>The impedance determining portions of the BNC connector are
>exactly the same as those of the N type connector.
Agreed. The proportions to the equation that determine characteristic
impedance are the same for any 50-ohm connector. My specific wording was
that I don't consider the BNC to be a "true" constant impedance connector
because of the swept impedance bumps I've seen on instrumentation test
cables at frequencies above 500 MHz. The "N," "TNC," and "SMA/SMB" types
exhibit superior "constant" characteristics when swept at the higher
frequencies, particulary properly crimped "N" and sexless GR types.
>This is probably correct. I also doubt that it is either a 50 or
>a 75 ohm connector. But the point is simply that it is NOT a
>controlled impedance connector (for any particular impedance) and
>as such is equally applicable to either impedance line. Note
>that they don't make different versions of this connector for
>different impedances as they do for the controlled impedance
>types.
Agreed again. However, I am sure that the PL-259 can be calculated to
*some* characteristic impedance using the formula to derive the
characteristic impedance of coaxial cable. Although, the PL-259 has been
connotated as a "UHF" connector, sweeping it to the upper UHF frequencies
reveals that (arguably) it should not be used in critical applications above
100 MHz or so.
-Paul, W9AC
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