[R-390] Celebrating Diversity (reception)

[Tom Norris]

>Michael Murphy sez --
>1. Simple Space Diversity - Here we need two identical antennas, that is the
>same polarization, gain, and arrival angle. These could be a couple of
>dipoles at 100 feet. They should be spaced out several wavelenths apart (!!)
>however for diversity to really work.

If you have hundreds of acres, this would work well on AMBC and 160 heehee..

>
>2. Polarization Diversity - This setup purposely uses two different kinds of
>antennas, like what you were suggesting, a Carolina Windom and an inverted
>L. The antennas should not have drastically different gains, or the system
>will not "vote" properly. Better choices might be a Marconi vertical or
>sloper dipole and a regular dipole.

I have used simple crossed dipoles for this. Even when I was trapped in
an apartment, I set up such an "orthogonal" antenna on the balcony. The
R-390A's and the SP-600 for that matter, have sufficient gain to work
with shorter antennas. Orthogonal antennas or loops/vees/dipoles at 90
degrees are a simple solution and work quite well for this. Keeping
up crossed antennas here lately has been a chore with all the recent winds.
I can't tell much difference between my recent "two dipoles on a pole" and
the horizontally mounted very short dipoles that I had at the apartment.
Both work(ed) wonderfully eliminating fade on SW and MW AM signals.

A pair of R-390 or 390a's work for diversity "right out of the box"
simply by tying the diode load and agc lines together and using separate
antennas per the directions in the manual.

Tom NU4G