Mathew--
You seem to have the gist of things.
Yes, each remote receive site is a cross-band "mini-repeater"
complete with controller. Each remote site has a receiver which
listens on the main repeater's 2 meter input frequency and
retransmits the signal back to the main site on 222, 440, 902 MHz,
etc. At the main repeater, a bank of receivers--each tuned to a
specific satellite receive site's particular link frequency--feed
their outputs to the voter. The voter "decides" which signal is the
least noisy and feeds that receiver's audio to the main 2M
transmitter which then does its thing.
Let's consider an example. (Since I don't remember the 902 MHz
bandplan or frequency steps, I'll use UHF freqs. for examples).
Let's say you have a 146.34/.94 repeater with good coverage to the
south and east, but spotty coverage to the north and west. Assuming
you could come up with locations to put up remote receivers, you
could put a 146.34 receiver with a 433.25 MHz transmitter in the
north, and a 146.34 receiver with a 433.75 MHz transmitter in the
west. Back on "Radio Hill" (or wherever the main repeater is
located), you would have two UHF receivers--one tuned to 433.25 and
one on 433.75 MHz--the outputs of which, ALONG WITH THE MAIN 146.34
receiver, would go into the voter. Depending on the quality of the
signal received at any or all or the receiver sites, the voter would
theoretically feed the best to the 146.94 transmitter for all the
world to hear.
The controllers at the remote receiver sites would usually have
their "hang times" set to little or nothing; when the receiver drops
out, the transmitter stops transmitting.
The idea behind using the same equipment at each step of the chain is
a good one when practical, but remember: While excellence is
something to aim for, unless you have extremely deep pockets or
access to a truckload of the same kind of radios (some folks do!),
you may end up with some compromises out of necessity. In my
opinion, it's better to end up with some slight, but tolerable
differences in audio and have a system that does its job, than to
wait for the Motorola truck to break down in your front yard.
On the other hand, with LOTS of police and fire deparments and
businesses leaving UHF in favor of 700, 800, or 900 MHz trunked
systems, you MAY actually be able to create a practically seamless
voting system with a bunch of the same model of radio.
One final thing you may want to consider in using a voted repeater is
to make sure the system is "balanced"--that is, that the transmitter
can be heard where the receivers are listening and vice versa.
Very 73,
Bob
K5IQ
WPXA535
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