"Sal M. Onella" wrote in message
...

"christofire" wrote in message
...
In the words of the great Basil Fawlty "you'll like this one"!

It appears to be believed, by one or two who frequent this NG, that a
tilted
monopole provides more gain and somehow 'better' EM radiation than a
vertical one. However, we've seen that tilting a vertical monopole
distorts
its radiation pattern so it is no longer truly omni-directional in the
horizontal plane. Then why not create an array of such tilted monopoles,
all tilted in different directions, to restore the omni-directional
pattern.

The result is a discone antenna, or a discage like the one illustrated at
http://gvarc.us/GVARCFrames/Titan/Di...ch4life002.jpg. I wonder
what
the 'new-age theorists' would make of this. Does it require the Coriolis
effect to analyse it, or is the old-fashioned version provided by
Schellkunoff & Friis(#) still adequate?



Such a design also appears as a self-supporting HF receive antenna the
Navy
mounted on the forward gun mount. I
struggled to find a picture of a ship with one showing but no luck. The
elements were about five to seven feet long and arranged as the OP
describes.


USS Missouri http://www.kh6bb.org/photos2.html

Chris

In the case of a single monopole mounted with its base at earth level,
adding tilt to it makes very little difference in its gain at
elevation angles up to +60 degrees or so, at any azimuth. It does
partially fill the elevation null at the zenith produced by the
vertical monopole, as well as to produce a small amount of h-pol
radiation over most of the compass.

Modeling this in NEC for a 1 MHz, 1/4-wave, straight monopole by
moving its top 10 meters out of plumb changed its peak gain by about
0.01 dB compared to the untilted version, at any azimuth.

RF

On Sep 8, 11:00*am, Richard Fry wrote:
In the case of a single monopole mounted with its base at earth level,
adding tilt to it makes very little difference in its gain at
elevation angles up to +60 degrees or so, at any azimuth. *It does
partially fill the elevation null at the zenith produced by the
vertical monopole, as well as to produce a small amount of h-pol
radiation over most of the compass.

Modeling this in NEC for a 1 MHz, 1/4-wave, straight monopole by
moving its top 10 meters out of plumb changed its peak gain by about
0.01 dB compared to the untilted version, at any azimuth.

RF

Gain has never been as issue in tipping the radiator except for some
who which to interject it.
Pointing's vector shows a radiation patterm that is spherical and in a
state of equilibrium
It is not the radiation pattern of a donut which all are familiar
with. Thus if one wants coverage in all directions one must pursue an
array or conductor in equilibrium.
The present state of the art only considers gravity as being outside
the arbitrary border
such that the equal and opposite vecter is exactly that. ie at right
angles to the Earth's surface. Now we all know that the radiation
pattern of such does not remotely resemble that of Pointings vector!
To get to the point of a spherical radiation pattern one must
recognize that there is an additional vector outside the boundary that
one must consider to obtain equilibrium. So far you have shown
progress by tipping the radiator where it started to fill the void at
the center of the donut. This alone confirms the idea that another
vector has to be considered outside the arbitrary border. Now
rotation is an essential property
of the Universe as fracture of an arbitrary boundary is created by two
forces which are not on a common plane. This is a shear force which
also creates torque or spin ,so it stands to reason that the other
force in combination with gravity is a force of torque or rotation.
If Coriolis is not that vector what other characteristic fits the
bill?

On Sep 8, 12:30*pm, Art Unwin wrote:
So far you have shown
progress by tipping the radiator where it started to fill the void at
the center of the donut. This alone confirms the idea that another
vector has to be considered outside the arbitrary border

The change in the elevation pattern shape and gains seen in the
"tipped" NEC plot I posted are NOT due to equilibrium, vectors outside
boundaries, shear forces, torque, spin etc.

The change in the pattern of the tipped vertical dipole are due to
changes in the amount and direction of the energy radiated toward the
earth by, and near the antenna, and the net field that results by the
vector addition of that reflection with the energy radiated in a given
direction by the dipole itself.

Suggest you use NEC to model a vertical dipole in free space, at
several physical rotation angles away from plumb. See if the gain and
shape of the radiation pattern changes (they won't, if your model is
valid).

Also note that the Poynting vector does not take the form of a perfect
sphere for any linear antenna -- only for a (non-existent) isotropic
radiator.

RF

On Sep 8, 1:02*pm, Richard Fry wrote:
On Sep 8, 12:30*pm, Art Unwin wrote:

So far you have shown
progress by tipping the radiator where it started to fill the void at
the center of the donut. This alone confirms the idea that another
vector has to be considered outside the arbitrary border

The change in the elevation pattern shape and gains seen in the
"tipped" NEC plot I posted are NOT due to equilibrium, vectors outside
boundaries, shear forces, torque, spin etc.

The change in the pattern of the tipped vertical dipole are due to
changes in the amount and direction of the energy radiated toward the
earth by, and near the antenna, and the net field that results by the
vector addition of that reflection with the energy radiated in a given
direction by the dipole itself.

Suggest you use NEC to model a vertical dipole in free space, at
several physical rotation angles away from plumb. *See if the gain and
shape of the radiation pattern changes (they won't, if your model is
valid).

Also note that the Poynting vector does not take the form of a perfect
sphere for any linear antenna -- only for a (non-existent) isotropic
radiator.

RF

We have now come to the end of my input.
We choose to disagree. I can go along with that
just to get you and others off my back. I will go away
and let all mumble about things between themselves.
I need a vacation this year anyway and the kids are back in school
so it is a good time and the weather is just right.
This month will be momentous at the UN so a seat in the gallery sound
good
We will see.

There are many spelling mistakes in your random word generator.
olivier

Art Unwin wrote:
On Sep 8, 11:00 am, Richard Fry wrote:
In the case of a single monopole mounted with its base at earth level,
adding tilt to it makes very little difference in its gain at
elevation angles up to +60 degrees or so, at any azimuth. It does
partially fill the elevation null at the zenith produced by the
vertical monopole, as well as to produce a small amount of h-pol
radiation over most of the compass.

Modeling this in NEC for a 1 MHz, 1/4-wave, straight monopole by
moving its top 10 meters out of plumb changed its peak gain by about
0.01 dB compared to the untilted version, at any azimuth.

RF

Gain has never been as issue in tipping the radiator except for some
who which to interject it.
Pointing's vector shows a radiation patterm that is spherical and in a
state of equilibrium
It is not the radiation pattern of a donut which all are familiar
with. Thus if one wants coverage in all directions one must pursue an
array or conductor in equilibrium.
The present state of the art only considers gravity as being outside
the arbitrary border
such that the equal and opposite vecter is exactly that. ie at right
angles to the Earth's surface. Now we all know that the radiation
pattern of such does not remotely resemble that of Pointings vector!
To get to the point of a spherical radiation pattern one must
recognize that there is an additional vector outside the boundary that
one must consider to obtain equilibrium. So far you have shown
progress by tipping the radiator where it started to fill the void at
the center of the donut. This alone confirms the idea that another
vector has to be considered outside the arbitrary border. Now
rotation is an essential property
of the Universe as fracture of an arbitrary boundary is created by two
forces which are not on a common plane. This is a shear force which
also creates torque or spin ,so it stands to reason that the other
force in combination with gravity is a force of torque or rotation.
If Coriolis is not that vector what other characteristic fits the
bill?

Art Unwin wrote:
On Sep 8, 11:00 am, Richard Fry wrote:
In the case of a single monopole mounted with its base at earth level,
adding tilt to it makes very little difference in its gain at
elevation angles up to +60 degrees or so, at any azimuth. It does
partially fill the elevation null at the zenith produced by the
vertical monopole, as well as to produce a small amount of h-pol
radiation over most of the compass.

Modeling this in NEC for a 1 MHz, 1/4-wave, straight monopole by
moving its top 10 meters out of plumb changed its peak gain by about
0.01 dB compared to the untilted version, at any azimuth.

RF

Gain has never been as issue in tipping the radiator except for some
who which to interject it.
Pointing's vector shows a radiation patterm that is spherical and in a
state of equilibrium
It is not the radiation pattern of a donut which all are familiar
with. Thus if one wants coverage in all directions one must pursue an
array or conductor in equilibrium.

The "donut" is a red herring. It's a visualization, not a blob of RF
coming off the antenna. All antennas radiate in all directions. Some
directions are higher intensity than others, but all directions none the
less. The donut just exists to help us put a number on what is happening.


rotation is an essential property
of the Universe as fracture of an arbitrary boundary is created by two
forces which are not on a common plane. This is a shear force which
also creates torque or spin ,so it stands to reason that the other
force in combination with gravity is a force of torque or rotation.
If Coriolis is not that vector what other characteristic fits the
bill?

So Coriolis needs re-defined also as not a mechanical *effect*, but as
an electrical *force* that compels objects or energy to rotate.

I'll not be so beholden to summarily reject what you are saying, but
what you are talking about wold have to be something other than Coriolis
effect, it would have to be a as yet undefined and un named force.

- 73 de Mike N3LI -

"christofire" wrote in message
...

snip


Such a design also appears as a self-supporting HF receive antenna the
Navy
mounted on the forward gun mount. I
struggled to find a picture of a ship with one showing but no luck. The
elements were about five to seven feet long and arranged as the OP
describes.


USS Missouri http://www.kh6bb.org/photos2.html

Chris



Chris, that's the discone/cage, a transmit antenna with two individual
feedlines from the Radio Room. Some people call it the discage, as on the
website, but I never did.

The cage portion radiates 4 - 12 MHz and the discone portion radiates 10-30.
IIRC, it stands more than 20 feet high.

The antenna I'm trying to remember was receive only and was less than 6 feet
high. It had a shape that sort of resembled a squat wire basket.

Sal

"Sal M. Onella" wrote in message
news

"christofire" wrote in message
...

snip


Such a design also appears as a self-supporting HF receive antenna the
Navy
mounted on the forward gun mount. I
struggled to find a picture of a ship with one showing but no luck.
The
elements were about five to seven feet long and arranged as the OP
describes.


USS Missouri http://www.kh6bb.org/photos2.html

Chris



Chris, that's the discone/cage, a transmit antenna with two individual
feedlines from the Radio Room. Some people call it the discage, as on the
website, but I never did.

The cage portion radiates 4 - 12 MHz and the discone portion radiates
10-30.
IIRC, it stands more than 20 feet high.

The antenna I'm trying to remember was receive only and was less than 6
feet
high. It had a shape that sort of resembled a squat wire basket.

Sal


Sal,

There's a directory of antennas used at one time or another by the US Navy
at http://www.combatindex.com/hardware/...nsor_main.html. Could it
be the AS-2231? The 'discage' appears to be the AS-2802. Also, a
contributor to this group, Richard Clark, has some photos at
http://home.comcast.net/~kb7qhc/antennas/navy/.

I was aware that the discage in at least one of its incarnations had two
separate feed lines, and the combination of two antennas in one 'package'
gives rise to its particular shape. However, it has always intrigued me
that a single element of similar shape has been used since the early 50s by
the British Navy in the AJE/UK-SRA-102:
http://middle-watch.com/communications.htm and
http://rnmuseumradarandcommunication...org.uk/AJE.pdf. This could be a
coincidence or it could be that F. A. Kitchen, the designer of the AJE, had
been influenced by having previously seen a discage (his paper about
development of the AJE doesn't really explain where the shape comes from).
So I wonder when the AS-2802 'discage' came into use?

Chris

"christofire" wrote in message
...


snip

The antenna I'm trying to remember was receive only and was less than 6
feet
high. It had a shape that sort of resembled a squat wire basket.

Sal


Sal,

There's a directory of antennas used at one time or another by the US Navy
at http://www.combatindex.com/hardware/...nsor_main.html. Could
it
be the AS-2231?

No, that's called a sleeve, I think, but I moused over the MIL nomenclatures
and looked at each picture. The antenna I was thinking of is the
AS-2866/SRR. I am surprised to see in the write-up that it's only 24 inches
tall. I thought twice that.


I used that website many times when I was working (prior to June, 2007) and
was wishing I had saved the link on my home computer. Now I have it again
:-)))


I was aware that the discage in at least one of its incarnations had two
separate feed lines, and the combination of two antennas in one 'package'
gives rise to its particular shape. However, it has always intrigued me
that a single element of similar shape has been used since the early 50s
by
the British Navy in the AJE/UK-SRA-102:
http://middle-watch.com/communications.htm and
http://rnmuseumradarandcommunication...org.uk/AJE.pdf. This could be a
coincidence or it could be that F. A. Kitchen, the designer of the AJE,
had
been influenced by having previously seen a discage (his paper about
development of the AJE doesn't really explain where the shape comes from).
So I wonder when the AS-2802 'discage' came into use?

I think it was removed from USS Dubuque (LPD-7) during the ship's overhaul
in 1982/83. I was there but the memory gets a little hazy about such
details. If that recollection is correct, it predates the 1980s.