Morse Code

Morse Code

Morse code is a type of character encoding that transmits telegraphic information using rhythm. Morse code uses a standardized sequence of short and long elements to represent the letters, numerals, punctuation and special characters of a given message. The short and long elements can be formed by sounds, marks, or pulses, in on off keying and are commonly known as "dots" and "dashes" or "dits" and "dahs". The speed of Morse code is measured in words per minute (WPM) or characters per minute, while fixed-length data forms of telecommunication transmission are usually measured in baud or bps.

Originally created for Samuel F. B. Morse's electric telegraph in the early 1840s, Morse code was also extensively used for early radio communication beginning in the 1890s. In the early part of the twentieth century, the majority of high-speed international communication was conducted in Morse code, using telegraph lines, undersea cables, and radio circuits. However, the variable length of the Morse characters made it hard to adapt to automated circuits, so for most electronic communication it has been replaced by machine readable formats, such as Baudot code and ASCII.

The most popular current use of Morse code is by amateur radio operators, although it is no longer a requirement for amateur licensing in many countries. In the professional field, pilots and air traffic controllers are usually familiar with Morse code and require a basic understanding. Navigational aids in the field of aviation, such as VORs and NDBs, constantly transmit their identity in Morse code. Morse code is designed to be read by humans without a decoding device, making it useful for sending automated digital data in voice channels. For emergency signals, Morse code can be sent by way of improvised sources that can be easily "keyed" on and off, making Morse code one of the most versatile methods of telecommunication in existence.




Morse Code can be transmitted using sound or light (a signalling system that uses combinations of long and short sounds, flashes of light or electrical pulses), as sometimes happens between ships at sea. It is used in emergencies to transmit distress signals when no other form of communication is available. The standard international distress signal is •••---••• (SOS)

A sailor using light flashes to send morse code messages


A typical "straight key." This U.S. model, known as the J-38, was manufactured in huge quantities during World War II, and remains in widespread use today. In a straight key, the signal is "on" when the knob is pressed, and "off" when it is released. Length and timing of the dots and dashes are entirely controlled by the operator.


Vibroplex semiautomatic key (also called a "bug"). The paddle, when pressed to the right by the thumb, generates a series of dits, the length and timing of which are controlled by a sliding weight toward the rear of the unit. When pressed to the left by the knuckle of the index finger, the paddle generates a dah, the length of which is controlled by the operator. Multiple dahs require multiple presses. Left-handed operators use a key built as a mirror image of this one.




LEARN MORSE CODE in one minute!
This is a code listening tool. Print it on your printer.
Place your pencil where it says START and listen to morse code.
Move down and to the right every time you hear a DIT (a dot).
Move down and to the left every time you hear a DAH (a dash).
Here's an example: You hear DAH DIT DIT which is a dash then dot then dot.
You start at START and hear a DAH then move down and left to the T and then you hear a DIT so you move down and RIGHT to the N and then you hear another DIT so you move DOWN and RIGHT again and land on the D
You then write down the letter D on your code copy paper and jump back to START waiting for your next letter.
The key to learning the code is hearing it and comprehending it while you hear it.
The only way to get there is to practice 10 minutes a day.
Listen to code tapes or computer practice code while tracing out this chart and you will find yourself writing down the letters in no time at all without the aid of the chart.
The chart brings repetition together with recognition, which you don't get from any other type of code practice aid.






Other methods to remember:




Another morse code tree, reverse (mirror image) of the one above


A graphical representation of the dichotomic search table: the user branches left at every dot and right at every dash until the character is finished.