The USA's Federal Communications Commission created MURS in Fall 2000. MURS, or the Multiple Use Radio Service, is a license-free service for two-way radio communications, similar to FRS. MURS uses some frequencies previously allocated for business use, which required licensing.
MURS uses these frequencies:
- 11.25 kHz bandwidth: 151.820, 151.880, 151.940 Mhz.
- 20.0 kHz bandwidth: 154.570, 154.600 Mhz.
MURS may be used to transmit voice or data, including data for remote control or telemetry operations.
According to FCC part 95, interconnection to the telephone network and repeater stations are prohibited. Transmitter power is limited to 2 watts PEP. This means your transmitter can put out 2 watts, but antenna gain is not limited. Your antenna does, however, have to be no more than 60 feet above the ground, or 20 feet above the highest point of the structure on which it is mounted. This limitation is intended to limit MURS frequencies to local use.
Equipment for MURS is, at the moment, somewhat limited. Radios manufactured after November 2000 are to meet certain design criteria for use with MURS, including that they are not to be capable of being set to operate on other frequencies. Older equipment built for use with the VHF business band, which was certified for use on (and can be programmed to) the MURS frequencies is also allowed, as long as the transmitter power is 2 watts or less. Although I do not know of any radios manufactured exclusively for MURS use (send me a /msg if you know of any!), fairly inexpensive business band equipment that can be programmed for MURS is fairly easy to find. One such radio is the Radio Shack BTX-127.
Why would you want to use MURS? Here are some reasons:
- Long range: Using directional and/or high-gain antennas, you can communicate over longer distances than you can using FRS, which requires .5 watt radios with nonremovable antennas and no antenna gain.
- Multiple modes: Voice and data transmissions are allowed. This means you can use MURS to carry packet radio transmissions. A slight correction: The FCC does not allow image transmissions, such as slow scan television, to be used over MURS.
- Low usage: MURS radios aren't very widely used at the moment, so you won't have much trouble finding a free channel.
Reference: MURS Home Page, http://www.provide.net/~prsg/murshome.htm