- Item type
- Object
- Provenance
- Presented by the Marconi Corporation.
- Primary inscriptions
- "MOV / CO LTD" printed on underside of base. "This Valve has been thoroughly tested before leaving / works. Its filament emission was not less than 5 / millimaps at 1.8 Volts. Fil volts1.5-2.0 / Fil. amps .3-.35. Anode volts 20-80. Filament / should be kept as cool as possible when working and / at NO TIME should more than 2 volts be applied" printed on label glued around base.
- Object type
- Radio valve
- Dimensions
- Diameter: 40mm Height: 105mm Weight: 0.05kg
- Inventory No
- 80189
- Accession Number
- 2004-9/357
Description
Marconi Radio Valve (or Tube) Type DER (Dull Emitter R) with mostly silvered 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. Previously catalogued with two other, similar Type DER Radio Valves (Inv. Num.s 15591, 43964).
Related Items
More related items- Marconi Radio Valve Type DER, by Marconi Company, London, c.1925Inventory Number 94119
Marconi Radio Valve Type DER, by Marconi Company, London, c. 1925Inventory Number 15591
Marconi-Osram Radio Valve Type DER, by Marconi Company, London, c. 1923Inventory Number 48922
Marconi-Osram Radio Valve Type DER, by Marconi Company, London, c. 1923Inventory Number 43964