AT&T Archives: The Far Sound, a History of Long and Longer Distance Communications, from 1961

I believe in the future wires will unite different cities and a man in one part of the country may communicate with another in a distant place when Alexander Graham Bell wrote those words in 1878 he foreshadowed the basic problems for all future research in communication even though at the time the telephone itself was only two years old a man in one part of the country may communicate with another in a distant place first research had to meet the challenge of getting man's voice clearly to that distant place the problem of transmission it was of course the miracle of the telephone that made possible the transmission of speech by transforming the speaker's voice into electrical waves hello to be changed back to sound waves at the other end of the wire but over long distances the voice gradually faded away how are you despite that fact by 1912 a man in New York could talk into a telephone talk louder and with the aid of various devices he could be heard more or less distinctly in Denver but without something to strengthen voice signals along the way that seemed about as far as people could talk then came the Audion vacuum tube invented by dr. lee deforest with continued research and development dr. Harold Arnold of Bell Telephone laboratories improved the original design to obtain a better vacuum the new tubes enabled engineers to build amplifiers which were effective voice boosters at last it was possible to complete the line from coast to coast 1915 the first transcontinental telephone line made front-page news but there were still telephone men who knew the job had only started it's a great accomplishment nobody can doubt that all of you men have talked over this so-called transcontinental line just as I have by the time my voice hits Frisco I sound like Jenny Lind or vice versa not only where she was funnier one of the really rough problems is those vacuum tube amplifiers each one we use on the line adds its own distortion to the conversation you're right the amplifiers are our problem by the way do any of you men know what the word telephone really means it's from two greek words meaning far and sound and i would say that if we had one main job all of us it is to make darn sure that the forest sound isn't far so we have got to improve those amplifiers I don't know at twenty two dollars for one three-minute call I'm not sure that public is going to so jump over itself to call Costa don't you believe it the way this country is drawing of the plenty of people who want to call once we get the cost down the problem is held well I know one way personally I feel in the year 1915 it is a waste of our customers money for one pair of wires to carry only one conversation you know we've been working on that carrier idea but it's still a long way from being good enough well we've got to make it good enough we'll need a carrier system that will send at least five conversations on five conversations on one line impossible not at all three years later in 1918 five individual conversations could be transmitted on one pair of wires with an improved carrier system how did it work well carrier transmitted a far wider band of frequencies on one pair of wires than a single conversation required the extra conversations hitchhiked along those frequencies without interfering with one another at the other end the conversations were filtered apart and said on to their separate destination carrier was a big step toward better service at lower cost but with more and more conversations on one line the problem of distortion had to be solved a voice going across country by carrier which started out in San Francisco sounding like this hello was apt to arrive in New York sounding more like this as the years passed men sought ways to free the far sound from such distortion finally in 1927 a young telephone scientist named Harold black made use of the fact that an amplifier would distort a voice signal Blatt took a small fraction of that distorted voice signal and put it through a feedback circuit to reverse the distortion the reversed voice signal was put back into the amplifier thus the very tendency of the amplifier to distort now produced a signal that was almost distortion free know the feedback principle worked with so many voices at once but more conversations than ever before could now be tied clearly on a single line but still beyond a certain limit extremely high frequencies would fade out as though Nature herself had said thus far no farther but scientists and engineers have a way of confounding nature in their struggle to bring the far sound near they conceived the idea of enclosing a single wire inside a copper tube to provide a protective pathway for conversations this was coaxial cable each one of those early tubes carried 200 conversations at one time the inventors of coaxial have long since retired from active work at the laboratory but their remarkable achievement in creative thinking was the basis for further research and development that resulted in cables that can carry nearly 2,000 conversations in every pair of copper tubes what's more the laying of the first coaxial cable in 1936 meant that television networks could be established throughout the country as they were after the war when towers rising across the land made network television even more practical and provided another way to carry telephone conversations distant places radio relay was an outgrowth of earlier research in radio and radar radar transmitted high-frequency radio waves when some of them struck a distant object they were reflected back to highly sensitive antennas like radar microwave radio relay also transmitted very high-frequency radio waves but research found a way to now the beam and aim it with great precision toward a receiving antenna on the distant horizon that beam like an invisible wire through the air served as carrier to transmit first nearly 500 conversations then 1,200 and then 1800 conversations at once racing from tower to tower and speed of light however some frequencies were so high that rain and snow interfered with them once again it seemed as if nature could limit man's progress in bringing the far sound near but even as far back as the early 1930s dr. George Southworth now retired had been experimenting with the transmission of high frequencies through hollow pipes called wave guides recent tests promised that these experimental wave guides may be able to transmit 200,000 telephone conversations at one time 200,000 voices through a hollow pipe from what began as one voice on a single wire thus much has been achieved in the art of transmitting man's voice to that distant place but when there were many men at that distant place and only one was meant to hear this was the second major problem foreseen by Bell so many years ago the problem of connecting or switching a given call to one specific person out of many to connect one telephone with one other telephone only one line was required connecting three telephones required only three lines but to interconnect five would require 10 lines 721 lines and for 10 you would need 45 and interconnecting 100 telephones would require over 4900 lives so it became evident early in telephone history that central offices were needed for switching calls to make connections the telephone companies use the most valuable invention of all time an invention for which unfortunately Bell System research cannot take credit the girl operator had all the qualifications that were required to make connections in those days she had responsiveness she had memory Boston Parkway 3 - yes sir she had the mechanical dexterity to handle the switching process and she had logic to select another route if no line was available perhaps I can connect you through Hartford profit get me Boston Parkway 3 to memory logic and mechanical dexterity all were there in that original switching system but it's another of the wonders of research and development that they are all here too in a modern telephone office today's automatic switching system can remember each digit of a number as you dial it it provides the logic to figure out the route your call should take and it has the mechanical dexterity to send your call quickly on its way but despite all the advances in automatic equipment thousands of women are still required to ensure the personal attention so important to good telephone service however was today's direct distance dialing a customer in New York can dial his own call to San Francisco if one Road is busy the equipment automatically tries alternate routes until it completes the call at a speed close to magic and the cost of the call is just about two dollars instead of the twenty two dollars it cost back in 1915 this fabulously efficient equipment produced by Western Electric manufacturing arm of the bell system makes possible the automatic transmission and switching of 200 million telephone conversations in a single day to bring the far sound ever nearer ever clearer but the improvement of communications never stops at Bell Telephone laboratories thousands of technicians engineers and scientists work in these buildings in New Jersey that are the center of research and development activities for the Bell System the leaders at Bell Laboratories have always believed that research scientists should have freedom of ideas freedom of action a man is free to seek what rules he will working alone or with others who also seek new knowledge which will add to man's understanding of his world this concept of freedom guides men who have been seeking answers for a lifetime it guides men whose days of searching have just begun and advance in communications at Bell Laboratories is only the take-off point for basic research scientists who seek constantly for new knowledge for example these relay switches link the pathway for your calls across town and across the nation they can open or close a circuit in a thousandth of a second fast sure but not fast enough for this electronic age Engineers knew they could replace those relays with vacuum tubes a tube could operate as a switch in two millionths of a second however tubes require more power than relays and they generate more heat therefore they require more space and in many cases a tube has a limited lifespan rather than either a relay or a vacuum tube what they really needed was a device smaller than a relay that would operate as fast as a vacuum tube on far less power generate little or no heat and last practically forever and if like the vacuum tube this device could amplify as well as switch it would be out of this world but it was too much to expect that basic research would ever find such a device or was it on a day of 1946 in a search for new knowledge Bell Laboratories scientists stepped up a long continuing study with certain unusual solid materials called semiconductors these Arni's are good conductors of electricity like copper nor good insulators like glass they're somewhere in between a new frontier can be a mountain range or it can be a piece of material held in a man's hand like this semiconductor germanium much of the work with semiconductors was in theory with formula leading to formula there were endless experiments to test these theories in one a piece of germanium through which a current was flowing was placed in a magnetic field the magnetic field deflected the electrons to one side of the sample and fulfilled one of the predictions about the nature of semiconductors in this photo electric effect experiment a spinning disc interrupts a beam of light directed toward a piece of germanium which is dipped into a liquid conductor of electricity the results one measured proved that light causes a change in the charge on the surface of the semiconductor and there were tests involving a piece of germanium said a hair's breadth from a vibrating metal electrode the changes observed revealed how the electrical nature of the atoms near the surface of the semiconductor finally on a morning in December 1947 Theory stood at the threshold of proof the experimenters had wired into a circuit this small device without connecting the device into the circuit this was the sound but when it was connected the sound was much louder than before here was the first transistor it could amplify and switch born out of pure research it was to revolutionize the communications world for their discovery of the transistor Walter Brattain William Shockley and John Bardeen were awarded the Nobel Prize for Physics in 1956 in Stockholm where another Bell scientist Clinton Davisson had received a similar honor in 1937 this scientific breakthrough meant that far smaller assemblies using transistors and other new semiconductors could be built to replace conventional switching equipment an experimental electronic central office of the future is undergoing tests at Bell Laboratories occupying but a single room this electronic central office will one day make possible many unheard-of telephone services or home and business and it will serve as many telephones faster and better and a building full of equipment does today today when the transistor has been put to use in thousands of applications from hearing aids to satellite transmitters few remember it is only one of the many valuable byproducts that were born in communications research for example the first practical talking motion pictures were an outgrowth of earlier Bell System work in sound recording as far back as 1927 a television system was operating successfully between Washington DC and Bell Laboratories in New York in World War two German buzz bombs threatened England's very survival but radar gun directors developed with the help of Bell Telephone scientists and engineers enabled Gunners to destroy the deadly terror before it ever reached its target the distant early warning line and other communication systems across the Arctic wastes have grown out of telephone research and development as have the invaluable guidance systems for intercontinental missiles and guidance systems for interceptor missiles that can seek out and destroy approaching missiles but as important as telephone research has been to our national defense its primary name remains the constant improvement of communications here the heart of the bell solar battery permanent in plans for satellite communications goes into an oven for treatment two heads are apparently better than one for telephone research in the science of solved this experiment reveals how people are able to locate the direction of sound the equipment in this huge equalist chamber including microphones in the dummy's head from its acoustic scientists to influence the girls hearing of test songs this new knowledge is expected to bring improvements in transmission of both radio and TV stereophonic programs this tiny memory plate installed in a central office may mean that when you are going out for the evening you can simply dial in a number where you can be reached and have your calls forwarded automatically machines that talk to machines research and data transmission means that tomorrow's business will be able to transmit a hundred page report coast-to-coast in a matter of seconds this astonishing new device is known as the optical maser it operates on the power of an ordinary light bulb to project a thin rod like invisible beam of light that may eventually carry telephone calls and television programs scientists believe that in the future the optical maser will be able to carry many hundreds of thousands of telephone calls and television programs all at one time on a single beam of light the day when all of us can see as well as hear the party we are telephoning is still some years away but test models are already in daily use between two telephone laboratories 30 miles apart and who knows the housewife of tomorrow may do her shopping like this this is sunlight nickel an aluminized reflector balloon ten stories high when satellite hacker was launched by the National Aeronautics and Space Administration in August 1960 it made news that time the eyes of all the world a scientist spoke into the telephone in California and his voice signals were bounced off satellite echo in outer space and reflected back to earth to be heard by a telephone scientist in New Jersey this fantastically sensitive receiving equipment developed at Bell Laboratories amplified the faint signals from outer space ten million times and made possible that first conversation bounced off a man-made move telephone men next designed more sophisticated satellites powered by solar batteries and equipped with radio transmitters and receivers part of the preparations for orbiting the first satellite built and launched at private industries expense as ever more efficient satellites are sent to outer space the intellectual thrust for new knowledge by research scientists will bring the day ever closer when man has a better understanding of his world and its place in the universe to search the heavens with a giant ear and listen for the whisper of the stars to see within the molecule the atom and within the atom the unfathomable secrets of its parts to delve the boundless depths of one's own mind find some truth which through all time has defied the final to strive to ignite a single spark which will flame another candle against the dark that man may better know his worth this is the spirit of research the spirit which carries the scientists in communications ever forward a man in one part of the country may communicate with another in a distant place only yesterday that distant place was across a competent today across the sea now to all peoples of all lands and the day after who can say but one thing issue in the days that lie ahead from however far man may wish to communicate with math system scientists and engineers will continue to find new ways to bring the far sound you you

Channel: AT&T Tech Channel

Views: 66,996

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Keywords: Sound (Literature Subject), Music Education (Field Of Study), AT&T Archives, Bell Laboratories, Telephone, Long Distance, History, Communications, 1960s, Classic, Documentary, Technology (Industry), AT&T (Award Winner), Communication (Industry), Performing

Id: SS5X5BkIKpM

Length: 26min 51sec (1611 seconds)

Published: Tue Jan 06 2015