[Top] [All Lists]

Open in coax

To: <>
Subject: Open in coax
From: (Del Seay)
Date: Tue, 15 Oct 1996 09:49:41 -0700
Chuck Brudtkuhl wrote:
> Mail*Link(r) SMTP               RE>>Open in coax
> Finally have to put my 2 cents worth here.   One cause of center conductor
> pull-back or "creep" is being overlooked and is well-known in the
> tele-communications industry where coaxial cables are used in central office
> environments to carry DS-3 signals.  It appears as though when long pulls of
> cable are made through potential tight situations, there is a small amount of
> "stretch" that occurs in the cable.  Over time (several months) as the cable
> "settles" it is not uncommon for the center conductor to retreat into the
> cable a small amount....just enough for an improperly installed BNC to have
> the center pin go high joint or open.  I could see the same scenario playing
> out when pulling a long vertical run (up the tower) and then securing the run
> for support down the tower.
> 73 de Chuck

Correct, Chuck - however, I think most of the center conductor retraction
is caused when the insulation is removed from the center conductor.
(On standard coax - not Heliax, etc.) The newer versions of coax cable
has a very hard insulation between inner and outer conductors. When you
remove it, tension on the innerconductor causes it to stretch out. Then,
after the tension is removed, it tends to migrate back to it's original
position. The old RG-8, 213, 214 etc. was much less likely to have this
In addition - quite often, factory splices (Yep, if you have a run of
a couple hundred feet - it is spliced) can cause the same effect.
See ya'  de KL7HF

FAQ on WWW:     
Administrative requests:
Sponsored by Akorn Access, Inc & KM9P

<Prev in Thread] Current Thread [Next in Thread>