The doctor has just finished giving the young man a thorough physical examination.
"The best thing for you to do," the M.D. said, "is give up drinking and smoking, get to bed early and stay away from women."
"Doc, I don't deserve the best," said the patient. "What's second best?"
Vacuum tubeIn 1906, Dr. Lee DeForest (26 Aug 1873 - 30 Jun 1961), one of the “fathers of radio,'' announced his three-element electrical vacuum tube (now known as a triode) to a meeting of the American Institute of Electrical Engineers He had discovered that when a mesh, or grid, of wire was placed between the filament and collector “plate” in a diode tube (first made by J. Ambrose Fleming, 1904), a large voltage-amplifying effect could be produced. DeForest patented this vacuum tube on 15 Jan 1907. The ability of this tube to amplifiy weak signals was an invention as great as radio itself, because it made long-distance communication possible.[Image: early DeForest Audion] |
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