RadioBanter - View Single Post - Constructive interference in radiowave propagation

Owen Duffy · April 13th 07, 09:35 PM posted to rec.radio.amateur.antenna

(Richard Harrison) wrote in news:8451-461F926B-
:

Owen Duffy wrote:
"Richard "over a prolonged period" is a qualification, and still
doesn`t
sufficiently qualify the statement to be true."

Maybe not the best words, but they are true in the practical case. In
an
EM-wave, energy is being passed back and forth netween the electric and
magnetic fields on a periodic basis. At any given instant most of the
wave`s energy may reside mostly in one field or the other at a given
point. Half a cycle nas no practical significance among a million or
more.

Your paragraph above now talks about an EM-wave, my quote was about a
transmission line, let me repeat it to save you going back through the
posts:

"In the same vein, I saw an assertion without sufficient qualification
that in a transmission line, 50% of the energy is stored/contained in
the electric field and 50% in the magnetic field. Again, general
statements from specified cases."

They are not quite the same.

I am not quite sure about the concept of energy at a point that you
discuss, isn't it zero?

Owen