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

Dear Jerry Martes - no call - no location:
EZNEC contains a few files describing simple antennas and good
instructions. You should work through some of those files and
read/study the instruction provided. Prof. Cebik's web site contains
additional instruction and useful observations about antenna modeling
programs. Cebik.Com
As I recall, Prof. Cebik has a book on the subject too.
Jump in. 73 Mac N8TT
P.S. Are you KD6JDJ, who has a name that is similar to yours?
--
J. Mc Laughlin - Michigan USA
Home:


"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

"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

Jerry,

I have a dumb question (maybe). Do you mean two interconnected dipoles, at
the same time, or one dipole at a time?

Tam/WB2TT

J.

Yeah, I renewed my KD6JDJ license. I used to have K6LZC and before that
KL&LL. But, I sure dont know anything about HAM radio any more. I havent
operated a HAM radio in about 30 years.

I've been playing with receiving pictures from the NOAA VHF satellites and
I want to know about antennas for that project.

I heard about the EZNEC program this morning. I seem to have dificulty
learning anything associated with computer programs. But Ill look for the
program on the web tonight and try to make sense of it.

Thanks
Jerry

"J. McLaughlin" wrote in message
...
Dear Jerry Martes - no call - no location:
EZNEC contains a few files describing simple antennas and good
instructions. You should work through some of those files and
read/study the instruction provided. Prof. Cebik's web site contains
additional instruction and useful observations about antenna modeling
programs. Cebik.Com
As I recall, Prof. Cebik has a book on the subject too.
Jump in. 73 Mac N8TT
P.S. Are you KD6JDJ, who has a name that is similar to yours?
--
J. Mc Laughlin - Michigan USA
Home:


"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

Tam

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.

Jerry




"Tam/WB2TT" wrote in message
...

"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

Jerry,

I have a dumb question (maybe). Do you mean two interconnected dipoles, at
the same time, or one dipole at a time?

Tam/WB2TT

Jerry,
You need to learn how to use transmission lines in EZNEC. It will analyze
the whole thing. Post your configuratio: dipole length, height, and
orientation, and how and what kind of transmission line you use for phasing.
I might get a chance to do that, but not in the next 3 - 4 days.

Tam
"Jerry Martes" wrote in message
...

Tam

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.

Jerry




"Tam/WB2TT" wrote in message
...

"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

Jerry,

I have a dumb question (maybe). Do you mean two interconnected dipoles,
at
the same time, or one dipole at a time?

Tam/WB2TT

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.

According to EZNEC, what you are getting now is slightly less
gain than a dipole with a slightly higher take off angle. To
get very good performance out of that configuration, you are
going to have to learn how to phase the inputs different
from in-phase. That means the two elements will have different
feedpoint impedances thus making it difficult to balance the
currents into the elements.
--
73, Cecil http://www.qsl.net/w5dxp



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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

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

Nice. Best response I've seen on a modeling question since I started
watching this group.

tom
K0TAR

Richard Clark wrote:


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.

snip

73's
Richard Clark, KB7QHC