Hivac
of South Ruislip. The first UK company to manufacture a miniature valve.
1934 Paul Freedman was granted an exemption under the Aliens Restrictions Act, in respect of Industrial Development Laboratories, engaged in Research and Development of New Products; 6, Hillside Gardens, Highgate, N.6[1]
1930s Established as the Freedman Valve Co
Name changed to the High Vacuum Valve Co, later Hivac
1939 Private company. Automatic Telephone and Electric Co took a controlling interest in Hivac as basis for facilities for electronic development in telecommunications[2].
1944 Automatic Telephone and Electric Co gained full control of Hivac[3].
1945 First patent to Hivac, with Alexander R. Rangabe, on electronic tube.
By 1949 manufacturer of miniature and midget thermionic valves for deaf aids, etc
1961 Manufacturers of thermionic and electronic devices, including subminiature valves, cold cathode tubes, filamentary and neon indicator lamps. 700 employees. [4]