• Country
• United States of America (USA)

• Manufacturer / Brand
• Sprague Electric Company; North Adams, MA

• Year
• 1952

• Category
• Service- or Lab Equipment

• Radiomuseum.org ID
• 99484

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

• Number of Tubes
• 3

• Valves / Tubes
• 12J5GT 1619 1629

• Wave bands
• - without

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

• Loudspeaker
• - - No sound reproduction output.

• Material
• Metal case

• from Radiomuseum.org
• Model: TO-4 Tel-Ohmike - Sprague Electric Company;

• Shape
• Tablemodel, with any shape - general.

• Dimensions (WHD)
• 14.6 x 8.9 x 6.1 inch / 371 x 226 x 155 mm

• Notes
• Tel-Ohmike Capacitor-Resitor Bridge.

• Net weight (2.2 lb = 1 kg)
• 12 lb 8 oz (12.5 lb) / 5.675 kg

• Price in first year of sale
• 72.00 $

• Literature/Schematics (1)
• Allied Radio Catalog Nº 150, 1956

• Literature/Schematics (2)
• Sprague Model TO-4 Operating Manual, printed in 1954.

• Author
• Model page created by Vitor Oliveira. See "Data change" for further contributors.

• Other Models

• Here you find 11 models, 10 with images and 6 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Sprague Electric Company; North Adams, MA