Topband: Diversity receiving

[Larry Higgins]

N0FP asked:
> My question is, how far apart will the 160 antennas have to be to allow
for>
> useful diversity?  I've only got 5 acres so separating more than 500' or
so
> will be difficult.

In Vietnam and Thailand we used three types of diversity for tropo links on
UHF: space, frequency, and polarization.

Space diversity meant two dishes separated by several hundred wavelengths.
Obviously this is out of the question for topband.

Frequency diversity means transmitting and receiving on two frequencies
simultaneously.  The selective fading which can be observed on the AM
broadcast band demonstrates that this would work, but dual  transmitters and
receivers are not likely to appear in many hamshacks very soon. Also,  I'm
not sure the rules would permit it.

Polarization diversity would take very little real estate and should work
very well.

Those who have beverage farms might have further thoughts on space
diversity.

Larry, N9DX