Monday, December 06, 2010

Radio Panorama RP6: Early Electronic Inventions

When radio was finally invented a hundred years ago, the procedures were very dependent upon other inventions that had already been developed. In this feature item here in Wavescan today, we list half a dozen of these interdependent inventions.
First, we look at the telegraph, a procedure for distant communication whereby the messages were sent along a system of connecting wires. The well known Samuel Morse and his assistant, the almost equally well known Alfred Vail, began working on these matters in the year 1835.
A little more than two years later, on January 6, 1838, Morse & Vail successfully tested their new telegraph system at the Speedwell Iron Works in Morristown New Jersey. One month later they gave a public demonstration of their new telegraph system at the Franklin Institute in Philadelphia, and six years later, they performed their now famous communication epic with a long distance transmission by wire between Washington DC & Baltimore Maryland. Their first message, you will remember, was a statement from the Bible, “What hath God wrought!”
These first messages were all sent in the familiar Morse Code with its system of dots and dashes, but how much better it would be, if voice communication could be developed.
A quarter of a century later, Alexander Bell and Elisha Gray were both working quite independently in the United States on the development of the telephone, and they both unknowingly lodged their patent applications on the same day. However, Bell’s patent application was lodged a couple of hours ahead of Gray’s application, and so the patent for the new telephone was awarded to Bell.
The first ever message by telephone was made by Alexander Graham Bell to Thomas Watson, his assistant, who was working in another room at the time. Bell asked Watson to “come here”. Interestingly, the microphone in use for this first telephone is described as a liquid microphone; that is, a small container containing a weak solution of sulfuric acid with a small metal needle suspended into the liquid.
During the same year that Bell & Watson developed the telephone, another well known inventor, Thomas Alva Edison, developed a carbon microphone that considerably improved the quality of the voice reproduction.
Soon afterwards, Edison went on to develop another significant radio invention, and this was the matter of voice & music recording. Initially, the recordings were made by wrapping tin foil around a cardboard cylinder. The needle at the end of the phonograph horn made indentations into the tin foil, thus recording the sound. However, each playing of the recording damaged the indentations, so that it could be used only a few times at the most. That was in the year 1877.
Eight years later, two other inventors, Chichester Bell & Charles Tainter, developed a wax coated cardboard cylinder that improved the quality of reproduction and could be played many more times before its usability was diminished.
Two years later again, a German migrant to the United States, Emile Berliner, developed the gramophone disc, a flat metal disc covered with shellac. The sound reproduction was greatly improved, and this style was easy to mass produce for sale to the public.
Next came the magnetic recording, and this procedure was developed in Denmark by Valdemar Paulsen around the turn of the century. His Telegraphone, as he called it, made a magnetic recording on a moving wire. The sound reproduction, even without electronic amplification, was more than adequate for headphones and for transmission over the telegraph wires.
At the occasion of the 1900 World’s Fair in Paris, Paulsen recorded the voice of Emperor Franz Josef of Austria, and this is the world’s oldest surviving magnetic recording.
The final invention that we look at today is the electric light bulb. During the latter part of the 1800s, many inventors were working on the development of an electric light bulb. This would replace the arc light that was very noisy, too bright, and very difficult to control.
Over in England, Sir Joseph Swan succeeded in manufacturing an electric light bulb that produced light with the glowing of a carbon filament in a vacuum inside a sealed glass container. Likewise, in the United States, Edison produced a similar light bulb with a carbon filament, though as he stated later, he tested 6,000 different vegetations in his attempts to do so.
In both England & the United States, carbon filament light bulbs went into production. However, a better product was taken into production, when William Davis Coolidge introduced the metal tungsten filament, which is still in use to this day.
Thus, we have investigated the development of half a dozen inventions from a hundred years ago that ultimately found their way into radio:-
* The telegraph system with interconnecting wires gave way to wireless.
* The telephone gave way to the microphone.
* The phonograph & the Telegraphone gave way to tape recordings & computerized recordings.
* The electric light bulb was developed into the radio tube, or valve; and after that, came the transistor.
(WAR Wavescan # 93 via Adrian Peterson)