The General Mobile Radio Service (GMRS) is a licensed radio service that uses channels around 462 MHz and 467 MHz frequencies. Let’s cover some details about the different channels and frequencies.
Channel Categories Explained:
Simplex Channels (1-7, 15-22): These are direct radio-to-radio channels where you communicate directly with other users on the same frequency. Channels 1-7 are limited to 5 watts, making them suitable for short to medium-range communication. Channels 15-22 allow up to 50 watts of power, providing significantly greater range in open terrain.
Interstitial Channels (8-14): These low-power simplex channels are limited to just 0.5 watts (500 milliwatts) and are intended for short-range communications. They’re often used for activities like communication between vehicles in a convoy or around a campsite. These channels sit between the main GMRS frequencies and are shared with FRS (Family Radio Service) radios.
Repeater Channels (23-30): These channels are specifically designated for repeater operation. A repeater is a device installed at an elevated location that receives your transmission on one frequency (the input) and simultaneously retransmits it on another frequency (the output) with higher power and from a better location. This dramatically extends your communication range. The repeater input and output are separated by exactly 5 MHz. When programming your radio for repeater use, you’ll set it to transmit on the input frequency and receive on the output frequency.
Note: Most radios have the 5Mhz step frequency already setup in the pre-programmed repeater channels.
Power Levels and Range:
The maximum legal power output varies by channel. Higher power generally means greater range, but actual range depends heavily on terrain, obstacles, antenna height, and antenna quality. In ideal conditions with line-of-sight, a 50-watt GMRS radio can communicate 20+ miles, while 5-watt radios typically achieve 1-5 miles depending on conditions.
| Channel | Frequency (MHz) | Max Power | Notes | Repeater Output (MHz) |
| 1 | 462.5625 | 5W | ||
| 2 | 462.5875 | 5W | ||
| 3 | 462.6125 | 5W | ||
| 4 | 462.6375 | 5W | ||
| 5 | 462.6625 | 5W | ||
| 6 | 462.6875 | 5W | ||
| 7 | 462.7125 | 5W | ||
| 8 | 467.5625 | 0.5W | Interstitial channel | |
| 9 | 467.5875 | 0.5W | Interstitial channel | |
| 10 | 467.6125 | 0.5W | Interstitial channel | |
| 11 | 467.6375 | 0.5W | Interstitial channel | |
| 12 | 467.6625 | 0.5W | Interstitial channel | |
| 13 | 467.6875 | 0.5W | Interstitial channel | |
| 14 | 467.7125 | 0.5W | Interstitial channel | |
| 15 | 462.55 | 50W | ||
| 16 | 462.575 | 50W | ||
| 17 | 462.6 | 50W | ||
| 18 | 462.625 | 50W | ||
| 19 | 462.65 | 50W | ||
| 20 | 462.675 | 50W | ||
| 21 | 462.7 | 50W | ||
| 22 | 462.725 | 50W | ||
| 23 | 462.55 | 50W | Repeater Input | 467.55 |
| 24 | 462.575 | 50W | Repeater Input | 467.575 |
| 25 | 462.6 | 50W | Repeater Input | 467.6 |
| 26 | 462.625 | 50W | Repeater Input | 467.625 |
| 27 | 462.65 | 50W | Repeater Input | 467.65 |
| 28 | 462.675 | 50W | Repeater Input | 467.675 |
| 29 | 462.7 | 50W | Repeater Input | 467.7 |
| 30 | 462.725 | 50W | Repeater Input | 467.725 |
