The Code, Timing & Abbreviations — Vol 2: The Alphabet, the Tree, and the Shorthand

2.1 The alphabet

Here is the whole International Morse alphabet — letters, numerals, and the two element lengths (Figure 1). This is the chart to laminate.

Notice the elegance the code inherited from Murray-era frequency-weighting (the History dive): the commonest letters are the shortest. E is a single dit, T a single dah, I and A and N and M just two elements each. The rarer the letter, the longer its code. That’s not an accident; it’s what makes Morse fast.

2.2 Decoding by branching: the Morse tree

There’s a lovely way to see the whole alphabet’s structure at once — as a binary tree (Figure 2). Start at the top; for each element you hear, a dit steps left and a dah steps right; where you stop is your letter. It’s not really how a fluent operator copies (they hear whole letters, and whole words, as sounds), but it’s a wonderful map of how the code is built, and a genuine decoding aid when you’re learning.

2.3 Punctuation and prosigns

Beyond letters and numbers, a working operator needs punctuation and prosigns — and here’s the key distinction: a prosign is two or more letters run together as a single symbol with no gap between them, used as a procedural signal. The only thing that turns the letters A and R into the prosign AR is the absence of the 3-unit letter gap. The essentials:

Table 1 — Beyond letters and numbers, a working operator needs punctuation and prosigns — and here's the key distinction: a prosign is two or more letters run together as a single symbol with no gap between them, used as a procedural signal. The only thing that turns the letters A and R into the prosign AR is the absence of the 3-unit letter gap. The essentials

Symbol / prosign	Meaning	Code
Period .	full stop	·−·−·−
Comma ,	comma	−−··−−
Question ?	question mark	··−−··
Slash /	fraction bar	−··−·
AR (= +)	end of message	·−·−·
BT (= =)	break / new section	−···−
SK (VA)	end of contact	···−·−
KN	go ahead, named station only	−·−−·
AS	wait / stand by	·−···
Error (HH)	error — correct text follows	········ (8 dits)

(Yes, AR shares its pattern with +, and BT with = — the prosign is the punctuation, told apart by context and by being sent run-together.)

2.4 Cut numbers

In contests, where you send the same signal report (“599”) thousands of times, operators shorten the digits into cut numbers — a letter that sounds almost like the number but is quicker to send. The two everyone uses are T for 0 and N for 9, so “599” becomes the famous “5NN.” The common set:

Table 2 — In contests, where you send the same signal report ("599") thousands of times, operators shorten the digits into cut numbers — a letter that sounds almost like the number but is quicker to send. The two everyone uses are T for 0 and N for 9, so "599" becomes the famous "5NN." The common set

0 = T	1 = A	2 = U	3 = V	5 = E	7 = G	8 = D	9 = N

(T=0, N=9, A=1, and E=5 are near-universal; the middle ones vary by operator, and 4 and 6 are usually sent in full.)

2.5 Q-codes: a question in three letters

The Q-codes are the genius shorthand of radio — three-letter codes that each carry a whole sentence, and that work as either a question or a statement. They came off the wire (the Telegraph dive) and went worldwide. The ones every CW operator knows:

Table 3 — The Q-codes are the genius shorthand of radio — three-letter codes that each carry a whole sentence, and that work as either a question or a statement. They came off the wire (the Telegraph dive) and went worldwide. The ones every CW operator knows

Q	Means		Q	Means
QRZ	who’s calling me?		QSY	change frequency
QRM	man-made interference		QTH	my location is…
QRN	static / atmospheric noise		QSL	I acknowledge / QSL card
QSB	your signal is fading		QRT	I’m shutting down
QRP	low power (≤5 W)		QRV	I’m ready
QRO	increase power		QRX	stand by, I’ll call again
QSO	a contact / conversation		QTC	I have messages for you

2.6 The abbreviations — and the fist

Finally, the plain shorthand: abbreviations (unlike prosigns, sent as normal separate letters) that trim the common words of a QSO down to a few characters. A short conversation in CW is dense with them:

Table 4 — Finally, the plain shorthand: abbreviations (unlike prosigns, sent as normal separate letters) that trim the common words of a QSO down to a few characters. A short conversation in CW is dense with them

73	best regards		DE	”from” (this is…)
88	love and kisses		K	over — any station transmit
OM	old man (any op)		R	received / roger
YL / XYL	young lady / wife		CQ	calling any station
FB	fine business (great)		AGN	again
HI	laughter (ha-ha)		ES	and (&)
WX	weather		HR	here / hear
PSE	please		TNX / TU	thanks
RST	signal report		GM/GA/GE	good morning/afternoon/evening

Put it together and “CQ CQ CQ DE N0SWN N0SWN K” — calling any station, this is N0SWN, over — is a complete, efficient hail in a handful of characters. And when I send it by hand, it carries the one thing no abbreviation can encode: my fist. Every operator’s hand-sent Morse has a subtly individual rhythm — a hair long on the dahs, a certain lilt in the spacing — and a good fist is even, clean, and easy to copy, while a bad one runs its letters together. Experienced operators recognize each other on the air by fist alone, the way you’d know a friend’s handwriting. It is the human fingerprint left on a code made of nothing but time — and it’s exactly what the next dive, Learning & Operating CW, is about building in your own hand.

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2.6.1 Sources (Vol 2)

• International Morse alphabet, numerals, punctuation, and prosigns (AR/BT/SK/KN/AS, 8-dit error; AR=+, BT==): ITU-R M.1677-1; Wikipedia “Prosigns for Morse code”; morsecode.world. https://en.wikipedia.org/wiki/Prosigns_for_Morse_code
• Cut numbers (T=0, N=9, A=1, E=5 universal; U/V/G/D vary): johndcook.com; masteringmorse.com; ac6v.com. Q-codes: Wikipedia “Q code”; ARRL Q-signals. CW abbreviations: hamuniverse.com; maritimeradio.org. The “fist” (individual, recognizable rhythm): Wikipedia “Morse code.” Cross-link: Morse & CW → Learning & Operating CW.