wrote:
On 6 Feb 2005 05:42:42 -0800, wrote:


Here is the theoretical H-plane plot of our Yagi:

http://www.drslick.org/Temp1/yagiplot.jpg

And a photo:

http://www.drslick.org/Temp1/yagi929.jpg

After looking at the picture and the plot I fired up yo
and the only way I could get that low a gain was to
seriously mess up the antenna. The end effect was
a 2 element yagi witha spurious useless element.

This is further confirmed by the picture. It appears
the rightmost element is the fed element (very strange for a three
element design) and the proportions suggest a reflector close to the
driven and longer. The third element (the leftmost) would be
spurious
as it's behind the reflector and far away.

Please explain that yagi, it's strange.


It was an unusual use of the YO
program, in that we used two reflectors
and NO directors, to get the shape we
wanted. We actually couldn't use the
optimizer, because it would actually
try to narrow the beam too much.
Remember that you must keep the
pattern about 180 degrees, and the F/B
ratio should be no more than about 11 dB.

If you could come up with something with
a higher overall dBi, i'd like to know,
but i doubt it.


Slick