Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old May 25th 10, 07:35 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 2,951
Default Question about "Another look at reflections" article.

On Mon, 24 May 2010 17:17:41 -0700 (PDT), lu6etj
wrote:

PSE, with the due respect and consideration toward you an the
distinguished colleagues and friends, Would you mind return to the
original question? (sorry if it is not this the most polite form to
ask it)


Hi Miguel,

I presume by "original question" you mean:
On Mon, 24 May 2010 13:06:19 -0700 (PDT), lu6etj wrote:

żAbsorb the reflected power or amortiguate the effects of variyng load
impedance?


The answer is YES.

Now, if you mean by absorb that all absorbtion results in heat, then
the answer is NO.

If you mean by absorb that all energy is combined in a load, then the
answer is YES.

The difference between YES and NO is the PHASE differences of the two
energies that are combined.

73's
Richard Clark, KB7QHC
  #2   Report Post  
Old June 1st 10, 06:52 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 143
Default Question about "Another look at reflections" article.

On 25 mayo, 03:35, Richard Clark wrote:
On Mon, 24 May 2010 17:17:41 -0700 (PDT), lu6etj
wrote:

PSE, with the due respect and consideration toward you an the
distinguished colleagues and friends, Would you mind return to the
original question? (sorry if it is not this the most polite form to
ask it)


Hi Miguel,

I presume by "original question" you mean:

On Mon, 24 May 2010 13:06:19 -0700 (PDT), lu6etj wrote:


żAbsorb the reflected power or amortiguate the effects of variyng load
impedance?


The answer is YES.

Now, if you mean by absorb that all absorbtion results in heat, then
the answer is NO.

If you mean by absorb that all energy is combined in a load, then the
answer is YES.

The difference between YES and NO is the PHASE differences of the two
energies that are combined.

73's
Richard Clark, KB7QHC


Hi all

First the first: Sorry Szczepan, do not feel upset I wanted to say
"Me" don't go off topic with my own answers, not you.

Very interesting comments!
I think we must agree on meaning of words and basement concepts
employed to discuss these matters, otherwise we end up talking about
different "things" (Babel curse what confuses our tongues). If we do
not agree with meaning of, for example, "interaction", how can we
reach an agreement on much more complex things that depend on this
word/concept?
This is not a criticism to anyone, is only my point of view about what
I think is a partial source of apparently irreductible positions in
the group.
I believe Richard, K1TTT and me, have sinchronized minds about
"Interaction" word/concept meaning. I suppose must be a more deep
underlying assumptios that make it possible. However I believe I
understand the "idea" underlying Cecil concept about "interaction" and
I believe I can "see" his point, To me, Cecil's interaction concept it
is a very common idea, I do not think Cecil be a "hard to die" man :)
I think we have to do our more honest efforts to sinchronize ideas.
I do not want to go off topic, but let me bring a couple of thinkings
to the table (they are not mine).

* Students come into our classrooms with an established world-view,
formed by years of prior experience and learning.
* Even as it evolves, a student's world-view filters all experiences
and affects their interpretation of observations.
* Students are emotionally attached to their world-views and will not
give up their world-views easily.
* Challenging, revising, and restructuring one's world-view requires
much effort.
(from http://srri.umass.edu/topics/constructivism)

Why these above things would not happen to me?
......
Returning: Cecil, given A+B=C, do you you see C as result of an
interaction (or mutual action) among A and B, or C a simply result of
A added to B?
Another question to clarify my undestanding of your propositions: do
you see waves interacting themselves in a discontinuity, or you see
them interacting with the discontinuity? or both phenomena at the same
time?. Change discontinuity for load and please tell me.

Richard, you said: -"Because" leads to superstition-; you are pointing
to causal relations?
I believe was you who said dislike representations, if it is yes, were
you aiming to create mental images of physical phenomena?
Here we often use the word "methafor" in figured sense instead
"analogy", for example, "my car it is as strong as a locomotive" it is
a true methaphor. In metaphor, there are two levels or terms: the real
(my car) and evoked or imaginary (locomotive). Coulored water is it a
true methaphor or an analogy?

Simple analogies as useful things until one (or more) of they not
work... then, ciao analogy..!, not so bad :), however... notice!, our
ideas are not equal to the "out there" world. Concepts, models,
(mathematical models also, of course)... are not they our mind's
"analogies" "out there" sensorial/injstrumental perceived world?
These are not trivial epistemology issues, our "observer" leads
directly to the question about "Is the moon there when nobody
looks?" (N. D.Mermin). When we go out of our classic-simplistic-
realistic-traditional ham world... "we are in troubles, Houston",
slippery soil!, I make the sign of the cross! :)

K1TTT said: -Standing waves are a figment of your instrumentation-. My
dictionary translates "figment" as "product" or "chimera", please,
tell me what word should I use to correctly read the sentence?

73

Miguel Ghezzi - LU6ETJ

  #3   Report Post  
Old June 1st 10, 09:30 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Oct 2009
Posts: 707
Default Question about "Another look at reflections" article.


"lu6etj" wrote
...

Here we often use the word "methafor" in figured sense instead

"analogy", for example, "my car it is as strong as a locomotive" it is
a true methaphor. In metaphor, there are two levels or terms: the real
(my car) and evoked or imaginary (locomotive). Coulored water is it a
true methaphor or an analogy?

Simple analogies as useful things until one (or more) of they not

work... then, ciao analogy..!,

Radio waves and sound are in full analogy.

K1TTT said: -Standing waves are a figment of your instrumentation-. My

dictionary translates "figment" as "product" or "chimera", please,
tell me what word should I use to correctly read the sentence?

Waves always travel (pressure or voltage pulses). If the wave interact with
the reflected one than the places where the pressures/voltages change are
standing.

The reflected wave cam be weaker if the mirror is partialy transparent (or
if an absorbtion take place).
S*

73

Miguel Ghezzi - LU6ETJ


  #4   Report Post  
Old June 1st 10, 11:50 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Apr 2010
Posts: 484
Default Question about "Another look at reflections" article.

On Jun 1, 5:52*am, lu6etj wrote:
On 25 mayo, 03:35, Richard Clark wrote:



On Mon, 24 May 2010 17:17:41 -0700 (PDT), lu6etj
wrote:


PSE, with the due respect and consideration toward you an the
distinguished colleagues and friends, Would you mind return to the
original question? (sorry if it is not this the most polite form to
ask it)


Hi Miguel,


I presume by "original question" you mean:


On Mon, 24 May 2010 13:06:19 -0700 (PDT), lu6etj wrote:


żAbsorb the reflected power or amortiguate the effects of variyng load
impedance?


The answer is YES.


Now, if you mean by absorb that all absorbtion results in heat, then
the answer is NO.


If you mean by absorb that all energy is combined in a load, then the
answer is YES.


The difference between YES and NO is the PHASE differences of the two
energies that are combined.


73's
Richard Clark, KB7QHC


Hi all

First the first: Sorry Szczepan, do not feel upset *I wanted to say
"Me" don't go off topic with my own answers, not you.

Very interesting comments!
I think we must agree on meaning of words and basement concepts
employed to discuss these matters, otherwise we end up talking about
different "things" (Babel curse what confuses our tongues). If we do
not agree with meaning of, for example, "interaction", how can we
reach an agreement on much more complex things that depend on this
word/concept?
This is not a criticism to anyone, is only my point of view about what
I think is a partial source of apparently irreductible positions in
the group.
I believe Richard, K1TTT and me, have sinchronized minds about
"Interaction" word/concept meaning. I suppose must be a more deep
underlying assumptios that make it possible. However I believe I
understand the "idea" underlying Cecil concept about "interaction" and
I believe I can "see" his point, To me, Cecil's interaction concept it
is a very common idea, I do not think Cecil be a "hard to die" man :)
I think we have to do our more honest efforts to sinchronize ideas.
I do not want to go off topic, but let me bring a couple of thinkings
to the table (they are not mine).

* Students come into our classrooms with an established world-view,
formed by years of prior experience and learning.
* Even as it evolves, a student's world-view filters all experiences
and affects their interpretation of observations.
* Students are emotionally attached to their world-views and will not
give up their world-views easily.
* Challenging, revising, and restructuring one's world-view requires
much effort.
(fromhttp://srri.umass.edu/topics/constructivism)

Why these above things would not happen to me?
.....
Returning: Cecil, given A+B=C, do you you see C as result of an
interaction (or mutual action) among A and B, or C a simply result of
A added to B?
Another question to clarify my undestanding of your propositions: do
you see waves interacting themselves in a discontinuity, or you see
them interacting with the discontinuity? or both phenomena at the same
time?. Change discontinuity for load and please tell me.

Richard, you said: -"Because" leads to superstition-; you are pointing
to causal relations?
I believe was you who said dislike representations, if it is yes, were
you aiming to create mental images of physical phenomena?
Here we often use the word "methafor" in figured sense instead
"analogy", for example, "my car it is as strong as a locomotive" it is
a true methaphor. In metaphor, there are two levels or terms: the real
(my car) and evoked or imaginary (locomotive). Coulored water is it a
true methaphor or an analogy?

Simple analogies as useful things until one (or more) of they not
work... then, ciao analogy..!, not so bad :), however... notice!, our
ideas are not equal to the "out there" world. Concepts, models,
(mathematical models also, of course)... are not they our mind's
"analogies" "out there" sensorial/injstrumental perceived world?
These are not trivial epistemology issues, our "observer" leads
directly to the question about "Is the moon there when nobody
looks?" (N. D.Mermin). When we go out of our classic-simplistic-
realistic-traditional ham world... "we are in troubles, Houston",
slippery soil!, I make the sign of the cross! :)

K1TTT said: -Standing waves are a figment of your instrumentation-. My
dictionary translates "figment" as "product" or "chimera", please,
tell me what word should I use to correctly read the sentence?

73

Miguel Ghezzi - LU6ETJ


in this context figment=product. often used to describe something
that is a result of an over active imagination. the only reason you
can see standing waves is because a measurement or observation makes
them look like they are 'standing' when it is really the interaction
of two or more regular traveling waves.
  #5   Report Post  
Old June 1st 10, 12:23 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Aug 2006
Posts: 572
Default Question about "Another look at reflections" article.

On Jun 1, 12:52*am, lu6etj wrote:
Returning: Cecil, given A+B=C, do you you see C as result of an
interaction (or mutual action) among A and B, or C a simply result of
A added to B?


Of course, there are all types of "addition", e.g. arithmetic,
algebraic, voltage phasor, Poynting vector, scalar power,
superposition, merging, mixing, ... Which type of "addition" is
appropriate depends upon the nature of what is being added.

Simply put, if A + B = C creates an irreversible result, then A has
(obviously?) interacted with B. If the result is reversible, then A
has not interacted with B. For the great majority of cases,
superposition does not result in interaction. For the great majority
of cases, interference does not result in interaction. For some
(special?) cases, superposition (plus associated interference and wave
cancellation) results in interaction and the result is irreversible.
Non reflective glass is an example of wave interaction. The internal
reflection cancels the external reflection and the energy in those two
reflections changes directions. A Z0-match at an impedance
discontinuity in an RF transmission line is another example. Again, if
two waves are coherent, collimated, and traveling in the same
direction, those two waves will interact, i.e. their superposition
result is not reversible.
--
73, Cecil, w5dxp.com


  #6   Report Post  
Old June 1st 10, 02:10 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Apr 2010
Posts: 484
Default Question about "Another look at reflections" article.

On Jun 1, 11:23*am, Cecil Moore wrote:
On Jun 1, 12:52*am, lu6etj wrote:

Returning: Cecil, given A+B=C, do you you see C as result of an
interaction (or mutual action) among A and B, or C a simply result of
A added to B?


Of course, there are all types of "addition", e.g. arithmetic,
algebraic, voltage phasor, Poynting vector, scalar power,
superposition, merging, mixing, ... Which type of "addition" is
appropriate depends upon the nature of what is being added.

Simply put, if A + B = C creates an irreversible result, then A has
(obviously?) interacted with B. If the result is reversible, then A
has not interacted with B. For the great majority of cases,
superposition does not result in interaction. For the great majority
of cases, interference does not result in interaction. For some
(special?) cases, superposition (plus associated interference and wave
cancellation) results in interaction and the result is irreversible.
Non reflective glass is an example of wave interaction. The internal
reflection cancels the external reflection and the energy in those two
reflections changes directions. A Z0-match at an impedance
discontinuity in an RF transmission line is another example. Again, if
two waves are coherent, collimated, and traveling in the same
direction, those two waves will interact, i.e. their superposition
result is not reversible.
--
73, Cecil, w5dxp.com


what exactly is the 'interaction' and why is it unique to that
special coherent, collimated, etc, case? if two waves can 'interact'
in that case there should be other evidence that they can interact in
other situations. just because a+b=c doesn't mean that a and b have
magically disappeared for some reason, in mathematics c=a+b is just as
valid and implies that c is made up of a and b... or using your water
analogy, adding one pint to another pint doesn't magically cause them
to 'interact' in some way, the original water is still there, perhaps
indistinguishable from each other, but still there. it may be
convenient to represent the result of summing an infinite series of
reflections as a single number, but it is not necessary.
  #7   Report Post  
Old June 1st 10, 02:52 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Aug 2006
Posts: 572
Default Question about "Another look at reflections" article.

On Jun 1, 8:10*am, K1TTT wrote:
what exactly is the 'interaction' *and why is it unique to that
special coherent, collimated, etc, case?


Is it not obvious that when two reflected waves cancel in one
direction, as at the surface of a 1/4WL thin-film coating on glass,
and their combined EM energy is redistributed in the opposite
direction, that those two waves have interacted, i.e. have suffered a
permanent change and have lost their original identities?

Is it not obvious that when two waves are traveling two different
paths where the incident angle is, e.g. two degrees, that those two
waves will superpose and interfere throughout a certain space after
which they emerge intact, unaffected, and have obviously not
interacted, i.e. they suffered no permanent change and have maintained
their original identities?

Did superposition occur in both cases? Yes. Did interference occur in
both cases? Yes. Did wave cancellation occur in both cases? No, just
in the non-reflective glass case.

Consider a transmission line with an SWR of 5.83:1. The sourced power
is 100 watts. The forward power is 200 watts. The reflected power is
100 watts. All of the reflected power is redistributed back toward the
load at a Z0-match through reflection and wave cancellation. Zero
reflected power is incident upon the source.

Does the 100w source wave lose its identity when it merges with the
100w of redistributed reflected wave to become the 200w forward wave?
Is the steady-state load energy coming from the source wave or the
redistributed reflected wave or both? Seems to me, it is obvious that
the two original component waves have interacted and lost their
original identities for good if they are pure coherent sine waves
traveling in the same direction confined to a coaxial transmission
line.
--
73, Cecil, w5dxp.com
  #8   Report Post  
Old June 1st 10, 11:44 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Apr 2010
Posts: 484
Default Question about "Another look at reflections" article.

On Jun 1, 1:52*pm, Cecil Moore wrote:
On Jun 1, 8:10*am, K1TTT wrote:

what exactly is the 'interaction' *and why is it unique to that
special coherent, collimated, etc, case?


Is it not obvious that when two reflected waves cancel in one
direction, as at the surface of a 1/4WL thin-film coating on glass,
and their combined EM energy is redistributed in the opposite
direction, that those two waves have interacted, i.e. have suffered a
permanent change and have lost their original identities?

Is it not obvious that when two waves are traveling two different
paths where the incident angle is, e.g. two degrees, that those two
waves will superpose and interfere throughout a certain space after
which they emerge intact, unaffected, and have obviously not
interacted, i.e. they suffered no permanent change and have maintained
their original identities?


no, it is not obvious. where do you draw the line... 1 degree, .1
degree, .001 degree? at what point is the angle small enough to say
that they have 'interacted' and the energy is redistributed?


Did superposition occur in both cases? Yes. Did interference occur in
both cases? Yes. Did wave cancellation occur in both cases? No, just
in the non-reflective glass case.


i propose that 'cancellation' is just a special case of interference
where the waves are 'close enough' to collinear that you never see the
interference pattern. this would of course always apply in a
transmission line because they are confined.

closely analyze the transient response of your non-reflective glass in
the case where the wave is not incident perpendicular to the glass.
do each reflection from each interface separately as the wave travels
in the coating at an angle. then reduce the angle to very near
perpendicular and you should see that there are indeed reflections
that should very nearly 'cancel' each other out as the number of
reflections gets bigger.
  #9   Report Post  
Old June 2nd 10, 04:31 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Aug 2006
Posts: 572
Default Question about "Another look at reflections" article.

On Jun 1, 5:44*pm, K1TTT wrote:
no, it is not obvious. *where do you draw the line... 1 degree, .1
degree, .001 degree? *at what point is the angle small enough to say
that they have 'interacted' and the energy is redistributed?


I don't know the answer but zero degrees (perfect collimation) will
result in interaction.

i propose that 'cancellation' is just a special case of interference
where the waves are 'close enough' to collinear that you never see the
interference pattern.


When b1 = s11*a1 + s12*a2 = 0 at an impedance discontinuity, wave
cancellation has taken place. s11*a1 and s12*a2 are coherent sine
waves, equal in magnitude, and 180 degrees out of phase. Have you read
the FSU web page where they describe wave cancellation? All these
concepts are old hat to optical physicists.

micro.magnet.fsu.edu/primer/java/scienceopticsu/interference/
waveinteractions/index.html

"... when two waves of equal amplitude and wavelength that are 180-
degrees ... out of phase with each other meet, they are not actually
annihilated, ... All of the photon energy present in these waves must
somehow be recovered or redistributed in a new direction, according to
the law of energy conservation ... Instead, upon meeting, the photons
are redistributed to regions that permit constructive interference, so
the effect should be considered as a redistribution of light waves and
photon energy rather than the spontaneous construction or destruction
of light."
--
73, Cecil, w5dxp.com
  #10   Report Post  
Old June 1st 10, 06:27 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 2,951
Default Question about "Another look at reflections" article.

On Mon, 31 May 2010 22:52:35 -0700 (PDT), lu6etj
wrote:

Richard, you said: -"Because" leads to superstition-; you are pointing
to causal relations?


Hi Miguel,

Language would have us believe that causal relations "be" from
"cause." Common language sometimes uses "because" as a bridge between
phrases without necessarily implying causality - in other words, the
word "because" is verbal noise when that happens. "Because" is often
a one word reply to a child's question "Why?"

I believe was you who said dislike representations, if it is yes, were
you aiming to create mental images of physical phenomena?


Oh, I do that all the time. However, I do not mistake representations
as being the real thing. In other contexts, they are more real than
the real thing. So, if there is dislike, it comes from seeing
inferior representation when better work requires so little more
effort.

Here we often use the word "methafor"

now there's a curious and suggestive spelling
in figured sense instead
"analogy", for example, "my car it is as strong as a locomotive" it is
a true methaphor. In metaphor, there are two levels or terms: the real
(my car) and evoked or imaginary (locomotive). Coulored water is it a
true methaphor or an analogy?


Both. But context should resolve that, or it could still be both.
That is why metaphor and analogy are so dangerous. That is also why
it is so useful in fiction. We get enough fiction here.

Simple analogies as useful things until one (or more) of they not
work... then, ciao analogy..!, not so bad :), however... notice!, our
ideas are not equal to the "out there" world. Concepts, models,
(mathematical models also, of course)... are not they our mind's
"analogies" "out there" sensorial/injstrumental perceived world?
These are not trivial epistemology issues, our "observer" leads
directly to the question about "Is the moon there when nobody
looks?" (N. D.Mermin). When we go out of our classic-simplistic-
realistic-traditional ham world... "we are in troubles, Houston",
slippery soil!, I make the sign of the cross! :)


Namaste.

73's
Richard Clark, KB7QHC


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Chapter 19A from "Reflections III" - Step 9 response Richard Clark Antenna 0 June 21st 08 10:50 PM
Chapter 19A from "Reflections III" - Step 8 response Richard Clark Antenna 0 June 21st 08 10:50 PM
Chapter 19A from "Reflections III" - Step 7 response Richard Clark Antenna 0 June 21st 08 10:48 PM
Chapter 19A from "Reflections III" - Step Reviews Overview Richard Clark Antenna 0 June 21st 08 10:45 PM
Use "Tape Out" Or "Ext Speaker" Output For PC's Line-In ? And, acars question Robert11 Scanner 7 June 15th 06 01:54 PM


All times are GMT +1. The time now is 05:10 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017