Keith wrote:
"Is it step 7)?"

"7) From 6), the energy crossing quarter wave points is zero"

False, as are several other of Keith`s speculations.

Standing waves throughout a long transmission line with a hard short or
open-circuit at its end are proof enough that SWR nulls other than the
one at the actual discontinuity don`t bring the energy crossing 1/4-wave
points to zero. SWR nulls other than the one at the actual open or short
have no effect on traveling waves, absent an additional actual
discontinuity. SWR can`t exist without energy flow in both directions.
Energy flow is continuous. It doesn`t start and stop at SWR nulls. This
continuity is proved by measurements at the nulls, taken in one
direction at a time.

No speculation or even math is needed to observe this behavior on an
actual line. It is usless to try to conform the observable to some
theory. It is far more productive to conform theory to the observable.

Best regards, Richard Harrison, KB5WZI

Richard Harrison wrote:

Keith wrote:
"Is it step 7)?"

"7) From 6), the energy crossing quarter wave points is zero"

False, as are several other of Keith`s speculations.

I do not see any flaw in step 7).

Assuming that step 6)
"6) From 2) and 5), the power (rate of energy flowing) at quarter
wave points will be 0"
is correct, then step 7)
"7) From 6), the energy crossing quarter wave points is 0"
must also be true, since,

If the rate of energy flowing is zero, then there is no energy
flowing so there can not be any energy crossing the point.

I do not find that step 7) is in error.

If there is an error in the final conclusion then I do not think
that it is an error in step 7) which causes the final error,
but, rather, the error must be in one of the earlier steps.

....Keith

wrote:
I do not see any flaw in step 7).

Try opening your eyes.

If the rate of energy flowing is zero, then there is no energy
flowing so there can not be any energy crossing the point.

There is no NET energy flow. There is plenty of component energy
flow as defined by Ramo & Whinnery's forward Poynting vector and
reflected Poynting vector. Why do you continue to ignore those
vectors? Why do you continue to ignore the wealth of knowledge
contained in light interference patterns?
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

What is missing here, IMO, is that the physics of energy flow has not
been adequately explained. Cecil provided a reference to it but did not
elaborate for the general readership.

The energy in forward and reflected waves has been well documented for
many years. From Kraus, Electromagnetics, McGraw Hill, 1953, Chapter 9,
Section 9-13, "Energy Relations in a Standing Wave":

EQ 9-145 We = 2eEo^2[cos^2wt*sin^2Bx]

EQ 9-147 Wm = 2uHo^2[sin^2wt*cos^2Bx]

Note: The energy in the E field [We] is a function of the sin^2(Bx).
The energy in the H field [Wm] is a function of the cos^2(Bx).

You will remember from trigonometry the the maxima [or minima] of a sin
and cos are displaced by 90 degrees. Conclusion: when the E field is
zero the H field is maximum; when the H field is zero the E field is
maximum. Ergo! Energy is conserved and propagates through the zero E
field as an H field; also, when the H field is zero the energy is in the
E field. This is what Cecil is referring to when he refers to the
Poynting vector.

It is analogous to a parallel tuned circuit. When the instantaneous
voltage across the capacitor is zero we don't claim there is no energy
in the circuit. We know that the energy is stored in the inductor.
Conversely, when the instantaneous current in the inductor is zero we
don't claim there is no energy in the circuit. We know the energy is
stored in the capacitor.

In a TEM wave the energy cycles between the E field and the H field and
the energy components are 90 degrees out of phase.

Deacon Dave, W1MCE

Keith wrote:
"I do not find that step 7) is in error."

Step 7) declares power is zero at quarter wave points where volts or
amps are zero in the standing wave pattern.

Power flow does not stop at an actual short or open in a line. It merely
changes direction. At zero volt or amp points, where there is no actual
short or open, no reversal of direction occurs. Power flow is affected
in no way by standing wave nulls or maxima where no impedance
discontinuity exists.

Energy exists in every SWR null. It is in the two waves which produce
the null as these experience no change in energy due to standing waves.

Best regards, Richard Harrison, KB5WZI

Richard Harrison wrote:

Keith wrote:
"I do not find that step 7) is in error."

Step 7) declares power is zero at quarter wave points where volts or
amps are zero in the standing wave pattern.

Unfortunately, probably due to my poor description, you have missed
the point I was trying to make.

You are, I think, disagreeing with the RESULT of step 7.

Even though the result may be wrong, step 7) can be correct.

Step 7) again:
"7) From 6), the energy crossing quarter wave points is 0"

This is saying that if the result of step 6) is correct, then
the result of step 7) is correct. The transformation from 6)
to 7) merely integrated power to get energy; a common and
correct thing to do.

So if you disagree with the result of step 7), it is in step 6)
which you must search for the error since step 7) is correct.

If step 6) is correct, then search in step 2) and step 5) for
the error.

I suspect that like Cecil, you will end up at step 2) as the
source of what you perceive to be an error.

Then, when we resolve whether 2) is in error, we will know
whether the result of 7) is in error.

....Keith

wrote:
I suspect that like Cecil, you will end up at step 2) as the
source of what you perceive to be an error.

Which step the error is in depends upon whether you are talking
about NET energy or the forward and reflected component energies.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----