• Country
• United States of America (USA)

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

• Year
• 1939–1941

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

• Radiomuseum.org ID
• 286063

• • 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
• 203Z 203Z

• Main principle
• Audio-Amplification

• Wave bands
• - without

• Power type and voltage
• Powered by external power supply or a main unit. / 115 Volt

• Loudspeaker
• - - No sound reproduction output.

• Power out
• 300 W (max.)

• Material
• Metal case

• from Radiomuseum.org
• Model: Class B Modulator NT 300 PCW - National Company; Cambridge &

• Shape
• Rack

• Notes

• The National NT 300 PCW Class B Modulator is a component of The National 600 Watt Transmitter. The two 203Z tubes provide 300 watts of modulating power.

• Price in first year of sale
• 127.50 USD

• Mentioned in
• National Company 1941 Catalog

• Literature/Schematics (1)
• Allied Radio Catalog (Knight) (1939 page 101)

• Author
• Model page created by Wayne Childress. 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)