[TowerTalk] Beverages and Trees

K7GCO@aol.com K7GCO@aol.com
Wed, 8 Mar 2000 16:21:39 EST


In a message dated 08.03.00 10:13:58 Pacific Standard Time, 
alsopb@gloryroad.net writes:

<< 
 "Just as it is not recommended to put up vertically polarized antennas
 between tall trees, it is not a good idea to run a Beverage antenna
 through the woods"
  >>
    This is particularly true with "Iron Wood" and "Silver Maple" Trees.  
They have been know to act as "Log Periodic Reflectors and Directors.  In W6 
land, strange Forrest fires have started without lightning?  I once showed a 
Pine tree used a Circularly Polarized Log Periodic and feeding it just by 
bending the 50 ohm limb down for a "Limb O. Match."  Or you can just drive a 
nail into the root system for a "Root Ground" already there and gamma 
matching at the desired feedpoint Z with a series Xc made from a circular 
strip of bark around the trunk of the right width and location.  The bottom 
limbs are usually 1/4 Wave Limb above the Root Ground to RF but not 
electrostatically disconnect it from the Root Ground.  It's a very quiet tree 
for receiving.  

I then saw in a W.W.II Radio Manual where they gamma matched a tree for an 
emergency antenna and used fence wires for beverages.

There is a "Plant Stimulator" you can buy where you stick 2 nails in the pot 
on each side of the main stem and pulsed it with square waves.  I've had a 
vertical in a tree for years and that tree has grown taller than the rest 
over 45 years with "RF Stimulation".  Regardless of the conductivity and 
capacitive affect of the wire next to it, it's compensated for by the length 
of the main wire.  No Conflict.  I couldn't run radials so I ran spikes into 
the big roots.  The coax was buried at night and bark colored insulated wire 
went up the tree under the bark for the 1st 6'.  The owner still doesn't know 
it's there.  It also had great bandwidth.  I've also stashed 3 and 5 band 
verticals in neighbors trees with the base about 30 feet off the ground.  The 
green radials were thrown over the limbs of the right length.  There were 
20,17,15,12&10M radial limbs right there.  The coax was cut into the bark for 
6' and the antenna was camouflage painted.  It's called "Stealth Creative 
Antenna Installing."  Trees are great friends-even the neighbors at night.  A 
yagi in a tree is a tough installation as it gets wiggled a lot more.  I did 
have a tri-band dipole for a pick up antenna for beam pattern testing in the 
top of a tree.  The coax shield to the antenna on top was loaded as a top 
loaded 1/2 wave on 80 with an L network grounded to the "Root Ground."  The 
matching system was just on my side of the property line. It worked great.  I 
had no way to install the equivalent without the tree.  

Note! This is all absolutely true.  I did not just make it up--maybe just a 
small part. K7GCO     

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