christofire wrote:



So refreshing to see someone stating it correctly when all around there are
folk who harbour mistaken beliefs that 50 and 75 ohm BNC pins have different
mating diameters. What I find odd is that so many people who claim the
contrary appear to have unshakable belief, almost like a religion,
irrespective of what the manufacturers' engineering drawings actually show.

Chris


Ns have different pins, not BNC.

Like I said, we "permanently" adapt N to BNC inside the lab. I've never
used an N in a situation where a BNC wouldn't have worked*. I guess the
threads make the connection more permanent, but now we have the TNC for
that.

*Check that. I did need a 75 Ohm N jumper once to get from a 7/8" line
to the back of a Moseley STL receiver.

Aside from power and sweep checks on 800 and above (where issues really
show) BNC seems to do well. Most RG58 double shielded types seem to be
lossy though. Even for short jumper runs. PL259 junctions are completely
worthless and measurements are meaningless. Sweeps are impossible because
of all the reflections. N can be adapted to anything else with much less
loss than from anything else. I was aware of this long before I built my
brand new Heath HW-2036 synthesized rig and replaced the RCA phono jack with
a BNC bulkhead as I built it.

Some of our more expensive equipment would get a N male to N fem adapter
just to save wear on the threads, but N male to BNC fem adapter would be
most useful most of the time. It's bad luck to use the internal load when
you can use a sample port anyway.

My stock Collins HF amp has an N output connector and it's 40+ years old.
BTW it has an RCA phono jack for the input. These actually have better loss
characteristics to uWave than the SO239 except for lack of proper retention.

"Dave" wrote in message
m...
christofire wrote:



So refreshing to see someone stating it correctly when all around there
are folk who harbour mistaken beliefs that 50 and 75 ohm BNC pins have
different mating diameters. What I find odd is that so many people who
claim the contrary appear to have unshakable belief, almost like a
religion, irrespective of what the manufacturers' engineering drawings
actually show.

Chris
Ns have different pins, not BNC.


Correct.

http://www.amphenol.com/markets/medi..._coax/bnc.html '50 ohm
and
75 ohm BNC connectors are intermateable'

http://www.radiall.com/radiall/easys...goryId/1232281
'All versions are fully intermateable'

An earlier post in this thread had suggested otherwise.

Chris

JB wrote:
Like I said, we "permanently" adapt N to BNC inside the lab. I've never
used an N in a situation where a BNC wouldn't have worked*. I guess the
threads make the connection more permanent, but now we have the TNC for
that.

*Check that. I did need a 75 Ohm N jumper once to get from a 7/8" line
to the back of a Moseley STL receiver.

Aside from power and sweep checks on 800 and above (where issues really
show) BNC seems to do well. Most RG58 double shielded types seem to be
lossy though. Even for short jumper runs. PL259 junctions are completely
worthless and measurements are meaningless. Sweeps are impossible because
of all the reflections. N can be adapted to anything else with much less
loss than from anything else. I was aware of this long before I built my
brand new Heath HW-2036 synthesized rig and replaced the RCA phono jack with
a BNC bulkhead as I built it.

Some of our more expensive equipment would get a N male to N fem adapter
just to save wear on the threads, but N male to BNC fem adapter would be
most useful most of the time. It's bad luck to use the internal load when
you can use a sample port anyway.

My stock Collins HF amp has an N output connector and it's 40+ years old.
BTW it has an RCA phono jack for the input. These actually have better loss
characteristics to uWave than the SO239 except for lack of proper retention.


I have a 30L-1. Some day I'll hook it up.