I discovered the clamping system on the Pro.Sis.Tel left something to be
desired:
A, It is NOT sheet metal, it is hardened steel, which is curved to fit
the mast.
B. This "collar" is welded to horizontal steel which bolts to the top of
the rotor
in 2 parts, when bolted making a clamp
C. The installation guys bottomed the mast when the antenna was installed
D. The weld bead between the collar and the horizontal bolting part makes
a smaller diameter than the "collar"
Result is the bolts joining the collar were not all tight, bottom and
top only :
Repair: climb the tower with chisel and socket wrench and box wrench.
Loosen the collar, jam the chisel under the mast raising it above the weld
bead about 3/8".
Tighten all bolts. Having battery operated drill to run a #8 bolt
through the assembly,
making certain there is no thread in the part that contacts the mast.
Has been up 8 years, mast to beam mount loosened once, but the rotor has
held
all this time.
Using a big Optibeam (36 foot boom, 22 elements).
73!
ed K0KL
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