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History of Science Museum

Marconi Radio Valve Type D42, by Marconiphone Company, English, 20th Century

Inventory Number 80037


Acknowledgement: © History of Science Museum, University of Oxford, inv.80037

Item type
Object
Provenance
Presented by the Marconi Corporation.
Primary inscriptions
"THE MARCONIPHONE CO. LTD. / MARCONI / B.V.A." printed on transfer stuck to exterior surface of bulb. "D42 / MADE & PATENTED / IN ENGLAND" printed on exterior surface of bulb.
Object type
Radio valve
Dimensions
Diameter: 30mm Height: 80mm Weight: 0.05kg
Inventory No
80037
Accession Number
2004-9/348

Description

Marconi Radio Valve Type D42, in glass balloon envelope. With partially silvered surface, probably due to manufacturing process. Upon polished black bakelite? base with four steel base pins. Marconiphone Co. Ltd. was founded in December 1923 so valve can be dated post-1923.