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Record Details

Mullard Radio Valve Type PM4, by Mullard, English, 1930s

preview image for Mullard Radio Valve Type PM4, by Mullard, English, 1930s
Inventory Number: 21856
Object Type:
Place Created: England United Kingdom Europe
Accession Number: 2004-9/338
Brief Description: Mullard Audio Output Radio Valve (or Tube) Type PM4 with glass balloon envelope. Glass surface half-silvered and half-blackened probably during manufacturing process. The Type PM4 had a tapered-tubular bulb, with bottom seal, types, polished black bakelite base and four steel B4/M base pins.
Primary Inscriptions: "REGISTERED / TRADE MARK / MULLARD / RADIO VALVES / PROTECTED BY PATENTS / 1128" printed on exterior surface of bulb. "MULLARD / PM4 / [TRADEMARK] / REGISTERED TRADE MARK" printed on exterior surface of bulb.
Provenance: Presented by the Marconi Corporation.
Collection Group: Marconi Collection
Material(s): Glass
steel
bakelite
assorted metals.
plastic
Dimensions:
Height Width Depth Diameter Unit
100 40 mm

Narratives

Image with multimedia irn 35373Image with multimedia irn 35374

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