[time-nuts] Vintage Frequency Measurement
alanh137 at gmail.com
Sun Feb 12 21:13:44 EST 2017
I have a General Radio Type CAG-60098-A Precision Wave Meter made for Navy
Department - Bureau of Ships according to the nameplate. According to
Wikipedia that would date it between 1940 (when bureau of ships was
created) and 1966 (when abolished). It has an inductor in sort of a
"hockey puck" labeled 16-50 kc that plugs into a socket on the front panel.
Inside is a very nicely made variable capacitor with a vernier drive. It
has been a while since I had it apart, but there is a diode in series with
the meter and not much else as I recall. The meter scale is 0-200
(microamp?) and the capacitor scale is 0-75 with no other marking. I have
no manual, but I assume there were other inductors for different frequency
ranges with a calibration chart to interpret the 0-75 reading. It must
have been made to test transmitters by tuning for peak reading on the meter
and determining the frequency from the dial reading.
a different Alan (KE7AXC)
On Sun, Feb 12, 2017 at 5:47 PM, Alan Melia <alan.melia at btinternet.com>
> Hi Dan yes that is 5e-6 about all an unstabilised (temp) AT could hold for
> any period. I guess there were no WWV or MSF signals around then. When a
> good source was available off-air it was possible to do better than that.
> In service it was probably "dont waste time trying to better the minimum
> requirement. The transmitter you are looking for wont be that accurate or
> In 1960s I saw several BC-221s in the racks at the Rugby LF and HF
> stations acting as standby frequency sources (VFO) for rapidly running up a
> transmitter on an unusual frequency (not a normal route) for which they did
> not have a crystal available.
> ----- Original Message ----- From: "Dan Rae" <danrae at verizon.net>
> To: "Discussion of precise time and frequency measurement" <
> time-nuts at febo.com>
> Sent: Sunday, February 12, 2017 11:11 PM
> Subject: Re: [time-nuts] Vintage Frequency Measurement
> To put BC-221 things in perspective, the 1 Mc/s reference crystal was
>> adjusted, according to the manual, to within 5 c/s...
>> Things have come a ways since!
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/m
>> and follow the instructions there.
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> and follow the instructions there.
More information about the time-nuts