Uniden BC895XLT English Owners Manual - Page 5

Terminology What is Scanning? Unlike standard AM or FM radio stations, most two-way communications do not transmit continuously. The BC895XLT scans programmed channels until it finds an active frequency. Scanning stops on an active frequency and remains on that channel as long as the transmission continues. When the transmission ends, the scanning cycle resumes until another transmission is received. SCAN 1 CHANNELS 2 3 4 5 6 7 8 9 10 Frequency Frequency not Locked Out entered (L/O) What is Searching? The BC895XLT can search each of its 14 bands to find active frequencies. This is different from scanning because you are searching for frequencies that have not been programmed into your scanner. When you select a frequency band to search, the scanner searches for any active frequency within the lower and upper limits specified. When an active frequency is found, the scanner stops on that frequency as long as the transmission lasts. If the frequency is interesting, you can program it into one of the banks. If not, you can continue your search. What is CTCSS? Continuous Tone Coded Squelch System (CTCSS) is a subaudible tone signaling system sometimes referred to as PL (Motorola's trademark term standing for Private Line). CTCSS is usable only for FM signals and is usually associated with both amateur and commercial two-way repeaters. This system makes use of a special subaudible tone which accompanies a transmitted signal. A set of 38 standard tones has been established by the the Electronics Industry Association. CTCSS is used for many purposes. In many cases, CTCSS is 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." You may also need to have your scanner coded correctly to "hear" the repeater. CTCSS is also used in areas of high interference where there are several stations with output frequencies in close proximity with one another. When this occurs, you may hear multiple communications at the same time. The stations could even interfere with each other to the point where it is impossible to clearly receive either one. When your receiver, in this case a scanner, is equipped for CTCSS, you can code each received frequency with a specific CTCSS frequency. Then, when multiple signals are broadcast, you will only hear the transmission with the CTCSS tone you have programmed. If you do not receive the correct tone with a signal, the squelch of your scanner remains closed and you will not hear anything. Establishment of the CTCSS tone for each transmitter (or repeater) is usually done through the cooperative setting of standards by local frequency allocation groups. 5