A Guide for New GMRS radio comers

What is GMRS Radio?

The General Mobile Radio Service (GMRS) is a licensed radio service that uses channels around 462 MHz and 467 MHz. The most common use of GMRS channels is for short-distance, two-way voice communications using hand-held radios, mobile radios and repeater systems. In 2017, the FCC expanded GMRS to also allow short data messaging applications including text messaging and GPS location information.

Services that provide functionality similar to GMRS include the Citizens Band Radio Service (CBRS), the Family Radio Service (FRS) and the Multi-Use Radio Service (MURS).

For new users of GMRS , how to operate and use, I thought it would be useful to put together a brief primer to fill in newcomers interested in using the services with a few of the basics:

1, Frequently Used Terms
2, Simplex Operation
3, Repeater “Duplex” Operation
4, Coded Squelch Systems
5, Common operational practices

Before you are ready to buy GMRS radio, you need to get a GMRS license, You may apply for a GMRS license if you are 18 years or older and not a representative of a foreign government. If you receive a license, any family member, regardless of age, can operate GMRS stations and units within the licensed system. For information on obtaining a license; see “Getting a GMRS License“

Frequently Used Terms

Channel
A common frequency standardized either within a radio service or within a manufacture of radios. The GMRS has 22 channels defined by the FCC, and an additional 8 channels to be used as repeater input frequency (for a total of 30)
CTCSS
Continuous Tone Coded Squelch System, also marketed as Private Line (PL), Privacy Code or Sub-Channels, this is a constant tone which the radio sends out when transmitting, that is usually outside of the audible portion of a radio’s receiver and thus not apparent to the user. The tone is used to control the squelch on the receiving end, and lets radios and repeaters better handle channel interference, either from other stations on the same frequency, or other sources. Almost all repeaters require the use of a CTCSS tone, although they can use an open squelch for operation.
DCS
Digital Coded Squelch; a digital variant of the CTCSS tone. The radio sends out a continuous data pulse that represents a squelch code, again, typically outside of the audible portion of a radio’s receiver. DCS is less common on repeaters, but still commonly used. It is more resilient to interference than CTCSS, but also more sensitive to weak-signal problems.
Duplex
A method of radio operation where users transmit on one frequency/channel, and receive on another. This method of operation is used for operations with repeater stations.
FCC
Federal Communication Commission; the branch of government that administers and regulates communication services, including wireless radio.
Frequency
The rate at which something oscillates, usually measured in terms of oscillations per second. Megahertz is a unit of measurement for frequency, meaning millions of oscillations, or cycles, per second.
GMRS
General Mobile Radio Service; the name of the radio service created by the FCC located around 462Mhz and 467Mhz that is available for licensed use, and what we’re all about!
Repeater
A remote radio station that receives and rebroadcasts signals in real time. They are typically located at advantageous sites in terms of height above average terrain, including mountain and hilltops, on top of tall buildings or radio towers, or both! Repeaters can greatly boost the coverage range for radio communication devices, such as walkie talkies, vehicle mounted (mobile) stations, and fixed (base) stations.
Simplex
A method of radio operation where users transmit and receive on the same frequency/channel. This is most common for consumer-type handheld and mobile radios, and common in direct radio-to-radio communications
UHF
Ultra High Frequency; the name for the broad band in which the GMRS and many other radio services are located.

Simplex Operation

Simplex operation is a direct radio-to-radio method of using a radio, in which all users receive and transmit on the same channel; it is the most common type of operation that people are familiar with. You turn on the radio, dial in a channel (or frequency), and start talking. So long as everyone is on the same channel with the same squelch settings, and everyone is in range, all parties can hear one another.

Simplex operation generally works well over shorter distances, or when communicating using a base, mobile or handheld station that’s in a high location. Since there is no repeater, coverage is generally limited to a few miles, although depending on topography, much greater ranges may be possible. It is most easily deployed in the field among groups of people.

Common Operating Practices

It’s important not to take certain formalities too seriously; one should focus on using the radio in a matter that works well for them. With that said; there are a few general rules to keep in mind for starters:

GMRS users must identify their transmissions with their FCC issued call-sign every 15 minutes, or at the end of a series of transmissions.
Foul language is not allowed by the FCC

Keep a brief pause between transmissions so other stations can have a chance to break in if they need to.
When using a repeater, wait until after the courtesy tone to transmit – this is a brief beep or tone you may hear shortly after someone keys up the system. The intent is to give a pause for other stations to break in. Some repeaters will time-out after a few minutes if this is not followed and cease to transmit for a brief duration. Not all repeaters will have this.

How to get Your GMRS License?

To use these powerful radios and be able to use any of the long-range repeaters across the US (with permission of the owners), you’ll need an FCC license. See our post about How to Get a GMRS License for full details. The FCC recently lowered the cost from $70 to $35 for a ten year license which covers the whole family. The primary license holder must be 18 years old and minors may operate under their authorization, with the adult license holder ultimately being responsible for compliance with the rules of operation. A GMRS license may be issued in as little as 24 hours or less.

Decide What Kind of GMRS Radios You Need

Are you just needing a powerful set of walkie-talkies to use for outdoor adventures in a remote area, or do you want a combination of GMRS radios that includes handhelds, a home base unit and mobiles in your vehicles? Our own two-way radio setup consists of three mobile units, several handhelds and a base station using a directional antenna, aimed in the direction where we do most of our running around. This system gives us about ten to fifteen miles of range in a suburban area and up to 25 miles (farther if using repeaters) in the rural areas.

Listen First, Then Talk

Before you ever push the PTT button or key the mic, it’s best to listen to other licensed GMRS users talking in your area. While all channels are shared with the license-free FRS service, and even used legally by some businesses, you can usually tell which users are GMRS operators, either by the better audio quality or by their use of call-signs. Most of the repeaters and longer-range calling activity can be found on the high-power channels 15-22, where 50 watts output is allowed.

If there isn’t much activity in your area you always go to myGMRS.com, where you can hear live audio feeds from linked repeater networks around the country.