Home Page  People  Things To Do  Glossary  Index  Teacher's Room  Comment Form  Sponsors  Search

"Teaching people about the world in which we live."

Morse Code
by Shawn Steele

Morse code is a system of "dots" and "dashes" used to communicate when voice or other systems cannot be used. The beeps of Morse code were once transmitted by the old telegraph system, and by flashing lights that enabled Navy vessels to communicate. Today, modern amateur radio enthusiasts still enjoy transmitting by Morse code.

In addition to being a fairly international standard, Morse code also has the advantage that it is easier to transmit than sound (voice) signals. Morse code can be sent in a variety of conditions by methods ranging from radio communications, to foghorn sounds, to signal lights and more.

Noisy Morse Code

The following sounds compare Morse code to voice transmissions under a variety of simulated conditions. These sounds contain the same message, but identical amounts of noise have been added to the samples to simulate poor radio reception. In every case the Morse code samples take longer to transmit than the voice samples, but in even the worst of these test conditions the dots and dashes can be heard.

In the first example, an extreme amount of noise has been added to each sample. The voice sample is completely unintelligible, and it is impossible to hear the "beep" part of the Morse code, but the dots and dashes can still be made out.

• Voice with severe noise. (10 KB)
• Morse Code with severe noise. (117 KB)

In the second example, a different amount of noise has been added to both samples. Some of the voice message and the Morse code tones can be heard, but the voice message is not very clear after listening to it only once.

• Voice with some noise. (10 KB)
• Morse Code with some noise. (117 KB)

These are the original samples. Identical amounts of noise were added to these samples to simulate poor radio communications.

• Voice under normal conditions. (10 KB)
• Morse Code under normal conditions. (117 KB)

Those noise conditions are all very interesting, but how often do they occur in the real world? I have a story for an answer. When sailing at the Channel Islands off of California, we found a couple of people that had been involved in an airplane crash. We contacted the United States Coast Guard by voice on the boat's radio to report the crash. Unfortunately, a hill between us and the Coast Guard made radio communication quite difficult. Although we could hear that they were trying to ask us questions, we could not understand them very well. If we had known Morse code we may have had better luck than by sending voice.

How Morse Code Works

Morse code consists of dots and dashes separated by pauses. The dots and dashes can be signaled by any method of making them known to the receiving station, such as by flashing lights, tones on a radio or horns on a ship. Such a light or sound is a dot or dash and the absence of the light or sound is a break between those components.

Dots and dashes are called components. They can be sent at any speed, but a dash must be three times the length of a single dot. Each letter is made up of one or more components (dots or dashes) separated by a pause the same length as a dot. Letters are separated by spaces the same length as a dash, or three dots. Words are separated by spaces the length of seven dots.

The following is a table of the individual letters and symbols used in Morse code. Some of the letters are not used by all languages, and not all languages have an equivalent Morse codes for all of their letters.

Sending Morse Code

You can look up the Morse symbols for any message you would like to send. For example "Hello" would translate to ".... . .-.. .-.. ---" in Morse Code. Notice the groups of dots and dashes for each letter are separated by longer spaces. Remember that each dash is the length of three dots. Each component is separated by a dot sized space and each letter is separated by a dash sized space. Words are separated by longer spaces equal to seven dots.

Morse code is normally sent by beeps of sound or flashes of light, rather than being printed as dots and dashes. You can listen to the phrase "Do you copy?", which is "-.. --- -.-- --- ..- -.-. --- .--. -.-- ..--.." in Morse code.

Practicing Morse Code

Simple Morse Code Buzzer.
Morse Code Telegraph.
Morse Code Lesson Plan.

There is a Java program available to help you learn Morse code.    Learn more about Java and JavaScript.

Morse Code Hints

• Remember that a dash is equal to three dots. If your dash is 3 seconds long, then a dot should be one second. Very quick beeps don't count.
• The spaces between dots and dashes are also as long as a dot. If your dot is a half second long, then your spaces should also be a half second long.
• An easy way to practice dots is to tap a "beat" with one hand and then press or release the space bar each time you tap.
• To time dashes, you can tap 4 times with one hand. Hold the space bar down for the first three taps and release it for the fourth tap. That will give you a three dot sized dash and a dot sized space.

 Home Page  People  Things To Do  Glossary  Index  Teacher's Room  Comment Form  Sponsors  Search