On Fri, 12 Mar 2004 13:08:20 -0600, Cecil Moore
wrote:

We are past discussing reflections. The present argument is: Given two
coherent waves traveling in the same path with the same magnitude and
opposite phases, wave cancellation results from destructive interference.

The laws of physics tells us that energy cannot be destroyed and if
destructive interference exists, an equal magnitude of constructive
interference is required to exist. The destructive interference in
a Z0-matched system is toward the source. The constructive interference
in a Z0-matched system is toward the load. The energy components involved
in those two types of interference are traveling in opposite directions.

The conclusion is obvious. The reflected energy involved in the wave
cancellation process heads back toward the load just as explained on
the Melles-Griot web page. That there is such a large well-organized
good old boy conspiracy trying to hide these simple facts of physics
speaks volumes about the sad state of amateur radio.

http://www.mellesgriot.com/products/optics/oc_2_1.htm

It constantly amazes me that the majority of you guys on this thread just can't
seem to get (understand) the truth that Cecil's been trying to get through to
you. Where does the power in the cancelled reflected waves go? Conservation of
energy dictates that it is totally re-reflected when a complete impedance match
has been achieved. You want the wave mechanism that accomplishes this feat? I'll
get to that shortly.

In Steve Best's latest QEX article, Part 3, bottom of Page 43, beginning with
the section titled, "The Total Reflection Fallacy" and continuing ONLY on the
left column of Page 44, Steve tells it like it is, correctly. Then why does he
call it a Fallacy? Please be patient and I'll tell you why.

Steve' correct explanation of the matching process in that single column was
taken directly from my writings in ARRL journals. Paraphrased, yes, but
correctly so.

My first publication of this issue appeared in QST, October 1973, entitled, "A
View Into the Conjugate Mirror." This article appears in both Eds 1 and 2 of
Reflections as Chapter 4, Steve also copied from another of my articles, this
one in QEX,, Mar/Apr 1998, entitled "Examining the Mechanics of Wave
Interference in Impedance Matching," which also appears in Reflections 2 as
Chapter 23.

Steve and I have been in contentious controversy on this subject for several
years. He continued this controversy by publishing this totally erroneous
material in QEX,, erroneous except for the portion in the single column where he
presented my material correctly. The remaining portion of his article is simply
an unsuccessful attempt to show that my position is incorrect, and therefore
calls it a 'fallacy'.

In fact, however, the entire portion following the correct portion he copied
from me is where the REAL fallacy lies--it proves that he knows very little
about the subject of his title, "Wave Mechanics of Transmission Lnes." It also
shows he doesn't have a clue concerning the superposition of two rearward
traveling waves that are conjugately related at the matching point. In fact,
the two waves cancel each other, and establish either a one-way open circuit or
a one-way short circuit that totally re-reflects the reflected power, with its
voltage and current components traveling in the same phase as t;hose from the
source, and therefore adding to the source power.

I know that many on this thread believe that no open or short circuit can be
established by the superposition of waves. It is true that forward and reflected
waves, traveling in OPPOSITE directions establish only the standing wave--no
open or short circuits. But it's a different ball game when two waves traveling
in the SAME direction are conjugately related. The waves are conjugately related
because the canceling wave generated by the matching device is tailored to have
the same magnitude but opposite phase as the wave reflected from the mismatched
load on the transmission line.

Here's why a short or open circuit is established when conjugately related waves
join at a matching point. From an analytic viewpoint the voltage appearing at
any point on the line can be replaced with a generator delivering the same
voltage at the same phase that appears at that point. This generator is called a
'point' generator that delivers an impedance-less EMF. Now consider one
generator delivering the voltage appearing in the wave reflected at the
mismatched load and a second generator delivering the voltage from the canceling
wave reflected by a matching stub, or whatever the matching device, at the same
point on the line as the first. The voltage from this second generator has the
same magnitude, but opposite phase from that of the first generator. When the
voltages delivered by the t wo generators are 180 degrees out of phase we have a
short circuit--if they're in phase we have an open circuit. As the result, in
either of these two conditions no reflected wave can pass rearward of the
matching point.

From the simple fact that the impedance at the input of an antenna tuner is 50+
j0 we know that no reflected power is traveling rearward further than the tuner
input. Where did the power in the reflected wave go? That energy cannot
disappear as if by some sort of magic--it is totally re-reflected by the open or
short circuit, and adds to the source power to establish a forward power equal
to the sum of the source and reflected power.

I hope this helps to end the confusion, and also gives Cecil what he deserves
for his attempt to give you guys the straight dope.

Walt, W2DU