J in Morse Code: ·−−−

The letter J in Morse code is ·−−−, spoken as "di-DAH-DAH-DAH": one short, then three long. That is 1 dot and 3 dashes, with a dash held three times as long as a dot. To remember it, think in JAWS JAWS JAWS (one quick beat, then three long ones).

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 J breaks down like this:

Timing of J (·−−−) at 20 words per minute
ElementSignalLength (units)At 20 WPM
Dot·160 ms
Gap(silence)160 ms
Dash3180 ms
Gap(silence)160 ms
Dash3180 ms
Gap(silence)160 ms
Dash3180 ms
Total for J13780 ms

How to signal J

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

How to remember J

Say in JAWS JAWS JAWS (one quick beat, then three long ones) in rhythm with the code and the pattern sticks: "di-DAH-DAH-DAH".

Words that start with J: Juliett ·−−− ··− ·−·· ·· · − −, jar ·−−− ·− ·−·, jungle ·−−− ··− −· −−· ·−·· ·, jigsaw ·−−− ·· −−· ··· ·− ·−−. The first is J's NATO phonetic name, which operators use to spell aloud.

J is one of the rarest letters in English and carries one of the heaviest codes to match: a dot followed by three full dashes, among the longest letter codes to send.