In article , Cecil Moore
wrote:

Hi John, one important fact that some people would like to
forget is that the reflected wave can indeed be partitioned
from the forward wave.

Hello, and it would be more correct to say that the forward and reflected
waves are components of a standing wave.

However a circulator plus load resistor located at the source
will prevent reflected wave energy from being incident upon
the source and will heat up that load resistor in the process
proving that reflected waves are real and do contain energy.

Hmm. Don't quite get that. Say an RF voltage source is located at port A
of an ideal 3-port circulator designed for a system (characteristic)
impedance of Zo. A load of ZL terminates port B and a load of Zo is
attached to port C. Now, incident energy from the source at A is
transferred by circulator action to the load at port B. If ZL is not
equal to Zo then reflected energy from port B is transferred to port C
where it is dissipated in the port C termination. None of the reflected
energy originating from port B ever returns to port A in this ideal case
(circulator has infinite isolation). Sincerely,

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

Cecil Moore wrote:

Hi John, one important fact that some people would like to
forget is that the reflected wave can indeed be partitioned
from the forward wave. Some people on this newsgroup argue
that the forward wave and reflected wave are inseparable and
that reflected waves contain no rearward traveling energy.

However a circulator plus load resistor located at the source
will prevent reflected wave energy from being incident upon
the source and will heat up that load resistor in the process
proving that reflected waves are real and do contain energy.

Hi Cecil

How much energy is "in the reflected wave" without a circulator load
resistor?

73, ac6xg

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.

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

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

On Tue, 22 Aug 2006 17:28:01 GMT, Cecil Moore
wrote:


and the reflections from a complimentary impedance discontinuity

What is a "complimentary impedance discontinuity", or even a
"complementary impedance discontinuity" if you meant that?

Owen
--

"Owen Duffy" wrote in message
...
On Tue, 22 Aug 2006 17:28:01 GMT, Cecil Moore
wrote:


and the reflections from a complimentary impedance discontinuity

What is a "complimentary impedance discontinuity", or even a
"complementary impedance discontinuity" if you meant that?
=======================================
Owen,
For the benifit of innocent bystanders, he means the same magnitude
discontinuity with the opposite sign. But you knew that of course,
didn't you?

On the other hand, I'm not sure *I* have described it correctly. It
can best be described in terms of the reflection coefficient.

There are two reflections, of opposite signs, which do not occur at
exactly the same instant in TIME.

Whatever it is, Cecil is (im)perfectly correct.
----
Reg.

Owen Duffy wrote:
Cecil Moore wrote:
and the reflections from a complimentary impedance discontinuity

What is a "complimentary impedance discontinuity", or even a
"complementary impedance discontinuity" if you meant that?

Sorry about the misspelling. I was trying to us the word
"complement" in the sense of "A numerical derived from a
given numeral by a specified subtraction rule. Often used
to represent the negative of the number represented by the
given numeral." Definition from "The IEEE Dictionary".

For instance, the reflection coefficient at the second impedance
discontinuity can be considered to be the complement of the
reflection coefficient at the first impedance discontinuity.

--------Z01---x---Z02---y---Z01-----------

The physical reflection coefficient at point 'x' would be
(Z02-Z01)/(Z01+Z02). The physical reflection coefficient at point
'y' would be (Z01-Z02)/(Z01+Z02). Mathematically, those two
reflection coefficients can be considered to be complements of
each other.
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:
Reg Edwards wrote:

Regardless of its other dimensions, the primary requirement of a
mismatched connector is that its length should be appreciably less
than 1/4-wavelength at the highest working frequency.


Yes, at HF the reflections from one impedance discontinuity
and the reflections from a complimentary impedance discontinuity
3 inches away almost entirely cancel each other.

What's a "complimentary impedance discontinuity," Cecil?
73,
Tom Donaly, KA6RUH

Tom Donaly wrote:
What's a "complimentary impedance discontinuity," Cecil?

Sorry my spellchecker didn't catch that. It should have
been "complementary", a mathematical term. Please see
my reply to Owen.
--
73, Cecil http://www.qsl.net/w5dxp