On Jan 7, 4:21*pm, "Dave" wrote:
"Richard Fry" wrote in message

...
On Jan 3, 10:37 am, Art Unwin *wrote:

There is absolutely NO evidence that
reflection occurs in any shape or form at the
material ends of a radiator and all that pertains
to such. PERIOD.
Art, the link below leads to empirical proof that such reflections
exist.

don't confuse him with facts, especially facts out of books... they are all
out of date since they don't have his latest theories included in them.


If graphs of current flow is to be generated it must provide a graph
of the lead edge of the current to compare with the trailing edge at
an instant of time, because it is a time varing current.

For a fractional wave antenna skin depth or resistance on the surface
does not disappear until the trailing edge of the RF pulse reaches the
antenna top. In the mean time current rises at the top as the fields
collapse which means that the lead current is prevented from turning
around because skin resistance is still being maintained Thus it has
no other choice to pursue a closed circuit other than travel on the
inside of the radiator and being shielded by the surface eddy currents
produced by the trailing current end.
If by some phenoma the current was able to flow down the outside of
the radiator it must also produce eddy current which thus allows for
radiation from what originaly was a puise to a duallity of current
flow, each of which creating radiation without frequency remaining
constant.
There is no reasonable reason to depart from the closed circuit ideals
to manufacture an incomplete sequence of events not supported by
science but printed in books. Otherwise there will be no progress in
the understanding of radiation until the actions of eddy current or
the weak force is fully understood with its ejection of particles from
diamagnetic materials.
I will not add to this thread as it is surround by closed minds of the
aged.
Have a great day
Art Unwin......KB9MZ.....xg

don't confuse him with facts, especially facts out of books... they are
all out of date since they don't have his latest theories included in
them.

I think he is laughting at us all, and just seeing what can be gotten away
with.
Nobody with an engineering degree would ever write something like the
following:

"Calculus is based on homogenous materials or planes where you can
refer dy/dx to some thing aproaching zero. In the case of using this
aproach where the antenna diameter aproaches zero this is an invalid
aproach for accuracy but O.K. for aproximations. So much for the
foibles of theoretical mathematics".

On Jan 8, 3:57*pm, Art Unwin wrote:
If graphs of current flow is to be generated it must provide a graph
of the lead edge of the current to compare with the trailing edge at
an instant of time, because it is a time varing current.

Art -
In your perception you have merged my r-f pulse measurement link with
my link to a relevant I.R.E. paper by Gihring & Brown of RCA.

But while both of these links show the existence of reflections, they
can not be combined in any manner to reach the conclusion stated in
your post clip quoted above.

Regardless of that, you continued your post with...

For a fractional wave antenna skin depth or resistance on the surface
does not disappear until the trailing edge of the RF pulse reaches the
antenna top. In the mean time current rises at the top as the fields
collapse which means that the lead current is prevented from turning
around because skin resistance is still being maintained. Thus it has
no other choice to pursue a closed circuit other than travel on thenside
of the radiator and being shielded by the surface eddy currents
produced by the trailing current end. etc

Art, consider just the Gihring/Brown measurements linked to earlier in
this thread. They were made using a continuous, non-pulsed r-f
waveform, so none of your beliefs posted above will apply.

Yet the current distribution measured along the lengths of those
radiators by Gihring/Brown proves the existence of reflections from
the end of such radiators, and that such reflected r-f current does
not return from the end of such radiators via a non-radiating path
through the center of the same conductor, as you suppose.

I will not add to this thread as it is surround by closed minds of the aged.

But not for the reason you state next above, I'd wager.

RF

"Richard Fry" wrote in message
...
On Jan 8, 3:57 pm, Art Unwin wrote:
If graphs of current flow is to be generated it must provide a graph
of the lead edge of the current to compare with the trailing edge at
an instant of time, because it is a time varing current.

Art -
In your perception you have merged my r-f pulse measurement link with
my link to a relevant I.R.E. paper by Gihring & Brown of RCA.

But while both of these links show the existence of reflections, they
can not be combined in any manner to reach the conclusion stated in
your post clip quoted above.

Regardless of that, you continued your post with...

For a fractional wave antenna skin depth or resistance on the surface
does not disappear until the trailing edge of the RF pulse reaches the
antenna top. In the mean time current rises at the top as the fields
collapse which means that the lead current is prevented from turning
around because skin resistance is still being maintained. Thus it has
no other choice to pursue a closed circuit other than travel on thenside
of the radiator and being shielded by the surface eddy currents
produced by the trailing current end. etc

Art, consider just the Gihring/Brown measurements linked to earlier in
this thread. They were made using a continuous, non-pulsed r-f
waveform, so none of your beliefs posted above will apply.

Yet the current distribution measured along the lengths of those
radiators by Gihring/Brown proves the existence of reflections from
the end of such radiators, and that such reflected r-f current does
not return from the end of such radiators via a non-radiating path
through the center of the same conductor, as you suppose.

I will not add to this thread as it is surround by closed minds of the
aged.

But not for the reason you state next above, I'd wager.

RF

of course not, you have shown him real facts... he can't fight real facts,
they just confuse him, so he'll go away and come back later and say that you
were completely wrong and that he proved it. and then go right back to
spouting the same old magical levitating diamagnetic neutrino bafflegab.

On Jan 8, 6:14*pm, Richard Fry wrote:
On Jan 8, 3:57*pm, Art Unwin *wrote:

If graphs of current flow is to be generated it must provide a graph
of the lead edge of the current to compare with the trailing edge at
an instant of time, because it is a time varing current.

Art -
In your perception you have merged my r-f pulse measurement link with
my link to a relevant I.R.E. paper by Gihring & Brown of RCA.

Your posting was incomplete leaving more questiios than answers other
than the answers you applied so I obsoleted it.
I have have had not connection whatever , to my knowledge. of any
paper by Gihring and Brown
thus there is no reason for communication between us.
I say something and the reaction of the group states you can't. I have
no control how others think
so I move along on my own until something relevant comes along to
which I can apply a semblance of logic.







snip


I will not add to this thread as it is surround by closed minds of the aged.

But not for the reason you state next above, I'd wager.

RF

On Jan 8, 4:44*pm, "Frank" wrote:
don't confuse him with facts, especially facts out of books... they are
all out of date since they don't have his latest theories included in
them.

I think he is laughting at us all, and just seeing what can be gotten away
with.
Nobody with an engineering degree would ever write something like the
following:

"Calculus is based on homogenous materials or planes where you can
refer dy/dx to some thing aproaching zero. In the case of using this
aproach where the antenna diameter aproaches zero this is an invalid
aproach for accuracy but O.K. for aproximations. So much for the
foibles of theoretical mathematics".

Frank
You know that the term of dy/dx is absent of metrics unless limits are
applied.
If the object is to measure the plane at hand it obviously must
represent a homogeneous plane
when the limits applied. This was established long before I was born
so it was not I who made it up
Laugh away it is good for you.
Art

On Jan 2, 6:31*pm, wrote:
I've been using 4Nec2, a freeware antenna modeling program based on
NEC-2 (Numerical Electromagnetic Code). I'm wondering if anyone could
provide some insight as to just how it models current at the ends of
wires that are not connected to anything (a.k.a. "free ends" or "open
ends").

Does NEC-2 model "end caps" at free ends, which is equivalent to
assuming wires are solid, or does it just set the current equal to
zero at the free ends, which is equivalent to assuming wires are
hollow? Is it possible that it does both, but the specific model is
determined by the choice of computational kernel (extended vs.
standard)?

I've tried looking through some of the NEC-2 documentation, but I
can't find a definitive answer.

-Dave, K3WQ

David
I see no reference with respect to the ratio between diameters so It
must reflect
solid conductors. If the elements were hollow there could be current
flow within the tube together with skin depth. However, the
communication must be consistent with straight line projectory and
thus the center of the tube would act like a Faraday cage. This is
different to current flow in the center of a solid radiator since
there can be no eddy current within a material of a RF radiator.
Remember, no matter how you read the NEC files equations arrived at
are often approximations since many time portions of equations are
assumed to be negligeable compared to the overall scheme of things and
thus deleted. Do that a few times and it is not known whether the
solutions is a greater or smaller approximation , only a closer
approximation that that created by a planar design. As a U.S.Senator
from Illinois once stated, a dollar here and a millions there and
pretty soon we are talking about real money (Sen Dirksen of Peoria)
Regards
Art

Art Unwin wrote:

You know that the term of dy/dx is absent of metrics unless limits are
applied.

Bassackwards as usual.

dy/dy is differentiation, it is integration that has limits.


--
Jim Pennino

Remove .spam.sux to reply.

Frank
You know that the term of dy/dx is absent of metrics unless limits are
applied.
If the object is to measure the plane at hand it obviously must
represent a homogeneous plane
when the limits applied. This was established long before I was born
so it was not I who made it up
Laugh away it is good for you.
Art

Your terminology is confusing: "The term of dy/dx". What does "term"
mean? How is it absent of metrics? I assume by "Metrics" you mean
a numeric value. dy/dx implies there is a function: y = f(x), for which
the derivative, f '(x) exists. The calculation of a derivative is trivial,
and assigning a numeric result simply involves substituting in
f ' (x) at x = a. I don't understand what you mean by applying limits
to a derivative. As long as the function is continuous, then the
derivative exists. Are you considering the "Newton Quotient"?
Why is the Newton Quotient relevant, when simple differentiation
methods will achieve the same answer.

What are you measuring in a plane? A plane is represented by a
linear equation in x, y, and z: such as:
a(x - xo)+b(y - yo)+c(z - zo) = 0. The coefficients a, b, and c
are a set of direction numbers of a normal to the plane.
Taking the derivative (dy/dx) of such a function implies a
"Partial" derivative, such that the "z" terms vanish, and you are
left with an equation of a line y = m*x+b, where the solution
is obviously "m". As for the homogeneity of a plane; you are introducing
a 4th dimension. What is the 4th variable? Subject to partial
differentiation
with respect to x; the 4th variable disapears anyway.

Did I get it right? I find the way you explain math is very difficult for
me to follow. Note: I am not laughing at you -- I assume you are
laughing at us who respond.

Frank

On Jan 8, 9:10*pm, "Frank" wrote:
Frank
You know that the term of dy/dx is absent of metrics unless limits are
applied.
If the object is to measure the plane at hand it obviously must
represent a homogeneous plane
when the limits applied. This was established long before I was born
so it was not I who made it up
Laugh away it is good for you.
Art

Your terminology is confusing: *"The term of dy/dx". *What does "term"
mean? *How is it absent of metrics? *I assume by "Metrics" you mean
a numeric value. *dy/dx implies there is a function: y = f(x), for which
the derivative, f '(x) exists. *The calculation of a derivative is trivial,
and assigning a numeric result simply involves substituting in
f ' (x) at x = a. * I don't understand what you mean by applying limits
to a derivative. *As long as the function is continuous, then the
derivative exists. *Are you considering the "Newton Quotient"?
Why is the Newton Quotient relevant, when simple differentiation
methods will achieve the same answer.

What are you measuring in a plane? *A plane is represented by a
linear equation in x, y, and z: such as:
a(x - xo)+b(y - yo)+c(z - zo) = 0. *The coefficients a, b, and c
are a set of direction numbers of a normal to the plane.
Taking the derivative (dy/dx) of such a function implies a
"Partial" derivative, such that the "z" terms vanish, and you are
left with an equation of a line y = m*x+b, where the solution
is obviously "m". *As for the homogeneity of a plane; you are introducing
a 4th dimension. *What is the 4th variable? *Subject to partial
differentiation
with respect to x; the 4th variable disapears anyway.

Did I get it right? *I find the way you explain math is very difficult for
me to follow. *Note: I am not laughing at you -- I assume you are
laughing at us who respond.

Frank

No Frank I was careless.
When you are determining the area under a curve, the curve has an
equation
When the graph is roughly drawn out you draw a narrow vertical strip
that represents dy/dx
That strip has no specific thickness as it represents a vanishingly
thin strip.
If the area represented a cross section of a radiator the thickness of
that strip is then a problem.
As a radiator dx could represent the skin depth or it could represent
the distance from the surface to the center line and thus the cross
section would not be homogenous, same density etc
The problem then becomes what is the true skin depth density in
relation to the inner core which allows for the application of the
material resistance.
Now I see skin depth as the point that eddy current becomes a
contained current circuit without discontinuity. The books define skin
depth as a relation of decay which is not how I see things so we have
a difference in proving things one way or the other. I then added
aunconnected problem by drifting towards integration and limits ie
travelling back from integration to the differation format which was a
silly mistake for which I have been already reprimanded by the nets
monitor who looks out for those things rather than the technical
content. I really believe that the answer lays
on Maxwells laws and not with the approximation supplied by Uda/Yagi.
Computor programs say the same thing via the tipping radiator which
all deny so there is no possible solution to be arrived at that
satisfies all unless somebody provides answers that reflect Maxwell
and not Yagi/Uda rather than "I said so" as every thing is known and
is in the books that I own. At no time have I taken your postings as
mocking or otherwise insincere as you are the only person who used a
antenna program in conjuction with my beliefs which shows radiators as
not being parallel with the surface of the Earth where others refused
to check in any way. As I stated in an earlier posting one must graph
the current levels at the top of a radiator by superimposing both
graphs where both the leading and trailing currents arrive at the end
( time separation of half a period)so that current direction can be
determined since in one case there is no eddy current and the other
case does have eddy currents( flow resistance) on the surface which
thus determines current flow direction at each point.
Best regards
Art