have you tried this???
http://www.google.com/search?hl=en&q...ch+yagi+design
lots of sources for design info, some software, plenty of pointers.
basically once you have a yagi and decide to feed it with a gamma match you
have the following variables you can work with (assuming you aren't going
to change the diameter of the driven element)...
1. rod diameter
2. rod to driven element spacing
3. location of shorting strap
4. value of capacitance
5. length of driven element(don't forget this, it is very important part of
adjustment!)

now basically you pick a rod diameter, usually 1/3 to 1/2 the diameter of
the driven element, but basically whatever you happen to have handy that is
a reasonable length. then make a few brackets to space it a couple inches
from the driven element, from about 1" on 2m to maybe 4-5" on 20m. so that
fixes 1 and 2.. then you have 3 other variables you can adjust to get the
match you want. if you can't find a good match after systematically running
through the other 3 then try changing the spacing a bit and start again...
but i've always been able to get a decent match by just picking what was
handy for tubing and spacers.

and don't overlook a T match. if you use a 1/2 wave phasing line and the
right diameters and spacing you can get away without a capacitor. this
makes for a fully dc grounded plumbers delight construction that is very
rugged and simple to adjust. this was how all the old telrex monobanders
were fed.



"Jim Kelley" wrote in message
...


John Smith wrote:

Cecil:
Yes Cecil, there is wisdom in your words...
However, as I pointed out, I am now focusing on "received signal", its'
quality and strength.
After having given it some thought, that is what is most important. In
an
grave emergency I have the ability to bring multiple kilowatts on line
(yes,
I have the generator to support it.) What I can't do is guarantee that
for
the fellow at the other end of the contact. So, I am focusing my
attention
towards his/her benefit--in the refinement of my ability to pull
sub-nano-watts from the ether...
EZNEC and all other calculations are great, I appreciate what can get me
to
ballpark figures with matching, lengths, spacings, predictions, etc.
But, in the end, the humble s-meter on a known transceiver, compared
against
know signals and similar conditions will be my final guide and the
determining factor.

I think you'll eventually end up finding out you just need a big tower
and a big beam.

ac6xg