Kim Elmore wrote:
>
>In an N-connector, isn't the center pin free to float around a bit?
Only in the original unimproved MIL types.
>Which types are the more reliable in this regard? Is Amphenol the magic
>word?
>
The magic word is "CAPTIVE", as in "CAPTIVE center pin". This feature
removes most of the uncertainties of freehand cable prep and assembly,
and mostly prevents the center conductor from moving inward or outward
over time.
But don't expect miracles - captive center pins are not strong enough to
prevent a loose 9913-type center conductor from slipping downward in a
long vertical run. That is a design fault in the cable itself, and after
a few years of constant downward force, the center pins can move due to
"cold flow" in the Teflon washers. The pin may be pulled inward at the
top of the cable run, possibly breaking the connection, while the pin at
the bottom end may be pushed clear out of the plug - or more likely, it
may cause damage to the mating socket.
(In my case it split the connector fingers on an expensive coaxial
relay. What with that and the water problem, I will NEVER use cable with
a loose center conductor again.)
The other big improvement in modern connectors is the compression-sleeve
type of cable clamp which grips the whole cable tightly, and presses the
braid down onto a "top hat" ferrule. This gives a very strong,
waterproof contact to the shield without any need for soldering. The
same cable clamp is also available on improved PL259 connectors.
We're leaving today for an Internet-free holiday season, so please
forgive me for making a posting to which I won't be able to respond. For
the same reason I don't have time to pull out any URLs for these
improved connectors, but they are easy enough to find once you're aware
that they exist. They are more expensive than the original MIL types,
but if you're in the market for *quality* connectors they are far better
value for money IMO.
Happy Holidays to all TowerTalkers!
--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek
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