My blood pressure can not take another citation of the advice to wrap your
coax plugs with any kind of plastic electrical tape for water sealing
out-doors (again in Aug. QST ant. article by "ed").
I have wrapped and unwrapped exterior coax fittings for 47 years, in cold
weather and hot, wet and dry. No brand of plastic electric tape will "seal"
against water incursion. I don't know why, but single, double, and triple
wraps don't matter--mosture still gets in. And, the worst thing u can do
with tape is to stretch-pull the last few inches prior to sticking the last
end down. The tape will eventually withdraw and become un-stuck for several
inches, at least. That matter is made worse if it is stretched to breaking
as a way of "cutting" and creating an end of the tape. And also worse if
human fingers hold the end, corrupting the sticky material and lowering its
holding power (but how else u gonna hold it?). Even Scotch 33 or its brand
brothers will curl and become brittle in high heat condx in a few years.
Cold shrinks it. Tape is just not the solution.
And PLEASE do not follow Cushcraft's old instructions to squirt silicone
sealant (which they sometimes supply in the new antenna box or with their
Coax Boots). I have poured a few drops of water out of exterior coax
fittings sealed "the Cushcraft way" after three years in the air.
How to do it?
1. Make one wrap of good plastic electrical tape, do not stretch pull it.
Then, apply Coax-Seal over the tape. Lightly wet ur fingers if the CoaxSeal
sticks to fingers. Mash the stuff all around the fitting. Do not put tape
over the CoaxSeal... that will push the Seal around and ruin the seal. The
under layer of tape is only for keeping the Coax Seal easy to remove from
the shiny coax plugs. I have a junk coax/connector/coax fitting so
installed lying in the open on a junk pile here in Fla. Looked like the day
I installed it 23 years ago.
1A. Alternative is to use the hugely expensive ($3. ea.) Cushcraft Vinyll
Coax Boots (part number VB5) and then Coax Seal over those. These Boots are
difficult to push down onto RG-8, and trimming the small hole to fit RG-8 is
very difficult to get exact. Coax Seal at either end of the Boot is
necessary.
2. Alternative is to use some of the shrink fit plastic tubing that has
heat-activated shrink AND heat-sealing gunk inside. Very quick install with
heat gun. Leave generous overlap. This stuff is new to me and I have no
long term tests on it. Report later.
To a good tight seal..... 73
Charles Harpole
[EMAIL PROTECTED]
Subscribe/unsubscribe, feedback, FAQ, problems
http://njdxa.org/dx-chat
To post a message, DX related items only, [email protected]
This is the DX-CHAT reflector sponsored by the NJDXA
http://njdxa.org
