Richard Clark wrote:

On 8 Apr 2006 10:28:28 -0700, "Ron J" wrote:


If a
side lobe is a minor lobe, then why is it undesirable to have side lobe
levels less than -20 dB? Thanks!


Hi Ron,

If it were one side lobe, that would be great. If it is several dozen
minor side lobes, then that is entirely another matter. The antenna
design is devoting too much power in this aggregate.

73's
Richard Clark, KB7QHC

As someone who does a lot of V/UHF antenna design, I'd say that -20 is
fine, and less than -20 is generally better if it doesn't screw up the
whole pattern, which it seldom does. The aggregate of a lot of -20 is
an average of less than -20 across the included angles. For EME, which
is pickier than HF, it's fine. I'm not sure what Richard could be
talking about.

Now if you want a 6 meter contest antenna for use in the midwest, you do
not want very low sidelobes, but that's a different story.

Tom
K0TAR