Pete Smith wrote:
> I have recently been exposed to several weatherproof enclosures using
> cable glands.
I've been using them for a long time, but my use is only for rotator and
control cables. Coax OTOH almost always goes through bulkhead connectors
to ground the shield at the enclosure. In theory that serves to keep
lightening out of the enclosures and also provide another ground. I
ground coax at the top and bottom of the tower as well as where it comes
into the house (or shop) through grounded bulkheads. Also, cables that
to to side mounted antennas, or antenna switches feeding the sloping
dipoles are grounded where they reach the tower and at the bottom of the
tower. The coax to the remote antenna switches then goes to a six-pack
in a large NEMA enclosure for SO2R operation and from there through
underground conduit to the bulkheads at the house and shop entrances.
> On the face of it, these devices seem to be a significant
> improvement over traditional ham radio weatherproofing techniques, which
> often rely on electrical tape or RTV for sealing. I'm wondering,
> though, if a single gland can be used with more than one wire.
It can but is unlikely to seal well.
> I have
> one situation where I want to bring a single wire and a small coaxial
> cable through one, and am a little skeptical about the integrity of the
> seal when this is done.
>
>
If you really need to do it, thoroughly coat the wires where they go
through the glad with coax seal. This will probably make it a bear to
fit through the gland but it will seal. The gland packing really needs
to fit tight to hold the cables going through so that might defeat the
mechanical stability of the fitting although it likely would still seal
unless the cables slipped out.
Myself, I stick with one gland, one cable. They are cheap and work well
when used as designed.
73
Roger (K8RI)
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