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Stefan
Looking forward to 17.47 kHz. Remember, some of my
best receptions of SAQ 17.2 kHz were during their summer (in June IIRC)
transmissions!
Jay W1VD WD2XNS WE2XGR/2
----- Original Message -----
Sent: Monday, February 26, 2018 9:34
AM
Subject: Re: LF: VLF DK7FC > W1VD 8.27
kHz EbNaut more success!
Hi Jim,
Yes but the messages from VO1NA took much
longer to decode at limilar distances. I don't know exactly, i think it was
something between 4...6 days to produce a decode at DL0AO ?
But that was
with a longer TX period and in the deep winter. Not to think about the local
noise differences and antenna directivity... Jay uses a pure omni-directional
E field probe whereas DL0AO used a software combined cardioid antenna pointing
to EW exactly.
In the end there are some uncertainties which makes it hard
to determine the actual E-W/W-E attenuation. But it looks like something
between 10...20 dB is a good estimate.
Depending on the time it needs
to produce a lucky 5 character decode at W1VD, i will soon move to 17.47 kHz
again to start experimenting with Edgar in VK7, just a path of 16805 km (http://k7fry.com/grid/?qth=QE37PD35&from=jn49ik00wd).
Then
at night we can try to transfer a message to W1VD at 17.47 kHz to see the
difference of the attenuation. The old graphs suggest a big difference but i
bet it is not much, maybe 6 dB.
73, Stefan
Am 26.02.2018
15:15, schrieb [email protected]:
Stefan,
Thank
you for the reminder. All of the permeable-core selection/placement and
winding improvements come to mind when you mention that number.
Correcting
the sentence below: “(ERP ratio 16dB)…offset
a nominal E-W/W-E attenuation ratio (9 dB EW/WE ratio for 6Mm path) by
7dB.
Excellent
ERP, and glad that Markus pointed out the quantitative consistency of
same-month E-W and W-E link results with non-reciprocity at 8270
Hz.
73,
Jim
AA5BW
Thanks Jim,
ERP is 400 uW. Often discussed but my
statement here :-)
73, Stefan
Am 26.02.2018 04:31, schrieb [email protected]:
Congratulations
Jay and Stefan, and thanks Markus for the perspectives and reference points.
I have a rough recollection of Stefan’s estimated ERP, which would seem to
slightly more than offset a nominal E-W/W-E attenuation ratio, making
Markus’ two propagation observations particularly interesting, as is the
Forest question.
Fine
work Stefan and Jay.
73,
Jim
AA5BW
From: [email protected] [mailto:[email protected]] On
Behalf Of Markus Vester
Sent: Sunday, February 25, 2018 2:25
PM
To: [email protected]
Subject:
Re: LF: VLF DK7FC > W1VD 8.27 kHz EbNaut more
success!
Hi Jay, Stefan,
really good work, truly amazing!
Noticing that Stefan
hadn't sent another repeat last
night 24/25th, I wondered whether the experiment might
have already been concluded successfully - yes it had
;-)
Considering that Joe has been making the TA W-E path
with only 10 uW, in retrospective it seems not so surprising that
Stefan's much stronger signal managed to overcome the
E-W nonreciprocity. On the other hand, when Uwe had sent a
very long carrier in March 2014, no conclusive trace was ever
detected in Virginia. Now I wonder whether Stefan's recent
transmission has also been picked up in Forest?
All the
best,
Markus (DF6NM)
-----Ursprüngliche
Mitteilung-----
Von: jrusgrove <[email protected]>
An: ([email protected]) <[email protected]>
Verschickt:
So, 25. Feb 2018 19:26
Betreff: LF: VLF DK7FC > W1VD 8.27 kHz EbNaut
more success!
f = 8270.1000
Hz
Start time: 19.FEB.2018
22:30:00 UTC (daily)
Symbol period: 30
s
Characters:
2
CRC bits:
22
Coding
16K21A
Duration: 07:12
[hh:mm]
Antenna current: 700
mA
After a
successful one character reception earlier in the week, we can now report
the successful reception of a 2 character message. Stacking of 3
transmissions was required (0221, 0222 and 0223). There is also
a 0224 file but it has timing issues and may or may not be usable.
ebnaut-rx
V0.8
input file C:\EbNaut\DK7FC\sum212223.wav
sample rate 0.457240 per
second
rx frequency 8270
file start time 2018-02-22
22:21:17.790
polynomial 16K21A
crc size 22
number of chars
2
block size 34
symbol period 30.000
number of symbols 864
start
offset 537.000
freq offset 0.100000
cores 2
list length
500000
skipped 538.011261 seconds to start
initial reference phase
30.6
---------------------------------------------
found DX
list
rank 48426
reference phase 150,150,150,150
carrier S/N 11.04 dB in
38.6 uHz, -33.10 dB in 1Hz, -67.08 dB in 2.5kHz
carrier Es/N0 -18.33
dB
carrier Eb/N0 0.47 dB
info bit period 2273.68 seconds
symbol
error rate 373/864 = 43.171 %
Es/N0 from symbol errors -18.2 dB
Eb/N0
from symbol errors 0.6 dB
Shannon capacity 2.5 bits/hour
Shannon
efficiency 62.7 %
symbols file
C:\EbNaut\DK7FC\sum212223-symbols.csv
elapsed 52
seconds
---------------------------------------------
found DX
list
rank 17074
reference phase 120,150,120,150
carrier S/N 11.19 dB in
38.6 uHz, -32.94 dB in 1Hz, -66.92 dB in 2.5kHz
carrier Es/N0 -18.17
dB
carrier Eb/N0 0.62 dB
info bit period 2273.68 seconds
symbol
error rate 374/864 = 43.287 %
Es/N0 from symbol errors -18.4 dB
Eb/N0
from symbol errors 0.4 dB
Shannon capacity 2.6 bits/hour
Shannon
efficiency 60.5 %
symbols file
C:\EbNaut\DK7FC\sum212223-symbols.csv
elapsed 383
seconds
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