Hivac









of South Ruislip. The first UK company to manufacture a miniature valve.
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[1].
1944 Automatic Telephone and Electric Co gained full control of Hivac[2].
1961 Manufacturers of thermionic and electronic devices, including subminiature valves, cold cathode tubes, filamentary and neon indicator lamps. 700 employees. [3]