[Towertalk] SWR & Speed of Light?

[Jon Ogden]

on 9/26/02 1:01 AM, Michael Tope at W4EF@dellroy.com wrote:

> Group velocity or perhaps more aptly "information velocity" is always less
> than or equal to the speed of light in a vacuum, but the "phase velocity" or
> the speed at which a constant phase point on an electromagnetic wavefront
> progates along the wall of a waveguide can actually exceed the speed of
> light in a vacuum. This is analogous to a wave hitting the beach at a
> slightly
> oblique angle (as opposed to head on).

Thank you for the correction!  You are right.  Been a long time since I
studied EM wave theory!  That was a good refresher course!

73,

Jon
NA9D

-------------------------------------
Jon Ogden
NA9D (ex: KE9NA)

Life Member: ARRL, NRA
Member:  AMSAT, DXCC

http://www.qsl.net/ke9na

"A life lived in fear is a life half lived."