"John E. Davis" wrote in message
...
Hi,

I created a "omni-directional" vertical antenna that NEC-2 reports to
have a free-space gain 4 dBi. The shape of the antenna looks like:


------+
A |
| B
|
+-----+
C * (* = feed point)
+-----+
|
|
|
------+

The lengths can be adjusted to give the antenna a 50 ohm feedpoint
impedence. The overall length of wire forming the antenna (4A+2B+C)
is on the order of 1.5\lambda and the height (2B) is something like
\lambda. I built this antenna for 2-meters and it seems to perform
quite well. The .nec files and parameters are available from my
antenna pages at http://www.jedsoft.org/fun/antennas/omni.html.

I am sure that I am not the first to create this simple antenna,
nevertheless a google search has turned up nothing similar. Have you
seen such an antenna before and if so, what is it called? I suspect
that it belongs to some class of antennas (antennae?). I would
like to give the proper credit and name for it on my web page.

Also, if you can find a flaw in my NEC modeling of the antenna, please
tell me. The prototype that I built does have an SWR of 1.05:1 as
given by my uncalibrated meter at the design frequency.

Thanks,
--John

Hi John

I really got interested in the configuration you show for the antenna.
But, when I looked more closely to the Elevation Plane Pattern that looks so
narrow (high gain), I realized that the antenna is very much the same
pattern as a basic full wave center fed wire.
The graduations on the plot graph was misleading to me.
Perhaps there is something special about this antenna that I am missing.

Jerry