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  #271   Report Post  
Old April 9th 06, 07:13 PM posted to rec.radio.amateur.antenna
Cecil Moore
 
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Default Current across the antenna loading coil - from scratch

John Popelish wrote:
If we assume the coil is an idealized lumped inductance with no stray
capacitance at all (not a real inductor) then it would have the same
instantaneous current at each end and that current would be zero, since
it has zero size. In other words it would fit entirely in the point
that holds the node.


And such a coil is impossible in the real world so why even mention it?
I want to hear about real world one foot long, 100 uH coils.

Real inductors with stray capacitance and imperfect magnetic coupling
for all parts of its internal current path, would have a phase shift in
the current at opposite ends, so they would have current at their ends
that was 180 degrees out of phase, if they were centered on the node
points.


Yes, now please tell that to W8JI and W7EL. They are not listening
to me.

I am not arguing for the validity of that measurement. Argue about it
with someone who is.


That's my entire argument at the moment and W7EL is avoiding that
argument like a plague.

In case you don't realize, there is more than one person out here,
responding to you.


Please forgive me for not recognizing which of the ten individual
junk yard dog "experts" is biting my ankles at any particular time. :-)

You remind me of a type of insanity where the sufferer thinks that
everything he is experiencing an organized illusion by a single
offending intelligence (you against the Matrix) bent on forcing him to
think that a lie is the truth, regardless of who or what he deals with.
Everyone he meets, every apparently random happenstance, the actions of
his dog and the weather, generally, are all a conspiracy to force him to
think that black is white, and he isn't going to fall for it.


IMHO, hardly anyone here on r.r.a.a is interested in technical facts.
Most "experts" think they already know everything, wouldn't recognize
a differing concept if it bit them in the arse, and are more dedicated
to preserving the pecking order than anything else. 'Course, I am only
human and could, therefore, unlike the omniscient experts, be wrong
about that.
--
73, Cecil http://www.qsl.net/w5dxp
  #272   Report Post  
Old April 9th 06, 07:34 PM posted to rec.radio.amateur.antenna
Cecil Moore
 
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Default Current across the antenna loading coil - from scratch

John Popelish wrote:
I am making the point that if the displacement currents were
insignificant, outside a coax, then the speed of light for waves out
there would be infinite. And they are not, therefore those displacement
currents cannot be assumed to be insignificant.


But I am not talking about displacement currents within the
transmission line, as exists in free space. I am talking *solely*
about the displacement currents to *earth ground*. I contend that
those are often secondary effects as proven by the coax example.
Just how much displacement current to "earth ground" is there for
a coil located halfway between here and Alpha Centauri?

Exactly the opposite. I am explaining the distributed effect of the E
field along the wave.


And completely ignoring the H-field? In the treatment of those fields,
the only variation is Z0. For EM fields, there is no "across" and no
"through". The difference between voltage and current essentially
disappears except for their Z0 ratio. The equation for current in
a transmission line is identical to the equation for voltage except
for the Z0 term. Current "drops" are commonplace in lossy transmission
lines.

For instance, what is the current at the end of 200 feet of RG-58
terminated by a 50 ohm antenna used on 446 MHz when the source
current is 2 amps?

You are avoiding the very facts that would allow you to make an air
tight argument for your beliefs about "the whole point of the
discussion". You somehow picture current as a continuous thing from one
end of a conductor to the other, when it carries a traveling energy
wave. This is a misconception.


Maybe in the field of physics - not in the field of RF engineering.
For any two current points, I can calculate a point in between.
Sorry, but that's a characteristic of a *continuous* single-valued
function and can be proven mathematically. I admit to being a EE/math
major. I didn't take many pure physics courses so I am missing your
point about me being able to prove anything additional. Maybe it
will dawn on me after awhile.

What you don't get is, that the currents that each of those traveling
waves would have generated were localized, to begin with.


I realize that is the physicist talking and it agrees with my
earlier assertion that standing wave current doesn't flow. I
guess I'm so dense that I need help in proving what you think
I can prove with that information. Right now, I am apparently
missing something, maybe because of too much California Merlot.
--
73, Cecil http://www.qsl.net/w5dxp
  #273   Report Post  
Old April 9th 06, 07:52 PM posted to rec.radio.amateur.antenna
Cecil Moore
 
Posts: n/a
Default Current across the antenna loading coil - from scratch

John Popelish wrote:
The definition of "local" is wavelength dependent.


Since the reality in which we exist has been proven to be
non-local in nature, I'm wondering what is your point?

Back to the RF case: Do you imagine that electrons from the source
reach the load?


Maybe for DC. But depending upon the length of the transmission
line, probably not for HF RF. Is that a rhetorical question?

Someone needs to tell that to W7EL. I've tried to tell him but
instead of thanking me, he 'ploinked' me.


Perhaps he has lost interest in this thread.
Perhaps he is taking this topic personally.
Perhaps he enjoys yanking your chain.
Perhaps ...


.... he is afraid of losing his "expert" status?

What does any of that have to do with our conversation?


Everything. That's what this thread is all about. I will repeat:

Can the standing wave current phase, with its unchanging phase,
be used to measure the phase shift through a wire or coil?

That's the admittedly narrow present topic. The answer is either
'yes' or 'no'. After we answer that narrow technical question,
the discussion can procede.
--
73, Cecil http://www.qsl.net/w5dxp
  #274   Report Post  
Old April 9th 06, 07:57 PM posted to rec.radio.amateur.antenna
Cecil Moore
 
Posts: n/a
Default Current across the antenna loading coil - from scratch

Richard Clark wrote:
Lot of bafflegab in that. I will take it to mean yes.


Whatever way you choose to "take it" has absolutely no
effect on any reality except your own personal reality
existing only in your head. Enjoy!
--
73, Cecil http://www.qsl.net/w5dxp
  #275   Report Post  
Old April 9th 06, 08:01 PM posted to rec.radio.amateur.antenna
John Popelish
 
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Default Current across the antenna loading coil - from scratch

Cecil Moore wrote:
John Popelish wrote:

If we assume the coil is an idealized lumped inductance with no stray
capacitance at all (not a real inductor) then it would have the same
instantaneous current at each end and that current would be zero,
since it has zero size. In other words it would fit entirely in the
point that holds the node.



And such a coil is impossible in the real world so why even mention it?


Because it is the limiting case of the possible. Understanding why it
is the limit interests me.

I want to hear about real world one foot long, 100 uH coils.


Then you have changed your mind from a few days ago.
No problem for me.

Real inductors with stray capacitance and imperfect magnetic coupling
for all parts of its internal current path, would have a phase shift
in the current at opposite ends, so they would have current at their
ends that was 180 degrees out of phase, if they were centered on the
node points.



Yes, now please tell that to W8JI and W7EL. They are not listening
to me.


I just did. I hope you realize that anyone is perfectly free to
ignore anything posted to this or any other newsgroup, and long as it
pleases them. If you are going to have trouble sleeping because you
can't get complete agreement from everyone who you have ever seen post
to this group, your problems are a lot bigger than coils and waves.

I am not arguing for the validity of that measurement. Argue about it
with someone who is.


That's my entire argument at the moment and W7EL is avoiding that
argument like a plague.


That is their prerogative. Deal with it. I am putting considerable
effort to understand the physics of the situation and to share my
thoughts with you. If this is no interest to you, I will discuss this
interesting topic with someone else.

In case you don't realize, there is more than one person out here,
responding to you.


Please forgive me for not recognizing which of the ten individual
junk yard dog "experts" is biting my ankles at any particular time. :-)


I am insulted that you include me in that derogatory characterization.
I have been polite, patient and respectful with you in this
discussion.

You remind me of a type of insanity where the sufferer thinks that
everything he is experiencing an organized illusion by a single
offending intelligence (you against the Matrix) bent on forcing him to
think that a lie is the truth, regardless of who or what he deals
with. Everyone he meets, every apparently random happenstance, the
actions of his dog and the weather, generally, are all a conspiracy to
force him to think that black is white, and he isn't going to fall for
it.


IMHO, hardly anyone here on r.r.a.a is interested in technical facts.
Most "experts" think they already know everything, wouldn't recognize
a differing concept if it bit them in the arse, and are more dedicated
to preserving the pecking order than anything else. 'Course, I am only
human and could, therefore, unlike the omniscient experts, be wrong
about that.


And that is exactly why I have refrained from personal attacks (though
I have indulged in a few observations as above, because I think
considering them might open your eyes to how you appear to others, and
how that interferes with your arguments. So even those observations
were not made in an attempt to win an argument with you, but to assist
you in thinking more clearly.

For the most part, I have tried to talk about physics, not pecking
order or personalities. But you keep cutting me off, saying you are
not interested in physics, but in winning a debate with a few people,
regardless of who you have to insult to win.

At this point, my mental model of how your mind works is just about as
interesting to me as my mental model of how EM waves work. The
universe is full of strange and fascinating processes. But if you get
back to physics, I will soon lose interest in your mind.


  #276   Report Post  
Old April 9th 06, 08:08 PM posted to rec.radio.amateur.antenna
John Popelish
 
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Default Current across the antenna loading coil - from scratch

Cecil Moore wrote:
John Popelish wrote:

I am making the point that if the displacement currents were
insignificant, outside a coax, then the speed of light for waves out
there would be infinite. And they are not, therefore those
displacement currents cannot be assumed to be insignificant.



But I am not talking about displacement currents within the
transmission line, as exists in free space. I am talking *solely*
about the displacement currents to *earth ground*. I contend that
those are often secondary effects as proven by the coax example.
Just how much displacement current to "earth ground" is there for
a coil located halfway between here and Alpha Centauri?


Almost exactly as much as there is between a coil that is a half
wavelength from a grounded surface.

Exactly the opposite. I am explaining the distributed effect of the E
field along the wave.


And completely ignoring the H-field? In the treatment of those fields,
the only variation is Z0. For EM fields, there is no "across" and no
"through". The difference between voltage and current essentially
disappears except for their Z0 ratio. The equation for current in
a transmission line is identical to the equation for voltage except
for the Z0 term. Current "drops" are commonplace in lossy transmission
lines.

For instance, what is the current at the end of 200 feet of RG-58
terminated by a 50 ohm antenna used on 446 MHz when the source
current is 2 amps?


Somewhat less then 2 amps. Loss certainly occurs along that length,
at that frequency? So what? Are you thinking that this is the
predominate mechanism that is altering the current magnitude through
your coil? It is part of the answer, but not the whole answer.

You are avoiding the very facts that would allow you to make an air
tight argument for your beliefs about "the whole point of the
discussion". You somehow picture current as a continuous thing from
one end of a conductor to the other, when it carries a traveling
energy wave. This is a misconception.


Maybe in the field of physics - not in the field of RF engineering.
For any two current points, I can calculate a point in between.
Sorry, but that's a characteristic of a *continuous* single-valued
function and can be proven mathematically. I admit to being a EE/math
major. I didn't take many pure physics courses so I am missing your
point about me being able to prove anything additional. Maybe it
will dawn on me after awhile.


That is the best outcome I can hope for.

What you don't get is, that the currents that each of those traveling
waves would have generated were localized, to begin with.


I realize that is the physicist talking and it agrees with my
earlier assertion that standing wave current doesn't flow.


No current flows. Charges flow (move) the magnitude of that movement
past any point is current. I am picking nits, here, but the
distinction is important if you want to build on these simple
concepts. By the way, I am an EE, not a physicist, but I have to
think physics to do engineering.

I guess I'm so dense that I need help in proving what you think
I can prove with that information. Right now, I am apparently
missing something, maybe because of too much California Merlot.


Sounds like something I might do, this afternoon.
  #277   Report Post  
Old April 9th 06, 08:10 PM posted to rec.radio.amateur.antenna
Cecil Moore
 
Posts: n/a
Default Current across the antenna loading coil - from scratch

John Popelish wrote:
Please forgive me for not recognizing which of the ten individual
junk yard dog "experts" is biting my ankles at any particular time. :-)


I am insulted that you include me in that derogatory characterization.
I have been polite, patient and respectful with you in this discussion.


It wasn't derogatory, John. It was a paraphrasing of the old saying:
"When one is up to one's ass in alligators, it's hard to remember
that the original purpose was to drain the swamp."

But if you get back to physics, I will soon lose interest in your mind.


I have no idea if "losing interest" is a good thing or a bad thing.
--
73, Cecil http://www.qsl.net/w5dxp
  #278   Report Post  
Old April 9th 06, 08:15 PM posted to rec.radio.amateur.antenna
Richard Clark
 
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Default Current across the antenna loading coil - from scratch

On Sun, 09 Apr 2006 18:57:55 GMT, Cecil Moore
wrote:
Whatever way you choose to "take it" has absolutely no
effect on any reality except your own personal reality
existing only in your head. Enjoy!


Odd you chose to deviate from technical discussion to explain
"seeming" in terms of fornication and masturbation. You offer no
quantifiables, and even more oddly, no qualifiables. Yours would be a
pretty strange reality.
  #279   Report Post  
Old April 9th 06, 08:15 PM posted to rec.radio.amateur.antenna
John Popelish
 
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Default Current across the antenna loading coil - from scratch

Cecil Moore wrote:
John Popelish wrote:

The definition of "local" is wavelength dependent.


Since the reality in which we exist has been proven to be
non-local in nature, I'm wondering what is your point?


Go back and ponder what I wrote.
Too much has been clipped for my elaboration to have any continuity.

Back to the RF case: Do you imagine that electrons from the source
reach the load?



Maybe for DC. But depending upon the length of the transmission
line, probably not for HF RF. Is that a rhetorical question?


It is a koan.

Someone needs to tell that to W7EL. I've tried to tell him but
instead of thanking me, he 'ploinked' me.



Perhaps he has lost interest in this thread.
Perhaps he is taking this topic personally.
Perhaps he enjoys yanking your chain.
Perhaps ...



... he is afraid of losing his "expert" status?

What does any of that have to do with our conversation?



Everything. That's what this thread is all about. I will repeat:

Can the standing wave current phase, with its unchanging phase,
be used to measure the phase shift through a wire or coil?

That's the admittedly narrow present topic. The answer is either
'yes' or 'no'. After we answer that narrow technical question,
the discussion can procede.


I have answered with my opinion on that subject many times, already.
I am trying to help you build your understanding of it, so you can
argue it more persuasively, and understand it more completely. I'm
doing it in public, to invite corrections from anyone who sees errors
in my thinking, and can explain them to me.

If you have no interest in anything but butting heads with the people
who have disagreed with you, then, please stop responding to my posts.

You have that choice.
  #280   Report Post  
Old April 9th 06, 08:39 PM posted to rec.radio.amateur.antenna
Cecil Moore
 
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Default Current across the antenna loading coil - from scratch

Richard Clark wrote:
Odd you chose to deviate from technical discussion to explain
"seeming" in terms of fornication and masturbation. You offer no
quantifiables, ...


Suffice it to say that at my age, the quantifiables are not
what they used to be. :-)
--
73, Cecil http://www.qsl.net/w5dxp
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