Cecil Moore wrote:
On Mar 13, 2:48 pm, Gene Fuller wrote:
No one denies the existence of reflections.

But some people deny that there is any energy in the reflections -
see below. :-)


But a big argument is about the
round-trip travel of energy in the steady-state. Some people seem to
believe that energy continues to flow back and forth from one end of a
(mismatched) transmission line to the other under steady-state
conditions, even simultaneously traveling in both directions. (Passing
like ships in the night?) Since energy is a scalar quantity, and any
given joule is not distinguishable from another, it is not clear how the
proponents keep track of the bookkeeping, but they muddle through somehow.

Again Gene, to be able to prove your point, you need to present an
example of a standing wave that exists without a forward traveling
energy wave and a reverse traveling energy wave. You keep implying
that is possible, but have presented no proof.

Au contraire, mon frere. You continue to claim that a standing wave MUST
be made up of two traveling waves, but without proof.

My contention is that this distinction is merely a matter of
mathematical preference. When standing waves occur, there is absolutely
no physical difference between the standing wave and its traveling wave
constituents. If you find some physically significant difference due to
considering traveling wave constituents rather than the standing wave,
then you have made a mistake in your calculations.

Water is also a scalar. If you had one gallon per minute flowing into
a barrel and two gallons per minute flowing out of the barrel, would
you argue that there is no water flowing into the barrel and only one
gallon of water flowing out of the barrel? Or would you say the *net*
water flow is one barrel per minute out of the barrel?

This is totally irrelevant to the issue at hand. Try to keep on task.

73,
Gene
W4SZ

On Mar 14, 12:24 pm, Gene Fuller wrote:
Au contraire, mon frere. You continue to claim that a standing wave MUST
be made up of two traveling waves, but without proof.

On the contrary, I have presented at least three references as proof.
If I remember correctly, it was Ramo, Whinnery, Hecht, and Balanis.
You, OTOH, have presented none.

My contention is that this distinction is merely a matter of
mathematical preference. When standing waves occur, there is absolutely
no physical difference between the standing wave and its traveling wave
constituents.

Obviously false as proven by the different equations for the two types
of waves. We laid that one to rest long ago. In fact, it was you who
pointed out that standing wave phase is completely different from
traveling wave phase and cannot be used to measure phase shift through
a coil. If I remember correctly, it was the difference between
cos(x*wt) and cos(x)*cos(wt), i.e. *very* different.

Water is also a scalar. If you had one gallon per minute flowing into
a barrel and two gallons per minute flowing out of the barrel, would
you argue that there is no water flowing into the barrel and only one
gallon of water flowing out of the barrel? Or would you say the *net*
water flow is one barrel per minute out of the barrel?

This is totally irrelevant to the issue at hand. Try to keep on task.

No, it is virtually identical to your argument. Saying it is "totally
irrevelent" doesn't change anything. You are arguing that net energy
transfer is primary and the underlying energy components are
irrelevant if nonexistant.
--
73, Cecil, w5dxp.com

Cecil Moore wrote:
On Mar 14, 12:24 pm, Gene Fuller wrote:
Au contraire, mon frere. You continue to claim that a standing wave MUST
be made up of two traveling waves, but without proof.

On the contrary, I have presented at least three references as proof.
If I remember correctly, it was Ramo, Whinnery, Hecht, and Balanis.
You, OTOH, have presented none.

My contention is that this distinction is merely a matter of
mathematical preference. When standing waves occur, there is absolutely
no physical difference between the standing wave and its traveling wave
constituents.

Obviously false as proven by the different equations for the two types
of waves. We laid that one to rest long ago. In fact, it was you who
pointed out that standing wave phase is completely different from
traveling wave phase and cannot be used to measure phase shift through
a coil. If I remember correctly, it was the difference between
cos(x*wt) and cos(x)*cos(wt), i.e. *very* different.

Water is also a scalar. If you had one gallon per minute flowing into
a barrel and two gallons per minute flowing out of the barrel, would
you argue that there is no water flowing into the barrel and only one
gallon of water flowing out of the barrel? Or would you say the *net*
water flow is one barrel per minute out of the barrel?
This is totally irrelevant to the issue at hand. Try to keep on task.

No, it is virtually identical to your argument. Saying it is "totally
irrevelent" doesn't change anything. You are arguing that net energy
transfer is primary and the underlying energy components are
irrelevant if nonexistant.
--
73, Cecil, w5dxp.com


Cecil,

Until next time. I guess we will continue to disagree.

73,
Gene
W4SZ

Gene Fuller wrote:
Until next time. I guess we will continue to disagree.

Gene, how can you insist that standing waves are just
like traveling waves when their equations are so
different - different enough to make them virtually
opposites. The phase of a traveling wave varies with
distance - the phase of a standing wave doesn't. The
amplitude of a standing wave varies with distance -
the amplitude of a traveling wave doesn't (in a loss-
less transmission line). I can't think of a way that
those two types of waves are alike except for frequency.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Gene Fuller wrote:
Until next time. I guess we will continue to disagree.

Gene, how can you insist that standing waves are just
like traveling waves when their equations are so
different - different enough to make them virtually
opposites. The phase of a traveling wave varies with
distance - the phase of a standing wave doesn't. The
amplitude of a standing wave varies with distance -
the amplitude of a traveling wave doesn't (in a loss-
less transmission line). I can't think of a way that
those two types of waves are alike except for frequency.

Cecil,

OK, so you don't want to let this drop quite yet. I have dredged through
the muck of Google archives, and I found the following 5 exact quotes
from you. I believe these fairly represent your position, but if not,
please let me know about others. More on the other end . . .

******************

1) Quoting Balanis: "Standing wave antennas, such as the dipole, can be
analyzed as traveling wave antennas with waves propagating in opposite
directions (forward and backward) and represented by traveling wave
antenna currents I(f) and I(b)."

2) Kraus: "A sinusoidal current distribution may be regarded as the
standing wave produced by two uniform (unattenuated) traveling waves of
equal amplitude moving in opposite directions along the antenna."

3) From "Fields and Waves ...", by Ramo & Whinnery, in describing the
standing wave situation: "The total energy in any length of line a
multiple of a quarter wavelength long is constant, *merely interchanging
between energy in the electric field of the voltages and energy in the
magnetic field of the currents*." Again, proof that standing wave energy
doesn't flow. It just stands there being exchanged between the E-fields
and the H-fields. That is from page 40 of "Fields and Waves in
Communications Electronics", by Ramo, Whinnery, and Van Duzer.

4) I recognize that equation from "Optics", by Hecht. Pick any point,
'z', and see what you get. Hecht says, "It doesn't rotate at all, and
the resultant wave it represents *DOESN'T PROGRESS THROUGH SPACE* - it's
a standing wave." The RF equivalent of a standing wave of light that
doesn't progress through space is an RF standing wave that doesn't
progress through a wire. That's what I have been telling you guys.
Standing waves don't move. Standing wave current doesn't flow! Even in
empty space, a light standing wave doesn't progress through space, i.e.
IT DOESN'T MOVE! That is on page 289 of "Optics", by Hecht, 4th edition.

5) Here's a little help from Hecht of "Optics" fame. (quote)

E(x,t)=2E0t*sin(kx)*cos(wt)

This is the equation for a *standing wave*, as opposed to a traveling
wave. Its profile does not move through space; it is clearly not of the
(traveling wave) form f(x +/- vt) ...
Let the phasor E1 represent a (traveling) wave to the left, and E2 a
(traveling) wave to the right. ... (The sum) doesn't rotate at all, and
the resultant wave it represents doesn't progress through space - it's a
standing wave. (end quote)

******************

Quotes (1) and (2) do not use words that most people would associate
with "proof". Instead, the use of terms such as "can be analyzed" and
"may be regarded" completely support my position that the choice to use
standing waves or traveling waves is simply one of mathematical
convenience. When standing waves exist, there is no physical difference
between the standing waves and their constituent traveling wave components.

Quotes (3), (4), and (5) completely support my position again. When a
standing wave exists, there is no more hidden information buried in the
constituent traveling wave components. No flowing energy waves or other
such nonsense.

It is possible to have many mathematical descriptions of a physical
phenomenon. However, they all need to yield exactly the same physical
predictions or else one or more of the models are incomplete or wrong.

Of course there are traveling waves that are not simply mathematical
components of standing waves. All of the stuff about TDRs and ghosts
falls into that category. This message is not about those traveling
waves at all, so you can forget about bringing up all of your TV ghost
arguments.

73,
Gene
W4SZ

Gene Fuller wrote:

Quotes (1) and (2) do not use words that most people would associate
with "proof". Instead, the use of terms such as "can be analyzed" and
"may be regarded" completely support my position that the choice to use
standing waves or traveling waves is simply one of mathematical
convenience.

No technical author is going to be arrogant enough to use
the phrases "must be analyzed" or "must be regarded". Many
shortcuts do work from a mathematical standpoint but often
lose their ability to tell us anything about reality.

You were the first person to point that out - that when two
opposite direction traveling waves are superposed, the sum
of the superposition loses its changing phase. That's why
W7EL's and W8JI's phase measurements through a loading coil
on a standing wave antenna were of no value except to prove
that standing wave current doesn't change phase in a wire or
in a coil.

When standing waves exist, there is no physical difference
between the standing waves and their constituent traveling wave components.

Proven false by the previous quote from "Optics", by Hecht.

E(x,t)=2E0t*sin(kx)*cos(wt)

This is the equation for a *standing wave*, as opposed to a traveling
wave. Its profile does *NOT* move through space; it is clearly *NOT*
of the
(traveling wave) form f(x +/- vt) ...

Hecht apparently assumed the definition of the word "not" is
understood by the average reader and didn't need emphasis
so I added it. :-)

There is an obvious physical difference that can be seen
from the equations. Again, a standing wave has fixed phase
while a traveling wave has a variable phase. A standing
wave has a variable amplitude while a traveling wave has
a fixed amplitude. That's two ways they are entirely
different.

No flowing energy waves or other such nonsense.

Nothing like that assertion is supported in the quotes. Please
point out where any of those references assert that there is no
energy in a reflected wave or that reflected waves do not exist.

Ramo and Whinnery go so far as to vector sum the forward power
flow vector and the reflected power flow vector.

It is possible to have many mathematical descriptions of a physical
phenomenon. However, they all need to yield exactly the same physical
predictions or else one or more of the models are incomplete or wrong.

Plus they need to be linked to reality. Standing waves existing
without the component forward and reverse traveling waves is
divorced from reality. Neither you nor anyone else has been able
to provide even one real-world example of such.

Forward traveling wave + reflected traveling wave = standing wave

What happens to the standing wave when you take away the reflected
wave?

Forward traveling wave + nothing = forward traveling wave

i.e. there is no standing wave. So please tell us again how
you can build a standing wave from a single traveling wave.

... so you can forget about bringing up all of your TV ghost
arguments.

That rug of yours under which you try to sweep all the
reflected energy is going to explode one of these days. :-)
--
73, Cecil, w5dxp.com

Cecil Moore wrote:


Forward traveling wave + reflected traveling wave = standing wave

What happens to the standing wave when you take away the reflected
wave?

It's a different physical situation. None of this discussion has any
bearing on the new problem with only one traveling wave. When you when
finally understand the meaning of your own words, there may be hope for
progress. Until then, we are just boring everyone.

73,
Gene
W4SZ

Cecil Moore wrote:


No technical author is going to be arrogant enough to use
the phrases "must be analyzed" or "must be regarded". Many
shortcuts do work from a mathematical standpoint but often
lose their ability to tell us anything about reality.


Cecil,

Utter rot. These experts are not careless. Textbooks are full of
examples of "must" and "may". The words are not chosen at random.

If you think a standing wave is a "shortcut", how about showing the
mathematical models that support your position? I, along with many
others, have shown the reverse many times.

73,
Gene
W4SZ

"Cecil Moore" wrote

Plus they need to be linked to reality. Standing waves existing
without the component forward and reverse traveling waves is
divorced from reality. Neither you nor anyone else has been able
to provide even one real-world example of such.

Forward traveling wave + reflected traveling wave = standing wave

What happens to the standing wave when you take away the reflected
wave?

Forward traveling wave + nothing = forward traveling wave

i.e. there is no standing wave. So please tell us again how
you can build a standing wave from a single traveling wave.

... so you can forget about bringing up all of your TV ghost arguments.

That rug of yours under which you try to sweep all the
reflected energy is going to explode one of these days. :-)
--
73, Cecil, w5dxp.com

Which brings us back to the great loading coil dispute.

In the resonant quarter wave monopole (say 80m), loaded with solenoid coil,
about 2/3 up the radiator, we experience significant (about 40%) current
drop at the top end of the coil. This is also demonstrated by bottom of the
coil getting warmer or hot proportionately, indicating that we have standing
wave circuit and some real current in the system, fortifying Cecil's
argument. RF is flowing along the radiator, "seeing" high impedance tip at
the end, being reflected, flowing back and being superimposed with the
forward wave. Reality that W8JI and other "defenders" had hard time to
swallow.

In the case of traveling wave antenna, like Beverage, terminated with
resistance, we can see the uniform current along the wire. Coil or slinky
inserted in such system will show the same current along the coil (minus
ohmic losses).

There is real life proof about what Cecil is saying above.

Relating to the standing wave circuit, I had question in my mind: how
important is to control the resistance and consider it in standing wave
antenna system. Example is that the current above the loading coil is
appreciably smaller than at the base, hinting that you perhaps do not need
low resistance (copper tubing vs. SS whip).

But...
if the standing wave is made of forward and reverse traveling waves, should
not we be trying to keep the resistance low in the system? Or is it
insignificant?
My pet peeve tells me that it would gain significance in the multi element
loaded arrays. Do the modeling programs capture that? They show slight
increase of current at the bottom (few turns) of the coil (when loading
inductance is properly modeled). Would that be due to the loss from that
point on, when forward and reflected wave is "meeting" the losses to
resistance and radiation and then with lesser amplitude superimposing with
forward wave?

Yuri, K3BU.us