• Country
• United States of America (USA)

• Manufacturer / Brand
• Kolster; USA

• Year
• 1928

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 45674

• • Brand: International

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

• Number of Tubes
• 8

• Valves / Tubes
• 26 26 26 26 27 26 71A 80

• Main principle
• TRF (Tuned-Radio-Frequency but use of regeneration unknown)

• Tuned circuits
• 4 AM circuit(s)

• Wave bands
• Broadcast only (MW).

• Power type and voltage
• Alternating Current supply (AC) / 100-110; 110-120 Volt

• Loudspeaker
• - This model requires external speaker(s).

• from Radiomuseum.org
• Model: K-21 - Kolster; USA

• Shape
• Tablemodel, with any shape - general.

• Notes

• One dial (primary tuning control knob)

  All schematics show a connection of main power supply to the chassis. We do not always state such cases - since often the uploader does not know.

  Two hum adjusters. Phono jack.

   

• Price in first year of sale
• 160.00 $

• External source of data
• Ernst Erb

• Source of data
• Radio Collector`s Guide 1921-1932

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

• Mentioned in
• Collector's Guide to Antique Radios 4. Edition

• Literature/Schematics (1)
• -- Schematic (La Riparazione degli Apparecchi Radio Delforno-Colciago - Lavagnolo - Italy - 1941)

• Other Models

• Here you find 102 models, 48 with images and 67 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Kolster; USA