On Sun, 08 Apr 2007 03:32:48 GMT, Owen Duffy wrote:

Walter Maxwell wrote in
:

is correct. Please review the QEX article I referenced above to see
it. With all due respect, Owen, I believe you have misunderstood, or
perhaps misconstrued the procedure I presented. Would you please
review it again to see where you might have gone wrong?

Hi Walt,

I have reviewed Chapter 3 of Reflections II which you kindly sent me. I
think it contains the deveopment to which you refer.

It seems to me that Chapter 3 depends entirely on an assumption that the
phase relationship of the current and voltage of a travelling wave is 0 deg
or 180 deg, depending on the direction. This only holds true for lossless
lines and distortionless lines, and so the "proofs" developed in the
chapter are not general proofs. For example, the proof that reflected power
is purely real and of magnitude |E-|^2/Zc is not developed for the general
case, and happens to not be correct for the general case.

Owen

Owen, your statement that my writings in Reflections are flawed is shocking. The feeling I get from it is like
getting sucker punched in the stomach.

Are you so narrowly oriented academically that the difference between lossless and low-loss conditions is so
great that general principles cannot be applied to situations where real-world low-loss elements are involved?

It is generally accepted that voltage and current travel forward on a low-loss line with 0° phase difference.
In low-loss lines the effect of the small negative-reactance component in the Z0 due to the loss is routinely
disregarded as insignificant. Likewise, when voltage and current travel rearward on a low-loss line, resulting
from reflection at a mismatched termination, it is generally accepted that they travel with a 180° phase
difference, disregarding the small error caused by the insignificantly-small reactance in the Z0.

Calculations performed when disregarding the small error still yield practical results in hands-on operations.
On the other hand, if everyday practical operations required calculating with the academically-perfect
conditions of the Z0, time would be lost due to the unnecessary complications involved in the calculations.

Your stated position is that applying general principles that are academically correct only with lossless
elements to operations involving low-loss elements is flawed.

C'mon, Owen, let's get practical and rescind your impeachment of Reflections.

Walt