722-D

The General Radio 722-D Precision Capacitor was introduced in Catalog J (1936) and remained available through Catalog P (1959).

The Type 722-D is a laboratory quality dual section precision variable capacitor. Its direct reading on both sections read from a drum mounted on the roto shaft. The rotor is mounted on ball bearings in a aluminum casting driven by a precision worm drive. The rotor is electrically attached to the frame with silver overlay contacts. The two stators are brought out to separate terminals on the panel with the shared rotor terminal. The rotor terminal is a the same potential as the panel and copper lined walnut case. A correction chart is mounted on the panel for that particular capacitor. The capacitor is supplied with fitted wooden carrying case.

Specifications

• Capacitance Range 25 to 100 pF and 100 to 1100 pF
• Dial Accuracy: High Range ±1 pF ±0.1%; Low Range ±0.2 pF ±0.1%
• Maximum Voltage: 1000 V peak

Links

• Experimenter describing Types 722 February 1937
• Experimenter describing Types 722 January 1938
• Experimenter describing Types 722 October 1938

Photos

• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• Carrying Case

  Carrying Case

• Carrying Case

  Carrying Case