feedline strain-relief

[Glen Zook]

You need to run some sort of "messenger" cable to
prevent the coax from actually stretching under its
own weight.  150 feet is way too long to expect
RG213/U cable to self support.  In fact, with a run
that long the cable is most likely going to "sag"
within a few feet of the ground if not actually making
it to the ground.  The force of trying to keep it
tight is going to cause the cable to either start to
stretch (which will change the impedance among other
things) and may even eventually break under the
strain.

If the center of the antenna is only 20 feet above
ground (which is going to make a "cloud warmer" type
of antenna!), I would put some type of mast at the
feed point, run the cable down the mast, and then bury
the cable under the ground.  A wooden mast or else a
metal mast with a short insulator would work fine.

Glen, K9STH


--- paul hendershott <pjhender2002 at YAHOO.COM> wrote:

I am running about 150' of RG-213 feed-line out to a
new light-weight antenna. The run of wire is suspended
up about 20 feet. My problem is that the feed-line
becomes quite heavy with this large span and I was
trying to think of ways to handle the strain at both
the antenna end and the end going into the attic from
outside.


=====
Glen, K9STH

Web sites

http://home.comcast.net/~k9sth
http://home.comcast.net/~zcomco




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