notes.dt.in.th

How I memorize the morse code

I set up my phone to vibrate in morse code so I can tell apart different kinds of notifications without having to pick up my phone. Inside my pocket, I can feel the vibration. Outside the pocket, I can hear the sound of vibration.

Because of that, I need a way to learn the morse code. I could use an app to practice deliberately, but I’m too lazy for that. On YouTube there are many memorization techniques ([1], [2]) and the morse code binary tree chart is also very helpful, but there’s one more trick that I did not see it in any of these videos, but helped me a lot. I’ll share it here.

I still can’t decode morse code fast yet1, but I’ll share it anyways as it really helps me with accuracy. For me, the trick is to memorize this set of 2-to-3-character sequences:

EIA ISU SHV UF ARW RL WPJ TNM NDK DBX KCY MGO GZQ

No need to remember them in order — just memorize enough to be able to recall the sequence given the 1st character. For example, if I think of U, then I should be able to recall UF. Use any mnemonic you like. For example, for UF I just think about the sound “oof!”

In each sequence…

  • The 1st character is the parent node of the binary tree.
  • The 2nd character is the left child and represents a dit ..
  • The 3rd character (if present) is the right child and represents a dah -.

…and together, they form the morse code binary tree. Remembering these 3-character sequences enables efficient access to the relevants part of the tree.

Also remember:

  • The first dit . is E.
  • The first dah - is T.

Decoding

Let’s look at an example:

  1. I hear a morse code, .--..
  2. I remember that the first . is ‘E’.
  3. I recall EIA, so .- is ‘A’.
  4. I recall ARW, so .-- is ‘W’.
  5. I recall WPJ, so .--. is ‘P’.

This looks like a lot of steps. However, as I decode more morse codes, shortcuts begin to form in my brain. For example, when I hear .-, I immediately think of ‘A’.

Here’s one more example of decoding with shortcuts:

  1. I hear a morse code: .-..
  2. I remember that .- is ‘A’.
  3. I recall ARW, so .-. is ‘R’.

I’m not there yet, but I hope that at some point, these shortcuts would turn into a complete mental lookup table, so I can decode each character in a single mental step.

Encoding

Now here’s one weird thing. Once I had the lookup table memorized, it seems that not only can I recall the sequence from the 1st character, but also from the 2nd and 3rd character — it’s as if my brain automatically built an index for the 2nd and 3rd characters as well. Not sure if this happens to everyone though.

Let’s say I want to encode ‘W’.

  • First, WPJ comes up to my mind, but it’s irrelevant.
  • Next, ARW came up. ‘W’ is in the 3rd position, so I know it ends with - and its parent is ‘A’.
  • Next, EIA came up. ‘A’ is in the 3rd position, so before that - there’s another -.
  • I remembered E is ..
  • Putting them together, the morse code for ‘W’ is .--.

Footnotes

  1. I still cannot decode a sequence of morse code in real-time. I hear a sequence and have to think about it for a few seconds before I can decode it.