Hi Reg

I sure dont mean to become involved with the discussion on Cage Dipoles,
and which method of analyzing them, is better.
I do want to give some data concerning the time needed to learn to use
EZNEC. It isnt necessary to devote the time of a 10 day course in order to
be able to get alot of good/valuable data from EZNEC.
At Richard Clark's encouragement, I bought Roy's EZNEC program a couple
weeks ago. I was able to get good data from the program that same day,
The program is not mysterious.
I write this post to make it clear that EZNEC can be learned quickly by
anyone who trys, and can be learned in one day. I dont inply that I am a
well qualified EZNEC operator, but I have learned so much about the antenna
I am investigating that I really treasure this EZNEC program, and recommend
it to any HAM who has interest in understanding antennas.

Jerry





"Reg Edwards" wrote in message
...
Dear Roy,

But the subject matter is Cage Dipoles.

How many man-hours would it take a novice to enter into Eznec, two, in
line with each other, spaced apart, cylindrical cages, 2-feet in
diameter consisting of 32, 14-gauge wires, with 4 end rings, with time
required to diagnose and eliminate the dozen or more bugs which are
sure to be introduced.

That is, of course, if the free version will accept such an input.

We will forget the 10-day induction course.

How long would it take an expert like yourself to enter and fully
analyse such a dipole. Bear in mind you would have to enter dipoles
consisting of 2, 4, 8, 16, 32 and 64 wires, plus end rings, of say 4
different wire gauges. And obtain the resonant frequencies, input
impedances and SWRs of all possible combinations.

You will say Eznec is probably more accurate.

But DIPCAGE2 will do the same job in a few minutes with an accuracy
quite good enough for the intended purpose. CB-ers can use it.

With Eznec, before the job was finished I would have forgotten what it
was all about, strayed off course and ventured into magloops.

To keep you happy, I will repeat what I have said before and say that
Eznec does an excellent job in those tasks for which it is primarily
intended. What better compliment? I am not in competition with you.
----
Reg, G4FGQ.
=======================================

"Roy Lewallen" wrote
This can be done with any EZNEC program type, including the demo:

1. Click Open.
2. Select BYDipole.EZ and click Open in the file selection dialog
box.
3. Click SWR. Enter 14 for the start frequency, 15 for the stop
frequency, and .05 for the frequency step. Click Run.
4. Using the arrow keys or the mouse, move the cursor in the SWR
display
to the points where SWR is about 2. These are about 14.1 and 14.75
MHz,
indicating a 2:1 SWR bandwidth of about 650 kHz.
5. Click Wires in the main window to open the Wires Window.
6. In the Diameter column, change the Diameter from #12 to 6 to
represent a 6 inch diameter cage. (Don't put a "#" in front of the
6.)
Press the Enter key to finalize the change.
7. Click SWR. Change the start frequency from 14 to 13 and click
Run.
8. In the SWR display, move the cursor as before, and note that the
2:1
SWR bandwidth is now about 1.35 MHz, about twice what it was for the
original antenna made from #12 wire.

Now you're a Reg-certified expert, even if that took you a month of
Sundays to do.

You can also get a great deal of additional information from EZNEC,
such
as the feedpoint impedance and SWR at any frequency, the pattern,
and
effect of height and ground characteristics.

If that took you a month of Sundays, you might think a bit about
what's
reduced your capabilities to that level.

Roy Lewallen, W7EL
-- Certified by Reg as both Old Wife and Expert!

Reg Edwards wrote:
It takes a month of Sundays for an expert to enter and interpret
the
input/output data of a cage dipole using an Eznec-type program.
. . .