F in Morse Code: ··−·
The letter F in Morse code is ··−·, spoken as "di-di-DAH-dit": two short, one long, then one short. That is 3 dots and 1 dash, with a dash held three times as long as a dot. To remember it, think get a HAIR-cut (only the third syllable is stressed).
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 F breaks down like this:
| Element | Signal | Length (units) | At 20 WPM |
|---|---|---|---|
| Dot | · | 1 | 60 ms |
| Gap | (silence) | 1 | 60 ms |
| Dot | · | 1 | 60 ms |
| Gap | (silence) | 1 | 60 ms |
| Dash | − | 3 | 180 ms |
| Gap | (silence) | 1 | 60 ms |
| Dot | · | 1 | 60 ms |
| Total for F | 9 | 540 ms | |
How to signal F
- Tap it: two 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: two short, one long, then one short. Use quick blinks for dots and slow, deliberate eye closes for dashes, keeping the rhythm steady.
- Flash it: two 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 F
Say get a HAIR-cut (only the third syllable is stressed) in rhythm with the code and the pattern sticks: "di-di-DAH-dit".
Words that start with F: Foxtrot ··−· −−− −··− − ·−· −−− −, flag ··−· ·−·· ·− −−·, fire ··−· ·· ·−· ·, forest ··−· −−− ·−· · ··· −. The first is F's NATO phonetic name, which operators use to spell aloud.
Play F backwards and you get L (di-DAH-di-dit). Morse puzzles and reversed-audio easter eggs lean on this pair all the time.