• Country
• United States of America (USA)

• Manufacturer / Brand
• Hewlett-Packard, (HP); Palo Alto, CA

• Year
• 1966 ??

• Category
• Service- or Lab Equipment

• Radiomuseum.org ID
• 127623

• Number of Tubes
• 45

• Valves / Tubes

• Wave bands
• - without

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

• Loudspeaker
• - - No sound reproduction output.

• Material
• Metal case

• from Radiomuseum.org
• Model: Electronic Counter 521C - Hewlett-Packard, HP; Palo Alto

• Shape
• Tablemodel, low profile (big size).

• Notes
• 120 kHz digital frequency counter, uses individual counter modules with individual neon lamps for display.

• Source of data
• -- Collector info (Sammler)

• Author
• Model page created by a member from A. See "Data change" for further contributors.

• Other Models

• Here you find 393 models, 361 with images and 138 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Hewlett-Packard, (HP); Palo Alto, CA