125/₅=25 words in 5 minute; i.e. 5 words per minute.

In fact Morse code devised by Samuel F.B. Morse (1791-1872) is a primitive type of digital communication which still works efficiently in this era of microprocessors and computers. In a computer, all information are processed or stored in binary digits, i.e. 0 and 1s. A zero (0) means that the switch is off and a one (1) makes it on. One interesting fact is that any type of information can be converted to binary digits and later on the information stored in the form of binary digits can be decyphered (decoded).

In the Morse Code system, the encoding is done by 'short' and 'long' duration of flow of current through a circuit. This method of representing and manipulating information in electrical form is known as digital approach, because the encoded information may be visualized as a series of numerical digits. The modern day computer to computer digital communication (which is automated) can be visualised as an extension of the communication system that started with the hand key operated telegraphic communication (which is manual) back in 1837. The computer can sense the 'long' and 'short' pulses and decipher them automatically. But a ham receiving Morse code deciphers the message by listening to the 'short' and 'long' tones. Though the modern day computer communication has its roots in Morse code communication, yet it has been observed that the allocation of Morse codes to the characters has been done in a haphazard manner. It is believed that Samuel F.B. Morse did not visualised his code as a binary sequence. They also believe that Morse did not heard of his now celebrated compatriot George Boole (1854) and his famous work on binary algebra going by his name!

Morse code is also called CW, i.e. Continuous Wave, in the sense that a constant amplitude interrupted radio frequency wave is transmitted; interruption being made in conformity with the code.

Analog and Digital methods

The electrical telephone and telegraph are very simple examples which illustrates the difference between the analog and digital methods. In the telephone, the information is transmitted from one end to the other via a current which varies continuously as direct equivalent of sound waves striking the microphone-the analog approach. In the telegraph, the information is encoded (cyphered) and sent as a sequence of current/no current pulses illustrating the digital approach.

Why Morse code is still in use?

Despite the capability of voice communication, Morse code is still in use. One important reason is that a vast group of the radio amateurs still adore Morse code. A ham radio operator employing digital communication techniques (like Packet Radio, Radio Tele Typing-RTTY or Amateur Tele-printing Over Radio-AMTOR) in his ham radio operation treats Morse code with much the same affection he has for those modern innovations. A ham radio operator wearing his headphone and the Morse Key in hand can send message silently without disturbing family members who are in sleep!

Another reason is that short wave radio telephone (voice) signals often suffer 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 side band may remain strong as a result a continuously readable signal is received. This is the reason that we hear a band full of exotic sounding CW callsigns at any time of day or night. When the a band appears to be dead, and we can barely copy phone signals, the band remains alive with many CW signals.

Why this be so?

(i) The answer is that to communicate human speech, a wider bandwidth is required than that of the CW signal. With a smaller bandwidth the 'signal to noise ratio' of the receiver is significantly improved, and the threshold at which signals can still be received above the noise level is therefore extended.

(ii) Also, it is possible for the human ear to be able to resolve CW signals which are only marginally above the noise level, whereas SSB signals of the same signal level could not be copied. It has been suggested that CW has an advantage of approximately 20dB over SSB signals. A narrow bandpass filter improves the CW reception.

How to learn Morse Code?

Many newcomers seek exemption from 'tiresome' Morse test for Short wave operation. This is unfortunate as the Morse code is the key to enter into the world of ham radio with little monetary investment. A novice can assemble a simple Morse code transmitter with lesser technical hurdles than that of a SSB Voice transmitter. Morse code can be learnt easily if we use certain techniques to remember the codes. Learning the Morse code is also a personal venture embarked upon by alone.

Almost all the letters/characters and puncuation marks can be arranged in certain groups which can used to show the resemblance between/among the combination of dot and dashes. For example the letter 'A' (. _ ) is the opposite of 'N' ( _ . ) in Morse code. Similarly, the letters A, U, V and the character 4 can be made into a group which shows a definite sequence. Given below is a table of such combinations.

EISH   TMO  AN  DU  WG  BV  PX

After remembering the Morse code combination for the EISH combination, the following words can be formed to be sent for receiving practice.

IS HIS SHE

In a similar way, once the novice is able to remember the Morse code combinations for the rest of the combinations shown above, the number of words to be sent can be increased accordingly as shown below.

THIS   TOM  SOME  IT  MISS  THE

MAN  NAME  TEN  NET  HAM

DATE  MAD  SAD  SUN

WHAT  WISH  SAW  WET  WASH  GONE  GOT  HUG

BOSS  TOMB  BOMB  HAVE  VOTE

PET  POT  SHOP  TAX  XEROX

A.G. Reinhold (k2pnk) has devised an innovative method of remembering the Morse Codes by the picturisation of the 'dot' and 'dash' combinations upon each alphabets.