How to communicate with Morse code (using visual, audio, andpressure forms of communication)

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About Morse Code

Morse code (not “Morris code”) is a method of transmitting textual messagesusing a series of patterns.  Each text unit in the pattern can be represented (orreproduced) using on-off tones (sound), flashing lights, or clicks representing“dots” and “dashes” (known as dits and dahs).  The traditional Morse codeencodes the 26 Roman letters but extensions have been added to allow forrepresentation of non-English languages and a small set of punctuation andprocedural signals.

To improve efficiency and transmission speed, Morse code was designed so thatthe length of a character in Morse varies inversely with its frequency of use in theEnglish language.  For example, the letter “E” is the most used character in theEnglish language and is represented by the shortest possible Morse code – asingle dot.

Interestingly, individual Morse code operators differ slightly, for example usingslightly longer or shorter dashes or gaps, perhaps only for particular characters. This is called their “fist”, andexperienced operators can recognize specific individuals by their fist alone. A good operator who sends clearly andis easy to copy is said to have a “good fist”. A “poor fist” is a characteristic of sloppy or hard to copy Morse code.

Using Morse Code

Morse code using audio tones

Morse code can be transmitted in a number of different ways.  Originally designed to be used as an electrical pulsealong a telegraph wire, it can easily be represented as an audio tone.  Used as an audio signal, Morse code can betransmitted via a radio signal with short and long tones or even the sound of a car horn.  In survival situations,Morse code can be produced via the banging of pots and pans or knocking loudly on a hollowed log.

Morse code using visual cues

Morse code is commonly transmitted as a visual signal using flashing lights or reflections but can also be used as anon-detectable form of communication using the tapping of fingers or even blinking of eyes.

Using just two states (on and off), it is a form of digital code and can also be represented using 1’s and 0’s.  Forexample, a Morse code sequence may be made from a combination of the following five bit strings:

1. short mark, dot or “dit” (·) : 1

2. longer mark, dash or “dah” (–) : 111

3. intra-character gap (between the dots and dashes within a character) : 0

4. short gap (between letters) : 000

5. medium gap (between words) : 0000000

Morse code using touch or pressure

Finally, Morse code can be transmitted using touch or pressure.  For instance, some miner rescues have used tugsof a rope as a means to transmit Morse code to an injured miner.

How to communicate using Morse Code

Each Morse code character is represented by a unique sequence of dots and dashes.  A dot (or dit) represents asingle unit whereas a dash (or dah) is three times the duration of a dot.  Each dot or dash is followed by a shortsilence equal to one dot.  Letters in a word are separated by silence equal to three dots (one dash) and words areseparated by seven dots of silence.

1. Dot – one “dit”

2. Dash – three dits or “dah”

3. Space between letters – three dits of silence

4. Space between words – seven dits of silence

Learning to receive Morse code

The easiest way to learn Morse code is to find Morse code recordings, listen to them, and work out the encodedmessage on paper.  While learning, do not get into the habit of counting the dots and dashes in the Morse code. Instead, learn to recognize the sound of each letter. If using a software application that helps train you in Morsecode, never slow down the letter speed but rather, only slow down the letter spacing.

A dichotomic search tree can be used as a means to improve speed too (see example in the gallery).  Using adichotomic search tree, each time you hear a dit (short beep) you move down and to the left on the tree.  Each timeyou hear a dah (or long beep), you move down and to the right.  Practice with a dichotomic search tree candramatically improve your Morse code transmission speed.

Another option when receiving Morse code is to simply jot down the dots and dashes and then use a chart(download below) to decode the Morse code message.  “Pros” however, will point out that this effectively doublesthe time is takes to decode the message.

Learning to transmit Morse code

Practicing Morse code can be done in your head or using the buttons on a smartphone device to produce audioMorse code tones.  Pick a word you wish to transmit and hear the sound in your head.  Dit is pronounced “di” with ashort “I” and silent “T”.  Dah is pronounced with a short “A” sound.  Thus, “cat” would be pronounced dah-di-dah-di di-dah  dah.  Again, hear the code in your head.  The letter “C” in cat sounds like dah-dit-dah-dit (long short longshort).  In Morse code, cat would look like this:

When transmitting, pay particular attention to your spacing.  Each letter should be separated by aspace equal to the same duration as a dah (three times the duration of a dit).  Each word shouldbe separated by a space that lasts about seven times the duration of a dit.  The better yourspacing, the easier your code will be to understand.

Morse code tips

It helps to know the number of dits and dahs in each letter.  This will help you narrow down the possibilities whenyou receive a Morse code encoded message.

T, E= 1 character each

A, I, M,N= 2 characters

D, G, K, O, R, S, U, W= 3 characters

B, C, F, H, J, L, P, Q, V, X, Y, Z= 4 characters each

Morse code examples

Below are Morse code examples which may help you visualize the encoding/decoding of Morse code into its textualrepresentation.

Dog

Survival

SOS

Need water

Taking fire

Danger ahead

Basic Morse code

The chart below contains the complete International Morse code.  Downloadable versions of the chart are availablein the gallery below.  In the charts, a dash is equal to three dots in time, while the interval between the dots anddashes in a letter equals a dot in time.  Between the letters in a word the interval is equal to three dots and betweenwords, five dots.

Morse code Q-Codes

Q-codes are standard three-letter message encodings often used in Morse code communication.

Morse code phrases

Other abbreviations are commonly accepted in Morse code communications including the list below.

Gallery of Morse Code charts

Below is a gallery of Morse code charts.  Click the diagram and then right click to save a copy.