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I found some isolated panel-mount BNC connectors which have an integrated capacitor for RF chassis-bonding, e.g. this molex part 73100-0090.

The datasheet contains this simple schematic to illustrate the connection of the terminals:

enter image description here

Obviously, the capacitor connects between the shell and the grounded parts (posts and compression clip).

But how is the pin electrode (A) connected in this scheme?

Image and 3-d view available here:

Kind regards.

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  • \$\begingroup\$ I assume that "A" is the center conductor. If so, I would end the "A" line with a small circle at the center of the larger circle, rather than continuing it across to the reverse arrow. The symbol as drawn seems confusing to me. \$\endgroup\$
    – Peter Bennett
    Apr 16, 2021 at 15:44

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From datasheet. A is shielded conductor.

enter image description here

Symbol is IEC60617. From IEC60617 .

enter image description here

Coaxial plug and socket If the coaxial plug or socket is connected to a coaxial pair, the tangential stroke shall be extended on the appropriate side.

enter image description here

Female contact (of a socket or plug) Socket.

So Molex's schematic symbol is a blending of the alternative input connection (03–A2–01) with coaxial socket (03–03–15).

A is the central contact, B is the BNC connection, C is the connector chassis and compression spring. C is isolated from B by an integrated capacitor [9.4nF] for RF chassis-bonding (OP).

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  • \$\begingroup\$ Correlate everything and this will be a great answer: A is the pin, B is the BNC ring/cylinder, C is the BNC threads and compression spring. It is not clear from the drawings, but B must be isolated from C. There is a cap from B to C. \$\endgroup\$
    – Mattman944
    Apr 16, 2021 at 15:46
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A (the coaxial connector Center contact) is directly connected to the "A" PCB solder pin.

"C" in the diagram above, appears to go to from the outer shell of the coaxial connector to the chassis, via a compression 'spring' flange, as shown in the datasheet (see center of the datasheet). I think "C" in this case does not stand for 'capacitor'.

"B" is also the shell (outside) of the coaxial connector, and goes directly to the "B" PCB solder pin.

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  • \$\begingroup\$ The datasheet clearly mentioned the integrated filtering cap of 9400 pF, X7R, so there is a capacitor. Also: How is A connected to B ? What does the arrow tip mean between A and B ? \$\endgroup\$
    – tobalt
    Apr 16, 2021 at 14:33
  • \$\begingroup\$ The datasheet seems to be unnecessarily confusing, lacking call-outs, and showing what appear to be erased features for the "B" pcb pin. An actual photo of the part would be informative. \$\endgroup\$
    – Chris Knudsen
    Apr 16, 2021 at 14:33
  • \$\begingroup\$ Yes, one end of the cap is attached to the outer coaxial conductor, the other end to the compression spring (that should contact the chassis when the jack is mounted in a metal box). \$\endgroup\$
    – Chris Knudsen
    Apr 16, 2021 at 14:35
  • \$\begingroup\$ added image link and 3d view to the OP \$\endgroup\$
    – tobalt
    Apr 16, 2021 at 14:35
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    \$\begingroup\$ A, B, C are terminations (with A, B being PCB pins and C being a chassis contact). The "A" solder pin goes to the "<" jack pin, that accepts a male contact from the coax connector. It's unfortunate that the center of the "<" hits the shield 'circle', implying a connection from"A" to "B" (where there is none). If there were a connection, it would be a dead-short. It's a confusing symbol, with an unclear datasheet. \$\endgroup\$
    – Chris Knudsen
    Apr 16, 2021 at 14:46

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