C in Morse Code: −·−·

The letter C in Morse code is −·−·, spoken as "DAH-di-DAH-dit": one long, one short, one long, then one short. That is 2 dots and 2 dashes, with a dash held three times as long as a dot. To remember it, think CO-ca CO-la (the classic mnemonic: stressed syllables are the dashes).

Timing: how long each part lasts

Morse timing is built from one unit, the length of a dot. A dash is 3 units, and the silence between the elements of a single character is 1 unit. At 20 words per minute, one unit is 60 ms, so C breaks down like this:

Timing of C (−·−·) at 20 words per minute
ElementSignalLength (units)At 20 WPM
Dash3180 ms
Gap(silence)160 ms
Dot·160 ms
Gap(silence)160 ms
Dash3180 ms
Gap(silence)160 ms
Dot·160 ms
Total for C11660 ms

How to signal C

  • Tap it: one long, one short, one long, then one short. A short is a quick tap; a long is a heavier tap, or a quick tap followed by a slight hold, about three times as long.
  • Blink it: one long, one short, one long, then one short. Use quick blinks for dots and slow, deliberate eye closes for dashes, keeping the rhythm steady.
  • Flash it: one long, one short, one long, then one short. Short flashes for dots; for dashes, hold the light on about three times longer. Any flashlight or phone screen works.

How to remember C

Say CO-ca CO-la (the classic mnemonic: stressed syllables are the dashes) in rhythm with the code and the pattern sticks: "DAH-di-DAH-dit".

Words that start with C: Charlie −·−· ···· ·− ·−· ·−·· ·· ·, cabin −·−· ·− −··· ·· −·, candle −·−· ·− −· −·· ·−·· ·, copper −·−· −−− ·−−· ·−−· · ·−·. The first is C's NATO phonetic name, which operators use to spell aloud.

C opens CQ, the 'calling anyone' broadcast that radio operators have sent for over a century. Hearing CQ on the air is an open invitation for anyone listening to reply.