In a message dated 7/19/2007 1:06:42 A.M. Pacific Daylight Time,
wwdxc@yahoogroups.com writes:
> I forgot to mention, also, that the use of barrel
connectors is discouraged, particularly in outdoor
runs. Somehow corrosion always seems to occur in these
connectors, causing the swr (and losses) to rise.
I think the gist of this thread is weatherproofing. I've installed
dozens (hundreds?) of barrel connector and other coax joints over the years
and don't know of any that've failed. Most amateurs make one or more mistakes
when weatherproofing coax joints.
First, use 3M 33 or 88 tape. The 3 for a buck stuff from the
hardware store won't cut it.
Next, use 2 pairs of pliers to seat the connectors to the barrel
connector. I'm not talking about deforming the PL259 - it's just that finger
tight is not enough.
Wrap 2-3 wraps of tape over the joint. Use a 50% overlap. Apply
vapor wrap (butyl rubber - there are a number of variations) over the joint.
Wrap
2 more layers of tape over the vapor wrap. If the coax runs vertically, the
last wrap should go up. That'll make the water run off like shingles on a
roof. Wrapped the other way and you've got a perfect duct for the water to get
into the connection.
Jim, you said you used these materials but maybe there was a step
you missed or something. Following the above scenario will give you a
bombproof
joint. Even leaving off the vapor wrap will still result in a reliable
weatherproof connection. Some commercial installers spray the finished joint
with
clear Krylon spray paint which is more belt-and-suspenders approach.
ScotchKote has been used in the past but it's really for buried connections
and will
dry up and flake off when used in an outdoor application like this.
Cheers & GL,
Steve K7LXC
TOWER TECH -
Professional tower services for hams
Cell: 206-890-4188
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