A scanner is a communication device which is also knows as radio scanner. It is designed to listen various radio transmission signals through radio communication of companies and agencies nearby your area like fire departments, police, government agencies, ambulance services. Scanner is used to scan this various transmission and it’s also can be programmed by frequencies. It will allow you to set a frequencies that you want to receive with bit of set up work and once you done with frequency set up, you can easily listen to frequencies of all the agencies within your country.
There are different types of scanner are available in the market and it can be categorized by its scanning techniques and physical types. There are three types of scanner are available with physical type are mobile scanner, handheld scanner and desktop scanner. The various range is dependent on the antenna which is used.
- Mobile scanner: It is basically used in vehicles which required power source as dc power connection. It use antenna which is vehicle mounted antenna and the main advantage of mobile scanner is optimized for use in various vehicles.
- Handheld scanner: Primary use of handheld scanner is for personal use and for power source it uses battery or ac/dc jack. It has small rubber antenna and the main portability of small size but it has small frequency range which can be categorized into disadvantage of this scanner.
- Desktop scanner: it is for the home usage. It uses ac power connections as power source with the base station antenna. It is optimized for desktop usage.
There are various basic scanning method conventional programmable, crystal controlled and trunk tracking programmable. Scanner have one or more slots for crystal which can help to get single frequency. Then programmable scanner were comes to the market with wide range of capabilities and features too. Police scanner is the device of awareness.