• Country
• United States of America (USA)

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

• Year
• 1929 ?

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 49580

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

• Number of Tubes
• 5

• Valves / Tubes
• 24 24 24 24 27

• Main principle
• TRF (Tuned-Radio-Frequency but use of regeneration unknown)

• Tuned circuits
• 8 AM circuit(s)

• Wave bands
• Broadcast only (MW).

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

• Loudspeaker
• - For headphones or amp.

• Material
• Metal case

• from Radiomuseum.org
• Model: MB-30 - National Company; Cambridge &

• Shape
• Chassis only or for «building in»

• External source of data
• Ernst Erb

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

• 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)