Roy Lewallen wrote:
art wrote:
. . .
Any cursury look at a three D radiation pattern will
immediately see that the main lobe is less than 50 % of the total
radiation pattern . . .

Out of curiosity, did you

a) not read
b) not understand, or snip

I did not understand your logic.
Front to back means nothing in terms of energy containment
The measerment is a ratio not a quantity
It also is a ratio only for a given plane and does not account for
anything outside that plane.
Have I stated anything wrong there?

Point out the error of my ways starting with a simple dipole. Does any
additional element to the array revert the radiation from the rear
direction so that it is additive to the forward directive radiation of
the main lobe? If so what percentage of the rearward radiation in the
rear hemisphere,,(ot a planar amount) ? The question is to you Roy to
answer for a one on one,It would help if you gave an actual percentage
instead of a "major fraction" which you stated before

And if you don't understand then just drop the thread as it has gone
on way to long with relatively little specifics with respect to the
original post
Art








c) not believe

what I posted about the fraction of power in a Yagi's minor lobes?

A cursory look at a 3D pattern is probably one of the least reliable
ways to determine anything quantitative about an antenna pattern. By
choosing the scale (e.g., field strength, power density, linear dB,
ARRL-scale dB), you can make the relative sizes of the lobes just about
anything you'd like and lead the casual observer to the conclusion of
your choice(*). But why bother trying to divine a value from a 3D
pattern, when it's so simple to numerically show that the power in the
lobes is insignificant?



I do not remember seeing any numerical answer ,was it specific and
relative to the
contained energy in the primary lobe because that is what I was looking
for ?
What was the actual percentage that you arrived at?



(*) One of the slides in the "Antenna Basics" talk I've given at many

Roy
the actual scale doesn't matter one iota on a given pattern with
respect to my question !
To compare different patterns one must have a common denominator such
as scale,
to do otherwise is an attempt to deceive. You also use the word
"desirable"and my connoctation of that is a major lobe and nothing else
whereas some may look for other characteristics. Did the group come to
a consensus as to what was desirable? Some may want to hear what is
said behind their backs!


erns, and I ask
the audience which one is the most desirable. After the votes are in, I
reveal that they're all the same antenna, just drawn to different common
and legitimate scales.

Roy Lewallen, W7EL