At 07:01 AM 5/7/98 +0000, you wrote:
To: <towertalk@contesting.com>
>> Date: Wed, 06 May 1998 12:50:40 -0400 (EDT)
>> From: W7NN <W7NN@aol.com>
>> I've never seen a study on resonant trees but maybe others have experience
>> with this area.
>>
>I got "roped into" measuring the resonant frequency of tree by some
>guy who thinks they make great antennas because they are shaped like
>
snip
>Has anyone ever seen actual properly measured and documented data on
>this?
>
>73, Tom W8JI
>w8ji.tom@MCIONE.com
>
Back a few years ago I was involved in some laser velocimeter development
where we took advantage of Mie scattering. This is basically the forward
scattering of light from dielectric particles whose dimensions were
of-the-order-of the light. The losses of energy were trivial, only the
spatial distribution was changed. I expect this type of scattering would
be involved in the propagation of radio waves (same type of electromagnetic
radiation) through trees (dielectric "particles".) Therefore, it may be
that the direction, i.e. pattern would be changed but not the total
radiated energy. Just a thought.
I too would like to see some data on this since my 80/160 array hangs from
tree limbs in the woods but I've never been able to see any difference in
performance, summer to winter in GA, except on the higher bands where I get
the "feeling" that the gain is less. Of course, on 2M there's no doubt that
it's more difficult to reach the repeaters. One 2M path,over the center
of Atlanta, changes daily as the city heats up. Is this due to refraction
in the moisture over the town?
Clay, K3IX
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