Q code

Although Q-codes were created when radio used Morse code exclusively, they continued to be employed after the introduction of voice transmissions.

To avoid confusion, transmitter call signs are restricted; countries can be issued unused Q-Codes as their ITU prefix e.g. Qatar is QAT.

[2] The Q-codes facilitated communication between maritime radio operators speaking different languages, 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.)

", but in the 1920s spark-gap transmitters were gradually being banned from land stations, making that meaning obsolete.

Some Q-codes are also used in aviation, in particular QNE, QNH and QFE, referring to certain altimeter settings.

These codes are used in radiotelephone conversations with air traffic control as unambiguous shorthand, where safety and efficiency are of vital importance.

[5] The QAA–QNZ code range includes phrases applicable primarily to the aeronautical service,[6] as defined by the International Civil Aviation Organization.

The QRA–QUZ code range includes phrases applicable to all services and is allocated to the International Telecommunication Union.

This structured use of Q-codes is fairly rare and now mainly limited to amateur radio and military Morse code (CW) traffic networks.

First defined in ICAO publication "Doc 6100-COM/504/1" and in "ICAO Procedures for Air Navigation Services, Abbreviations and Codes (PANS-ABC)" [Doc8400-4] (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.

or Maintain a vertical distance of ____ (figures and units) above clouds, smoke, haze or fog levels.

Q-codes still work when HF voice circuits are not possible due to atmospherics and the nearest vessel is one ionospheric hop away.

Later defined by ITU-R in Appendix 9 to the Radio Regulations Annex to the International Telecommunications Convention (Atlantic City, 1947).

ITU Radio Regulations 1990, Appendix 13: Miscellaneous Abbreviations and Signals to be Used in Radiotelegraphy Communications Except in the Maritime Mobile Service:[14] or Return to ____ (place).

or Will you request ____ to send two dashes of ten seconds followed by his call sign (repeated ____ times) on ____ kHz (or MHz)?

or I have requested ____ to send two dashes of ten seconds followed by his call sign (repeated ____ times) on ____ kHz (or MHz).

Most of the meanings are identical to the ITU definitions, however, they must be looked at in the context of amateur communications.

Since by regulation amateur communications are without charge, this Q-code couldn't make sense.

In December 1915, the American Radio Relay League began publication of a magazine titled QST, named after the Q-code for "General call to all stations".

Q-codes are commonly used in voice communications as shorthand nouns, verbs, and adjectives making up phrases.

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".

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.

QAC - Taken from the Articles of Association of the South Hampshire International Telegraphy Society, para 9: "...and amongst themselves they shall promote the Use of the Code QAC, which shall be taken as implying "All Compliments" and shall include:- VY 73 73 OM CUL BCNU & mni tnx fer nice/FB/rotten QSO GL GB hpe cuagn wid gud/btr/wrse condx mri Xms Hpi Nw Yr mni hpi rtrns gtgs fer Rosh Hoshanah/Id el Fitr/May Day/Tksgvg 88 to XYL/YL/Widow Ciao Cheerio & gud/FB/best DX or any Part or Parts thereof in any Permutation or Combination.

E.g., "The OCF [antenna type] is an interesting build but at my QTH a disappointing performer.

Historically, the location in the printed Callbook; modernly, "as given in online government records for my callsign".

During World War II, according to Bletchley Park’s General Report on Tunny,[27] German radio teleprinter networks used Q-codes to establish and maintain circuit connections.

In particular: QKP [ought to be 'QEP', not 'QKP' - the print in the source document isn't very clear] was to indicate the Lorenz 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.