• Country
• United States of America (USA)

• Manufacturer / Brand
• Zenith Radio Corp.; Chicago, IL

• Year
• 1953

• Category
• Medical Technology

• Radiomuseum.org ID
• 73940

• • alternative name: Chicago Radio Lab

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

• Number of Transistors
• 3

• Semiconductors
• CK718 CK718 CK718

• Main principle
• Audio-Amplification

• Wave bands
• - without

• Details
• Hearing aid

• Power type and voltage
• Dry Batteries / 1.5 Volt

• Loudspeaker
• - only for Earphone!

• Material
• Metal case

• from Radiomuseum.org
• Model: Royal-T Hearing Aid - Zenith Radio Corp.; Chicago,

• Shape
• Very small Portable or Pocket-Set (Handheld) < 8 inch.

• Notes
• Worlds first transistorised hearing aid, introduced Oct.1953; a single 1.5Volt "N" cell allowed operation for ca 15 cents a month, while comparable tube models operated at $4.50 to $9.00 a month. The following year 1954 brought already five successive transistorised models;

• Mentioned in
• Zenith Transistor Radios

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

• Other Models

• Here you find 4496 models, 4101 with images and 3615 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Zenith Radio Corp.; Chicago, IL