Hi Wolf,
Thank you.
And what about WOLF included within SpecLab? This would help a lot,
regarding the drift and offset compensation, especially for the receive
stations. Do you think it could be implemented into the digimode
terminal?
73, Stefan
Am 02.02.2012 19:13, schrieb wolf_dl4yhf:
Hi Stefan,
about your question:
Then i've done several tests using different frequency tolerance values
(above: t = 0.3 Hz). After calibrating the soundcard by using the shown
offset, the offset was 0, consequencial ;-) But even if a tolerance of
0.002 Hz was choosen, it still took about the same time to get
the first decode. Any comments?
The reason is, the WOLF decoder processes an entire band
simultaneously. It's like having a bunch of receivers working in
parallel, each of them looking on its own frequency. This is the reason
why the CPU load from the decoder increases dramatically when using a
larger frequency tolerance.
Right now i feeld that i am missing a spectrogram which i can
show here. Just text! Odd.
One possibility to have a spectrogram-like display would be to square
the 'downconverted' (baseband) WOLF signal. The spectrum of the squared
signal should show distinct lines as already mentioned by Markus.
I just wasn't aware of this when I wrote the graphic user interface for
Stewart's WOLF decoder.
In the normal spectrum, you will indeed hardly notice the WOLF signal,
which renders the display quite useless as the indicator for the
'presence' of a signal. The trace gets invisible in the spectrogram
long before it drops below the level for successful decoding.
All the best and good luck with the VLF tests, it's very interesting.
Especially when considering the possibilities with GPS-based
synchronisation (which, of course, does *not* exist in the present
implementations of the decoder).
Wolf DL4YHF .
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