Re: Francophones

In message <vkckph$1cvdj$1@dont-email.me>, Jeroen Belleman <jeroen@nospam.please> writes

On 12/23/24 18:58, Ralph Mowery wrote:

In article <nnd$23e91f0d$053bf96e@d25fd620e9918bf1>, noreply@ademu.nl
says...

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On 2024-12-23 16:22, Ian Jackson wrote:

For many purposes you can ignore the difference between the 50 and 75 ohm impedances (and 60 if you ever come across any).
However, be very aware only BNC 50 and 75 ohm connectors are mutually mechanically mateable (yes - they really are!). I don't know if any others that are.

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Not recommended.
The center pin differs, a 50 Ohm BNC pin is thicker and may damage a 75 ohm BNC.
I'm cautious, most of my below 1 GHz equipment is 75 Ohms (from CATV company), the rest is 50.
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 It is the N connector the center pin is different.  The BNC pin is the
same.  It is the ammount of dialectric (insulation) in the BNC that
makes it a 75 or 50 ohm connector.
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N connectors are good, but the fact that 75 and 50 Ohm connectors
are similar enough to mate, but not nearly enough to do so without
damage or malfunction is perverse. When I took charge of the
electronics lab, it took a while to sort them out and to eliminate
the victims of mismatched matings. (I was always amazed at the
sheer quantity of connectors in a busy lab.)
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For BNCs, there *is* a difference, but it doesn't usually matter.
I kept 50 and 75 Ohms separate, but when put to the test, many
75 Ohm connectors turned out to really be 50 Ohm ones in disguise.
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In a pinch, BNC and N can even mate between them. I'm not sure if
that's deliberate or accidental.
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Yes - the 'innards' are essentially the same. IIRC, the BNC innards also mate with C-connectors. I think it's deliberate. After all, its the innards that carry the RF.
--
Ian
Aims and ambitions are neither attainments nor achievements