Radio Valves

Marconi 'Osram' DE4

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Marconi 'Osram' DE4 dull emitter (thoriated tungsten) filament triode, probably from before 1925. A 1925 example at the National Valve Museum has a bakelite base. The valve bears a 'BBC' mark, (second picture above) of the style used from 1924 to 1927 and the serial number 'W1512'.


© Andy Cowley, 2005-2012     Home

This page last modified by AJC on Friday, 26-Mar-2010