The Basics

transmissions. In your PRO-97 scanner, the DCS feature can be used to block the reception of transmissions on a shared channel to only those that use the DCS tone that you have specified. DCS mode also features a Code Search setting that allows you to instantly display and store unknown codes into the channel memory. DCS data can sometimes be heard as a low “purring” sound in the background of a voice transmission. Some DCS systems transmit a special “turn off code” at the end of each transmission. The turn off code causes a properly equipped receiver to mute before the transmission ends, eliminating the “squelch tail” burst of noise the commonly occurs when the signal is lost.

Motorola mode

You can set your scanner so it decodes the talk group IDs used with Motorola trunking systems. This setting is called the Motorola mode.

Motorola systems are trunking systems used primarily by business and public safety groups to efficiently allocate a small number of frequencies (as few as five) to many groups of users (as many as several thousand). To do this, each group of users in the system is assigned to a specific talk group. For example, the east side patrol officers might all be assigned to talk group 2160. One channel in the system is continuously transmitting data that identifies which talk groups are active on which channel. In addition, this talk group information is also transmitted as subaudible data on each active channel.

When the scanner receives a transmission on a channel set to the Motorola mode, it first decodes the talk group ID data included with the transmission. In the open mode, the scanner stops on the transmission and displays the talk group ID on the bottom line of the display. In the closed mode, the scanner only stops on the transmission if the talk group ID matches a talk group ID that you have stored in the

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Radio Shack PRO-97 manual Motorola mode