• Country
• Czechoslovakia

• Manufacturer / Brand
• Tesla; Praha, Bratislava etc.

• Year
• 1965 ?

• Category
• Medical Technology

• Radiomuseum.org ID
• 359809

• • Brand: Supraphon

• Number of Transistors
• Semiconductors present.

• Semiconductors

• Main principle
• Audio-Amplification

• Wave bands
• - without

• Details
• Hearing aid

• Power type and voltage
• Dry Batteries / 2,5 Volt

• Loudspeaker
• - only for Earphone!

• Material
• Various materials

• from Radiomuseum.org
• Model: Tranzistorový sluchadlo - Transistorized Hearing Aid ALS 311 - Tesla; Praha, Bratislava etc.

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

• Dimensions (WHD)
• 49 x 73 x 17 mm / 1.9 x 2.9 x 0.7 inch

• Notes

• Improved version of ALS 310.

• Net weight (2.2 lb = 1 kg)
• 0.055 kg / 0 lb 1.9 oz (0.121 lb)

• Mentioned in
• -- Original prospect or advert

• Author
• Model page created by Gabriel Toth. See "Data change" for further contributors.

• Other Models

• Here you find 1874 models, 1197 with images and 680 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Tesla; Praha, Bratislava etc.