Ian Jackson wrote:

In message , rickman
writes
On 7/7/2015 6:25 AM, Ian Jackson wrote:
In message , Jerry Stuckle
writes


Sure, there is ALWAYS VSWR. It may be 1:1, but it's always there.

If there's no reflection, there can be no standing wave. So, being
pedantic, there's no such thing as an SWR of 1:1!

Why do you say that? If there is no reflection the voltage on the line
is purely due to the forward signal and so the VSWR is 1:1. What's
wrong with that?

A standing wave is caused by a reflection. If there IS no reflection,
there is NO standing wave. So while you can have an SWR of
1.00000000000001-to-1 (because a standing wave DOES exist), you can't
really have one of 1-to-1 (because there IS no standing wave). ;o))
[Just a bit of pedantic, lateral thinking on my part. Don't worry too
much about it. It has absolutely no bearing whatsoever on the current
discussions.]

Quite so: a voltage standing wave *ratio* of 1 means no standing wave.
But in the name of the unit the "standing wave" is adjectival, and it is
still a valid name even when there is no standing wave. And, anyway,
you can still colloquially have a resistance of zero ohms even for a
superconductor!
--
Roger Hayter