The telegraphic code used for amateur radio telegraphic communication
is the International Morse Code consisting of
dot (.) and dashes (-).
In International Morse code, a dot is made by
pressing the telegraph key (switch) down and allowing it to spring back again
rapidly; and for making a dash (-), the key is held down for
a bit longer period, that is, not spring back rapidly.
Samual Finely Breese Morse (1791-1872) an American Artist and
Inventor, is credited with the invention of the Magnetic Telegraph and the
means of communication over the telegraph, in 1836. On 24 May 1844, the code
(now called Morse Code) was successfully
tested as a long distance communication medium on an experimental telegraph
line, between Washington DC and Baltimore. Morse himself sent the first
message : "What has God wrought!"
Although Morse's original telegraph system was semi-automatic, telegraph
operators soon discovered that it was possible to aurally distinguish
the symbols being transmitted. The original Morse recording equipment was
eventually discarded in favour of manual transcription. The use of
Morse code as a communications medium has declined since the mid 1920's due to
the introduction of automated telegraph systems, such as teleprinter
and facsimile. Morse code is still in use, due to its superior
performance under extremely poor atmoshpheric
conditions. The main users of Morse Code today are the Maritime,
Military and Amateur Radio Services.
Morse Code is the original Digital Mode dating back to the last
Century! Today, while the debate rages over Morse Code licensing requirements,
more and more stations using this mode have replaced their hand key and their
electronic keyer with a Computer keyboard and display. The technology is good
but even today, no machine can beat the trained human ear for copying hand
sent Morse Code under varying conditions. The keyboard is a more efficient
Sending device though, for most people. Perhaps the one advantage of Morse
over Packet and the others, is that a human operator can decode the Morse Code
transmissions by ear!
To get your amateur radio license from
the Ministry of Communications, you need learn Morse code.
To learn Morse code you need an electronic device called the
'Code Practice Oscillator' (CPO). It
is an audio frequency generator which produces an audible tone. Radio amateurs
while learning Morse code never try to memorize them as 'dot' and 'dashes' by
mere visualization of the 'dot' (.) and 'dashes' (-); but they
try to memorize them by hearing the tone and thus for easy remembering of the
combination of codes they say dot and dash as di and dah
respectively. The different combination of di and dah make the
alphabets, figures, characters and punctuation marks.We refer to dot and dash
as di and dah as that how you hear the sound and pronounce them as. The
time taken to produce the sound equivalent to one di or dit
(dot) is taken as unit time and called a dot unit.
and the space between two sound elements of a letter is one
dot unit (silence period is one dot unit).
A dah (dash) is approximately of three dot units length
The space between two letters or characters is equal to three dot units.
The space between two words is equal to five dot units. It all depends on
your imagination and experience gathered listening to Morse code
transmissions over your radio or from a pre-recorded cassette player.
Learning to send Morse code using a Morse
Key is far more easier once somebody demonstrates it to you. But it
is a bit difficult to learn decoding of incoming Morse signals; yet to be a
skilled Morse sender, it is said that you should first learn decoding
(decipher) of Morse code from a pre-recorded cassette or the
software provided here which can be
downloaded free of cost.
While appearing for the
Amateur Station Operator's Certificate Examination,
you can go for a 5 word per minute speed (for Grade-II license) or for a
12 word per minute speed (for Grade-I & Advanced Grade license).
to measure your speed ? (5 Suppose a written message containing
125 letters when sent in 5 minutes makes a speed of 5 words per minute (for 5
letters makes a standard word).
125/5=25 words in 5 minute; i.e. 5 words per minute.
THE INTERNATIONAL MORSE CODES
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||. _ . _ . _ (AAA)
||_ _ . . _ _ (MIM)
|Question Mark (?)
||. . _ _ . . (IMI)
||_ . _ . _ . (NNN)
||_ . . . . _ (BA)
||. . . . . . . .
||_ . . . _ (BT)
transmission of a message
||. _ . _ . (AR)
||_ . _ (K)
||. _ . . . (AS)
|End of work
||. . . _ . _ (VA)
Once you get your license and the callsign, it is time for you to
The general call is known as the 'CQ' call inviting reply from
any on-the-air station. It is not a directional call. Directional call is
given to a definite station or definite country.
CQ CQ CQ DE VU2XYZ VU2XYZ AR K
VU2XYZ DE 4S7VK AR KN
A typical format a ham radio operator's message during Morse Code
communication when contacting another ham radio operator for the first time
may look like :
4S7VK DE VU2XYZ BT TNX FER CALLING ME BT UR RST IS 579 BT MY NAME IS
...............ES QTH IS ...............BT AR 4S7VK DE VU2XYZ KN
In the above message station 4S7VK is being replied back by station
VU2XYZ with an exchange of signal report
and his name and location. In Morse Code transmissions,
abbreviations are used instead of the complete word or sentence
The question arises why Morse code is still used for radio communication? The
reason is that Short-Wave radio signal in radiotelephone (voice
transmission) is often subjected to very rapid and deep fading; two
frequencies separated by only a few Hertz, fade at different times. To
overcome this, modulated code tones are transmitted. The situation is now that
under severe conditions of fading, the carrier frequency may fade out
completely but one or the other sideband may remain strong, as a result a
continuously readable signal is received. With power as low as 5 watts you can
expect to contact an amateur radio station located on the opposite side of the