R: [TowerTalk] Arrival angles and sunspot number

[Maurizio Panicara]

Angles depend first by height and density of the ionosphere layer producing
the reflections and second by the absorbtion of the lower ionosphere layers
that behave as a lossy media (lower the angle, longer the path through it)
for the wave  passing.
It's evident that a number of parameters vary along the daytime, the
involved band, the period of the year and somehow also because of solar
flux, but I don't think the sunspot activity justifies an extra devoted
special antenna arrangement or a substantial modification in YT indications.
My experience confirms that lower angles are always a good choice to
"extend" the useful time in a stated band (when it opens and closes)
meanwhile chanonical elevation angles seem to be better in the middle of the
band opening itself.
Same evident is that with a low solar flux the lower antenna angles increase
their relative effectiveness meanwhile the low antennas with high angles,
still useable with 200 SFI, become nearly useless as a dummy for the very
long distance contacts.
Not very scientific, but best solution is definitely to have choices and
chances to select different antennas and wave angles.
Lower angles than generally agreed (down 3 times or more) are the good tool
in some moments, higher angles than aspected make sometimes the important
difference, and the sequence repeats several times in a single day.


73,
Mauri I4JMY

----- Original Message -----
From: Pete Smith <n4zr@contesting.com>
To: <towertalk@contesting.com>
Sent: Sunday, April 23, 2000 8:29 PM
Subject: [TowerTalk] Arrival angles and sunspot number


>
> The arrival angle tables calculated by N6BV and included with the Antenna
> Book and YT are averaged over the full range of sunsport numbers and times
> of year.  does anyone know if there is a systematic variation in these
> angles with sunspot number?  In other words, during a peak should these
> numbers be systematically biased in a particular direction -- for example,
> is there relatively more high-angle propagation over a given path under
> high-sunspot conditions?  Are such generalizations possible, if only on a
> band-by-band basis?  I don't have a copy of "All the Right Angles," which
I
> assume has the raw data, but I'm hoping someone has already researched
this.
>
> I'm looking for the answer in connection with a possible new way of
> evaluating antennas that I'm developing.
>
> Thanks for comments.
>
>
> 73, Pete Smith N4ZR
> n4zr@contesting.com



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