Thanks Paul for the summary.
Well, 8 days already and it gets worse. I think the phase changes are
not from my side, so it must be the path.
I think i will give up now with this 3 character message. But even a
failed attempt gives us a set of data showing the difficulties and
phase variations.
On the other side, a single character message is to short to let it be
as it is. So i'm trying a new message with just 2 characters before
going down to 5170 Hz.
If possible, i daily feedback is apprechated.
f = 17470.1000 Hz
Start time: 18.Dec.2017 21:30:00 UTC
Symbol period: 45 s
Characters: 2
CRC bits: 14
Coding 16K21A
Duration: 09:12 [hh:mm]
Antenna current: 1.2 A
73, Stefan
Am 18.12.2017 18:56, schrieb Paul Nicholson:
Results from eight overnight transmissions of the
3 character message:
2017-12-10/11 Eb/N0 = -13.1 dB
2017-12-11/12 Eb/N0 = -6.3 dB, phase 125.3
2017-12-12/13 Eb/N0 = -6.8 dB, phase 143.2
2017-12-13/14 Eb/N0 = -19.6 dB (stopped 03:40 by safety limit)
2017-12-14/15 Eb/N0 = -6.0 dB, phase 68.8
2017-12-15/16 Eb/N0 = -11.0 dB
2017-12-16/17 Eb/N0 = -14.6 dB
2017-12-17/18 Eb/N0 = -9.9 dB, phase 37.0 (stopped 04:19 by snow)
Stacking
11/12 + 12/13 gives Eb/N0 = -3.6 dB.
11/12 + 12/13 + 14/15 gives Eb/N0 = -3.0 dB.
11/12 + 12/13 + 14/15 + 15/16 gives Eb/N0 = -2.5 dB.
11/12 + 12/13 + 14/15 + 17/18 gives Eb/N0 = -3.4 dB.
There's some phase changing going on here which is making
stacking not so effective.
--
Paul Nicholson
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