On 15 Oct 2006 21:35:43 -0700, "art" wrote:

Yes there is a difference, A yagi is a planar beam ie on a single plane
so the height of the array is the same for all elements in the array
which creates a major lobe or beam.
If the array is not planar such as a Quad then the elements are at
different heights
so the true or effective height of a quad antenna which is also a beam
style antenna is approximately the center point of the array or
somewhere between the top and bottom of the quad element.
The point to stand by is that the height of the feed point is
immaterial with respect to the effective height of an array. In another
post I pointed out that no matter which element is fed in a array the
effective height of the array is always the same and thus the TOA is
always the same
Regards
Art

Hi Art,

One of the most demeaning aspects of this newsgroups concerns misunderstandings
of definitions and terminology that often leasd to unfortunate and unnecessary
arguments.

To wit: Yagi vs beam.

It's been my understanding that any combination of radiating elements intended
to radiate more energy in one direction than omni establishes a major lobe that
is called a beam. In other words, any directional system establishes a beam.
Therefore, 'beam' is generic to all directional radiators.
It then follows that 'Yagi', 'quad', 'W8JK', 'EDZ', are all 'beams' of a
particular type or configuration.

I believe it's important that correct terminology be used for the benefit of the
newcomers--would you not agree?

Walt, W2DU