I took a bit different approach for my 7 KX0G rings (motor is on the
rotating ring). My objective was the coax and motor power cable would
never touch the tower. I made a 30" long swing arm, mounted below the
ring, which follows the ring via the cable pull thru its allowed 300+
deg rotation. A 8" fixed arm support is on the ring to further insure
the cables are well away from the Rohn 65 and ring and to never get an
"over-center" cable path. The service loop hangs below both arms. I use
Buryflex coax and 16/3 for the 180 VDC motors. There is a small cable
service loop at the swing arm pivot to accommodate its motion.
This might work with the swing arm above the ring and the cables tied
out on the boom a bit. I don't think using the boom guy mast as the
attach point would meet my goal of cables not touching the tower.
I also fabricated limit switches on the tower with IP65 rated
microswitches. Aiming due South isn't of much use here, so the
sacrifice of a bit of travel is ok.
Grant KZ1W
Redmond, WA
All has worked well and checked out ok when inspected, the last 4 years.
On 3/27/2019 9:23 AM, Dick Green WC1M wrote:
I have coax and SteppIR control cables, taped together, that loop above the
boom because all three of my rings sit about a foot above a guy bracket. The
guys and brackets could interfere with a loop below the rings.
There are some photos of the tower on my website, www.wc1m.com, which shows why
below the rings won't work for my setup, but the photos can no longer be
enlarged and it's hard to see the loops (and not all that easy to see them in
the hi-res versions.) The site is hosted by the ISP I ditched years ago and I
haven't done any maintenance since. Need to move the whole thing to a new host.
One of the huge number of very time-consuming low-priority projects on my list.
From memory (still lots of snow on the ground here), the coax is attached to
the tower about 5 feet above the ring, drops straight down and loops back up to
the top of the boom truss support, which is a 3-foot piece of galvanized pipe
offset from the ring's boom cradle using a custom mounting plate made from roof
truss plates. The key is that the boom and pipe are mounted away from the tower
face, leaving enough room for a loop. From the top of the truss support, the
coax goes straight down the pipe, to which it's taped, then snakes out along
the boom to the feed point. Pretty sure I used Bury-Flex for the coax, which is
quite flexible, but I might have used RG-213 because the runs from the stack
match are only about 35 feet or so.
73, Dick WC1M
-----Original Message-----
From: Tim Duffy <k3lr@k3lr.com>
Sent: Sunday, March 24, 2019 3:26 PM
To: 'StellarCAT' <rxdesign@ssvecnet.com>; 'tower' <towertalk@contesting.com>
Subject: Re: [TowerTalk] how to do coax on ring rotor?
HI Gary
Have the loop below the boom works very well here. You have to have a safe
climber in place for the installation and it check out 360 degrees while
someone in the shack (linked by radios) operates the control box. Take measures
to insure the coax can never get caught by the guy attachment hardware. The key
to this is coming off the boom about 3 feet away from the tower face.
73
Tim K3LR
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
StellarCAT
Sent: Sunday, March 24, 2019 1:56 PM
To: Tim Duffy; 'tower'
Subject: Re: [TowerTalk] how to do coax on ring rotor?
Thanks Tim ... as I wrote David direct - it was a "DUH!" moment when I read
his note - which was to use the truss support upright. I have been focusing too much on
the actual antenna and the coax along the boom .... thinking loops around the tower and
drapes etc.... I hadn't even considered the truss support. That should be pretty straight
forward.
I do have a guy right below, within 3', so I'm reluctant to let it hang down
directly from the boom .... although it looks like that is what you do Tim.
Gary
K9RX
-----Original Message-----
From: Tim Duffy
Sent: Sunday, March 24, 2019 12:27 PM
To: 'StellarCAT' ; 'tower'
Subject: RE: [TowerTalk] how to do coax on ring rotor?
Hello Gary:
You can go to my website and see lots of photos of coax with ring rotors.
There are 23 ring rotors here - so if you have questions after looking at
the photos and videos - please email me and I will help
http://www.k3lr.com look at contest photos and videos
73
Tim K3LR
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
StellarCAT
Sent: Sunday, March 24, 2019 12:00 PM
To: tower
Subject: [TowerTalk] how to do coax on ring rotor?
I’ve got two TIC ring rotors that are going up – hopefully this spring ...
they’ll have 2 7 element 10’s on them ... (yeah, I know, 10M’s).... and I’m
trying to figure out the best way to handle the coax coming off of the
antennas. Both going up from the ring as well as going down. I need up
because one of the rings will be mounted 4’ above a guy point so going down
isn’t likely to be a solution.
Anyone done this already and gone through the trials and tribulations of
getting it right?
You’re welcome to write direct to my ARRL email address or post here...
thanks – Gary, K9RX
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