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Re: WOLF: 135975 Hz, 10 b/s again

To: <[email protected]>
Subject: Re: WOLF: 135975 Hz, 10 b/s again
From: "Markus Vester" <[email protected]>
Date: Sat, 28 Jan 2012 00:01:58 +0100
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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-G-B-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:
 
Andy - KU4XR - EM75xr - Friendsville, TN. USA
Coordinates: N: 35º 43' 54" - W: 84º 3' 16"
http://lwca.org/grabbers/ku4xr/
http://www.myspace.com/beaconxr
http://ku4xr.webs.com
http://lwca.org/community/YaBB.pl

From: "[email protected]" <[email protected]>
To: [email protected]
Sent: Friday, January 27, 2012 8:41 AM
Subject: Re: WOLF: 135975 Hz, 10 b/s

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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>
>
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