> I believe the K6STI loop and even
> the Flag/Pennant family are getting unfairly slammed in the
> informal ham 'press' such as the Topband group.
I don't think so Dave.
I think it reasonable to point out as antennas are made smaller and
smaller, they generally become more and more critical to build.
It is also reasonable to point out that the K6STI loop is very critical
to construct, because the nature of the antenna makes it very
sensitive to balance. It is so insensitive, it might not be possible to
balance it without special "tricks" or effort.
As a matter of fact, the very thing that makes the K6STI antenna
NOT want to work is part of what makes Beverage, EWE, Flag,
and Pennant antennas "want to work"!!!
For those of us with small well-balanced loop antennas, I'd like to
suggest a little experiment.
Take the small loop antenna and lay it over flat near the earth's
surface, and watch the general levels of all signals. What you will
see is a properly balanced loop just about goes dead, or at least
has a very major reduction in sensitivity, when laid flat a few feet
above earth.
The reason for this is simple. The earth effectively "short circuits"
the horizontally polarized electric field. The loop, Beverage,
Pennant, Flag, and even the K6STI antenna don't like to respond
to horizontally polarized signals because of the earth. There just
isn't much horizontally polarized signal there, if the earth has any
reasonable conductivity. What horizontal component there is
mainly comes from very high wave angles!
On the other hand, vertically polarized signals are re-enforced by
the earth. Antennas near earth "want" to hear vertical signals,
because the earth tends to re-enforce vertically polarized signals
and cancel horizontally polarized signals.
Actually, this is also the very reason ground wave propagation
must be vertically polarized, and why the noise that propagates
along the earth for a distance is all vertically polarized.
We might wish otherwise, but we can't have mother earth treat one
antenna in some special way!
We aren't being unfair or pessimistic in telling the truth.
73, Tom W8JI
W8JI@contesting.com
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