"Ian White, G3SEK" wrote in message ...

Sorry, that is exactly wrong. S11, SWR and the impedance itself, do
*not* change when you connect a different instrument to the same load.
All the changes you have described are due entirely to instrument
errors.

That's how the instrument errors are determined... by knowing for a fact
that, whatever all the different instruments may say, the impedance
they're trying to measure is the one thing that has *not* changed.


You are right, but i never stated that the impedance we are
feeding ever changes, only the measured SWR.

Hey, we live in the real world, with real instrument errors. This
is the case i am talking about when i started the thread. I usually
DON'T measure the same SWR from antenna analyzer versus PA and meter
hooked up, and this may be due to the fact that the PA has a different
source impedance than the analyzer. I'm not claiming that the
impedance we are feeding has changed. And if you read my original
post, you will notice that the SWR didn't change when the coax length
was changed, mainly the incident power.

How would you explain what Cecil wrote? How are some people
improving SWR by changing coax length, when in theory they shouldn't
be able to do this?

Do you think the series reactance a system offers a PA may
actually improve it's incident power?

Slick