K in Morse code

K is a short beep framed by two long ones. At 18 WPM each dash lasts 200 ms and the dot 66.7 ms, with a 66.7 ms silence between them, so the whole letter takes 600 ms. Because it is symmetrical, it sounds the same whichever end you start listening from.

• Say it:

  dah-di-dah, heavy, light, heavy.

• Tap it:

  a long press, a quick tap, then another long press.

• Flash it:

  long blink, short blink, long blink.

• Write it:

  a hyphen, a period and a hyphen with no gaps.

A worked example: OK is --- -.- in Morse code, 23 units in all. That is 11 units for O, a 3-unit gap between the letters and 9 for K, about 1.5 seconds at 18 WPM. Any longer word works the same way on the Morse code translator.

The ITU's Morse standard, ITU-R M.1677-1, lists -.- by itself as the invitation to transmit. A station calling another sends the call sign it wants, the word DE, its own call sign and then K. At the end of a message it sends the cross signal .-.-. and then K, so the other side knows it can reply.

Radio amateurs use a close relative, KN, sent as one signal with no gap between the letters. It means “over to you, and only the station I am working should answer”. These signals and dozens of others are listed under Morse code abbreviations.

Say KAN-ga-ROO with the stress on the first and last syllables: the stressed beats are the dashes and the light middle one is the dot. “KICK the CAN” has the same rhythm. In Douglas Harder's written mnemonics, where tall letters are dashes and short ones dots, K is the word Kit.

K is also where many learners begin. In the Koch method course it is the first of 41 characters, followed by M. For a phrase for every other letter, see the Morse code mnemonics guide.

• N:

  one dash shorter, -. stopping after the dot.

• C:

  one dot added, so -.-. ends short.

• Y:

  one dash added, so -.-- ends with two long tones.

• R:

  every dot and dash swapped, so .-. is K's mirror image.

• O:

  the middle dot held long, so --- is three dashes.

Because K reads the same in both directions, there is no separate “K backwards” to learn. The risk is at the end: if you stop listening after the dot, you hear N. The Sound-alike drill plays these close pairs until you can tell them apart.