As a communications medium Radio allows us to exchange messages over long distances, often under noisy conditions.  Abbreviations and symbolic codes can make these messages shorter and clearer, provided all parties understand the meaning behind the abbreviated expressions.  The message can vary, depending upon the medium being used.   Many of these abbreviations have their origins within Morse Code operating and have been modified for voice contacts.  

CQ

This is a reduction of the two word expression ‘seek-you’.  In the context of radio transmission it is used as a ‘general call to any or all stations’ and not to any specific station.  Normally heard on HF radio, it is a declaration that the operator is inviting any stations to respond, either for a brief contact or an extended chat.  This expression is not normally used on FM repeaters, where an operator may instead announce their callsign and indicating that they are ‘listening’ for any station.

DX

These letters have become synonymous with the words ‘long distance’.  A DX contact is a Long Distance contact relative to the band being used.  On VHF and UHF, DX may be just hundred kilometers.  On HF a DX contact can be literally anywhere on the planet.   Used in conjunction with a general call,  the expression CQDX is used by operators seeking distant stations.  For example a VK2 station calling CQDX is inviting contacts other than from other VK2 stations, preferably international stations.

SOS MAYDAY and PAN PAN

These abbreviations retain their historic telegraphic meanings determined more than a century ago.  SOS in Morse code is   . . . – – – . . . which is the international telegraphic distress message.  SOS = ‘Save Our Souls’.  The voice communications equivalent of this is ‘MAYDAY’.  Both are used to signal a distress event where loss of life is imminent, such as from a sinking ship or damaged aircraft.

Where a distress situation exists, but loss of life is not imminent then PAN PAN may be used to signify urgency.   Anyone hearing either message is required to listen to see if another station is responding to this call.  If no other station responds then an effort should be made to establish contact with the distressed caller.  At the first possible opportunity, these calls should be reported to police or similar authority.

K K K

In Telegraphy, ‘K’ is sent at the end of a transmission as ‘invitation to transmit’ meaning that the distant station is switching from send to receive and is inviting a response.  This abbreviation is also used in other digital mediums, such as Radioteletype, with the same meaning.

RYRY…

This abbreviation is linked to Radioteletype transmissions, which were originally mechanical in nature using the 5-bit Baudot code.  When a station was testing their transmission for reliability these two characters would be sent alternating for part or all of a line of text.   In the Baudot code the letter ‘R’ is the digital mirror of the letter ‘Y’.  Sending them in rapid succession would put maximum mechanical stress on the machine under test.   If there had been a ‘Numbers Shift’ character sent prior to an RYRY test, then the receiver would decode the transmission as 4646… instead.

When recorded on paper tape, consecutive RY’s look like this:

The Q code

The Q-code series was first developed by the British government around 1909 to provide a more compact way to convey messages by telegraphy.  These three letter codes always commencing with a ‘Q’ still remain in common use.  Most codes can be represented as a statement or as a question.  For example, ‘QRN’   I am troubled by static  or   Are you being troubled by static? 

Different codes were specialised for different sectors, such as marine and aviation.  Today the popular Q-codes for amateur radio use are limited and the details are no longer examinable. 

Here is a summary of commonly used Q-codes in Amateur Radio:

There are some other abbreviations to be aware of.  Here is a summary

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