Morse code abbreviations and Q codes (73, QTH, QSL)

How to read it

ARRL’s glossary gives 73 as ham lingo for “best regards”, used on both phone and CW (Morse) toward the end of a contact, and describes Q signals as three-letter symbols beginning with Q, used on CW to save time. The Q codes come from the ITU’s list for radio services, ITU-R M.1172, where each code has a question form, sent with a question mark, and an answer or advice; the QOA to QQZ series there is reserved for the maritime mobile service. In Morse, 73 is −−··· ···−−, the figures 7 and 3.

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Q codes, the ITU’s and amateurs’

Some meanings drifted on the amateur bands. The ITU’s QTH asks for a ship’s latitude and longitude, where ARRL gives it as a station’s location; the ITU’s QSO asks whether a station can communicate with another, where to amateurs a QSO is the conversation itself. A QSL card, in ARRL’s glossary, is a postcard confirming a contact between two hams. ARRL’s General class question pool tests QRS (“send slower”), QRL? (“Are you busy?”, or “Is this frequency in use?”) and QSL (“I acknowledge receipt”).

Other abbreviations

ITU-R M.1172 lists R for received, TU for thank you and PSE for please. DE is “from” (ITU) or “from” or “this is” (ARRL), and K invites the other station to transmit. CQ is the general call. RST, in ARRL’s glossary, is a signal report in numbers: R for readability, S for strength and T for tone.

Numbers from the telegraph

ARRL’s glossary notes that in the Western Union company’s “92 code”, used even before the American Civil War, 30 meant “the end. No more.” Prosigns such as SK, which ARRL connects to that 30, are on Morse code prosigns (AR, SK, BT, KN).