"Steve Nosko" wrote in message ...
OH! NO! Vortex vs. Bernoulli

Actually, it's Circulation vs. Newtonian vs. Bernoulli -- all three
are different mathmatical means of describing accurately and precisely
what happens when a airfoil produces lift. Actually each is simply a
different way of expressing exactly the same thing, but none of them
translates well to a real-life understanding of the concept. One of
the problems is that causes and effects get confused and
oversimplified by the math.

Much the same with reflections, transmission lines, and impedance
matching. While reflections do indeed exist on transmission lines when
mismatched to a source or load, they simply create standing waves.
Standing waves create non-optimum impedances depending on the
characteristics and length of the line. These impedances interact with
source and load impedances in very predictable and calculated ways.
Efficiency of power transfer is then determined by optimizing the
matching of these impedances. Optimimizing impedances then eliminates
reflections --- a circle of causes and effects.

Mathmatically, it's more expedient to skip much of the in-between
cause-and-effect stuff, and jump directly to describing the entire
process as a direct relationship between reflections and power
transfer -- which causes problems when attempting to visualize or
explain the process -- because that's not the way it really works.
It's not quite that simple and direct.

A standard SWR meter is a good example. It can't conveniently measure
reflections OR standing waves, so it measures mismatch. Since
everything is directly related, it could be said that it measures
reflections -- but it really doesn't. So, it doesn't really matter
unless you try to understand how the meter works in terms of how it
measures reflections or standing waves.

Al