[HCARC] Coax Connector Sealing Stuff

Kerry Sandstrom kerryk5ks at hughes.net
Mon Oct 22 15:05:22 EDT 2012


Gary,

If you are really concerned about weather proofing and keeping moisture out, 
the best approach is to use weatherproof connectors which is, for most hams, 
a type N.  When you seal a connection, you have to seal it all, both the 
plug (PL-259) and the socket (PL-258) if you are joining two cables with a 
'barrel'.  An SO-239 socket is very difficult to deal with.  The back side 
isn't enclosed.  On many that I've seen, the mechanical joint between the 
insulator and the outer and inner conductor/shell isn't very tight.  I'm 
sure moisture can get through that and into the coax.

I believe that solid dielectric coax is less sensitive to moisture than foam 
cable so unless you really need the lower loss, I'd avoid the foam cable.

The worst part of sealing coaxial connectors is the problem with coating 
anything:  If anything happens, your only choice is to cut the connectors 
off and start fresh.

Cushcraft used to provide a little plastic boot with their antennas to 
protect the PL-259 from the weather.  The PL-259 was connecrted to an SO-239 
style connector that seemed quite flimsy and had nothing to protect its 
back.  It looked nice but I don't think it did anything!

No, I don't use anything on my connectors.  I use UHF series connectors on 
my 80/40/30 vertical and type N at higher frequencies.  I also use solid 
dielectric cable.  I use a size bigger than normal, RG-217/U with solid 
dielectric for mechanical strength and less moisture issues and take the 
slightly greater loss.

Kerry 




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