[TowerTalk] Andrew FSJ4-50 issues

Jim Thomson jim.thom at telus.net
Sat Jan 16 08:57:06 EST 2016


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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