The letter J in Morse code is · — — — — one dot followed by three dashes. It is one of the longest single-letter codes in the entire Morse alphabet, sharing a 4-signal length with C, F, H, L, P, Q, V, X, Y, and Z.
Here is what J looks like as physical signal blocks — short dot followed by three long dashes:
Memory trick: J looks like a hook — one short flick then three long strokes. Think of drawing the letter J: you make a short mark then pull down three long curves. One dot, three dashes.
In Samuel Morse's original 1837 code, letters were assigned shorter codes based on how often they appear in English text. J is one of the rarest letters in English — appearing in less than 0.15% of text — so it received one of the longer, more complex codes. The most common letters got the simplest codes: E = · and T = —.
Several letters share the 4-signal pattern with J. Click any card to hear it:
In the NATO phonetic alphabet used by aviation and military, J is represented by the word "Juliet". When spelling out a callsign or code letter by letter on radio, operators say "Juliet" to make J unmistakeable — especially important when distinguishing it from G or other letters that sound similar in noisy conditions.