• Country
• United States of America (USA)

• Manufacturer / Brand
• National Company; Cambridge & Malden (MA)

• Year
• 1931 ??

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 49608

• • alternative name: National Toy Co.
  • Brand: Thrillbox

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

• Number of Tubes
• 2

• Valves / Tubes
• 222 112A

• Main principle
• TRF with regeneration

• Tuned circuits
• 1 AM circuit(s)

• Wave bands
• Short Wave (SW only)

• Power type and voltage
• Storage and/or dry batteries / 6 & 45 & 67 & 135 Volt

• Loudspeaker
• - This model requires external speaker(s).

• from Radiomuseum.org
• Model: SG Short Wave Tuner - National Company; Cambridge &

• External source of data
• Ernst Erb

• Circuit diagram reference
• Rider's Perpetual, Volume 1 = 1931/1934 (for 1919-1931)

• Other Models

• Here you find 446 models, 285 with images and 189 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from National Company; Cambridge & Malden (MA)