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The little Wolf signal was on air from 23:05 to
07:15 this morning, with ERP down by a dB or so because of snowfall. The
phase monitor showed a continuous steady frequency without a
single glitch.
Thanks again to all who have kept an eye open for
me. At least we know if we didn't succeed tonight, it was really due to
suboptimal propagation and/or insufficient ERP from my side.
Best 73, and have a nice
weekend
Markus (DF6NM)
Sent: Saturday, January 28, 2012 12:01 AM
Subject: Re: WOLF: 135975 Hz, 10 b/s again
Hi Andy, LF,
actually there is no carrier line in the WOLF
spectrum, it's BPSK with a pseudorandom spreading code. In a spectrogram
it resembles a 10 Hz wide noise band, which will be pretty much
undetectable at any DX range. Actually a kind of spread spectrum mode, not
unlike the GPS modulation (pssst ;-).
I think I have proven (and resolved) my soundcard
phase-glitch problem. The attached trace shows a local audio test, with
a WOLF signal generated on 1475 Hz. It is doubled in SpecLab's AM
demodulator to regenereate a carrier at twice the frequency, which is phase
compared to an hardware generated Rb-derived reference carrier.
I have employed SpecLab's RDF mode to display phase as colour
(retarding R-B-G-R). The first half shows the result from WOLF-Gui running
on my "Grabber Notebook", which has a number of programs
running. Besides the gradual phase roll due too a very minor frequency
offset, there are jumps every few minutes. This is a bit nasty,
as Wolf will still decode such a signal when it is strong, but not be able
to go to its full sensitivity by using long coherent integration. The right half
after 21:40 shows the practically perfect output from the Atom Netbook, the one
which I have also used during several VLF
transmissions.
So, maybe it's worth another try. Will put the
"good" WOLF signal on air a few minutes after 23 UT, QRG 135975 Hz, 10
b/s.
Best 73,
Markus (DF6NM)
Sent: Friday, January 27, 2012 7:54 PM
Subject: Re: WOLF: 135975 Hz, 10 b/s
My report is the same... no
decodes... I wish as an after thought that I had ran SpecLab also, to look for
the carrier...
maybe next time
73:
Markus
No joy here either.
Jay W1VD WD2XNS WE2XGR/2
----- Original Message -----
Sent: Friday, January 27, 2012 7:50
AM
Subject: Re: WOLF: 135975 Hz, 10
b/s
Many thanks Andy, John and Dex for looking out
for my WOLF signal. The TX was
running without interruption from 23 to 7 UT, PEP about 0.5 W
ERP.
One thing I still don't trust is the continuity
of the soundcard output. I guess the glitches
which occasionally appear in
QRSS dashes might corrupt the long-term
phase-coherence which is required for deep WOLF decoding. Will
have to look into that before the next attempt.
Best 73,
Markus (DF6NM)
Sent: Friday, January 27, 2012 12:53 PM
Subject: Re: WOLF: 135975 Hz, 10 b/s
Markus,
No luck. Not a quiet night, and TA prop does not
seem to have recovered.
John, W1TAG
On 1/26/2012 10:02 PM, John
Andrews wrote:
> Markus,
>
> Nothing seen as of 0300, other
than the usual infinite number of monkeys
> typing away. Will let it run
overnight.
>
> John, W1TAG
>
> On 1/26/2012 5:39 PM,
Markus Vester wrote:
>> WOLF ... good idea!
>> My TX antenna
has been pushed up again tonight, and I intend to howl for
>> a
couple of hours, starting 23:00 UT at 10 b/s speed.
>> As CFH is
still sitting smack in the middle of the band, I'll move close
>> to
the lower edge, squeezing into a narrow HGA-sidebands gap on
*135975
>> Hz* (that is unless you may have other
suggestions).
>> Best 73,
>> Markus
(DF6NM)
>>
>> *From:* John Andrews <mailto:[email protected]>
>>
*Sent:* Wednesday, January 25, 2012 3:30 AM
>> *To:* [email protected]
<mailto:[email protected]>
>>
*Subject:* Re: LF: WOLF DATA MODE S/N FIG ?
>>
>>
Graham,
>>
>> There is no single s/n figure or specified BW
in which to measure it.
>> WOLF works by building copy up over a
period of time, and assuming good
>> frequency/phase stability, a
half hour or more is practical.
>>
>> The data rate is
fairly fast, 10 b/s, with a 960 bit message, so that a
>> complete
frame of data is sent in 96 seconds. You get three quick
>> reports
in the first 96 seconds, and then decodes every 96 seconds
>> after.
Each message is 15 characters, with no rules about callsign
>>
format.
>>
>> Tests done some years ago show it roughly
equivalent to QRSS60 in terms
>> of signal level. It does give some
clues as to whether a signal has been
>> locked-in, and has the
possibility of partial copy, unlike some "all or
>> nothing" modes.
Fifteen characters in a half-hour is of course much
>> faster than
QRSS60 would permit. 2-way QSO's are fairly easy with some
>> advance
agreement on what to do with the 15 characters.
>>
>> The
downsides are the need for a linear transmitter system (as this is
>>
PSK), receiver/transmitter stability and frequency accuracy. It works
at
>> 600 meters, but is fairly useless at 160 meters and
up.
>>
>> The newest version is by DL4YHF, and may be found
at:
>> http://www.qsl.net/d/dl4yhf//wolf/ .
>>
>>
Note that this version has 5 b/s and 20 b/s variations. Testing
has
>> shown that the program tends to provide copy in the same
amount of time,
>> so there's no overriding advantage to
either.
>>
>> John, W1TAG
>>
>> On
1/24/2012 7:27 PM, Graham wrote:
>> > WOLF DATA MODE S/N FIG
?
>> > Long time since I used wolf , anyone have the
>>
> expected decode min s/n level ?
>> > and now what s/n was ref
to , as changes
>> > may of taken place over time
>> >
Tnx -G.
>> >
>> >
>> >
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>>
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