• Country
• United States of America (USA)

• Manufacturer / Brand
• Watkins Johnson Company, Gaithersburg (MD)

• Year
• 1967

• Category
• Commercial Receiver (may include amateur bands)

• Radiomuseum.org ID
• 89299

• Number of Transistors
• Semiconductors present.

• Semiconductors

• Main principle
• Superheterodyne (common)

• Wave bands
• Wave Bands given in the notes.

• Power type and voltage
• Alternating Current supply (AC) / 115/230 Volt

• Loudspeaker
• - For headphones or amp.

• Material
• Metal case

• from Radiomuseum.org
• Model: 521A-3 - Watkins Johnson Company,

• Shape
• Rack

• Dimensions (WHD)
• 19 x 3.5 x 18 inch / 483 x 89 x 457 mm

• Notes
• sw / vhf receiver, coverage 20 - 80 MHz, FM, AM, CW (BFO);
  tuned via steel tape dial;
  features internal panoramic display, sweep width 300 kHz;
  in same rack with DRO-290A-1 digital frequency readout with nixie tubes.
  Swiss Military model number E-649.

• Source of data
• - - Data from my own collection

• Author
• Model page created by Martin Bösch. See "Data change" for further contributors.

• Other Models

• Here you find 18 models, 9 with images and 1 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Watkins Johnson Company, Gaithersburg (MD)