When you are searching for a handheld radio scanner, you will find many different choices, including a digital radio scanner. Here are some basics that will help you decide if one of this type is right for you.
A radio scanner, or police scanner as it is often called, is a receiver that can be used to monitor VHF and UHF radio systems. Any type of information transmitted by two way radio can be heard with these scanners. Most offer a feature that can be set to ignore or accept transmissions from specified departments.
In the past, scanners could only monitor a few different channels. Depending on which you select, a mobile radio scanner is now capable of monitoring hundreds of channels between 30Mhz and 3Ghz. The VHF to UHF is between 300Mhz and 3Ghz and is used by public service agencies with their two-way radios.
Very high frequency (VHF), ranging from 30 MHZ to 300 MHZ, is used for FM radio broadcast, television broadcast, land mobile stations for emergency purposes, military, business, amateur radio, marine communications, air traffic control communications, and air navigation systems.
Other than being used in law enforcement agencies, police scanners are also used for high frequency communication in corporations and in emergency services to keep their information private.
Because of the rise in the number of intrusions taking place in their communication devices the corporations began to broadcast digitally. This move opened up the market for digital scanners as technology kept pace with the advances made by the corporations.
A digital radio scanner is the latest version of popular scanners. They are designed to receive and process digitally encoded signals transmitted between various two-way radio systems in public use.
The reason these scanners are called “digital” is because they are designed to be compatible with radio signals transmitted in digital mode rather than the conventional analog mode, although older analog signals and newer digital transmissions are both in use. Most of the digital scanners will still process the analog signals too.
Digital signals are less affected by interference and noise, and deliver usable information better at the extremes of their range when analog signals become unpredictable. Some digitals also come equipped with the trunk tracking feature to make use of trunk lines. Most police and fire departments use radio frequencies and channels that are tied together through a trunk system.
When you are looking at a handheld radio scanner, more than likely you will come across the phrase APCO P-25. This is a set of standards for digital radio communications used by the federal, state and local public safety agencies in USA for communication between them. Non-encrypted digital signals meeting the APCO P-25 standard can be processed by digital radio scanners.