Koch Lesson 1: Characters K and M

Why this step

Ludwig Koch’s first pair is two dash-heavy letters that never sound like each other. K is three elements with a dit in the middle (-.-). M is two equal dahs (--). You learn contrast, not an alphabet chart.

What to hear

Listen for K as “dah-dit-dah” — the same rhythm as the invitation-to-transmit family (the letter K, not a real on-air call). M is a pair of long tones with no dit at all. If you catch yourself counting “dash, pause, dash,” the character speed is too slow; raise WPM and use Farnsworth gaps instead.

Drill

Copy only K and M. Do not add R until twenty recent copies sit at about 90% in the trainer. Drill mixed order, not KM-KM-KM. A useful check: can you name the letter before the sound finishes?

Letter groups you can type in the translator once the ear is warm: K, M, KM, MK

Pitfall

Visual flashcards of -.- versus -- train your eyes. Koch only works if the first contact is audio. Close the alphabet chart while the session runs.

Practice text

Copy groups: MK KM K M KMK MMM KKK. Say each letter aloud before the tone ends. When accuracy holds, stretch to five-letter random groups without writing dots. Pair with Farnsworth at 20 WPM character speed per ITU timing ratios.

Common mistakes

• Calling every long tone M before K is learned — listen for the middle dit in K.
• Studying a printed chart during audio — close visual aids for Koch sessions.
• Slowing dits instead of widening letter spacing.

Session notes

Before lesson 2, log twenty consecutive random copies of K and M without opening a chart. Note whether errors cluster at session start (fatigue) or after distractions (attention). Koch research emphasized full-speed elements because slow sending invites visual counting; if your trainer allows Farnsworth, widen inter-letter gaps only. Compare your notes with the ITU timing description so you know whether mistakes are rhythm or audio setup (volume, sidetone frequency). Share your practice URL in a club thread so others can compare accuracy at the same WPM without sharing scores centrally.

Practice schedule

Days 1–2: ten minutes of K and M only, chart closed. Days 3–4: same pair at the same character speed with a slightly longer gap if you miss the middle dit of K. Days 5–6: twenty random groups, then write the two misses. Day 7: one clean run and stop. Keep the character speed fixed all week.

Koch’s incremental method is described in amateur training literature and summarized alongside Farnsworth spacing on Wikipedia’s Morse code page; timing follows ITU-R M.1677-1.