We recommend you to use the same visualization techniques as the memory masters, which can learn the complete order of all the playing cards in a deck of cards in just a few minutes. In our case we would like to learn the Morse code for about forty characters. Then we should visualize one picture for each character, and that picture should in some way connect the character with the corresponding Morse code.
Consider the top two example pictures below. The first picture shows a “hippo”, which connects the letter H with the Morse code of H “dot dot dot dot”. The second picture shows a “mustache”, which connects the letter M with the Morse code of M “dash dash”. These example pictures are taken from morse.withgoogle, where you can find a training tool with such pictures for all characters you need to know. However, it is even better if you create your own pictures. The Morse codes of all characters can be found in wikipedia. You do not have to draw the pictures, it is enough that you visualize them in your head. Your visualizations are easier to remember if they are large, colorful, emotional and preferably a little weird.
Consider the two bottom images above. These pictures are more abstract but they also connect a character with its corresponding Morse code. We recommend that you create both the first type of more real pictures, and the second type of more abstract pictures, to connect each character with its Morse code in two different ways. Then, if you happens to forget one picture there is a good chance that you remember the other one.
You can practice by using the training tool at morse.withgoogle, using some Morse training app, or just visualize the pictures for each character in your head over and over again. The important thing is that each time you want to recall the Morse code of a character, or the character of a Morse code, you should do it by visualizing the corresponding pictures.
After practising just a few hours, most people have learned the Morse code of all characters they need (letters, digits and the most common punctuation symbols). Let us know if this technique worked for you!