| George, W5YR wrote:
| ...
| The condition
| that the real part never be negative
| is shown to be
| that Xo/R0 is equal to
| or less than unity.
| ...

Unfortunately,
I am afraid this is
_not_
the case at all.

Exactly, the related lines have as follows:

"The condition that Pr should never become negative is that
|p(z)|^2 + 2(Xo/Ro) Im p(z) = 1
Expanding p(z) from (7.33) with Zo = Ro + jXo and Z(z) = R(z) + jX(z),
it is easily found that this reduces to the condition |Xo/Ro| =1,
which has already been seen to be true."

Mrs. yin,SV7DMC, who has repeated, checked and solved
all of this book materials, except perhaps a few,
forewarns of that:
Every time Chipman says "easily", probably implies
"as I heard or read or something like that".
How else can someone explains,
why the proof of every such claim by him,
it happens to be a so cumbersome one?

This is true especially this time.

If someone follows the Chipman's hint,
the equivalent condition at which "easily" arrives
is only Z(z) = 0.
[e.g. in the thread
'Complex Z0 - Power : A Proof' - The Missing Step]


After that,
this last condition is unquestionably valid at the terminal load,
when we impose Z(l) = Zt = Rt +jXt, with Rt = 0.

At every other point it is still an unproven, open, problem,
at least to me.

But there is a chance to finish with this matter...

According to Mr. Tarmo Tammaru/WB2TT
in the thread 'Complex line Z0: A numerical example':

"I did a search, and came up with a Robert A Chipman, age 91, in Toledo OH.
From my recollection, the age is about right, and Toledo is where I saw him"


Therefore,
I think it is the most appropriate time,
someone curious enough of you,
who leaves somewhere near by him,
to go and ask him about it.

Is there any volunteer?

Sincerely,

pez
SV7BAX