Hi Paul, VLF,
Now there was the carrier during the whole night with 1.2 A . Do you
have some recommendations for me regarding the best time window for
that path?
I would like to pass one character over there without stacking. It
doesn't matter to run the same message again. Maybe it will decode in
that night on its own. But then it would certainly work when stacking
is used.
So if there is no great imrpovement to be expected from different
parameter settings, especially a longer transmission time, then i would
simply run the same message again as stated below. I will do so, except
you give me some convincing recommendations to start a new run.
Ah and it would be interesting to see a spectrum peak from the last
night, from Mikes RX and from yours! I know it is your world you are
operating in, so it is just a marginal effort to produce the peak i
would assume :-) And it is a clear contribution for the overall
activity on the band.
The 1.2 A carrier will then continue until 21:30 UTC and will go over
into the BPSK then...
73, Stefan
Am 07.12.2017 22:16, schrieb DK7FC:
45 minutes left before the message starts. I can change to CRC 12 but
08:08 UTC means that about the last 90 minutes are running in daylight
here.
Let me go to CRC 10, that's 9 hours and 36 minutes. And i'm starting 30
minutes earlier.
If it decodes it won't be the last message anyway. It is then just the
beginning! I would then want to pass my call over there for example,
i.e. 5+ nights of stacking...
So:
f = 17470.1000 Hz
Start time: 07.Dec.2017 21:30:00 UTC
Symbol period: 60 s
Characters: 1
CRC bits: 10
Coding 16K21A
Duration: 09:36 [hh:mm]
Antenna current: 1 A
73, Stefan
Am 07.12.2017 22:01, schrieb Paul Nicholson:
Stefan wrote:
> Today i'd like to try that first east to west VLF TA
> transmission. Let's try:
> f = 17470.1000 Hz
> Start time: 07.Dec.2017 22:00:00 UTC
> Symbol period: 60 s
> Characters: 1
> CRC bits: 6
> Coding 16K21A
That may decode in one attempt if lucky, but likely two
transmissions will be needed. If it does decode, then
the chance of it being the correct decode from random
noise is 0.02 %.
Can you run until 08:08 UT with CRC 12 and the other
settings the same? A gain of 0.74 dB which will make
a good difference. And if it decodes, the chance of
a random correct decode is only 0.0004 %.
I hope the weather doesn't spoil the transmission, but
if you keep trying, you are sure to succeed.
--
Paul Nicholson
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