Marconi High Frequency telegraphy/telephony Transmitter Type SWB8E, c. 1935, used at the Cable & Wireless Ltd Engineering Training College, at Porthcurno, Cornwall. Marconi High Frequency telegraphy/telephony Transmitter Type SWB8E circa 1935
Marconi WT Co. valve, type V.24, marked 4137, (RMW/B102* - McVitie Weston number), by Marconi Wireless Telegraph Company Limited. McVitie Weston valve collection, Marconi WT Co Round valve, type V.24
Electro-dynamic microphone, by H. J. Round, Marconi Wireless Telegraph Company, 1922-1923. Round Electro-Dynamic Microphone 1922-1923
Vestigial-sideband filter Type BD 775D made by Marconi's Wireless Telegraph Company Limited, Chelmsford, 1955. This filter formed part of the Independent Television Authority's [ITA] first transmitter at Croydon. In order to accommodation as many televisions transmissions as possible in the available wavebands, some of the 'sideband' frequencies produced by the modulation process are surpressed at the transmitter; the transmission comprises all sideband frequencies lying to one side of the carrier frequency, but only a narrow 'vestige' of those to the other side. The unwanted frequencies are reduced in level by appropriate tuning of the transmitter circuits, but to attain the high defree of suppression necessary to prevent interference with other channels, a unti such as that exhibited is employed. Vestigial-sideband filter, from Croydon Transmitting Station, 1955 1955
Marconi Type HR11 Telegraph Receiving Equipment, serial no. 655259, by Marconi's Wireless Telegraph Co. Ltd., England, c. 1960 Marconi Type HR11 Telegraph Receiving Equipment, c. 1960 1960