Hi Markus, Edgar,
Well i think it is most promising to start with the good old DFCW-180.
If the success is clear and if there is no other station announcing RX
attempts, then we could continue to try other modes.
Markus, we're running DFCW-180 in 11 mHz, not DFCW-90. This has proved
to be the best combination, at least from my point of view.
Your table states that a detection in OP-32, using your correlation
software, would result in a clear decode if the signal is as good as
"M" copy in 11 mHz, right? What happens if there is QSB during that
time? The events of > 30 minutes without QSB are quite rare i think.
It looks like i have to use a kite antenna here on the building :-)
73, Stefan/DK7FC
Am 03.08.2013 13:47, schrieb Markus Vester:
Hi Edgar, LF,
this looks like a great project, and
it's good to see a live grabber from VK7 again. So with that extra
distance you might reach the top three in the DX list... unless Mike,
Bob, or someone else takes the challenge and picks up Stefan in ZL ;-)
Orford - that's surely a nice
location. On the occasion of attending a conference some 15 years ago,
we were lucky enough to be able to drive around the Tasmanian east cost
for a few days. We were much impressed by the beauty of the landscape,
the clear skies, and the friendly and easygoing manner of the
inhabitants.
Are Stefan and you intending to
focus on DFCW only, or try other modes as well? Attached beneath is a
short table, lining up approximate sensitivities for a few weak-signal
options.
Best 73,
Markus (DF6NM)
Mode norm.SNR SNR bandw.
duration remarks
dBHz dB mHz minutes
carrier -18 14 0.4* >30 highly significant peak in 0.4
mHz spectrum
DFCW-90 -12 6 11* 42 marginal "M" detection in
spectogram
DFCW-90 -6 12 11* 42 fully readable "O"
Opera-32 -1 8 125 33 reliable decoding by Opera
software
Opera-32 -12 21 0.5 33 correlation detection of a
coherent transmission
WSPR-15 -4 3.5 180 15 decoding by WSPRX software
WSPR-30 -7 3.5 90 30 accelerated replay to WSPR
software
MFSK37 -9 14 3.3* 25 visual decode or automated peak
search
Notes:
- SNR thresholds are only approximate.
- SNR referenced to carrier power (not average).
- normalized SNR in 2.5 kHz can be obtained by subtracting 34 dB from
dBHz.
* noise bandwidth is 1.5 times the stated FFT bin width.
- duration to send "DK7FC" message (19 dashes and 4 spaces).
- MFSK37 is absolute frequency keying, sending one 5 minute dash per
character.
Sent: Saturday, August 03, 2013 1:28 AM
Subject: LF: DK7FC Equinox reception
Hi,
During the last three Equinoxes I have attempted to receive DK7FC's
signal at QE37pd, Moonah, Tasmania.
The best result was achieved last April.
Refer to:
https://dl.dropboxusercontent.com/u/101251787/DK7FC%20reception.pdf
I decided for next Equinox period, (20th September 2013), that I would
attempt to better the distance previously achieved.
The results will be available on the internet.
https://dl.dropboxusercontent.com/u/101251787/testIDC.html
At present the equipment is set-up at QE37pd, and when possible Stefan
is running test transmissions from 19:00 to 22:00 UTC.
By the middle of August the system is to be set-up at Orford, on the
east coast of Tasmania, to operate until the end of September.
http://no.nonsense.ee/qthmap/?qth=QE37wk
The frequencies of DCF39 and HGA22 signals are also being monitored to
determine the propagation.
So I invite members to participate by monitoring the progress via the
web images.
Regards, Edgar
Moonah, Tasmania.
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