The advice I have received so far is to go with a large conduit. I am
therefore planning to install 3" conduit to a Hoffman enclosure. Since the
tower tilts over, I'll likely secure the enclosure to Unistrut embedded in the
concrete base. Saturday is the anticipated pour, so I'll let everyone know how
it turns out.
Original message by Bill Ogden, W2WO
"I did something similar (1.5 inch sweep in the concrete base) of a former
tower. Big mistake. Use at least a 3" conduit. Schedule 40 seems to be
I have a coax switch control cable, a rotator cable, two coax cables
(buryflex), and one SteppIR control line. They are very small in a 3"
conduit, but pulling another cable is already a nontrivial job. Remember
to use a very good "messenger" or "tag" or "pull" rope. I used a 1/4"
dacron line that should stand up to moisture. There always seems to be
condensation in the conduit.
I used two 90 degree schedule 40 turns at the antenna end and I remove
these when pulling a line. They just sit on top of the vertical 3" conduit
that emerges from the ground. (On my current tower, I did not embed the
conduit in the tower base.)
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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