- Item type
- Object
- Provenance
- Presented by the Marconi Corporation.
- Primary inscriptions
- "MARCONI OSRAM VALVE / MADE AT THE OSRAM LAMP WORKS / COVERED BY VARIOUS PATENTS" printed on exterior surface of bulb. "BBC [LOGO] / D.E.R. / 16942" printed on exterior surface of bulb. "Fil. Volts 1.8-2.0 Fil. Amps 0.4 av. Anode Volts 30-50 / This Valve has been thoroughly tested before leaving the / Works, and no responsibility can be accepted for Valves / used under conditions other than the above." printed on label attached to lower exterior surface of bulb.
- Object type
- Radio valve
- Dimensions
- Diameter: 50mm Height: 110mm
- Inventory No
- 48922
- Accession Number
- 2004-9/355
Description
Marconi Radio Valve (or Tube) Type DER (Dull Emitter R), with glass balloon envelope, steel-plated plastic? base and four brass? base pins. The construction was of a cylindrical anode with a helical grid passing through it, threaded by a filament.
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