In a message dated 97-05-13 13:02:16 EDT, kg5u@hal-pc.org (Dale Martin)
writes:
> Well, I thought I had saved it, but looking through my folders,
> I find I did not save a particularly interesting and informative
> note on how to properly seal the coaxial cable connector joint
> at an antenna.
> The antenna is a G7-144 with an N-type connector.
> Do I need to seal it? I say no.
As far as an N-type connector, it (unlike a PL-259) has a rubber gasket
and is designed to be mostly waterproof (unlike a PL-259).
By using proven weatherproofing techniques and materials, you'll be
GUARANTEEING that the sucker won't leak. It's your 'belt and suspenders'
approach. BTW, you'll never see a commercial joint that ISN'T totally
weatherproofed.
First thing you do is use a pair of pliers to seat the connector - hand
tight isn't good enough. You'll need 2 pair for PL-259s and a barrel
connector.
Next, throw away your CoaxSeal. It is not a commercial material and
anyone that's used it probably realizes what junk it is. Apply a butyl rubber
vapor wrap material (NOT CoaxSeal, okay?) over the joint. Commercial products
will peel off when sliced open with a razor knife. (Another way of doing it
is applying tape over the joint first and then adding the vapor wrap. Either
way works but some TowerTalkians that I respect put the vapor wrap on first.)
Now throw your cheap electrical tape away. Three rolls for 99 cents from
your Ace hardware store won't cut it. Use either Scotch 33 or 88 (for a
number of reasons) and put at least 2 layers of tape around the vapor wrap.
Important Tip: DO NOT stretch the tape to separate it. Tear the tape
carefully or cut with dikes, razor knife, etc. Now let the tape relax before
you apply the end. When you pull it and apply it under tension is when it
comes loose and 'flags' in the wind.
Next Important Tip: apply the final wrap in a upward direction (if the
run isn't horizontal). This is like the shingles on your roof. If the tape
goes down, the tape won't overlap and the water coming down the coax will run
right into your joint.
> One of the other going up with me is mentioning some sort of
> liquid tape. I have not seen it referenced at all on the tower reflector
> (probably for good reason). Anyone use it? Any negative comments
The final step is to coat the electrical tape with some sort of
protective coating. Of course 3M recommends their ScotchKote product. Liquid
Electrical Tape has been covered and is a james dandy product - UV resistant
and everything. Another technique is to spray the joint with spray clear
urethane; it's pretty effective too.
Follow these steps religiously and you'll NEVER have a weatherproofing
connector problem.
And, coincidentally, TOWER TECH carries all of these products - except
the CoaxSeal!
73, Steve K7LXC
TOWER TECH -- professional tower supplies for amateurs
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