On 11/13/2013 7:29 AM, Paul Christensen wrote:
I've given up on the traditional solder-type PL-259s. Now I use the
crimp on
type and have never had a failure. The crimper is expensive but well
worth
the time and hassle saved. I got both crimper and connectors on eBay.
There
are many sizes so be sure you get the right ones.
I started using crimps for indoor installations. Outdoors, I still
prefer soldered PL-259s.
All inside cabling is RG-400. The crimps have held up well except for
one recent failure: The connector body had separated from the ground
sleeve end that's inserted onto the braid. What's strange is that since
the crimp is still strong and intact, the connector looks fine to the
eye -- but the body now rotates when the sleeve is held firm. These
are high-quality crimped connectors from Amphenol.
I've never had it happen with Amphenols, but I have had crimp UHF
connectors with a lot of side force break.
IIRC the the sleeve and body are held together with a simple flare
crimp, for lack of a better name.
(the sleeve has a slightly smaller OD at the end. this id a press fit
into the body and extends through the body so the end can be flared
slightly. It's a tiny amount, but normally grips well)
If enough side pressure, or torque is applied, I would think it could
fail in the manner described. That is if the connector is assembled in
the manner I think it is. UHF connectors are not meant to hold much
load, so mechanically I'd not expect the physical structure to be
designed to hold much either.
With LMR-600, this is a weak point and the larger cable can present much
more of a mechanical load to the connector. I've had them break off
completely at this point. That may be one of the reasons why the UHF
connectors for LMR-600 are so much more expensive. That and they are a
low volume product in comparison.
I need to dissect a connector to see just how they are constructed. If I
can do it neatly enough I'll put up a file. If I could figure how to
mount the cut off tool in the mill, I should be able to get a clean cut.
They do make thin cut off saws for the mill, but the arbor and blade
are kinda pricey to just cut some connectors apart as an experiment.
You can easily spend more on accessories in a machine shop than for ham
radio and quickly if you want to do much. <:-))
The crimp worked so well that the connector is actually usable until I
cut it down and install a new connector. Not sure how this happened.
The PL-259 is installed on the back of a transceiver and because it's
protected in a deep compartment, there's little chance that it
Could be the bending force if the LMR-400 was not bent before it was
connected? I can only guess at this point.
could.have bumped into something and broken that way.
It doesn't normally take much leverage to break one loose, or off
relatively speaking. OTOH it's not something I'd normally expect.
I would pitch such a connector though as that represents a possible high
resistance joint, even if it handles little current.
73
Roger (K8Ri)
Paul, W9AC
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