"Reg Edwards" wrote
Provided the mechanical connection is sound, you can use any coaxial
connectors you like, regardless of nominal impedance, at frequencies less
than about 300 MHz without any observed ill effects.
_________________

??? Using connectors that don't maintain the characteristic impedance of the
transmission lines they connect _will_ produce undesired effects. The
effects may be negligible to amateur radio operators used to operating
transmitters into rather high mismatches, but they would never be tolerated
in most professional operations, including high-power broadcast systems.

Years ago a common impedance for rigid transmission line used in broadcast
systems was 51.5 ohms. Later the more common value was/is 50 ohms. While a
mechanical adapter was available to allow connecting a 51.5 ohm inner
conductor to 50 ohm inner conductor (SWR= 1.03), better installations
installed an RF transformer section at these interfaces.

A 1.1 SWR at the input of a TV transmit antenna using ~500 or more feet of
transmission line will produce a visible "ghost" in the transmitted picture,
as seen by a careful observer. At 1.25 SWR it can be seen, and will
objectionable to almost everyone.

RF

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