On Mon, 4 Aug 1997, David & Barbara Leeson wrote:
> Some of the sizes can forced over a connector, but it's better to put
> the grip on first, then the connector. I put a black (UV resistant)
> ty-wrap at the bottom to keep the tensions on. I've noticed that
I noticed that Andrew is now selling Kellum-type grips for Heliax cables
to suspend cable inside monopoles. They include the grip and a
stainless-steel tiewrap; I disagree with this big-time (the tie-wrap,
that is...).
My employer used to use stainless-steel tiewraps to hang cable. The
trouble is, you either have the tie too loose (and the sharp edge of
the tiewrap cuts the jacket over time) or too tight (and you crush the
cable). We now usually use cushions from Microflect (but they are
expensive).
BTW, on a recent project I had one tower manufacturer (Microflect)
recommend hanging heliaxes inside monopole towers using a grip at the
top. Their answer was "that's the way everyone does it". Well, I was
worried that Andrew, the cable manufacturer, wouldn't honor a warranty if
the cables were installed that way. I phoned Andrew and asked if they
had a written warning against hanging cables from one end for years at a
time.
The person I spoke to said "no, but we also don't have a written warning
against setting your heliax on fire either. There are some things that
are just common sense". (Wonder if he ever read an April QST?) Anyway I
pushed him for an answer in writing, and he put me on hold while he asked
the Andrew monopole division how THEY supported cables inside a mast.
He returned a few minutes later and said THEY supported cables from one
end with a grip inside the mast...just as Microflect recommended and
Andrew cable said was a no-no! Now Andrew is coming out with a grip of
their own...
Makes you wonder why they have all the other cable hanging items in the
book! The Kellum Grip...the "ginszu knife of cable support"!
73, Jim N6IG
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