Q Codes (or Q-signals) are three letter combinations beginning with the letter "Q" representing common phrases or sentences. They were developed in the early twentieth century to facilitate maritime radiotelegraph communications. The list of codes has expanded over the years. While primarily used on CW, use of Q Codes has even crept into voice communication. You hear several used on VHF and UHF bands every day.
When used with a question mark (?), Q Codes represent a query; when used without, they are a statement. For example:
QTH? (What is your location?)
QTH Pittsburgh (My location is Pittsburgh)
FCC §97.113(a)(4) states – No amateur station shall transmit messages encoded for the purpose of obscuring their meaning.
So what about Q Codes? Well, their meaning is well known and they were designed to facilitate communication, not obscure it – so they are allowed. Several other common Amateur Radio words and phrases are also allowed for the same reason.
| Code | Question | Statement |
|---|---|---|
| QRA | What is your call sign? | My call sign is ... |
| QRG | What is my exact frequency? | Your exact frequency is ... |
| QRH | Does my frequency vary? | Your frequency varies. |
| QRI | How is the tone of my transmission? | The tone of your transmission is (1. Good; 2.Variable; 3. Bad) |
| QRJ | How many voice contacts do you want to make? | I want to make ... voice contacts. |
| QRK | What is the readability of my signals? | The readability of your signals is ... (1 to 5). |
| QRL | Are you (or this frequency) busy? | This frequency is busy. |
| QRM | Do you have interference? | I have interference. |
| QRN | Are you troubled by static? | I am troubled by static. |
| QRO | Shall I increase power? | Increase power. |
| QRP | Shall I decrease power? | Decrease power. |
| QRQ | Shall I send faster? | Send faster. |
| QRS | Shall I send more slowly? | Send more slowly. |
| QRT | Shall I stop sending? | Stop sending. |
| QRU | Have you anything for me? | I have nothing for you. |
| QRV | Are you ready? | I am ready. |
| QRW | Shall I inform ... that you are calling him? | Please inform ... that I am calling him. |
| QRX | When will you call me again? | I will call you again at ... |
| QRZ | Who is calling me? | You are being called by ... |
| QSA | What is my signal strength? | The strength of your signal is ... (1 to 5). |
| QSB | Are my signals fading? | Your signals are fading. |
| QSD | Is my keying defective? | Your keying is defective. |
| QSG | Shall I send ... messages at a time? | Send ... messages at a time. |
| QSK | Can you work break-in? | I can work break-in. |
| QSL | Can you acknowledge receipt? | I acknowledge receipt. |
| QSM | Shall I repeat the last message sent? | Repeat the last message sent. |
| QSN | Did you hear me on .. kHz (or MHz)? | I did hear you on ... kHz (or MHz). |
| QSO | Can you communicate with ... direct or by relay? | I can communicate with ... direct (or by relay through ...). |
| QSP | Will you relay a message to ...? | I will relay a message to .... |
| QSR | Do you want me to repeat my call? | Please repeat your call. |
| QSS | What working frequency will you use? | I will use the working frequency .... |
| QST | [No Query Version] | Here is a broadcast message to all amateurs. |
| QSU | Shall I send or reply on this frequency? | Send or reply on this frequency. |
| QSW | Will you send on this frequency? | I am going to send on this frequency. |
| QSX | Will you listen for ... on ... ? | I am listening for ... on .... |
| QSY | Shall I change frequency? | Change frequency. |
| QSZ | Shall I send each word or group more than once? | Send each word or group ... times. |
| QTA | Shall I cancel message No. ...? | Cancel message No. .... |
| QTC | How many messages have you to send? | I have sent ... messages. |
| QTH | What is your location? | My location is .... |
| QTR | What is the correct time? | The correct time is .... |
| QTU | At what times are you operating? | I am operating from ... to .... |
| QTX | Will you keep your station open for further communication with me? | I will keep my station open for further communication with you. |
| QUA | Have you news of ...? | Here is news of .... |
| QUC | What is the number of the last message you received from me? | The number of the last message I received from you is .... |
| QUD | Have you received the urgency signal sent by ...? | I have received the urgency signal sent by .... |
| QUE | Can you speak in ... (language), - with interpreter if necessary; if so, on what frequencies? | I can speak in ... (language) on .... |
| QUF | Have you received the distress signal sent by ...? | I have received the distress signal sent by ... at ... hours. |
The Difference Between CQ and QST
CQ is used to make a general call as an invitation for any operators listening on that frequency to respond. It is widely used on HF (both CW and voice) for initiating contacts.
QST means Here is a broadcast message to all amateurs
. Unlike CQ, replies to a QST are not expected.