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Hi
Mike,
normally the frequency scale with GQD lock should
be very accurate, 12 mHz offset seems way too large.
Is the samplerate lock status showing green?
If yes, please temporarily retune the FFT center to an
accurately known CW signal, eg. one of the Russian Alpha lines
11904,761904, 12648,809524 or 14880,952380 Hz (multiples of 15625/21 Hz). If
that appears on the correct frequency, we'd probably have to conclude
that the peak was not Bob's carrier.
Good luck,
Markus (DF6NM)
Sent: Friday, March 07, 2014 11:55
AM
Subject: RE: LF: New OPERA OP/OPDS 2H
tonight on 27.945 Dial Freq...
I ran SpecLab last night using (almost) the
settings needed for 29kHz
OPDS, and had some pleasing results. The attached
pictures both show
a good trace on Bob's
frequency.:
capt07-rev.jpg
Shows the situation at 0900, with the green
line showing the night's
peak signal. Amplitude scale is 5dB/div. The
day/night noise
diference can clearly be
seen.
capt1403070931.jpg
This is a zoomed in view with the amplitude
scale at 2dB/div and the
SpecLab cursor moved so that the yellow line shows
the instantaneous
situation at 0400UTC. Bob's signal is some 5dB above noise
in a
119uHz FFT. Looking at the spectrogram itself, it is noticeable that
this signal is the sharpest despite the Op keying.
One surprising
thing is that, despite SpecLab being locked to GQD,
there is still a small
error (0.012Hz) in the displayed frequency. Is
this normal? I can easily
tweak the displayed frequency if needed.
I hope to set up OPDS
today.
Mike, G3XDV
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