In article _zDMf.22547$pE4.21635@trnddc04,
"Dale Parfitt" wrote:

.

BNC connectors are more commonly 50 ohms.

--
Telamon
Ventura, California

Just depends on what you specify when you buy the BNC connector. Just don't
try to mate a 75 Ohm BNC with a 50 Ohm BNC- same holds true for 75/50 type
N.
We recently built a high power 50--75 Ohm matching section for a CA
company. The unit had warnings that the output was 75 Ohm connector (their
choice). Got a call that they had destroyed the fingers on the 75 Ohm side
by screwing in a 50 Ohm mate. Very expensive mistake for them.

Yep, you sure can't go mixing different impedance connectors. One
parameter that determines the impedance of the connector is the spacing
of the center to outer conductor so even if they look the same they
will not mate properly and stuff gets broken.

There are very small differences in contact dimensions you need to
measure with a micrometer in the microwave region so connectors don't
get busted and you need to use a torque wrench or the performance will
not be to specifications. Reflection measurements are very picky about
using the right torque on connectors.

It always pays to look closely at the connector before screwing
something together in case a connector has already been ruined as
another lesson learned in the lab.

--
Telamon
Ventura, California