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Telamon · January 20th 07, 03:25 AM posted to rec.radio.shortwave

In article . com,
wrote:

Telamon wrote:

For diversity reception you "switch" to the best signal instead of
mixing them together.

The best approach is two antennas with plus 1 wavelength between
them into two separate receivers and switch the audio between them
based on a decision circuit looking at both radios AGC voltage.

http://www.radioblvd.com/DiversityDD1.html

I find the: "At first the engineers speculated that radio waves were
being refracted in the ionosphere at different angles and therefore
some waves would be intercepted by an antenna while other wave-angles
would miss the antenna. A large multiple antenna should capture more
wave angles and reduce fading. Actually, they found the opposite
happened. Fading became worse with larger antenna arrays. " to agree
with my experience in the much shorter active dipoles (~3' per leg)
worked much better then the 50' wire antennas.

Yes, if you sum the output of several antennas on over the horizon
signals you could end up with greater fading.

One antenna with a greater cross sectional area should have less fading
than say a small amplified antenna.

Diversity reception can also be achieved with two antennas in the same
location with one having vertical and the other horizontal polarization.

--
Telamon
Ventura, California