We like using GMRS radios, especially when we head out for some camping or overland adventures in remote areas where cellular coverage is limited. If we travel with a group of vehicles off-road, a GMRS repeater with good coverage allows us to stay in touch with everyone in our party over hundreds of square miles.
We often mention in our gear reviews how some radios are “repeater capable” but what does that really mean? Hopefully, this post will shed some light on how and when you can use this powerful feature on your GMRS radio. Here is how to use a GMRS repeater, if your radio has that capability built-in.
What Do You Need To Use a GMRS Repeater?
In order to use a GMRS repeater, your radio needs to have this capability. Fixed mount mobiles such as the Midland MXT-500 and MXT-575 are repeater capable, as well as handheld GMRS radios such as the Baofeng UV-9G. We won’t get into how to set up your GMRS radio to use repeaters, since programming varies from model to model, but here is the basic principle:
Typically a GMRS radio that’s repeater capable will have channels already set up for this feature, which the user can modify either through the radio’s front panel or by using a programming cable and computer. The repeater channels correspond to the 8 high power GMRS channels (15-22) on the receive side but when using them your radio transmits on an offset frequency that’s 5 MHz higher*.
You may hear traffic from a repeater on those regular channels, but to use the repeater you’ll need to switch to the corresponding repeater channel and possibly enter special tones to activate the machine. If this all sounds complicated, it’s not really that hard to set these features up, once you know the basics.
How Do You Use a GMRS Repeater For Longer Range?
When we use our radios in the normal way, talking to others in our group on channel 16 for example, we’re using the same channel or frequency to transmit and receive. This is called simplex mode. Our signal simply leaves the antenna and travels towards the person we want to talk to, if they’re within range. In situations where the distance is too far or if there’s something such as a mountain in the way of our signal, we wouldn’t be able to talk to them.
Enter GMRS repeaters, which act sort of like cell towers or relay stations to pick up our signal and send it out farther than what was ordinarily possible. GMRS repeaters are often located on high mountaintops, such as the 462.600 machine in Silverton, CO, and some may cover hundreds of square miles.
How Does a Repeater Work?
Because we can’t use the same frequency for this relaying process without causing interference, the repeater “listens” on a second radio frequency that’s 5 MHz higher than the one we’re listening on. When you transmit on a repeater channel your radio’s signal goes out on one frequency – that only the repeater can hear – then gets rebroadcast on the normal frequency – channel 16 for example.
On GMRS radios that are “repeater capable” all this switching is done automatically if you’ve selected one of the repeater channels.
How to Find and Ask Permission to Use GMRS Repeaters
Most GMRS repeaters are owned by local clubs or individuals and not all are for public use. One of the best resources for finding and learning how to use local GMRS repeaters is myGMRS.com, which features an interactive map that gives contact info, status (open repeater, private, permission required, etc.) along with the tones which may be required to access the repeater. Besides myGMRS.com, you can search online for local repeater clubs and request access to machines they maintain. If you find your repeater-capable GMRS is connecting to a repeater it’s always best to check ownership status before using it.
What are GMRS Repeater Tones?
CTCSS tones are used by many repeaters to control access and keep the machine from rebroadcasting unwanted signals. When using a repeater channel on your radio, you’ll likely have to set a privacy tone for the repeater you want to use, otherwise it won’t respond. There’s a good chance that there may be several repeaters in one area, even possibly using the same channel, but with different access tones. This is why it’s good to have a radio that allows you to add multiple DIY custom channels.
Some repeaters also broadcast a CTCSS tone on the receive end, which you can use if you only want to hear signals coming from that repeater. Also, some repeater owners are now using DCS (Digital Coded Squelch) instead of CTCSS. The principle is similar, except instead of an analog tone DCS uses a digital signal. Most newer handhelds and mobile GMRS radios are able to transmit either CTCSS tones or DCS coded signals.
Open Repeaters and the 141.3 Hz GMRS Travel Tone
When we get a new GMRS radio and program it using Chirp, one of the first things we do is set all the repeater channels to transmit a CTCSS tone of 141.3 Hz. This is a commonly used tone to access “open repeaters”, which use the informal GMRS “travel tone” of 141.3 Hz. Not all repeaters using this tone are considered “open”. Be sure you verify that the machine you’re using welcomes all users before talking on it.
How to Use a GMRS Repeater – Etiquette
We’re not experts on GMRS radio etiquette, so don’t take our advice as “gospel”, just as a starting point, since every repeater owner has their own expectations of how users should act. On myGMRS.com there is a live audio feed where you can listen to other licensed users talking. There you can get an idea of how call signs are used and how conversations are initiated. As per FCC rules, you must use your GMRS call sign at the end of each transmission, or every 15 minutes if in a conversation.
Some General Rules of Repeater Etiquette
- Don’t “kerchunk” or needlessly activate a repeater without speaking. It won’t harm the repeater, but it’s just annoying.
- Always be courteous. Listen first and call only when you’re sure the channel is clear
- Don’t hog repeater airtime.
- Identity using your call sign at the end of each transmission – or every 15 minutes if in a conversation.
- Avoid using a repeater when you can use a simplex channel.
- Obtain permission to use the repeater, when required.
- No profanity or any other stuff you’re not supposed to do on GMRS.
- Help support the GMRS repeater you regularly use, since they’re expensive to operate.
How Do I Set Up My Own Repeater?
Any licensed user is allowed to set up a GMRS repeater as long as the antenna height complies with FAA rules and the setup uses FCC accepted equipment. For under $400 you can purchase a ready-to-go GMRS repeater setup using a Retevis RT97 portable repeater that plugs into your vehicle’s cigarette lighter. Before just jumping in and setting up a repeater, make sure you are aware of other repeater systems operating in the vicinity, what tones or DCS codes they use and be sure to follow FCC guidance on emissions, antenna height, etc.
Helpful Tip: If you have a radio that has dual channel watch like the Baofeng GMRS-9R, set one to the repeater channel and the other for the regular simplex channel, so you can easily switch back and forth if necessary to maintain communication. Some radios, like the Btech GMRS-V2 also have a dual PTT button, which can be useful for “talking around” the repeater when possible. Be sure to show all your users how and when it’s appropriate to switch to point-to-point simplex transmission instead of going through the machine.
Why Would Anyone Need to Set Up a GMRS Repeater?
Let’s say that you’re headed out with a group of people to spend a few days exploring a certain area – hiking from a central base-camp where there’s no cell phone reception. A self-contained repeater unit could be set up in camp in just a few minutes and serve as sort of a relay station, helping handhelds that wouldn’t be able to reach each other to communicate. Temporary, portable GMRS repeaters can be very useful for things like off-road vehicle events, cross-country marathon races, large outdoor events or anywhere else where a central “relay” station could help radios reach each other more effectively. As with any GMRS radio, repeaters should not be used for business purposes, only for personal and recreational use.
Other GMRS Repeater Odds and Ends
If you’ve grasped the concept of how a GMRS repeater works you’re ready for “networked” repeaters. These are repeaters connected by phone lines or the internet to broadcast your signal even farther, up to nationwide. One could, for example, talk from a campsite in a national forest in Utah, back to a family member in Los Angeles using a networked repeater system. An app called Zello allows anyone with a smartphone to use GMRS repeaters that utilize this service, offering even more possibilities for nationwide GMRS communication for licensed users.
Knowing how to use a GMRS repeater can really expand the capabilities of your radio and allow you to keep in touch with other off-road vehicles in many areas where cell phones still don’t work. Be sure to see our post How to Get a GMRS License if you don’t already have one.
Other Solutions For Getting More Range From Your GMRS Radios
For places where we need a big more range from our truck’s mobile GMRS radio, we sometimes bring along a small directional antenna, called a Yagi. We can set this directional antenna up on a 12′ painters pole in just a few minutes at our campsite. The Yagi antenna has 11 dB gain, and with it we’ve been able to talk to other GMRS users via simplex and through repeaters, up to 150 miles away when camped at a high point. For more tips you can see our post How to Increase GMRS radio range.
* When using your GMRS mobile on repeater channels, keep in mind these are 5 MHz higher in frequency. Make sure your antenna is tuned for these channels by setting its SWR or Standing Wave Ratio. See How to Easily Set GMRS Antenna SWR for more info.
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