• Country
• United States of America (USA)

• Manufacturer / Brand
• Silver - Marshall; Chicago, IL

• Year
• 1931

• Category
• Pre-stage (adaptor for SW/FM/VHF/UHF incl. built-in), Frequency converter

• Radiomuseum.org ID
• 57957

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

• Number of Tubes
• 3

• Valves / Tubes
• 24A 27 80

• Main principle
• Superheterodyne (common); ZF/IF 650 kHz; Screengrid 1926-1935

• Tuned circuits
• 2 AM circuit(s)

• Wave bands
• Short Wave (SW only)

• Power type and voltage
• Alternating Current supply (AC) / 25-60Hz, 100-120; 200-240 Volt

• Loudspeaker
• - - No sound reproduction output.

• Material
• Metal case

• from Radiomuseum.org
• Model: SW Superhet Converter 739 - Silver - Marshall; Chicago, IL

• Shape
• Tablemodel, with any shape - general.

• Dimensions (WHD)
• 13.15 x 8.5 x 6.7 inch / 334 x 216 x 170 mm

• Notes

• Converts these SW bands to the broadcast frequency 650 kHz:

  • 10-20 m
  • 20-40 m
  • 40-80 m
  • 80-160 m

  Transformer primary can be resoldered for 100-120 V or 200-240 V supply voltage.

  Depth stated without knobs

• External source of data
• Ernst Erb

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

• Other Models

• Here you find 225 models, 116 with images and 122 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Silver - Marshall; Chicago, IL