Simplex channels in GMRS allow for direct radio-to-radio communication without the need for a repeater. These channels operate in the 462 MHz and 467 MHz frequency ranges. Here’s a quick look at the frequency list and power limits:
Repeater channels improve communication range by using a repeater to relay signals. This is particularly useful in areas with obstacles or when you need to cover a larger area. GMRS repeater channels use 462 MHz for receiving and 467 MHz for transmitting.
Here’s the frequency list for repeater channels: