ARRL Frequency Measuring Test, April 2016

The results of the recent ARRL Frequency Measurement Test (April 7, 2016) were published early this morning. Once again I managed to measure the frequency of K5CM with a pretty good accuracy of -0.44 Hz. 

I used a very basic setup, which consists only of my Icom IC-706 MkII tranceiver with a dipole antenna (currently near the ground, pending installation of a 4 m mast), a PC with a standard soundcard and the GB3RAL software, normally used to receive the 5290 kHz beacons.

The Icom radio has an option to display frequency with a precision of 1 Hz, instead of the 10 Hz display of other radios.

My metodology is to calibrate the whole system against stations CHU (7850 kHz) and  RWM (4996 kHz), and a GPS-referenced source on 10000 kHz. I produce a first degree calibration equation, which I use to correct the display of the radio with the actual FMT signal.

This time I concentrated on the 40 m CW transmission of K5CM. The 20 m path was closed and 80 m is too noisy at my location. On 40 m, near 7055 kHz, I measured a carrier frequency of 7055773.15 Hz instead of the correct value of 7055773.59 Hz (error -0.44 Hz), which I believe is a good achievement with such a basic setup.

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