What is Morse Code?
Morse code was invented by Sir Samuel Morse in the late 19th Centuary. It consists of series of Dits and Dashes for each alphabet, number and punctuation marks.
In India, for the ASOC examinations for obtaining amateur radio operator license morse code is a must for Grade I, Grade II and Advanced grade examinations and the Restricted grade is exempted from morse code. Untill the advent of modern day communication system the Morse code was used for telegram, and now also in many places morse code is used for telegrams. The advantage of Morse code compared to voice is that it can reach long distance with very low power due to the fact that only the "Carrier" is transmitted. When the atmospheric condtions deteriorate and voice cannot be effectively reach the destination due to noise, morse code can be used effectively.
Morse code uses the switching ON and OFF of the carrier (or sound) to notify the message. The tables below show the Morse code chart. Morse code is categorized into Alphabets, Numbers and Punctuation marks. For learning Morse Code , the morse code audio tones can be generated using a simple Audio Oscillator using IC 555 timer or a Buzzer, battery and a switch as morse key as shown in the figure.
Morse key is an instrument which is used to generate morse code. Simply, morse key is a switch. The user presses and releases the key for certain durations denoting different numbers, alphabets or puncuation marks. Listen to a sample morse code signal here.
Following figures shows the different types of morse keys used to generate morse code.
Types of Morse Keys
ALPHABETS
| A |
. - |
di-dah |
|
N |
- . |
dah-dit |
| B |
- . . . |
dah-di-di-dit |
|
O |
- - - |
dah-dah-dah |
| C |
- . - . |
dah-di-dah-dit |
|
P |
. - - . |
di-dah-dah-dit |
| D |
- . . |
dah-di-dit |
|
Q |
- - . - |
dah-dah-di-dah |
| E |
. |
dit |
|
R |
. - . |
di-dah-dit |
| F |
. . - . |
di-di-dah-dit |
|
S |
. . . |
di-di-dit |
| G |
- - . |
dah-dah-dit |
|
T |
- |
dah |
| H |
. . . . |
di-di-di-dit |
|
U |
. . - |
di-di-dah |
| I |
. . |
di-dit |
|
V |
. . . - |
di-di-di-dah |
| J |
. - - - |
di-dah-dah-dah |
|
W |
. - - |
di-dah-dah |
| K |
- . - |
dah-di-dah |
|
X |
- . . - |
dah-di-di-dah |
| L |
. - . . |
di-dah-di-dit |
|
Y |
- . - - |
dah-di-dah-dah |
| M |
- - |
dah-dah |
|
Z |
- - . . |
dah-dah-di-dit |
NUMBERS
| 0 |
- - - - - |
dah-dah-dah-dah-dah |
|
5 |
. . . . . |
di-di-di-di-dit |
| 1 |
. - - - - |
di-dah-dah-dah-dah |
|
6 |
- . . . . |
dah-di-di-di-dit |
| 2 |
. . - - - |
di-di-dah-dah-dah |
|
7 |
- - . . . |
dah-dah-di-di-dit |
| 3 |
. . . - - |
di-di-di-dah-dah |
|
8 |
- - - . . |
dah-dah-dah-di-dit |
| 4 |
. . . . - |
di-di-di-di-dah |
|
9 |
- - - - . |
dah-dah-dah-dah-dit |
PUNCTUATION MARKS
| Full stop ( . ) |
. - . - . - |
di-dah-di-dah-di-dah |
| Comma ( , ) |
- - . . - - |
dah-dah-di-di-dah-dah |
| Semi-colon ( ; ) |
- . - . - . |
dah-di-dah-di-dah-dit |
| Hyphen ( - ) |
- . . . . - |
dah-di-di-di-di-dah |
| Question Mark ( ? ) |
. . - - . . |
di-di-dah-dah-di-dit |
| Invitation to Transmit |
- . - |
dah-di-dah |
| Wait |
. - . . . |
di-dah-di-di-dit |
| End of Message |
. - . - . |
dah-di-dah-di-dah-dit |
| End of Work |
. . . - . - |
di-di-di-dah-di-dah |
| Error |
. . . . . . . . |
di-di-di-di-di-di-di-dit |
| Received message |
. - . |
di-dah-dit |
| Separation |
- . . . - |
dah-di-di-di-dah |
