Uniden BCT7 English Owners Manual - Page 29

Trunking If your scanner receives strong interference or electrical noise, move the scanner or its antenna away from the source. If you are operating the scanner in a fringe area or need to improve reception, use an optional antenna designed for multi-band coverage. (You can purchase this type of antenna at a local electronics store.) If the plug at the end of the cable does not match the antenna jack, you may need to purchase an adapter. A few state Highway Patrol agencies, and many local and county public safety services, utilize a new type of transmission scheme known as trunking. Trunking allows a number of agencies (such as city police, fire, highway and sewer departments), and/or a number of divisions within an agency (police patrol, detectives, radar teams, warrant servers...), to operate on a single radio system without interference from one another. The agencies may share a three to twenty or more channel radio system in which particular divisions hop about the assigned frequencies as they become available. A dispatcher may be communicating with a precinct's patrol units on 856.7125 one moment, and then receive a reply from a patrol car 30 seconds later on 858.4875. In the meantime, 856.7125 will have been used by two sewer workers. It all happens transparently to the radio users. To them they're the only people using the system and they never have to change channels. To the scanner user, however, it becomes a challenge to follow a conversation. All a scanner user can do is either wait for the radio to resume scanning to the next frequency or use H to move off of an uninteresting conversation. 29