• Country
• United States of America (USA)

• Manufacturer / Brand
• Philco, Philadelphia Stg. Batt. Co.; USA

• Year
• 1933

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 51170

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

• Number of Tubes
• 4

• Valves / Tubes
• 77 77 42 80

• Main principle
• Superheterodyne (common); ZF/IF 460 kHz; Super, reaction, but not adjustable

• Wave bands
• Broadcast (MW) and Tropical/Marine/Police Band(s) = 150-200m.

• Power type and voltage
• Alternating Current supply (AC) / 115 Volt

• Loudspeaker
• Electro Magnetic Dynamic LS (moving-coil with field excitation coil)

• Material
• Wooden case

• from Radiomuseum.org
• Model: 81Junior [Late ] - Philco, Philadelphia Stg. Batt

• Shape
• Table-Cathedral-Type (upright, round top or gothic arch, not rounded edges only).

• Dimensions (WHD)
• 12 x 14 x 8 inch / 305 x 356 x 203 mm

• Notes

• 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.
  
  There was an early version with four controls by 3 knobs (separate controls for tuning, band, power, and volume) and this later version with three controls by 2 knobs (power and volume combined).

  There was also an export chassis version 81F (or possibly 81E) for 220 V power.

• Price in first year of sale
• 19.00 $

• External source of data
• Ernst Erb

• Source of data
• Collector's Guide to Antique Radios 4. Edition

• Circuit diagram reference
• Rider's Perpetual, Volume 3 = 1933 and before

• Mentioned in
• Guide to Old Radios (Philco Radio 1928-1942 (Ramirez))

• Literature/Schematics (1)
• Rider's Perpetual, Volume 8 = 1937 and before (Philco 1928-36 Wiring Diagrams, Parts Lists, and Essential Service Data)

• Other Models

• Here you find 4019 models, 2215 with images and 3667 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Philco, Philadelphia Stg. Batt. Co.; USA