When I setup an antenna in EZNEC, I want to see the azimuth but the
program asks for an elevation angle. WHat angle should I use? I have
been randomly using 5 or 10 deg.

Thanks


--
73 for now
Buck
N4PGW

Buck wrote:
When I setup an antenna in EZNEC, I want to see the azimuth but the
program asks for an elevation angle. WHat angle should I use? I have
been randomly using 5 or 10 deg.

Thanks


--
73 for now
Buck
N4PGW

Hi Buck, Antennas have a 3-dimensional pattern. When you only want
to see the Azimuth, you are looking at a 2D pattern, with a fixed
elevation angle. The Azimuth plot must have an elevation angle to have
meaning. The elevation angle you use depends on a number of factors.
For instance, if you want to work dx, or want to hit a distant
repeater, you want the most gain at low elevation angles. You want the
Azimuth pattern to show the most gain at low elevation angles. I think
5-10 degrees qualifies as low angles.
EZNEC shows on the elevation plot the angle where the gain is
maximum. It also has a 3D plot that really gives a good indication of
where you are squirting the most signal.
Gary N4AST

On 15 Jun 2005 14:51:19 -0700, wrote:



Buck wrote:
When I setup an antenna in EZNEC, I want to see the azimuth but the
program asks for an elevation angle. WHat angle should I use? I have
been randomly using 5 or 10 deg.

Thanks


--
73 for now
Buck
N4PGW

Hi Buck, Antennas have a 3-dimensional pattern. When you only want
to see the Azimuth, you are looking at a 2D pattern, with a fixed
elevation angle. The Azimuth plot must have an elevation angle to have
meaning. The elevation angle you use depends on a number of factors.
For instance, if you want to work dx, or want to hit a distant
repeater, you want the most gain at low elevation angles. You want the
Azimuth pattern to show the most gain at low elevation angles. I think
5-10 degrees qualifies as low angles.
EZNEC shows on the elevation plot the angle where the gain is
maximum. It also has a 3D plot that really gives a good indication of
where you are squirting the most signal.
Gary N4AST


Thank you Gary, I have been looking at it a bit. I decided the best
way to get an accurate reading for the highest gain is to look at the
elevation and then set the azimuth elevation to the TOA.

Thank you,

Buck
N4PGW

--
73 for now
Buck
N4PGW

Buck wrote:
. . .
Thank you Gary, I have been looking at it a bit. I decided the best
way to get an accurate reading for the highest gain is to look at the
elevation and then set the azimuth elevation to the TOA.

But what you're probably really interested in is the gain in the angle
you'll be using for communication. Who cares what the maximum gain of
the antenna is if that gain only occurs in directions (azimuth or
elevation) you're not using for communication?

First, decide what elevation angles will be used for communication. One
way to find that is by using a propagation program like W6ELProp (which
is free). Look at the gain at those angles with EZNEC. The elevation
angle at which the gain is maximum is of very little practical use --
EZNEC reports it only because a lot of people wanted it (for reasons
which remain mysterious to me).

Roy Lewallen, W7EL

On Wed, 15 Jun 2005 16:19:58 -0700, Roy Lewallen
wrote:

Tsk tsk.


EZNEC reports it only because a lot of people wanted it (for reasons
which remain mysterious to me).

Don't you know that the customer is always right? [grin]

The elevation
angle at which the gain is maximum is of very little practical
use --
EZNEC reports it only because a lot of people wanted it (for reasons
which remain mysterious to me).

Roy Lewallen, W7EL

===========================

Roy, good to see, at last, you've got rid of this popular
misconception.
----
Reg.

Wouldn't this 'gain' be useful in figuring out just where you could dump
your maximum signal somewhere in the world? It might not be where you
want, but at least you might have an idea of where you would stick a loud
signal using max gain at some elevation angle? Or is this a totally useless
idea? I don't pretend to know what I'm talking about here, but it seems
logical that by using this type of data it would help you figure out where
you were going to put in a stronger signal.

Shields up!

Jer

"Reg Edwards" wrote in message
...
The elevation
angle at which the gain is maximum is of very little practical
use --
EZNEC reports it only because a lot of people wanted it (for reasons
which remain mysterious to me).

Roy Lewallen, W7EL

===========================

Roy, good to see, at last, you've got rid of this popular
misconception.
----
Reg.

Roy Lewallen wrote:

The elevation
angle at which the gain is maximum is of very little practical use --
EZNEC reports it only because a lot of people wanted it (for reasons
which remain mysterious to me).

Maybe the guys out at Goldstone can explain it.

:-)
ac6xg

On Wed, 15 Jun 2005 16:27:55 -0400, Buck wrote:

When I setup an antenna in EZNEC, I want to see the azimuth but the
program asks for an elevation angle. WHat angle should I use? I have
been randomly using 5 or 10 deg.

Depends. If you want to see the whole picture, use a 3D plot.

You should know that you can grab this with the mouse and change the
angle of view. By turning on the "Highlights" you can get any cut you
want on the pattern. Experiment.

For a feature rich (and free) alternative that will give you these
plots in living color see:

http://www.si-list.org/swindex2.html#4nec2_

That said, and not taking anything away from Arie's masterful work, I
recommend that you stick with EZNEC until you are more skilled at
modeling.

Buck wrote:
When I setup an antenna in EZNEC, I want to see the azimuth but the
program asks for an elevation angle. WHat angle should I use? I have
been randomly using 5 or 10 deg.


An example of an approach to antenna design that starts with
identification of the paths to be optimised is at
http://www.vk1od.net/7MDipole/7MDipole.htm .

In this case, I was interested in local contacts and over 50% of
Australia's population was located in just four cities at distances up
to 1000Km. The propagation paths to those locations was modeled to
provide the geometry for assessment of antennas in EzNEC.

BTW, 5 to 10 degrees elevation is probably below most propagation paths
for DX, let alone local contacts. Lowest angle doesn't necessarily
translate to optimal for distant stations (it depends on the propagation
mechanism at the time), and the most desirable DX might not be at the
greatest distance. Best performance at low angles might assure maximum
pickup of local noise sources, and in my case QRM because I am not at
all interested in DX.


Owen