• Country
• United States of America (USA)

• Manufacturer / Brand
• Holtzer-Cabot Electric Co., (The); Boston, Massachusetts

• Year
• 1923 ?

• Category
• Loudspeaker, headphone or earphone

• Radiomuseum.org ID
• 138268

• Wave bands
• - without

• Power type and voltage
• No Power needed

• Loudspeaker
• - Is a Headphone or Earphone

• Material
• Various materials

• from Radiomuseum.org
• Model: No.4 National Headphones - Holtzer-Cabot Electric Co.,

• Price in first year of sale
• 6.00 $

• Literature/Schematics (1)
• Ad in Radio News, March 1924

• Literature/Schematics (2)
• Radio Broadcast, Dec. 1923, p. 177

• Author
• Model page created by Konrad Birkner † 12.08.2014. See "Data change" for further contributors.

• Other Models

• Here you find 7 models, 6 with images and 0 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Holtzer-Cabot Electric Co., (The); Boston, Massachusetts