August 4th, 2009
Most people wonder how come a police vehicle heading towards a crime scene is immediately followed by vehicles of journalist and ambulances. Transmission are eavesdropped by the journalists or anyone else with little eavesdropping device called mobile radio scanner.
A radio scanner is a security device that can be used to monitor multiple discrete signal frequencies automatically. It scans different frequencies and stops when it detects a signal on any one of them. After the transmission stops it begins to scan the other frequencies .This mobile radio scanner or a police scanner is a communication receiver originally intended for monitoring Very high frequency (VHF) ranging from 30 MHZ to 300 MHZ which is used for FM radio broadcast, television broadcast, land mobile stations for the purposes of emergency, military and business , Amateur Radio, marine communications, air traffic control communications and air navigation systems .It can also be used to monitor the frequency immediately above the VHF which is Ultra high frequency.UHF which consists of electromagnetic waves with frequencies ranging from 300 MHZ to 3 GHZ, which is used in public service agencies for two-way radio communication. A mobile radio scanner which monitors the VHF and UHF land mobile radio systems can tune into different kinds of modulation.
Modern mobile radio scanners have advanced microprocessors that can help it to scan hundreds of channels per second and store thousands of channels.
Some of the recent models can follow trunked radio systems and APCO-P25 which is a set of standards for digital radio communications used by federal, state and local public safety agencies in USA to enable them to communicate between them.
A mobile radio scanner is used in emergency services like police and fire services. It also helps in the field of journalism, crime scene investigation, airline services and spying. Many people also use these devices for fun like spying on friends and neighbors to pull off pranks on them. Some of those scanners like BC350C are sold to public commercially. This scanner has facilities like preprogrammed search which can help to find interesting “action band”, search lockout which lets you to shutdown unwanted or uninteresting frequencies and so many other advanced features. Scanners have transformed from an 8 channel crystal controlled devices to handheld and desktop devices which are faster, lighter, cheaper and more advanced than the scanners of the old times.
