Error map from Stefan's long transmission,
http://abelian.org/vlf/tmp/160429a.gif
Each red line indicates a bit error.
I can use this recording to try the suggestion by Markus
to apply some sort of gain control using the adjacent
noise bands.
> What would hve been the shortest symbol length to
> get a decode on your side?
Probably 30 seconds would have worked too, but no less
unless you use a stronger code.
http://abelian.org/ebnaut/calc.php?sndb=25&snbws=10.3e-6&snmps=&code=8K19&sp=30&crc=16&nc=45&submit=Calculate
I've copied 7 of 7 messages from you successfully, that
means you're doing a good job of selecting the symbol
periods.
> why are only German stations transmitting on VLF these days?
No activity from the UK for a couple of years I think. Not sure
we can blame the need for a Notice of Variation, it isn't very
difficult to apply for. The T/A east to west is still waiting
to be done and the UK has a geographic advantage there. I would
have thought it the sort of thing a radio club could field a
team for.
--
Paul Nicholson
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