RR Markus, thanks.
Yes, 1.65 kHz is on the list.
BTW the message has been decoded from the data of IK1QFK, with > 14
dB SNR. But more later.
73, Stefan
Am 15.04.2019 22:02, schrieb Markus Vester:
Hi
Stefan,
>
Do you have an idea why the E-W cardioid result is worse than from the
E field alone?
Looking
at https://vlf.u01.de/VLFgrabber/vlf9.jpg we
find that the noise grew much more on the earth loop (top) than on the
E-field (bottom). One reason may be that our earth antennas pick up
more 50 Hz harmonics - these won't interfere with your QRG directly but
may raise the noise blanker threshold and make spherics blanking less
effective. We could also speculate about spherics with steep incidence
angle, albeit you were more or less in the middle between 1st and 2nd
vertical tweek resonances (1.65 and 3.3 kHz). Anyway the SNR ratio
between H to E seems to be similar to your receivers.
Of
course skywave components may also have a direct effect on your signal
but I don't know whether that would have been positive or negative, or
in which way to extrapolate downwards. I'm very curious what would come
out of a 1.65 kHz transmission during a quiet night.
> Which carrier S/N do you
get from the E field?
Decoder
output "carrier S/N 24.31 dB in 128.6
uHz" - should be related to carrier Eb/N0 by adding 10
log (ncharacters * 5.7).
Best
73,
Markus
-----Ursprüngliche
Mitteilung-----
Von:
DK7FC <[email protected]>
An:
rsgb_lf_group <[email protected]>
Verschickt:
Mo, 15. Apr. 2019 10:32
Betreff:
Re: ULF: Ground loop night transmission 3.0
Hello Markus, ULF,
Very well. Thanks for your decodes and for sharing the night :-)
Do you have an idea why the E-W cardioid result is worse than from the
E field alone?
Which carrier S/N do you get from the E field? I'm getting carrier S/N:
40.62 dB in 128.6 uHz, 1.71 dB in 1Hz
The difference of our carrier Eb/N0 is 16.3 dB. But as Paul mentioned,
camparing carrier S/N may be more accurate in that spectrum range.
It could be interesting to compare the SNR difference between our
locations over some frequencies. If that value is reasonable constant,
in the far field, then we could estimate what we can expect at 970 Hz...
My results from all 3 antennas are still looking good at that frequency:
E field: carrier S/N: 40.62 dB in 128.6 uHz
N-S loop: carrier S/N: 28.38 dB in 128.6 uHz
E-W loop: carrier S/N: 30.47 dB in 128.6 uHz
73, Stefan
Am 15.04.2019 01:33, schrieb Markus Vester:
Hi Stefan,
DL0AO H-field (E-W): Eb/N0 = 2.5 dB(car), 0.7 dB(sym),
DL0AO E-Field: Eb/N0 = 12.0 dB(car), 10.9 dB (sym).
Our file ended a couple of minutes early with the last
12 symbols missing, causing a slightly high symbol error reading.
73 and good night,
Markus (DF6NM)
-----Ursprüngliche
Mitteilung-----
Von:
DK7FC
<[email protected]>
An:
rsgb_lf_group
<[email protected]>;
Renato Romero
<[email protected]>
Verschickt:
So, 14. Apr. 2019 23:13
Betreff:
Re: ULF: Ground loop night
transmission 3.0
Hello ULF friends,
Now i'm sitting in the car again in the deep forest. It is silent
(outside!) and the sky is clear. The TX and EbNaut message is now
running:
f = 2470.1 Hz
Start time: 14.APR.2019 21:00:00.3 UTC
Symbol period: 9 s
Characters: 3
CRC bits: 16
Coding 16K21A
Antenna current: 2.5 A
Duration: 02:09:36 [hh:mm:ss]
TX power at the beginning of the transmission is 492 W this
time.
73, Stefan
Am 14.04.2019 14:41, schrieb DK7FC:
Hello Dreamers,
Today it feels right again, i'd like to have another exciting
adventure...
After the recent successes at 2970 Hz, maybe it is possible to get
something through at 2470 Hz? That's the 121 km band. So far, thge
distance record at this frequency is over to DL4YHF, QRB ~ 313 km.
I'd like to try the following:
f = 2470.1 Hz
Start time: 14.APR.2019 ab:cd:00.3 UTC
Symbol period: 9 s
Characters: 3
CRC bits: 16
Coding 16K21A
Antenna current: 2.e A
Duration: 02:09:36 [hh:mm:ss]
More details regarding start time and antenna current will follow after
the transmission has started.
Reports requested / welcome :-)
73, Stefan
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