If I look at a cross section of 9913 and RG213 I see the same thing - space.
I grant you that the space is a lot bigger with the 9913. However, what is
there in RG-213 to prevent the same moisture from getting to the shield on
RG-213? The braid on 213 isn't sealed or in a vacuum. If you have moisture
ingression in 213, the shield discolors. Doesn't the same rule apply to both
types of cable - seal it well and moisture won't get in?
I have seen both 9913 and 213 that was discolored due to moisture and I have
seen both look like new after several years. It would seem the water issue
is a problem for either cable.
Here in New York it gets hot, cold, rainy and dry too.
Over the years I have used nothing but 3M super 33+ with great success
keeping the connectors and coax nice and shiny.
73,
Tony
-----Original Message-----
From: owner-towertalk@contesting.com
[mailto:owner-towertalk@contesting.com]On Behalf Of Tom Rauch
Sent: Wednesday, December 19, 2001 11:38
To: pwomble1@tampabay.rr.com; towertalk@contesting.com; K7LXC@aol.com
Subject: Re: [TowerTalk] 9913 Reliability
> > 9913 is not bad cable...you just have to be extra careful sealing
> > connectors & making sure there are no nicks or cuts anywhere to let
> > H2O in.
>
> I would hazard a guess that most, if not all, 9913 moisture
> problems are
> due to poor weatherproofing. Check the TT archives at
> www.contesting.com for some good write-ups on the RIGHT way to do it.
You would NEVER get away with "sealing" 9913 in GA and
keeping water out. It probably is fine in Arizona, however.
The only way I can think of the be safe in a humid climate is to
flood the first few inches of cable with RTV after filling it with dry air.
Problems are proportional to length and the "drop" in the cable, as
well as local climate. If you have a flat run that is short, even if it is
a mild leaker, you likely won't find a pool of water no matter how
hard you look.
If you have a 160 foot vertical drop, water will pool at the bottom no
matter how you seal the stuff, short of plugging the ends with a few
inches of RTV after purging it with dry air!
Hollow cables without dry air pressure are a dumb idea. The loss
decrease is very minor over foam, and no matter what you do it is
unlikely you can seal a cable so good with air so dry you never
have a problem, desert areas excluded.
73, Tom W8JI
W8JI@contesting.com
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