The Theory of Morse Code (CW) Communication
	Samuel Morse was an artist and an American. Unlikely as it may seem, these two factors were responsible for the birth of Morse Code. It was customary for artists and painters of Morse's skill to undertake a "Grand Tour" of Europe. Having previously studied art in England and having exhibited at the Royal Academy, Morse needed little bidding to venture out on such a tour. His inquiring nature led him to attend the exhibitions and lectures of all the disciplines of Art and Science, and it was during his voyage home in 1832 that his thoughts turned to creating a method of effective communication using the newly invented telegraph system. The telegraph grew up alongside the railways. Wires were laid parallel to the tracks with one end connected to a "correspondent" (transmitter) and the other end to a "register" (receiver). Bells would sound at the far end in conjunction with a prearranged code sent from the transmitter. This simple code would consist of a series of rings and pauses to indicate the state of signal settings, the presence of a train, etc. Morse refined the hardware to the point whereby a simple make-or-break lever switch could be used to transmit a code signal, but his first receivers were complex and thus unreliable. An electromagnet was used to push the point of a pencil against a moving strip of paper to record the signal. His first code was a simple number code--the number given to the corresponding alphabetical letter was based on his own localized research into the frequency of use of letters. Thus E equalled 4 as Morse assumed that E was used less often than C, A and R, the letters that he had designated 1, 2, and 3. This early code had to be translated however, and was not a success. In 1838, Morse introduced a letters code known as American Morse which was based on Morse's research into the most frequently used letters used by typesetters and print makers. He determined to use no more than five individual characters to represent a letter or number. This formed the basis of the Morse Code that we know today. By the mid 1850's, the various recording instruments used to receive Morse were replaced by sounders. These sounders were made to reproduce the clicks as sent by the transmitting station, and operators were trained to audibly recognize and copy down the Morse Code. In Berlin in 1851, American Morse Code was modified to incorporate variants that were in use in other parts of the world. This new strain was called International Morse and is virtually identical to what is used today. What is Morse Code? Encoded radio transmissions are the second oldest man-made type of transmission. The first type, unencoded radio transmissions, were created by inducing a spark between two conducting objects, usually two metal hemispheres. These "spark-gap" transmissions were simply continuous rasping white-noise emanations occupying huge bandwidths. Having established communication, attention was turned to encoding the transmissions in some way so that intelligent messages could be transmitted. Applying a high voltage to the spark-gap and then removing it in order to quench the spark resulted in what is now known as CW or Continuous Wave transmission, the carrier being turned on and off in sync with the code being transmitted. This form of transmission is very effective; the full efficiency of the transmitter being employed giving full output on "key down" and no output on "key up." A later variation of CW was MCW or Modulated Carrier Wave, where an on /off audio tone was imposed upon a constantly transmitted carrier. This allowed Morse Code reception by receivers equipped only for AM (Amplitude Modulated) reception. Most transmissions today are manual or automated CW, but some MCW transmissions can still be heard. Whereas transmission of Morse Code is very effective, reception is far less so. The author well remembers having to work a sixteen hour shift in the middle of the Pacific, trying to resolve weak Morse signals amidst the static crashes of tropical storms and the noises of ship's electrical equipment. Reception was, at best, some forty percent of what was transmitted. This is the weakness of Morse Code. History credits Marconi with being the first man to transmit a signal across the Atlantic. Wrong! Anyone can depress a Morse key. Marconi's skills lay elsewhere. He was the first man to receive a signal across the Atlantic, a tremendous achievement given the indifferent quality of the receiving equipment of the time. The human element is still the weak link however.