Telephone Technology in the Digital Age - A Tutorial for broadcasters

Telephone Technology in the Digital Age- A Tutorial for broadcastersBy Rolf Taylor06 February, 2000On the Seventh of March, 1876 Alexander Graham Bell received a patent forthe telephone. His patent was described as “Improvement in Telegraphy ...”The Bell Telephone Company was formed in July of 1877. While many at thetime scoffed at this invention, and Bell had a hard time getting investmentcapital (the powerful Western Union refused his offer to sell his patent for$100,000 in late 1876/early 1877), the public loved the telephone andacceptance grew rapidly. By December 1877 Western Union had formed theAmerican Speaking Telephone subsidiary to compete with Bell.Bell’s original apparatus was similar to a modern dynamic microphone. Apermanent magnet and a piece of moving metal interacted to induce current ina coil (the magneto effect). The original system used the same transducer forboth sending and receiving. At the far end the electrical energy was convertedback to vibrations thereby creating acoustic waves (i.e. sound). As early as1878 telephones had become available in places as far west as San Franciscowith the first exchange installed there in the January of that year.Transducer developmentOnce it became clear that the telephone was, to use a modern term, a “killerapp,” a number of other parties came up with alternative methods of telephonyin order circumvent Bell’s patents. A lot of energy and inventiveness (not tomention money) were invested in ...