Uniden BC125AT owner manual What is Searching?, Understanding Scanning, What is CTCSS/DCS?

What is Searching?

The BC125AT can search for active frequencies. This is different from scanning because you are searching for frequencies that have not been programmed into the scanner. When you select frequency bands to search, the scanner searches for any active frequency within the lower and upper limits you specify. When the scanner finds an active frequency, it stops on that frequency as long as the transmission lasts. If you think the frequency is interesting, you can store it into one of the banks. If not, you can continue to search.

Understanding Scanning

What is CTCSS/DCS?

Your scanner can monitor systems using a Continuous Tone Coded Squelch System (CTCSS) and Digital Coded Squelch (DCS) system, which allows the squelch to open only when the tone you have programmed with a specific frequency is received along with a transmission.

CTCSS and DCS are sub-audible tone signaling systems sometimes referred to as PL or DPL (Motorola’s trademarked terms for Private Line and Digital Private Line respectively). CTCSS and DCS are used only for FM signals and are usually associated with both amateur and commercial two-way frequencies. These systems make use of a special sub-audible tone that accompanies a transmitted signal.

CTCSS and DCS are used for many purposes. In many cases, CTCSS and DCS are used to restrict access to a commercial repeater, so that only those units which transmit the correct tone along with their signal can “talk” to the repeater.

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