What Q signals are
Q signals (also called Q codes) are three-letter codes that begin with the letter Q. They started in early radiotelegraphy as a fast way to send common questions and answers in Morse code. Amateurs adopted many of them, and a handful are now part of everyday ham radio speech even on voice.
Each code can be used two ways. Sent with a question mark, it asks something. Sent without one, it states or answers it. The official meanings come from international radio regulations, and amateur use often loosens them a little.
Question form versus statement form
Take QTH as an example:
- “QTH?” asks “What is your location?”
- “QTH is Denver” states “My location is Denver.”
The same pattern applies to most codes. “QRZ?” asks who is calling. “QSY?” asks whether you can change frequency, while “QSY 14.250” suggests moving to that frequency. On CW the question mark is sent as part of the message. On voice, you simply ask in a questioning tone or in plain words.
The most common Q signals
The table gives the meanings amateurs most commonly attach to these codes. Treat it as a practical guide, not a legal definition.
| Q signal | Common amateur meaning |
|---|---|
| QRL | Is this frequency in use? / This frequency is busy |
| QRM | Interference from other stations (man-made) |
| QRN | Interference from natural noise such as static |
| QRO | Use high power / increase power |
| QRP | Use low power / reduce power |
| QRQ | Send faster |
| QRS | Send more slowly |
| QRT | Stop sending / I am shutting down |
| QRV | I am ready |
| QRX | Stand by / I will call you again |
| QRZ | Who is calling me? |
| QSB | Signal fading |
| QSL | I acknowledge receipt / I confirm |
| QSO | A contact between two stations |
| QSY | Change frequency |
| QTH | Location |
A few of these deserve a closer look:
- QRM and QRN are easy to mix up. QRM is interference caused by people or equipment, such as another station on your frequency. QRN is natural, such as lightning static.
- QRP and QRO describe power. QRP generally means low power, and QRP operators often work with only a few watts.
- QSL is also the name of the card (or electronic confirmation) exchanged to confirm a contact. See the QSO/QSL comparison in our QTH article.
- QRS is often requested politely by a newer CW operator who needs the other station to slow down. It is also explained in our CW abbreviations guide.
Signal-report Q signals: QSA and QRK
Two Q signals are used to ask for or give signal reports. QSA concerns signal strength and QRK concerns readability, each on a scale of 1 to 5. In most amateur contacts, however, operators use the RST system instead. See our RST chart guide for how to read and give those reports.
Q signals on CW versus voice
Q signals were built for Morse code, where every character takes time to send. They are common on CW and used constantly there. On voice, many operators prefer plain language (“What is your location?”) and reserve Q signals for a few that have become part of the spoken hobby, such as QTH, QSO, QSL, QRP, QRM and QSY.
If you are new, plain language is always acceptable. Using Q signals incorrectly, such as saying “QRM” when you mean you have a poor signal, may confuse the other station more than it helps.
Q signals are not 10-codes
Some searches ask about “10 codes for radio.” Ten-codes such as “10-4” belong to public safety and some CB radio use, not amateur radio. Hams are generally expected to speak plain language on voice, and Q signals are a separate system. Do not assume ten-codes will be understood on amateur frequencies.
How to learn them
- Start with five: QTH, QSO, QSL, QRM, QRP.
- Add QSY, QRZ, QRS and QRT as you begin listening on CW or working contacts.
- Practise with a call sign spoken in the ITU phonetic alphabet so you can use codes in a realistic exchange.
- Keep the ham radio terms glossary nearby for other jargon.
Frequently asked questions
What frequency band does ham radio use?
There is no single band. Amateur radio has allocations in many parts of the spectrum, from the low and high frequency (shortwave) bands up through VHF, UHF and microwaves. The exact privileges depend on your country and license class, so check your national regulator’s band plan.
What is the 3-3-3 rule for radios?
This is not a standard amateur radio term that this site can point to, and it may refer to different things in different communities. If you saw it in a particular course or net, ask that group what they mean by it.
Are Q signals required to pass a license exam?
Requirements differ by country and exam. Many question pools touch on basic operating terms, but you should check your own exam’s syllabus.