RadioBanter - Lumped Load Models v. Distributed Coils

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- - Lumped Load Models v. Distributed Coils (https://www.radiobanter.com/antenna/1140-lumped-load-models-v-distributed-coils.html)

Art Unwin KB9MZ wrote:
However he has rejected this aproach.

Art, just because I don't buy a Big Mac today doesn't mean
that I reject Big Macs. I was just in the mood for an egg
sandwich on cinnamon-raisin toast.
--
73, Cecil http://www.qsl.net/w5dxp

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Cecil
I understand what you are saying but it is still a rejection
That seems to follow a general pattern of late where a stance is taken and
all else is rejected sometimes without cause. In this particular case Bart
also brought the same subject ( at least I think he did) as something to
ponder about and on this very same thread. where you supplied drawings of
collinear dipoles.
I admit not being able to follow a lot of the to and fro auguements about
contraflow movements e.t.c. which to me is the study of individual movements
by tracking footprints after the Mall has closed which provides little
benefit , but surely Bart's posting gives you something to ponder upon as
your present stance has not won over any converts and which could possibly
be presented in a different manner to make your case more digestable.
Anyway, I bow to your more intimate knowledge of the subject of inductance
and that the inclusion suggested adds no value.

Best regards
Art

"Cecil Moore" wrote in message
...
Art Unwin KB9MZ wrote:
However he has rejected this aproach.

Art, just because I don't buy a Big Mac today doesn't mean
that I reject Big Macs. I was just in the mood for an egg
sandwich on cinnamon-raisin toast.
--
73, Cecil http://www.qsl.net/w5dxp

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On Sat, 31 Jan 2004 19:20:18 GMT, Gene Fuller
wrote:

|Yuri,
|
|You are absolutely correct; this thread has drifted beyond recognition.

Actually, as threads go this one isn't all the bad. As the originator
of the thread I believe I know what the topic is.

Yuri can claim that this is away from the "original problem", however,
the original problem, as he calls it, wasn't the topic of the paper to
which my original posting pointed.

|
|Please note that I have never questioned your experiment or your data. I am
|merely commenting on the highly unscientific handwaving approach taken RRAA's
|most prolific "scientist".
|
|73,
|Gene
|W4SZ
|
|Yuri Blanarovich wrote:
|This has become unusually entertaining.
|....... snipydyduda
|However, I do not believe I have ever encountered a "scientist" who rejected
|both experimental and mathematical approaches at the same time.
|
|73,
|Gene
|W4SZ
|
|
|
|
|
| Hey,
| this is getting off on the tangent, away from the original "problem".
| I and Barry W9UCW found, measured differences in the typical loading coil
| currents in order of 40 - 60%. See article and pictures on my web www.K3BU.us.
| W8JI and flat earth society proclaimed it can't be so. They argued and
| "calculated" that current at both ends of a loading coil in quarter wave loaded
| radiator has to be the same. W5DXP explained why the current is different,
| other sources and past publications affirm that.
|
| As I mentioned, time permitting, I will put together article explaining what is
| happening, describe experiments that can be replicated by non-believers and
| elaborate on the significance of the effect on the design of shortened (loaded)
| antennas.
|
| Nobody has argued the seven points I raised earlier, and those who measured,
| including W8JI found that current IS different (but still says it is NOT).
|
| The reality is that current is different, Eznec can't model it, you can
| speculate and theorize all you want, it will not revert the Earth to be flat.
| Big men will admit they were wrong, thank the enlighteners and RF life goes on.
|
| Yuri, K3BU.us

On Sat, 31 Jan 2004 08:04:47 -0600, Cecil Moore
wrote:

|Wes Stewart wrote:
|
| wrote:
| |Don't know how. But assuming I can learn how to do that in HTML, I'll
| |try to post those files tomorrow.
|
| As you can see from my home page I'm not, nor do I want to be, a web
| page designer. But even I know that you can just ftp your files to
| your web page. You don't need to create a link on a page, just tell
| us the file name. I do it all the time.
|
|Thanks for the tips, Wes, and it does work. The names of the .EZ files
|are on the .gif graphic that I prepared which illustrates the current
|magnitudes and phases for 3/2WL phased arrays.
|
|http://www.qsl.net/w5dxp/phasesbw.gif

I downloaded a couple of them, but I have a question. I opened them
using MultiNEC, which reads all of the popular modeling program file
formats. The loads did not import, but when I opened the same files
in EZNEC 3 I saw them as R+jX loads with only an 'X' value.

I learned from Dan, AC6LA, the author of MultiNEC, that some early
EZNEC versions save all loads as Laplace and he doesn't read those
into MultiNEC. Opening the files in EZNEC 3 and then just resaving
them makes the import into MultiNEC work okay, but this makes me
suspect that using your earlier files in my later version might be a
problem. The documentaion says otherwise though, but to be sure, what
are the actual load parameters.

I don't want to comment further until I know exactly what you are
using.

Bart Rowlett wrote:

Thanks, Bart. [Lots of good stuff trimmed.]

In reality, the common mode impedance to ground of an isolated LC
circuit is not infinite. Both the inductor and capacitor have
capacitance to space which will provide some 'grounding' effect. At
MF through VHF, the components would generally need to be physically very
large to have a usefully low common mode impedance to ground however.

Seems that answers the phase-reversing coil question. It has to be
physically very large. As Kraus suggested, a 1/2WL element coiled up
would necessarily be physically very large. It would actually be the
physical size of a 1/2WL helical antenna. A pancake coil might work
well in that situation. My 75m Texas Bugcatcher coil is also physically
very large.
--
73, Cecil http://www.qsl.net/w5dxp
"One thing I have learned in a long life: that all our science, measured against
reality, is primitive and childlike ..." Albert Einstein

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I think that there is more to Bart's posting than that!

First the idea given by certain people to model
by breaking up the inductance into small parts
is nothing but crap and suedo scientific hoodwinking.

Since inductance in a coil per unit length is not uniform
( Reg alluded to this also )
any breaking up into parts involves an increase in inductance to maintain
resonance. Thus the aproach does nothing more than break up a large part as
a means for scientific hood winking for the unsuspecting to assist
digestion.
It does nothing to bring a dimension less lumped load
to an item of the real world which requires a fully dimensioned item.or it's
equivalent.

If the inductance were to be resonant then it can certainly be replaced by a
parallel loop circuit of size of the original real world inductance and
where current in versus current out can be ascertained together with any
phase when
ground is placed in the required position.. The same aproach also covers the
actual placement of the coil
on any vertical radiator since resonance must be maintained

To consider this discussion in any other way is totally pointless and thru
time obscures the original intent of the post.and where certain obduration
rather than education prevails

Best regards
Art Unwin KB9MZ....XG

"Cecil Moore" wrote in message
...
Bart Rowlett wrote:

Thanks, Bart. [Lots of good stuff trimmed.]

In reality, the common mode impedance to ground of an isolated LC
circuit is not infinite. Both the inductor and capacitor have
capacitance to space which will provide some 'grounding' effect. At
MF through VHF, the components would generally need to be physically
very
large to have a usefully low common mode impedance to ground however.

Seems that answers the phase-reversing coil question. It has to be
physically very large. As Kraus suggested, a 1/2WL element coiled up
would necessarily be physically very large. It would actually be the
physical size of a 1/2WL helical antenna. A pancake coil might work
well in that situation. My 75m Texas Bugcatcher coil is also physically
very large.
--
73, Cecil http://www.qsl.net/w5dxp
"One thing I have learned in a long life: that all our science, measured
against
reality, is primitive and childlike ..." Albert Einstein

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Art Unwin KB9MZ wrote:
I think that there is more to Bart's posting than that!

Of course there is, Art. I just chose to reply to one topic. I respect
Bart not only because he is brilliant and knowledgeable, but because he
doesn't engage in ad hominem attacks like some other people I know.

That being said, I don't think a ground is necessary to cause a phase
reversal. A 2WL centerfed dipole has phase reversals even when positioned
in free space. I don't see any reason to suspect that a 2WL centerfed
helical dipole doesn't exhibit the same phase reversals. If you replace
the helical on each side of the phase reversals by straight wires, I don't
think the phase reversal will magically disappear in the part of the helical
antenna coil that remains. I could be wrong, but common sense seems to work
pretty well in the area of antennas (if not for QED. :-)
--
73, Cecil http://www.qsl.net/w5dxp

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On Sun, 01 Feb 2004 16:49:39 GMT, " Art Unwin KB9MZ"
wrote:
First the idea given by certain people to model
by breaking up the inductance into small parts
is nothing but crap and suedo scientific hoodwinking.

Art,

As usual you are long on condemnation, and short on facts.

73's
Richard Clark, KB7QHC

"Cecil Moore" wrote in message
...
Art Unwin KB9MZ wrote:
I think that there is more to Bart's posting than that!

Of course there is, Art. I just chose to reply to one topic. I respect
Bart not only because he is brilliant and knowledgeable, but because he
doesn't engage in ad hominem attacks like some other people I know.

Now that Cecil I heartedly agree with, kudo's to Bart
since the trend is to attack the man to cover ones inadequacies with respect
to the subject at hand.

That being said, I don't think a ground is necessary to cause a phase
reversal. A 2WL centerfed dipole has phase reversals even when positioned
in free space. I don't see any reason to suspect that a 2WL centerfed
helical dipole doesn't exhibit the same phase reversals.
**
Cecil you are trying to jump the Grand Canyon it two jumps by looking at
phase angle alone for picture purposes rather than have the total picture
for overall analysis.
**
If you replace
the helical on each side of the phase reversals by straight wires, I don't
think the phase reversal will magically disappear in the part of the
helical
antenna coil that remains. I could be wrong, but common sense seems to
work
pretty well in the area of antennas (if not for QED. :-)
**
Well common sense can also be intuitive sense which can be in error by 180
degrees. to common people that does not have the backing of MENSA
The point I am trying to make is to stay on track with the subject that was
raised in the first place as many have now forgotten what the initial point
is thus the reactions that are not pertinent.
The statement presented by your own hand stated that eznec cannot model it
thus leading to conjecture. That you will object to since you are confident
by virtue of some aquired knoweledge but has no value unless that analysis
is shared by all, and that is clearly not so which has led to wierd
suggestions and semantics to overcome that obstacle. My point is that
understanding and agreement will only come when clarity is applied as to why
Eznec cannot solve the problem. and replace it.
It is evident that Eznec cannot deal the way we want with lumped loads, but
it is also incapable of working backwards in a complex circuitry mode to
formulate
an equivalent circuit. This is because the program is reactive rather than
proactive with respect to radiation.
To be proactive one must be able to transform radiation resistance to many
other forms of resistance i.e. skin resistance, coupling and the like
.. Fortunately there are other programs out there that can work backwards
from lumped loads complex circuit style that can do this ensuring that
radiation efficiency is emulated in its entirety.
Thus I and I suspect Bart also and not forgetting Reggies comment regarding
what every body is ignoring, that for clarity sake to ensure that all are
paddling in the same boat is to basically put the inductance as an
equivalent circuit in a ' black box" where entry and exit parameters can be
compared in a logical manner instead of falling back on 'common sensen
So I am calling for collective analysis instead of raising ones voice when
talking to someone who does not know your language.
Nothing personal and I am not pointing fingers,but I fear that most are in
different boats and paddling in multiple direction that if attitudes doesn't
change this thread is all for nought.

Best regards
Art

--
73, Cecil http://www.qsl.net/w5dxp

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