Rich wrote:
>>I used to think that this was the case until I sold the original Plywood
Box/8170 amplifier. Even though I had measured the amplifier's voltage-gain as
x10 with an oscilloscope (20db power-gain), but on the air, I measured 20 -
23db with my calibrated S-meter. Other people with calibrated S-meters reported
the same crazy thing. Others who saw the 23db change said that Stanford
(University) Research Institute had observed something similar during their
ionospheric heating research project<<
Al wrote:
>>Again.... until anomalies are explained, they are just that.
That's why we have phrases such as "observable phenomena".
Imagine the plight of theoretical physicists, like Einstein, who posulated
his thoughts but waited years until proof was found. Until proven, they
remained
theories. Your measurements are not in question - only the reason behind
them.<<
I have noticed this effect and I was glad to see more "proof" in Rich's post.
See my old propagation article at
http://members.aol.com/ve3bmv/bmvpropagation.htm
where I speculated (observable phenomena) that we are propagating signals
more as refraction/ducting rather than pure reflections from the ionosphere. In
that case it would make a difference how signal gets into the duct. At some
threshold it might not make it, at some other it does. That jump in power
levels
can be seen as not linear or corresponding to power levels at the transmitter.
We are not dealing with coax that you can apply ohms law to. There also has
to be a distinction when we are looking at signal levels at the RX site. Is it
at direct signal path, or is it a DX distance after going through
atmosphere/ionosphere finicky properties. 160m is a good example of weird stuff
happening.
There are cases when DX signals are not exactly proportional to the power
level variations at the TX site.
I saw cases when after the contest propagation seems to be enhanced for about
half an hour and then fades rapidly (ionospheric heating from all them kWs).
I had arguments about this with "guru" W8JI who insists that ionosphere is
"linear" when I know and saw some weird things happening not conforming to
"linear" propagation with my Razor Beams
http://members.aol.com/ve3bmv/Razors.htm
That one dB as G3SEK pointed out makes whale of a difference in special
cases. Add to it ocean salt water QTH and we are talking 10 - 15 dB of
advantage on
RX/TX.
Like it or not, there is some weird stuff happening. Differences measured are
not due to goofy S-meter calibration (attenuators used) or inaccuracies in
measurement, but due to "weird" behavior of media - atmosphere, ionosphere and
wave travel mechanism. Some contesters know it and use it.
73 Yuri, K3BU.us, VE3BMV
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