On Sat, 27 Mar 2004 21:41:20 -0600, Tom Ring
wrote:

Nope, it will be much much less than dipole in almost every direction
except the direction of the wire. There is only so much energy to go
around, and most of it is going in the forward or forward/backward
directions, depending on termination of the wire.

"You cannu break the laws of physics, captain!" - Only a half wave
dipole will act like a half wave dipole.

tom

Hello Major Tom,

Count down, systems on. You haven't modeled have you?

73's
Richard Clark, KB7QHC

Enough so I don't have to model the obvious. I alpha tested 3 different
modeling programs for the author in the early 90's, currently own 5 if I
remember correctly, have modeled hundreds of yagis, built dozens, and
tons of other, non-yagi radiating structures. And designed and built
the highest gain 432 antenna ever tested at Central States VHF
Conference.

If most of the energy is going off the end(s), there can't be much left
to go off the sides, therefore it can't perform like a dipole off the
sides. Those little spikes are very misleading, and very narrow. Apply
an averaging function 2 or 3 degrees wide on the spikes and the nulls,
and you'll see a much truer picture.

The physics doesn't lie - antenna patterns are a have to add up to 100%
of the input power (ignoring losses). If, picking nice round numbers,
90% is in 5 degrees off the end, then only 10% is available for th.

tom
K0TAR

Richard Clark wrote:

On Sat, 27 Mar 2004 21:41:20 -0600, Tom Ring
wrote:


Nope, it will be much much less than dipole in almost every direction
except the direction of the wire. There is only so much energy to go
around, and most of it is going in the forward or forward/backward
directions, depending on termination of the wire.

"You cannu break the laws of physics, captain!" - Only a half wave
dipole will act like a half wave dipole.

tom


Hello Major Tom,

Count down, systems on. You haven't modeled have you?

73's
Richard Clark, KB7QHC

On Sun, 28 Mar 2004 07:38:59 -0600, Tom Ring
wrote:

If most of the energy is going off the end(s), there can't be much left
to go off the sides, therefore it can't perform like a dipole off the
sides. Those little spikes are very misleading, and very narrow. Apply
an averaging function 2 or 3 degrees wide on the spikes and the nulls,
and you'll see a much truer picture.

The program defaulted to 5 degrees which still presented so many lobes
as to be a pin cushion. The net effect is that aside from axial
gain, off side is still pretty much dipole average. No one really
expects those sharp lobes to actually represent reality except if you
were working EME with an apeture that couldn't see ground. Such deep
nulls of only a couple degrees wide only exist in line of sight.

There's a world of difference between modeling antenna characteristics
and propagation reality.


The physics doesn't lie - antenna patterns are a have to add up to 100%
of the input power (ignoring losses). If, picking nice round numbers,
90% is in 5 degrees off the end, then only 10% is available for th.

90% for 10% coverage does not absorb all the gain available; the
multitude of sharp lobes in excess of 2dBi is abundant proof of that.

73's
Richard Clark, KB7QHC

On Sun, 28 Mar 2004 07:38:59 -0600, Tom Ring
wrote:

Enough so I don't have to model the obvious. I alpha tested 3 different
modeling programs for the author in the early 90's, currently own 5 if I
remember correctly, have modeled hundreds of yagis, built dozens, and
tons of other, non-yagi radiating structures. And designed and built
the highest gain 432 antenna ever tested at Central States VHF
Conference.

If most of the energy is going off the end(s), there can't be much left
to go off the sides, therefore it can't perform like a dipole off the
sides.

Suppose you modeled it as a longish dipole? One leg is a quarter wave
at six meters, the other leg is an odd number of 6-meter quarter
waves, stretching out a quarter mile?

Bob
k5qwg

Those little spikes are very misleading, and very narrow. Apply
an averaging function 2 or 3 degrees wide on the spikes and the nulls,
and you'll see a much truer picture.

The physics doesn't lie - antenna patterns are a have to add up to 100%
of the input power (ignoring losses). If, picking nice round numbers,
90% is in 5 degrees off the end, then only 10% is available for th.

tom
K0TAR

Richard Clark wrote:

On Sat, 27 Mar 2004 21:41:20 -0600, Tom Ring
wrote:


Nope, it will be much much less than dipole in almost every direction
except the direction of the wire. There is only so much energy to go
around, and most of it is going in the forward or forward/backward
directions, depending on termination of the wire.

"You cannu break the laws of physics, captain!" - Only a half wave
dipole will act like a half wave dipole.

tom


Hello Major Tom,

Count down, systems on. You haven't modeled have you?

73's
Richard Clark, KB7QHC

Well I had some good typo and editing errors there. But I think the
message was still evident.

Rule #1 - don't edit a message more than once.

tom

Tom Ring wrote:

Enough so I don't have to model the obvious. I alpha tested 3 different
modeling programs for the author in the early 90's, currently own 5 if I
remember correctly, have modeled hundreds of yagis, built dozens, and
tons of other, non-yagi radiating structures. And designed and built
the highest gain 432 antenna ever tested at Central States VHF
Conference.

If most of the energy is going off the end(s), there can't be much left
to go off the sides, therefore it can't perform like a dipole off the
sides. Those little spikes are very misleading, and very narrow. Apply
an averaging function 2 or 3 degrees wide on the spikes and the nulls,
and you'll see a much truer picture.

The physics doesn't lie - antenna patterns are a have to add up to 100%
of the input power (ignoring losses). If, picking nice round numbers,
90% is in 5 degrees off the end, then only 10% is available for th.

tom
K0TAR

Richard Clark wrote:

On Sat, 27 Mar 2004 21:41:20 -0600, Tom Ring
wrote:


Nope, it will be much much less than dipole in almost every direction
except the direction of the wire. There is only so much energy to go
around, and most of it is going in the forward or forward/backward
directions, depending on termination of the wire.

"You cannu break the laws of physics, captain!" - Only a half wave
dipole will act like a half wave dipole.

tom



Hello Major Tom,

Count down, systems on. You haven't modeled have you?

73's
Richard Clark, KB7QHC