Martin,

You're absolutely correct - the push on BNC connectors are junk,
pure and simple. Their only claim to fame is that they will get you
working, right now - but they won't stay working for long! The
crimp-on BNC connectors are just slightly better, even if you invest
big bucks in the special crimping tool. They work for a bit, but they
just won't stand up to normal usage.

The best BNC connector is definitely the one with the soldered center
conductor, with the braid held solidly inside the body by a ferrule
locked by a nut, and a vinyl strain relief over the body of the
connector. They're not easy to make, though, even with lots of
practice. They usually fail because either the center conductor strands
or the shield braid get nicked slightly during assembly. Another
failure is due to corrosion of the braid or the center conductor.
Neither of these failure modes can easily be found in the field, until
things suddenly stop working.

You can see why I was concerned with the possibility of an ELT failing
suddenly when it was most needed.

-John