plessey Co