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720-A: Difference between revisions
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(Created page with "Type '''720-A Heterodyne Frequency Meter '''. ==Specifications== ==Links== ==Photos== <gallery> </gallery> Category:Frequency Standards and Meters") |
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{{GR Product | |||
|model=720-A | |||
|class=frequency standards and meters | |||
|summary=frequency meter | |||
|image=GR 720-A Close-up.jpg | |||
|caption=General Radio 720-A Frequency Meter | |||
|series= | |||
|introduced=1945 | |||
|discontinued=1959 | |||
|designers= | |||
|manuals= | |||
* [[Media:720-A Frequency Meter.pdf|General Radio 720-A Manual]] | |||
{{Catalog History}} | |||
}} | |||
The '''General Radio 720-A Frequency Meter''' was introduced in {{Catalog K4}} and remained available through {{Catalog P}}. | |||
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. 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== | ==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== | ==Links== | ||
* [[Media:GR Exp 720-A 07_1945.pdf|Experimenter describing Type 720-A July 1945]] | |||
* [[Media:Grid Bias Cells.jpg|Bias Cell Data]] | |||
* [[Media:1N Series Microwave Diode Data Sheet.pdf|1N21B Microwave Diode Data]] | |||
==Photos== | ==Photos== | ||
<gallery> | <gallery> | ||
GR 720-A Front.jpg | |||
GR 720-A Case Closed.jpg | |||
GR 720-A Case Cover.jpg | |||
GR 720-A Front A.jpg | |||
GR 720-A Instructions.jpg | |||
GR 720-A Open Case.jpg | |||
GR 720-A Power Supply.jpg | |||
GR 720-A Left Side.jpg | |||
GR 720-A Rear Inside.jpg | |||
GR 720-A Right Side.jpg | |||
GR 720-A Top A.jpg | |||
GR 720-A Top.jpg | |||
</gallery> | </gallery> | ||
[[Category:Frequency Standards and Meters]] | [[Category:Frequency Standards and Meters]] | ||