My first true scanner was an eight channel scanner like the one pictured in Chief21's post, installed in my POV using a cut down CB antenna, when I was a volunteer fireman in the 70s. I also had it tapped into my siren PA which came in handy at scenes, before we had pagers and portable radios. I believe it was Lo Band only, but most stuff was low band back then. At times it received better than the Motorolas in the PD and FD vehicles. In 1978 when I got into law enforcement we ended up installing these in the cruisers and using them for agency-to-agency comms by listening to each others frequencies and we were able to talk two-way, sort of a duplex system. This was before interop channels. I also had the fire dispatch channel in there to keep ahead of things.