"Roy Lewallen" wrote in message
...
Mike Coslo wrote:
Yuri Blanarovich wrote:
Check my article that describes the controversy, shows some proof of
reality and then efforts of the "gurus" to deny it and "reason" why
it can't be so. http://www.k3bu.us/loadingcoils.htm The problem is
that back in 1953 in QST article there was erroneous
conclusion/statement made, which propagated through the books, until
W9UCW measured the current across the loading coils and found that
there is significant drop from one end to the other, and the rest is
(ongoing) history

Hmm, certainly it would seem to make sense that:

The current in a typical loading coil in the shortened antennas drops
across the coil roughly corresponding to the segment of the radiator
it replaces.

Quote from your page.

I would not expect anything else. If the loading coil is making the
antenna act like a physically longer antenna, other "qualities" of that
simulation are likely to be similar.

Is there a reason why the coil would *not* do this?

Yes, many, and they've been discussed here at length. That this concept is
wrong can and has been shown by theory, modeling, and measurement. I made
and posted measurements on this newsgroup in November 2003 which
demonstrated clearly that the presumption is false.

The loading coil isn't making the antenna act like a physically longer
antenna. In the extreme case of a physically short inductor at the
feedpoint, it's simply modifying the feedpoint impedance and has no effect
whatever on the antenna's radiation. As the inductor gets longer, it does
become some part of the antenna, but adding an inductor which resonates,
say, a 45 degree physical radiator doesn't make the antenna act like a 90
degree physical radiator.

Roy Lewallen, W7EL

Oooops, carefull here.
As far as I know, nobody has claimed that inserted loading coil replaces the
"missing" degrees of the radiator in terms of providing magical properties
that would look like that "replaced" portion of the antenna, or make the
antenna act like 90 degree full size physical radiator.
What we are saying that the loading coil appears to replace "missing"
electrical degrees of the radiator in order to make it resonant, that is
back to 90 electrical degrees (has to be in order to resonant), which rest
of the existing "straight" radiator forces it to do (+/-). Radiation
properties and efficiency of the loaded antenna is proportional to the area
under the current curve. It is obvious to anyone comparing the area under
the current curve of full size quarter wave radiator vs. loaded radiator
that there is huge difference in area under the curve and performance,
efficiency, which is known and been verified by numerous measurements.
HOW the current curve is modified by different loadings and position along
the radiator is important in knowing how the current distribution curve
along the radiator is modified.
The whole controversy is that "gurus" claim current doesn't drop across the
coil, while we say that it does, therefore making the area under current
curve above the coil smaller and effciency of loaded antenna worse than they
believe and insist on.
Again, when applied in modeling programs, wrong assumption will produce
erroneous results, which will be magnified in multielement antenna designs.
So the "gurus" basically ignore behavior of coil in the standing wave
environment along the loaded radiator, where the current drops from max at
base to zero at the tip, but coil would magicaly resist that, because, bla,
bla, bla.... (see their "reasons")
So while everyone knows (?) that standing wave current drops acros (along)
the wire (all the antenna books show that), but it is "impossible" to drop
along the coiled wire (real inductance - coil, loading stub). Reality and
measurments prove that, but according to them "it can't be so".

I am already gathering necessary hardware to do more experiments,
measurements to show what is really happening, and will prepare articles how
to model and apply it to antenna design.
I would challenge the "unbelievers" to join me and repeat the tests, to see
wasaaaap.

73 Yuri, K3BU

Yuri Blanarovich wrote:
What we are saying that the loading coil appears to replace "missing"
electrical degrees of the radiator in order to make it resonant, ...

W8JI says we are correcting the power factor. Every EE knows that
correcting the power factor involves shifting the phase, i.e.
the coil cannot correct the power factor without providing a phase
shift.

The whole controversy is that "gurus" claim current doesn't drop across the
coil, while we say that it does, ...

That context is specifically inductively loaded mobile antennas
where the current decreases from source to tip of the antenna,
true for all electrical 1/4WL monopoles.

For other antennas, the current may DROP, the current may RISE,
or the current may STAY THE SAME magnitude depending upon where
the coil is installed in the standing wave system. In particular,
none of the "gurus" has even attempted to explain the RISE IN
CURRENT through the coil in the right hand system at:

http://www.qsl.net/w5dxp/test316.GIF

There have been about 10 examples proving the "gurus" wrong and
they simply chose to ignore those examples. They complain that
those examples are biased toward technical correctness. I say,
YES, THEY ARE. AREN'T THEY SUPPOSED TO BE TECHNICALLY CORRECT?
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:
(snip)
W8JI says we are correcting the power factor. Every EE knows that
correcting the power factor involves shifting the phase, i.e.
the coil cannot correct the power factor without providing a phase
shift.

Power factor correction shifts the relative phase of current with
respect to voltage. When talking about a phase shift, you have to be
careful to say what is being shifted relative to what else. There are
lots of possibilities.

A series inductor (a non real, ideal one) with absolutely no phase
shift or magnitude change in the current from one end to the other,
still produces a phase shift of input voltage to output voltage, so
the relative phase of voltage to current at the input is different
compared to the relative phase of voltage to current at the output. I
think this is the power factor correction effect W8JI is referring to.

Any real inductor does this, and also does some other things.

John Popelish wrote:
A series inductor (a non real, ideal one) with absolutely no phase shift
or magnitude change in the current from one end to the other, still
produces a phase shift of input voltage to output voltage, ...

If the voltage is leading the current, and the current
experiences no phase shift through the coil, doesn't that
imply that the voltage must travel faster than light and
indeed jump forward in time to catch up with the phase
of the current?

What does it mean to the E-fields and H-fields to say
the voltage is leading the current?
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:
John Popelish wrote:

A series inductor (a non real, ideal one) with absolutely no phase
shift or magnitude change in the current from one end to the other,
still produces a phase shift of input voltage to output voltage, ...


If the voltage is leading the current, and the current
experiences no phase shift through the coil, doesn't that
imply that the voltage must travel faster than light and
indeed jump forward in time to catch up with the phase
of the current?

What does it mean to the E-fields and H-fields to say
the voltage is leading the current?

It means that the current at both ends of the coil was delayed
(relative to its phase if the coil had not been there). It means that
there was a voltage difference across the ends of the coil that drove
that current through the coil.

John Popelish wrote:

Cecil Moore wrote:
What does it mean to the E-fields and H-fields to say
the voltage is leading the current?

It means that the current at both ends of the coil was delayed (relative
to its phase if the coil had not been there). It means that there was a
voltage difference across the ends of the coil that drove that current
through the coil.

In order to avoid any delay through the coil, you propose a delay
in the one inch of wire at the bottom of the coil? Does that really
make sense to you? How is this magic delay accomplished?
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:
John Popelish wrote:

Cecil Moore wrote:

What does it mean to the E-fields and H-fields to say
the voltage is leading the current?


It means that the current at both ends of the coil was delayed
(relative to its phase if the coil had not been there). It means that
there was a voltage difference across the ends of the coil that drove
that current through the coil.


In order to avoid any delay through the coil, you propose a delay
in the one inch of wire at the bottom of the coil? Does that really
make sense to you? How is this magic delay accomplished?

Exactly the way it is accomplished if you apply AC to an LC "L" low
pass filter that droves a resistor load. The short antenna acts as
the capacitor (in parallel with losses and radiation) in the circuit.
It is resonated with the series inductor so both the inductance and
capacitance cancel, so the source drives only the losses and
radiation. Power factor corrected.

If you don't believe me, simulate it with EZNEC. Connect a source to
a parallel combination of C and R. Record the phase of the current
with respect to the voltage (the current will lead). Then add a
series inductance that cancels the capacitance, and the current will
be delayed till it matches the phase of the applied voltage. Power
factor corrected.

Cecil Moore wrote:
Yuri Blanarovich wrote:
What we are saying that the loading coil appears to replace "missing"
electrical degrees of the radiator in order to make it resonant, ...

W8JI says we are correcting the power factor. Every EE knows that
correcting the power factor involves shifting the phase, i.e.
the coil cannot correct the power factor without providing a phase
shift.

This is another area where you fall right square on your face.

An inductance changes the relationship between phase of voltage and
current, NOT current through the inductance from terminal to terminal.

You either know that and are intentionally avoiding it to save face, or
you need to brush up on basic theory.

The whole controversy is that "gurus" claim current doesn't drop across the
coil, while we say that it does, ...

Yuri again distorts fact. What everyone is saying is there can be a
current change, but it is not caused by standing waves or missing
antenna area. It is caused by displacement current, and so can have a
wide range of change in a given antenna.

Please write that down Yuri, and keep it in front of you so you don't
forget again!

73 Tom

wrote:
An inductance changes the relationship between phase of voltage and
current, NOT current through the inductance from terminal to terminal.

That's true only for a lumped inductance which doesn't exist
in reality.

Yuri again distorts fact. What everyone is saying is there can be a
current change, but it is not caused by standing waves or missing
antenna area. It is caused by displacement current, and so can have a
wide range of change in a given antenna.

In the graphic at: http://www.qsl.net/w5dxp/test316.GIF
in the right hand configuration the current at the bottom
of the coil is 1.3 amps and the current at the top of the
coil is 2.1 amps.

Your explaination for more current at the top of the coil
than at the bottom is that 0.8 amps of displacement current
is jumping up from earth ground into the side of the coil
and flowing out the top?

Would you please describe that bit of magic in a little more
detail?
--
73, Cecil http://www.qsl.net/w5dxp

Yuri Blanarovich wrote:

Oooops, carefull here.
As far as I know, nobody has claimed that inserted loading coil replaces the
"missing" degrees of the radiator in terms of providing magical properties
that would look like that "replaced" portion of the antenna, or make the
antenna act like 90 degree full size physical radiator.

Agreed, it's not quite stated as such. Here are some statements which
were made:

From your web page http://www.k3bu.us/loadingcoils.htm, in bold type:

"In summary:
The current in a typical loading coil in the shortened antennas drops
across the coil roughly corresponding to the segment of the radiator it
replaces."

By Cecil, on March 5, on this newsgroup:

"A loading coil thread is climaxing over on qrz.com. I have
used EZNEC to generate a graphic which shows a 3/4WL vertical
and a similar 1/2WL vertical with a ~1/4WL loading coil. The
loading coil is a wire helical coil containing (surprise)
roughly 1/4WL of wire. The coil does a good (not perfect)
job of replacing 1/4WL of wire. Many things can be gathered
from observation of the current reported by EZNEC for the
two antennas. The coil occupies roughly the same number
of degrees of the antenna as the wire it replaces. The
current at the top and bottom of the coil is roughly the
same as the current at the two ends of the wire it replaces.
Is the coil an exact replacement? Of course not."

What we are saying that the loading coil appears to replace "missing"
electrical degrees of the radiator in order to make it resonant, that is
back to 90 electrical degrees (has to be in order to resonant), which rest
of the existing "straight" radiator forces it to do (+/-).

It's getting muddier and muddier just what you mean by "replace". Nobody
has questioned that a loading coil makes the antenna resonant; that's
its purpose. But that's simply an impedance transformation property
which can be accomplished well away from the antenna by many different
methods.

Radiation
properties and efficiency of the loaded antenna is proportional to the area
under the current curve. It is obvious to anyone comparing the area under
the current curve of full size quarter wave radiator vs. loaded radiator
that there is huge difference in area under the curve and performance,
efficiency, which is known and been verified by numerous measurements.
HOW the current curve is modified by different loadings and position along
the radiator is important in knowing how the current distribution curve
along the radiator is modified.

I agree with all this. I'm glad you've clarified this for the benefit of
posters like the one to whom my recent posting was directed.

The whole controversy is that "gurus" claim current doesn't drop across the
coil, while we say that it does, therefore making the area under current
curve above the coil smaller and effciency of loaded antenna worse than they
believe and insist on.

I don't think you'll have any trouble winning your arguments against
your imaginary "gurus", whomever and whatever they might be. Over two
years ago I made careful measurements which showed a current difference
between the top and bottom of a loading coil. Cecil posted an EZNEC
model on his web site showing a substantial difference. I've commented
on it several times, explaining the reason for the difference, and
modifying the model to illustrate the explanation.

The controversy is in the explanation of the difference. It simply
doesn't require Cecil's theories. I've never been able to tell exactly
what your theory is, if you indeed have one.

Again, when applied in modeling programs, wrong assumption will produce
erroneous results, which will be magnified in multielement antenna designs.
So the "gurus" basically ignore behavior of coil in the standing wave
environment along the loaded radiator, where the current drops from max at
base to zero at the tip, but coil would magicaly resist that, because, bla,
bla, bla.... (see their "reasons")

Would you name these "gurus" so we can read their postings and see what
you're talking about?

So while everyone knows (?) that standing wave current drops acros (along)
the wire (all the antenna books show that), but it is "impossible" to drop
along the coiled wire (real inductance - coil, loading stub). Reality and
measurments prove that, but according to them "it can't be so".

I am already gathering necessary hardware to do more experiments,
measurements to show what is really happening, and will prepare articles how
to model and apply it to antenna design.
I would challenge the "unbelievers" to join me and repeat the tests, to see
wasaaaap.

You'll be surprised when everyone agrees that there's a current
difference between the top and bottom of the coil. Unless your "gurus"
show up, whomever they are.

I've already made a test and posted the results, over a year ago. When
it failed to show a current difference anywhere near the number of
degrees it "replaced", your complaint was that I was using an inductor
which was too small physically. So obviously your theory works only on
certain size inductors. Once you or Cecil has the theory fully worked
out, it should be able to not only tell us what the current difference
between top and bottom should be, but also how physically large an
inductor must be before the theory works. And why it doesn't work for
physically small inductors.

Those of us stuck with old fashioned conventional theory can explain the
drop for small as well as large coils, so you folks have a bit of
catching up to do.

I think a lot of the experimental work can be done by modeling. I'd be
interested in hearing of any cases where measured results differ
significantly from EZNEC results. Incidentally, your web page is a bit
outdated in that respect, apparently being written before EZNEC v. 4.0
was available with its automated helix creation feature.

Roy Lewallen, W7EL