AW: Re: AW: LF: 8270 Hz traces again! AK

[uwe-jannsen@kabelmail.de]

hope the transmission can stay 24 hours a day on the air soon.
so your analysis may show less phase destructions at night hours.
Uwe/dj8wx

 

Von: Paul Nicholson <vlf0403@abelian.org>
Gesendet: 01.12.2015 23:27
An: <rsgb_lf_group@blacksheep.org>
Betreff: Re: AW: LF: 8270 Hz traces again! AK

 

Uwe wrote:

> transmission CL because of heavy rain

Got a good carrier from you

http://abelian.org/vlf/fbins.shtml#p=1448996400&b=090&s=sp

and this decoded easily in EbNaut using 10 second symbols,
eg 8K19A 2 characters,

found rank 7: ** ps [ 2 30 30 30 30]
re-encode 140/368 ber 3.80e-01 Es/N0=-13.3 Eb/N0=1.6

Carrier decodes as a series of '*' characters which is handy
for testing. Using the carrier I can try a range of message
lengths and symbol periods.

Using about an hour of carrier from 17:00 I got

8K19A, 8 seconds, 3 chars: Eb/N0=-0.2
16K21A, 4 seconds, 3 chars: Eb/N0=1.0
8K23A, 7 seconds, 4 chars: no decode

I grabbed 3 hours of carrier, 15:00 to 18:00 and played around
with that but couldn't get a decode from it. It's a bad time
of day due to the terminator passage, the phase goes all over
the place so I'm not too surprised.

Tested the carrier 15:00 to 16:00 and got

8K23A, 7 seconds, 4 chars: -0.8 dB (BER 38.9% rank 679)
16K21A, 3.4 seconds, 5 chars: -0.7 dB (BER 41.4% rank 3200)

I couldn't get anything from the 90 minutes 15:00 to 16:30.

--
Paul Nicholson
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