GMRS Help

The General Mobile Radio Service (GMRS) is a licensed radio service (a portion of the UHF frequencies) set into designated channels around 462 MHz and 467 MHz. GMRS is set aside for family and community communications, travel, and emergencies.

The most common use of GMRS channels is for short-distance, two-way voice communications using hand-held radios, mobile radios, and repeater systems. GMRS shares channels and frequencies with FRS (Family Radio Service) but allows for higher transmit power on certain channels and allows the use of repeaters to transmit further distances, which FRS does not.

To obtain a GMRS license you must go to the FCC CORES website and first create an FRN (FCC Registration Number)

Once you have created an FRN, you will need to fill out information to get a GMRS license registered under that FRN.

CLICK HERE To view a step by step video showing how to apply for your GMRS license.

GMRS is used with both handheld HT (handy talkie) and mobile units that can be installed in a vehicle or setup at a fixed location as a base unit.

GMRS HTs have removable antennas (FRS radios do not have removable antennas) which allow you to use smaller more manageable antennas or longer more capable ones that give you more range. HTs can even be connected to mobile antennas on a vehicle or base station antenna.

GMRS mobile units can have up to 50 watts of power which can be used on certain designated GMRS channels (17-22 and their corresponding repeater channels often designated as 23-30 ) for better clarity and strength of signal. However, antennas make the bigger difference in range than pure power does.

The distance of GMRS radios varies by wattage, and line of sight. wattage is the output power of the radio, and line of sight is basically an unobstructed invisible line between your radio, and another. the better the line of sight, the farther you can transmit.

A repeater is a radio, or pair of radios, set up as a relay station which can receive and re-transmit your signal a further distance than your radio could alone. Repeaters have a input frequency to receive transmissions, and an output frequency to send them back out. In GMRS the transmit frequency is always +5 MHz greater than the receive frequency (example 462.600 for receive, and 467.600 for transmit).

Repeaters allow radio users who are far apart, or have obstructions between them which inhibit direct line of sight, to communicate. Because the UHF band (in which GMRS operates) works best with a direct line of sight between radios, repeaters are usually set up with antennas on tall masts, on tall buildings, or on mountain tops to allow further communication. Repeaters are able to transmit at the maximum allowable wattage (50watts) for GMRS as defined by the FCC. There are both Amateur ("Ham") radio and GMRS repeaters.

Repeaters utilize a receiver radio which listens on a specific frequency. If it receives the proper CTCSS tone or DTS code to allow access to the repeater with the transmission, it hands off the signal to a sending radio which is also a part of the repeater system to re-transmit the received signal on a different frequency. Designated GMRS repeater channels are actually pairs of frequencies separated by 5 MHz. One frequency is for sending the transmission to the repeater and the other is for receiving the retransmitted transmissions from the repeater.

The Mesa Crest Repeater Club maintains multiple repeaters around the southern California area to allow communication between our members even if normally mountains, urban sprawl, or simply distance would prevent connecting.

The average range on most of our repeaters is a diameter of 100 miles around the repeater’s location. In some cases and conditions range can be greater than that.

We have repeater coverage maps that illustrate the signal coverage for each of our towers.

Yes. GMRS specific radios come programmed with the GMRS frequency set, there are 22 simplex channels for radio to radio communications, and 8 duplex channels for radio to repeater communications. Bear in mind that the repeater frequencies are there, but the tones to activate the repeaters are not. So to use simplex channels you will not have to do any programming, however to access repeaters you will need to program in the correct CTCSS tones and/or DCS codes.

Almost all repeaters are activated by a tone frequency that can be sent by repeater capable radios. These tones can be an analog signal (CTS or CTCSS or PL) or a digital Signal (DCS or DPL). One is for activating the repeater, and the other is for screening out non toned traffic from other transmissions on the frequency. Mesa Crest Repeater Club Members are issued the tones to program into your radios when you join.

First, you may not be doing anything wrong. You won’t hear a “tail squelch” from our repeaters, so if you’re unsure your radio is being heard by the repeater, we encourage our members to transmit - say their call sign and ask for a radio check. Someone is almost always monitoring to give you feedback.

If no one is responding to your radio check it could mean a few different things. First, you may be using a simplex GMRS channel rather than a repeater channel. For instance, on the chart to the left, note that channel 15 (462.550) is a simplex channel and although it uses the same receive frequency as the repeater channel equivalent (channel 23 on some radios) for that frequency, simplex channels that are pre-programmed in a GMRS radio will not transmit +5 Mhz to the paired (duplex) frequency (467.550) that the repeater is listening for. Use one of the pre-programmed repeater channels (above 22) or create a new separate channel with the correct frequency to automatically get the +5 transmit frequency needed for duplex communication with the repeater.

Secondly, check to make sure you have the proper CTCSS or DCS tones/codes programmed to activate the repeater on transmit (tx). The rx setting is optional if you want to hear EVERYTHING on the frequency you can leave it off, but if you want to only hear what comes from our repeater put in the rx tone or code as well.

While we encourage all of our members to learn how to program, operate, and care for their radios, we do have people who can help new members by assisting them in programming their radios. As a rule, each radio has it’s own Customer Programming Software, and they all differ by make and model. Chances are, we have someone that has experience with the radio being used, and can help you get it programmed for use with the repeaters.

GMRS licenses are open to use by anyone in the license holders direct family (mom, dad, sister, brother, wife, children, even in-laws) as long as they identify with that call sign and a designator (you would be WXXX 999, and wife would be WXXX 999 unit 2, child unit 3, Mom unit 4, Dad unit 5, etc…)

The repeaters are open to all members of the Mesa Crest Repeater Club, there is no additional charge for family members.