Uniden BC125AT owner manual Conventional Scanning

CTCSS and DCS are also used in areas that receive interference where there are several stations with output frequencies close to each other. When this occurs, you might hear multiple communications on the same frequency. The stations might even interfere with each other to the point where it is impossible to clearly receive any of the stations. Your scanner can code each received frequency with a specific sub-audible CTCSS or DCS frequency or code. Then, when you receive multiple signals, you only hear the transmission with the CTCSS or DCS tone you programmed. If you do not receive the correct tone with a signal, the scanner’s squelch remains closed and you hear nothing.

Refer to the Reference section of this manual for tables showing the available CTCSS frequencies and DCS codes.

Conventional Scanning

Conventional scanning is a relatively simple concept. Each group of users in a conventional system is assigned a single frequency (for simplex systems) or two frequencies (for repeater systems). Any time one of them transmits, their transmission always goes out on the same frequency. Up until the late 1980’s this was the primary way that radio systems operated.

Even today, there are many 2-way radio users who operate using a conventional system:

•Aircraft

•Amateur radio

•FRS/GMRS users

•Many business radio users

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