How to Use a Ham Radio Repeater
Repeaters are the backbone of local amateur radio communication. A repeater is an automatically-controlled station that receives on one frequency and simultaneously retransmits on another, extending the range of low-power handheld and mobile radios far beyond what they could achieve on their own. For most new hams, the local repeater is the first place they make a contact — and understanding how to access and use one properly is a fundamental operating skill.
Input and output frequencies
Every repeater uses two frequencies — an input (the frequency you transmit on) and an output (the frequency the repeater transmits on, which you listen to). The difference between these two frequencies is called the offset. On 2 metres the standard offset is 600 kHz — if the repeater output is 147.300 MHz, the input is 146.700 MHz. On 70cm the standard offset is 5 MHz. Your radio handles this automatically once you programme the offset correctly — you only need to know the output frequency and the offset direction (plus or minus).
CTCSS tones and access
Most repeaters require a continuous sub-audible tone transmitted along with your audio to open the repeater — this is called CTCSS (Continuous Tone-Coded Squelch System), or PL tone in common usage. The tone is inaudible to listeners but tells the repeater controller that your transmission is intentional and not interference. Without the correct tone, the repeater will not retransmit your signal. CTCSS tones range from 67.0 Hz to 254.1 Hz. The required tone for each repeater is listed in repeater directories like RepeaterBook.com.
Find local repeaters
Go to repeaterbook.com and search by your zip code or city. The results will show the output frequency, offset, CTCSS tone, and whether the repeater is open (available to all licensed amateurs) or closed (members only). Note down a few local repeaters to try, focusing on 2m and 70cm frequencies that are listed as open.
Programme the channel into your radio
Enter the output frequency, set the offset direction (+ or -) and offset amount (600 kHz for 2m, 5 MHz for 70cm), and enter the CTCSS tone. Give the channel a clear name in your radio memory — the repeater's callsign or location works well. If you have a programming cable and CHIRP software, you can programme multiple repeaters at once from a downloaded RepeaterBook CSV file.
Listen before transmitting
Before you key up on any repeater, listen for at least 30 seconds to make sure the frequency is clear and no one is in the middle of a QSO. Monitor long enough to understand whether the repeater is active, what kind of traffic it carries, and whether there is a net schedule you should be aware of. This is basic repeater courtesy and avoids stepping on ongoing conversations.
Test with a short call
Key up briefly and say "[your callsign], testing" to check if the repeater opens and retransmits your signal. You should hear your signal come back through the repeater with a slight delay. If the repeater has a courtesy tone (a short beep after each transmission), you will hear it. If nothing happens, check your CTCSS tone and offset settings.
Make a call
To call generally, say "[your callsign], listening" or "[your callsign] monitoring" and wait for a response. To call a specific station, say "[their callsign], this is [your callsign]." To call CQ (solicit any contact), say "CQ, CQ, this is [your callsign], listening." Keep your initial call brief — identify yourself and indicate you are looking for a contact.
During a QSO
Pause briefly between transmissions to allow other stations to break in — especially if someone has an emergency or priority call. Keep transmissions reasonably concise on a busy repeater. Use phonetics when giving your callsign if there is any chance it could be misheard. Say your callsign at least every 10 minutes and at the end of each contact as required by FCC Part 97. Do not use CB terminology — "10-4", "breaker", "handle" — on amateur radio frequencies.
Breaking in and nets
To break into an existing QSO on a repeater, wait for a pause between transmissions and say just your callsign once. The stations in QSO will acknowledge you and give you a turn. Do not say "break break" unless you have genuine emergency or priority traffic — on ham radio, "break" implies urgency. Many repeaters have scheduled nets — check in when they are running and follow the net control operator's instructions. Avoid casual QSOs on the repeater during net times.
| Band | Output Range | Standard Offset | Common CTCSS |
|---|---|---|---|
| 2m (144 MHz) | 144.600–148.000 MHz | -600 kHz (most) / +600 kHz (some) | 100.0, 127.3, 136.5 Hz (varies) |
| 70cm (440 MHz) | 440.000–450.000 MHz | +5 MHz (most) / -5 MHz (some) | 100.0, 127.3, 88.5 Hz (varies) |
| 1.25m (222 MHz) | 224.000–225.000 MHz | -1.6 MHz | Varies by repeater |
| 6m (50 MHz) | 51.620–51.980 MHz | -500 kHz | Varies by repeater |
Why can't I hear myself through the repeater when I transmit?
The most common causes are an incorrect or missing CTCSS tone, wrong offset direction (transmitting on the output instead of the input), or being out of range of the repeater's input coverage. Check your CTCSS tone matches the repeater listing exactly and verify the offset direction with a plus or minus sign.
Do all repeaters require a CTCSS tone?
No — some repeaters are carrier-access (open to any signal without a tone) and others use DCS (Digital Coded Squelch) instead of CTCSS. The repeater listing on RepeaterBook will indicate if no tone is required or if DCS is used instead. Always check the listing for the specific repeater you are trying to access.
What does the courtesy tone mean?
A courtesy tone is a short beep or series of tones the repeater controller transmits after each station finishes transmitting. It serves two purposes — it signals to other stations that the frequency is clear to transmit, and it gives the repeater controller a moment to reset its timeout timer. Wait for the courtesy tone before transmitting your response.
Can I use a repeater if I only have a Technician licence?
Yes — VHF and UHF repeaters on 2m, 70cm, and other bands above 30 MHz are fully available to Technician class licensees. This is where most new hams start. HF repeaters (rare) on 10m require at least a General class licence.
What is a linked repeater system?
A linked repeater system connects multiple repeaters together — either by radio links, internet (IRLP, EchoLink), or both — so that a transmission on one repeater is simultaneously heard on all linked repeaters. This can dramatically extend the geographic coverage of your signal. Many states have statewide linked repeater systems used for EmComm and regular nets.