Hi, Jim
I use exactly the same procedure with my Kachina and consistently measure
calibration errors in the order of two Hz or less. Amazing that radios in
these price classes could be so accurate. My Kachina has the High
Stability Crystal Oscillator option (crystal oscillator oven, etc.).
72/73, George
Fairview, TX 30 mi NE Dallas in Collin county
Amateur Radio W5YR, in the 54th year and it just keeps getting better!
R/C since 1964 - AMA 98452 RVing since 1972 Kachina #91900556
Jim FitzSimons wrote:
>
> Jan, I have been doing 0.1ppm for a long time. Long before digital
> readouts the ARRL had a frequency measurement test. It is a lot
> easier now. 0.1 ppm which is 1 Hz at 10 MHz. The fastest way to get
> a frequency measurement of 0.1 ppm at 2.5, 5, 10, 15, and 20 MHz
> WWV or WWVH is to use the sound card. Tune 1000 Hz high in LSB
> or 1000 Hz low in USB and look at the frequency with digipan or some
> other sound card FFT program. Select AFC so the program locks on the
> carrier. The frequency readout is good to 1Hz. I checked that with a
> frequency counter. You can use a lower frequency like 100 Hz offset
> and get even more resolution. As I write this I am measuring 1010.8 HZ
> using MixW FFT software on a Pegasus tuned to 10.001 MHz LSB. It
> measures 994.5 Hz tuned to 9.999 MHz USB. That is a 1ppm error
> on LSB and 0.5 ppm on USB. This with N4PY Pegasus sotware.
> The error is getting less as the Pegasus warms up.
> Regards, Jim FitzSimons W7ANF
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