Chicago Police Radio System Brochure - circa 1977

[zerg901]

chicago_pd_comm1970sbrochure.pdf

approx 10 page brochure with text and photographs

my apologies if this has been posted before

 

[werinshades]

I took a school field trip to 11th State when I was in grammar school. We went to the 2nd floor communications section observation window and I just stood there and didn't want to leave.

 

[N9JIG]

My Dad was the Illinois Bell project manager for the CPD system in the 60's and 70's and worked with the CPD staff to coordinate the redrawing of CPD Districts to match phone exchange boundaries. This helped easily route phone calls to the proper Zone operator in the days before electronic switching systems in phone exchanges.

Later on when I started as a dispatcher for a suburban PD there also used to be special telco numbers (the exchange followed by a common 4 digit number) to call the Zone operator directly. I doubt they still work some 40 years later but with Chicago you never know...

 

[werinshades]

My Dad was the Illinois Bell project manager for the CPD system in the 60's and 70's and worked with the CPD staff to coordinate the redrawing of CPD Districts to match phone exchange boundaries. This helped easily route phone calls to the proper Zone operator in the days before electronic switching systems in phone exchanges.

Later on when I started as a dispatcher for a suburban PD there also used to be special telco numbers (the exchange followed by a common 4 digit number) to call the Zone operator directly. I doubt they still work some 40 years later but with Chicago you never know...

(312) 746-xxxx ? Those have been around a long time, but not sure if those are the numbers you mentioned.

 

[N9JIG]

No, each Zone had a different exchange and the last 4 digits were the same citywide. The exchange prefix was from the host exchange for that Zone.

This was separate from the city 746 exchange.