From Phil Stenholm:
Another look back at the History of the Evanston Fire Department.
KSC732 IS ON THE AIR!
In June 1952, the Evanston Fire Department made a major technological leap by purchasing two-way FM radios for $13,000. These radios were installed in all fire stations and most EFD vehicles. The cost was covered by funds from a 1951 bond issue. At first, there were some issues with interference from a local taxi company’s radio signals, but the problem was quickly fixed by engineers from Motorola.
The 20-series numbering system was introduced in 1952 to help avoid confusion with other nearby fire departments that shared the same radio frequency. This was especially important as more departments were expected to join the network. For example, Engine 1 became Engine 21, Truck 2 became Truck 22, and so on. A new pumper/rescue unit was called "Squad 21." Chief Henry Dorband used the call sign "F-1," which he had previously used on the police department's frequency after getting a two-way radio-equipped car in 1951.
The Evanston Fire Department ended up sharing its frequency with several neighboring departments, including Wilmette, Winnetka, Northfield, Glencoe, and Highland Park. Unlike the Chicago Fire Department, which used repeaters on its main frequencies, these suburban departments didn’t have them. As a result, radio transmissions sometimes overlapped, causing occasional interference.
The Evanston Police Department’s base station received the FCC call sign KSA580 in 1951, while the Fire Department got KSC732 in 1952. The station at Fire Station #1 was known as “KSC732 – the desk,†or just “732 – the desk.†Stations #2 through #4 had call signs KSC733, KSC734, and KSC735, respectively. Fire Station #5, which opened in 1955, was assigned KSD841.
The EFD’s radio system was tested twice daily—at 8:00 AM and 8:00 PM. Each station had to confirm it received the test by stating its call sign. If units were out responding to a call, tests could be delayed or even canceled during major incidents.
Company officers were responsible for tracking the status of their fellow units. For instance, the officer of Engine Co. 24 needed to know if Engine Co. 23 was in or out of service, as this could affect response areas. Officers would announce changes over the radio, often using their station’s call sign or just the last three digits.
Initially, both the police and fire radio consoles were located in a room on the second floor of the police station, near the stairs leading to Fire Station #1. Later, they were moved to the first floor, next to the police complaint desk and away from Fire Station #1.
Communication operators were civilian employees supervised by a police sergeant. Their salary was split between the police and fire departments. Before 1975, all operators were men, often retired police or firefighters. They needed strong memory and clear communication skills, but typing wasn’t required.
All fire calls, inhalator calls, and details were broadcast over the EFD radio. Operators announced emergencies like fires, automatic alarms, car fires, and trash fires. Meanwhile, a firefighter at Station #1 typically handled non-emergency calls like lockouts or gas leaks.
A four-second horn alert was sounded before each emergency call or test. This unique tone was activated by pressing a button, similar to a doorbell, and couldn’t be stopped once started. It silenced any ongoing conversations. There were only two buttons—one in the police radio room and one at Fire Station #1’s desk.
Operators didn’t assign units to calls. Instead, they announced the location and type of call twice, then gave the time and the EFD call sign. After that, the radio turned into a conference line. Responding companies had to acknowledge the call, and it was up to the platoon commander to ensure the right units responded.
This old-school dispatch method, which began in 1952, stayed in place until 1982—over 30 years later!
Strontium Chloride,Strontium Chloride Hexahydrate,Strontium Chloride Anhydrous,High Purity Strontium Chloride
Shenzhou Jiaxin Chemical Co.,Ltd , https://www.jiaxinbaso4.com