• Country
• United States of America (USA)

• Manufacturer / Brand
• Radio Development Corp.; Springfield, MA

• Year
• 1922

• Category
• Radio part (not a module) 

• Radiomuseum.org ID
• 295443

• Main principle
• Tuner pre 1926 (not a wave trap)

• Wave bands
• Broadcast only (MW).

• Power type and voltage
• No Power needed

• Loudspeaker
• - - No sound reproduction output.

• Material
• Various materials

• from Radiomuseum.org
• Model: Variocoupler - Radio Development Corp.;

• Shape
• Tablemodel, with any shape - general.

• Author
• Model page created by Alan Larsen. See "Data change" for further contributors.

• Other Models

• Here you find 2 models, 2 with images and 0 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Radio Development Corp.; Springfield, MA