PMR446 (Private Mobile Radio, 446 MHz) is a licence-exempt service in the UHF radio frequency band and is available for business and personal use in most countries throughout the European Union.[1]
PMR446 is typically used for small-site, same-building and line of sight outdoor activities. Equipment used ranges from consumer-grade to professional quality walkie-talkies (similar to those used for FRS/GMRS in the United States and Canada). Depending on surrounding terrain range can vary from a few hundred metres (in a city) to a few kilometres (flat countryside) to many kilometres from high ground.
Historically, analogue FM is used but a digital voice mode has been available in radios conforming to digital private mobile radio (dPMR446) and digital mobile radio (DMR Tier 1) standards designed by ETSI.
Originally 8 channels were available in analogue mode but this has now been increased to 16 channels. Typically PMR446 is used for both recreational and business use, additionally it has been utilized by amateur-radio operators and radio enthusiasts as a license-free experimental band.
Until recently, PMR446 radios were handheld transceivers with fixed antennas (see Technical information). In November 2015, Midland Radio announced the release of the GB1 mobile PMR446 radio for vehicular use.[2][3][4]
The range of PMR446, just like any VHF or UHF radio, is dependent on many factors like environment (in-city range is far less than in an open field), height above surrounding obstructions, and, to a lesser extent, weather conditions. The antenna type and location, transmit power and receive sensitivity also affect range. However, with PMR446 most of these variables are fixed at manufacturing to comply with the PMR446 specifications. Most of the time the maximum range that a user in a city can expect is a few hundred metres or less.
Range may be many kilometres, for example between hilltops, or only a few hundred metres, if for example a hill or large metal object is in the transmission path between radios. The best known long-distance record is 333 mi (535.8 km) from Blyth in the United Kingdom to Almere, Netherlands.[5] This was the result of enhanced propagation conditions, not a line-of-sight signal.