720-A

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General Radio 720-A
Frequency Meter
General Radio 720-A Frequency Meter

Available from 1945 to 1959

Manuals
Catalog History
 Document Year Page
Catalog K4 1945 144
Catalog L 1948 180
Catalog M 1951 212
Catalog N 1954 220
Catalog O 1956 85
Catalog P 1959 87
(All manuals in PDF format unless noted otherwise)

The General Radio 720-A Frequency Meter was introduced in Catalog K4 (1945) and remained available through Catalog P (1959).

The Type 720-A is a heterodyne type frequency meter using a calibrated oscillator from 100 to 200 MHz. Using harmonics frequency measurement from 10 MHz to 3 GHz are possible. Using a built in antenna to couple the unknown a zero beat can be obtained and monitored. The beat note is displayed on a panel meter and heard with an internal speaker. The 720-A can be powered by Burgess 6TA60 battery or the Type 1261-A power supply. "Bias Cells" provide grid bias potentials B1 and B2. See "Bias Cell" information below.

Specifications

  • Frequency Range: Fundamental frequcncy range is from 100 to 200 MHz. harmonics 10 to 3000 MHz
  • Calibration: The main dial is calibrated in frequency, each division corresponding to 1 MHz
  • Accuracy: The overall accuracy of measurement is 0.1 %

Links

Photos