Overview
This lecture explains how GMRS repeaters work, how to connect to them, and how to set appropriate tones for proper operation.
GMRS Frequencies and Channels
- GMRS channels 15 to 22 are used for direct radio-to-radio communication.
- Repeater channels (15-22) transmit on different frequencies than they receive.
- When using a repeater channel, your radio transmits on a higher frequency (+5 MHz) and receives on the regular GMRS channel frequency.
How GMRS Repeaters Work
- Repeaters receive a signal on one frequency and re-transmit it on another, extending communication range.
- Your GMRS radio is pre-programmed to automatically handle transmit/receive frequency offsets for repeaters.
- You cannot manually change the offset on most GMRS radios; it is set by default.
Setting Tones for Repeaters
- To connect to most repeaters, you need to set the correct CTCSS (analog) or digital transmit tone on your radio.
- Match the transmit tone to the repeater's required tone found online or on charts.
- The receive tone is optional and only filters incoming transmissions; it does not affect your ability to connect.
Testing Connections and Troubleshooting
- To confirm connection, listen for a beep or use a secondary radio to check your voice relay.
- You must be within range and have the correct channel, frequency, and tones set for the repeater.
Key Terms & Definitions
- GMRS (General Mobile Radio Service) — A licensed UHF radio service for personal or family communication.
- Repeater — A station that receives a radio signal and re-transmits it on a different frequency.
- CTCSS Tone — Continuous Tone-Coded Squelch System for analog privacy.
- Digital Tone — Digital version of privacy and access code.
- Offset — The automatic frequency difference between transmit and receive channels on repeaters.
Action Items / Next Steps
- Identify local repeaters and their required tones.
- Program your GMRS radio's repeater channels and tones as needed.
- Test your setup with a second radio or by listening for a repeater acknowledgment.