• Country
• United States of America (USA)

• Manufacturer / Brand
• Columbia Phonograph, American / Volta Graphophone Company; USA

• Year
• 1931/1932 ?

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 35670

• • alternative name: American Graphophone || Columbia Recording

• Number of Tubes
• 5

• Valves / Tubes
• 51 51 24 47 80

• Main principle
• TRF without regeneration

• Tuned circuits
• 3 AM circuit(s)

• Wave bands
• Broadcast only (MW).

• Power type and voltage
• Alternating Current supply (AC)

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

• Material
• Wooden case

• from Radiomuseum.org
• Model: C-31 - Columbia Phonograph, American

• Shape
• Tablemodel, Tombstone = decorative upright, not cathedral but can have rounded edges.

• External source of data
• Ernst Erb

• Source of data
• Radio Collector`s Guide 1921-1932

• Mentioned in
• The Radio Collector's Directory and Price Guide 1921 - 1965

• Literature/Schematics (1)
• Rider's Perpetual, Volume 2 = 1932 and before (2-1,2)

• Literature/Schematics (2)
• Cathedral & Tombstone Radios (page 75.)

• Literature/Schematics (3)
• Table Top Radios Vol. 4 Stein 2003 (page 63.)

• Other Models

• Here you find 118 models, 84 with images and 34 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Columbia Phonograph, American / Volta Graphophone Company; USA