From: "Mike Dennison" <mike.dennison@rsgb.org.uk>
To: rsgb_lf_group@blacksheep.org
Date: Tue, 20 Mar 2001 12:40:02 -0000
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Subject: LF: WOLF again
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G3LDO wrote:
 
>  When I run WOLF under Win 98 for a split
> second I get a small black window (similar to running DOS) but it
> disappeared so fast I wasn't able to read it. By repeated running I found
> that I hadn't included the .wav file (looking through the documentation,
> belatedly!, I see this is necessary).

Peter, the program is accessed via the "DOS" window, though it isn't a DOS 
application (confused? wait till you try to run the program!). This window tends 
to be hidden these days but try all the options from the START button until you 
find Command Prompt.

> I also understand that only off-line processing on receive is available.
> >From this I guess that what I should have done was to make a .wav file of
> Jim's signal and process it later. In the presence of QSB this could make a
> QSO a bit tricky.

At present only a pre-recorded file can be analysed - but this is an advantage 
in these early stages because you can keep readjusting the numerous 
parameters and re-checking the same signal until you have it optimised. I 
would hope that eventually all of this will be automated so that the computer 
can do all of the tedious work for you.

As for QSB, the whole point of WOLF is that it is better than QRSS in the 
presence of QSB. QRSS stretches the message over an hour or so which is 
fine so long as the signal stays up for long enough. WOLF, as I understand it, 
sends a fairly short message over and over again until it is received 
satisfactorily - in other words the integration is done in parallel, not in series 
{experts, please tell me if I have it wrong}. So you could take advantage of a 
10 minute peak in conditions to pass the message rapidly (whereas QRSS 
would still be sending slowly), or conversely you can ignore deep QSB 
because the receiver will find the signal again later.

> >From what I have read about WOLF it does appear to be a good system for
> extracting data from weak signals buried in the noise and if the claims are
> to be believed it has some dB improvement on QRSS systems.

I am still skeptical, but Jim's reception in the USA at only his first attempt 
indicates that there are real possibilities when everything is optimised.

> However, in my case very narrow band QRSS has the great advantage of being
> able to work between the very strong Loran lines received here.  QRSS and
> Argo now has given us a system of the utmost simplicity, which encourages
> lots of users. In addition it enables us to know what is going on around us
> and the ability to read several stations at a time in a very narrow
> bandwidth (a valuable asset in propagation studies).

Loran is listed as one of the potential problems. However, it is suggested that a 
software comb filter can be produced, and that the Loran lines can even be 
used to maintain frequency accuracy.

I agree that computer-only modes - as distinct from modes where the 
computer displays something the brain can interpret - leave the operator with 
a feeling of remoteness. I have already identified the problem that random 
QSOs will be almost impossible with WOLF. What would be useful would be to 
incorporate a spectrogram into any front-end software for WOLF. Thus you 
would be able to see what was going on, and perhaps someone looking for a 
WOLF QSO would send a string of 10s dashes (or Ws in QRSS?) before his 
transmission so that he could be identified and tuned to.

The important thing, I feel, is to spend some time this summer evaluating and 
refining this software, and operating practices, so that it is useful next winter.

For me, the ideal solution would be to have real-time WOLF, with an easy 
front-end, combined with the means to transmit and receive 
CW/QRSS/DFCW, all in one piece of software/hardware. This would avoid 
fragmenting the activity. It would also allow the best mode to be used for each 
set of circumstances.

Thanks to all concerned in developing WOLF. I am sure it will become a more 
friendly application. I still remember the first QRSS reception using 
Spectrogram when you needed a stopwatch to time the dots and dashes as 
the display was only a few seconds wide. I'll bet the first HF SSB QSO was 
hard work, too.


Mike, G3XDV (IO91VT)
http://www.lf.thersgb.net