Walter Maxwell wrote:
On Sat, 14 Apr 2007 16:04:55 -0700, Roy Lewallen wrote:

Walt, before digging into your recent posting, I'd really like to get
one issue settled. I think it would be helpful in our discussion. The
issue is:

Can you find even one example of any transmission line problem which
cannot be solved, or a complete analysis done, without making the
assumption that waves reflect from a "virtual short" or "virtual open"?
That is, any example where such an assumption is necessary in order to
find the currents, voltages, and impedances, and the magnitude and phase
of forward and reverse voltage and current waves?

Roy Lewallen, W7EL

No Roy, of course not. I am not attempting to assert that reflection coefficients should be used in such an
analysis. I'm only asserting that it's another way of performing an analysis, one that I believe paints a more
visible picture of the how the pertinent waves behave in the circuit.

We're certainly not communicating well! I have never questioned that the
use of "virtual shorts" is another way of performing an analysis, nor
that it helps visualize some of the things going on.

If I still haven't persuaded you that it's a viable way of analyzing the impedance matching function then I'll
back off and not pursue the issue any further.

Nor have I questioned that it's a viable way of analyzing the impedance
matching function.

If you'll read what I've written, you'll hopefully see that my only
point of contention is with your claim that waves reflect from a
"virtual short". They do not. And the lack of a single example of a
system whose analysis requires this to happen is evidence that they do not.

If you back off and not pursue the issue any further, you'll continue
with your belief that "virtual shorts" cause reflections. And I'm afraid
that will detract from the wealth of accurate and useful things you do
say. So please continue. But don't waste time arguing that the concept
of "virtual shorts" is a useful analytical tool. I've always agreed with
that, and haven't seen any postings indicating anyone else doesn't.

Incidentally, you didn't answer my questions.

I wanted to get an answer to mine, first. Now that I have, I'll answer
yours.

Roy Lewallen, W7EL