Search results
Results From The WOW.Com Content Network
An Icom IC-R5 hand-held scanner A GMRS radio that also has scanning capabilities. A scanner (also referred to as a radio scanner) is a radio receiver that can automatically tune, or scan, two or more discrete frequencies, stopping when it finds a signal on one of them and then continuing to scan other frequencies when the initial transmission ceases.
Handheld scanner Scanner - a receiver that continuously monitors multiple frequencies or radio channels by stepping through the channels repeatedly, listening briefly to each channel for a transmission. When a transmitter is found the receiver stops at that channel.
Frequency sweeps may be used by regulatory agencies to monitor the radio spectrum, to ensure that users only transmit according to their licenses.The FCC for example controls and monitors the use of the spectrum in the U.S.
The system could cycle through the selected frequencies until stopped. The advantage was that the system could be set up to monitor different sets of frequencies, e.g., police one night, fire departments the next. The first scanner allowing direct entry of decimal frequencies on a keypad, [3] was the Tennelec MCP-1.
In addition to radio frequencies used to connect handsets with cellular base stations, other parts of the radio spectrum are used to interconnect base stations and the wired telephone network. Some frequency bands may be vulnerable to interference by existing services in adjacent frequency bands, such as UHF television broadcasting.
Unlike a conventional radio which assigns users a certain frequency, a trunk system uses a number of frequencies allocated to the entire system. Then the control channel coordinates the system so talkgroups can share these frequencies seamlessly. The purpose is to dramatically increase system capacity with optimal use of frequencies.
(Generally speaking, lower frequencies allow carriers to provide coverage over a larger area, while higher frequencies allow carriers to provide service to more customers in a smaller area.) In the U.S., the analog AMPS standard that used the cellular band (800 MHz) was replaced by a number of digital systems.
Because period is the inverse of frequency, lower tone frequencies can take longer to decode (depends on the decoder design). Receivers in a system using 67.0 Hz can take noticeably longer to decode than ones using 203.5 Hz, and they can take longer than one decoding 250.3 Hz. In some repeater systems, the time lag can be significant. The lower ...