In a message dated 8/29/2006 8:30:16 P.M. Greenwich Standard Time,
n4zr@contesting.com writes:
K7NV did a computational study some years ago to compare pier pin versus
fixed base construction, and found some circumstances, IIRC, where the fixed
base would cause failure in the first section at a lower wind speed than if an
ideal pier pin were used.
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However,one overlooked advantage of having a stick in the ground opposed to
pier pin is the ability to drop the guys at any time (or having them fail from
an accident like heavy machinery snapping them as happened once on one of my
towers) and still have a standing tower.
Guys with modest height Rohn 45 and 55 have the advantage of just hauling an
antenna up the side of the tower to the top after dropping the guys and then
replacing them before anyone goes back up the tower to put the antenna in its
final spot....can't be done with a pier pin! It sure beats assembling an
antenna on the tower or having to rig a tram.
I have, as a one man operation, raised a 40 meter KLM 4 el Yagi in this
fashion to 90 feet many times. Of course, you can't be stupid about it.
Raising
it on a day Ernesto is expected is a no-no.
Bill K4XS
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