MORSE CODE TRAINER

Koch-method practice in the browser. Two characters at full speed, one more every time you clear ninety percent. No charts, no counting — you learn the sound or you do the round again.

What the Koch method is

In 1935 Ludwig Koch, a German psychologist, ran an experiment that contradicted everything the telegraph schools were doing. Instead of teaching the alphabet slowly and speeding it up, he sent just two characters at full target speed and had his students copy them until they were right nine times out of ten. Then he added a third character, at the same speed, and waited for ninety percent again. His group reached 12 words per minute in under fourteen hours of instruction — a result nobody teaching the conventional way could come close to.

The reasoning is straightforward once you accept what the skill actually is. Copying Morse is not decoding; it is recognition, closer to hearing a spoken word than to reading a cipher. A character sent at 20 WPM has a rhythm — dah-di-dah for K, two even dah dahfor M — and that rhythm is what the ear learns. Send the same character at 5 WPM and the rhythm dissolves into separate events that the conscious mind starts counting instead. Counting works up to about 10 WPM and then hits a wall, and everyone who learns that way has to demolish the habit before they can go faster. Koch's method never builds it.

Why it starts at full speed

The characters here are sent at 20 words per minute by default, which is faster than a beginner can copy continuous text. That is deliberate, and it is the part people are most tempted to change. The trick that makes it bearable is Farnsworth spacing: the dots and dashes keep their fast timing while the silence between characters is stretched, so your ear gets the correct, final shape of every character but your brain gets a moment to write it down. As you improve you close the gap by raising the effective speed, and the characters themselves never have to be relearned.

The other half of the method is the ninety percent rule. Two characters is a coin flip you cannot fake, so the score means something from the first round. Add a character only when you are genuinely at 90% and the difficulty stays roughly constant: each new character costs you a few rounds and then settles. Add one early and the errors compound, because you are now guessing between characters you never solidly knew. If a round comes in at 60%, the honest move is to run it again rather than turn the speed down.

Practice in short sittings — fifteen to twenty minutes, most days. Fatigue shows up as a sudden accuracy collapse, and pushing through it teaches you to guess. Keep your eyes off the current-set list while you copy; if you are checking which characters are possible, you are reasoning rather than hearing. When a character sticks stubbornly, the weak-spot list above will name it, and the translator will send it on repeat at whatever speed you like. For the timing rules behind all of this, see the CW primer.