I don't know if there is any magic here, but this worked for me for the
last 15 years. I have done this with both RG-213 and RG-8X.
I used Scotch 88 electrical tape to secure the coax to a tower leg near
the top. I don't know why that wouldn't work with your 220MM mast - you
could put a big plastic cable tie over one layer of tape and under
another, for sun protection. Then I led the cable over to the rotating
antenna mast and, with the antenna at mid-rotation, I wrapped 3 turns
loosely around the antenna mast. Finally I taped the feedline to the boom.
My Yaesu rotator turns a total of 450 degrees, but with this arrangement
the rotator loop is supported by the antenna mast, essentially just
loosening and tightening around the mast as the antenna turns. Our
climate is fairly benign, but after all these years of lots of sun and
temperatures from -15C to +35, the original tape still looks good
The other common approach is a single 180-degree loop in the vertical
plane, long enough so that it can wrap around the mast as the antenna
rotates without running out of length before the rotator stops. I prefer
the wrapping approach because it seems to me that it flexes the cable
less at any given place.
73, Pete N4ZR
The World Contest Station Database, at www.conteststations.com
The Reverse Beacon Network at http://reversebeacon.net, blog at
spots at telnet.reversebeacon.net, port 7000 and
arcluster.reversebeacon.net, port 7000
On 9/9/2012 9:29 PM, Frederick Mott wrote:
I installed 2 runs of 7/8 helix cable on the inside of my tower and I used
SS cable ties. Plastic ties (I don't know of any good UV protected plastic
ties) will rot away after a few years of sunlight. As far as your cable
length, add enough cable to make a loop between the tower and your antennas
so that the cables will not be stressed. Use your judgment or better yet
buy some good antenna and or tower books/publications from the ARRL.
From: Rick Kiessig [mailto:email@example.com]
Sent: Sunday, September 09, 2012 8:08 PM
Subject: [TowerTalk] Coax and cable loop at antenna
How do you figure out how much coax and control cable to put between your
rotator and the antenna?
How do you secure those cables on both the tower side and at the antenna?
What kind of coax do you use there? BuryFlex or something else?
I'm also looking for a good way to secure cables to the outside of the
tower. I'm not using a Rohn-style with multiple smaller support posts.
Instead, it's a single pole, 220mm in diameter. I'm reluctant to just use
long plastic cable ties. Is there a better approach?
73, Rick ZL2HAM
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