From Wikipedia.
Selected Q codes were soon adopted by amateur radio operators. In December 1915, the American Radio Relay League began publication of a magazine titled QST, named after the Q code for “General call to all stations”. In amateur radio, the Q codes were originally used in Morse code transmissions to shorten lengthy phrases and were followed by a Morse code question mark (··— —··) if the phrase was a question.
Q codes are commonly used in voice communications as shorthand nouns, verbs, and adjectives making up phrases. For example, an amateur radio operator will complain about QRM (man-made interference), or tell another operator that there is “QSB on the signal” (fading); “to QSY” is to change your operating frequency, or to break in on a conversation QSK is often used even on VHF and UHF frequencies. (See also Informal usage, below.) Q
| Q-Code | Description |
|---|---|
| QRK | The readability of your signals (or those of …) is … (1 to 5). |
| QRK? | What is the readability of my signals (or those of …)? |
| QRM | I have interference. |
| QRM? | Do you have interference? |
| QRN | I am troubled by static. |
| QRN? | Are you troubled by static? |
| QRO | Increase power. |
| QRO? | Shall I increase power? |
| QRP | Decrease power. |
| QRP? | Shall I decrease power? |
| QRS | Send more slowly (… wpm) |
| QRS? | Shall I send more slowly? |
| QRT | I am suspending operation. /shutting off the radio |
| QRT? | Shall I cease or suspend operation?/ shutoff the radio |
| QRV | I am ready. |
| QRV? | Are you ready? |
| QRX | Please standby / I will call you again at … (hours) on … kHz (or MHz) |
| QRX? | Shall I standby / When will you call me again? |
| QRZ | You are being called by … on … kHz (or MHz) |
| QRZ? | Who is calling me? |
| QSB | Your signals are fading. |
| QSB? | Are my signals fading? |
| QSL | I am acknowledging receipt. |
| QSL? | Can you acknowledge receipt? |
| QSO | I can communicate with … direct (or by relay through …). |
| QSO? | Can you communicate with … direct or by relay? |
| QSY | Change to transmission on another frequency (or on … kHz (or MHz)). |
| QSY? | Shall I change to transmission on another frequency? |
| QTH | My position is … latitude…longitude |
| QTH? | What is your position in latitude and longitude (or according to any other indication)? |