On 10/3/2011 7:40 PM, Guy wrote:
> Has anybody used this as coax connector weatherproofing solution? See
> http://www.radioworks.com/ccoaxseal.html
I take it you are asking about "STUFF" and not "coax seal"?
Both Scotch and MMM make a self sealing "rubber" tape with mastic. The
stuff bonds to itself.
They also make a putty like substance that appears to be the same as
"coax seal" such as GE 8880 High Voltage putty.
They all work pretty much the same. As for "STUFF" I'd much prefer to
use Dow Corning's DC-4 and DC-5 "Dielectric" compounds which were
designed for high voltages at high altitudes. When they do break down,
the result is still an insulator. DC-4 was originally used to
waterproof and seal spark plug boots on B-17's to prevent arcing at high
altitudes.
Thing is a 5 ounce tube is $16.45 from Aircraft Spruce
http://www.aircraftspruce.com/catalog/cspages/dc4.php
A word of warning about flooding connectors which they are doing with
"STUFF". It and several other compounds work fine for sealing/flooding
connectors *BUT* and that is a serious BUT, it is not a good idea to
flood all connectors in a coax run. Flood the one at the antenna to
prevent moisture entering the coax, but remember that coax is going to
breathe. A coax run with several connectors in the run that are sealed
will under go some pretty drastic pressure changes internally with
temperature changes. Up here this time of year the coax can go from
freezing at night to well over a 100 degrees on a sunshiny day. Coax
out in the sun can feel quite warm on a pretty cold day. The pressure
change is in psi, not inches of water. There are few tapes and seals
that can withstand that differential. Every coax connector in the line
then becomes a potential spot for moisture ingress. IF on the other
hand the antenna end (or top) connector is sealed and flooded while the
rest of the connectors are simply weather proofed so the coax can
breathe naturally along its length, the pressure between the outside and
interior of the coax will at most be a couple inches of water pressure.
However a coax run that "breathes" into a moist basement is likely to
breath in moisture that will condense. "Generally" most coax ends in a
heated room rather than a moist basement. With 10 or 15 feet of coax in
the house where it will stay warm, it is unlikely any humidity breathed
into the coax will condense. It'll just breath back out into the room
the next time the coax warms up outside.
Most often we never notice as the temperature may not swing that much or
the basement may not be that humid, of course part of it may be due to
not very many hams actually flood connectors.
73
Roger (K8RI)
>
> Thanks in advance, Guy
>
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