Dr. Slick wrote:

I disagree on this point. You are caught up in the 50 Ohm world,
which i admit is easy to do. The SWR is based on the ratio of the
forward to the reflected power.

That's not correct. The SWR (more correctly VSWR) is, by definition, the
ratio of the highest to lowest voltages which appear on a line long
enough to have both a maximum and minimum. It can be calculated from the
forward and reverse voltage waves. ISWR, the current standing wave
ratio, is numerically equal to the VSWR.

If you had an analyzer that was
calibrated to 20 Ohms (the same as normalizing the Smith for 20 Ohms
in the center) you would certainly have reflected power and high SWR
going into a 50 Ohm load.

And a 20 Ohm load would have a 1:1 SWR.

Loads do not have an SWR, only transmission lines do. The fact that you
get a reading on an SWR meter when it's connected to a resistor doesn't
alter that.

You have to realize that an SWR meter isn't really measuring SWR, as Reg
has repeatedly pointed out. It's actually measuring an impedance, and
reporting that on a scale marked SWR. So you have to be careful to avoid
making the mistake of confusing an SWR meter reading with the SWR on a
cable it's connected to. The two correspond only if the cable's Z0
equals the SWR meter's.

Likewise, you have to realize that you don't change the SWR or
"reflected power" when you change the normalization of your network
analyzer or Smith chart. Those things are a function only of the load
and transmission line impedance, not on your measurements or calculations.

Roy Lewallen, W7EL