The Lindenblad has an overhead null that you might find anoying for some
high elevation passes of LEOs.
Are you open to trying to build a DCA (which is an antenna that I
developed)? I make the claim that there is no other hemispheric coverage
antenna design that performs better than a DCA. But, I sure am open to
being corrected.
The Feb 2008 QST contains an article on the DCA antenna design concept.
It is my claim that a DCA is extreemely forgiving of construction errors
and uses 4 wire dipoles and 50 ohm coax with 5 RFI type ferrites as
"baluns'.

Jerry KD6JDJ
Given the fact I don't subscribe to QST, domicile Australia, would you have
a copy of the article?

HH

"Roy Lewallen" wrote in message
treetonline...
I've found quite a variation in foamed dielectric cable velocity factor
from lot to lot of the same brand and type, even with major brands.
Apparently they don't control the density of the dielectric very well. So
if you're planning on using foamed dielectric cable in an application
where VF is important, I highly recommend that you measure the VF of a
sample from the same piece you'll be using.

Roy Lewallen, W7EL

I second that Roy,
Each time we start a new spool (same mfg) we have to remeasure the V.F.-
RG-11U foam.
I too believe it is the foam density that is not well controlled.

Dale W4OP

"Harry H" wrote in message
...

The Lindenblad has an overhead null that you might find anoying for some
high elevation passes of LEOs.
Are you open to trying to build a DCA (which is an antenna that I
developed)? I make the claim that there is no other hemispheric
coverage antenna design that performs better than a DCA. But, I sure am
open to being corrected.
The Feb 2008 QST contains an article on the DCA antenna design concept.
It is my claim that a DCA is extreemely forgiving of construction errors
and uses 4 wire dipoles and 50 ohm coax with 5 RFI type ferrites as
"baluns'.

Jerry KD6JDJ
Given the fact I don't subscribe to QST, domicile Australia, would you
have a copy of the article?

HH


Hi HH

It would be my pleasure to disclose any/all the information I have
relating to the DCA antenna design concept. It is simple. It is two pairs
of crossed dipoles. Each pair is spaced 1/4 wave apart and fed in phase.
One pair is physically mounted 90 degrees from the other pair. All four
dipoles are tilted 30 degtrees from vertical. One pair is fed 90 degrees
later than the other pair.
The concept is so simple and straightfoeward that it is probable that the
concept has been developed before I thought of it. But, I have been unable
to find anything published related to this simple "Double Cross Antenna"
I told my *Internet buddy*, Patrik Tast, in Finland about the concept and
he found it to be exactly what he needed for reception of NOAA weather
satellite signals. Patrik publishes alot of what I send him related to the
antenna. Patrik shows a section of his web page to describe the DCA to
anyone interested. You can find the QST article in the section Patrik
identifies as ANTENNAS on the first page of his site
http://www.poes-weather.com/index.php.

If you have any questions about the DCA concept you are free to E-mail me,
anytime. Or, if you have any facts or data to show where I am wrong about
how well this antenna performs, or know of something that performs better,
please set me straight.

Jerry KD6JDJ

"Jerry" wrote in message
...

"Harry H" wrote in message
...

The Lindenblad has an overhead null that you might find anoying for
some high elevation passes of LEOs.
Are you open to trying to build a DCA (which is an antenna that I
developed)? I make the claim that there is no other hemispheric
coverage antenna design that performs better than a DCA. But, I sure
am open to being corrected.
The Feb 2008 QST contains an article on the DCA antenna design concept.
It is my claim that a DCA is extreemely forgiving of construction
errors and uses 4 wire dipoles and 50 ohm coax with 5 RFI type ferrites
as "baluns'.

Jerry KD6JDJ
Given the fact I don't subscribe to QST, domicile Australia, would you
have a copy of the article?

HH


Hi HH

It would be my pleasure to disclose any/all the information I have
relating to the DCA antenna design concept. It is simple. It is two
pairs of crossed dipoles. Each pair is spaced 1/4 wave apart and fed in
phase. One pair is physically mounted 90 degrees from the other pair.
All four dipoles are tilted 30 degtrees from vertical. One pair is fed
90 degrees later than the other pair.
The concept is so simple and straightfoeward that it is probable that the
concept has been developed before I thought of it. But, I have been
unable to find anything published related to this simple "Double Cross
Antenna"
I told my *Internet buddy*, Patrik Tast, in Finland about the concept and
he found it to be exactly what he needed for reception of NOAA weather
satellite signals. Patrik publishes alot of what I send him related to
the antenna. Patrik shows a section of his web page to describe the DCA
to anyone interested. You can find the QST article in the section Patrik
identifies as ANTENNAS on the first page of his site
http://www.poes-weather.com/index.php.

If you have any questions about the DCA concept you are free to E-mail
me, anytime. Or, if you have any facts or data to show where I am wrong
about how well this antenna performs, or know of something that performs
better, please set me straight.

Jerry KD6JDJ


.... but surely this is the same as a Lindenblad array? The tilt of the
dipoles was always a parameter in the Lindenblad, so I wonder how your DCA
differs from what N. E. Lindenblad described in the April 1941 edition of
'Communications'.

Chris

"christofire" wrote in message
...
"Jerry" wrote in message
...

"Harry H" wrote in message
...

The Lindenblad has an overhead null that you might find anoying for
some high elevation passes of LEOs.
Are you open to trying to build a DCA (which is an antenna that I
developed)? I make the claim that there is no other hemispheric
coverage antenna design that performs better than a DCA. But, I sure
am open to being corrected.
The Feb 2008 QST contains an article on the DCA antenna design
concept.
It is my claim that a DCA is extreemely forgiving of construction
errors and uses 4 wire dipoles and 50 ohm coax with 5 RFI type ferrites
as "baluns'.

Jerry KD6JDJ
Given the fact I don't subscribe to QST, domicile Australia, would you
have a copy of the article?

HH


Hi HH

It would be my pleasure to disclose any/all the information I have
relating to the DCA antenna design concept. It is simple. It is two
pairs of crossed dipoles. Each pair is spaced 1/4 wave apart and fed in
phase. One pair is physically mounted 90 degrees from the other pair. All
four dipoles are tilted 30 degtrees from vertical. One pair is fed 90
degrees later than the other pair.
The concept is so simple and straightfoeward that it is probable that
the concept has been developed before I thought of it. But, I have been
unable to find anything published related to this simple "Double Cross
Antenna"
I told my *Internet buddy*, Patrik Tast, in Finland about the concept
and he found it to be exactly what he needed for reception of NOAA
weather satellite signals. Patrik publishes alot of what I send him
related to the antenna. Patrik shows a section of his web page to
describe the DCA to anyone interested. You can find the QST article in
the section Patrik identifies as ANTENNAS on the first page of his site
http://www.poes-weather.com/index.php.

If you have any questions about the DCA concept you are free to E-mail
me, anytime. Or, if you have any facts or data to show where I am wrong
about how well this antenna performs, or know of something that performs
better, please set me straight.

Jerry KD6JDJ


... but surely this is the same as a Lindenblad array? The tilt of the
dipoles was always a parameter in the Lindenblad, so I wonder how your DCA
differs from what N. E. Lindenblad described in the April 1941 edition of
'Communications'.

Chris


Hi Chris

Several, well educated, antenna experts insist that the DCA is actually a
Lindenblad. If you thought the DCA is a Lindenblad, you are not alone.
The DCA is not a Lindenblad. The array of four dipoles in a Lindenblad
are fed to produce an overhead null. The four dipoles in a DCA are fed to
produce no overhead null. The DCA is a hemispheric coverage CP antenna.
The Lindenblad is not.
Let me know if you have reason to consider the DCA to be the same as a
Lindenblad. I knew nothing about Lindenblad until after recognizing the
DCA concept.

Jerry m KD6JDJ

Jerry

You might want to consider using RG-6/u instead of RG-59. These daze,
the quality of RG-59 coax is rather marginal. I've seen 80% coverage


Beware of the Aluminum foil and shields though. Once it gets wet there is
no stopping the internal corrosion and will generate broadband noise under
power. This includes both RG6 and 9913 and LMR types. They have been
banned from all commercial sites around here.

Bring a knife with you and inspect before you buy. Tinned Copper braid is
better, Silver clad rigid is best.

On Feb 10, 1:57*am, "Jerry" wrote:
"Harry H" wrote in message

...





*The Lindenblad has an overhead null that you might find anoying for some
high elevation passes of LEOs.
*Are you open to trying to build a DCA (which is an antenna that I
developed)? * I make the claim that there is no other hemispheric
coverage antenna design that performs better than a DCA. * But, I sure am
open to being corrected.
*The Feb 2008 QST contains an article on the DCA antenna design concept.
*It is my claim that a DCA is extreemely forgiving of construction errors
and uses 4 wire dipoles and 50 ohm coax with 5 RFI type ferrites as
"baluns'.

* * * * * * * * * * * *Jerry * KD6JDJ
Given the fact I don't subscribe to QST, domicile Australia, would you
have a copy of the article?

HH

* Hi HH

* It would be my pleasure to disclose any/all the information I have
relating to the DCA antenna design concept. * It is simple. *It is two pairs
of crossed dipoles. * Each pair is spaced 1/4 wave apart and fed in phase.
One pair is physically mounted 90 degrees from the other pair. * All four
dipoles are tilted 30 degtrees from vertical. * One pair is fed 90 degrees
later than the other pair.
* The concept is so simple and straightfoeward that it is probable that the
concept has been developed before I thought of it. * But, I have been unable
to find anything published related to this simple "Double Cross Antenna"
* I told my *Internet buddy*, Patrik Tast, in Finland about the concept and
he found it to be exactly what he needed for reception of NOAA weather
satellite signals. * Patrik publishes alot of what I send him related to the
antenna. *Patrik shows a section of his web page to describe the DCA to
anyone interested. * You can find the QST article in the section Patrik
identifies as ANTENNAS on the first page of his sitehttp://www.poes-weather.com/index.php.

* If you have any questions about the DCA concept you are free to E-mail me,
anytime. * Or, if you have any facts or data to show where I am wrong about
how well this antenna performs, *or know of something that performs better,
please set me straight.

* * * * * * * Jerry * *KD6JDJ

Looked at the URL
What this antenna is doing is to aproach equilibrium by taking into
account the "weak force" which demands a tilting away from parallelism
or the verticle position away from the surface of the earth, without
which the radiation pattern will not be balanced.
When a U.S.naval base tipped all its verticle antennas at an angle
referenced to earth this prior null must have been of great
inconvenience with respect to defense alertness.

"Jerry" wrote in message
...

"christofire" wrote in message
...
"Jerry" wrote in message
...

"Harry H" wrote in message
...

The Lindenblad has an overhead null that you might find anoying for
some high elevation passes of LEOs.
Are you open to trying to build a DCA (which is an antenna that I
developed)? I make the claim that there is no other hemispheric
coverage antenna design that performs better than a DCA. But, I sure
am open to being corrected.
The Feb 2008 QST contains an article on the DCA antenna design
concept.
It is my claim that a DCA is extreemely forgiving of construction
errors and uses 4 wire dipoles and 50 ohm coax with 5 RFI type
ferrites as "baluns'.

Jerry KD6JDJ
Given the fact I don't subscribe to QST, domicile Australia, would you
have a copy of the article?

HH


Hi HH

It would be my pleasure to disclose any/all the information I have
relating to the DCA antenna design concept. It is simple. It is two
pairs of crossed dipoles. Each pair is spaced 1/4 wave apart and fed
in phase. One pair is physically mounted 90 degrees from the other pair.
All four dipoles are tilted 30 degtrees from vertical. One pair is fed
90 degrees later than the other pair.
The concept is so simple and straightfoeward that it is probable that
the concept has been developed before I thought of it. But, I have
been unable to find anything published related to this simple "Double
Cross Antenna"
I told my *Internet buddy*, Patrik Tast, in Finland about the concept
and he found it to be exactly what he needed for reception of NOAA
weather satellite signals. Patrik publishes alot of what I send him
related to the antenna. Patrik shows a section of his web page to
describe the DCA to anyone interested. You can find the QST article in
the section Patrik identifies as ANTENNAS on the first page of his site
http://www.poes-weather.com/index.php.

If you have any questions about the DCA concept you are free to E-mail
me, anytime. Or, if you have any facts or data to show where I am
wrong about how well this antenna performs, or know of something that
performs better, please set me straight.

Jerry KD6JDJ


... but surely this is the same as a Lindenblad array? The tilt of the
dipoles was always a parameter in the Lindenblad, so I wonder how your
DCA differs from what N. E. Lindenblad described in the April 1941
edition of 'Communications'.

Chris


Hi Chris

Several, well educated, antenna experts insist that the DCA is actually a
Lindenblad. If you thought the DCA is a Lindenblad, you are not alone.
The DCA is not a Lindenblad. The array of four dipoles in a Lindenblad
are fed to produce an overhead null. The four dipoles in a DCA are fed
to produce no overhead null. The DCA is a hemispheric coverage CP
antenna. The Lindenblad is not.
Let me know if you have reason to consider the DCA to be the same as a
Lindenblad. I knew nothing about Lindenblad until after recognizing the
DCA concept.

Jerry m KD6JDJ

Jerry


Perhaps it's a rather fine distinction to say an antenna that has the same
physical form as the Lindenblad array is something different because the
elements are driven differently. The original version that he patented
didn't have rod elements at all (see, for example,
http://www.coe.montana.edu/ee/rwolff...B_antennas.pdf )
but it was the configuration of four slanted dipoles around a central pole
that appears to have borne his name since 1941. Henry Jasik's 'Antenna
Engineering Handbook' (now by John L. Volakis, Richard C. Johnson and Henry
Jasik, Chapter 29, Page 34) refers to the configuration as a Lindenblad
array, without being specific about the way the dipoles are driven.
However, applying new names to antennas that exploit well known
configurations seems fairly commonplace in the professional field,
particularly in broadcasting.

Of course you can name your antenna as you please, but there might be some
value in mentioning that it is a development of the Lindenblad array - you'd
certainly need to demonstrate awareness of, and distinction from, the prior
art if you were to seek a patent.

Chris

"Art Unwin" wrote in message
...
On Feb 10, 1:57 am, "Jerry" wrote:
"Harry H" wrote in message

...





The Lindenblad has an overhead null that you might find anoying for
some
high elevation passes of LEOs.
Are you open to trying to build a DCA (which is an antenna that I
developed)? I make the claim that there is no other hemispheric
coverage antenna design that performs better than a DCA. But, I sure am
open to being corrected.
The Feb 2008 QST contains an article on the DCA antenna design concept.
It is my claim that a DCA is extreemely forgiving of construction
errors
and uses 4 wire dipoles and 50 ohm coax with 5 RFI type ferrites as
"baluns'.

Jerry KD6JDJ
Given the fact I don't subscribe to QST, domicile Australia, would you
have a copy of the article?

HH

Hi HH

It would be my pleasure to disclose any/all the information I have
relating to the DCA antenna design concept. It is simple. It is two pairs
of crossed dipoles. Each pair is spaced 1/4 wave apart and fed in phase.
One pair is physically mounted 90 degrees from the other pair. All four
dipoles are tilted 30 degtrees from vertical. One pair is fed 90 degrees
later than the other pair.
The concept is so simple and straightfoeward that it is probable that the
concept has been developed before I thought of it. But, I have been unable
to find anything published related to this simple "Double Cross Antenna"
I told my *Internet buddy*, Patrik Tast, in Finland about the concept and
he found it to be exactly what he needed for reception of NOAA weather
satellite signals. Patrik publishes alot of what I send him related to the
antenna. Patrik shows a section of his web page to describe the DCA to
anyone interested. You can find the QST article in the section Patrik
identifies as ANTENNAS on the first page of his
sitehttp://www.poes-weather.com/index.php.

If you have any questions about the DCA concept you are free to E-mail me,
anytime. Or, if you have any facts or data to show where I am wrong about
how well this antenna performs, or know of something that performs better,
please set me straight.

Jerry KD6JDJ

Looked at the URL
What this antenna is doing is to aproach equilibrium by taking into
account the "weak force" which demands a tilting away from parallelism
or the verticle position away from the surface of the earth, without
which the radiation pattern will not be balanced.
When a U.S.naval base tipped all its verticle antennas at an angle
referenced to earth this prior null must have been of great
inconvenience with respect to defense alertness.

- - - -

A simpler explanation is that the tilt is there to provide a
horizontally-polarised component in the radiated field around the antenna,
as well as a vertically-polarised component, in order to achieve circular
polarisation. The angle of tilt is a design parameter which, along with the
radius of the centres of the dipoles and, in this case, the choice of how
they are phased, collectively determine the axial ratio. The radiation
patterns and match of such an antenna are not affected by its orientation
with respect to the surface of the earth!

Chris

"christofire" wrote in message
...

"Jerry" wrote in message
...

"christofire" wrote in message
...
"Jerry" wrote in message
...

"Harry H" wrote in message
...

The Lindenblad has an overhead null that you might find anoying for
some high elevation passes of LEOs.
Are you open to trying to build a DCA (which is an antenna that I
developed)? I make the claim that there is no other hemispheric
coverage antenna design that performs better than a DCA. But, I
sure am open to being corrected.
The Feb 2008 QST contains an article on the DCA antenna design
concept.
It is my claim that a DCA is extreemely forgiving of construction
errors and uses 4 wire dipoles and 50 ohm coax with 5 RFI type
ferrites as "baluns'.

Jerry KD6JDJ
Given the fact I don't subscribe to QST, domicile Australia, would you
have a copy of the article?

HH


Hi HH

It would be my pleasure to disclose any/all the information I have
relating to the DCA antenna design concept. It is simple. It is two
pairs of crossed dipoles. Each pair is spaced 1/4 wave apart and fed
in phase. One pair is physically mounted 90 degrees from the other
pair. All four dipoles are tilted 30 degtrees from vertical. One pair
is fed 90 degrees later than the other pair.
The concept is so simple and straightfoeward that it is probable that
the concept has been developed before I thought of it. But, I have
been unable to find anything published related to this simple "Double
Cross Antenna"
I told my *Internet buddy*, Patrik Tast, in Finland about the concept
and he found it to be exactly what he needed for reception of NOAA
weather satellite signals. Patrik publishes alot of what I send him
related to the antenna. Patrik shows a section of his web page to
describe the DCA to anyone interested. You can find the QST article
in the section Patrik identifies as ANTENNAS on the first page of his
site http://www.poes-weather.com/index.php.

If you have any questions about the DCA concept you are free to E-mail
me, anytime. Or, if you have any facts or data to show where I am
wrong about how well this antenna performs, or know of something that
performs better, please set me straight.

Jerry KD6JDJ


... but surely this is the same as a Lindenblad array? The tilt of the
dipoles was always a parameter in the Lindenblad, so I wonder how your
DCA differs from what N. E. Lindenblad described in the April 1941
edition of 'Communications'.

Chris


Hi Chris

Several, well educated, antenna experts insist that the DCA is actually
a Lindenblad. If you thought the DCA is a Lindenblad, you are not
alone.
The DCA is not a Lindenblad. The array of four dipoles in a Lindenblad
are fed to produce an overhead null. The four dipoles in a DCA are fed
to produce no overhead null. The DCA is a hemispheric coverage CP
antenna. The Lindenblad is not.
Let me know if you have reason to consider the DCA to be the same as a
Lindenblad. I knew nothing about Lindenblad until after recognizing the
DCA concept.

Jerry m KD6JDJ

Jerry


Perhaps it's a rather fine distinction to say an antenna that has the same
physical form as the Lindenblad array is something different because the
elements are driven differently. The original version that he patented
didn't have rod elements at all (see, for example,
http://www.coe.montana.edu/ee/rwolff...B_antennas.pdf
) but it was the configuration of four slanted dipoles around a central
pole that appears to have borne his name since 1941. Henry Jasik's
'Antenna Engineering Handbook' (now by John L. Volakis, Richard C. Johnson
and Henry Jasik, Chapter 29, Page 34) refers to the configuration as a
Lindenblad array, without being specific about the way the dipoles are
driven. However, applying new names to antennas that exploit well known
configurations seems fairly commonplace in the professional field,
particularly in broadcasting.

Of course you can name your antenna as you please, but there might be some
value in mentioning that it is a development of the Lindenblad array -
you'd certainly need to demonstrate awareness of, and distinction from,
the prior art if you were to seek a patent.

Chris


Hi Chris

I wonder if you have any pictures of a Lindenblad and any radiation plots.
I also wonder if an end fire antenna is the same as a broadside antenna when
they look the same from a distance.

Jerry KD6JDJ