The Q-code is an international set of abbreviations that was created at the beginning of the last century to simplify radiotelegraph communication. Each code is composed by three letters always starting with Q. Each code can be a question if followed by a question mark or an answer (or statement) if not. To avoid confusion, no station call-sign begins with Q. Even if initially designed for telegraphy, it's also used in voice communications.
The original Q-signals were created in the early 1900s by the British Postmaster General for use by British ships and coast stations. They proved to be so useful, however, that radio operators worldwide began using them. One reason they proved to be so useful is that they can even be used by operators speaking different languages. When an English-speaking operator receives QTH? they understand it to mean, “What is your location?” A Slovak-speaking operator will translate that to, “Aká je tvoja poloha?” while a German-speaking operator will hear, “Wo befinden Sie sich?”
At the Second International Radiotelegraph Convention in London in July 1912, the delegates adopted a list of 45 different Q-codes. Many of these Q-codes are no longer used. For example, QRF stands for “I am bound from ________.” But, many, such as QTH, QSY, QRM, and others, are still used today more than 100 years later.
Amateur radio operators use a subset of the full international Q-code and they use it extensively still today. In many countries, learning this code is necessary to obtain a ham radio license; the exact subset used may slightly vary from country to country. Hereunder the most common codes. Sometimes Q-codes are used informally with a slightly different meaning.
In informal ham language, some codes have slightly diverted from their original meaning and are used just as a replacement for a specific word. The table below summarizes the most common:
|QRQ||High speed CW|
|QRS||Low speed CW|
|QRSS||Very low speed CW|
|QRT||Shut down the station|
|QRZ?||Who is calling me?|
|QSL||Confirmation or card to confirm contact|