[Elecraft] Waterproofing coax connectors (Was: N Fittings)

[Vic Rosenthal]

I've tried different methods of waterproofing outdoor coax connectors for years, 
and here is my experience, for what it's worth:

1) Vinyl electrical tape by itself -- the cheap kinds unwrap themselves.  The 
expensive Scotch brand (and possibly others) will do a good job, but you need to 
follow their instructions, use the proper amount of tension, and do it carefully 
(sometimes hard to do while standing on a ladder, etc.).

2) Vinyl electrical tape plus "Liquid Electrical Tape" -- I have just recently 
started using this method, so I don't have long term experience.  But it seems 
to work well.  You use any kind of vinyl tape, even the cheap junk, and then 
coat it with the liquid tape product.  The liquid contains a solvent that 
softens the vinyl tape, and it seems to seal very well.  It is easy to remove by 
slitting it with a knife.  So far, no problems.

3) Coax Seal -- Does a good job and is easy to use.  I have had connections 
seald for years which have stayed dry.  A little hard to clean up when you take 
the connection apart.

4) Heat-shrink tubing -- Don't use it!!!!  Here in Fresno we have lots of 
sunlight.  Apparently the shrink tubing is attacked by UV, whereupon it splits, 
leaving you with no protection.  I know some commercially made cables come with 
it, and maybe there's a kind that's UV proof, but I don't trust it.

5) Cushcraft-type boots -- I had one of these split after a few years in the 
sun.  Again, there may be various types, but I don't trust them either.

6) Self-vulcanizing rubber tape -- I've never been able to apply it properly, 
but looks like it would work well (although I don't know how it would respond to 
UV).  Tends to want to stick to itself, etc.  Everything is harder when you are 
on a roof or tower.

Just a word about what happens when you DON'T waterproof your connectors:  water 
will corrode the joints in the connector, but worse, it will move into the coax 
braid by capillary action.  It will invade the entire piece of coax, corrode the 
braid, and render it very, very lossy.

-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco