Large metal Iolanda switchboard with 2 meters (No. 60939), made by Marconi's Wireless Telegraph Company Limited, Chelmsford, Essex, England, 1900-1950 Metal Iolanda switchboard, 1900-1950 1900-1950
Tuned components of Marconi SWB18 h.f. transmitter (final r.f. amplifier stage) mounted on truck, c. 1945 Tuned components of Marconi SWB18 h.f. transmitter (final r.f. amplifier stage) mounted on truck
Iconoscope, made by Dr V K Zworykin in his laboratory on 9 November 1931, successfully tested the next day. Prototype Iconoscope tube, 1931