Jim,
I had good luck using a 10" long eyebolt through the mast about 2 feet ABOVE
the boom. I supported the coax loop (ran the coax thru the eye) from the
eyebolt and adjusted the loop length until it maintained good clearance
throughout the rotation. The coax is dressed from the boom UP the mast, then
out and through the eyebolt, then loops down past the boom and into kellum
grips at the tower top. In my case with a single beam, I didn't mind
drilling through the mast above the boom. In your case, with a stack, not
wanting to compromise the mast strength, you could try a clamp with an
outrigger arm to support the coax loop. At extremes of rotation of the Yaesu
rotor, the boom will catch the lower bight of coax and carry it around 10-20
degrees; leave enough slack so that's not a problem. Sounds more complicated
than it is. Just don't be bound by the convention of always having your coax
departing downward from the boom!
Chuck, N4NM
----- Original Message -----
From: Jim, K0MHC Austin, TX <froemke@ibm.net>
To: <towertalk@contesting.com>; vhf <vhf@w6yx.stanford.edu>
Sent: Wednesday, May 12, 1999 1:36 PM
Subject: [TowerTalk] ROUTING CABLES AT THE TOP OF ROHN 25AG4 TOP SECTION
>
> Any advice on the problem of routing cables above the top of a Rohn
> 25AG4 top section when the first antenna boom (of the stack) is within
> 12 inches above the flat top tower section?
SNIP>>
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