In a message dated 4/5/2001 19:21:01 Eastern Daylight Time, tree@kkn.net
writes:
>
> It is probably true that the "average" station in the contest is
> probably 10 - 20 db louder than the average station on the band
> after the contest. So, I would expect my S-meter to move a lot
> less after the contest and the guys with dipoles and 50 watts
> are able to find a clear frequency.
>
> As far as determining if Amateurs can generate sufficient noise to
> effect the propagation medium - I think it is pretty obvious to
> anyone listening to the HF international broadcast bands that they
> have a very significant presence in the equation. Even looking at
> the energy between 7.1 and 7.3 megaHertz makes a pretty convincing
> case that the Amateurs are just a drop in the bucket.
>
> Finally, for those who think the ionosphere might be non-linear -
> I think they need to think about what would happen as a result.
Let me try to explain what we have observed. We used to have skeds with OK2RZ
(when I was VE3BMV) around 0000z on 40m. You get the feeling for signal
strengths for particular propagation patterns. You can tell when signals are
10 - 20 dB better (on crummy uncalibrated no good Smeters) at particular time
(same antennas, same rigs).
We used to meet after the contest (forgive me for not showing up on 3830) on
the same band, and we noticed that our signals would be 10 - 20 dB better
than "normal" for about half an hour, right after the contest, then revert to
"usual" signal strength experienced outside of contests.
It was like a clockwork, reading about heating of ionosphere (and this not
that outrageous) we figured it could be the result of contest activities, so
many kilowatts around those frequencies could cause enhancement (it could be
frequency selective). I have heard some stations reporting and having
enhanced propagation when sitting on frequency, calling CQs and being able to
hear stuff that wasn't "hearable" otherwise.
I don't know what exactly is going on, just stating what was observed. No
government contract to study the phenomena, and no "scientwific" paper
available.
As far as linearity of ionosphere and propagation, if you looking for
linearity (and distortions) like in the amplifier, that ain't there. But
there are differences in the paths between two locations. Those with stacked
beams and various angle antennas can try this. Ask for report on top, bottom,
stack when you transmit, then switch same sequence on receive. I have found
around 60% of disagreement between two cases. Shape, angles and condition of
layers providing reflections and refractions are not always the same at both
ends. So there is no exact reciprocity or "linearity" in propagation. At the
times I would see differences like UA9 would be coming under higher angle
than OK at the same time. Not what books and pretty pictures (out of scale)
in textbooks show. If you think this is fantasy, try it if you have stacks.
Then you (W8JI) make fun and personal attacks (when you run out of arguments
and are WRONG).
Funny that "stupid" VE3BMV with all his "crazy" ideas and observations
somehow beat all those "smart, all knowing" guys and cornered number of world
records from the city lot, Eh? Not long ago W8JI called me pathological
scientist for stating that there is skewed path and high angle propagation on
160, now he is "guru" on the subject.
Am I the only "idiot", or has anyone else experienced similar things?
You can take it for what it is worth or make fun of it. I sleep well and I
keep adding dBs for that edge over competition.
73 Yuri, K3BU, VE3BMV
da vertical beach BU/m
--
CQ-Contest on WWW: http://lists.contesting.com/_cq-contest/
Administrative requests: cq-contest-REQUEST@contesting.com
|