Vincent antenna
 

The above antenna does not have a ground plain such that it is
unbalanced.
If the feed line was buried underground for a distance at least a half
wave long
would the external current on the feed braid leak to earth/ground
where the transmitter
itself would see no interference from the imbalance? A test for this
I suppose is
rubbing your hand over the coax at the transmitter site to see if any
swr variation occur
Art

Vincent antenna
 

"art" wrote
The above antenna does not have a ground plain
such that it is unbalanced.
_______________

The DLM antenna is a monopole (DLM stands for distributed loaded monopole).
All practical vertical monopoles require an r-f ground or counterpoise of
some kind.

You might want to contact Robert Vincent to confirm for yourself that this
true for the DLM.

And If it didn't, why would he bother to test it at a site with a
near-perfect, salt water ground system?

RF

Vincent antenna
 

On 26 Nov, 07:32, "Richard Fry" wrote:
"art" wrote The above antenna does not have a ground plain
such that it is unbalanced.

_______________

The DLM antenna is a monopole (DLM stands for distributed loaded monopole).
All practical vertical monopoles require an r-f ground or counterpoise of
some kind.

You might want to contact Robert Vincent to confirm for yourself that this
true for the DLM.

And If it didn't, why would he bother to test it at a site with a
near-perfect, salt water ground system?

RF

That's what I said

Vincent antenna
 

Richard Fry wrote:

...
And If it didn't, why would he bother to test it at a site with a
near-perfect, salt water ground system?

RF

Because most antennas are measured against a chosen "standard" antenna
which was/is tested over a perfect/near-perfect ground--I'd imagine ...
(today, the "test standard" is likely to be an antenna modeled by
computer software--however, usually it is modeled over a virtual perfect
ground ...)

But then, your standard may be/have-been some bent coat-hanger
established over the poorest ground you could find in the world?

However, you already knew this ... well, most did.

Regards,
JS

Vincent antenna
 

John Smith wrote:
But then, your standard may be/have-been some bent coat-hanger

Hey, a new reference standard, dBch
--
73, Cecil http://www.w5dxp.com

Vincent antenna
 

Cecil Moore wrote:
John Smith wrote:
But then, your standard may be/have-been some bent coat-hanger

Hey, a new reference standard, dBch

Cecil:

I woke up with a bit of back pain--didn't help the mood here ... that's
changing. chuckle

Regards,
JS

Vincent antenna
 

"John Smith" wrote
Because most antennas are measured against a chosen "standard"
antenna which was/is tested over a perfect/near-perfect ground.

And you're thinking that the Vincent DLM was not using the same
r-f ground used by the "standard" antenna?

But then, your standard may be/have-been some bent coat-hanger established
over the poorest ground you could find in the world?

That would benefit Mr. Vincent, not me.

I have used NEC to model a conventional monopole of the same height as the
standard 3.5 MHz DLM in the URI test report. Using an extremely good r-f
ground (0.5 ohms) and 1.5 ohms of matching loss to the monopole produced a
groundwave field of about 238 mV/m for 1 kW at 1 km. A perfect reference
monopole over a perfect ground plane would produce about 313 mV/m for 1 kW
at 1 km.

This field ratio is about the same as given in the URI report for the
standard 3.5 MHz DLM versus the Navy's standard (1/4-wave) monopole, and
relates to an antenna system radiation efficiency for that DLM of about 59%.

Note that this does not come especially close to the claim made for the DLM
as being the near-equivalent of a good 1/4-wave monopole.

RF

Vincent antenna
 

Richard Fry wrote:

...
Note that this does not come especially close to the claim made for the
DLM as being the near-equivalent of a good 1/4-wave monopole.

RF

The original question centered around why Mr. Vincent would test a 1/2
DLM over perfect/near-perfect ground when a 1/2 wave monopole only
requires a very minimal ground (indeed, I have seen 1/2 ants. on boats
with NO counterpoise--well, the outer braid of the coax choked off a 1/4
wave down.)

He chose perfect ground because the standard is, at least, usually
tested over perfect/near-perfect ... I'd imagine.

Regards,
JS

Vincent antenna
 

"John Smith" wrote
The original question centered around why Mr. Vincent would test a 1/2 DLM
...

What is a 1/2 DLM?

Half-wave dipoles don't require good r-f grounds to radiate well. They are
balanced radiators. All monopoles (including the DLM) do, however.

RF

Vincent antenna
 

Richard Fry wrote:
"John Smith" wrote
The original question centered around why Mr. Vincent would test a 1/2
DLM ...

What is a 1/2 DLM?

Half-wave dipoles don't require good r-f grounds to radiate well. They
are
balanced radiators. All monopoles (including the DLM) do, however.

RF

A half wave DLM is one which consists of a 1/2 wavelength radiator ...
google it; or, Vincents patent contains VERY complete data on the
construction of one--he tested it, also, at the Navy complex.

I thought this was the one Arts' original post addressed ...

Regards,
JS

Vincent antenna
 

John Smith wrote:

A half wave DLM is one which consists of a 1/2 wavelength radiator ...
...

Change the above:

A half wave DLM is one which consists of a 1/2 ELECTRICAL wavelength
radiator ...

Regards,
JS

Vincent antenna
 

"John Smith" wrote
A half wave DLM is one which consists of a 1/2 wavelength radiator ...
google it; or, Vincents patent contains VERY complete data on the
construction of one--he tested it, also, at the Navy complex.
later...
A half wave DLM is one which consists of a 1/2 ELECTRICAL wavelength
radiator ...
________

I just looked at that patent, and saw nothing about that. I did see many
references to the need for a good r-f ground for the DLM.

As a variation, the patent describes putting two DLMs back to back to create
a dipole. Of course, that form is no longer a DLM, it is a loaded dipole.

Can you refer me to the page(s) of that patent that describe(s) what you are
writing about?

RF

Vincent antenna
 

Richard Fry wrote:

...
I just looked at that patent, and saw nothing about that. I did see
many references to the need for a good r-f ground for the DLM.

As a variation, the patent describes putting two DLMs back to back to
create a dipole. Of course, that form is no longer a DLM, it is a
loaded dipole.

Can you refer me to the page(s) of that patent that describe(s) what you
are writing about?

RF

Well, give me a bit, and remind me if I don't get back to you in a
couple of days ...

However, I have a 10m and a 20m 1/2-wave DLM I am using now, I
constructed them from the info. gleamed from the patent, conversation
with Vincent, web, ...

Hold on ... just overloaded after the holidays--except for quick
comments ...

Regards,
JS

Vincent antenna
 

On 26 Nov, 10:46, John Smith wrote:
Richard Fry wrote:

...

I just looked at that patent, and saw nothing about that. I did see
many references to the need for a good r-f ground for the DLM.

As a variation, the patent describes putting two DLMs back to back to
create a dipole. Of course, that form is no longer a DLM, it is a
loaded dipole.

Can you refer me to the page(s) of that patent that describe(s) what you
are writing about?

RF

Well, give me a bit, and remind me if I don't get back to you in a
couple of days ...

However, I have a 10m and a 20m 1/2-wave DLM I am using now, I
constructed them from the info. gleamed from the patent, conversation
with Vincent, web, ...

Hold on ... just overloaded after the holidays--except for quick
comments ...

Regards,
JS

The post that originated this thread stated that the antenna was
unbalanced and therefore should have a ground system.
Fry had some comments that were not related or in conflict
with what was stated, he just doesn't read to well.
Back to the originating post.The antenna is unbalanced but without a
connected ground system such that current will flow on the outside of
the coax braid. If this braid is buried this current will leak to the
ground(capacitive coupling). Question. At what distance does the coax
have to travel such that current on the outside does not exist?
Art

Vincent antenna
 

art wrote:

...
The post that originated this thread stated that the antenna was
unbalanced and therefore should have a ground system.
Fry had some comments that were not related or in conflict
with what was stated, he just doesn't read to well.
Back to the originating post.The antenna is unbalanced but without a
connected ground system such that current will flow on the outside of
the coax braid. If this braid is buried this current will leak to the
ground(capacitive coupling). Question. At what distance does the coax
have to travel such that current on the outside does not exist?
Art

I understand this Art. However, I am sure you won't mind a bit of side
conversation--don't mean to hijack your thread. ;-)

Regards,
JS

Vincent antenna
 

On Mon, 26 Nov 2007 11:06:29 -0800 (PST), art
wrote:

At what distance does the coax
have to travel such that current on the outside does not exist?

Hi Arthur,

According to Brown, Lewis, and Epstein's work, the currents absorbed
by ground dissipate radial wire current (what is flowing on the
exterior of a coax) in a very short interval.

However, just where it "does not exist" is like the problem you have
with skin effect. The current diminishes asymptotically towards zero,
but most would agree that the practical current is gone within less
than a quarter wave length. The convergence with the asymptote could
be described to be infinitely far away - especially when the current
levels induced in far receiver antennas is so miniscule in comparison
to the diminished radial currents (4,5 or 6 orders of magnitude?).

73's
Richard Clark, KB7QHC

Vincent antenna
 

Richard Fry wrote:

...
Can you refer me to the page(s) of that patent that describe(s) what you
are writing about?

RF

OK. Just quickly, so you don't think I am just attempting to "dust you
off."

This:

"Current profiles have been developed for various such embodiments of
1/2 wave and 5/8 wave distributed loaded monopole antennas. The
manipulation of helix length and inductance as well as the ratio of load
coil to helix inductance may achieve a wide variety of suitable antennas."

From he (beware line wrapping--it is a LONG URL!)

http://patft.uspto.gov/netacgi/nph-P...m+AND+monopole

Further, you know, Mr. Vincent is one nice guy, at least my
communications with him convinced me of such. He offered to send me a
CD with all pertinent data on it (one ham to another.)

I would encourage you to make direct contact with him, if the naysayers
haven't totally peeved him off, I'd venture to guess it would be quite
an enlightening and enjoyable interchange ...

Unfortunately, I don't remember how I got his email and didn't add it to
my address book, probably got it from somewhere on the universities site
.... this might be a place to start (and has a contact phone number--if
nothing else.) But, I am sure a search/email-inquiry to uri.edu would
bear fruit.

http://www.uri.edu/news/vincent/report05/


Regards,
JS

Vincent antenna
 

"art" wrote
The antenna is unbalanced but without a connected
ground system such that current will flow on the
outside of the coax braid.
______________

Following in its odd style is one of the many references in the DLM patent
to the need/use of a "connected ground system" for it.

QUOTE In this embodiment the antenna is shown grounded to earth through a
grounding rod, ground wire and connected to the base of the antenna and
electrically connected using a ground clamp. Radial wires extending above
ground or buried in the ground are electrically connected to the antenna
using the ground wire and the ground rod and extend from the antenna base
for a uniform distance but not limited to any specific length. END QUOTE.

So another one of your cherished beliefs is shown to be untrue.

RF

Vincent antenna
 

"John Smith" wrote
OK. Just quickly, so you don't think I am just attempting to "dust you
off." This:
"Current profiles have been developed for various such embodiments of 1/2
wave and 5/8 wave distributed loaded monopole antennas. The manipulation
of helix length and inductance as well as the ratio of load coil to helix
inductance may achieve a wide variety of suitable antennas."

Thanks, but a monopole of every electrical length is still a monopole, and
they ALL require a very good r-f ground or counterpoise for best
perfromance.

Further, you know, Mr. Vincent is one nice guy, at least my communications
with him convinced me of such. I would encourage you to make direct
contact with him, if the naysayers haven't totally peeved him off, I'd
venture to guess it would be quite an enlightening and enjoyable
interchange. Unfortunately, I don't remember
how I got his email and didn't add it to my address book, ...

Not to worry. Mr Vincent and I have exchanged comments already. I sent him
some NEC data and analysis which by his replies he did not appear to
understand. He seemed to think that I was trying to use NEC to analyze his
DLM designs -- saying that such was impossible.

But I wasn't attempting to do so. My NEC data only showed that his 3.5 MHz
standard DLM didn't perform very well as compared to a conventional
1/4-wave, unloaded monopole with a good r-f ground, and was about the equal
of a conventional monopole of the same physical height using the same r-f
ground -- which, of course, differs from his and the official URI test
report claims for the DLM.

RF

Vincent antenna
 

Richard Fry wrote:

...
Thanks, but a monopole of every electrical length is still a monopole, and
they ALL require a very good r-f ground or counterpoise for best
perfromance.

While your use of "best performance" may leave you wiggle room, however,
that statement is, for the most part, BULL PUCKY! 1/2 wave monopoles
have little dependence of a full counterpoise or ground for, at least,
acceptable performance. Anyone playing with them on wood/fiberglass
fresh water marine craft will have that realization and knowledge.

Not to worry. Mr Vincent and I have exchanged comments already. I sent him
some NEC data and analysis which by his replies he did not appear to
understand. He seemed to think that I was trying to use NEC to analyze his
DLM designs -- saying that such was impossible.

OH MY GAWD! Well then, you must forgive the man, he simply didn't
realize who he was dealing with!!! Krist, all he is surrounded by there
with is masters, doctorates, scholars, etc. He made the simple mistake
of NOT ignoring them and paying attention to your words of great wisdom
.... now let me see, what is your credentials--doctorate in amateur radio?


But I wasn't attempting to do so. My NEC data only showed that his 3.5 MHz
standard DLM didn't perform very well as compared to a conventional
1/4-wave, unloaded monopole with a good r-f ground, and was about the equal
of a conventional monopole of the same physical height using the same r-f
ground -- which, of course, differs from his and the official URI test
report claims for the DLM.

RF

I don't believe any of the modeling programs are "aware" of what
dynamics are causing the DLM to outperform expected/modeled results--or,
simply put, if all you can do is model and naysay--the antenna sucks.
Build one ACCORDING TO VINCENTS DATA and you will use it ... spacing
between coils is critical, values of the coils are critical, and the
ratio of inductance between coils is critical--by critical, I mean these
factors GREATLY depend on following Vincents design closely--the antenna
is HIGHLY SCALABLE, i.e. every aspect of a 1/2 wave is 2x that of a 1/4,
etc.

When I spoke to him, he was a bit "aggravated" by know-it-all-hams who
had personally attacked him--none of which had apparently built a
prototype first! When did you say you had spoken to Mr. Vincent? ROFLOL

Regards,
JS

Vincent antenna
 

"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

Vincent antenna
 

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

Vincent antenna
 

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.

Vincent antenna
 

"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

Vincent antenna
 

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

Vincent antenna
 

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

Vincent antenna
 

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

Vincent antenna
 

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

Vincent antenna
 

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

Vincent antenna
 

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

Vincent antenna
 

Richard Fry wrote:
"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.

Nobody said the Zepp antenna is free of common-
mode currents. The wire connected to the antenna
obviously carries current while the floating wire
just as obviously carries no current at the open
end. Radiation from the series stub just didn't
matter with the Zeppelin airships.
--
73, Cecil http://www.w5dxp.com

Vincent antenna
 

On Nov 27, 5:31 am, "Richard Fry" wrote:
"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

It doesn't matter. He mounted one on his bike, and he can
make contacts, so all the rules go out the window... :/
What I'd still like to see is the reinvention compared against
a same height short monopole which is purely top hat loaded.
I bet the DLM reinvention loses a bit of it's gee whiz status...
If the DLM is all it's cracked up to be, the LW aircraft beacon
boys should all be switching over real soon..
I'm not going to hold my breath waiting.. :(
Using extended helical windings for short whips is nothing new
either.
The CB'ers have been doing it for years and years.
It's a valid concept which in *some* cases can give an
advantage, but it sure isn't anything new.
People whine that no one tries the DLM in the real world.
But I already tried my own versions of basically the same thing
many years ago. "for mobile use"
But I don't use any versions of that basic design any more because
it is proven inferior vs other more standard methods such as
top hat loading, or using a single large high Q loading coil
instead of a bunch of split narrow wound coils of lower Q and
higher overall loss.
I still stand by my previous statements that the DLM is not an
optimum design for a short vertical. It has various warts, which
I won't bother elaborating on.. There is not much point since it
will just fly off into space ignored by the usual DLM-Gaussian
campers.
MK

Vincent antenna
 

On 27 Nov, 11:01, Cecil Moore wrote:
Richard Fry wrote:
"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.

Nobody said the Zepp antenna is free of common-
mode currents. The wire connected to the antenna
obviously carries current while the floating wire
just as obviously carries no current at the open
end. Radiation from the series stub just didn't
matter with the Zeppelin airships.
--
73, Cecil http://www.w5dxp.com

Cecil
W8JI is a competant engineer and well versed in "traditional"
antenna design but he is not without fault or error since
he is a human being. It is very worthwhile to read what
he has to say but if it doesn't agree on your thoughts
developed from first principles then you can't use the
info until the error is resolved. That is just like
reading a book without exercising discretion with
respect to the source.
Regards
Art

Vincent antenna
 

On 27 Nov, 10:48, Richard Clark wrote:
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- Hide quoted text -

- Show quoted text -

What ever you want.There is nothing more to discuss
with you. Send what you refee to as your missives elswhere

Vincent antenna
 

"art" wrote
W8JI is a competant engineer and well versed in "traditional"
antenna design but he is not without fault or error since
he is a human being. It is very worthwhile to read what
he has to say but if it doesn't agree on your thoughts
developed from first principles then you can't use the
info until the error is resolved. That is just like
reading a book without exercising discretion with
respect to the source.
_____________

art,

As presumably you, also, are a human being, then shouldn't we all consider
the peculiar, unproven, and unique beliefs you post here with the same
discretion applying to you as you suggest for the statements of W8JI (and
others)?

And that is being rather charitable, as W8JI is basing his analyses on
proven and repeatable physics, not on the speculations you continue to post,
and which no one else has offered the least bit of provable corroboration.

RF

Vincent antenna
 

On Tue, 27 Nov 2007 14:08:39 -0800 (PST), art
wrote:

On 27 Nov, 10:48, Richard Clark wrote:
On Tue, 27 Nov 2007 10:32:46 -0800 (PST), art
wrote:
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

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?

What ever you want.There is nothing more to discuss
with you. Send what you refee to as your missives elswhere

Hi Arthur,

So basically you are telling us you don't know how to distinguish a
hollow conductor from a solid one based on practical testing
demonstrating how an hollow conductor will "blow a fuse when RF is
applied to it." [No one is surprised you can't perform this.]

73's
Richard Clark, KB7QHC

Vincent antenna
 

On 27 Nov, 14:42, "Richard Fry" wrote:
"art" wrote W8JI is a competant engineer and well versed in "traditional"
antenna design but he is not without fault or error since
he is a human being. It is very worthwhile to read what
he has to say but if it doesn't agree on your thoughts
developed from first principles then you can't use the
info until the error is resolved. That is just like
reading a book without exercising discretion with
respect to the source.

_____________

art,

As presumably you, also, are a human being, then shouldn't we all consider
the peculiar, unproven, and unique beliefs you post here with the same
discretion applying to you as you suggest for the statements of W8JI (and
others)?

And that is being rather charitable, as W8JI is basing his analyses on
proven and repeatable physics, not on the speculations you continue to post,
and which no one else has offered the least bit of provable corroboration.

RF

What others think matters not to me. If I can follow thru from first
principles
of that which is stated then I am comfortable with it.
At the same time it is acknoweledged that radiation is still a mystery
to scientists
and I want to get to the bottom of things. If you are comfortable in
what you believe
then why the problem?

Vincent antenna
 

"art" wrote
At the same time it is acknoweledged that radiation
is still a mystery to scientists.
__________

Or just a mystery to you, perhaps?

Please quote the provable, scientific source(s) supporting an objective
research result showing that your stated belief that "radiation is still a
mystery" is valid.

RF

Vincent antenna
 

On Tue, 27 Nov 2007 16:42:27 -0800 (PST), art
wrote:

If I can follow thru from first
principles

Follow thru indeed.

This isn't rec.golf.clinic, and you can't even bogey the course. ;-)

Vincent antenna
 

On 27 Nov, 17:05, "Richard Fry" wrote:
"art" wrote At the same time it is acknoweledged that radiation
is still a mystery to scientists.

__________

Or just a mystery to you, perhaps?

Please quote the provable, scientific source(s) supporting an objective
research result showing that your stated belief that "radiation is still a
mystery" is valid.

RF

I figured you were from the "All is known about antennas" group.
Why are you bothering with me when all is known?
We have nothing in common so why are you trying to advise me?
Why not educate the masses with respect to waves versus particles,
everybody will be very interested as to what emanates from a
radiator or visa versa when on the receiving end.Is it clones of
yourself that is needed to save the World?
As for you wanting me to quote something per your request,
you can forget all about that! I am not interested in
influencing your thoughts, What you have you can take to your
grave with complete confidence.