Everything You Need To Know About Morse Code

Morse code is a process for transmitting telegraphic information, utilizing standardized series of short and long elements to illustrate the letters, numerals, punctuation, and specific characters of a message.

The short and long pieces can be formed by sounds, marks, or pulses, in on-off keying and are commonly known as "dots" and "dashes" or "dits" and "dahs." Morse code can be obtained in several ways: originally as electrical vibrations along a telegraph wire, but also as an audio tone, a radio signal with short and long tones, or as a computerized or visual signal (for example, a flashing light) using instruments like an Aldis lamp or a heliograph.

Morse code is communicated using just two states (on and off) so it was an earlier form of a digital code. However, it is technically not binary, as the pause lengths are required to decode the transmission.

Created for Samuel F. B. Morse's electric telegraph in the 1840s, the Morse code was also considerably utilized for early radio transmission forming in the 1890s.

For the first half of the twentieth century, the majority of high-speed international transmission functioned in Morse code, utilizing telegraph lines, undersea cables, and radio circuits. However, the varying length of the Morse characters made it hard to adapt to automated circuits, so for the most electronic transmission, it has been replaced by more machinable forms, such as Baudot code and ASCII.

The use of the Morse code revolutionized international communication. The ability to utilize a visual signal also meant that Morse code could be operated to exhibit distress and the need for help, whether from a lifeboat at sea or an isolated land location (signaling a searching rescue aircraft).

Over the years, Morse has been used in inter-governmental transmission, in commerce, and in times of distress, it has allowed making war but also peace. Its benefit is increasingly a matter of historical interest but few would dispute that it has contributed to human transmission of incalculable value and significance.

Morsecode Language: Main Elements

International Morse code is comprised of six elements:

  1. short mark, dot, or 'dit' (·)
  2. longer mark, dash, or 'dah' (-)
  3. intra-character interval (between the dots and dashes within a character)
  4. short gap (between letters)
  5. medium gap (between words)
  6. long gap (between sentences — about seven units of time)

These six elements serve as the base for the International Morse code and therefore can be utilized for the use of Morse code worldwide.

International Morse code : Amateur radio

International Morse code today is most popular among amateur radio operators, where it is used as the pattern to key a transmitter on and off in the radio transmissions mode typically directed to as "continuous wave" or "CW."

The original amateur radio operators used Morse code only, as voice-capable radio transmitters did not become typically available until around 1920. Until 2003 the International Telecommunication Union (ITU) mandated Morse code command as part of the amateur radio licensing procedure worldwide.

However, the World Radio communication Conference of 2003 (WRC-03) made the Morse code essential for amateur radio licensing optional. Many countries thereafter removed the Morse requirement from their license requirements.

Until 1991, a demonstration of the power to send and acquire Morse code at five words per minute (WPM) was required to receive an amateur radio license for use in the United States from the Federal Communications Commission.

Demonstration of this power was still required for the privilege to use the HF bands. Until 2000, ability at the 20 WPM level was needed to obtain the highest level of amateur license (Extra Class); effective April 15, 2000, the FCC decreased the Extra Class essential to 5 WPM.

Finally, useful February 23, 2007, the FCC eliminated the Morse code proficiency needs for all amateur licenses. While phone (voice) and data transmissions are restricted to precise amateur radio bands, CW is the only form of communication that is permitted on all amateur bands—LF, MF, HF, UHF, and VHF. In some countries, certain portions of the amateur radio bands are reserved for communication of Morse code signals only.

Because Morse communications employ an on-off keyed radio signal, it requires less complex equipment than other forms of radio communication. Morse code also requires less bandwidth than voice transmission, typically 100-150 Hz, corresponding to the roughly 2400 Hz used by single-sideband voice.

Morse code is acquired as a high-pitched audio tone, so transmissions are easier to copy than voice through the noise on congested frequencies, and it can be used in very high noise / low signal environments.

The fact that the transferred energy is concentrated into a very limited bandwidth makes it possible to use narrow receiver filters, which suppress or eliminate interference on nearby frequencies.

The narrow signal bandwidth also takes benefits the natural aural selectivity of the human brain, further improving weak signal readability. This efficiency creates CW extremely good for DX (distance) communications, as well as for low-power messages (commonly called "QRP operators," from the Q-code for "reduce power").

Several amateur clubs need a solid high-speed copy, the highest of these has a standard of 60 WPM. For a lower level, the American Radio Relay League offers a code ability certification program that starts at 10 WPM.

The somewhat limited speed at which Morse code can be sent led to the outcome of an extensive number of abbreviations to speed communication. These contain pro signs and Q codes, plus a limited standardized format for typical messages.

This usage of abbreviations also boosts transmission between operators who do not share a common language and thus would have great difficulty in transmitting using voice modes.

Although the standard telegraph key (straight key) is still used by many amateurs, the use of semi- and fully-automatic electronic keyers (known as "bugs") is dominant today. Computer software is also continuously employed to create and decode Morse code radio signals.

Use Morse Code With Light

You never know what strange situations you'll find yourself in one day, nor what unusual and seemingly worthless skills could help you in those situations. You never understand what skills could one day save your life. But is blinking Morse code with a light of those evasive skills, and is there any advantage to learning it?

Using light for Morse code is very simple. Dots are depicted with short bursts of light, while dashes are displayed with longer beams. Conveying Morse code with light delivers line-of-sight security, suggesting only those that can see the light can obtain the communication. A real-world example is the US Navy ships that utilize signal lamps to communicate during radio silence. So let's look at how to utilize Morse code with light and how you can operate it to send and obtain your line-of-sight transmissions!

Morse Code with Light: The Basics

The first step in understanding how to use Morse code with light is learning the basics of Morse code and then learning how to translate that to light signals! So let's start with the basics and if you would like a more in-depth dive into understanding Morse code, check out How to Understand and Use Morse Code.

The Dots and Dashes

The whole Morse code system is constructed using two different symbols: the dot and the dash. The dot symbolizes a short and short signal that is commonly described as the sound "di."

On the other hand, the dash represents a more extended signal and is three times longer than the dot. 

Dashes are generally expressed as the longer sound "dah." Said another way, the timing difference between dots and dashes is a 1:3 ratio. You can listen to the difference between a dot and a dash utilizing the sound clip below.

By mixing these dots and dashes into differing varieties, we can create letters, numbers, punctuation, and special characters.

For example:

  • Morse code for the letter A is • ─
  • Morse code for the letter B is ─ • • •

So how do we communicate these two symbols utilizing light?

Remember how we said that dashes were three times more extended than dots? We're going to utilize these timing rules using light.

  • To symbolize dots, turn your light on for 1 second. 
  • To symbolize dashes, turn your light on for 3 seconds. 

You can, of course, adjust the timing to meet your needs and skill, but remember to maintain the ratio of 1:3 between dots and dashes.

Match out the two videos below to see the difference between dots and dashes.

Morse code as an assistive technology

Morse code has been employed as assistive technology, helping people with a variety of disabilities to communicate. Morse can be transmitted by persons with severe motion disabilities, as long as they have some minimal motor control.

In some circumstances, this means alternately blowing into and sucking on a plastic tube ("puff and sip" interface). People with intense motion disabilities in addition to sensory disabilities (e.g. people who are also deaf or blind) can acquire Morse through a skin buzzer. Products are unrestricted that allow a computer operating system to be controlled by Morse code, letting the user access the Internet and electronic mail.

In one case conveyed in the radio amateur magazine QST an old shipboard radio operator who had a stroke and lost the power to speak or write was able to convey with his physician (a radio amateur) by blinking his eyes in Morse.

A better-confirmed case happened in 1966 when American prisoner of war Jeremiah Denton, obtained on television by his North Vietnamese captors, Morse-blinked the word TORTURE.