LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #20   Report Post  
Old January 10th 09, 09:46 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Mar 2008
Posts: 1,339
Default Does NEC-2 model wires as solid or hollow?

On Jan 10, 12:32*pm, "Frank" wrote:
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.


You appear to be confused with the defininition of the integral. You
simply integrate the function over the desired range, and should not be
concerned with irrelevant concepts, such as strip widths.

If the area represented a cross section of a radiator the thickness of
that strip is then a problem.


No such strip exists in integration.

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


Not so; "dx" simply refers to the independant variable to be integrated.
Note the first example of a "Reimann integral" at:http://mathworld.wolfram.com/Integral.html

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.


To determine the RF resistance of a conductor requires a
solution involving "Kelvin/Thompson" functions; which are
modified Bessel functions with a complex argument. *See the
following for details:http://www.st-andrews.ac.uk/~www_pa/...kineffect/page...
Also:http://mathworld.wolfram.com/Bei.htm...m.com/Ber.html

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.


Ansoft's (www.ansoft.com) "Maxwell" is a "Finite Element Modeling"
(FEM) program which, among other things, can accurately produce
a graphical representation of the current distribution in a cylindrical
conductor. *See examples at:http://www3.telus.net/nighttrainexpr...in%20depth.htm
These graphs are reproduced from an article in the November/December
issue of QEX magazine, pp20 - 29, by Rudy Severns, N6LF.

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.


Sorry, I don't mean to be insulting, but I am baffled how you can
have such problems with elementary math; yet argue about
concepts taught in a third year electrical engineering degree
program with prerequisites in advanced calculus, partial differential
equations, and more.


Frank
I understand that you are baffled. I retired early from GE with a
heart attack which was then followed by a series of operations before
I again had a open heart op with 5 bypasses plus
and a few other side problems. My first heart attack to my memory
away, could not even read beyond one line. So I focussed on antennas
to keep myself alive and to reroute my brain.
With my tunnel vision retraining over the last decade plus I regained
a tunnel type memory where I focussed solely on antennas. With my
present project I have had to retrain in various aspect which required
leapfrogg some of the basics but with ten plus years of work, 3 steps
forward and two steps back I now consider myself something of an
expert on a subject which is long and deep but narrow in span. On my
antenna concept I am absolutely sure regarding what I have found, even
sought confirming examination but when I venture off channel with
respect to this group I go wonky
I believe that because of the latter my credibility suffers when I
communicate which energises a trend to insult rather than to take an
effort to follow what I have done and rechecked an unknown amount of
times over the years. Thus with the concept that all is known and if I
am correct it would have been done 100 years ago rises to the top
while ignoring things from my side that I have to
learn and review everything from first principles while using the
tools of today.
The first patent has been printed and will soon b e reviewed which
also includes a description from the times of Gauss. I look forward
to that time as it will pull into the open my discoveries.
In the mean time I will contunue to make my point on the newsgroup.
Main problem is that many have a antenna program but it apears none
have the more expensive optimizer and none have used the free versions
that are available. So the proof provided by NEC2 and 4 and mininec
is beyond this groups ability to come to grips with. The bottom line
is all povide the superior results
of tilted antennas thus the descision has to be made that all programs
are totally in error or all are
satisfactor descision that this group is not equipped to address. If
you want to follow my line of thinking because of my lapses into the
wonky side you can always use E mail rather than subject yourself to
the whims of the group. The bottom line of all this is that a
directional antenna for 160 metres is now available to which all hams
are anxious to avoid at all costs or to debunk all thoughts of
acceptance as all is known.
Best regards
Art










I really believe that the answer lays on Maxwells laws and not with
the approximation supplied by Uda/Yagi.


I agree, but Yagi and Uda simply build experimental models. *Which
is about all anybody could do in those days.

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.


Many hams interested in low frequency DX use sloping (monopole) radiators,
which gives a slight improvement in low angle radiation.

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.


Sorry, but you lost me again.



FRANK
When the leading edge of the half cycle reaches the open end of the
antenna the descision has to be made with the direction of movement.
Tradition is that current flows in a closed loop thus the descision is
between two or three routes
1 Capacitive coupling to ground as shown in some books to complete a
circuit
2 Turn around by ducking under the skin of the radiator to complete a
closed circuit
3 Invent a open circuit current flow which by turning around confronts
its own tail which is producing
the eddy current resistance in the skin as it is yet to reach the end
of the radiator.
From my point of view the leading edge cannot continue radiating or it
will become a full size radiator. The material under the skin depth is
an extremely low resistance path which cannot support the formation
of eddy current as it has no access to a dialectric (air). This
descision
also will not stray from the closed circuit traditions.
Now for the final eye popper, If a radiator is not in equilibrium
there is a literal current flow on the outside which by the standard
laws requires a literal current flow in the opposite direction.
Prior to the discovery of the eddy current users placed the return
current in the air which prevented true understanding of radiation by
using this flow as justification for radiation being produced by waves
which was then extrapolated to prove that light was a matter of waves.
What I am asking for is a acceptance of particles at rest from the sun
as being the true transportation of radiation which aligns directly
with the suns rotation and the use of levitation of the particles from
diamagnetic materials such as aluminum correr etc which cannot retain
magnetism in the same proven methos used around the World when sorting
and separating
materials in all the scrapyards,.As far as acceptance of particles
emminating from nuclear burning of the sun in line with a cycle and
their high density presence on Earth with the affinity for atraction
for diamagnetic materials that has been accepted fully in the last few
years in many reseach labs
in many diffgerent countries except....except... on this newsgroup
Art



73,

Frank




 
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
Building a Solid Copper Ground Pipe {Tube} with an Solid Iron Core. - Also - Water Drilling a Solid Copper Pipe for a Ground Rod. RHF Shortwave 12 January 17th 06 07:39 PM
Building a Solid Copper Ground Pipe {Tube} with an Solid IronC... [email protected] Shortwave 0 January 16th 06 10:04 PM
Building a Solid Copper Ground Pipe {Tube} with an Solid IronC... [email protected] Shortwave 0 January 16th 06 09:57 PM
Hollow State Newsletter is now online Les Shortwave 2 August 25th 05 03:36 PM
Hollow state news Beerbarrel Boatanchors 0 August 23rd 05 09:39 PM


All times are GMT +1. The time now is 06:36 PM.

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