Uniden BCD260DN English Owners Manual - Page 13

What Is Scanning?

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WHAT IS SCANNING? Unlike standard AM or FM radio stations, most two-way communications do not transmit continuously. Your BCD260DN scans programmed channels until it finds an active frequency, then stops on that frequency and remains on that channel as long as the transmission continues. When the transmission ends, the scanning cycle resumes until the scanner receives another transmission. WHAT IS SCANNING? The BCD260DN 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 for 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 a Digital Coded Squelch (DCS) system, which allow 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. 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. 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 Appendix A for tables showing the available CTCSS frequencies and DCS codes. 13

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13
WHAT IS SCANNING?
Unlike standard AM or FM radio stations, most two-way communications do
not transmit continuously. Your BCD260DN scans programmed channels until
it finds an active frequency, then stops on that frequency and remains on that
channel as long as the transmission continues. When the transmission ends,
the scanning cycle resumes until the scanner receives another transmission.
WHAT IS SCANNING?
The BCD260DN 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 for 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 a Digital Coded Squelch (DCS) system, which allow
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.
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. 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 Appendix A for tables showing the available CTCSS frequencies and
DCS codes.