81B (81, 81F) Junior Export (220 V)

Philco, Philadelphia Stg. Batt. Co.; USA

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  • Year
  • 1933
perfect model
  • Category
  • Broadcast Receiver - or past WW2 Tuner
  • Radiomuseum.org ID
  • 129468

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

 Technical Specifications

  • Number of Tubes
  • 4
  • Main principle
  • Superheterodyne (common); ZF/IF 460 kHz; Super, reaction, but not adjustable
  • Tuned circuits
  • 3 AM circuit(s)
  • Wave bands
  • Broadcast (MW) and Tropical/Marine/Police Band(s) = 150-200m.
  • Power type and voltage
  • Alternating Current supply (AC) / 220 Volt
  • Loudspeaker
  • Electro Magnetic Dynamic LS (moving-coil with field excitation coil) / Ø 15 cm = 5.9 inch
  • Material
  • Wooden case
  • from Radiomuseum.org
  • Model: 81B Junior [Export ] - Philco, Philadelphia Stg. Batt
  • Shape
  • Table-Cathedral-Type (upright, round top or gothic arch, not rounded edges only).
  • Notes

  • This is an export chassis 81F (or possibly 81E) for 220 V power. Unknown if early or late.

    The domestic models were either in an early version with four controls by 3 knobs (separate controls for tuning, band, power, and volume) or in a later version with three controls by 2 knobs (power and volume combined).

    The 80 series models (models 80, 81, and 84) were referred to as "Philco Junior" and were inexpensive entry-level radios employing a superheterodyne circuit with a regenerative stage to increase gain in the absence of an IF amplifier stage.

    Model 81B is a cathedral with a simple flat-front cabinet. An improvement it offered over the previous model 80B is the inclusion of a second band (police band, 1.5 - 2.8 MHz) with a very simple circuit, in which the oscillator tunes the same range for both bands, and only the front-end RF coil is switched, resulting in the second band being shifted upward in frequency by 920 kHz (twice the IF frequency of 460 kHz). The dial range is extended to accommodate the additional span of the police band.

  • Net weight (2.2 lb = 1 kg)
  • 5.5 kg / 12 lb 1.8 oz (12.115 lb)
  • Circuit diagram reference
  • Rider's Perpetual, Volume 3 = 1933 and before
  • Literature/Schematics (1)
  • - - Manufacturers Literature (Philco 1928-36 Wiring Diagrams, Parts Lists, and Essential Service Data)
  • Author
  • Model page created by Nigel Hulse. See "Data change" for further contributors.

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