• Year
  • 1937/1938
perfect model
  • Category
  • Broadcast Receiver - or past WW2 Tuner
  • Radiomuseum.org ID
  • 39873
    • alternative name: FMC
    • Brand: Welco

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 456 kHz; 2 AF stage(s)
  • Tuned circuits
  • 6 AM circuit(s)
  • Wave bands
  • Broadcast only (MW).
  • Power type and voltage
  • Storage and/or dry batteries / 2V & 4.5V & 136 Volt
  • Loudspeaker
  • Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil)
  • Material
  • Metal case
  • from Radiomuseum.org
  • Model: 4A [Chassis Only] - Fairbanks, Morse & Co.;
  • Shape
  • Chassis only or for «building in»
  • Notes
  • The Fairbanks Morse 4A is an Battery operated, 4 tube BC band chassis used in various models. BC band frequency range is 540 to 1730kHz. Has bias cell used to bias 1F7G tube.  Also has AVC and 2 stage audio circuit.

    The 4A and 4B chassis are the same chassis, however the 4A chassis came with a battery cable used to interface with standard A, B and C batteries, while the 4B chassis came with a synchronous vibrator power supply and cable used to interface with a 6V storage battery. Both the battery cables and the vibrator power supply have plugs, making them interchangable to the chassis.

    NOTE: 4A is the chassis number and NOT the model number.  Please post pictures of the radio's on the appropriate radio model page and NOT to this page.

    The following models use the 4A and 5A chassis and schematic:

    Model Number Chassis Batteries Needed Cabinet
    4AT5B 4A Standard A, B, C Table Model
    4AC1B 4A Standard A, B, C Console
    4BT5B 4B 6V Storage Table Model
    4BC1B 4B 6V Storage Console


     

  • External source of data
  • Ernst Erb
  • Circuit diagram reference
  • Rider's Perpetual, Volume 9 = 1938 and before
  • Literature/Schematics (1)
  • - - Manufacturers Literature (Fairbanks Morse Service Notes Chassis Models 4A & 4B)

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