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Old September 14th 05, 07:37 PM
Roy Lewallen
 
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Bill Turner wrote:
Roy Lewallen wrote:


An antenna doesn't have a single "radiation angle". It radiates at
all angles. The relevant question is how much does it radiate at the
particular angle of interest, not at which angle does it radiate the
most.


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That's true, except few if any hams have a specific "angle of
interest", since different angles are used at different times. For
most of us, the angle of maximum radiation gives a general indication
of how the antenna will perform. A better indication would be a
graphical representation. It's always a problem when one tries to
reduce a complex situation like this down to a single number.

73, Bill W6WRT


I agree, which is why EZNEC produces a graphical output. I encourage
people to look at it rather than reducing the pattern to a single
number. And I have to emphasize once again that what really counts is
the field strength, not the pattern shape. An antenna can have a
wonderful looking pattern with nearly all its radiation at low angles,
and still be a poor antenna for DX. Or with nearly all its radiation at
high angles and be a poor antenna for short range communications. One
familiar example is a Beverage antenna, which has a lovely pattern shape
but makes a poor transmitting antenna. A quarter wave vertical will
nearly always do much better for transmitting, even at the angles
favored by the Beverage.

Roy Lewallen, W7EL