On 10/6/2011 10:55 AM, K7LXC@aol.com wrote:
> In a message dated 10/5/2011 2:10:29 P.M. Pacific Daylight Time,
> TexasRF@aol.com writes:
>> Steve, the theory for using an inert filler is that the space inside
> the connector is filled, leaving no room for water. Valid? Who knows?!
As I mentioned, it also has hazards associated with it. If multiple
connectors, or both ends of a run are flooded the pressure differential
between the inside of the coax and outside can become considerably more
with changes in temperature. I think most of us have seen the
demonstration where a metal can is heated, capped, and then cooled with
atmospheric pressure crushing the metal can. If the cable is installed
on a nice sunshiny day with flooded connectors a similar pressure
differential can exist. If it is installed on a cold day, then the
pressure inside can get quite high on a hot day. Both conditions are
likely to blow out the flooding compound. The hazard with the first
condition is the cable ingesting humid air, or actual moisture.
It's normally recommended that only the end at the antenna be flooded.
I've done it that way and had no problems, but I prefer to just do a
good job of weather sealing the connectors. Most ham antennas need the
antenna connector sealed as well as they are a great place for water to
get in. I think it's probably more important up here in the North where
we have greater temperature cycles from day to night and week to week,
or season to season. OTOH the high desert has some pretty big
temperature excursions from day to night.
> Well, yes - that's the theory. And I'm sure it works. But it's not the
> only way to waterproof a connection - only the messiest.
> Steve K7LXC
> TOWER TECH
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