Thank-you again, Paul. Tonight an unmodulated carrier with better phase
stability (hopefully).
73
Joe VO1NA
On Thu, 9 Nov 2017, Paul Nicholson wrote:
cat msg7 |
ebnaut -et -N8 -k20 -p16K21A |
sudo ebkey -S21 -m rp,gpio=23 -T '20171106 2200'
Decoded 'EINSTEIN' from the overnight 8th/9th transmission.
Eb/N0 = -0.5 dB, constant reference phase, BER 41.1 %
Symbol error map http://abelian.org/vlf/tmp/171109a.gif
Night Eb/N0 Phase S/N
6/7th -20.0 dB < -48 dB in 1Hz
7/8th -3.7 dB 97.6 -31.79 dB in 1Hz (E+H)
8/9th -0.5 dB 128.8 -28.63 dB in 1Hz (E+H)
8/9th -3.2 dB 131.1 H-field only
8/9th -2.3 dB 126.7 E-field only
Nothing at all from the 1st night and clearly something
broke during the 2nd night.
After a full phase search I got a slight improvement to -0.4 dB
with phase pattern -150,-150,180,180, which means the signal
phase is lagging a little (on average) after about 02:00.
This decode is about at the limit for the transmitter power and
message duration. Looking at the error map, we might be able to
use a longer message but will probably only manage 9 chars max.
--
Paul Nicholson
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