Soliloquy .. .

^ Pittsburgh, my city of residence, has deigned to use the
^ same tone on virtually all their 12 active police channels.

^ Was this very bright for the police radios to have been
^ configured so that the tones are identical on so many
^ frequencies, is there a reason for this?

It isn't un-bright. They probably did it that way out of convenience, or
perhaps through local area coordination. In their application I can't see
that using the same tone on all their frequencies would be a problem. Their
radios aren't designed to receive a wide range of frequencies as your
"wide-range radio receiver" is (I don't like the term scanner), so they
probably don't have the trouble that you are. Their traffic is separated
through frequency channelization so they probably use a CTCSS tone only to
avoid confusion from distant stations on the same frequency and, perhaps, to
make jamming slightly more difficult.

Frank