Hi Paul,
Thanks. That's an interesting result of our tests. I didn't expect such
a difference between day and night. Could it have to do with our
specific distance, or, could the observation be completely different in
a location beeing 200 km farer away?
In June, the signal was clearly shown on Renato Romeros grabber, now
there is no trace! Odd.
No more results on the last two attempts on 6470?
OK, let's try that. 15 chars on 6470 Hz in 12 hours, that sounds very
optimistic to me. I will prepare the system and announce:
f = 6470.00000 Hz
Start time: 13.10.2016 06:00:00 UTC
Symbol length: 20 s
Characters: 15
CRC 16
Coding 16K25A
Duration: 11h, 33m, 20s
Antenna current: 290 mA (ish)
73, Stefan
PS: Just to try something easy again i started a short transmission
that i can decode for myselfe (from the tree), to check the system is
running well:
f = 6470.00000 Hz
Start time: 12.10.2016 14:30:00 UTC
Symbol length: 40 s
Characters: 3
CRC 16
Coding 8K19A
Duration: 4h, 37m, 20s
Antenna current: 290 mA (ish)
Can you deocde the message as well? It is mainly in the time slot you
suggested and 3 characters in the same symbol length should work well
then.
Am 12.10.2016 11:40, schrieb Paul Nicholson:
Using the carrier on 6470.0025, I can see that the signal is
completely lost in the noise during the night.
Daytime S/N 06:00 to 18:00 UT is 21dB in 23uHz, which is
sufficient for, say, 15 chars with 20 second symbols using
16K25 for estimate Eb/N0 of +0.5 dB, duration 11:33:20.
Daytime signal averages about 0.05 fT or 15nV (about two
electrons on a 20pF antenna), nighttime looks similar as
far as I can tell through the noise.
We should try a daytime test.
--
Paul Nicholson
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