Hi Paul,
Thanks for the most ineresting experiments, even if the result is
negative sometimes.
Well it's not as easy as expected it seems. I did expect that the decode
will be no problem with the added signals. Local experiments are not
useful since my distance to the tree grabber is just 3.5 km. Anyway it
is a real experiment with some path, so maybe i will do some QRP tests
anyway.
Today the WX wasn't really good here and i've been motivated to continue
to work on the large ULF coil. A very big step was done today,
variometer is completed and i calculated that i need a 6th stack which
must have 8 layers. Now 7 of them are completed! I will finish the
winding today! That work took several month, 6 kg of cu wire is used,
about 150€ just for the wire.
More later...
73, Stefan
Am 06.11.2016 21:50, schrieb Paul Nicholson:
Stefan wrote:
> f = 6470.00000 Hz
> Start time: 03.11.2016 06:00:00 UTC
> Symbol length: 30 s
> Characters: 11
> CRC 16
> Coding 16K25A
and
> A second transmission is running now [5th Nov]
> Same message, symbol length, phase orientation
> and start time...
No decode of either message.
I added the two days coherently and that also failed to
decode. I tested the processing with simulated signals
and that gave the expected 3dB gain.
Looked at the cross correlation of the two days but can
see nothing. The simulated signals at about Eb/N0 0.0dB
are visible on a cross correlation.
This will only work if the received phase doesn't change
much from one day to another. We may need some luck, some
stable weather and ionosphere.
To keep the office warm, the computer is trying some
range of phase shifts between the two days.
--
Paul Nicholson
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