Q Codes

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Every Radio Amateur is familiar with some of the more frequently used ‘Q Codes’ such as QTH for the location of your station, QRM for interference from another station, QSB for the fading of a received signal etc, but why were these codes invented and how many of them are there?  Codes in general were originally invented in the early days of Telegraphic Communication to simplify and reduce the vocabulary in use, (so that if one only got part of the message you could have a good guess at what the rest was).  It was also invaluable as an aid to communication between operators who had no language in common.  It is important to distinguish codes of this sort from “secret codes” designed to obscure the meaning from unwanted observers or listeners.  It is interesting to note that ‘CB radio’ and American police use a similar procedure but use “number codes” instead of a sequence of letters, although much of their communication is in spoken “English”.  It must be said that the use of number codes in ‘CB’ is more to do with producing a dramatic effect than it is for improving clarity of communication.

Although Q codes were originally designed for use in Morse Code, many of them are now used in voice communication with similar advantages of brevity and clarity.  While on the subject of other codes which fulfil the above functions, i.e. conveying the meaning of several words in a single statement by a short combination of numbers or letters, it is worth pointing out that several other methods of communication have employed similar techniques.  For example, the British Navy, and later, all the naval and mercantile fleets of the world communicated by flag signals from about the time of Henry Vlll to the end of the second World War.  In fact, in 1857 the British Board of Trade published a list of 70,000 signals which could be sent using only 18 different flags, and it became known as “The International Code of Signals”.  Every sailor in the British Navy could identify every flag by name, but the code of signals book was required to read the more obscure messages.

Back to Q codes

The idea of Q-Codes was first mooted at the Berlin International Radiotelegraph Conference of 1906, and a formal list of Q-Codes was instituted at the London Radiotelegraph Convention of 1912.  The complete list contained some 380 definitions, although some were listed as ‘non allocated’.

With the decline in the use of Morse for commercial communications, Q codes are probably used less now than in the past, but are still extensively used by amateurs and several public services.  There were well over 60 listed in the American 1926 Radio Amateur’s Handbook, but only 33 in the 1946 edition of the British Amateur Radio Handbook.  However, the total number available, (though most are seldom used), is considerable, and they are arranged in categories.  For example, codes starting with QAA down to QNZ, (a total of 149), are exclusively allocated to the aeronautical service.  (If you listen on the “Air Bands”, or to the “Volmet” stations, you will almost certainly have heard the term “QNH”, the barometric pressure at sea level to readjust the aircraft’s altimeter for the local area).

The letters QOA to QQZ, (a total of 15 allocated), are reserved for the Maritime Services and QRA to QUZ are reserved for other Services, including Radio Amateurs.  The German police tend to use QV to QZ plus a third letter, and the Russian military use mainly QW & QY plus a third letter.  In the latter case, exact translation is not always possible as some letters in the Russian Cyrillic alphabet have no directly corresponding letter in our Latin alphabet.  Whatever the system or country of origin, not all the letters available are used, although they may have been at some time in the past.  A list of those commonly used by Radio Amateurs is shown in several editions of the Amateur Radio Handbook.


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