Q–Codes have been around since around the beginning of the 20th century and consist of 3 letters, starting, surprisingly enough, with the letter Q. They are a short–hand method of relaying information, rather than sending and receiving longer sentences. Q–Codes are very effective at relaying the information they represent, so effective in fact, that they have made it into spoken conversations (think QSO, QSL, QSB, etc.)
The following table lists the more commonly encountered Q–Codes.
| Q-Code | Question | Reply | Comment |
|---|---|---|---|
| QRL | Are you busy? | I am busy. | More commonly used to check to see if a frequency is in use. |
| QRM | Am I being interfered with? | I am being interfered with: 1 — 5 | QRM is man–made interference. |
| QRN | Are you troubled by static? | I am troubled by static: 1 — 5 | QRN is naturally occuring interference. |
| QRO | Should I increase transmitter power? | Increase transmitter power. | |
| QRP | Should I decrease transmitter power? | Decrease transmitter power. | Also used to indicate low power (5W or less) operation. |
| QRQ | Should I sent faster? | Send faster. (WPM) | |
| QRS | Should I send more slowly? | Send more slowly. (WPM) | |
| QRT | Should I stop sending? | Stop sending. | Also used to indicate a station is going off the air. |
| QRV | Are you ready? | I am ready. | Also used to indicate that a station is on the air. |
| QRZ | Who is calling me? | You are being called by … | |
| QSB | Are my signals fading? | Your signals are fading. | |
| QSL | Can you acknowledge receipt? | Acknowledging receipt. | QSL Cards anyone? |
| QSO | Can you communicate with …? | I can communicate with … direct (or by relay through …) | Commonly used to indicate an amateur radio contact on the air. |
| QST | Is there a message for hams? | Here is a message for hams. | Now you know why the most popular ARRL magazine is called QST. |
| QSY | Should I transmit on another frequency? | Transmit on another frequency (…kHz or MHz) | Also used to indicate that the operator is changing frequency, usually to avoid QRM. |
| QTH | What is your position (location)? | My position (location) is … |