Cecil Moore wrote:
Roger wrote:
There is a third possibility. The interaction of the two waves can
establish a very high resistance, so high that no current flows-zero.

This is a common confusion of cause and effect. Take a
short-circuit 1/4WL stub for instance. A very high
resistance is established at the mouth of the stub but
that high resistance has zero effect on the forward current
which keeps on flowing into the stub. Without the forward
current flowing uninhibited into the stub, the very high
resistance could not be maintained. In fact, the current
is a maximum at the shorted end of a 1/4WL stub. If you
don't believe it, measure it. Where did that current come
from if current cannot flow into the stub?

Stored in the 1/4 WL between the short and mouth. No more current
needed once stability is reached.


The stub impedance is the result of the ratio of voltage to
current. It is a virtual impedance and since it is an effect,
it cannot be the cause of anything. The people who say that
a virtual impedance is the same thing as an impedor have not
read the definitions of those things in the IEEE Dictionary.

Measured in ohms, virtual, and impedance is not the same as impedor. OK
An effect caused by earlier events. Agreed.

73, Roger, W7WKB