The Q-code is a standardised collection of three-letter codes that each start with the letter "Q". It is an
operating signal initially developed for commercial
radiotelegraph
Wireless telegraphy or radiotelegraphy is transmission of text messages by radio waves, analogous to electrical telegraphy using cables. Before about 1910, the term ''wireless telegraphy'' was also used for other experimental technologies for t ...
communication and later adopted by other radio services, especially
amateur radio
Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communic ...
. To distinguish the use of a Q-code transmitted as a question from the same Q-code transmitted as a statement, operators either prefixed it with the military network question marker "" (dit dit dah dit dah) or suffixed it with the standard Morse question mark (dit dit dah dah dit dit).
Although Q-codes were created when radio used
Morse code
Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code is named after Samuel Morse, one of ...
exclusively, they continued to be employed after the introduction of voice transmissions. To avoid confusion, transmitter
call sign
In broadcasting and radio communications, a call sign (also known as a call name or call letters—and historically as a call signal—or abbreviated as a call) is a unique identifier for a transmitter station. A call sign can be formally assigne ...
s are restricted; no country is ever issued an
ITU prefix starting with "Q".
Codes in the range QAA–QNZ are reserved for aeronautical use; QOA–QQZ for maritime use and QRA–QUZ for all services.
"Q" has no official meaning, but it is sometimes assigned a word with
mnemonic
A mnemonic ( ) device, or memory device, is any learning technique that aids information retention or retrieval (remembering) in the human memory for better understanding.
Mnemonics make use of elaborative encoding, retrieval cues, and imag ...
value, such as "Queen" for example in QFE: Queen's field elevation, or "Query", "Question", "reQuest".
Early development
The original Q-codes were created, ''circa'' 1909, by the
British
British may refer to:
Peoples, culture, and language
* British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies.
** Britishness, the British identity and common culture
* British English, ...
government
A government is the system or group of people governing an organized community, generally a state.
In the case of its broad associative definition, government normally consists of legislature, executive, and judiciary. Government is a ...
as a "List of abbreviations ... prepared for the use of British ships and coast stations licensed by the
Postmaster General
A Postmaster General, in Anglosphere countries, is the chief executive officer of the postal service of that country, a ministerial office responsible for overseeing all other postmasters. The practice of having a government official respons ...
". The Q-codes facilitated communication between maritime radio operators speaking different
language
Language is a structured system of communication. The structure of a language is its grammar and the free components are its vocabulary. Languages are the primary means by which humans communicate, and may be conveyed through a variety of met ...
s, so they were soon adopted internationally. A total of forty-five Q-codes appeared in the "List of Abbreviations to be used in Radio Communications", which was included in the Service Regulations affixed to the
Second International Radiotelegraph Convention in London (The Convention was signed on July 5, 1912, and became effective July 1, 1913.)
The following table reviews a sample of the all-services Q-codes adopted by the 1912 convention:
Later use
Over the years the original Q-codes were modified to reflect changes in radio practice. For example, QSW / QSX originally stood for, "Shall I increase / decrease my spark frequency?", but in the 1920s
spark-gap transmitter
A spark-gap transmitter is an obsolete type of radio transmitter which generates radio waves by means of an electric spark."Radio Transmitters, Early" in Spark-gap transmitters were the first type of radio transmitter, and were the main type use ...
s were gradually being banned from land stations, making that meaning obsolete. By the 1970s, the ''Post Office Handbook for Radio Operators'' listed over a hundred Q-codes, covering a wide range of subjects including radio procedures, meteorology, radio direction finding, and search and rescue.
Some Q-codes are also used in
aviation
Aviation includes the activities surrounding mechanical flight and the aircraft industry. ''Aircraft'' includes fixed-wing and rotary-wing types, morphable wings, wing-less lifting bodies, as well as lighter-than-air craft such as hot air ...
, in particular QNE, QNH and QFE, referring to certain
altimeter setting Altimeter setting is the value of the atmospheric pressure used to adjust the sub-scale of a pressure altimeter so that it indicates the height of an aircraft above a known reference surface. This reference can be the mean sea level pressure ( QNH); ...
s. These codes are used in radiotelephone conversations with
air traffic control
Air traffic control (ATC) is a service provided by ground-based air traffic controllers who direct aircraft on the ground and through a given section of controlled airspace, and can provide advisory services to aircraft in non-controlled airs ...
as unambiguous shorthand, where safety and efficiency are of vital importance. A subset of Q-codes is used by the
Miami-Dade County, Florida
Miami-Dade County is a County (United States), county located in the southeastern part of the U.S. state of Florida. The county had a population of 2,701,767 as of the 2020 United States census, 2020 census, making it the most populous county in ...
local government for law enforcement and fire rescue communications, one of the few instances where Q-codes are used in ground voice communication.
The QAA–QNZ code range includes phrases applicable primarily to the aeronautical service, as defined by the
International Civil Aviation Organization
The International Civil Aviation Organization (ICAO, ) is a specialized agency of the United Nations that coordinates the principles and techniques of international air navigation, and fosters the planning and development of international sc ...
. The QOA–QQZ code range is reserved for the maritime service. The QRA–QUZ code range includes phrases applicable to all services and is allocated to the
International Telecommunication Union
The International Telecommunication Union is a specialized agency of the United Nations responsible for many matters related to information and communication technologies. It was established on 17 May 1865 as the International Telegraph Unio ...
. QVA–QZZ are not allocated. Many codes have no immediate applicability outside one individual service, such as maritime operation (many QO or QU series codes) or
radioteletype
Radioteletype (RTTY) is a telecommunications system consisting originally of two or more electromechanical teleprinters in different locations connected by radio rather than a wired link. Radioteletype evolved from earlier landline teleprinter o ...
operation (the QJ series).
Many military and other organisations that use Morse code have adopted additional codes, including the
Z code
Z (or z) is the 26th and last letter of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its usual names in English are ''zed'' () and ''zee'' (), with an occasi ...
used by most European and
NATO
The North Atlantic Treaty Organization (NATO, ; french: Organisation du traité de l'Atlantique nord, ), also called the North Atlantic Alliance, is an intergovernmental military alliance between 30 member states – 28 European and two No ...
countries. The Z code adds commands and questions adapted for military radio transmissions, for example, "ZBW 2", which means "change to backup frequency number 2", and "ZNB abc", which means "my checksum is abc, what is yours?"
Used in their formal question / answer sense, the meaning of a Q-code varies depending on whether the individual Q-code is sent as a question or an answer. For example, the message "QRP?" means "Shall I decrease transmitter power?", and a reply of "QRP" means "Yes, decrease your transmitter power", whereas an unprompted statement "QRP" means "Please decrease your transmitter power". This structured use of Q-codes is fairly rare and now mainly limited to amateur radio and military
Morse code
Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code is named after Samuel Morse, one of ...
(CW) traffic networks.
Breakdown by service
*QAA to QNZ – Assigned by the International Civil Aviation Organization (ICAO).
*QNA to QNZ – The
American Radio Relay League
The American Radio Relay League (ARRL) is the largest membership association of amateur radio enthusiasts in the United States. ARRL is a non-profit organization, and was co-founded on April 6, 1914, by Hiram Percy Maxim and Clarence D. Tuska of ...
(ARRL) has also developed its own
QN Signals
The QN Signals are Morse code operating signals that were introduced for Amateur radio net operation in 1939 on the Michigan QMN Net to lighten the burdens of net control operators. Originally created by a committee of the Detroit Amateur Radio As ...
for message handling located in this range. Even though they overlap with other signals, the ARRL determined that their exclusive use in
NTS nets limits confusion.
*QOA to QQZ – For the Maritime Mobile Service.
*QRA to QUZ – Assigned by the International Telecommunication Union Radiocommunication Sector (
ITU-R
The ITU Radiocommunication Sector (ITU-R) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communications.
Its role is to manage the international radio-frequency sp ...
).
Aeronautical Code signals (QAA–QNZ; ICAO)
First defined in ICAO publication "Doc 6100-COM/504/1" and in "ICAO Procedures for Air Navigation Services, Abbreviations and Codes (PANS-ABC)"
oc8400-4(4th edition 1989), the majority of the Q-codes have fallen out of common use; for example today reports such as QAU ("I am about to jettison fuel") and QAZ ("I am flying in a storm") would be voice or computerised transmissions. But several remain part of the standard
ICAO
The International Civil Aviation Organization (ICAO, ) is a specialized agency of the United Nations that coordinates the principles and techniques of international air navigation, and fosters the planning and development of international a ...
radiotelephony phraseology in aviation. These are also part of
ACP131, which lists all ITU-R Q-codes, without grouping them by aeronautical/marine/general use.
Maritime Mobile Service (QOA–QQZ)
This assignment is specified in ''RECOMMENDATION ITU-R M.1172''.
Q signals are not substantially used in the maritime service. Morse code is now very rarely used for maritime communications, but in isolated maritime regions like Antarctica and the South Pacific the use of Q-codes continues. Q-codes still work when HF voice circuits are not possible due to atmospherics and the nearest vessel is one ionospheric hop away.
All services (QRA–QUZ)
First defined by the Washington 1927 ITU Radio Regulations. Later defined by ITU-R in Appendix 9 to the Radio Regulations Annex to the ''International Telecommunications Convention'' (Atlantic City, 1947). The current callsign table is found in ITU-R Appendix 42. Current interpretation of the Q-code can be found in ITU-R Appendices 14 and 15.
ITU Radio Regulations 1990, Appendix 13: Miscellaneous Abbreviations and Signals to be Used in Radiotelegraphy Communications Except in the Maritime Mobile Service:
Amateur radio
Amateur radio has adapted two different sets of Q-codes for use in amateur communications. The first set comes from the ITU civil series QRA through QUZ. Most of the meanings are identical to the ITU definitions, however, they must be looked at in the context of amateur communications. For example, QSJ? asks what the charges are for sending the telegraph. Since amateur communications are without charge, this Q-code would not make sense.
The second set is the set of
QN Signals
The QN Signals are Morse code operating signals that were introduced for Amateur radio net operation in 1939 on the Michigan QMN Net to lighten the burdens of net control operators. Originally created by a committee of the Detroit Amateur Radio As ...
, used only in ARRL
NTS nets. These operating signals generally have no equivalent in the ACP 131 publication or ITU publications, and are specifically defined only for use in ARRL NTS nets. They are not used in casual amateur radio communications.
Selected Q-codes were soon adopted by
amateur radio operator
An amateur radio operator is someone who uses equipment at an amateur radio station to engage in two-way personal communications with other amateur operators on radio frequencies assigned to the amateur radio service. Amateur radio operators hav ...
s. In December 1915, the
American Radio Relay League
The American Radio Relay League (ARRL) is the largest membership association of amateur radio enthusiasts in the United States. ARRL is a non-profit organization, and was co-founded on April 6, 1914, by Hiram Percy Maxim and Clarence D. Tuska of ...
began publication of a magazine titled ''
QST
''QST'' is a magazine for amateur radio enthusiasts, published by the American Radio Relay League (ARRL). It is a membership journal that is included with membership in the ARRL. The publisher claims that circulation of ''QST'' in the United St ...
'', named after the Q-code for "General call to all stations". In amateur radio, the Q-codes were originally used in Morse code transmissions to shorten lengthy phrases and were followed by a Morse code question mark (··— —··) if the phrase was a question.
Q-codes are commonly used in voice communications as shorthand nouns, verbs, and adjectives making up phrases. For example, an amateur radio operator will complain about QRM (man-made interference), or tell another operator that there is "QSB on the signal" (fading); "to QSY" is to change your operating frequency, or to break in on a conversation QSK is often used even on VHF and UHF frequencies. (See also
Informal usage, below.)
Q-codes as adapted for use in amateur radio
Notes for response to radiotelegraph Q-codes
Responses to a radiotelegraph Q-code query or a Q-code assertion may vary depending upon the code. For Q-code assertions or queries which only need to be acknowledged as received, the usual practice is to respond with the letter "R" for "Roger" which means "Received correctly". Sending an "R" merely means the code has been correctly received and does not necessarily mean that the receiving operator has taken any other action.
For Q-code queries that need to be answered in the affirmative, the usual practice is to respond with the letter "C" (Sounds like the Spanish word "Si"). For Q-code queries that need to be answered in the negative, the usual practice it to respond with the letter "N" for "no". For those Q-code assertions that merely need to be acknowledged as understood, the usual practice is to respond with the
prosign
Procedural signs or prosigns are shorthand signals used in Morse code radio telegraphy procedure, for the purpose of simplifying and standardizing radio communication protocol. They are separate from Morse code abbreviations, which consist mainly ...
(or ) which means "understood". On telegraph cable networks "KK" was often used at the end of a reply to a Q-code to mean "OK" or "Acknowledged". This practice predates amateur radio as telegraph operators in the late 19th century are known to have used it.
Informal usage
QLF – "Are you sending with your left foot? Try sending with your left foot!" A humorously derogatory comment about the quality of a person's sending.
QNB – QNB? “How many buttons on your radio?” “QNB 100/5” Means there are 100 and I know what 5 of them do.
QSH – "Stay happy and healthy."
QSK – "I can hear you during my transmission" – refers to a particular mode of Morse code operating often called
QSK operation (full break-in) In CW Morse code operations, QSK or full break-in operation describes an operating mode in which the transmitting station can detect signals from other stations between the elements (dots and dashes) or letters of the Morse transmission. This allo ...
in which the receiver is quickly enabled during the spaces between the dits and dahs, which allows another operator to interrupt transmissions. Many modern
transceivers
In radio communication, a transceiver is an electronic device which is a combination of a radio ''trans''mitter and a re''ceiver'', hence the name. It can both transmit and receive radio waves using an antenna, for communication purposes. Thes ...
incorporate this function, sometimes referred to as ''full break-in'' as against ''semi-break-in'' in which there is a short delay before the transceiver goes to receive.
QSY – "Change to transmission on another frequency"; colloquially, "move
change address. E.g., "When di
GKBQSY from Northolt to Portishead?"
QTH – "My location is ____"; colloquially in voice or writing, "location". E.g., "The OCF ''
ntenna type' is an interesting build but at my QTH a disappointing performer."
QTHR – "At the registered location ____"; chiefly British use. Historically, the location in the printed Callbook; modernly, "as given in online government records for my callsign". E.g., "You can contact me QTHR".
German use during World War II
During World War II, according to
Bletchley Park
Bletchley Park is an English country house and estate in Bletchley, Milton Keynes ( Buckinghamshire) that became the principal centre of Allied code-breaking during the Second World War. The mansion was constructed during the years following ...
’s ''General Report on Tunny,''
German radio teleprinter networks used Q-codes to establish and maintain circuit connections.
In particular: QKP
ught to be 'QEP', not 'QKP' - the print in the source document isn't very clearwas to indicate the
Lorenz cipher
The Lorenz SZ40, SZ42a and SZ42b were German rotor stream cipher machines used by the German Army during World War II. They were developed by C. Lorenz AG in Berlin. The model name ''SZ'' was derived from ''Schlüssel-Zusatz'', meaning ''cipher ...
machine setting for each message and, QZZ to indicate that the daily key change was about to take place at the sender's station.
See also
*
ACP-131
ACP-131 is the controlling publication for the listing of Q codes and Z codes. It is published by the Combined Communications Electronics Board (CCEB) countries (Australia, New Zealand, Canada, United Kingdom and United States), and revised from t ...
*
NOTAM Code
NOTAM Code is an aeronautical radiotelegraph and radiotelephony brevity code used to transmit information about radio navigation aids, airports, lighting facilities, dangers to aircraft, and actions related to search and rescue. All NOTAM Codes st ...
*
Amateur radio
Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communic ...
*
Brevity code
Brevity codes are used in amateur radio, maritime, aviation and military communications. The codes are designed to convey complex information with a few words or codes. Some terms are classified to the public.
List of brevity codes
* ACP-131 A ...
*
International Code of Signals
The International Code of Signals (ICS) is an international system of signals and codes for use by vessels to communicate important messages regarding safety of navigation and related matters. Signals can be sent by flaghoist, signal lamp ("bl ...
*
International maritime signal flags
International maritime signal flags are various flags used to communicate with ships. The principal system of flags and associated codes is the International Code of Signals. Various navies have flag systems with additional flags and codes, and ...
*
Morse code
Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code is named after Samuel Morse, one of ...
*
Prosigns for Morse code
Procedural signs or prosigns are shorthand signals used in Morse code radio telegraphy procedure, for the purpose of simplifying and standardizing radio communication protocol. They are separate from Morse code abbreviations, which consist mainly ...
*
QRA locator The QRA locator, also called QTH locator in some publications, is an obsolete geographic coordinate system used by amateur radio operators in Europe before the introduction of the Maidenhead Locator System. As a radio transmitter or receiver locatio ...
*
QSK operation (full break-in) In CW Morse code operations, QSK or full break-in operation describes an operating mode in which the transmitting station can detect signals from other stations between the elements (dots and dashes) or letters of the Morse transmission. This allo ...
*
Ten-code
Ten-codes, officially known as ten signals, are brevity codes used to represent common phrases in voice communication, particularly by law enforcement and in Citizens Band (CB) radio transmissions. The police version of ten-codes is officially k ...
*
Z code
Z (or z) is the 26th and last letter of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its usual names in English are ''zed'' () and ''zee'' (), with an occasi ...
Footnotes
References
External links
Easy to Read Code Graphic*
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{{DEFAULTSORT:Q Code
Amateur radio
Encodings
Morse code
Operating signals
Telecommunications-related introductions in 1909