Thanks Richard

I printed your post. I'll try to learn how to use that antenna modeling
program. I am amazed at how engineers have gotten so smart these past few
years. It seems impossible that anyone could get smart enough to do
something this complex that it models antenna patterns almost immediately.

It will sure be satisfying to become able to use this program.

Jerry




"Richard Clark" wrote in message
...
On Tue, 27 Apr 2004 05:53:19 GMT, "Jerry Martes"
wrote:
I have the two dipoles fed in phase and spaced 1/4 wave apart The
anrenna
really works well. I'd like to try to improve it but first need to know
more about what I'm getting now.

Hi Jerry,

Well, I presume you've corresponded here enough to recognize the
answers to questions fit what the respondent chooses.

Open EZNEC;
Select the "Open" button that is at the top left of the application;
Select the W8JK.EZ design offered;
From the string of "" selections, choose "Plot Type";
then select "3 Dimensional" - "OK" (and respond "OK" again to prompt);
Finally select the "FF Plot" button at the bottom left.

This will generate an X-Y-Z plot of the radiation lobes of this
particular antenna design. Clicking and scrolling your mouse over the
image will roll and rotate it to allow you to shift perspective. The
antenna element spacing is closer than your quarter wave (0.1 in
fact), but it gives you a basis to change things and see what happens.

This means you can introduce your self to the Wires table (select the
"" which is labeled "Wires"). Change something and then look at the
antenna (select the Button labeled "View Ant"). To see how your
change impacts transmission lobes, select that same button "FF Plot."
The Wires table is based on simple XYZ co-ordinates for each end of a
wire (segments is an artifice of necessity for the computation engine,
once you've laid out the basic form, we can come back to that later).

Instead of worrying about clunky transmission lines, you simply
replace them with "Sources" that take their place (this antenna has
two of them to represent the split feed). You can be anal and build
them out of virtual transmission lines, but give yourself a break and
ignore that; it is hardly instructive for the first pass.

Welcome to the world of modeling. Press more buttons and appreciate
the scope of data available for analysis. Return to the "Open"
button, and appreciate the variety of simple designs that offer a
fairly broad selection of styles. The free version allows quite a
latitude of variation, enough to educate you in all the fundamentals
of both design and the application.

73's
Richard Clark, KB7QHC