http://webapps.sfm.illinois.gov/FireDeptSearch/
http://www.illinoisfiretrucks.com/ILLINOIS-FIRE-DEPARTMENTS-BY - listed by county - (except you have to go here https://www.illinoisfiretrucks.com/ to see Cook County etc)
The "Drill & Photo" group at YahooGroups had lots of photos of Chicago area fire departments - around 2010 2011 the group was very active - 10/7/2019
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1949 radio info for Chicago Police - WPDB - 1714 kc AM - WPDC - 35.22 Mhz FM - 201 mobiles - WPDD - 1714 kc AM - WQJF - 31.10 Mhz AM - 103 mobiles
1949 - no radio listing for Chicago FD
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1969 area info for Chicago area - from CRB Directories in Radio Experimenter Magazine
most agencies were on VHF highband - between 153 Mhz and 160 mhz
Chicago FD - KSC711 - 153.77 - 154.13 - 154.22
Chicago PD - Citywide 1 - 453.50 - Citywide 2 - 453.45 - also - 155.37 (mutual aid) - 158.85 - 159.15 - 453.80 - 453.60 - 453.30 - 453.35 - 453.40 - 453.90 - 453.20 - 453.10 - 453.25 - 453.75
US Coast Guard - 41.22
Civil Air Patrol - 143.90 - 148.15
Chicago Transit - 44.54
Chicago City Forestry - 159.45
DuPage County - forestry - 31.86 - (maybe park rangers)
Illinois State Police - 39.46 - 42.50 - 42.52 - 42.56 - 42.60 - 154.68 - 154.92 - Narcotics - mobiles - 39.06 - 154.71 - Public welfare police - mobiles - 155.43
Indiana State Police - 42.42
Indiana Toll Road Commission - 154.755 - 155.415 - 156.03