Jim's frequency is 135923.99 Hz and has remained absolutely stable to within
the 0.01Hz readout resolution since measurement started at 1945z.
Occasionally I read it as ~.98 so the actual freq may be nearer ~.988 (ish)
Laurie, unfortunately you are drifting somewhat. I've seen at least 0.15Hz
shift.
At 1945 it was 135922.34 and drifted to ~922.23 at 2020 where it remained
until 2100z. Then you jumped to ~922.38, then ~2.33 at 2113z and drifted
back to ~922.25 by 2220z. Then a similar kink later at 2240z after a break
in transmission. The excursions usually seem to be around 0.09 Hz
Measurement equipment is a RA1792 with its external reference input driven
by a Caesium standard (with the Cs tube turned on for the first time in
nearly a year) so RF accuracy is 'perfect' The sampling clock in the
EVM56002 is the only frequency error and this is better than 1ppm so for a
1kHz tone max error is 0.001Hz. A great pity I can only read the frequency
off the display to two decimal places !
Attached is AQCBMU.GIF (8KB size) showing 90 minutes of both of your signals
in a 2.5Hz wide plot and the drift pattern on Laurie's signal. There is
about 7dB difference in signal strength between both transmissions which
considering the distances (Laurie is nearer and the stronger) means very
similar ERPs. Jims fast CW ident keying sidebands are very clear
Andy G4JNT
|
