Richard Clark wrote:
You want to be last? Hug Tom and pull the pin!

"He who laughs last, laughs best." Stand by.
--
73, Cecil http://www.w5dxp.com

On Sun, 09 Dec 2007 15:11:49 -0800, John Smith
wrote:

The majority of your text has turned to attacking personalities

Personal advice from the anonymous. More irony than value there; and
you could as easily be Ossama Bin Forgotten wishing us Deadly
Christmas and a Satan hugging New Year muttered under your beard.

Others might teach me about manners, but they haven't weighed in, have
they? They would put the substance of their names behind their
lesson, and they would have a reputation of civil discourse in
contrast to mine. It's happened before, but you and Cecil aren't
standing in that long line.

Not only is this boring, it is plain disgusting. My gawd man, step back
for a moment or two and get a hold of yourself.

As for being bored? This has been a grind, certainly; 600+ postings
informs us all of that! [Talk about the bleeding obvious. Reggie
would have his thumb in your eye.] You getting bored, however, speaks
only to your own veiled hedonism. Your moral balance is seized with
the rust of anonymity.

Want to move away from personalities? Try participating with
technical comments or providing data. Cecil abandoned it with his
claim of being hounded with 20 questions. How many more than 20
questions litter this thread from him? How much data arrived from
those 20 questions? Did you find yourself informed during that
interchange? Did none of them raise your interest to engage your own
participation? Was there anything in their relation to the
measurement that revealed success or failure? Did you find anything
"personal" in their revelation? Did you laud or challenge that
enquiry or its analysis? Did it elicit any questions? Frankly, you
show very little interest in these topics except when the
entertainment becomes a bit too purple. It has, no doubt about it;
but you don't even have the critic's qualifications to do anything
more than phone in a vote to American Idol and hope Simon doesn't pick
up the line.

You chose to respond to the comedy, and stood silent in the exchange
of idea and information. No, I don't see any lesson offered here by
you that you don't need learning first.

73's
Richard Clark, KB7QHC

Cecil Moore wrote:
Tom Donaly wrote:
I think it's about time to boycott Cecil

Which means that you have run my suggested experiments
and realize that I am right so you are going to ploink
me like others have done in the past. Somehow, I
expected more out of you, Tom, than simply the guru
party line.

If I am wrong, it should be easy to prove. If I am
right, I deserve to be boycotted???? Shades of Galileo.

I don't have time to run your suggested experiments, Cecil.
I'm sure that even you will be able to do them, yourself, given the will.
73,
Tom Donaly, KA6RUH

Roy Lewallen wrote:
A standing wave is the result of isn't the sum
of traveling waves. It's a description of the envelope of the current
distribution that sum produces.

At least three years ago, I told W7EL that the equation
for standing wave current is K*cos(kx)*cos(wt) so he
is well aware that his above assertion is false. I
have no idea why he chooses to promote some personal
agenda instead of technical facts.
--
73, Cecil http://www.w5dxp.com

Tom Donaly wrote:
I don't have time to run your suggested experiments, Cecil.

I suspect that you have run those experiments and know
that I am right so you can't afford to post the results.
Many gurus have sacrificed their integrity in like manner.

If I am so wrong, someone should have been able to prove
it by now based on bench experiments. The lack of proof
that I am wrong speaks volumes.

What I don't understand is the agenda to promote false
technical concepts. Could you explain that to us?
--
73, Cecil http://www.w5dxp.com

Richard Clark wrote:
...
Personal advice from the anonymous. More irony than value there; and
you could as easily be Ossama Bin Forgotten wishing us Deadly
Christmas and a Satan hugging New Year muttered under your beard.


As Cecil, so eloquently, pointed out--others will know you by your
posts, they'll figure me out too ...

Others might teach me about manners, but they haven't weighed in, have
they? They would put the substance of their names behind their
lesson, and they would have a reputation of civil discourse in
contrast to mine. It's happened before, but you and Cecil aren't
standing in that long line.


Yes, shallow "Hero Worship" is at the core of your being ... we already
knew that, you kiss the gods butt, they kiss yours--sometimes ...


As for being bored? This has been a grind, certainly; 600+ postings
informs us all of that! [Talk about the bleeding obvious. Reggie
would have his thumb in your eye.] You getting bored, however, speaks
only to your own veiled hedonism. Your moral balance is seized with
the rust of anonymity.


I pity newbie hams, they have to figure out that your kind can be easily
avoided and the hobby can still be enjoyable, too bad we lose a few that
can't stomach the BS ...

Want to move away from personalities? Try participating with
technical comments or providing data. Cecil abandoned it with his
claim of being hounded with 20 questions. How many more than 20
questions litter this thread from him? How much data arrived from
those 20 questions? Did you find yourself informed during that
interchange? Did none of them raise your interest to engage your own
participation? Was there anything in their relation to the
measurement that revealed success or failure? Did you find anything
"personal" in their revelation? Did you laud or challenge that
enquiry or its analysis? Did it elicit any questions? Frankly, you
show very little interest in these topics except when the
entertainment becomes a bit too purple. It has, no doubt about it;
but you don't even have the critic's qualifications to do anything
more than phone in a vote to American Idol and hope Simon doesn't pick
up the line.


Frankly, and certainly, at this point, I do not feel accustomed enough
to a smith chart, the "nuiances" of reflected waves nor the esoteric
concepts which are being argued--I am attempting to come up to speed.
Nothing wrong with being a student and that is what I am in this
debate/exchange/discourse/argument/etc.

You chose to respond to the comedy, and stood silent in the exchange
of idea and information. No, I don't see any lesson offered here by
you that you don't need learning first.


Richard, if you could not have made it as a test tech, you could have
always joined the circus as a clown, I am sure you would have been quite
successful! I only wonder how clowns of the Shakespearian era dressed? ;-)

73's
Richard Clark, KB7QHC

3's right back at 'ya--good buddy,
and regards,
JS

Roy Lewallen wrote:
Roger wrote:
Hi Roy,

Could I add this observation? Both traveling waves and standing
waves can be measured. A single volt meter or ammeter will measure
the standing wave which is the sum of the traveling waves..

This isn't quite correct. A standing wave is the result of isn't the
sum of traveling waves. It's a description of the envelope of the
current distribution that sum produces. The sum of the traveling wave
voltages is the total voltage. The sum of the traveling wave currents
is the total current. It's relatively to measure the total voltage or
current at any point and, if you measure them at enough points you can
use the measurements to draw a graph of the standing wave.
Yes, you have said it better than I.

A DIRECTIONAL volt meter or ammeter will measure only the traveling
wave within the design direction, but can not distinguish between
components from multiple reflections that might combine.

Yes.

A directional voltmeter or ammeter will measure the same voltage or
current no matter where it is placed in the transmission line under
steady state conditions, assuming no resistive losses in the
transmission line.

That's only partially true. Both the traveling waves and the total
voltage and current have not only magnitude but also phase. A
directional coupler can measure both the magnitude and phase of the
traveling waves (but some directional detectors like a Bird wattmeter
indirectly measure only the amplitude). Traveling wave measurements at
different points along a lossless line will have the same magnitude,
but different phases. So the voltages or currents at those points
aren't the same.

Roy Lewallen, W7EL
This last paragraph gets to the heart of the issue. One concept of a
transmission line is that the traveling wave is always in phase in the
sense that the power contained in the wave is the envelope that is
properly considered. In this concept, the voltage and current are
always in phase, MUST be in phase. This power wave may be split as at a
reflection point, but the components will never be out of phase because
the power calculation would be incorrect.if it was out of phase.

The second concept of a transmission line allows the traveling wave to
have voltage out of phase with the current. Here the power can be all
stored in either the current (magnetic) field or the voltage field,
depending upon the phase of the traveling wave. The character of the
wave changes (so to speak) depending upon location and phase.

If the transmission line is terminated with a resistance, the
constantly-in-phase traveling wave concept provides the theoretical
basis for calculation of the reflection coefficient.

I think that consideration of the conditions at the end of a
transmission line are a good place to examine as we try to get some
experimental guidance.

If the transmission line is shorted (or open), it is hard to visualize
how the voltage (or current) could flow to the short (or open) and then
just disappear. Does the wave cancel (or disappear) at the
intersection (open end)? Do the waves pass through each other, so we
see only the vector sum? Do the waves "pile up" at the open end, but
not at the short?

The constantly-in-phase traveling wave concept requires the
difficult-to-believe observation that a directional ammeter placed very
near the end of an open transmission line will read the same current as
if it were placed at the source end. Perhaps someone can perform that
experiment some day, but I can not imagine how it can be done without
placing a load on the line, thus invalidating the initial assumptions.

73, Roger, W7WKB

Roger wrote:
Roy Lewallen wrote:

That's only partially true. Both the traveling waves and the total
voltage and current have not only magnitude but also phase. A
directional coupler can measure both the magnitude and phase of the
traveling waves (but some directional detectors like a Bird wattmeter
indirectly measure only the amplitude). Traveling wave measurements at
different points along a lossless line will have the same magnitude,
but different phases. So the voltages or currents at those points
aren't the same.

Roy Lewallen, W7EL
This last paragraph gets to the heart of the issue. One concept of a
transmission line is that the traveling wave is always in phase in the
sense that the power contained in the wave is the envelope that is
properly considered. In this concept, the voltage and current are
always in phase, MUST be in phase. This power wave may be split as at a
reflection point, but the components will never be out of phase because
the power calculation would be incorrect.if it was out of phase.

Sorry, I can't make much sense out of that. Voltage and current don't
have to be in phase in order for power (energy flow) to be present. But
I'd rather not introduce power into the discussion. It's not necessary
in explaining what I've presented, and brings the opportunity for a
whole new level of misunderstanding and folklore.

The second concept of a transmission line allows the traveling wave to
have voltage out of phase with the current. Here the power can be all
stored in either the current (magnetic) field or the voltage field,
depending upon the phase of the traveling wave. The character of the
wave changes (so to speak) depending upon location and phase.

The ratio of V to I of the traveling wave is the Z0 of the line. In a
lossless line, this is a pure resistance, so the V and I of traveling
waves are in phase.

If the transmission line is terminated with a resistance, the
constantly-in-phase traveling wave concept provides the theoretical
basis for calculation of the reflection coefficient.

The reflection coefficient can easily be calculated regardless of
whether or not the load impedance is resistive or reactive. The load
impedance doesn't have any effect on the relationship between V and I
traveling waves going the same direction; it affects only the amplitude
and phase relationship between waves going in opposite directions.

I think that consideration of the conditions at the end of a
transmission line are a good place to examine as we try to get some
experimental guidance.
If the transmission line is shorted (or open), it is hard to visualize
how the voltage (or current) could flow to the short (or open) and then
just disappear. Does the wave cancel (or disappear) at the
intersection (open end)? Do the waves pass through each other, so we
see only the vector sum? Do the waves "pile up" at the open end, but
not at the short?

The voltage and current at any point along a line, including the ends,
equals the sum of the forward and reflected voltage or current waves at
that point. At a short circuit, the voltage is zero. This means that the
sum of the forward and reverse waves at that point is zero, which in
turn means that the two are equal in magnitude and out of phase.
(Another way of saying this is that the voltage reflection coefficient
is -1 at that point.) At an open circuit, the current is zero. I'll
leave it as an exercise to the reader to figure out what this means
about the relationship between the forward and reverse traveling current
waves.

The constantly-in-phase traveling wave concept requires the
difficult-to-believe observation that a directional ammeter placed very
near the end of an open transmission line will read the same current as
if it were placed at the source end. Perhaps someone can perform that
experiment some day, but I can not imagine how it can be done without
placing a load on the line, thus invalidating the initial assumptions.

73, Roger, W7WKB

Sounds like a good experiment for you to do. Please post your results
here so others can learn from them.

Roy Lewallen, W7EL

Correction:

Roy Lewallen wrote:

This isn't quite correct. A standing wave is the result of isn't the sum
of traveling waves. It's a description of the envelope of the current
distribution that sum produces. . .

It should read:

This isn't quite correct. A standing wave isn't the sum of traveling
waves. It's a description of the envelope of the current distribution
that sum produces. . .

Roy Lewallen, W7EL

On Dec 9, 9:36 pm, Roger wrote:
The constantly-in-phase traveling wave concept requires the
difficult-to-believe observation that a directional ammeter placed very
near the end of an open transmission line will read the same current as
if it were placed at the source end. Perhaps someone can perform that
experiment some day, but I can not imagine how it can be done without
placing a load on the line, thus invalidating the initial assumptions.

The experiment will show the expected result but will
not help understand why. For that, examination of
the measurements and arithmetic performed by
a directional ammeter is useful.

Below, all voltages and currents are instantaneous.

Total voltage, Vt = Vf + Vr
Total current, It = If - Ir

Vf = If * Z0
Vr = Ir * Z0

Substituting....

Vt = (If + Ir) * Z0
Ir = Vt/Z0 - If

If = It + Ir
If = It + (Vt/Z0 - If)
If = (It + Vt/Z0)/2

Similarly, Ir = (It - Vt/Z0)/2

The directional ammeter measures instantaneous
Vt and It, does the above arithmetic and presents
If. A directional ammeter that presents a single
number rather than the time varying If has probably
converted the instantaneous values to RMS.

Examing It and Vt at various points on the line
and doing the above arithmetic will reveal why
the same value for If is obtained everywhere.

Directional wattmeters are more common
than directional ammeters. A directional
wattmeter does the above arithmetic then
squares If, multiplies by Z0 and presents
the results in watts.

All this from just measuring Vt and It.

....Keith