General Mobile Radio Service
General Mobile Radio Service (GMRS) is a radio application that is particularly popular in the USA and South America.
Anyone who has a GMRS radio license may use GMRS radio equipment to communicate on their own land / property, on hikes, sports excursions, while trekking and paragliding tours outside their own property. The radio devices may be handed over to relatives, partners and members of the immediate family of the license holder, even if they do not have a radio license. The special thing about these handy devices is the range of up to 25 kilometers.
Typically, GMRS radios are small handheld radios similar to the common walkie-talkie-style devices for Freenet , PMR radio (PMR446) and SRD radio (formerly LPD) or CB radio .
Technical information
GMRS uses frequencies in the UHF band. The use of relay stations is supported. The antennas on the device can be exchanged or stationary antennas attached. GMRS comprises 15 channels, seven of which GMRS shares with the license-free Jedermannfunk Family Radio Service (FRS). Hybrid devices that support both GMRS and FRS are common and almost exclusively available now. The FRS channels 8 to 14 cannot be used by GMRS devices; an FRS radio is required for these frequencies. With the hybrid devices, only channels 8-14 are from the FRS band. A license is also required for transmission on these shared channels if, as is usually the case, the effective transmission power is higher than 500 milliwatts (½ watt ). As a rule, the GMRS radios have a transmission power of 5 watts. It is up to the operator of the device to observe and comply with the applicable regulations.
With good visibility, for example from mountain peak to mountain peak or in the air, connections over more than 100 km are definitely possible.
List of channels
| Surname | Subband (MHz) | Upper band (MHz) |
|---|---|---|
| "550" | 462,550 | 467,550 |
| "575" | 462.575 | 467.575 |
| "600" | 462,600 | 467,600 |
| "625" | 462.625 | 467.625 |
| "650" | 462,650 | 467,650 |
| "675" | 462.675 | 467.675 |
| "700" | 462,700 | 467,700 |
| "725" | 462.725 | 467.725 |
The sub-band frequency is the input frequency of the relay station . The upper band frequency is the output frequency of the relay station
| Surname | FRS channel | Frequency (MHz) |
|---|---|---|
| "5625" | FRS 1 | 462.5625 |
| "5875" | FRS 2 | 462.5875 |
| "6125" | FRS 3 | 462.6125 |
| "6375" | FRS 4 | 462.6375 |
| "6625" | FRS 5 | 462.6625 |
| "6875" | FRS 6 | 462.6875 |
| "7125" | FRS 7 | 462.7125 |