What is Morse Code?

Clara Crockett

A Morse code is a telegraphic system in which letters, numbers, punctuation, and special characters are represented by standardized sequences of short and long elements.

Short and long elements can consist of sounds, marks, or pulses when off-keying; they are commonly referred to as "dots" and "dashes". You can find an alphabet list in Morse code by clicking on the image to the left.

The History of Morse Code

The Morse code was developed for Samuel F. B. Morse's electric telegraph in the 1840s, and it was also extensively used for early radio communication, beginning in the 1890s.

As a result of telegraph lines, undersea cables, and radio circuits, Morse code was used for the majority of high-speed international communication during the first half of the twentieth century. Because Morse code characters can vary in length, it is hard to use on automated circuits. For most electronic communication, Baudot code and ASCII are used instead, which are easier for a machine.

How is Morse Code Used Today?

Amateur radio operators are the most popular users of Morse code today. However, while most countries no longer require Amateur licenses, they continue to use them for specialized purposes, such as identifying navigational radio beacons and land mobile transmitters, as well as for military communications, such as flashing semaphores between ships in some naval services.

As the only digital modulation mode that can be read by humans without a computer, Morse code is perfect for sending automated digital data over voice channels as well as for emergency signaling, such as using improvised energy sources that are easily "keyed," as in supplying and removing electrical power (e.g., by turning a breaker on and off).).

SOS Morse Code

Help in Morse Code - What does SOS Stand For?

There was no original meaning for SOS; the phrase was a way of guessing what it meant. It could mean any of these things: "Save Our Seamen", "Save Our Ship", "Survivors On Shore", "Save Our Souls" or "Save Our Selves". In reality, it was used because the letter S and O are easy to write and distinguishable.

A distinctive feature of the letter S is its three dots (...), and a distinctive feature of the letter O is its three dashes (---). Click on the image above for a list of the rest of the Alphabet in Morse Code.

In international Morse code, six elements are used:

  • short mark, dot, or 'dit' (·)
  • longer mark, dash, or 'dah' (-)
  • intra-character gap (between the dots and dashes within a character)
  • short gap (between letters)
  • medium gap (between words)
  • long gap (between sentences — about seven units of time)

International Morse code consists of these six elements; therefore, it can be used worldwide.

How is Morse Code Transmitted?

The Morse code was originally transmitted by electrical pulses along telegraph lines, but it is also available as an audio tone, as a radio signal that is short or long, or as a mechanical signal (e.g. flashing light) utilizing devices like an Aldis lamp or a heliograph (e.g. a flashing light).

The Morse code uses just two states - on and off - so it was an early form of digital communication. Although it is technically not binary, the pause lengths are necessary for decoding.

How Long is a Dot and a Dash?

The dot/dit duration is used as the basic unit of time measurement when it comes to Morse code transmission. Dashes and dashes have a three-times longer duration than dots and dits. In other words, the signal for the dash/dah should be present for three times the length of time that the sender takes to make a dot/dit.

Gaps Between Letters, Words, and Sentences

Tapping or flashing letters to transmit messages is one thing, but being able to write out words and sentences is essential for a message to make sense. In that case, all the receiver will receive is one long block of text.

The gaps between letters, words, and sentences are short, medium, and long, respectively.

Whenever a dot/dit or dash/dah appears in a letter or number (or another character), it is followed by a period of silence called a space. During this space, the receiver is informed that the Morse code for that particular character has ended and the next signal to be received will be the start of the next letter.

Why is this important? Let's look at the letters S, T, and V using the Morse code chart above. An operator wouldn't know if the three dots and a dash were the letters S and T if there weren't pauses between letters, or if they were all part of the same letter (V, which is composed of three dots and a dash).

Three dots/dits separate the letters of a word, and seven dots/dits separate words. Thus, a readable message can be understood by distinguishing between letters and words.

Morse Code Alphabet

You can view the Morse code chart image above as well as the complete Morse code alphabet in the table below:

Morse Code Numbers

The table below shows numbers that are represented by Morse code as well as the Morse code chart image above:

Morse Code Characters and Symbols

You can also view Morse code characters and symbols in the table below, in addition to viewing the Morse code chart image above:

Morse Code to English and How to Read Morse Code Quiz

Let's check your understanding of Morse code reading and writing now that you have learned how to decipher and transmit Morse code from and into English.

Clara Crockett
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