On Wed, 16 May 2007 14:16:43 -0500, (Richard
Harrison) wrote:

Richard Clark, KB7QHC wrote:
"Richard, if you choose to challenge this, cite an explicit reference
that says Phase Velocity contains information and energy."

I already have in two previous postings in this thread. One quotation
was from Terman and the other was from Lenkurt. Both explained how a
traveling wave tube (TWT) works. It uses velocity modulation of an
electron beam to alter the phase and power of a signal carried by a coil
encircling the electron beam. There`s your information and energy.

Hi Richard,

If anything, these citations that you offer move at speeds
considerably SLOWER than the speed of light and is the whole purpose
of the design of their structure.

It was because of this slow speed that the triode structures of even
lighthouse tubes were abandoned as amplifiers. The electron beam
moves at sub-luminal speed and the helix was designed to not only
accommodate to the phase lag introduced by increasingly significant
time delays, but to synchronize to it by optimally delayed signals
wending along a retarding helix.

Now, do you have actual citations that support Phase Velocity carrying
information and energy at faster than light speeds?

73's
Richard Clark, KB7QHC

Richard Clark, KB7QHC wrote:
"Now do you have actual citations that support Phase Velocity carrying
information and energy at faster than light speeds?"

Yes, but I don`t necessarily believe them. Wikipedia gives recent
examples of apparent violations of the limit imposed by the speed of
light. However, I infer the editor did not believe them as proving a
violation.

On page 253 of "Transmission Lines, Antennas, and Wave Guides" by King,
Mimno, and Wing:

"This means that the phase velocity vpg is greater in the TM 0,1 mode
than in the TEM type and, therefore, greater than 3x10 to the 8th power
m/sac."

The 3rd edition of "Antennas" by Kraus, et al on page 255 is found Fig.
8-34 showing phase velocity versus helix circumference. Some helices are
shown with phase velocities exceeding the speed of light.

I was one who didn`t believe W8JI`s loading coil instantly induced
energy from one end to the other by magnetic induction.

Best regards, Richard Harrison, KB5WZI