📡 Radio From Scratch

About Morse Code

Morse code is a system for converting text into a code that can be easily transmitted over radio. It is also sometimes called CW for “continuous wave”, which will make more sense in a moment.

How Morse code works

Morse code describes how to turn English letters and numbers into a series of short and long pulses. Short pulses are sometimes called dots or “dits”, and long pulses are sometimes called dashes or “dahs”.

Senders and receivers use the Morse code alphabet to convert between text characters and the dots and dashes of the code.

Additional spacing is used between letters, and between words. Convention is to use the length of a dot as the basic time unit. The duration of other symbols is based on this time.

symboltime units
between symbols1
between letters3
between words (written /)7

Morse code equipment

Typical Morse code hardware usually consists of a radio, a speaker, and a “key”. This key is essentially a button that turns on and off the broadcast. When the key is down, a continuous wave or unmodulated carrier frequency is broadcast. When it is off, there is no signal.

While Morse code is often used for sending text over radio, it is sometimes also used with flashes of light, or any medium where you can easily have two different types of pulse.

Morse Code Alphabet

Below is a table which includes the most common morse code symbols.

Letter Symbol Letter Symbol

Morse code example

Let say we want to send the message “hello there”. After converting to Morse symbols, our message is:

.... . .-.. .-.. --- / - .... . .-. .

Why use Morse code?

Though official usage of Morse code has declined, it is still a popular choice for radio hobbyists. Why? Once learned, recognizing the symbols becomes automatic, just like reading. Morse code opens up the possibility of long distance communication over a wide variety of media, including radio, sound, and light.

Additionally, there is a sort of magical feeling from being able to build a device that enables such long distance communication easily. Licensed HAM radio operators have successfully achieved contact at distances of 1000 km using CW.

The simple tone can be easily recognized by ear despite interference, making it a particularly resilient way of communicating.

How to learn Morse code?

The most effective way to learn Morse code is by learning to recognize the sounds. Many techniques focus on memorizing the symbols, but this way of learning fails to work for higher speeds. You want to make the recognition automatic, just like hearing sounds in your native language.

The Farnsworth method refers to the technique of playing symbols at full speed, but increasing the spacing between letters based on your experience level. This way you are practicing listening at a realistic pace without worrying about getting overwhelmed.

On top of this, the Koch method refers to learning with a reduced set of letters. More letters are added as you gain confidence with what you’ve learned so far.

An effective tool for learning Morse code in this way can be found a LCWO (Learn CW online)

Our other Morse code tools

  • Morse Chat (create and send Morse code messages online)

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