A78RG

Murphy Radio Ltd.; Welwyn Garden City

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  • Year
  • 1939/1940
  • Category
  • Broadcast Receiver - or past WW2 Tuner
  • Radiomuseum.org ID
  • 171103

Click on the schematic thumbnail to request the schematic as a free document.

 Technical Specifications

  • Number of Tubes
  • 12
  • Main principle
  • Superhet with RF-stage; ZF/IF 465 kHz; 2 AF stage(s)
  • Tuned circuits
  • 9 AM circuit(s)
  • Wave bands
  • Broadcast, Long Wave and more than two Short Wave bands.
  • Details
  • Changer (Record changer)
  • Power type and voltage
  • Alternating Current supply (AC) / 200-250 Volt
  • Loudspeaker
  • Electro Magnetic Dynamic LS (moving-coil with field excitation coil)
  • Power out
  • 15 W (unknown quality)
  • Material
  • Wooden case
  • from Radiomuseum.org
  • Model: A78RG - Murphy Radio Ltd.; Welwyn
  • Shape
  • Console, Lowboy (legs < 50 %).
  • Notes
  • Design by Eden Minns. Two different RF-stages: On shortwave a SP41 is used as an RF-amplifier, on MW/LW a VP41. SW is restricted to Bandspread-tuning of 13, 16, 19, 21, 31, 41 and 49 m bands plus VHF Band 1 (45 MHz) for television sound only. This was of use only in the London area, but gave very good audio range. Variable selectivity in four stages, giving audio range of 8000, 5000, 4000 and 3000 Hz bandwidth. In the two lower positions, an additional IF valve (VP41) is switched into the circuit, in order to improve gain and selectivity. In the higher positions, noise suppression is automatically introduced. Two LF stages. New alphabetical tuning with stations grouped according to wavebands, individually illuminated. Cathode ray tuning indicator. Wire remote control RA80 with push button tuning giving 2 LW-stations and 4 MW-stations and volume control. Wire up to 12 feet long, winds itself up after use. Record changer with piezo-electric pickup. Handles up to eight mixed 10 or 12 in. records. Loudspeaker specially developed for this model. Acoustic tunnel as in A40RG: Walls around speakers from front to back, dampened by felt. Arrangement should restrict the outlet of sound to an aerea similar to that of the combined areas of the diaphragms of both loudspeakers. Built in tilted upwards and outwards. This arrangement was supposed to give spartial -"stereoscopic" - effect, according to the manufacturer and one contemporary test report. Two chassis used, power and output valves in chassis at the base of the cabinet. Two lids. Cabinet of Bombay rosewood, top thuya burr. Power consumption 220watts Price when new £90. Price change December 1939: £95. PT (Purchase Taxe) payable from October 1940. No surviving A78RG is known.
  • Price in first year of sale
  • 90.00 GBP
  • Source of data
  • - - Manufacturers Literature
  • Mentioned in
  • The Gramophone, 5/1940, S.433f.
  • Author
  • Model page created by Sönke Gäthke. See "Data change" for further contributors.

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