I had some stuff which looks like gooey puddy that is a coaxial seal
specifically intended for weatherproofing various connections.  It is
something you just smear over the connection and it forms a water-proof
seal.

Another option is to buy some silicon dielectric lube which is used to seal
sparkplug wires, which you can get at an auto-parts supplier.  Finally, I
undetrstand Radio Shack has some Teflon tape which is intended for sealing
connections.  Haven't worked with that stuff, though.
Steve
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