• Country
• United States of America (USA)

• Manufacturer / Brand
• High Frequency Laboratories (HFL); Chicago, IL

• Year
• 1928

• Category
• Power supply/conditioner or battery or charger 

• Radiomuseum.org ID
• 44354

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

• Number of Tubes
• 1

• Valves / Tubes
• UX280

• Wave bands
• - without

• Loudspeaker
• - - No sound reproduction output.

• Material
• Metal case

• from Radiomuseum.org
• Model: Isotone 10 - High Frequency Laboratories

• Dimensions (WHD)
• 11 x 8.5 x 10 inch / 279 x 216 x 254 mm

• Price in first year of sale
• 95.00 $

• External source of data
• Ernst Erb

• Circuit diagram reference
• Rider's Perpetual, Volume 1 = 1931/1934 (for 1919-1931)

• Literature/Schematics (1)
• Walter Ashe Radio Co. catalogue for season 1928-1929

• Other Models

• Here you find 32 models, 10 with images and 6 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from High Frequency Laboratories (HFL); Chicago, IL