I have been using short pieces of FSJ4 outdoors for years outdoors as a
jumper from much larger Heliax to antenna relays, etc. It is perfectly
suited for outdoor use and I see no reason why it would be more prone to
water ingress than any other Heliax. I would not use it around antenna
rotators as it is not that flexible and for long runs like the one you're
referring to LDF4 is probably a better and more inexpensive choice on the
surplus market. He probably has some connector problems. I believe
professionals use this FSJ4 outdoors all the time for jumpers and seal the
connectors with tape, butyl rubber and more tape.
John KK9A
To: <towertalk@contesting.com>
Subject: [TowerTalk] Andrew FSJ4-50 issues
From: "Jim Thomson" <jim.thom@telus.net>
Date: Sat, 16 Jan 2016 05:57:06 -0800
A buddy is having issues with his Andrew FSJ4-50 flexible coax. It's
being
used on a rotating tower.
He used FSJ4-50 from each yagi to the tower, then spliced ( via a male to
female 7-16 din) into
more FSJ4-50 heading down the tower. At the bottom of the rotating tower
is
the remote switch box.
On the 40m coax connector, at the remote switch box, there is water coming
out
of it ! The splice
was encased in heat shrink, with the glue glop inside. Also at each
balun.
We think the cable coming down the tower is toast. Is this FSJ4-50
intended
to be used outdoors ??
I looked at some old postings from 2006, and it appears that FSJ4-50 was to
be
used indoors only, for
jumpers etc. The other postings indicated it did not have any UV protection
on
the outer jacket.
I THINK I also read somewhere a long time ago that FSJ4-50 was prone to
water
ingress.
Does anybody know the real story on this stuff ? It can be replaced with
the
rigid andrew 1/2
inch regular heliax. It doesn't have to flex for this application....on a
rotating tower. At the base
of the tower, where the remote switch box is, there is a single, flexible
piece
of coax, used
for rotating the tower, like 213-U...then the 213-U is spliced into more
(normal rigid) 1/2 inch heliax,
and off to the shack area.
The concern here is... if FSJ4-50 is pone to water ingress, then he may well
be
in for more problems,
since all the coax runs down the tower are also FSJ4-50
Thanks in advance.... Jim VE7RF
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