Introduction To The International Morse Code

Use of the Morse code around the world has diminished significantly, but, it's still in use (and great fun) on the amateur radio bands.

This article introduces the "International Morse Code" as used by radio amateurs. The formal document that describes the "International Morse Code" for use in radio telecommunication is ITU Recommendation ITU-R M.1677-1 (10/2009). While there are extensions to handle languages other than English, we will be concerned with the English language only in this article.

The "International Morse Code" is an aural language. It is decoded from the sounds received by your ears, not by your eyes. It is important to keep this in mind, especially when trying to learn the code. Don't try to memorize dots and dashes. That is guaranteed to slow you down. Instead, say the dits and dahs out loud. Better yet, listen to well formed code being sent. The object of learning the code is to visualize a particular character when you hear a particular sound sequence.

It is also important to realize that the code is made up of two sounds, dits and dahs. it is also made up of the absence of sound, that is, the spaces between dits and dahs. If you ignore the spacing between dits and dahs, you get a very run-on sounding code that is difficult to comprehend. Unfortunately, this is all too common on the air.

The length of the dit and dah sounds and the various spacings are all based on the length of the dit. If the dit sound has a length of one, then the dah will have a length of three dits. Again, with the dit as length of one, the spacing between the dits and dahs within the same character is the same length of one. The space between characters in the same word/group is the length of three dits. The space between words or groups is seven dits.

The ITU Recommendation specifies letters, figures, punctuation, and special signals. This article shows only the first three items. The special signals will be explained in a separate article. There is more information about the sending and receiving of the code contained in the ITU Recommendation. You can find your own copy of the recommendation at https://www.itu.int/rec/R-REC-M.1677-1-200910-I/en.

The International Morse Code