"Wes Stewart" wrote in message
...
On Thu, 17 Mar 2005 10:54:50 -0800, Roy Lewallen
wrote:

Actually, it is possible to lower the takeoff angle (the elevation angle
at which the pattern is maximum) without changing the antenna height.
The method is to narrow the free-space elevation radiation pattern. For
example, modify the EZNEC example file W8JK.ez by changing the height (Z
coordinates) to 0.5 wavelength. The takeoff angle is 25 degrees. Delete
one of the elements to make a dipole and note that the dipole's takeoff
angle is 28 degrees. The lowering is due to the substantially greater
elevation directivity of the W8JK. There aren't too many modestly sized
horizontal arrays that have enough elevation directivity to make much of
a difference in takeoff angle, however, so the difference is generally
small at best. It's also interesting to note that the takeoff angle of
this dipole over real ground is 2 degrees lower than the takeoff angle
of the dipole over perfect ground.

All true. I see my response was too encompassing. What I was trying
to refer to was Art's "magic" design.

To wit: "Would hams have an interest in a two element 20 M antenna
that have (sic) lower TOA than the norm, say 9 degrees instead of the
normal 14 degrees?"

I can't imagine anything that will make a 2 (or any other number)top hat
element horizontal antenna of any configuration have a TOA of 9
degrees other than placing the array center at a height of ~105' above
real ground at 14 MHz.



I don't remember the two element bit and I also stated it was NOT a yagi
design.
You mentioned horiuzontal antenna which suggests a yagi design unless you
intended
horizontal "polarisation". Roy, same as I, is pointing out the number of
incorrect statements that you have made and you are now adding to them.
To help you out I will stop posting on this thread to save you any further
embarrasment, that way you will not need to admit to anymore errors.
Pity you didn't define what you meant with respect to antenna height i.e.
feed point height, top hat height, a higher unfed antenna height and so on.
Adding ambiguety just leads to confusion for everybody.
Frankly you are looking more like Richard every day with your leaning on
emotions instead instead of technical matters pertaining to the thread with
the
assumption that all must be placed before you for judgement as you are the
leading analysts in antenna design.
Actually with respect to this thread both of you are showing that you are
wearing no clothes tho Richard could well be wearing Shakespeare hose
of a see thru nature that he wears around his abode.
See you on another thread perhaps.
Regards
Art KB9MZ....XG