Hi Steve: Well - you have the correct desription. The Kellums
are hoisting grips. They are a great way to pull the transline
up the tower. But - proper dressing requires the cable to be supported
every few feet.
By the way - I've been up a few towers myself and have never seen
a "Professionally" built installation that doesn't use the hangers.
Now-a-days there are a lot of guys putting up steel, and from what I hear
from my friends, some are pretty shabby, especially those who got
into the game to take advantage of the PCS buildup.
I would venture a guess that hardline will migrate when suspended
only a couple of times at 150'. Maybe ham towers that replace the
equipment every few years would not show the migration, but
I have to believe over a long period, the weight of the coax on the
one or two support points would be hard on the cable.
By the way Steve, I don't have the catalog here at home - but
the coax hanger kits are about 25 Bucks for a package.
and each package has many in it!
I'll have to check the catalog tomorrow and get back with you
with a price. But certainly not 25 bucks each. I use them
by the hundreds.
Again - transmission line is not well protected if supported
every 50' or so. Too much stress on the cable. I'd rather use
tye-wraps and you know how little I think of that approach.
73 de KL7HF
----------
From: K7LXC[SMTP:K7LXC@aol.com]
Sent: Monday, January 19, 1998 1:30 AM
To: seay@alaska.net; tbernie@shore.net; towertalk@contesting.com
Subject: Re: [TowerTalk] Supporting Long Hardline Runs
In a message dated 98-01-18 16:20:14 EST, seay@alaska.net writes:
> The proper way is to buy the standard coaxial cable hangers
> that can be bought from most of the mfg's such as Andrews,
> DB Products, etc.
I'm talking hoisting grips and you're talking hangers.
I've installed miles of commercial cables and always used hoisting grips.
For ham applications, I don't see any problem with using Kellem grips - at
least you can get them locally. BTW, the Andrew price for a hoisting grip for
1" cable is $51.00. You can get the Kellem grip for less than $10.00.
The Kellem grips primary purpose is for pulling cables through electrical
conduit. It's a horizontal pull as opposed to a vertical one. I don't see any
practical difference for hoisting and attaching the grip to the tower. It'll
take the weight and then you can use some kind of cable-to-tower attachment
method.
>
> They are a small stainless clamp of the proper size with a
> rubber inner boot. The clamp goes around the cable and also
> attaches to the tower with a round member clamp, similar to
> a hose clamp. Use one every 5 feet or so and it will last forever.
>
If you're referring to the 'insulated hanger', p/n 11662-2. They are
$23.50 each.
There are a number of ways of attaching the cable to the tower including
special hangers. For Heliax provided by Motorola, you are given a bundle of
#14 THHN wire to twist around the cable where it attaches to the tower. Not
very sophisticated but it works FB. Other methods including tie wraps, tape,
etc. are also useful.
> I've seen the statement that the Kellums are used on all
> professional towers. Guess I haven't seen any of them, because
> all commercial quality towers use the cable clamps.
A hoisting grip, anyway.
> In terms od cost, it will probably run $25.00 for enough clamps
> to hang 150' of hardline.
That's good for one clamp anyway.
While this has been an apples and oranges discussion between hoisting
grips and hangers, both devices should be used for proper cable installation.
This becomes more important as the cables get bigger than RG-8 as the dead
weight of the 150 feet of 1 inch cable under discussion can weigh one-pound-
per-foot or more.
73, Steve K7LXC
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