[TowerTalk] PL-259 Going Open?

john at kk9a.com john at kk9a.com
Sun Dec 21 11:33:55 EST 2008


PL-259s are not water resistant and they should be properly sealed it 
outside.  Also Belden 9913 can easily fill with water.  Since this joint has 
been exposed to water I think you should replace the coax as well as the 
connectors, perhaps with something less sensitive to moisture such as Belden 
8267.   Switching to N connectors may introduce other problems.  I have used 
them with excellent results with Belden 8267 and various sizes of Andrew 
Heliax but others have had the coax pull the center pin out of the connector 
in cold weather, creating an open.

John KK9A


To: towertalk at contesting.com
Subject: [TowerTalk] PL-259 Going Open?
From: Kim Elmore
Date: Sat, 20 Dec 2008 19:43:21 -0600


I'm not sure Towertalk is the right forum, but here goes:

I'm using PL-259s outside to connect transmission lines (Belden 9913)
that run up the tower to my antennas to the underground lines that
run to the shack.  Obviously, the PL-259s are connected through a
barrel connector (which has a number designation I've forgotten).
Everything is Amphenol and I've soldered more PL-250s than I can
count, all with an American Beauty 100 W iron.

Twice I have experienced one of the PL-259s becoming open. These have
been outside for about two years and I live in Oklahoma, so while we
see about 35" per yrar of rain, it tends to come in good sized
amounts with extended dry periods in between. Disconnecting and
reconnection doesn't affect the problem and bending around the
transmission line has no effect: I have to actually re-solder the 
connectors.

This has happened only to my HF transmission lines: there's no
problem (so far) with my VHF/UHF lines. There is no warning and no
prior symptoms. Using a tuner, I can sometimes of feed a little power
to the system and see things change with 100 W power applied but the
match is unstable and nothing ever becomes normal. The connectors are
exposed and are not sealed with any sort of tape or flooded shrink
tubing. When I look at them, the solder still looks good, but to
reestablish connectivity I must re-solder them.

I'm currently planning to replace connectors exposed to weather with
N-connectors, but I've never seen this before, even though I've had
connectors outside before that have lasted for many years with no
problems. Has anybody else experienced this?

Kim Elmore, N5OP 



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