Thread: my SWR reading
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Old October 26th 07, 11:18 PM posted to rec.radio.amateur.antenna
Gene Fuller Gene Fuller is offline
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Default my SWR reading

Cecil Moore wrote:
Gene Fuller wrote:
If you ever come to the realization that there is a difference between
transient conditions and steady-state conditions, along with the
realization that standing waves are actually useful, ...


Please explain how those waves can exist without energy,
i.e. without joules/sec passing a point.

No waves of power needed, average or not.


Please stop doing that, Gene. You know that I don't believe
in "power waves". What you are trying to deny is that EM
waves contain energy that can be measured at a point in
joules/sec = watts. That argument just won't fly.


Cecil,

I did not say anything that denied that EM waves contain energy.

Where this entire controversy always gets hung up is the difference
between the traveling wave model where the waves go back and forth over
the entire length of the transmission line, and the standing wave model.
In the traveling wave model it is necessary for the wave energy to
traverse back and forth along the entire line. This leads to the
condition where energy is flowing in both directions at the same time at
any given point in the line. In the standing wave model the energy
simply sloshes back and forth within a single half-wave loop. No energy
collisions; no problems at all.

As I have said many times, these are mathematical representations, not
physical "reality". Neither is more correct than the other. No physical
measurement can tell the difference. But it is often useful to use the
most convenient model that does not carry unwanted artifacts and other
baggage.

Oh, by the way, it is not possible to measure energy at a point. Energy
has an extrinsic, not intrinsic, character. It would be educational to
read any good physics text to understand what energy really means and
how conservation of energy laws are constructed.

73,
Gene
W4SZ