You place another element closely (behind usually) to the driven element
such that with a
'critical coupling' the feed impedance increases to the desired level.
It is beyond me why antenna manufactures still ask people to match to a low
impedance
which provides losses, when the antenna can be provided with a feed
impedance of 50 Ohm !

I must be in error ofcourse with the above statement as everything is
already known and utilised

May I also point out that if you allow elements to vary in diameter and
height and still keeping to
a .1 boom length, gain increases until ultimately the elements form a
combined parabolic shape
and progressively place rearward radiation energy into the forward direction
until the ultimate is reached,
where there is no radiation to the rear and F/B is absent. I would remind
you that the top element is
going to be designed to be disconnected and connected to ground to
determine impact on static noise.
It is also my intent to string nylon from one end of the elements to the
other, progresively tightening it
until a suitable bend or bow is put in place such that the beam width
narrows to somewhere in the
range of 30 degrees. (ala point to point to get highes gain together with a
lower take off angle)

I do have a fold over tower by the way over 1/2 acre of clear ground with
embedded wire screen
and I am surrouded by sloping farmland with Drummond soil..The 1 inch
hardline is routed undeground.
The above experimentation is why I have so much fun with antenna
experimenting where in other
ways the experts would say it is useless to try before I even put my shoes
on.

Regards
Art


"Chuck" wrote in message
news:w6bfd.12458$6P5.534@okepread02...

wrote in message
news:08_ed.243129$wV.18192@attbi_s54...

"Chuck" wrote in message
news:B3Ted.11167$6P5.7719@okepread02...

...
A 2:1 VSWR bandwidth over the 20m
phone portion implies a good Q, but
aren't you even a bit curious if the gain is
indeed as high as 13 dBi?

Funnily today I changed the model slightly

snipped


I am curious: how are you handling the
driven element's low input impedance?

...
Keep up the fun...


snipped


Hardly

73 de Chuck, WA7RAI