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

Yuri, K3BU.us


"Michael Coslo" wrote in message
...
Not that I could fan the flames any more anyhow, but just what was the
original discussion about anyhow?

As in Cecil says what, and those disagreeing with him say what?

I'm curious how something that doesn't seem that complex can generate so
many weeks of acrimony and vitriol! I don't know the answer - but then
again, I'm not really sure what the question is. But I do know where to
look it up....

- 73 de Mike KB3EIA -

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

Yuri,

I know you aren't going to like to hear this, but your article
incorrectly claims the current difference (you call it current drop) is
related to the electrical degrees the coil replaces.
That is not accurate.

ON4UN's book was initially incorrect.

Consider a short vertical antenna. If the current is uniform through
toploading, radiation resistance is higher and current lower throughout
the radiator.

If it is base loaded, current becomes nearly triangular in
distribution. Current into the vertical actually doubles so we have the
same number of ampere-feet. It always requires the same number of
ampere feet to radiate the same power as EM radiation.

The job of the inductor in either system is simply power factor
correction, to bring voltage and current into phase. We have a large
voltage drop across the coil, but current does not change. phase shift
and delay of current through the inductor will also be very small, zero
in a perfect coil.

That is in an ideal antenna with very small stray capacitance to the
outside world compared to the antenna area above the coil.

If we have a physically large coil, the coil MIGHT have significant
capacitance compared to the antenna area above the coil. In this case
there would be a difference in current between the bottom and top
terminal of the coil, and there would be phase difference in the
current entering and leaving the coil, but it is a result of current
being shunted off through displacement currents.

The exact amount would depend on the physical size of the coil and the
capacitance compared to the antenna above the coil.

There is not any magic to any of this, and we don't need to have
standing waves. It is incorrect to consider the coil behavior and
antenna currents by making the coil "act like" it has the missing
electrical dgrees or replaces a section current curve in the antenna.

I can have one antenna and use a good coil design that has essentially
no current difference at each terminal, and replace it with a very
large (or poorly designed) diameter coil that has large differences in
current at each end. Probably the ultimate in poor coil design for base
loading is a linear loading system or stub, while the best would be a
compact coil with nearly equal diameter to length.

The very fact we can change distribution all over the place with only a
change in loading inductor design proves your theory incorrect.

Please try to not extract certain sentences from long explainations to
distort the overall picture of what really happens, and of what I am
describing.

The fact is, we cannot model or predict the behavior of a loading
system without knowing the displacement currents. Neither wave theory
nor "missing antenna length" theory will paint the correct picture of
what is going on, and neither will give an accurate answer to a wide
variety of real world systems.

By the way, this did not start with Belrose and it is not a QST or
Handbook problem. The Antenna Engineering Handbook by Jasik and dozens
of other college or engineering textbooks all deal with the problems
the same way. If you are looking to libel anyone, you need to go all
the way back to James C. Maxwell in the 19th century. It was before the
Civil War that the "big error" you and Barry found started.

I guess it all comes down to if Barry and Yuri are right, or if nearly
every professor, scientist, and engineer from Maxwell to today are
correct. I can measure ANY antenna and prove things behave as I
described. Can you do the same?

73 Tom

wrote:
I know you aren't going to like to hear this, but your article
incorrectly claims the current difference (you call it current drop) is
related to the electrical degrees the coil replaces.
That is not accurate.

The current drop in a wire with standing waves is indeed related
to the number of degrees occupied by the wire. Why shouldn't the
same thing be true for a coil?

Consider a short vertical antenna.

Consider a 1/4WL vertical antenna. The current drop is a function
of the cosine of the number of degrees one moves away from the
source. The same thing is true for a helical antenna. The same
thing is true for a half helical - half wire antenna.

I guess it all comes down to if Barry and Yuri are right, or if nearly
every professor, scientist, and engineer from Maxwell to today are
correct. I can measure ANY antenna and prove things behave as I
described. Can you do the same?

1. You assume the unproven presuppositions of your lumped circuit
model with a religious-like fervor.

2. You make invalid measurements using standing wave current whose
phase contains no phase information. All the phase information is
known to be in the magnitude measurement, but you dismiss any of
the proven arc-cosine calculations as bogus.

With misconceptions and invalid measurements, it is no wonder that
you can prove anything in the world even when it violates the laws
of physics.
--
73, Cecil http://www.qsl.net/w5dxp

Cecil,

Your own calculations would appear to support Tom's assertion.

I believe after a long series of EZNEC models and RRAA messages you came
to the conclusion that the 75 meter bugcatcher coil at 4 MHz had a
traveling wave phase shift of around 10 degrees. I won't get into the
discussion about whether this has any bearing on a standing wave
antenna; let's just assume it does.

This same coil resonated an antenna with a whip length of 10 feet or so.
A quarter wavelength at 4 MHz is around 60 feet. The phase shift that
could be attributed to the whip is therefore around 15 degrees. The
phase shift of the missing 50 feet of wire for a plain quarter wave
antenna would be around 75 degrees.

Is 10 degrees the same amount as 75 degrees? Is this problem stated
incorrectly? Why is Tom wrong?

73,
W4SZ

Cecil Moore wrote:
wrote:

I know you aren't going to like to hear this, but your article
incorrectly claims the current difference (you call it current drop) is
related to the electrical degrees the coil replaces.
That is not accurate.


The current drop in a wire with standing waves is indeed related
to the number of degrees occupied by the wire. Why shouldn't the
same thing be true for a coil?

Gene Fuller wrote:
I believe after a long series of EZNEC models and RRAA messages you came
to the conclusion that the 75 meter bugcatcher coil at 4 MHz had a
traveling wave phase shift of around 10 degrees.

Note that is not a measurement - that is what EZNEC reports but
let's assume, for the sake of discussion, that it is correct. W8JI
measured a 3nS, 4 degree phase shift in a coil twice as long with
43% more inductance. A bigger coil would obviously have a bigger
phase shift because of less current field linkage between the end
coils. So even if the phase shift through the coil is 10 degrees
as reported by EZNEC, W8JI's phase shift measurements were probably
off by *MORE THAN 200%* and that's why Tom is wrong.

This same coil resonated an antenna with a whip length of 10 feet or so.
A quarter wavelength at 4 MHz is around 60 feet. The phase shift that
could be attributed to the whip is therefore around 15 degrees. The
phase shift of the missing 50 feet of wire for a plain quarter wave
antenna would be around 75 degrees.

You are confused. Some time ago, I explained why a mobile antenna
may not be 90 degrees long at all. Did you understand that posting?
All we can say is that (Vfor+Vref)/(Ifor+Iref) is purely resistive.
We don't know how many degrees the reflected wave has traveled in
its round trip because there are too many variables.

So please stop the diversions. I have always said that the delay
through a coil *IS WHAT IT IS* but it is NOT zero and it is not the
3 nS measured by W8JI for that 100 uH coil. It is also not the near-zero
phase shift measured by W7EL using standing wave current phase as the
reference. You, yourself, implied that is an invalid measurement when
you told us there is no phase information in standing wave phase.

Seems to me you are making my argument for me and that your real
argument is with the other side. Have you told W7EL that standing
wave current phase cannot be used to measure the delay through a
coil?
--
73, Cecil http://www.qsl.net/w5dxp

Cecil,

As usual, you evaded the question, but this time you did not even do a
very slick job of evasion.

The question is what happens to the 75 degrees that was formerly
represented by the now-replaced wire. The coil may offer about 10 degrees.

I believe that Tom is stating that 75 is not equal to 10. Sounds like a
reasonable statement to me.

I don't know why you are so worried about the precise details of phase
measurements. Even your standard of precision, +/- 59%, won't make 10
equal to 75.

73,
Gene
W4SZ

Cecil Moore wrote:
Gene Fuller wrote:
I believe after a long series of EZNEC models and RRAA messages you came
to the conclusion that the 75 meter bugcatcher coil at 4 MHz had a
traveling wave phase shift of around 10 degrees.

Note that is not a measurement - that is what EZNEC reports but
let's assume, for the sake of discussion, that it is correct. W8JI
measured a 3nS, 4 degree phase shift in a coil twice as long with
43% more inductance. A bigger coil would obviously have a bigger
phase shift because of less current field linkage between the end
coils. So even if the phase shift through the coil is 10 degrees
as reported by EZNEC, W8JI's phase shift measurements were probably
off by *MORE THAN 200%* and that's why Tom is wrong.

This same coil resonated an antenna with a whip length of 10 feet or so.
A quarter wavelength at 4 MHz is around 60 feet. The phase shift that
could be attributed to the whip is therefore around 15 degrees. The
phase shift of the missing 50 feet of wire for a plain quarter wave
antenna would be around 75 degrees.

You are confused. Some time ago, I explained why a mobile antenna
may not be 90 degrees long at all. Did you understand that posting?
All we can say is that (Vfor+Vref)/(Ifor+Iref) is purely resistive.
We don't know how many degrees the reflected wave has traveled in
its round trip because there are too many variables.

So please stop the diversions. I have always said that the delay
through a coil *IS WHAT IT IS* but it is NOT zero and it is not the
3 nS measured by W8JI for that 100 uH coil. It is also not the near-zero
phase shift measured by W7EL using standing wave current phase as the
reference. You, yourself, implied that is an invalid measurement when
you told us there is no phase information in standing wave phase.

Seems to me you are making my argument for me and that your real
argument is with the other side. Have you told W7EL that standing
wave current phase cannot be used to measure the delay through a
coil?

Gene Fuller wrote:
The question is what happens to the 75 degrees that was formerly
represented by the now-replaced wire. The coil may offer about 10 degrees.

I believe that Tom is stating that 75 is not equal to 10. Sounds like a
reasonable statement to me.

No argument from me. Obviously you didn't understand my previous
explanation that a resonant mobile antenna doesn't have to be 90
degrees long - something I explained weeks ago. Therefore, the coil
doesn't have to be 75 degrees. Please re-read my postings again below
until you understand what I said.

Think of all the possibilities that make (Vfor+Vref)/(Ifor+Iref)
purely resistive without any one of those terms being in phase with
any other of those terms. Then you will realize why that mobile
antenna is probably not 90 degrees long at all.

In my earlier posting, I gave values of phase that make the feedpoint
purely resistive without any one of those terms being in phase with
any other one of those terms.

BOTTOM LINE: Until you can prove that a mobile antenna is 90
degrees long, your argument is just another straw man. What is it
about my following previous statements that you don't understand?

W5DXP wrote:
You are confused. Some time ago, I explained why a mobile antenna
may not be 90 degrees long at all. Did you understand that posting?
All we can say is that (Vfor+Vref)/(Ifor+Iref) is purely resistive.
We don't know how many degrees the reflected wave has traveled in
its round trip because there are too many variables.

So please stop the diversions. I have always said that the delay
through a coil *IS WHAT IT IS* but it is NOT zero and it is not the
3 nS measured by W8JI for that 100 uH coil. It is also not the near-zero
phase shift measured by W7EL using standing wave current phase as the
reference. You, yourself, implied that is an invalid measurement when
you told us there is no phase information in standing wave phase.

Seems to me you are making my argument for me and that your real
argument is with the other side. Have you told W7EL that standing
wave current phase cannot be used to measure the delay through a
coil?
--
73, Cecil http://www.qsl.net/w5dxp

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?

- 73 de Mike KB3EIA -

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

Roy Lewallen wrote:
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.

By now, even you know that standing wave current phase is
fixed and unchanging and that those delay measurements of yours
are invalid whether made on a wire or on a coil.

The loading coil isn't making the antenna act like a physically longer
antenna.

Of course not! The loading coil is making the antenna act
like an electrically longer antenna by adding a phase
shift through the coil. The electrical lengthening is
what resonates the antenna feedpoint to a pure resistance.

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.

Nobody has ever said it affected the antenna's radiation so
that has been and is still just a straw man.

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.

Of course not and nobody has ever said it does. It increases
the electrical length and brings the forward and reflected
waves into phase with each other. That's why the the feedpoint
impedance is resistive.
--
73, Cecil http://www.qsl.net/w5dxp