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Gaius · June 6th 10, 08:23 PM posted to rec.radio.amateur.antenna

In article ,
says...

A 75 ohm BNC plug is identical to a 50 ohm
one, save that the male pin in a 75 ohm plug is smaller in diameter.
The other way round, a 50 ohm BNC plug will damage a 75 ohm BNC socket.

Sorry. Not so. This is one of the most common urban myths in RF
engineering. The pin diameters of BNCs are identical between 50 and 75R.
(Measure them !!)

The 50R and 75R connectors are mechanically compatible in BOTH
directions. Don't take my word for it - check Amphenol's specifications:
"Two distinct types of 75ohm BNCs are available, and both mate with each
other and with 50ohm BNCs. "

I've been using 75R and 50R interchangeably for about thirty years, and
I've had NO mating damage problems. (Mismatches don't worry me - HF
only).

Note - type N and type C connectors WILL be damaged if you try to mix
75R and 50R varieties. I suspect this is the source of the BNC myth.

Also - some Chinese made BNCs are so badly made that they will damage
other connectors - but this is a manufacturing tolerance issue.