Cecil Moore wrote:
Keith Dysart wrote:
So the next question is: What is the phase change
at the terminals of the black box?

It just occurred to me that you and I may be talking
about two different phases.

---Z01---+---Z02---

Vfor1--|--Vfor2

Vref1--|--Vref2

I am talking about the phase shift in the forward waves
across the impedance discontinuity, i.e. the phase shift
between Vfor1 and Vfor2. The list of phase shifts is
the phase shift in the forward voltages at the impedance
discontinuity. It is different for all the black boxes.

If you are talking about the phase between Vfor1 and Vref1,
then, yes, that phase is the same for all the black boxes.
It is impossible for it to be otherwise.

I think that Vfor1 and Vref1 could also be understood to mean Vfor1 and
Vrefsum, with Vrefsum being the sum of all the reflected waves occurring
within the black box.

It strikes me that the concept of steady state AC is no different from
the concept of DC discussed earlier in this thread. Steady state AC has
no wave front to analyze. The impedance at the black box junction is a
fact, not something that can be analyzed with steady state waves. I
think you have said this a number of times.

The standing wave has no velocity, because we can not define a unit of
the wave that moves. I think you have also pointed this out.

Wave fronts must be used if we want to look into the black box, or at
least a MOVING sine wave so that we can look at the first reflection
separately. I think this is what you have said many times, but I used
different words.

73, Roger, W7WKB