Conventional Radio Systems

There are 2 methods of organizing frequency/channel usage in a radio system: "Conventional" and "Trunked" radio systems. In a "Conventional" radio system, different users or groups of users are grouped onto separate channels or frequencies. For example, the Police Department may have 8 channels, organized in the following way:

	Police Department Channels
Channel 1.  460.025 MHz - Police Dispatch
Channel 2.  460.075 MHz - Eastside Road Patrol Unit
Channel 3.  460.125 MHz - Westside Road Patrol Unit
Channel 4.  460.150 MHz - Northside Road Patrol Unit
Channel 5.  460.175 MHz - Southside Road Patrol Unit
Channel 6.  460.200 MHz - Detectives
Channel 7.  460.225 MHz - Special Operations
Channel 8.  460.275 MHz - Car-to-Car

In this system, police officers may normally listen to the Police Dispatcher on channel 1 which is on 460.025 MHz. This frequency is known as Channel 1 and is dedicated solely for this purpose. Similarly, Channel 2, 460.075 MHz, is dedicated solely for use by communications to or from members of the Eastside Road Patrol Unit. Each frequency is dedicated to one group of users. If another unit needs to talk to a particular group, they simply transmit and receive on the channel/frequency reserved for that group. Since officers in each group transmit on a different frequency, officers in 2 or more groups may transmit messages to other officers in their respective groups without causing interference. An officer who is part of the Eastside Road Patrol could transmit to other officers in his group on Channel 2. At the same time, another officer who is part of the Westside Road Patrol Unit could transmit to other officers in his group on Channel 3 without causing interference to the group on Channel 2.

A radio scanner listener will typically set his or her radio to scan all channels for activity. If he or she wishes to focus on what group, he will simply have the scanner wait on the desired channel/frequency. These "Conventional" radio systems may be easily monitored on virtually any radio scanner that receives the correct frequency.

For analog conventional systems on any frequency band other than 800 MHz (i.e. 30-50, 150-162, or 450-470 MHz), scanners in any category will work, with radios in Category 1: Budget Scanners and Category 2: Conventional Scanners without 800 MHz being the least expensive. Scanners in Category 2 or higher are recommended if you wish to monitor more than one department or plan to use a search mode. If one or more of the departments use the 800 MHz radio band (i.e. frequencies between 851-869 MHz), you will need a radio in Categories 3, 4, 5, or 6, with Category 3 radios usually being the least expensive.

Part 3A: Land Mobile Radio Systems

Skip Ahead to Part 4: Table of Listening Topics and Scanner Categories

Trunked Radio Systems

Radio Scanner Guide

Conventional Radio Systems