"Yuri Blanarovich" wrote in message
...

From Kraus: Antennas

" 1-1. Definitions. A radio antenna may be defined as the structure
associated with the region of transition between a guided wave and a
freespace wave, or vice versa.
In connection with this definition it is also useful to consider what is
meant by transmission line and by resonator. A transmission line is a
device for transmitting or guiding radio-frequency energy from one point
to another. Usually it is desirable to transmit the energy with a minimum
of attenuation, heat and radiation losses being as small as possible. This
means that while the energy is being conveyed from one point to another it
is confined within the transmission line or to the vicinity of the line.
Thus, the wave transmitted along the line is one-dimensional in that it
does not spread out into space but follows along the line. From this
general point of view the term transmission line includes not only coaxial
and two-wire transmission lines but also hollow pipes, or wave guides.
A generator connected to an infinite, lossless transmission line produces
a uniform traveling wave along the line. If the line is short-circuited, a
standing wave appears because of interference between the incident and
reflected waves. A standing wave has associated with it local
concentrations of energy. If the reflected wave is equal to the incident
wave, we have a pure standing wave. The energy concentrations in such a
wave oscillate from entirely electric to entirely magnetic energy and back
twice per cycle. Such energy behavior is characteristic of a resonant
circuit, or resonator. Although the term resonator, in its most general
sense, may be applied to any device with standing waves, the term is
usually reserved for devices with stored energy concentrations that are
large compared with the inflow or outflow of energy.(2)

(2) The ratio of the energy stored to that lost per cycle is
proportional to the Q, or sharpness of resonance of the resonator."



From Wikipedia:

"In physics, power (symbol: P) is the rate at which work is performed or
energy is transmitted, or the amount of energy required or expended for a
given unit of time.
When the rate of energy transfer or work is constant, all of this can be
simplified to

P=W/t=E/t

where W and E are, respectively, the work done or energy transferred in
time t (usually measured in seconds)."


Yuri and W9UCW also found that
on a quarter wave resonant vertical antenna, which is a standing wave
circuit, and demonstrates that at the current maximum at the base, or at
the bottom of the loading coil, the current heats the wire. At the tip,
where there is a voltage maximum, the corona or neon bulb lights up. Both
effects demonstrating that there is power (energy over time) being
exhibited.
Kraus so effectively explains it in the introduction to his book, but the
"expertise" on this news group insists on otherwise - "no power in
standing wave circuit".

73 Yuri, K3BU.us

Since you are drawing power, by lighting a neon bulb, or by creating a
corona, or by heating a wire through current flow, it cannot be a standing
wave in the theoretical sense. It is possible to use perfect or ideal
components in a theoretical analysis, but real life tends to throw a spanner
in the works. In any real standing wave circuit there are power losses due
to radiation or resistance. The nearest one could come to the idealised
standing wave circuit is the current flow around a superconductor. The
current flows continuously until an outside influence such as a magnetic
field interrupts the flow. Depending on the circumstances, a physical
(magnetic) repulsive force may be generated or a feedback loop may develop
resulting in rapid temperature rise, loss of superconductive properties and
a rather loud bang as the circuit comes apart. Clearly power does flow in
all real life standing wave circuits.

Mike G0ULI