• Country
• United States of America (USA)

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

• Year
• 1948–1951

• Category
• Amateur Equipment (Other, but not Key)

• Radiomuseum.org ID
• 87743

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

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

• Wave bands
• - without

• Power type and voltage
• Other, details in remarks or not known. / 6-8 Volt

• Loudspeaker
• - - No sound reproduction output.

• Material
• Metal case

• from Radiomuseum.org
• Model: Signal Meter SM-57 - National Company; Cambridge &

• Shape
• Tablemodel, with any shape - general.

• Notes

• The National Signal Meter SM-57 was an external accessory designed for the National NC-57 receivers. The SM-57 plugs into the rear of the NC-57 chassis by means of octal plug and socket. The SM-57's dial lamp gets its power from the receiver. Has a set-screw needle limit adjustment. The SM-57's cabinet matches the receiver.

• Net weight (2.2 lb = 1 kg)
• 2 lb 0 oz (2 lb) / 0.908 kg

• Price in first year of sale
• 15.00 $

• Source of data
• Shortwave Receivers - Past & Present (3rd ed.)

• Mentioned in
• Allied Catalog 1950 page 11

• Author
• Model page created by Martin Bösch. See "Data change" for further contributors.

• 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)