> I am just getting into the information gathering mode on this project. For
> several reasons a physically moveable antenna is not desired. I am looking alo
ng
> the lines of changing the phasing feed to two closely placed antenna's to trac
k
> the signal only at receive time.
>
> I don't yet have enough info to get a feel for what is practical and what isn'
t
> - but I do appreciate your input. Thanks.
>
> William Rhoads
>

  Well, if you only have 2 antennas then things kind of change. Take a
look at the directional characteristics of these 2. You will find that
phasing will do you only so much good. In fact, you can get away with only
8 or so fixed positions for phasing, assuming that you can accept a loss
of 3 dB (worst case). Note that this is STILL a gain of 3 dB vs the lone
antenna.

  Those 8 positions make your life much easier, as you can probably use
one receiver and a fixed phaser for a fixed frequency (or band),
controlled by as few as 3 bits from a PIC.

  I believe that some serious work on 2-whip phasing was done for CB and
VHF comms use some time ago, but I can't indicate a book. There must be
something though.

hope this helps,

        Peter