Full quieting never felt so good.
A quick-reference glossary of terms you'll encounter when using GMRS radios, reading forums, or programming your radio. Terms are listed alphabetically.
A DTMF code transmitted automatically when you key up, identifying your radio to the repeater or other stations. Sometimes called PTT ID. See DTMF Call IDs.
A radio installed at a fixed location (home, office) typically powered by AC and connected to an outdoor antenna. Base stations offer the best range due to higher power and better antennas. See Handheld vs Mobile vs Base Station.
A unique identifier assigned by the FCC when you obtain your GMRS license. Format is typically WRXX### or WQXX###. You must identify with it during communications.
The default squelch mode on most radios — the speaker opens whenever any signal above the squelch threshold is received, regardless of tone. Compare with tone squelch (CTCSS/DCS).
A designated frequency or frequency pair used for communication. GMRS has 30 channels: 22 simplex channels and 8 repeater pairs.
Free, open-source software for programming two-way radios via a computer and programming cable. Supports most popular GMRS radios. See Programming with CHIRP.
A sub-audible tone transmitted alongside your voice signal. Repeaters and other radios can be set to only open squelch when they detect a specific CTCSS tone. Also called PL tone. See CTCSS & DCS Tones.
A digital alternative to CTCSS that serves the same purpose — controlling squelch access — but uses a digital code instead of an analog tone. Less common on GMRS repeaters than CTCSS.
The tones produced by a telephone-style keypad. Used on GMRS for call IDs, selective calling, and repeater control functions.
Operating on two different frequencies — one for transmit and one for receive. Repeater operation is duplex. The opposite is simplex (same frequency for both).
The US government agency that regulates radio communications, issues GMRS licenses, and enforces the rules.
A license-free two-way radio service sharing channels 1-22 with GMRS. FRS is limited to 2W with fixed antennas and no repeater access.
A licensed UHF two-way radio service operating on 462/467 MHz frequencies. Allows up to 50W, external antennas, and repeater use. Requires a $35 FCC license.
A portable, battery-powered radio you can carry. Sometimes called a "walkie-talkie," though that term is more associated with toy or FRS radios. GMRS handhelds typically output 2-5W.
Keying up on a repeater without identifying or speaking — just to hear the repeater tail and confirm you can reach it. Considered poor etiquette. Always identify when testing.
Unit of frequency equal to one million cycles per second. GMRS operates in the 462-467 MHz range.
A radio designed for vehicle installation, powered by the vehicle's 12V electrical system. Mobile radios typically output 15-50W. See Handheld vs Mobile vs Base Station.
An organized, scheduled on-air gathering where operators check in and communicate in a structured format. See Net Operations.
The frequency difference between a repeater's transmit (output) and receive (input) frequencies. GMRS uses a standard +5 MHz offset. See Repeater Offsets.
Another name for CTCSS tone, from Motorola's original trade name "Private Line." Same thing, different branding.
The button you press to transmit. Release it to receive. Half-duplex radio communication relies on this — only one person can talk at a time.
An automated station, usually on a hilltop or tower, that receives on one frequency and retransmits on another, greatly extending range. See What is a Repeater?
A short tone transmitted automatically when you release the PTT button, indicating you've finished speaking. Some operators find it helpful; others find it annoying. See Roger Beep and Courtesy Tones.
Transmitting and receiving on the same frequency — direct radio-to-radio communication without a repeater.
A circuit that mutes the receiver when no signal (or no signal with the right tone) is present. Prevents you from hearing constant static. See Squelch Settings.
A safety feature that automatically stops your transmission after a set time (typically 60-180 seconds). Prevents accidental continuous transmissions if the PTT gets stuck. See Transmit Timeout Timer.
The radio frequency range from 300 MHz to 3 GHz. GMRS operates in the UHF band at 462-467 MHz.
A hands-free mode where the radio transmits automatically when it detects your voice, without pressing PTT. Useful with headsets. See VOX: Voice Activated Transmit.
The unit of measurement for radio transmit power. More watts generally means more range, but antenna quality and height matter more. GMRS allows up to 50W on most channels.