MURS Info

Consider this a Frequently Asked Questions (FAQ) page.
I will update it as needed. Thanks! 

Basics: 

MURS is officially known as the Multi User Radio Service. It allows license-free communications for either personal or business use. The Federal Communications Commission's MURS information and rules web page can be viewed here.

Five frequencies are set aside for MURS:

You can use any of the "privacy tones", officially known as PL or CTCSS tones so that you will only hear transmissions from those who have the same tone. This is handy if there are other users on the same frequency and you only want to hear your group. These tones do not offer any level of privacy to your communications. You can hear the users of all tones simply by disabling the tone on your radio or by pressing the MON button found on most radios. 

Frequencies 1, 2, and 3 are usually have fewer users on them. Frequencies 4 and 5 may have fast food restaraunts, contractors, stores, etc. as they were originally part of the business band and which is the origination of the colored dot designations above.

All frequencies are shared between users. No user has more right to a frequency than another except during emergencies. If you are in more populated areas, you should consider using the first 3 frequencies to avoid interfering with users on frequencies 4 and 5.

Frequencies 1, 2, and 3 are narrow band frequencies. Frequencies 4 and 5 are wide band frequencies although you can also use narrow band on these two as well.

Narrow band emission is a transmission that is about 1/2 the size of wide band. This is done to allow more radio transmissions in the same amount of space. If you use two narrow band radios then all sounds fine. If you use a wide band radio and a narrow band radio then you will find that the narrow band radio will sound a bit softer on the wide band radio and the PL/CTCSS tone may not reliable activate the receiver on the narrow band radio. (By not using a PL/CTCSS tone, you can communicate much better between non-compatible radios.) Narrow band and wide band transmissions will have the same range as each other. It is simply a method used to increase the amount of available radio spectrum.

Read the information on this page to see if your radio is legal to use on MURS.

Range:

Communications range is the biggest variable with any radio system. Unless you have the capability of running a computer simulated coverage plot there is no way to estimate range. Do not fall for claims of 10, 12 or 18 mile range from the cheap plastic FRS/GMRS walkie talkies found in retail stores. These numbers are totally unrealistic. More likely your communications range will be in the neighborhood of 1/2 mile to 2 miles.

Local terrain is the biggest range limiter of communications range. The more obstacles between radios the shorter the range. Metal buildings, tall hills or mountains, and dense forests will all work against you. Open land and water will give you the greatest range. Use inside a vehicle without an external antenna will also decrease your range.

Increasing the elevation of one or both radios will also improve communications range. Standing on a high hill or top floor of a building will allow your radio to "see" further. 

MURS works best in outdoor situations or in large spaces. FRS/GMRS may have a slight advantage when both radios are inside a metal building. MURS is allowed to use external antennas such as the MURS Alert Base Station. A good quality antenna and coax will go a long way toward increasing your communications range.

Power output is another factor when determining communications range. MURS radios can have a maximum of 2 watts output. Use of a external gain antenna on a base radio will increase your effective power output. The difference between 1 and 2 watts does not make a huge difference in communications range.It usually takes about 10x increase in output power to increase range by 2x. The efficiency of an external antenna and the additional height will provide a better increase in range.

For more information about using an external antenna, please see this page.

MURS Alert Radio Compatibility:

Both MURS Alert radios - base and hand held - use narrow band emissions on all 5 frequencies. The Kenwood TK2100 MURS portables sold here previously also uses narrow band on all frequencies. 

Other manufacturers (such as the Motorola SP series) often use wide band on the frequencies 4 and 5. If your radio can be programmed on the frequencies 1, 2, or 3 then it is supposed to use narrow band emissions. You are legally allowed to use narrow band on all 5 MURS frequencies.

If you need to use a combination of narrow and wide band radios, you should disable the PL/CTCSS tone. It may work with the tone enabled but it may be  unreliable. You may also need to turn up the volume a bit to hear the narrow band radio better.