I used to have system similar to what Eric, K3NA, recently described. I was
using a parallel dipole set up i.e. 80, 40, 20, and 10 meter dipoles connected
in parallel at the feed point. The total span between supports was about 180
feet. One end of this set up was tied to a rigid support using a fixed length
rope lanyard. The other end was supported by a tree. At the tree end I used a
six inch diameter pulley which was fastened to the tree by a 1/4 inch wire
cable. The tree was "protected" by 1 x 2 x 8 inch wooden strips between the
cable and the tree. A 1/2 inch manila rope was fastened to the dipole set up,
and ran thru the pulley and down to a counter weight which consisted of three
cinder blocks a few feet above the ground. The rope was protected at the cinder
block end with a sleeve made from old garden hose. As the tree would sway in a
heavy wind, the rope would run up and down thru the pulley keeping the antenna
under approximately constant tension. I even had an ice storm situation where
the antenna sagged to the ground under the weight but recovered nicely when the
ice melted. I know there will be comments on the use of manila but it was cheap
and lasted for three years until I moved. I didn't use a second pulley. When I
wanted to fiddle with the antenna, I unclipped the cinder blocks, attached a tag
line to the rope and lowered the antenna. Slick.
Roy Breon W9GTC/1 in West Peabody MA at the time.
_______________________________________________
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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