Q codes are three-letter codes beginning with Q that stand for a whole question or answer, such as QTH for "my location is" or QRS for "send more slowly". Radio operators use them, together with short abbreviations like CQ, DE and 73, to say a lot in very few dots and dashes. They also work across languages: QTH means the same thing to an operator in Japan as in Brazil.
Where Q codes came from
The first Q codes were drawn up by the British government around 1909, as a list of abbreviations for British ships and coast stations. Forty-five of them were adopted internationally at the Radiotelegraph Convention in London in 1912, and since 1947 they have been part of the ITU's international Radio Regulations. Most were written for ships; radio amateurs adopted a handful and gave some a looser everyday meaning.
Question or answer
A Q code followed by a question mark is a question. On its own it is a statement or an answer. "QTH?" means "what is your location?". "QTH LONDON" means "my location is London".
The Q codes you will hear
| Code | As a question | As an answer |
|---|---|---|
| QTH | What is your location? | My location is ... |
| QSL | Can you acknowledge receipt? | I acknowledge receipt |
| QRZ | Who is calling me? | You are being called by ... |
| QRM | Are you being interfered with? | I am being interfered with |
| QRN | Is there atmospheric noise? | I am troubled by static |
| QSB | Are my signals fading? | Your signals are fading |
| QRS | Shall I send more slowly? | Send more slowly |
| QRQ | Shall I send faster? | Send faster |
| QSY | Shall I change frequency? | Change to another frequency |
| QRT | Shall I stop sending? | Stop sending |
| QRP | Shall I reduce power? | Reduce power |
| QSO | Can you communicate with ...? | I can communicate with ... |
Radio amateurs use some of these as nouns. A QSO is a contact, a QSL card is the postcard two operators exchange to confirm one, and QRP is low-power operating, a hobby in itself.
In Morse, QRS is --.- .-. .... If you hear someone too fast to follow, it is the most useful thing you can send.
Everyday abbreviations
Q codes are only part of the shorthand. These come up in almost every Morse contact:
| Abbreviation | Meaning |
|---|---|
| CQ | Calling any station |
| DE | From, or "this is" |
| K | Over, go ahead |
| R | Received |
| RST | Signal report: readability, strength and tone |
| TU | Thank you |
| PSE | Please |
| AGN | Again |
| FB | Fine, good ("fine business") |
| OM | Old man: any male operator, whatever his age |
| 73 | Best regards |
| 88 | Love and kisses |
73 and 88 come from the 92 Code, a list of numbered wire signals from the telegraph era. 73 has outlived nearly all the others: almost every Morse contact still ends with it. Write it as 73, never "73s", which would be "best regardses".
A whole contact in shorthand
Here is how a short, typical contact might go, with made-up call signs:
CQ CQ CQ DE K1ABC K1ABC K
K1ABC DE G4XYZ K
G4XYZ DE K1ABC TU UR RST 599 NAME BOB QTH BOSTON HW? KN
In plain English: "Calling anyone, this is K1ABC, over." "K1ABC, this is G4XYZ, over." "G4XYZ, this is K1ABC. Thank you. Your signal report is 599 (perfectly readable, very strong, clean tone). My name is Bob, I am in Boston. How do you copy? Go ahead, you only."
Every contact ends the same way: 73 and the prosign SK, end of contact. The prosigns have their own guide.
Hearing them
Most of this shorthand was chosen because it is quick to send. CQ, -.-. --.-, has a rhythm every radio amateur recognises at once, and 73, --... ...--, is the sound of a contact ending. Type any of them into the translator to hear them, or read on about getting started with Morse in amateur radio.