On Jun 12, 9:17*pm, Cecil Moore wrote:
On Jun 12, 12:39*pm, K1TTT wrote:

i don't do s stuff so i have no idea what you just proved... give me
the impedances and voltages/currents.

Too bad about the "s stuff". Here are the RF equations for a Z01 to
Z02 impedance discontinuity in a transmission line. The forward
voltage on the Z01 side is Vfor1 and the reflected voltage from the
impedance discontinuity (back toward the source) is Vref1. The forward
voltage on the Z02 side is Vfor2 and the reflected voltage (from the
load) is Vref2. Hopefully, the reflection and transmission
coefficients are self-explanatory. rho1 is the reflection coefficient
encountered by Vfor1, etc.

Vref1 = Vfor1(rho1) + Vref2(tau2) = 0

That is wavefront cancellation in action. The external reflection
phasor, Vfor1(rho1), is equal in magnitude and 180 degrees out of
phase with the internal reflection phasor, Vref2(tau2), arriving from
the mismatched load.

Vfor2 = Vfor1(tau1) + Vref2(rho2)

If these RF equations are normalized to SQRT(Z0), they are the same as
the s-parameter equations.
--
73, Cecil, w5dxp.com

ok, so you defined a case where the superposition of the reflected and
refracted waves at a discontinuity results in a zero sum. is that
supposed to prove something? did i ever say that you could not define
such a case??

On Jun 12, 4:34*pm, K1TTT wrote:
ok, so you defined a case where the superposition of the reflected and
refracted waves at a discontinuity results in a zero sum. *is that
supposed to prove something? *did i ever say that you could not define
such a case??

I would call two waves superposing to zero indefinitely, "wave
cancellation". If that is not wave cancellation, where did the
reflected and refracted wavefronts go along with their energy
components? The answer to that question will reveal exactly what
happens to the reflected energy.

Here's a brain teaser for you and others. Given a Z01 to Z02 impedance
discontinuity with a power reflection coefficient of 0.25 at the '+'
discontinuity:

------Z01------+------Z02-------load

Pfor1 in the Z01 section is 100 watts. Pref1 in the Z01 section is
zero watts.

What is Pfor2, Pref2, and the SWR in the Z02 section?
--
73, Cecil, w5dxp.com

On Jun 13, 12:00*am, Cecil Moore wrote:
On Jun 12, 4:34*pm, K1TTT wrote:

ok, so you defined a case where the superposition of the reflected and
refracted waves at a discontinuity results in a zero sum. *is that
supposed to prove something? *did i ever say that you could not define
such a case??

I would call two waves superposing to zero indefinitely, "wave
cancellation". If that is not wave cancellation, where did the
reflected and refracted wavefronts go along with their energy
components? The answer to that question will reveal exactly what
happens to the reflected energy.

i don't care, i know that the superimposed voltage or current is
zero. from that i can calculate the power or energy anywhere i
want.

why does anyone care about 'energy' anyway, that is even worse to
think about in transmission lines than power. at least you can
measure, or at least calibrate your meters, in power units. have you
ever seen an amateur station that had an energy meter on their
transmitter? and isn't the term 'reflected energy' kind of an
oxymoron anyway? for energy to be reflected it has to be moving, so
isn't that just another word for power?



Here's a brain teaser for you and others. Given a Z01 to Z02 impedance
discontinuity with a power reflection coefficient of 0.25 at the '+'
discontinuity:

------Z01------+------Z02-------load

Pfor1 in the Z01 section is 100 watts. Pref1 in the Z01 section is
zero watts.

What is Pfor2, Pref2, and the SWR in the Z02 section?
--
73, Cecil, w5dxp.com

so? what does this special case prove that hundreds of others
doesn't?

On Jun 13, 5:35*am, K1TTT wrote:
On Jun 13, 12:00*am, Cecil Moore wrote:
The answer to that question will reveal exactly what
happens to the reflected energy.

i don't care, i know that the superimposed voltage or current is
zero. *from that i can calculate the power or energy anywhere i
want. why does anyone care about 'energy' anyway, ...

You get exactly the same answers doing it my way but my way yields the
additional information of exactly what happens to the energy
components. When two wavefronts superpose to zero indefinitely, I
would take that as proof of interaction and wave cancellation.

This is what invariably happens to the discussion. After being told
that I am absolutely wrong about energy flow, I introduce the known
laws of EM physics from the field of optics and prove that they
provide exactly the same answers as a conventional RF analysis. After
some discussion, it is asserted that the person (not only you) doesn't
care and it doesn't matter anyway. W7EL says in his food-for-thought
article, "I personally don’t have a compulsion to understand where
this power 'goes'."

A 1/4WL series matching stub is essentially the same function in
concept as a 1/4WL thin-film coating on non-reflective glass. How the
non-reflective glass works is perfectly understood and a 1/4WL series
matching section works the same way. Why not glean some knowledge from
the field of optics if it helps hams to understand "where the power
goes"? Optical physicists were forced to track power density from the
very start of their science because they didn't have the luxury of
tracking the voltage and current.

Here's a brain teaser for you and others. Given a Z01 to Z02 impedance
discontinuity with a power reflection coefficient of 0.25 at the '+'
discontinuity:

------Z01------+------Z02-------load

Pfor1 in the Z01 section is 100 watts. Pref1 in the Z01 section is
zero watts.

What is Pfor2, Pref2, and the SWR in the Z02 section?

so? *what does this special case prove that hundreds of others
doesn't?

The magnitudes of the voltages and currents in the above example are
indeterminate. Can you (or anyone else) solve the problem without
resorting to voltage and current calculations? I am just trying to get
people to think outside of their rigid concrete voltage/current boxes.
--
73, Cecil, w5dxp.com

On Jun 13, 2:04*pm, Cecil Moore wrote:
On Jun 13, 5:35*am, K1TTT wrote:

On Jun 13, 12:00*am, Cecil Moore wrote:
The answer to that question will reveal exactly what
happens to the reflected energy.

i don't care, i know that the superimposed voltage or current is
zero. *from that i can calculate the power or energy anywhere i
want. why does anyone care about 'energy' anyway, ...

You get exactly the same answers doing it my way but my way yields the
additional information of exactly what happens to the energy
components. When two wavefronts superpose to zero indefinitely, I
would take that as proof of interaction and wave cancellation.

This is what invariably happens to the discussion. After being told
that I am absolutely wrong about energy flow, I introduce the known
laws of EM physics from the field of optics and prove that they
provide exactly the same answers as a conventional RF analysis. After
some discussion, it is asserted that the person (not only you) doesn't
care and it doesn't matter anyway. W7EL says in his food-for-thought
article, "I personally don’t have a compulsion to understand where
this power 'goes'."

A 1/4WL series matching stub is essentially the same function in
concept as a 1/4WL thin-film coating on non-reflective glass. How the
non-reflective glass works is perfectly understood and a 1/4WL series
matching section works the same way. Why not glean some knowledge from
the field of optics if it helps hams to understand "where the power
goes"? Optical physicists were forced to track power density from the
very start of their science because they didn't have the luxury of
tracking the voltage and current.

Here's a brain teaser for you and others. Given a Z01 to Z02 impedance
discontinuity with a power reflection coefficient of 0.25 at the '+'
discontinuity:

------Z01------+------Z02-------load

Pfor1 in the Z01 section is 100 watts. Pref1 in the Z01 section is
zero watts.

What is Pfor2, Pref2, and the SWR in the Z02 section?

so? *what does this special case prove that hundreds of others
doesn't?

The magnitudes of the voltages and currents in the above example are
indeterminate. Can you (or anyone else) solve the problem without
resorting to voltage and current calculations? I am just trying to get
people to think outside of their rigid concrete voltage/current boxes.
--
73, Cecil, w5dxp.com

why are they indeterminate? i can calculate them, why can't you?

On Jun 13, 9:34*am, K1TTT wrote:
why are they (voltages) indeterminate? *i can calculate them, why can't you?

Purposefully, the numerical values of Z01 and Z02 are not given and
unknown. The answer to the problem would be the same if Z01=50 and
Z02=150, or if Z01=100 and Z02=300, or an infinite number of other
combinations. Please tell me how you can calculate an absolute voltage
when Z0 is an unknown variable?
--
73, Cecil, w5dxp.com

On Jun 13, 3:02*pm, Cecil Moore wrote:
On Jun 13, 9:34*am, K1TTT wrote:

why are they (voltages) indeterminate? *i can calculate them, why can't you?

Purposefully, the numerical values of Z01 and Z02 are not given and
unknown. The answer to the problem would be the same if Z01=50 and
Z02=150, or if Z01=100 and Z02=300, or an infinite number of other
combinations. Please tell me how you can calculate an absolute voltage
when Z0 is an unknown variable?
--
73, Cecil, w5dxp.com

the same way you calculate the power to be zero watts. no need to
know the z0 if the voltage is zero.

On Jun 13, 2:04*pm, Cecil Moore wrote:
On Jun 13, 5:35*am, K1TTT wrote:

On Jun 13, 12:00*am, Cecil Moore wrote:
The answer to that question will reveal exactly what
happens to the reflected energy.

i don't care, i know that the superimposed voltage or current is
zero. *from that i can calculate the power or energy anywhere i
want. why does anyone care about 'energy' anyway, ...

You get exactly the same answers doing it my way but my way yields the
additional information of exactly what happens to the energy
components. When two wavefronts superpose to zero indefinitely, I
would take that as proof of interaction and wave cancellation.

This is what invariably happens to the discussion. After being told
that I am absolutely wrong about energy flow, I introduce the known
laws of EM physics from the field of optics and prove that they
provide exactly the same answers as a conventional RF analysis. After
some discussion, it is asserted that the person (not only you) doesn't
care and it doesn't matter anyway. W7EL says in his food-for-thought
article, "I personally don’t have a compulsion to understand where
this power 'goes'."

hams 'know' where the power goes, their swr meter tells them it goes
back to the transmitter!

why don't physicists working in optics calculate fields? the electric
and magnetic field models work just as well at those frequencies as
they do on hf. indeed, why don't optical physicists learn something
from rf designers and model their thin films with transmission lines!

On Jun 13, 12:00*am, Cecil Moore wrote:
On Jun 12, 4:34*pm, K1TTT wrote:

ok, so you defined a case where the superposition of the reflected and
refracted waves at a discontinuity results in a zero sum. *is that
supposed to prove something? *did i ever say that you could not define
such a case??

I would call two waves superposing to zero indefinitely, "wave
cancellation". If that is not wave cancellation, where did the
reflected and refracted wavefronts go along with their energy
components? The answer to that question will reveal exactly what
happens to the reflected energy.

Here's a brain teaser for you and others. Given a Z01 to Z02 impedance
discontinuity with a power reflection coefficient of 0.25 at the '+'
discontinuity:

------Z01------+------Z02-------load

Pfor1 in the Z01 section is 100 watts. Pref1 in the Z01 section is
zero watts.

What is Pfor2, Pref2, and the SWR in the Z02 section?
--
73, Cecil, w5dxp.com

just for fun... explain why i can see that discontinuity between z01
and z02 when i hook up my tdr.

On Jun 13, 6:16*am, K1TTT wrote:
just for fun... explain why i can see that discontinuity between z01
and z02 when i hook up my tdr.

That's easy, because it *physically exists in reality* with a voltage
reflection coefficient of (Z02-Z01)/(Z02+Z01) = 0.5. It is related to
the indexes of refraction in the field of optics from which the same
reflection coefficient can be calculated.

The difficult question is: Exactly why doesn't that same physical
reflection coefficient reflect half of the forward voltage when it is
Z0-matched during steady-state?

The answer is that it indeed does reflect 1/2 of the forward voltage
during steady-state but that wavefront interacts with 1/2 of the
reflected voltage returning from the mismatched load which is equal in
magnitude and 180 degrees out of phase. In this case, superposition of
the two waves results in wave cancellation (total destructive
interference). The energy components in those two waves are combined
and redistributed back toward the load as constructive interference in
phase with the forward wave from the source. That's where the
reflected energy goes.

That's why the s-parameter analysis theory could be important to hams.
By merely measuring the four reflection/transmission coefficients
(s11, s12, s21, s22) one learns the basics of superposition. S-
parameter analysis was covered in my 1950's college textbook, "Fields
and Waves in Modern Radio", by Ramo and Whinnery (c)1944. I don't know
how or why the younger generation missed it.
--
73, Cecil, w5dxp.com