Richard Harrison wrote:
Roy Lewallen, W7EL wrote:
"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."

Seems to me they do.

I wonder if we can agree that if there is no physical
impedance discontinuity, there can be no reflections?

For instance, given a piece of 50 ohm open-ended coax
with a driving source:

source-----50 ohm coax-----+---1/4WL 50 ohm coax--open

There is a virtual short at point '+' and that virtual
short exists at a point where there is no physical
impedance discontinuity. Can we agree that the forward
wave is unaffected by that virtual short? Can we agree
that the reflected wave is unaffected by that virtual
short? After all, there is absolutely nothing there
that can physically disrupt any waves.

Or given one wavelength of coax being driven by a signal
generator equipped with a circulator load.

SGCL---1/4 WL---x---1/4WL---y---1/4WL---x---1/4WL---open

There are obviously reflections at the open. Are there
any reflections at the virtual open at 'y'? Are there
any reflections at the virtual shorts at 'x'? I would
submit that in the above example, the *only* reflections
in the entire system are happening at the open end of
of the coax and that the virtual shorts and opens are
themselves effects and not the cause of anything (except
maybe arguments) :-)
--
73, Cecil http://www.w5dxp.com