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Bob, Dex,
In the morning, the carrier from
Dex on 74323 became also clearly visible in the 0.95 mHz spectrogram.
So I tried to rescan the recorded files with a lower detection threshold just to
see how close it was (a sort of deep deep search ;-).
Using opds.ini
parameters
thresholddbcor=11.5
'minimum correlation peak height; default 15 dB,
ns1=2 'less
smoothing during carrier detection, more sensitive for stable
signals; default 5 bins,
and pruning out false detections on other frequencies,
I ended up with 2 more spots for Bob and 3 for Dex:
opds16: date time
call
distance frequency bandwidth
snr correlation
2014-02-09 06:56:21 WG4XRS 6448km
74321.301Hz 5mHz -45.8dBOp 100% 14.3dB
2014-02-09 06:23:13
WG4XRS 6448km 74321.301Hz 4mHz -47.7dBOp 86%
15.9dB
2014-02-09 06:17:18 WG5XRS 7214km 74323.000Hz
4mHz -48.0dBOp 95% 12.0dB
2014-02-09 06:06:40 WG4XRS 6448km
74321.301Hz 4mHz -46.2dBOp 99% 17.2dB
2014-02-09 06:00:54
WG5XRS 7214km 74323.000Hz 3mHz -49.4dBOp 100%
11.9dB
2014-02-09 05:50:06 WG4XRS 6448km 74321.301Hz
5mHz -46.3dBOp 98% 14.8dB
2014-02-09 05:44:31 WG5XRS 7214km
74323.001Hz 3mHz -50.6dBOp 94% 11.9dB
2014-02-09 05:33:33
WG4XRS 6448km 74321.301Hz 4mHz -48.6dBOp 88%
15.1dB
2014-02-09 05:16:59 WG4XRS 6448km 74321.301Hz
5mHz -46.5dBOp 97% 15.1dB
2014-02-09 03:21:06 WG4XRS 6448km
74321.301Hz 4mHz -49.3dBOp 100% 14.3dB
2014-02-09 02:31:29
WG4XRS 6448km 74321.300Hz 3mHz -50.5dBOp 100%
12.6dB
In past sessions,
there were still weak DCF77 artifacts exactly on whole Hz frequencies. Even
though these were not obvious in the higher noise last night, Dex' carrier might
still have been slightly impeded. This could be cured by a small offset eg.
moving 0.1 Hz down.
Best 73,
Markus (DF6NM)
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