"John Smith" wrote
I don't believe any of the modeling programs are "aware" of what dynamics
are causing the DLM to outperform expected/modeled results--
__________

Using Vincent's own numbers for the performance of a 3.5 MHz standard DLM
shows otherwise, and that doesn't necessarily take a modeling program to
discover.

As I stated in my last post in this thread, I was NOT using NEC to model the
DLM in any form. I modeled a standard, base loaded monopole of the same
physical height as the 3.5 MHz DLM, and compared the NEC result for that to
the DLM data in the URI test report, and the DLM data to the well-known
performance of a standard 1/4-wave monopole -- which performance has been
accurately measured.by broadcast stations thousands of times over the last
70+ years.

That DLM system radiated only about 59% of the power applied to it, which is
well below the ~95% radiated by a standard 1/4-wave monopole using a
"broadcast type" buried radial ground.

Check the numbers for yourself.

RF

John Smith wrote:
1/2 wave monopoles
have little dependence of a full counterpoise or ground for, at least,
acceptable performance.

The Zepp antenna is a 1/2WL monopole with no
counterpoise.
--
73, Cecil http://www.w5dxp.com

On 27 Nov, 06:18, Cecil Moore wrote:
John Smith wrote:
1/2 wave monopoles
have little dependence of a full counterpoise or ground for, at least,
acceptable performance.

The Zepp antenna is a 1/2WL monopole with no
counterpoise.
--
73, Cecil http://www.w5dxp.com

That makes sense. Physically it is half wave
but electrically it is a full wave antenna.
It is able to radiate on its surface and is unable to radiate
as it returns down the center of the wire.
(assuming the antenna is not tubular)
The path on the outside is helical which promotes a slow wave
so the physical wavelength has to be increased slightly to
compensate.When JS made his Vincent model the physical
length was slightly longer than a electrical half wave length
because of this so it still was not quite balanced.
To bring the antenna into balance there must be a contrawound
widing put into place such that the radiating current on the
return path is exposed and not enclosed. Doing this will not
correct the slow wave phenomina but will neutralise the
increased inductance created by the windings and at the same time
bring the radiator back to equilibrium where the correct LC ratio
is maintained and the radiator is a full electrical wavelength in
equilibrium and of variable shape and elevation.
Sound familiar?
Art Unwin.....KB9MZ...xg
Note the wire center contains no inductive or capacitive
properties, only resistive. Thus radiation will be slightly
over 50% of a full wave radiator.

"Cecil Moore"
The Zepp antenna is a 1/2WL monopole with no
counterpoise.
______________

Here are some comments by W8JI about the need for some kind of r-f ground or
counterpoise on Zepps and other end-fed ham antennas.

http://www.w8ji.com/end-fed_vertical...ontal_zepp.htm

RF

On Tue, 27 Nov 2007 09:53:16 -0500, "Jimmie D"
wrote:

Is there enough data to calculate the performance of the DLM antenna if it
were installed at a typical AM broadcast facility

Hi Jimmie,

Yes.

instead of at the naval
test site?

That's the point, the difference does not recover the DLM lost power
as there is no difference (and in fact, the Navy site probably
exhibits the DLM's best numbers, which do not rise to that of
conventional antennas).

The same has been demonstrated by the engineering report of the eh
antenna. In that situation too, the "inventors" didn't have the math
skills of a 4th grader to compare numbers exhibiting their poorer
showing in comparison to a low end performing commercial antenna.

73's
Richard Clark, KB7QHC

Richard Fry wrote:

...
That DLM system radiated only about 59% of the power applied to it,
which is well below the ~95% radiated by a standard 1/4-wave monopole
using a "broadcast type" buried radial ground.

Check the numbers for yourself.

RF

Richard:

I built a few ...

One is on my sportster for 20m. Model on, I am using it!

Find me a better/ultra-light 1/2 wave mobile antenna which will mount to
my modified/snap-on fiberglass touring case--using my bike frame as a
counterpoise and still make it under trees/overpasses and I'll consider it!

This discussion, while interesting, is only an exercise in futility;
however, I understand the controversy surrounding this particular
antenna ... you are not the first, you won't be the last.

I just bought a new (2007) Buick Lacrosse, I suspect the Vincent antenna
is already buried in the wheels transmitting the tire pressure data to
the cars computer (I know the patent rights have already been purchased
for such.)

I am a humble software engineer with an interest in amateur radio and
learning more--if I were others, I'd investigate it for myself ... the
darn antenna is so easy to construct and play with.

Regards,
JS

On Tue, 27 Nov 2007 07:31:55 -0800 (PST), art
wrote:

It is able to radiate on its surface and is unable to radiate
as it returns down the center of the wire.
(assuming the antenna is not tubular)

Hi Arthur,

Very interesting assumption. I suppose (and that is always a risk
with a renowned theoretician such as yourself) that you have an
instrument that can detect the difference in radiation between a solid
wire and a tubular one - all other externalities being the same?

No, I suppose not. You've been burnt too many times with your own
results confounding your expectations. However, putting that grief
aside (and it must be a terrible burden to endure), if a hollow
element were filled with a custard center so that it was in
equilibrium, would it radiate?

73's
Richard Clark, KB7QHC

John Smith wrote:


I just bought a new (2007) Buick Lacrosse, I suspect the Vincent antenna
is already buried in the wheels transmitting the tire pressure data to
the cars computer (I know the patent rights have already been purchased
for such.)


Perhaps not.

The press release from URI at the end of August 2007 says, in part:


"First, the U.S. Patent Office awarded him a patent for his system and
method for providing a distributed loaded monopole antenna with all 29
of its claims (or applications) earlier this year. The patent is pending
in several foreign countries.

Then the Lear Corporation, ranked 130 among Fortune 500 companies,
licensed six of those applications, which are now in development. Lear
is one of the world’s largest suppliers of automotive interior systems
and components."


Since auto companies take years to add anything new, it seem unlikely
that your Buick is already blessed with a Vincent/Lear DLM.


I wonder which 6 claims were licensed by Lear? Of the 29 claims, there
are 4 independent claims, 1, 18, 21, and 24, with the remainder
dependent claims. It seems unlikely that anyone would license random
dependent claims, so it would appear that 18, 21, and/or 24 would be the
most likely candidates.

73,
Gene
W4SZ

On 27 Nov, 08:54, Richard Clark wrote:
On Tue, 27 Nov 2007 07:31:55 -0800 (PST), art
wrote:

It is able to radiate on its surface and is unable to radiate
as it returns down the center of the wire.
(assuming the antenna is not tubular)

Hi Arthur,

Very interesting assumption. I suppose (and that is always a risk
with a renowned theoretician such as yourself) that you have an
instrument that can detect the difference in radiation between a solid
wire and a tubular one - all other externalities being the same?

No, I suppose not. You've been burnt too many times with your own
results confounding your expectations. However, putting that grief
aside (and it must be a terrible burden to endure), if a hollow
element were filled with a custard center so that it was in
equilibrium, would it radiate?

73's
Richard Clark, KB7QHC

The material is diamagnetic which means that it has the ability to
levitate particles of like form. Levitation is the result of a
particle
escaping from its immediate gravitational pull and where it can exist
unharmed by surrounding gravitational action which by its very nature
has voids in gravitational action. In the case of a Gaussian
field that means to escape to beyond the arbitary border.
It is this very movement of particles without regard to gravitational
forces that allows for straight line actions inspite of the spherical
surface of the earth
Where material is solid then the internal surfaces of the skin depth
which is also the external surface of current flow cannot levitate any
part of the intervening structure.
Levitation is created by a magnetic field where escape from the parent
structure is possible.On the inside levitation since particles
concerned
are part and parcel of the material without freedom levitation is not
possible.
By the same token inductance and capacitance cannot exist on the
internal
path since another skin depth cannot exist.

If a radiator is made of a tube of minimal thickness with respect to
skin
depth and the ends filled with the same diamagnetic
material where a fuse connects them, the fuse will blow when RF is
applied to the external surface

On Tue, 27 Nov 2007 10:32:46 -0800 (PST), art
wrote:

On 27 Nov, 08:54, Richard Clark wrote:
On Tue, 27 Nov 2007 07:31:55 -0800 (PST), art
wrote:

It is able to radiate on its surface and is unable to radiate
as it returns down the center of the wire.
(assuming the antenna is not tubular)
....
you have an
instrument that can detect the difference in radiation between a solid
wire and a tubular one - all other externalities being the same?
....
If a radiator is made of a tube of minimal thickness with respect to
skin
depth and the ends filled with the same diamagnetic
material where a fuse connects them, the fuse will blow when RF is
applied to the external surface

Hi Arthur,

Let's make this practical for 2M. The skin depth there is all of 30
millionths of an inch and we can talk about a tube with maybe 100
millionths of an inch wall thickness, so let's make it a tube with a 1
thousandth inch diameter with the conventional length of 39 inches.

What size fuse will blow?

73's
Richard Clark, KB7QHC