Richard

I dont know how to thank you. I printed the instructions you give in this
thread for me to follow for plotting a pattern from my 137 MH satellite
monitoring antenna. I have been overwhelmed with another program thats too
dificult for me. But, a few minutes ago I began to try to use EZNEC by
following your instructions. Youve presented me with a gift. You have
made this 'plotting' fun. I really appreciate what you've done.
I dont know why I didnt start reading this news group long ago.

Thanks



"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

On Thu, 29 Apr 2004 02:49:24 GMT, "Jerry Martes"
wrote:
Thanks

Hi Jerry,

You are welcome.

73's
Richard Clark, KB7QHC

Jerry-- Arrl prints a book -and has antenna modeling corse-- book is: ARRL
CEP
Antenna Modeling Corse, $ 39.95, plus shipping from Arrl ISBN #
0-87259-872-1
May be overkill, but, might find it interesting-- also available as a .PDF
download from the loeague for their students-- Jim nn7k

--
No trees were killed in the sending of this message. However, a large number
of electrons were terribly inconvenienced !

" People who never get carried away, should be! " --- Malcom Forbes

"Jerry Martes" wrote in message
...
I would like to estimate the radiation pattern from a pair of dipoles.
I've been told that there are computer programs available for drawing
antenna patterns. I's like to try drawing the pattern from my antenna
concept, but would sure like to get some help with learning how to do it
with EZNEC. Is there anyone on this news froup who has time and patience
and who might be willing to E-mail help to me??

Jerry