D in Morse Code — −··

The letter D in Morse code is a dash followed by two dots (− · ·). It is the mirror of U (· · −) and one of the more common letters in English text.

In International Morse Code, the letter D is encoded as −·· — consisting of 2 dots and 1 dash. The total transmission length is 7 time units. In the NATO phonetic alphabet, D is represented by the word "Delta" to avoid miscommunication over radio.

To transmit the letter D (−··) in Morse code, follow these steps:

1. Send a long signal (dash) — 3 time units then pause for 1 unit
2. Send a short signal (dot) — 1 time unit then pause for 1 unit
3. Send a short signal (dot) — 1 time unit

At 20 WPM (words per minute), one time unit equals 60 milliseconds. So the letter D takes approximately 420ms to transmit at this speed.

The letter D appears in approximately 4.3% of English text, making it the #10 most common letter out of 26.

D has a moderate frequency in English. Its Morse code length of 3 elements represents a balance between code complexity and the letter's usage rate.

The Morse code representation for the letter D is −··, which is vocalized as "dah-di-dit". This encoding is part of the International Morse Code standard adopted in 1865 and still in use worldwide today.

When transmitting D by sound, the dots should be short, crisp signals and the dash should last exactly three times the duration of a dot. Proper timing between elements (1 unit of silence) is crucial for the receiver to correctly decode the letter.

In practical use, the letter D can be transmitted using various methods: a telegraph key, a radio transmitter, a flashlight (short flash = dot, long flash = dash), a whistle, or even by tapping. The medium doesn't matter — only the relative timing between short and long signals.

For amateur radio operators using CW (Continuous Wave) mode, the letter D is one of the most frequently transmitted characters, appearing in countless common words and abbreviations.