Loading Coils; was : Vincent antenna
 

On Tue, 18 Dec 2007 03:07:30 GMT, Cecil Moore
wrote:

Richard Clark wrote:
At the fear of being presumptions, why don't you move the source 77
degrees along the radiator?

I don't think that will make Roy's statement true.

Roy said:
"The current reported by EZNEC isn't referenced to source phase."

Still confused? Who is talking about source phase? And why?

This must sting, the start of another round of 20 questions to measure
the depression of your attention deficit, when you could have as
easily informed us all what you meant before having to be prompted.

Loading Coils; was : Vincent antenna
 

On Mon, 17 Dec 2007 22:09:16 -0500, "AI4QJ" wrote:

When you do that, how does this show up in the coordinates?

Hi Dan,

Mathcad allows for as many coexisting simultaneous axis as you care.

As for 3D, this is called a contour plot (which can be done either
flat, or with relief). Excel will do this too (but with no particular
panache).

Seeing you are funds challenged, search the web for OpenDX (an IBM
project deeded to the public domain, and otherwise called Data
eXplorer). It can do the same thing. There is also a package called
XD3D, that is also from the OpenSource community.

The IBM package is the one most used by the research community; or at
least the ones I've been attending for 7 years.

73's
Richard Clark, KB7QHC

Loading Coils; was : Vincent antenna
 

On Dec 18, 2:33 am, Richard Clark wrote:
On Mon, 17 Dec 2007 22:09:16 -0500, "AI4QJ" wrote:
When you do that, how does this show up in the coordinates?

Hi Dan,

Mathcad allows for as many coexisting simultaneous axis as you care.

As for 3D, this is called a contour plot (which can be done either
flat, or with relief). Excel will do this too (but with no particular
panache).

Seeing you are funds challenged, search the web for OpenDX (an IBM
project deeded to the public domain, and otherwise called Data
eXplorer). It can do the same thing. There is also a package called
XD3D, that is also from the OpenSource community.

The IBM package is the one most used by the research community; or at
least the ones I've been attending for 7 years.

73's
Richard Clark, KB7QHC

I already know what a static 3D plot would like like. But to put it in
motion, including the illustration of the forward and reflected length
over distance x; showing the surface of periodic waves for each value
of x; that would be a nice visual.

Loading Coils; was : Vincent antenna
 

AI4QJ wrote:
I
myself would never attempt to observe the cat in Schrodinger's box since it
is not definitive of the state of the cat prior to observation. I do not
believe the same is true of the -j567 ohm impedance in Keith's box ;-)

In the real world, the person who manufactured our
black box in the first place has already collapsed the
probability function a long time ago. Now if that
person dies without telling anyone what's in the black
box, does the black box's contents revert to any
possibility? :-)

The difference is that Schrodinger's cat can die at any
time but the inanimate contents of our black box cannot
change with time. If we don't know what's in the black
box, we are simply ignorant. What we know or don't know
does not effect or affect the reality of what's already
in the black box.
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Roy Lewallen wrote:
The current reported by EZNEC isn't referenced to source phase. The
phases of all currents and voltages -- wire, source, and load -- are all
referenced to the same arbitrary point. Source phase can be assigned by
the user to any value relative to this point.

I'm sorry, Roy, I just changed the source phase in a single
source system and changed nothing else. The reported phase of
the antenna currents changed in step with the source phase.
Since all you did was provide a GUI interface to NEC, might
it be possible that you don't understand how NEC works?
--
73, Cecil http://www.w5dxp.com

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:

I'm not reporting the results, Jim. EZNEC is reporting
the results.

To my knowledge EZNEC has never reported a single result to this
newsgroup, Cecil.

Choose the "Loads Dat" display.

http://www.w5dxp.com/coil512.ez

http://www.w5dxp.com/travstnd.gif

Have you ever even looked at those files?

I looked at travstnd the first time you posted it, and I even
commented to you about it. I assume that coil512.ez is what you used
to create the plot on the left that says "No Phase information in the
Magnitude" and has the words "Straight Line" by the straight line.
It's all very scientific. :-)

Let me ask you this: how would you go about calculating the phase
shown on your Standing Wave Current graph, and what meaning if any
does it hold for you?

73, ac6xg

Loading Coils; was : Vincent antenna
 

Cecil Moore wrote:
Roy Lewallen wrote:
The current reported by EZNEC isn't referenced to source phase. The
phases of all currents and voltages -- wire, source, and load -- are
all referenced to the same arbitrary point. Source phase can be
assigned by the user to any value relative to this point.

I'm sorry, Roy, I just changed the source phase in a single
source system and changed nothing else. The reported phase of
the antenna currents changed in step with the source phase.
Since all you did was provide a GUI interface to NEC, might
it be possible that you don't understand how NEC works?

Cecil,

I think you are misunderstanding Roy's response. If the currents were
referenced to the source phase, they would not change when the source
phase was changed. That observable fact that the antenna current phases
do change when the source phase is changed supports Roy's explanation
completely.

73,
Gene
W4SZ

Loading Coils; was : Vincent antenna
 

On Tue, 18 Dec 2007 11:03:53 -0800 (PST), wrote:

On Dec 18, 2:33 am, Richard Clark wrote:
On Mon, 17 Dec 2007 22:09:16 -0500, "AI4QJ" wrote:
When you do that, how does this show up in the coordinates?

Hi Dan,

Mathcad allows for as many coexisting simultaneous axis as you care.

As for 3D, this is called a contour plot (which can be done either
flat, or with relief). Excel will do this too (but with no particular
panache).

Seeing you are funds challenged, search the web for OpenDX (an IBM
project deeded to the public domain, and otherwise called Data
eXplorer). It can do the same thing. There is also a package called
XD3D, that is also from the OpenSource community.

The IBM package is the one most used by the research community; or at
least the ones I've been attending for 7 years.

73's
Richard Clark, KB7QHC

I already know what a static 3D plot would like like. But to put it in
motion, including the illustration of the forward and reflected length
over distance x; showing the surface of periodic waves for each value
of x; that would be a nice visual.

Hi Dan,

I've already offered that solution. I have been using OpenDX to do
this for some time now. Have you looked at my suggestions?

73's
Richard Clark, KB7QHC

Loading Coils; was : Vincent antenna
 

On Dec 16, 9:06 am, Cecil Moore wrote:
Keith Dysart wrote:
Why would anyone refuse to calculate the length of
600 ohm line needed to produce 0 ohms? I think I
was the first to calculate it at 43.4 degrees.

So the next question is: What is the phase change
at the terminals of the black box?

1) -93 degrees? (previous answer when it was a capacitor)

I might be wrong about that one. It might instead be
180 - 93, but that would just be a stupid math mistake.
The main thing is that it is different from the other two.

2) 36.6 degrees? (previous answer when it was 10 degrees of 100 ohm
line)
3) 0 degrees? (previous answer when it was 46.6 degrees of 600 ohm
line)

There's nothing wrong with those answers except maybe
a stupid math error. Each condition indeed does have a
different phase shift that can be measured one inch on
the other side of the terminals if one is simply allowed
to make those measurements.

But the rules for black boxes do not allow measurements
on the inside. This is how they help clarify the thinking.

This is an example of how models can get you into trouble.
Not allowing us to look inside the black box doesn't change
the laws of physics and make all the phase shifts the same.

Nor has that been claimed.

It just means that the phase shifts are unknown and need
to be measured.

As you say, the phase shifts are unknown so from
my list of possible answers, I would have recommended
selecting

4) undecidable

but this leads to it also being

6) irrelevant

since the problem can be solved without the information.

....Keith

Loading Coils; was : Vincent antenna
 

On Dec 16, 9:24 am, Cecil Moore wrote:
Keith Dysart wrote:
So the next question is: What is the phase change
at the terminals of the black box?

It just occurred to me that you and I may be talking
about two different phases.

---Z01---+---Z02---

Vfor1--|--Vfor2

Vref1--|--Vref2

I am talking about the phase shift in the forward waves
across the impedance discontinuity, i.e. the phase shift
between Vfor1 and Vfor2. The list of phase shifts is
the phase shift in the forward voltages at the impedance
discontinuity. It is different for all the black boxes.

If you are talking about the phase between Vfor1 and Vref1,
then, yes, that phase is the same for all the black boxes.
It is impossible for it to be otherwise.

I do think I was keeping them straight, though the
mention of 90 degrees of phase shift in the same
sentences occasionally required close reading.

....Keith