Message-ID: <5685625B.5080204@abelian.org>
Date: Thu, 31 Dec 2015 17:14:03 +0000
From: Paul Nicholson <vlf0403@abelian.org>
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Subject: Re: LF: 8270Hz
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Strong carrier again Uwe,

  http://abelian.org/vlf/fbins.shtml#p=1451559600&b=080&s=sp

 > At the beginning a message:

 > Start 2015-12-29 23:00:00
 > Period 10
 > Length 2
 > Duration 01:01:20:00
 > Bits 368

I could not decode anything.   The following carrier
measured 18.4 dB in one hour integration and the signal
calculator

 
http://abelian.org/ebnaut/calc.php?sndb=18.4&snbws=&snmps=3600&code=8K19&sp=10&crc=16&nc=2

says that should give Eb/N0 of about 8dB.   When I run the
carrier into the decoder it comes out well

  vtraw -oa dj8wx.151229b.vt |
     ebnaut -d -p8K19A -r240 -S10 -PS -N2 -v -c1

  initial reference phase 76.9 amplitude 2.991e-03
  prep [  0    0    0    0    0]
  found rank 0 ber 2.4457e-01 Eb/N0 8.9 M -1.063431501e-01 [**]
       ps [  0    0    0    0    0]
  carrier phase: 7.5
  carrier Eb/N0: 7.8
  carrier S/N: 18.39 dB in 271.7 uHz
  elapsed 5

which agrees with the signal calculator.

With that strong signal, the message should have been an easy decode.

So, something is wrong with the modulation or bit clock.
If you tell me the message, I can analyse the signal.

I have been checking for your long carriers in very narrow bandwidth
at Forest VA (distance 6667.7 km) but so far no sign of anything.


--
Paul Nicholson
--