[TowerTalk] PL-259 Going Open?

[Bill MacLane]

Starting with 9913; it is not waterproof with a PL-259
Second PL259 connectors are not waterproof.

What you may be experiencing is fretting.  It is oxidizing at the point of contact whether it be solder or point contact of a mating face of a connector.  Tin-lead is very suseptible to fretting.  

There are connectors made specifically for 9913 available from the RF Connection.  Also N connectors are water tight to a degree.

Even with N connectors I heatshrink over them with waterproof heatshrink, especially if they will lay in water or be on a tower.  I like climbing, but I do not like to redo my work whether on a broadcast tower, microwave STL or my amateur gear (tower pending).

The other thing with solder exposed to the elements (like water and moisture) is it will crack.  Thus leading to an open or very high resistance contact.  This has been experienced where folks solder copper conductors and they get burried. The reason a good ground plane and radials are brazed at connection points.

Hope this helps.  I'm sure others have even more suggestions.

73,
Bill
AI4WM


--- On Sat, 12/20/08, Kim Elmore <cw_de_n5op at sbcglobal.net> wrote:

> From: Kim Elmore <cw_de_n5op at sbcglobal.net>
> Subject: [TowerTalk] PL-259 Going Open?
> To: towertalk at contesting.com
> Date: Saturday, December 20, 2008, 8:43 PM
> 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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