I first got into the fire service on long island in 1979. i was hired as a full time dispatcher by my volunteer department-(good because i had a job-bad because i missed some calls). we had a trunking telephone system between our 5 firehouses and if i knew anyone was hanging out there and they got a call, i would give a single long ring for an ambulance call and a series of short rings for fires. during meetings i would ring the company who's zone it was in as soon as i had the address. it was kind of cool that i would ring my firehouse first then everyone could head to the trucks and come up on the radio as soon as i put it out on the air before anyone else

It backfired on me only once

I was chatting with my LT who lived down the street from my captain when we got a structure fire in my co's zone. he blew past my captain's house blue lights balzing just as i was putting it out (the captain wondered what was going on-he was washing his car at the time and he lat me know about it later).

The broad soultion was i would "dead key" the mike (send a series of clicks over the dispatch frequency) however many times for whatever company was getting a call.

We also had a ringdown phone between our nearest departments, if they had a worker that i could see, i'd pass it on and they did the same which was good because it allowed us to get a handle on greater alarms and better coordinate mutual aid

Having a CB radio was cool because if somebody saw a fire before i dispatched it the additional info helped.

While in college i dispatched for a two station vollie dept that had 5 alerting sirens. i loved opening the window  when i set them off, the sound was awesome!!!