I used option 2. I did not want the bundle to freeze down on the winter. I
encased the coax (9913F) in 1/2 inch heater hose at the arms to keep it
from kinking. And I staggered the arms over an angle so they couldn't catch
Jim Rhodes K0XU
Sent from my Droid Razr Maxx
On Nov 19, 2012 10:59 AM, "Grant Saviers" <email@example.com> wrote:
> Chris, KF7P makes arms with free sliding loops and also with hoops that
> the coax is tied to.
> The hoop design keeps the coax from kinking, keeps it on the tower,
> although enough slack is needed to still have an "upward" exit loop for
> when the tower is fully extended. I'd guess about 5' more coax is needed
> for every hoop vs loop standoff, if that loss is a concern.
> My cable bundle per tower (2x HDX589) was 3 x 9913F7 or Buryflex (much
> better stuff than 9913) plus rotator plus ethernet plus a 4 conductor
> control cable for tower mounted gadgets. The hoop design worked fine on
> one tower, but it wasn't easy for me to get the loops the right length
> between hoops. On the other tower, they just wouldn't work - kept getting
> snagged going up. Bundled cables seem to get a mind of their own about
> twist and residual bends. Mine were carefully pulled without any twist,
> then 3M taped every 18" or so. One tower's bundle was well behaved on the
> hoops, the other wasn't. One of the rotator cables was noticeably stiffer
> and with different coax that made the difference, I think. Another risk
> with hoops might be trying to lower the tower when the wind is blowing the
> coax around and it snags.
> Steve K7LXC took one look at the hoops and said "that's not going to
> work." Oh well, many trials with hoops had me talking to Chris and he made
> it right by exchanging the hoops for loops and they work great on both
> towers. I measured the offsets and extensions for the 589 as he had not
> made them for that tower in its current UST revision. Now they are a thing
> of beauty :-) .
> Pre twisting the bundle is an interesting idea to keep it in a container.
> I chose to use the mariners trick to flake heavy lines into a figure 8 as
> the tower descends. Each half twist reverses the prior half twist. One
> tower's concrete base grew large enough (another story) that the coax
> flakes on it and the other is surrounded by grass so it's not messy.
> Having a clean work area around the base is a really good idea - gravel,
> grass, pavers, etc. It is small cost/effort considering what is otherwise
> invested. Of course, I need to attend 100% the tower lowering, but I
> wouldn't ever think of lowering these towers remotely.
> Grant K71W
> On 11/19/2012 7:36 AM, Dick Dievendorff wrote:
>> At my last installations I chose option 1), and as I lowered the tower, I
>> guided the coax bundle into a circle on the ground. I added an angular
>> support to the topmost stand-off arm so that the weight of the whole
>> was better supported. I had 6 RG-213 coax cables, rotator, and a control
>> line for 80/75 relays on a dipole. The coax bundle was taped together
>> every two feet.
>> I saw a really neat installation at N6EK a few years back. Bob had a
>> washtub inverted on the ground. He had applied the right twists to the
>> cable so that it coiled rather naturally around the washtub all by itself
>> when the tower was lowered.
>> 73 de Dick, K6KR
>> -----Original Message-----
>> From: TowerTalk
>> On Behalf Of Larry
>> Sent: Monday, November 19, 2012 7:22 AM
>> To: firstname.lastname@example.org
>> Subject: [TowerTalk] How to deal with Coax on a Crankup Tower
>> Slowly, but surely, my tower project is making progress.
>> Got a lot in place or will shortly finish. Tower is mounted, grounding in
>> place, A/C power. It's getting real.
>> Now it is time to consider a homely little problem I have given no
>> significant thought to: Routing the coax up and down the tower as I crank
>> it up and down.
>> The tower's manual gives me no explanation on the coax stand-off arms that
>> come with it. It states helpfully that when I install them correctly,
>> will line up top to bottom. That was OK and expected. What is not
>> is exactly how, exactly, the coax ought to "travel" on the tower.
>> The standoff arms themselves seem to consist of an open loop that has room
>> for several coax to be in them. Good as far as it goes. But, it seems to
>> admit to two designs.
>> 1. Let the coax freely fall the whole 60 to 70 feet (this will vary based
>> on the three coaxes I will be running up the tower). The cable would be
>> "guided" by the standoffs, at least as far as the tower, proper goes.
>> 2. Fasten, in some manner, the coax to each stand off. There would be a
>> modest amount of slack when the tower was fully extended and more when it
>> was not.
>> At the W0IBM club station, which had basically the same tower, the second
>> option was chosen. It would be using 9913 F for my runs, so that the coax
>> would be largely in the air. As at W0IBM, it would simply form a graceful
>> and natural loop between each standoff when the coax descended (I'm pretty
>> sure the W0IBM tower used RG8 or something flexible -- no 9913F back
>> I could also attach the DC control wires for the rotor to the coax as well
>> (I presume).
>> If I chose the first option, which the design of the stand offs kind of
>> superficially invites, the coax would have to "pool" at the bottom of the
>> tower, and it would do so in a place that looks rather unfriendly for the
>> It seems "obvious" to me that the second should be chosen, and yet I don't
>> remember seeing much discussion about this. Or, details about how to
>> Assuming the W0IBM solution is the right one (it would also help frustrate
>> the local copper thieves, too), how do I attach the coax to each stand off
>> and do so in a way that helps fight off the Arizona sun, which does things
>> like bleach "caution" tape in about a month's time?
>> Larry Wo0Z
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