• 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
• 49614

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

• Number of Tubes
• 3

• Valves / Tubes
• 35 35 27

• Main principle
• TRF with regeneration; 1 AF stage(s)

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

• Power type and voltage
• Powered by external power supply or a main unit. / 2,5 / 135-180 Volt

• Loudspeaker
• - For headphones or amp.

• Material
• Metal case

• from Radiomuseum.org
• Model: SW-3 Model I [var 1b] - National Company; Cambridge &

• Shape
• Tablemodel, with any shape - general.

• Notes
• plug-in coils series "10-22" for coverage 90 - 35000 kHz;
  headphones operation only, no audio output stage
  the first SW-3 radios came in the cabinet but have been wired externally ("Jackson Laboratories", a National affiliated enterprise), due to licensing reasons . Amateur bandspread coils standard equipment. Matching power supply is 5880.

• Price in first year of sale
• 55.00 $

• External source of data
• Ernst Erb

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

• Mentioned in
• QST Dec.1931, p.2

• Other Models

• Here you find 445 models, 284 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)