First, I am no authority on insulated base towers but I put up 78 feet of
25G during the summer of 2008. I modified a section of tower to accept 3
large power company glass insulators (a similar set of these has been in use
on another tower I know of for about 30 years with no problems). They are
about 8 inches in diameter and maybe 10 inches tall. The tower is guyed at
25, 50 and 75 feet with philystran cable. I have a two element 40 meter
beam on the top and the mast takes the total height of the tower to 85 feet.
There are sixty radials buried for the tower radial system (some 6000 feet
of wire). The matching is done through two LC networks remotely selectable
from the house (the 80 meter network is hand adjusted for the phone or cw
portions of the band). I also use a relay system to completely disconnect
and isolate the tower from the 40 meter beam coax and the rotor cable when
loading the tower on 160 and 80.
The tower seems to play well on TX and now am working on what type of RX
antenna to erect.
73 and Merry Christmas to all from -20 degree Bozeman, Montana.
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