There is a 3-phase transmitter feeding a 3-phase antenna via a 3-wire
transmission line.

The antenna consists of three 1/4-wave horizontal radiators spaced at
120 degee intervals.

Is the radiation pattern in the horizontal plane perfectly
omni-directional?
----
Reg.

Reg Edwards wrote:
There is a 3-phase transmitter feeding a 3-phase antenna via a 3-wire
transmission line.

The antenna consists of three 1/4-wave horizontal radiators spaced at
120 degee intervals.

Is the radiation pattern in the horizontal plane perfectly
omni-directional?
----
Reg.

Hi Reg, Is the 3-phase transmitter balanced with the output current
equal magnitude, and the phase angle exactly 120 degrees? Is the
3-phase antenna fed via a 3-wire transmission line, or three equal
length transmission lines? Us Amateurs don't have a lot of experience
with 3-wire coax. Are the horizontal radiators 1/4-wave, or 1/2 wave?
If they are 1/4 wave, or 1/2 wave and spaced 120 degrees in the
horizontal plane, doesn't that form an equilateral triangle? So, you
are feeding a triangular antenna whose sides are 1/4-wave in the centre
of each side with balanced 3-phase rf energy?
Even if you clarify this is I still won't know the answer to your
question until I model the array.
Gary N4AST

wrote in message
oups.com...

Reg Edwards wrote:
There is a 3-phase transmitter feeding a 3-phase antenna via a
3-wire
transmission line.

The antenna consists of three 1/4-wave horizontal radiators spaced
at
120 degee intervals.

Is the radiation pattern in the horizontal plane perfectly
omni-directional?
----
Reg.

Hi Reg, Is the 3-phase transmitter balanced with the output
current
equal magnitude, and the phase angle exactly 120 degrees? Is the
3-phase antenna fed via a 3-wire transmission line, or three equal
length transmission lines? Us Amateurs don't have a lot of
experience
with 3-wire coax. Are the horizontal radiators 1/4-wave, or 1/2
wave?
If they are 1/4 wave, or 1/2 wave and spaced 120 degrees in the
horizontal plane, doesn't that form an equilateral triangle? So,
you
are feeding a triangular antenna whose sides are 1/4-wave in the
centre
of each side with balanced 3-phase rf energy?
Even if you clarify this is I still won't know the answer to your
question until I model the array.
Gary N4AST
=======================================

The three antenna wires are like the spokes of a wheel, spaced at 120
degrees, and each 1/4-wave in length. All in the horizontal plane.

The transmission line is balanced about ground and each of the line
wires is connected to one of the three antenna elements at the center
of the wheel. There's no need to pull the line wires apart at the end
of the line.

What is the radiation pattern in the horizontal plane?

Also what is the equivalent load impedance between each of the line
wires.
----
Reg.

Reg Edwards wrote:
wrote in message
oups.com...

Reg Edwards wrote:
There is a 3-phase transmitter feeding a 3-phase antenna via a
3-wire
transmission line.

The antenna consists of three 1/4-wave horizontal radiators spaced
at
120 degee intervals.

Is the radiation pattern in the horizontal plane perfectly
omni-directional?
----
Reg.

Hi Reg, Is the 3-phase transmitter balanced with the output
current
equal magnitude, and the phase angle exactly 120 degrees? Is the
3-phase antenna fed via a 3-wire transmission line, or three equal
length transmission lines? Us Amateurs don't have a lot of
experience
with 3-wire coax. Are the horizontal radiators 1/4-wave, or 1/2
wave?
If they are 1/4 wave, or 1/2 wave and spaced 120 degrees in the
horizontal plane, doesn't that form an equilateral triangle? So,
you
are feeding a triangular antenna whose sides are 1/4-wave in the
centre
of each side with balanced 3-phase rf energy?
Even if you clarify this is I still won't know the answer to your
question until I model the array.
Gary N4AST
=======================================

The three antenna wires are like the spokes of a wheel, spaced at 120
degrees, and each 1/4-wave in length. All in the horizontal plane.

The transmission line is balanced about ground and each of the line
wires is connected to one of the three antenna elements at the center
of the wheel. There's no need to pull the line wires apart at the end
of the line.

What is the radiation pattern in the horizontal plane?

Also what is the equivalent load impedance between each of the line
wires.
----
Reg.
Ok, I was thinking in terms of a Delta configuration, and you were
thinking of a Star Configuration. Need more time. Did you consider a
Delta (triangle) configuration when you thought this up?
Gary N4AST

wrote in message
oups.com...

Reg Edwards wrote:
wrote in message
oups.com...

Reg Edwards wrote:
There is a 3-phase transmitter feeding a 3-phase antenna via a
3-wire
transmission line.

The antenna consists of three 1/4-wave horizontal radiators spaced
at
120 degee intervals.

Is the radiation pattern in the horizontal plane perfectly
omni-directional?
----
Reg.

Hi Reg, Is the 3-phase transmitter balanced with the output
current
equal magnitude, and the phase angle exactly 120 degrees? Is the
3-phase antenna fed via a 3-wire transmission line, or three equal
length transmission lines? Us Amateurs don't have a lot of
experience
with 3-wire coax. Are the horizontal radiators 1/4-wave, or 1/2
wave?
If they are 1/4 wave, or 1/2 wave and spaced 120 degrees in the
horizontal plane, doesn't that form an equilateral triangle? So,
you
are feeding a triangular antenna whose sides are 1/4-wave in the
centre
of each side with balanced 3-phase rf energy?
Even if you clarify this is I still won't know the answer to your
question until I model the array.
Gary N4AST
=======================================

The three antenna wires are like the spokes of a wheel, spaced at 120
degrees, and each 1/4-wave in length. All in the horizontal plane.

The transmission line is balanced about ground and each of the line
wires is connected to one of the three antenna elements at the center
of the wheel. There's no need to pull the line wires apart at the end
of the line.

What is the radiation pattern in the horizontal plane?

Also what is the equivalent load impedance between each of the line
wires.
----
Reg.
Ok, I was thinking in terms of a Delta configuration, and you were
thinking of a Star Configuration. Need more time. Did you consider a
Delta (triangle) configuration when you thought this up?
Gary N4AST

Actually, I think it is delta connected. A Y connection would Imply half
wave dipoles with their feedpoints connected between each of the three wires
and the neutral point. I am holding my breath for the answer.

Tam/WB2TT

With a delta connection the line wires would have to opened out at
their ends and would radiate just as much as the triangular antenna
itself.

With either delta or Y connection there is no 4th neutral wire. As the
whole system is balanced there would be zero current in the neutral
anyway.
----
Reg.

In article .com,
wrote:

Us Amateurs don't have a lot of experience

That's why they call you "Amateurs".....the Professional Radio Engineers
understand perfectly what the OP was talking about, and exactly why, and
how, this type of antenna system is used in the real world of
communications, both fixed and mobile.

Me who has been around the biz, since almost before Moses.....

Me wrote:
In article .com,
wrote:

Us Amateurs don't have a lot of experience

That's why they call you "Amateurs".....the Professional Radio Engineers
understand perfectly what the OP was talking about, and exactly why, and
how, this type of antenna system is used in the real world of
communications, both fixed and mobile.

Me who has been around the biz, since almost before Moses.....

I am glad they call me an Amateur, because that is what I am. The
word Amateur is in the name of this Newsgroup. It is obvious
Professional Radio Engineers would understand what Reg was talking
about, but this is an Amateur Newsgroup. Why don't you go to the
Professional Antenna Designer Newsgroup (if there is one) and ask the
question that Reg did? I don't think they would all understand
perfectly, but I may be wrong, because I am an amateur. By the way,
are you an Amateur Radio Operator?
Gary N4AST

In article .com,
wrote:

By the way, are you an Amateur Radio Operator?
Gary N4AST


Since 1964


Me

Me wrote:
In article .com,
wrote:


By the way, are you an Amateur Radio Operator?
Gary N4AST



Since 1964


Me

Awe! A newcomer!

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