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Old June 14th 10, 12:50 PM posted to rec.radio.amateur.antenna
Gaius Gaius is offline
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First recorded activity by RadioBanter: Oct 2009
Posts: 18
Default BNC connectors 75 Ohm versus 50 Ohm?

In article ,
says...

On 06/13/2010 01:50 PM, Sal M. O'Nella wrote:

[Sorry for being a little late to the party, but I was off newsgroups
most of this week.]

This thread had some discussion of adapters and I want to share my bad
experience with some low-cost items, proving, once again, that you get
what you pay for.

I am testing all my adapters and discarding some because the assemblies
are pulling apart with very little force. One manifestation: tightening
the threaded ring on a PL-259 (either cable end connector or adapter)
and having the ring just continue all the way on, separating from the
connector body.

One test for a future failure has been any lack of smoothness when I
rotate the ring while tugging it gently. If it binds, rather than
turning smoothly in my hands, it's going to fail. Also, some of the
cheap connectors are press-fit together very poorly; they pull apart
with only a few pounds of pull.

Most of my early exposure to coax connectors was in and around the US
Navy, where reliable connectors are the rule, so I was a spoiled child.

"Sal"
(KD6VKW)


PL-259's I can handle.
BNC's drive me nuts trying to get a good connection.
I gave up and just buy my cables now.
Bill


Sal's right - it's down to the quality of the item. I've seen some poor
BNCs, but many PL-259s which were REAL rubbish. I expect it's because
many of them are used for CB - and price is the usual decider there.

I've standardised on 50R BNCs for everything. Usually Amphenol or
Greenpar - the extra cost is insignificant, compared to rig prices these
days. Why 50R - the only reason is that the sockets are more robust.

Ready made BNC cables have been a disappointment - they are usually
crimped, and the crimps seem to relax with age. Cables can pull out,
given a bit of a tug. I use solder/clamped connectors and always solder
the braid to the clamping sleeve. Never had a failure.....