On Wed, 29 Jun 2005 14:24:44 -0700, Frank Gilliland
wrote:

And #4 is exactly why #1 is incorrect: the 'characteristic' impedance
of a coax is constant, but it's 'input' impedance varies according to
load mismatch at the other end. If it wasn't for this fact, a tuner at
the radio end would be useless. But the point here is that if the SWR
meter is left floating with the coax shield (both of which should be
RF grounded) then the measurement can be darn near anything.
*****

What I will agree with is that the impedance seen at the input to the
coax is a reflection of the load impeadance as transformed, altered if
some don't like the word transformed, by the length of the coax. I
have no problem with that. Still this impedance is highly dependant on
the load and its reflection coefficient.

Correct the characteristic impedance of the coax never changes and
that was what I intended with #1.


james