David Hatch wrote:
"art" wrote in 1159495614.320553.169910
@i42g2000cwa.googlegroups.com:


Let us look at a common dipole with a reflector, the planar view of
radiation which ignores radiation outside the plane is a figure 8


For the sake of the arguement, let's say we're feeding the antenna with
100W, so 50W goes one way, and 50W goes the other way. Correct?


where the addition of a reflector does nothing to enhance increased
forward radiation


Now the 50W going towards the reflector... What happens to it? Heat?
Reflected back down the feed line? (Sorry...)


so immidiately we can say that the forward lobe achieves what
is termed a major lobe plus other forward lobes outside of the main
lobe where as the radiation to the rear achieves nothing that enhances
the forward main lobe.


So the most efficient antenna is the isotropic, because its radiating
volume is a sphere. Next would be a dipole, then a vertical, and then
a yagi with just 1 parasitic element, and getting worse as you add
elements, because each element is shaving a bit off the volume.

Correct?

--
David Hatch
KR7DH

It is true that a vertical monopole antenna will have a larger total
footprint of coverage than a yagi. If the earth was evenly coated with
ham radio operators I could probably make more contacts using a
vertical monopole than I could a yagi that could not be rotated.