Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 134,776 pages of information and 213,825 images on early companies, their products and the people who designed and built them.
of South Ruislip. The first UK company to manufacture a miniature valve.
1930s Established as the Freedman Valve Co
1961 Manufacturers of thermionic and electronic devices, including subminiature valves, cold cathode tubes, filamentary and neon indicator lamps. 700 employees.