Intercontinental modes - what next?]

[Andre' Kesteloot]

Larry Kayser wrote:

> Jim and the others who have commented - Wonderful, a great start to a
> discussion that is needed at this time of year.
>
> I offer that there are two, as I see it, distinct directions we are moving
> to, the first is the use of DFT processes for detecting power in smaller and
> smaller buckets (read as longer and longer information bits) and secondly
> those who are into using information coding to decrease the time for the
> transfer of information at the expense of needing a higher level of signal.
> The later is what I consider to be the more tranditional mode of amateur
> radio operating.
>
> Jim's three step "wish list" is an excellent documentation of the second
> mode, a more traditional orientation, of item two above.  I wish those who
> wish to focus on what I call the second mode well, and good luck going down
> that road - I however will not be with you in that area of focus for next
> year.
>
> For the rest of the 2001 spring season I am available to run long duration
> 90 second per bit QSO attempts or to have a special session of transmitting
> WOLF data if there is any interest in Europe in having such a test session.
>
> WOLF is extremely difficult for me to send, the I/O implementation choosen
> by Stewart when mixed with my situation here makes if very difficult - but
> if there is interest I am available to run a couple of overnight tests
> before the end of this season.  I have loaded 18 hours of WOLF in one file,
> in 25 minute segments, thank goodness for 30 gigabyte hard drives!   I will
> have to build up some hardware and do a fair amount of software to make WOLF
> work from here - if the interest is present I will do it.  The operative
> words here are to set a time period and a reasonable level of participation
> from Europe.
>
> My work going forward from here will focus on extream weak signal detection
> which continues with the goals I set here when I came to the LF community
> some 18 months ago.  My focus will now shift to Time and Frequency coherency
> to not worse than a part or two in 10-11th.  I now have GPS controlled
> systems at both my home and the remote site, they are not yet complete but
> they exist and will be completly functional by the fall.
>
> The status of LF operation from Canada remains tenuous.  The TransAtlantic
> II project that was the basis of Canadian participation on LF has been
> eclipsed from bordering on believability and achievability a year ago to
> common practice in so short a time as to place in question much of the
> "common wisdom" of the day.  A plan for an LF allocation in Canada is before
> our regulatory authority, the issue is - will enough time and resources be
> available to do the work of authorizing general use of the LF band be
> available in the near future?
>
> The next issue is how many amateurs will build the systems and learn the
> tricks to have an active LF community - there will be at least a year of
> growth needed.  With just three transmitting stations in Canada now we have
> seen the limits of LF paticipation, aural only operation only by Jack,
> VE1ZZ, and severly hampered (foliage challenged)  LF operation by Mitch,
> VE3OT and my own setup here in eastern Ontario.  The situation of an LF
> allocation in the United States is certainly not understood by myself - but
> it can be said there is a community waiting for the opportunity to make use
> of an LF allocation, but at the moment there is no certainty of
> participation and this community will need growth time as well.
>
> This being said, there is also some opportunity in the information coding
> area.  WOLF uses an internal synchronization process, very costly in
> information bits.  There are opportunities in Time Coherency as well as the
> Turbo Product Codes that are achieving very high levels of performance
> approaching the Shannon limit.  (By the way Dr. Shannon passed away only a
> month ago I learned in yesterday's newspaper).  I personally want very much
> to understand these coding processes and demodulation/modulation methods
> enough to write my own code and experiment with them on the air, this is the
> only way I will return to the information coding area of operation that I
> mentioned above.
>
> The current operational status from here is that I continue to see many
> trace level weak signals from Europe almost every night.  Many of them are
> using bit rates that result is complete smearing here and are not readable
> at all.
>
> I have tested the 7 level FSK coding on 160M and as well on 20 Meters
> (hiding in amongst the DX Beacons on 14100 kHz - they are spread out over
> about 150 Hz - terrible waste of spectrum Hi).  I do not recommend this work
> go further, there is far greater value in the information coding mentioned
> above and it is important to focus our efforts in order to make meaningful
> progress.
>
> I have no idea why but I have still not seen a single recognizable DFCW
> signal on this side of the Atlantic.
>
> The two different directions that I mentioned at the start of this memo, DFT
> with longer and longer bits, and the use of information coding to increase
> the signalling rate are I suggest critical to the evolution of LF.  I ask
> each of you to consider and comment on this segmentation and what you see as
> your participation in the "speaking slowly" mode of operation.  I am keen to
> find others to work with in this area of extremely weak signal
> communications.  I encourage others who might wish to focus on really really
> weak signal work to contact me directly.
>
> Larry
> VA3LK