At 12:39 PM -0500 11/20/02, Pete Smith wrote:
>At 12:21 PM 11/20/02 -0500, you wrote:
>>An obvious _possibility_ is that all parts of all elements of a
>>quad are grounded for DC, whereas one-half of the driven element of
>>a Yagi (the half connected to the center conductor of a coaxial
>>feedline) might not be. An ungrounded antenna is noisy --
>>extremely so in my experience.
>>
>>What about _your_ Yagis?
>
>
>So then a yagi with a hairpin match across the feedpoint should be
>quieter than one without?
Yes -- IF the explanation that I suggested as a _possibility_ is, in
fact, the (chief) explanation. However, I think that the suggestion
of Michael Tope <W4EF@dellroy.com> regarding the vertically polarized
component of a horizontally polarized quad antenna's radiation
pattern vs. that of a horizontally polarized Yagi is an excellent
one, worthy of examination.
As he points out, so-called horizontally polarized antennas typically
have nontrivial response to vertically polarized radiation arriving
from off-axis or "out of the plane." E.g., a simple horizontal
dipole does.
-Chuck, W1HIS
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