LF,
Unfortunately i obviously forgot to change to symbol length from 4
seconds to 8 seconds, so my message was transmitted in half the time
and then followed by a carrier taking about 15 minutes :-/
That costs 3 dB Eb/N0 for the message and will lower the phase plot
quality. And i occupied twice the bandwidth. Anyway the message can be
decoded. And the carrier can be treated as a second message of
identical parameters but the message will be '****'.
A lot to play with, for the RX stns.
Tonite i'll QSY to ELF (the real ELF, ITU band 1) for the first time
here. The tree will come back today and there will be 1 or 2 VLF/ULF
experiments this weekend.
73, Stefan
Am 16.01.2019 14:15, schrieb DK7FC:
Hello Rob and Jay,
Many thanks for the reports and all the details. Jay, did you miss the
22 UTC transmission or did it not decode?
Interesting to see the phase plots. It is expected that the phase is
less stable when the band opens. In the last transmission, the Eb/N0 is
not high enough to see the phase pattern.
I wonder if the traces become more evident if 4K19 is used.
What happens when a solar event happens during the transmission time?
Does it change the phase or just the D layer attenuation?
Maybe we can repeat the experiment, using 4K19A. Of course a carrier
could be used too, but i like to 'play' with EbNaut.
So, tonite:
f = 137.545 kHz
Start time: 16.JAN.2019 22:00:00.3 UTC
Symbol period: 8 s
Characters: 4
CRC bits: 16
Coding 4K19A
Antenna current: 4 A
Duration: 30:56 [mm:ss]
73, Stefan
Am 16.01.2019 12:29, schrieb Rob Renoud:
Stefan,
Late start but 7 successful decodes. Have not gotten to phase
plots yet...
| UTC |
Rank |
C
Eb/N0 |
Eb/N0 |
MSG |
Ref
Phase |
| 0100 |
0 |
5.6 |
1.6 |
2019 |
0,-30,0 30 |
| 0200 |
0 |
6.9 |
0.4 |
2019 |
60,30 30 0 |
| 0300 |
0 |
9.9 |
5.8 |
2019 |
90,60,60,0 |
| 0400 |
0 |
11.2 |
8.8 |
2019 |
180,180,150,150 |
| 0500 |
0 |
6.3 |
2.7 |
2019 |
0,-30,-30,-60 |
73,
Rob – K3RWR
Sent: Tuesday, January 15, 2019 9:33 PM
Subject: Re: LF: Re: EbNaut tonite
LF,
Today, the messages will be transmitted as announced, starting 22 UTC
73, Stefan
Am 14.01.2019 22:16, schrieb DK7FC:
PS:
Repeatinh hourly, until including 6 UTC.
Am 14.01.2019 22:13, schrieb DK7FC:
Hi
LF,
Just a short EbNaut message tonite. I'm interested to see the phase
changes on a long path. Markus's showrawsyms does a good job there, as
long as 8K19A is used. A shorter message should also help to build up a
clear trace.
So let's try an unusual short message:
f = 137.545 kHz
Start time: 14.JAN.2019 22:00:00.3 UTC
Symbol period: 4 s
Characters: 4
CRC bits: 16
Coding 8K19A
Antenna current: 4 A
Duration: 30:56 [mm:ss]
Reports, including phase plots, welcome :-)
73, Stefan
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