Tam/WB2TT wrote:
"Antonio Vernucci" wrote in message
...
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If you instead put your receiver/antenna in a point where the two waves
have equal amplitude and same phase, your receiver will measure 200
joules/s (i.e. four times the power produced by each wave alone, not just
two times).

You know that can't be right, because combining two antennas gives 3 db
gain. For example, if you connect them in series, you will get twice the
voltage, but the impedance also doubles.

The constructive interference in free space occurs before
the antennas, not after them. Such is the nature of
constructive interference which very few posters fully
understand. My original posting was designed to expose
the beauty of constructive interference. Instead, I
was accused of diverting the issue or worse.

But it's simply a fact of physics - total constructive
interference between two equal amplitude waves results
in four times the amplitude of each wave. Of course, the
result somewhere else is total destructive interference,
i.e. complete absence of energy.

No one can fully understand what happens at a Z0-match
point without an understanding of interference.
--
73, Cecil http://www.w5dxp.com