> I went outside and took the sharp picks of my Fluke
multimeter and
> stuck them through the bark into the wet of several
different kinds of
> live trees. An oak measured over 1 meg across two feet
vertical on the
> trunk. One of my maples measured over 100K and
interestingly did a
> very slow charge like an electrolytic capacitor, measuring
over 500K
> after five minutes.
I actually measured the resistance of a freshly cut pine
tree by attaching metal plates to each end of a one foot
piece, and it as in the many hundreds of ohms per foot at
radio frequencies.
This was in response to written claims that trees can be
used as antennas, and that the "fractal" shape of trees
makes them good radiators.
So Guy, we have a big conflict now. Some people claim trees
make wonderful antennas which directly implies they will
affect signal levels severely. Others claim they do nothing.
No one can offer any direct HF measurements of how many dB
change XX distance through trees affects signals, but many
people have opinions. Some opinions are strong, even without
any type of data at all.
This is why it would be very valuable for someone to
actually quantify the effect at HF with a good test.
Otherwise, it is a popularity contest.
73 Tom
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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