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Mismatched Zo Connectors

Gene Fuller wrote:
If you refuse to accept standard technical conventions, then there is
little hope of getting others to agree with you.

Gene, have you stopped beating your wife? Your usual ad
hominem attack completely devoid of any technical content
is duly noted.

In a one second long lossless transmission line where the
forward power is 200W and the reflected power is 100W, it
can be proved that the source has supplied 300 joules that
have not been accepted by the load. If those joules are not
contained in the forward and reflected waves, where are they?
--
73, Cecil http://www.qsl.net/w5dxp

Mismatched Zo Connectors

Gene Fuller wrote:
If you refuse to accept standard technical conventions, then there is
little hope of getting others to agree with you.

I am advocating the wave reflection model as explained in:

Johnson's, "Transmission Lines and Networks", 1st Edition

Ramo/Whinnery's, "Fields and Waves in Modern Radio", 2nd Edition

Hecht's, "Optics", 4th Edition

Maxwell's, "Reflections" and "Reflections II"

"The ARRL Antenna Book", 15th Edition

I am also advocating the conservation of energy principle.
I hope that one doesn't need references.

Exactly what is it about the wave reflection model and the
conservation of energy principle with which you disagree?
--
73, Cecil http://www.qsl.net/w5dxp

Mismatched Zo Connectors

John,

I would like to reply to your question (if that's what it is) but I am
unable to understand what you are saying.

So I leave it to Cecil and Co. to add further to the complications and
confusion.

It's really all very simple.
----
Reg.

Mismatched Zo Connectors

In article , "Reg Edwards"
g4fgq,regp@ZZZbtinternet,com wrote:

John,

I would like to reply to your question (if that's what it is) but I am
unable to understand what you are saying.

So I leave it to Cecil and Co. to add further to the complications and
confusion.

It's really all very simple.
----
Reg.

Hello, Reg. What I didn't understand was your statement "Reflections are
functions of TIME, not frequency." That statement immediately invited
conflict with the info contained in my electromagnetics and transmission
line theory texts lining my office bookshelf. I attempted to provide some
clarification and hopefully not insult anyone's intelligence. Sincerely,

John Wood (Code 5550) e-mail:
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337

Mismatched Zo Connectors

Reg Edwards wrote:
So I leave it to Cecil and Co. to add further to the complications and
confusion.

Reg, how about these statements from a recent QEX article?

"Contrary to popular views, the forward and reverse
waves on a transmission line are not separate fields."
"I wish to emphasize the fact that the forward and
reverse waves really do not exist separately, ..."
"Dual Directional Wattmeters", Eric von Valtier, K8LV,
_QEX_, May/June 2006.

The article obviously rejects the wave reflection model
for transmission lines as presented by Ramo/Whinnery,
Johnson, etc.

If forward and reverse waves do not exist separately,
how is it possible for a circulator to separate them?
--
73, Cecil http://www.qsl.net/w5dxp

Mismatched Zo Connectors

Cecil,

I think you are conflating models with nature, and trying to champion
one correct model over another correct model! It's confusing to
onlookers and boring.

There is NO inconsistency between saying "there's only one
electromagnetic field in a transmission line" and "a circulator
seperates the forward wave from the reflected wave" if you've suitably
defined what all those terms mean and you do the correct math.

The electromagnetic field as a function of space and time in the
coaxial transmission line is a three-dimensional time dependent field.
There's a description wherein one single vector valued function
E(r,phi,z, t) describes the electric field and another describes the
magnetic field, and of course, you can get one from the other, so in
some sense, all you need to describe what's going on is E(r,phi,z,t).

Now, in the coaxial TEM mode the radial and azimuthal dependence of the
fields becomes trivial, and you're just left with some function E'(z,t)
to describe the electric field, and one B'(z,t) for the magnetic field
(once again, you can of course, get one from the other) It turns out
that mathematically you can represent this function as a superposition
of other functions, forward and reverse traveling waves. It's just a
DIFFERENT WAY OF WRITING IT DOWN.

A circulator *doesn't know math*. Its operation may have a simple
description in the language of forward and reverse waves, but it does
what it does no matter what model you use to describe it. If you get
different answers using a forward and reflected wave description than
some other description, then one or both of your descriptions are
wrong. The conversion of one mathematical description of the
electromagnetic field into a series of statements in English and the
argument based on those words never gets you anywhere on this topic.
Why not pick up a copy of Jackson's Electrodynamics and write down what
you're trying to say mathematically. If you're right, everyone will
have to be convinced.

73,
Dan

Mismatched Zo Connectors

The fundamental partial differential equations of transmission lines
are -

- dv/dz = R + L*di/dz

- di/dz = G + C*dv/dz

where volts v and current i are incremental functions of distance and
time, and z is incremental distance along line.

Everything else follows.

Similar equations can be written in terms of frequency.

It is often easier to think in terms of Time and Distance rather than
Frequency and Impedance.
----
Reg.

Mismatched Zo Connectors

"Cecil Moore" wrote
If forward and reverse waves do not exist separately,
how is it possible for a circulator to separate them?

=========================================
Cec,

You forgot to allow TIME into the argument.

The two waves do NOT, and cannot, exist seperately in time.

The circulator merely divides the STEADY STATE, instantaneous, at the
same time, power in the wave into two parts according to what the
operator, or by design, has set it to do.

When the generator is switched off both parts disappear
simultaneously.

I know this won't satisfy you.
----
Reg.