I conducted experiments on 160, 80 and 40 meters with trees as
transmitting antennas here in Florida, back in 1989. My interest began tied
to being a Meteorologist and my 35 year study of lightning and it's effects
and through my weather 14 year old consulting company. Alot of my consulting
customers were insurance companies, trying to avoid forking out loot for
lightning damage!
Most of us hams here in Florida have noticed that our non native, straight
as a board, grown for paper products, 100+ foot slash pines get struck by
lightning more often then any other tree. I consulted with forestry
officials and they verified that the sap in the slash pine contains more
electrolyte and is more conductive then any other tree. Basically we have
millions of 100+ foot pine trees acting like steel towers and with no spline
ball/porcupine system to drain off static electricity potential, this
buildup of + charge sends a leader skyward to meet downward moving leaders
and blammo lightning strike.
Anyway I picked a tree that appeared to be an approximate 1/4 wave in
height for each band, drove a very large nail into the base of the tree,
attached the center of the RG-8X coax to the nail via a copper alligator
clip and of course the braid to one 1/4 wave radial. I could not bring any
of the trees to any semblance of resonance or less then infinite VSWR and
got no useful detectable radiation at a near distance. Of course with a high
VSWR the rig would not put out full output, so I tried a variety of homebrew
tuners in line and still zilch, as you just can't resonate a six inch nail
through a tuner on any 160/80 or 40 meter bands.
At best the tree and it's leaves just absorb the RF like a dummy load!
73,
Thomas Giella, KN4LF
Plant City, FL
Grid Square- EL88wx
CQ Zone 5
ITU Zone 8
Email: kn4lf@tampabay.rr.com
KN4LF 160 Meter Amateur Radio Resources And More:
http://www.kn4lf.com
Florida Meteorological & Climatic Institute:
http://64.176.157.9/sub/fmci.htm
Giella Woodsign And Website Designs:
http://www.giellawoodsignandwebsitedesigns.com
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