On 8/14/2011 1:48 PM, Chet wrote:
> A hypothetical question:
Study the fundamentals of antennas, antenna arrays, and fields in the
ARRL Handbook and ARRL Antenna Book. The short answer is that the
signals from multiple antennas will ADD algebraically, taking their
magnitude and phase into account. That is, in some directions they will
be exactly in phase and will be stronger, in other directions they will
be varying degrees of out of phase and either add less, or cancel each
other. if they are equal in level and 180 out of phase, they will cancel
perfectly.
EXACT:LY the same thing happens with reflected signals -- the vertical
patterns of simple dipoles and vertical antennas are the result of
reflections from the earth either adding or cancelling the direct
signal. Ditto for multi-path, and even for much of what we call
selective fading.
73, Jim K9YC
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