Some useful channels to program into a police scanner are those for fire departments, emergency medical service providers, public works departments and state or county departments of transportation, suggests Scanner Master. Police departments often communicate with these agencies in the course of investigating incidents and responding to calls.
A police scanner also should include radio frequencies for sub-channels devoted to the traffic of district patrols, fire dispatch, fire administration, parks or traffic signals of larger public safety departments, according to Scanner Master. In a large metropolitan area, people operating home scanners may want to program radio channels for nearby public safety agencies that participate in mutual aid agreements with surrounding police and fire departments.
Other useful channels include those that monitor two-way traffic for taxi companies, airports, mall security, railroads and colleges, Scanner Master states.
Typical home scanners pick up transmissions within a 10- to 20-mile radius, reports Scanner Master. Scanner manufacturers, including Scanner Master, sometimes provide frequency guides so owners can program their scanners to local channels. National Radio Data offers an online searchable database of national scanner frequencies, notes the company website.
News reporters, radio hobbyists and neighborhood safety advocates are among those who listen to police scanners, states Scanner Master.