[BC] Frequency measurement...

[Gary Peterson]

" I had a slightly different method for measuring frequency with an
IFR-1000S. Its frequency error meter didn't have the resolution to see
as close as needed for AM, so I had to figure out a different way. The
easiest way I found (note this sounds far more complicated than it is)
was to dial in the frequency 1000 Hz below the proper carrier frequency
that I was to measure then turn on the BFO. This would give you a beat
note of 1000 Hz +/- the error frequency. I would in turn beat that
resulting tone against the precision audio oscillator. then simply read
the frequency of the audio oscillator when I got the zero beat and
subtract 1000.
Alan Alsobrook "

Our amateur radio club (W?BLK) participated in the last ARRL frequency
measuring test last November 15.  First, we had a class on measurement
techniques for various modes.  Then, we did the real thing for the FMT.  The
signal on 160 meters was not readable.  In spite of rather poor propagation
that night, we were able to measure the 80 and 40 meter signals.

Our methodology consisted of setting the digital display on a Yaesu
FT-1000MP to read 1 kHz above and below WWV on both 5 and 10 MHz and
directly measuring the frequency of the beat note (~ 1000 Hz) with a good
frequency counter (Sencore FC-51). (The 10 MHz time base in the counter was
previously zero-beat with WWV) (The input to the counter was attached to the
speaker leads on the transceiver)  This data was recorded.  During the ~
3.587 and ~7.038 MHz transmissions, the transceiver was adjusted for an
approximate 1000 Hz beat note and the transceiver's digital dial readings
and frequency counter readings were logged.  From this data, it was possible
to back calculate the frequency of the signals we were trying to measure.

The "umpire" said our 80 m submitted measurement was -0.5 Hz in error (-0.14
ppm) and our 40 m submitted measurement was +0.6 Hz in error (+0.09 ppm).

Not too shabby for amateurs, using non-laboratory equipment.

Gary, K?CX
CE KFXS, KOUT, KKMK, KRCS, KKLS & KBHB
Rapid City & Sturgis, SD