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Old February 27th 08, 10:48 PM posted to rec.radio.amateur.antenna
Jim Lux Jim Lux is offline
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First recorded activity by RadioBanter: Mar 2007
Posts: 801
Default Wire Antenna/ Tree interaction

marc wrote:
I'm a noob, and I'm considering installing a wire antenna using the
sole tree on my lot as one end. My question is "Is it dangerous if
the antenna touches the tree branches/leaves during transmit?" I'm
less worried about performance right now and more safety.

Marc
W5AMP


how much power?

I used to have a dipole outside my apartment and the wires would touch
some of the leaves/branches. I used a tuner at the feedpoint. On 40m
(only), running 100W, it would arc to the tree on damp nights.

So, the real answer is, it depends. 100W dissipated in one spot could
probably start a fire. a few watts lost in miscellaneous crackling and
sparks, probably not.

If your wire antenna goes to an insulator, then to a rope/cable that
goes to the tree, then you're probably much better off than just
flinging the antenna wire through the branches. (the latter is popular
with backpack portable...)



And, if you're that close to the tree, you're probably inducing some RF
currents in the tree, so RF fields safety is an issue. Again, it
depends. Power, operating mode, style of operation, whether there's any
access controls to the area where the tree is, how high the antenna is,
how big the tree is, etc.