The Family Radio Service (FRS) is an improved walkie-talkie radio system authorized in the United States since 1996. This personal radio service uses channelized frequencies around 462 and 467 MHz in the ultra high frequency (UHF) band. It does not suffer the interference effects found on citizens' band (CB) at 27 MHz.
Initially proposed by RadioShack in 1994 for use by families, FRS has also seen significant adoption by business interests, as an unlicensed, low-cost alternative to the business band.
Family Radio Service, FRS basics
FRS is a licence free radio system. The radios use narrow-band frequency modulation, NBFM, with a maximum deviation of 2.5 kHz. The power is limited to 500mW by the U.S. Federal Communications Commission (FCC) regulations.
The provisions of the FRS service allow for the use of sub-audible tones including CTCSS and DCS. This enables the squelch of the radio to be only opened by users with the correct tones and in this way preventing unwanted noise.
All equipment used on FRS must be type accepted according to FCC regulations. To meet these requirements the equipment must be limited to 500mW and the antenna must not be detachable. However there are FRS "base station" radios that have whip antennas. The power and antenna limitations ensure that the range is limited and interference between users is reduced to acceptable levels.
A further restriction is that the use of duplex radio repeaters and interconnection to the telephone network are prohibited.
Family Radio Service, FRS frequencies and channels
FRS uses a total of fourteen channels spaced at 25 kilohertz intervals, with all frequencies ending in 2.5 or 7.5 kHz.
The number of frequencies or channels available allows users to select one of a variety of channels and in this way avoid interference.
Channels 1 to 7 are shared with the GMRS system and often communication may be established between them. If the permitted FRS power limit is exceeded on these channels then a GMRS licence is required.
|FRS Channel Allocations|
|FRS Channel||FRS Frequency (MHz)|
Note: Channels 1 to 7 are shared with GMRS operation, but channels 8 to 14 are reserved for FRS use only.
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