Amazing; congratulations to Dex on T/A message length record and excellent
signal, and Paul and all others on great set of receiver decodes.
Among the coverage spans, (Hawley, TX, upstream, all overland)/(Warsaw,
downstream including overland) is also inspiring.
Peace and happiness to all today and in the new year,
Jim AA5BW
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Paul Nicholson
Sent: Monday, December 25, 2017 5:52 AM
To: [email protected]
Subject: Re: VLF: A message from W4DEX
> another big step since New Year 2015.
We can always count on Dex to try to push the limits out further.
Last night the noise was low, so low that the best S/N was bearing 290. Dex on
284.6. Usually the S/N peaks up by aiming off at 310 to 330.
It was also the first time I used the new antenna calibrations to mix the
signal for a decode.
We used 8269 to avoid any overlap with VO1NA.
Given those conditions, we could have tried 42 chars, 16K25A CRC16 with 7
second symbols 23:00 to 08:05:04, for Eb/N0 -0.15.
Correlations from on-line receivers (a loss of perhaps 1 to 2dB due to vorbis
encoding):
Bielefeld 6918 km, Eb/N0 -12.3 dB;
Cumiana 7173 km, Eb/N0 -10.0 dB;
Warsaw 7681 km, Eb/N0 -19.7 dB;
Forest VA 254 km, Eb/N0 -1.2 dB *Decoded* rank 0;
Hawley TX 1816 km, Eb/N0 -7.7 dB;
The low Eb/N0 at Forest is surprising. Something is wrong, should be a huge
signal. In 2015 Dex's EbNaut was even visible on a spectrogram at Forest.
What do normal people do on Christmas day morning? I was out at the H rx site
with a spectrum analyser looking at the amplitude of some MF signals (909kHz
5mV RMS on the open circuit loop).
Meanwhile, I'm running low on celebratory cigars!
--
Paul Nicholson
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