• Country
• United States of America (USA)

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

• Year
• 1930–1932

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 162377

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

• Number of Tubes
• 4

• Valves / Tubes
• 224 224 224 227

• Main principle
• TRF (Tuned-Radio-Frequency but use of regeneration unknown); 2 AF stage(s); Screengrid 1926-1935

• Tuned circuits
• 4 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-29A - National Company; Cambridge &

• Shape
• Chassis only or for «building in»

• Dimensions (WHD)
• 18 x 0 x 13.5 inch / 457 x 0 x 343 mm

• Notes
• The MB-29A four stage tuner in a frosted aluminium chassis. It is for mounting in a console or with electric phonograph combination. There is no rectifier tube mentioned. It is recommended to use it together with the National "245" push-pull amplifier - which has also a field supply for a dynamic speaker. See also the model MB-29 from 1929. See details in the picture text (like "... only until quantity lasts ...) or summaries about the mentioned Lafayette catalog. Lafayette mentiones a list price of $ 69.50 and sells it then for $ 22.50 as "radically reduced!

• Price in first year of sale
• 69.00 $

• Literature/Schematics (1)
• Lafayette Radio Catalog (Lafayette 10th Anniversary catalog 1932, page 34.)

• Author
• Model page created by Ernst Erb. See "Data change" for further contributors.

• 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)