Tested on an AVO valve tester, with results shown below. These are badged ‘Marconi’, but have the acid etched date codes of Mullard's Blackburn factory which clearly identifies it as a Mullard tube.
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Original Soviet pentode tubes 6J32P (6Ж32П), manufactured at the Svetlana Factory (Leningrad, USSR).
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This tube was born in 1960 in Hamburg, Germany.
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6267 EF86 CV2901 Valve Tube. Mazda Foreign, Made in USSR. NOS, Supplied in Original Box.
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EF86 Valve Tube. Mullard Foreign.
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They preferred the GEC CV4085 over the Mullard CV2901 as the heater wire in the CV4085 was wound as a double helix with a specified number of turns and pitch as specified by the MOD to minimise the external AC hum.
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We are for honesty and integrity.
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