C2 Frequency Indicator
Frequency Indicator type C2 is a direct reading, heterodyne type frequency measuring instrument, the accuracy of which is based on a built-in secondary standard - ie a Calibrator.The instrument is intended for use in aircraft, fixed ground and mobile stations under wide ranges at atmospheric conditions.
RCAF Stores No. 10D/3789
RCN Stores No. 3K/2014
Frequency Range: Five 1 MHz ranges covering 5 to 10 MHz. By the use of harmonics, the overall frequency range may be extended depending on the strength of the signal being measured.
Primary Power: Battery
Manual Ref: C.A.P. 63-l52
Comment: The SPARC Museum has a C2 frequency meter in their collection. This tag was found inside the C2 manual. . It looks like the government had C2 frequency meters left over from wartime contracts and were selling them off cheaply in 1947. The "Mr. Hodgson" named on the receipt was Ronald Hodgson, VE7BY.
To eliminate errors due to temperature and/or battery voltage change, it is necessary to compensate the heterodyne oscillator. This correction, which should be made prior to each measurement, is made by an adjustment ot the vernier dial scale with respect to its index line. No calculations are involved. Later designs ( S/N 788 and above) have a moveable index line adjusted by a thumb wheel.
When mounted in aircraft or ground vehicles, the unit is suspended on a shock absorber mounting.
For portable use, or in fixed station location, the shock absorber is not used.
|C2 S/N 1888 Frequency Meter. (Photo by Bruce MacMillan)|
|C2 S/N 1163 in shipping/carrying case. (Photo via E-bay)|
|This example illustrates the RCN's designation for the C2 frequency meter. (Photo by Charles Bacon VE7CRB)|
|Here is one of the early (prior to S/N 788) C2 frequency meters which lacks the "vernier index" frequency adjustment control. (Ebay photo) .|
Contributors and Credits:
1) Bruce MacMillan <bruce_macmillan(at)telus.net>
2) Charles Bacon VE7CRB <cb1997(at)7crb.com>
3 Tom Brent <navyradiocom(a)gmail.com>