Hi Paul, Markus,
thanks for the good work. It is interesting to see the combioned SNR
building up in these very noisy days.
On a quiet winter day we could decode the message in a single day maybe.
If the message would be unknown, could you still fin out that it is
better to leave the 24th out, just by checking the noise background
relative to the other days or the days where i sent the carrier?
Also thanks Markus for trying to get further results from stacking the
daily transmissions.
It would be interesting to analyse the different VLF and ULF bands to
see where the daily diurnal phase is most constant. That would limit
the number of stackable days to get better results. We never tried to
stack more than 9 days (that was on 2970 Hz) if i remember correctly.
One day we may need to do that on 970 Hz! I'm working on the
next QRO step on that 309 km band! I think i will need +12 dB to get
good results at 50 km distance. To reach DL0AO would maybe require
another 12 dB, which will not be possible. All in all i may rise the
power by 15 dB relative to now. Then stacking of 4 days would help to
see something at DL0AO however! Most exciting!
Hmmm, now, when thinking about that: would it maybe work to stack 16
days to see a trace at DL0 AO, now with the 5 kV (3 nW ERP)? That's
just about 2 weeks! :-) I got 15 dB in 47 uHz in 27.2 km distance with
an E field antenna, also during noisy days.
Markus, what do you think?
Maybe, can i ask for a 424 uHz spectrogram from W and EW? That would
give an impression on the diurnal noise and daily variations.
I could set up my modified mains transformer to run 15 mA antenna
current at 970.005 Hz for several weeks! Maybe we will see the
impossible, beyond our garden fences!
73, Stefan
Am 27.08.2017 22:13, schrieb Paul Nicholson:
Daily Eb/N0:
23rd -6.2 dB
24th -16.8 dB
25th -9.2 dB
26th -10.3 dB
27th -9.8 dB
Combined is -5dB but if I leave out 24th we get -3.7 dB.
No other combination improves on that.
I tried a 'known phase' decode with the appropriate optimum
list, I took the reference phase from your 2 daytime carriers.
But not there yet. One good day would do it. The conditions
on the first day of carrier were the best we've seen, it has
been noisy since then.
--
Paul Nicholson
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