Dr. Anton T. Squeegee wrote:

I would be prepared to debate this. A properly-done crimp
connection, made with high-quality connectors (I'm talking Amphenol RF
or King) and done with a high-grade crimper will be gas-tight. If you
enclose the whole thing in the sealant-lined heat-shrink tubing after
you've made up and tested the cable, there's no reason it won't do just
as well as a gland type.

I keep reading that crimp connections are more reliable than clamp type,
but my experience sure runs contrary to that conclusion. I have a
sizable quantity of patch and longer RG-58 cables with crimped BNC
connectors. Most are from the Tektronix surplus outlet, but some from
other industrial sources. All were presumably made by skilled people
with the proper equipment, and they were manufactured over a long period
of time. Yet on many cables, the outer insulation has pulled out from
under the crimp, leaving bare shield. Besides an obvious entry point for
water if used outside, the shield wires begin breaking from flexing
against the hard crimp connector end. In contrast, I've never had a
failure of cables I've made myself with crimp type connectors, although
some have gotten very severe and prolonged use.

I imagine that adding sealant-type heat shrink tubing would delay the
onset of the insulation migration problem and reduce shield breakage
after it occurs. But that's an extra step not required for clamp-type
connectors.

In addition, some "precision" cables made with double-shielded cable
were very RF-leaky at the connectors, a problem I solved by replacing
the crimp connectors with clamp type.

So I have what I've read on the one hand, and what I've experienced on
the other. The only conclusion I can reach is that it must be a lot more
difficult to "properly" assemble a crimp connector than most people
realize. I figure that if the pros have so much trouble doing it right,
I don't have a chance. I'll stick with clamp type. My feeling is that
the reason that crimp connectors have become so popular doesn't have
anything to do with reliability but simply that they're faster to
assemble and therefore cheaper.

And, with crimping, you stand a much lower chance of heat damage to
the insulation. ;-)

The only heat involved with clamp type connectors is in soldering the
center pin. Hopefully most people can manage that -- I've never had a
problem, anyway.

Roy Lewallen, W7EL