• Country
• United States of America (USA)

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

• Year
• 1936

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 141805

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

• Number of Tubes
• 15

• Valves / Tubes
• 78 6B7 76 78 78 78 85 85 85 6F7 42 6A3 6A3 5Z3 80

• Main principle
• Superhet with RF-stage; ZF/IF 460 kHz

• Wave bands
• Broadcast, Long Wave and 2 x Short Wave.

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

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

• Power out
• 20 W (unknown quality)

• Material
• Wooden case

• from Radiomuseum.org
• Model: 680X [Late] - Philco, Philadelphia Stg. Batt

• Shape
• Console with any shape - in general

• Notes
• The Philco model 680X is an elaborate 15-tube 4-band high fidelity radio. It has the highest output power of any of Philco's radios up to 1936, with a push-pull class A triode output stage using two 6A3 triodes driven by a 42 pentode. In addition to the 5Z3 rectifier for the B+, there is a second rectifier using a type 80 tube to provide fixed negative bias to the output tubes.
  
  Other features for high fidelity include the use of passive radiator speakers (called "Acoustic Clarifiers") in addition to the main driven speaker, a separate bass amplifier stage using a 6F7 tube, and variable coupling in all three IF transformers to trade off selectivity versus high frequency audio response.
  
  Other notable features of the circuitry include two IF stages, separate oscillator and mixer tubes, use of an amplified AVC, and a dedicated tube and separate IF transformer for providing the signal to the shadow meter.
  
  The early version (1935) of the 680X has the controls under a lid on the top of the cabinet. The late version (1936) has a more conventional appearance with the controls on the front of the cabinet.

• Price in first year of sale
• 275.00 $

• Source of data
• Philco Radio 1928-1942

• Circuit diagram reference
• Rider's Perpetual, Volume 7 = 1936 and before

• Literature/Schematics (1)
• Philco Service Bulletin # 228; Philco Wiring Diagrams, Parts Lists, and Essential Serv. Data 1928-36

• Literature/Schematics (2)
• Pre-War Consoles

• Author
• Model page created by Thomas Albrecht. See "Data change" for further contributors.

• Other Models

• Here you find 4006 models, 2205 with images and 3656 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Philco, Philadelphia Stg. Batt. Co.; USA