Richard Clark wrote in
:

On Fri, 02 Mar 2007 00:18:02 GMT, Owen Duffy wrote:

The case that is plotted is an extreme mismatch, ou you might argue
impractical, but it is extreme enought to show the effects clearly on a
graph. The x axis is displacement from the load (-ve towards the
generator).

Hi Owen,

Chipman shows much the same work in Chapter 8. If you got a copy you
might find it an useful resource as his math and discussion goes well
beyond the usual coverage.

Re Chipman, no I don't have Chipman on the shelf. It sounds like I am
poorer for that, but there you go. Allmost all of what I have stated here
is based on just two things:
- that V/I=Zo for a travelling wave in a transmission line, and that
(Vf+Vr)/(If-Ir) at the load end of the line must equal Zload;
- that the voltage or current decays as e^(gamma*x).
Both are explained in probably any transmission line text, but the graphs
I created show a picture that, IMHO, is worth the proverbial thousand
words. Exploring the shape of the lines is revealing.

For example, you will remember Dr Ace (IIRC) asserting that rho cannot be
greater than 1, and supporting that with the challenge to demonstrate
rho1 with a Bird 43. Of course the Bird 43 cannot demonstrate rho1, it
is calibrated for Zo=50+j0 and rho1 is only possible if Zo has
sufficient -ve reactance to create an observable rho1 on a suitably
inductive load. So, at the risk of exciting another debate, rho can be
greater than one, but the maths that supports that proposition also
explains why you wont observe it on a Bird 43.

Owen