Hi Paul, VLF,
I'm just playing a bit with SpecLab, listening to Sferics, playing with
the noise blanker and so on.
The QRN is extreme, day and night. I don't see many chances that my 68
hour transmission will lead to a successful decode. Anyway i'll
continue to run it. If you can't decode it, i will tell you the message
so you can see how many dBs were missed. And it would be interesting to
know about the signal stability because i have done some improvements
on the phase locking arrangement (hardware).
It is running since 41 hours now and the transmitter is on the air
since nearly 4 days without an interruption :-)
I'm really looking forward to 5170 Hz but first we have to manage these
20 characters on 6470 ;-)
So, just these few thoughts for the moment.
73, Stefan
Am 21.05.2016 17:52, schrieb DK7FC:
Hi Paul,
Thanks! The message is correct. Our longest message so far on 6470 Hz
:-)
The WX forecast is no ideal for the next days: Rain! My transductor
variometer is still not automatised and its tuning range is a bit
small. So probably it is not possible to hold the antenna current
during rain. I also saw that the losses are higher when it's wet, makes
a difference of about 10%, i.e. -0.9 dB.
With a stable antenna current of 250...260 mA and low QRN it could be
possible to make the 20 character message with 100s symbols, into a
day-night-day period. However this will be hard in the coming days.
So i better prepare for 200s now:
f = 6470.00000 Hz
Start time: 22.05.2016 04:00:02 UTC
Symbol length: 200 s
Characters: 20
CRC 16
Coding 8K19A
Duration: 2d, 20h, 26m, 40s
Antenna current: 200...260 mA (Rain!)
73, Stefan
Am 21.05.2016 04:15, schrieb Paul Nicholson:
Stefan
wrote:
> f = 6470.00000 Hz
> Start time: 20.05.2016 00:30:02 UTC
> Symbol length: 100 s
> Characters: 10
> CRC 16
> Coding 8K19A
Copied 'THAT WORKS'
Eb/N0 = +2.7 dB, constant reference phase
Carrier: 19.25 dB in 13.3 uHz
Error map: http://abelian.org/vlf/tmp/160520a.gif
--
Paul Nicholson
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