Well, sure, if you've got the dough for the stainless brackets and all, go
for it!
Also, I do agree and do use the stainless net grips to hoist and secure
hardlines at the top of the tower. However, even the black tie wraps will
not last for many years unless you tape them all. If you use this THHN wire
or something else with a tough insulation, it will last a lot longer and
it's pretty cheap. I cant imagine it being an RF problem as long as the
insulation is intact....it's wrapping around a tower leg and a grounded,
shielded cable and it's length is very short. Well maybe, I wouldn't use it
in close proximity to VHF and up antennas, but on HF it should be no
problem.
Ty K3MM
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Daron J. Wilson
Sent: Saturday, December 02, 2006 4:19 PM
To: 'Hector Garcia XE2K'
Cc: towertalk@contesting.com; wc1m@msn.com
Subject: Re: [TowerTalk] Cable ties, tape or both?
: Re: [TowerTalk] Cable ties, tape or both?
>
> If you remplace a cable or add another you can use
> again the same wire , not the same with ties or tape.
>
> the wire is thes option
> the quality of how looks depend of you. but you can do
> a professional job very cheap and secure.
I disagree. I've spent days cleaning up a couple commercial installations
where this type of securing was used. First let me say I prefer the proper
method of securing feed lines (rubber grommets or doughnuts, stainless steel
clamps for the particular feed line, black nylon clamp sets made for this
purpose, etc). However, a short piece of Rohn 25 in the back yard with a
couple pieces of coax on it may not warrant that. None the less, it does
warrant a quality installation IMHO.
As far as reuse, sure, wire ties are generally a one time deal. In the few
installations where I have to wire tie to a support along with other folks,
my runs are all secured together but with ties that I threaded under the
other feed lines on the same support. Sure it is more work, but when
someone goes up to drop their antenna and feed line and cut their wireties
off, the don't cut mine loose.
Why not pieces of copper wire?
1. They resonate. They ARE resonate at some frequency or variety of
frequencies. Adding short pieces of metal (not rounded) with coils in them
to an RF environment is asking for trouble.
2. Tightening. Since the product you are tightening with your pliers when
you twist the wire together is not visible you have no way of knowing how
much stress you are putting on the copper wire. You may be twisting to what
you think is just right but then stressing the strength member to almost
breaking. You can't tell, you simply don't know how well that will hold the
stress.
3. Metallic contact. Sure, the wire is insulated. Until you over tighten
it by twisting and it vibrates on the rough galvanized metal tower until it
rubs through the insulation and now we have copper reacting with the
galvanizing. Add water and you won't have to wait long for some noise.
Personally, I think the feed line should be supported with a hoisting grip
if there is any weight to be concerned with, then secured to the structure
with manufacturer approved hardware. Use stainless or galvanized hardware
on the galvanized tower. If I'm just securing to a little Rohn 25 or
something, generally, the feed line gets a half dozen tight wraps near the
top with 2" quality electrical tape just as a safety. Then, black UV rated
wire ties (1/4" or 3/8" wide depending on the feed line) secure the feed
line to the tower at regular intervals. Be sure to cut the wire ties with
flush cut cutters, it sucks to get your hands sliced up on that sharp little
piece that sticks out if they are cut with regular sidecutters.
Your mileage may vary....good luck.
N7HQR Daron
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|