Bruce wrote:
Something like an annular ring capacitor that insulates the BNC body from the chassis whilst capacitively shorting it to the Chassis at RF ??. Followed by a freeite sleeve/bead arround the connector body or the coax connecting the signal from the connector to the PCB?
Back in the imagineering era of the various signal-egress abatement programs there were some connectors made like that (though not BNCs) -- in effect, the body of the connector was the center conductor of a feedthrough capacitor, and it in turn was drilled through for the insulator and center conductor as with any coax connector. You used a big ferrite bead around the coax just ahead of the connector to provide some resistive inductance. It was later shown that two SMT caps with very short loops worked just as well at all but the higheset frequencies (several tens of GHz and up). I have since run into a few of the connectors at hamfests and university flea markets, but I haven't seen any new ones for decades.
Most equipment these days just uses non-isolated connectors, all placed in close proximity on the chassis and bonded tightly to it. If you're careful with what goes on inside the box you won't *cause* any circulating ground current. Of course, this won't fix a ground loop caused by another piece of equipment, but the prevailing theory is (and has been, for some decades) to identify and fix the malfeasor on a case-by-case basis rather than expect every piece of equipment to fix ground loops between other items that are connected to it.
Best regards, Charles _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
