Gene Fuller wrote:
Cecil Moore wrote:
Jim Kelley wrote:
You seem to be implying that there's something different about how
these electromagnetic waves change direction compared to other
electromagnetic waves. Why is that?

There is something different but not unusual. We don't
often observe wave cancellation of visible light waves
because of the problem of getting coherent beams of light
perfectly aligned. Yet, we experience RF wave cancellation
every time we adjust our antenna tuners for a Z0-match
because the perfect alignment of coherent RF waves inside
a piece of coax is an automatic given.

This is a rather curious notion. Where did you get the idea that waves
must be perfectly aligned to "cancel"?

Apologies - what I meant to say was that waves must be perfectly
aligned to totally cancel. When I say "wave cancellation", I
am usually talking about total wave cancellation, as occurs at
a perfect Z0-match. I will try not to make that same mistake
in the future.

Waves need not be perfectly aligned to partially cancel.
Waves must be perfectly aligned to totally cancel. Hope
that clears up the confusion about what I meant to say.

And of course, partial wave cancellation can extend from
almost none to almost total. However, total wave cancellation
obviously requires perfect alignment.
--
73, Cecil http://www.w5dxp.com