Which brands/types are the "good" ones? Maybe some of mine need
BTW, I don't think I've ever met a "substandard double F female" or a
substandard double D, for that matter. ;-)
Charles - K5ZK
I'm not sure which brands are bad, but I've been pretty lucky and not run
into any. It doesn't surprise me, with Chinese manufacturing quality, that
poor connectors are starting to appear. I think there is a risk people might
go overboard on connectors based on a few substandard connectors.
I started dealing with F connectors back in the 1970's. I was systems
engineer at a company that had many dozens or perhaps a hundred or so MATV
and CATV systems. With hundreds of thousands of connectors, we could not
tolerate even a small fraction of a percent connector failures.
All of the connectors we used, and I'm sure this applied throughout the
industry, were tin contacts. The last thing we would use was gold, because
gold would aggravate something we called "fretting corrosion" in contact
with copper clad steel, tinned, or CCA cables. Tin plating was excellent
under dry circuit conditions, like CATV drop feeds, where no significant
current flowed through the contact.
Tin plated contacts had to be protected from oxidation by a grease. The
grease also allows the connectors to be reused over and over without ruining
the tin. We found a 100% pure silicon dielectric grease best. We used a
product by GE back then, and I use something called automotive "tune up"
grease now. It looks and smells identical. Outside of lightning I have no
problems with hundreds of F connections in my system.
ALL connectors I have taken apart over the past 40 years have had spring
contacts. This includes trunk cable connectors. The spring is a two piece
deal that is sort of double V shaped from the side with one long leg. The
wire pushes the V point's apart. A good connection requires a pretty good
spring force. If you insert a piece of dry center conductor in the contact,
you should be able to feel the female grabbing the wire. It can't feel like
a zero insertion force connection, or you will have problems.
I would never use gold unless it was against gold. Tin is good for tin to
tin, tin to silver, and tin to copper. I know of CATV systems that installed
gold plated connectors and had to go out and remove them. I think Comcast
got into that once. Besides that, some gold connectors are not even real
gold. They are just gold colored "crap".
My suggestion is to ask advice from and use what the CATV industry uses and
has used for years. I know everyone thinks gold is magic, but it can be a
real headache even in cases where it really is gold.
The single most important thing in any connection is to NOT let a stray
stand get loose and short the connector, to prep the ends properly including
folding or not folding the shield as required by the cable and connector,
and to lube the connector with something to keep air and moisture out.
I have many hundreds of F's in my system, and I'm not particularly choosey
about picking certain brands of females so long as they pass the insertion
force and pull test (they have to have a definite grabbing friction when
dry) and are tinned center contacts. The last thing you will find around
here are gold connectors, unless they mate to another gold contact. I also
ALWAYS lube the connector with silicon dielectric compound.
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