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-   -   W8JI "shines" at Hamvention (https://www.radiobanter.com/antenna/1757-w8ji-%22shines%22-hamvention.html)

Yuri Blanarovich May 18th 04 03:01 AM

W8JI "shines" at Hamvention
 
I was "privileged" to be a witness to more "wisdom" from the antenna "guru"
W8JI at the Dayton Hamvention Antenna forum.
Based on his "unshakable" knowledge that current in the antenna loading coil is
constant, he proclaimed that it doesn't matter where the loading coil in the
antenna is, on the bottom, middle or close to the top.

Yuri



* May 18th 04 04:12 AM

Does make a big difference, no current at the top!
The wire ends there, so current must stop.
Most current typically near the bottom, and feed, but can be higher up
depending upon bands.
Perhaps he is addressing the degenerate cases of antenna very long, and
antenna too short?

"Yuri Blanarovich" wrote in message
...
I was "privileged" to be a witness to more "wisdom" from the antenna

"guru"
W8JI at the Dayton Hamvention Antenna forum.
Based on his "unshakable" knowledge that current in the antenna loading

coil is
constant, he proclaimed that it doesn't matter where the loading coil in

the
antenna is, on the bottom, middle or close to the top.

Yuri





Mark Keith May 18th 04 11:13 AM

oUsama (Yuri Blanarovich) wrote in message ...
I was "privileged" to be a witness to more "wisdom" from the antenna "guru"
W8JI at the Dayton Hamvention Antenna forum.
Based on his "unshakable" knowledge that current in the antenna loading coil is
constant, he proclaimed that it doesn't matter where the loading coil in the
antenna is, on the bottom, middle or close to the top.

Yuri


I bet that includes a large capacity hat though. If he is using a
large hat, what he says is true. If he is not using a hat, it is not
true. And I'm sure he knows that. Any current taper through the coil
in itself, has little bearing on the best location of the coil and
performance. Taper, or no taper, it's location will greatly effect
efficiency when NO hat is used. No doubt about it. But, if you are
using a large hat, what he says is fairly true. The location of the
coil really doesn't matter near as much, because the current
distribution is fairly linear even with the coil at the base, middle
or top. There might be slight improvements by raising the coil on a
large hatted system, but it will be minor compared to the no-hat
version. MK

Cecil Moore May 18th 04 07:47 PM

Yuri Blanarovich wrote:
Based on his "unshakable" knowledge that current in the antenna loading coil is
constant, ...


Strange, every measured experiment he himself conducted on real-world
air-core coils proved that the current at each end of the coil is NOT
constant.

Did he say if one puts the loading coil at the top of the antenna,
with no stinger, currents at the top of the coil and bottom of the
coil are equal?

When will otherwise rational engineers stop trying to use circuit
model math on distributed network problems? The current in a standing-
wave antenna wire is NOT constant, varies inch by inch, and that's a
*straight* piece of wire. So if we use more wire coiled up, the current
then becomes constant magnitude/phase and instantaneous? (faster than
light?) To speed up computer buses all we have to do is install coils
in series?

Did you notice W8JI changed his web page? The once outrageous statements
have been considerably modified.
--
73, Cecil http://www.qsl.net/w5dxp



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Jim Kelley May 18th 04 09:09 PM

Cecil Moore wrote:
The current in a standing-
wave antenna wire is NOT constant, varies inch by inch, and that's a
*straight* piece of wire.


Or more precisely, the amplitude of the mathematical superposition of
forward and reverse traveling wave currents in a half-wave dipole
antenna varies inch by inch.
It is the EM fields produced by the traveling wave currents that in fact
superpose. That superposition results in a net field which is identical
to the field which would be produced if a 'standing wave current' could
in fact radiate.

Did you notice W8JI changed his web page? The once outrageous statements
have been considerably modified.


I've noticed fewer of them on your web page as well, Cecil. Perhaps the
world is coming to equilibrium. :-)

73, Jim AC6XG

Mike Coslo May 18th 04 09:39 PM

Cecil Moore wrote:
Yuri Blanarovich wrote:

Based on his "unshakable" knowledge that current in the antenna
loading coil is
constant, ...



Strange, every measured experiment he himself conducted on real-world
air-core coils proved that the current at each end of the coil is NOT
constant.

Did he say if one puts the loading coil at the top of the antenna,
with no stinger, currents at the top of the coil and bottom of the
coil are equal?

When will otherwise rational engineers stop trying to use circuit
model math on distributed network problems? The current in a standing-
wave antenna wire is NOT constant, varies inch by inch, and that's a
*straight* piece of wire. So if we use more wire coiled up, the current
then becomes constant magnitude/phase and instantaneous?


I'm worried - even I understand that!


- Mike KB3EIA -


Cecil Moore May 18th 04 10:16 PM

Jim Kelley wrote:

Cecil Moore wrote:
The current in a standing-
wave antenna wire is NOT constant, varies inch by inch, and that's a
*straight* piece of wire.


Or more precisely, the amplitude of the mathematical superposition of
forward and reverse traveling wave currents in a half-wave dipole
antenna varies inch by inch.
It is the EM fields produced by the traveling wave currents that in fact
superpose.


Of course, I was referring to *net* current which is a superposition
of forward and reflected currents, or H-fields if you prefer. The bottom
line is that if magnitude and phase vary inch by inch in a straight piece
of wire used in a standing-wave antenna, are we to believe that the variation
can be reduced by adding more wire, just in a spiral?

Did you notice W8JI changed his web page? The once outrageous statements
have been considerably modified.


I've noticed fewer of them on your web page as well, Cecil. Perhaps the
world is coming to equilibrium. :-)


My web page problem is the definition of the reflection coefficient.
RHO and S11 have different definitions. Stand by for an explanation that
even you can understand. :-)
--
73, Cecil http://www.qsl.net/w5dxp



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Jim Kelley May 18th 04 10:35 PM

Cecil Moore wrote:
Of course, I was referring to *net* current which is a superposition
of forward and reflected currents, or H-fields if you prefer.


And with H you get E to boot!

My web page problem is the definition of the reflection coefficient.


Great. I'm interested to read it.

RHO and S11 have different definitions.


Do you remember when you and I talked about that?

Stand by for an explanation that
even you can understand. :-)


That's the best kind! :-)

73, Jim AC6XG

Yuri Blanarovich May 19th 04 02:07 AM


Did he say if one puts the loading coil at the top of the antenna,
with no stinger, currents at the top of the coil and bottom of the
coil are equal?


Not specifically.

When will otherwise rational engineers stop trying to use circuit
model math on distributed network problems? The current in a standing-
wave antenna wire is NOT constant, varies inch by inch, and that's a
*straight* piece of wire. So if we use more wire coiled up, the current
then becomes constant magnitude/phase and instantaneous? (faster than
light?) To speed up computer buses all we have to do is install coils
in series?


When they can read their diplomas, maybe? :-)

Did you notice W8JI changed his web page? The once outrageous statements
have been considerably modified.
--
73, Cecil http://www.qsl.net/w5dxp


No, but I will have a look. I have saved the "before" pages, so it will be
interesting to compare. This would be typical of him. First ho goes quiet for a
while, then he changes his beliefs, then he emerges as a guru, teaching the
stupid about the virtues of his "inventions" (stolen, plagiarized from others.)

When I brought this to attention of K3LR, antenna forum moderator, he countered
with "he wins contests and works DX"
and N6BV: "he is right". So I was grounded and dummyfounded :-)

Now that snow melted and I got my Radiomobile's brake lines fixed, I should do
the experiments and get some real data and do that article. Just that I got
sucked to another project, designing "Dream Radio" that I am more excited,
especially after seeing pieces of (radio) furniture by the JA biggies.

I am sorry I missed W7EL booth, would have loved to say HI in person. Just
gotta order the upgrade to EZNEC, I can use the new insulated wire modeling
feature.

73 Yuri, www.K3BU.us
www.computeradio.us home of Dream Radio One


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