If you've ever wondered just exactly what the police and fire departments in your area are up to, you can use a device called a scanner to find out. A scanner listens in on certain frequencies that police and fire departments use, and lets you hear the action in real time. However, each department broadcasts on a different frequency in order to avoid conflict between other divisions or radio users, and frequencies vary from area to area.
Use the preassigned bands that come with your scanner. Most scanners come with bands pre-made that include popular frequency ranges for police and fire radio. You can access these bands by pressing the "band" or "mode" button on your scanner.
Browse the National Radio Data's frequency list (see Resources). The National Radio Data site is a directory containing thousands of different police and fire codes, and includes the frequencies for most state police departments and major cities such as San Francisco, Los Angeles and Boston.
Search for your police and fire frequencies at The Police Scanner Info site (see Resources). The Police Scanner Info site offers frequencies to different departments in most states via an online directory. Frequencies are in categories such as police, fire, airport and harbor/forest ranger where applicable.