Tarmo Tammaru wrote:
Try this out. For a line driven by a sin wave, there is a lumped parameter
equivalent circuit with impedance R + JX for any line length and any
termination.

Yes, but that's ALL it is - just an equivalent circuit. "Equivalent"
doesn't mean equivalent radiation. "Equivalent" doesn't mean equivalent
forward and reflected waves. It ONLY means equivalent NET voltage and
equivalent NET current at a point. It is a shortcut. It does NOT effect
reality. Past the net voltage and net current point absolutely nothing
is equivalent.
--
73, Cecil http://www.qsl.net/w5dxp



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Ian White, G3SEK wrote:

W5DXP wrote:
Yes, but I comprehend what I am doing. For you to imply the "electrical
properties don't change" between a 50 ohm dummy load and a 50 ohm dipole
antenna is simply ridiculous.

I didn't either say that or imply it. What's truly "ridiculous" is for
you to *infer* that I did.

I didn't have to infer anything, Ian, those words in quotes are *your
quoted words*. Here they are again:

That whole principle relies on the fact that, at the same frequency
and in the steady state, the "definition of impedance" in terms of
its electrical properties does *not* change.

That certainly implies that there is no difference between the electrical
properties of the impedance of a 50 ohm dummy load and a 50 ohm antenna.
--
73, Cecil http://www.qsl.net/w5dxp



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Jim Kelley wrote:
Your
problem proves that your analysis and the notion of power flow are
flawed.

You haven't answered my question so you have not earned the right to
set up a new straw man. Why does Pref1 suddenly go to zero just as
Pref2 arrives at the impedance discontinuity?

As Timo and I have both said to you, it can be shown that that 50
joules/sec does not travel rearward.

You have not presented an iota of evidence that Pref2 does not travel
rearward. Half of that 50 joules/sec comes from rearward-traveling Pref2.
Sorry, until you address that contradiction in your concepts, you don't
have any creditability on this subject.

You have repeatedly refused to answer this simple question: How does
the energy in the reflected wave from the mismatched load get turned
around? We know it possesses momentum so it does turn around. What is
your physics mechanism for explaining the change in direction of
momentum of Pref2?

You have already admitted that wave cancellation is
responsible for Pref1 being zero.

"Admitted" is a funny word for it.

After months of denying it, you finally admitted it. Admitted seems
entirely appropriate.

When waves cease to exist, they are forced to give up their intrinsic energy.

Waves don't cease to exist.

That's where you are wrong. Waves cease to exist when they encounter a
matched dummy load, for instance. Waves also cease to exist when they
are destroyed by wave cancellation. Light waves cease to exist when they
encounter a perfectly flat black surface. Your assertion is false.
--
73, Cecil http://www.qsl.net/w5dxp



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W5DXP wrote:

Jim Kelley wrote:
Your
problem proves that your analysis and the notion of power flow are
flawed.

You haven't answered my question so you have not earned the right to
set up a new straw man. Why does Pref1 suddenly go to zero just as
Pref2 arrives at the impedance discontinuity?

Has wave cancellation suddenly become a point of contention?

Your latest example obviously shows the weakness in your argument.

As Timo and I have both said to you, it can be shown that that 50
joules/sec does not travel rearward.

You have not presented an iota of evidence that Pref2 does not travel
rearward.

The absence of any evidence that it does presents a more formidable
problem, in my opinion.

You have repeatedly refused to answer this simple question: How does
the energy in the reflected wave from the mismatched load get turned
around?

That's a lie, and everyone here knows it. I've answered the question
every time it was posed. Timo answer it the same way I have. Energy
does not get turned around - it never flows to the left of the
discontinuity.

We know it possesses momentum so it does turn around.

Must be the Royal 'we'.

What is
your physics mechanism for explaining the change in direction of
momentum of Pref2?

What reason can you provide for continuing to beat your neice?

You have already admitted that wave cancellation is
responsible for Pref1 being zero.

"Admitted" is a funny word for it.

After months of denying it, you finally admitted it. Admitted seems
entirely appropriate.

That's an absolute fabrication. Revisionist history. I was the one who
INSISTED that no power ever flowed back from the discontinuity. In fact
you argued with me about it. You've got a major mental glich happening
there, Cecil.

Waves cease to exist when they encounter a
matched dummy load, for instance.

The wave is transformed at a load. It doesn't simply "cease to exist".
But I can see this is leading to another of your symantics arguments.
You could avoid them in the future by using convention terminology. But
I doubt you really want to avoid them. Seems they're the 'secret
weapon' of the newsgroup warrior.

73, ac6xg

Cecil begs to differ:

The electrical properties *can* change and that's the whole point. The
electrical properties of a 50+j0 dummy load and a 50+j0 antenna are
almost completely different.


Like what, as far as the source and feedline are concerned?
Ain't that basically "AC" RF power being produced by the TX, flowing through
the transmission line, to 50+j0? (Resistance/impedance)
Who gives the hoot if that 50+j0 is power eating resistor or power barfing
antenna. Call it virtual(y) non-radiating antenna or virtual(y) radiating
resistor. Simply transducers looking pretty to the feedline and doing their
assigned thing. F the SWR, matchit !
RIP

BUm

W5DXP wrote:

There are many more faith-based characteristics of the steady-state model.

Actually, the steady state "model" describes the observable aspects of
the phenomenon. According to a least one theorist, physics is a science
of measurement. Science is of course a study of observable phenomena.

73, AC6XG

W5DXP wrote:

Jim Kelley wrote:

W5DXP wrote:
Has wave cancellation suddenly become a point of contention?

It was our point of contention for months. Finally, you relented.

It's been my impression that wave cancellation and interference has
always been the one thing we've agreed upon.

Your latest example obviously shows the weakness in your argument.

It obviously shows the strength of my argument since you avoid
discussing it at all costs. :-)

If I wasn't discussing it, you obviously wouldn't have had anything to
post reply comments about. That your numbers are the same in two
scenarios, each involving a different input power level perfectly
illustrates your misinterpretion of the meaning of the numbers.

I've answered the question every time it was posed.

But your "answer" is always a bogus non-answer, an empty mantra.

So now you agree that I've answered the question. The fact you disagree
with the answer is irrelevant to that point.

Energy does not get turned around - it never
flows to the left of the discontinuity.

According to Ramo & Whinnery, reflected energy does indeed flow
rearward from a mismatched load. That reflected energy possesses
momentum in the rearward direction and changes direction at the
impedance discontinuity. You still have not offered an acceptable
explanation for that energy and momentum turn around.

Apparently, neither have Ramo & Whinnery. But that's understandable,
given that the idea is entirely your invention.

What reason can you provide for continuing to beat your neice?

Your only response is a diversion. That speaks volumes.

It speaks Cecilian, actually. You didn't notice the similarity in
technique? It was a response in kind to the exact form of the question
you asked.

I was the one who
INSISTED that no power ever flowed back from the discontinuity. In fact
you argued with me about it.

I NEVER argued with you about that.

I cannot recall a single instance of you ever agreeing with anything
I've written on the subject - including (V3 + V4) * (I3 + I4) = 0,
and P3+P4-(2*SQRT(P3*P4)=0. That's wave cancellation my friend, and I
posted these things at the beginning of this discussion. You've always
argued with the validity of these equations.

It was a mistake to try again to be civil to you.

When did that happen?

The wave is transformed at a load. It doesn't simply "cease to exist".

The energy in the wave is transformed from RF to heat by the dummy
load. The RF wave certainly does cease to exist.

As I said, we're now in an argument over semantics caused by your
creative use of terminology. "Cease to exist" in any case implies
something which isn't true.

But back to the point, for what amount of time do the cancelled waves
"exist" in order that they might then be able to "cease to exist"? If
you say during the transient period between T0 and steady-state, then
we're in agreement.

73, Jim AC6XG

Yuri Blanarovich wrote:
Who gives the hoot if that 50+j0 is power eating resistor or power barfing
antenna.
1
You don't care whether all your power is going into a dummy
load or into your antenna?
2
We are trying to figure out something about transmission lines
so we take away the transmission line and replace it with an
"equivalent circuit" that doesn't act like a transmission at all?
How in the world does that tell us anything about transmission
lines?
--
73, Cecil, W5DXP

1
Am I getting sucked into the bottomless black hole of transmission lines?
Yea, I care! If I want to test or tune my transmitter or amplifier and need a
dummy, I use dummy load. When I need to radiate killer signals I use my Razor
beams, but they are designed to have 50 ohm impedance and broad bandwidth
(possible, been there, done it) no matching crap, no reflections (ok very
small) and I don't give a Freak about nurturing reflections on the line. I hate
reflected waves and I suppress their generation/reflection/travel and endless
discussions about problem that nobody wants.

2
Huh? You haven't figured that SWR is bad for transmission lines?
All I want to know about transmission line that it doesn't have impedance
bumps, keeps its impedance, that it has lowest possible loss and doesn't
radiate or let the water in. (That goes for open wire feeders too :-)
Oh, color doesn't matter and it should be repulsive to chipmunks and other SWR
ignorant critters.
Why is this endless argument about reflections going on? We know they are bad,
we know how to eliminate them, so what's the problem? You love them so much
that you want to keep them in your coax?
There are no reflections around this shack, only in the mirror of my ugly face
after 48 hr contest.
OK hit me now that it is impossible to have reflectionless antenna-coax-tx.
My answer, yea, there are some (very little) and they are insignificant to me
to worry about and lose sleep and hours at the keyboard. Ins't it like eunuch
dreaming about sex? :-)

SK
73 Yuri da noSWR BUm

Jim Kelley wrote:

W5DXP wrote:
Has wave cancellation suddenly become a point of contention?

It was our point of contention for months. Finally, you relented.

Your latest example obviously shows the weakness in your argument.

It obviously shows the strength of my argument since you avoid
discussing it at all costs. :-)

You have not presented an iota of evidence that Pref2 does not travel
rearward.

The absence of any evidence that it does presents a more formidable
problem, in my opinion.

I quoted the evidence from Ramo & Whinnery. You just ignored it.

I've answered the question every time it was posed.

But your "answer" is always a bogus non-answer, an empty mantra.

Energy does not get turned around - it never
flows to the left of the discontinuity.

According to Ramo & Whinnery, reflected energy does indeed flow
rearward from a mismatched load. That reflected energy possesses
momentum in the rearward direction and changes direction at the
impedance discontinuity. You still have not offered an acceptable
explanation for that energy and momentum turn around.

What reason can you provide for continuing to beat your neice?

Your only response is a diversion. That speaks volumes.

I was the one who
INSISTED that no power ever flowed back from the discontinuity. In fact
you argued with me about it.

I NEVER argued with you about that. You are back to your lying ways.
I would NEVER argue with a Bird wattmeter? You obviously have me
confused with Dr. Best. In fact, I published part of my article
saying that everything takes place at exactly the impedance discontinuity
and nowhere else. Having to lie about what I have said is just proof of
the weakness of your argument.

I'm sorry, Jim. I refuse to engage in a discussion at your chosen ethical
and moral level. It was a mistake to try again to be civil to you.

The wave is transformed at a load. It doesn't simply "cease to exist".

The energy in the wave is transformed from RF to heat by the dummy
load. The RF wave certainly does cease to exist. You're not back to
your phantom waves that last forever without a source of energy, are
you?
--
73, Cecil, W5DXP

Yuri Blanarovich wrote:
Who gives the hoot if that 50+j0 is power eating resistor or power barfing
antenna.

You don't care whether all your power is going into a dummy
load or into your antenna?

We are trying to figure out something about transmission lines
so we take away the transmission line and replace it with an
"equivalent circuit" that doesn't act like a transmission at all?
How in the world does that tell us anything about transmission
lines?
--
73, Cecil, W5DXP