The Q codes are a set of three-letter codes that were originally used as an aid in
the communication between maritime mobile radio operators who didn't
share each other's language. Nowadays, they are used mostly by radio
amateurs, most of whom understand English, but need to express
themselves in a short and concise manner.
The meaning of the Q codes can be modified by suffixes. Most or all Q
codes can be turned into questions by appending a question mark (on
radiotelephony, the words Romeo Quebec (RQ) are used
instead. Thus "QRL" (I am busy), but "QRL?" (are you
busy?). Some of them can also get an affirmative or negative meaning, by
suffixing them with "C" (pronounced as Charlie)
or "NO" (pronounced as no), respectively. For
example, "QRP" (decrease transmitter power), but
"QRPNO" (don't decrease transmitter power).
Most of the Q codes can be found in ITU Recommendation M. 1172. There
are literally hundreds of them, all beginning with the letter Q, but
only a small portion of them are used by radio amateurs on a regular
basis. These include:
- Will you tell me my exact frequency (or that of ...)?
Your exact frequency (or that of ...) is ... kHz (or MHz).
- Are you busy?
I am busy (or I am busy with ...). Please do not interfere.
- Are you being interfered with?
I am being Interfered with
- Are you troubled by static?
I am troubled by static
- Shall I increase transmitter power?
Increase transmitter power.
- Shall I decrease transmitter power?
Decrease transmitter power.
- Shall I send faster?
Send faster (... words per minute).
- Shall I send more slowly?
Send more slowly (... words per minute).
- Shall I stop sending?
- Are you ready?
I am ready.
- Who is calling me?
You are being called by ... (on ... kHz (or MHz)).
- Are my signals fading?
Your signals are fading.
- Do you acknowledge receipt?
I acknowledge receipt.
- Can you communicate with ... direct (or by relay)?
I can communicate with ... direct (or by relay through ...).
- Shall I change to transmission on another frequency?
Change to transmission on another frequency (or on ... kHz (or MHz)).
- What is your position in latitude and longitude (or according to any, other indication)?
My position is ... latitude, ... longitude (or according to any other indication).
Radio amateurs also use Q codes in the middle of sentences as if they
were ordinary words. Together with morse code abbreviations this makes their speech totally
incomprehensible to casual onlookers:
- I finally got a QSO after listening on the wrong QRG for two weeks!
- I finally made a contact after listening on the wrong frequency for two weeks!
- I enjoy working portable QRP.
- I enjoy taking my equipment with me on trips, and make contacts using low power.
- There's a little bit QRM in the background at my QTH, please repeat the last thing you said.
- I can't hear what you're saying, my wife is yelling at me!