Marconi, Tesla and the Radio Wars (Presented by Bob Primak to the Lexington Technology Group Jan
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Thomas Edison Vs Nikola Tesla THOMAS EDISON VS NIKOLA TESLA
M C SCIENTIFIC RIVALRIES PHERSON AND SCANDALS In the early 1880s, only a few wealthy people had electric lighting in their homes. Everyone else had to use more dangerous lighting, such as gas lamps. Eager companies wanted to be the first to supply electricity to more Americans. The early providers would set the standards—and reap great profits. Inventor THOMAS EDISON already had a leading role in the industry: he had in- vented the fi rst reliable electrical lightbulb. By 1882 his Edison Electric Light Company was distributing electricity using a system called direct current, or DC. But an inventor named NIKOLA TESLA challenged Edison. Tesla believed that an alternating cur- CURRENTS THE OF rent—or AC—system would be better. With an AC system, one power station could deliver electricity across many miles, compared to only about one mile for DC. Each inventor had his backers. Business tycoon George Westinghouse put his money behind Tesla and built AC power stations. Meanwhile, Edison and his DC backers said that AC could easily electrocute people. Edison believed this risk would sway public opinion toward DC power. The battle over which system would become standard became known as the War of the Currents. This book tells the story of that war and the ways in which both kinds of electric power changed the world. READ ABOUT ALL OF THE OF THE SCIENTIFIC RIVALRIES AND SCANDALS BATTLE OF THE DINOSAUR BONES: Othniel Charles Marsh vs Edward Drinker Cope DECODING OUR DNA: Craig Venter vs the Human Genome Project CURRENTS THE RACE TO DISCOVER THE -
Army Radio Communication in the Great War Keith R Thrower, OBE
Army radio communication in the Great War Keith R Thrower, OBE Introduction Prior to the outbreak of WW1 in August 1914 many of the techniques to be used in later years for radio communications had already been invented, although most were still at an early stage of practical application. Radio transmitters at that time were predominantly using spark discharge from a high voltage induction coil, which created a series of damped oscillations in an associated tuned circuit at the rate of the spark discharge. The transmitted signal was noisy and rich in harmonics and spread widely over the radio spectrum. The ideal transmission was a continuous wave (CW) and there were three methods for producing this: 1. From an HF alternator, the practical design of which was made by the US General Electric engineer Ernst Alexanderson, initially based on a specification by Reginald Fessenden. These alternators were primarily intended for high-power, long-wave transmission and not suitable for use on the battlefield. 2. Arc generator, the practical form of which was invented by Valdemar Poulsen in 1902. Again the transmitters were high power and not suitable for battlefield use. 3. Valve oscillator, which was invented by the German engineer, Alexander Meissner, and patented in April 1913. Several important circuits using valves had been produced by 1914. These include: (a) the heterodyne, an oscillator circuit used to mix with an incoming continuous wave signal and beat it down to an audible note; (b) the detector, to extract the audio signal from the high frequency carrier; (c) the amplifier, both for the incoming high frequency signal and the detected audio or the beat signal from the heterodyne receiver; (d) regenerative feedback from the output of the detector or RF amplifier to its input, which had the effect of sharpening the tuning and increasing the amplification. -
Electret Microphone Replacement for a Carbon Insert
The VMARS Newsletter Issue 29 Electret microphone replacement for a carbon insert Colin Guy G4DDI When I found that I had a dud carbon insert in an H33F/PT handset, and I couldn’t find another insert that fitted (the original is about 1” diameter) I looked around for an alternative. Trevor Sanderson’s excellent article “The RAF Microphone” (Radio Bygones issue 79/80) makes reference to the use of electret inserts with an IC preamplifier in telephones and aircraft headsets, but the information given was too scant to make construction of one of these possible without reference to the IC data sheet, and the IC’s are expensive and difficult to obtain. I had a GPO type 21A insert, but the innards of this when dismantled were still too large to fit into the available space. The H33 handset is very slim, and also virtually solid, so there is very little room in which to place a preamplifier. A dig around on the internet turned up the following article written by F. Hueber, originally published in Elektor Electronics December 1994, and is published here with permission from Elektor Electronics magazine, December 1994, copyright Segment B.V., Beek (Lb.), The Netherlands, www.segment.nl. The original article included a pcb layout, but I built mine on a strip of veroboard four tracks wide by about 2” (see photo) and mounted it on the back of the ptt switch. The electret insert was acquired from a scrap telephone and all the rest of the components from TV panels. To save space the rectifier and R12 weren’t included, care being taken to ensure that the polarity was correct. -
The Stage Is Set
The Stage Is Set: Developments before 1900 Leading to Practical Wireless Communication Darrel T. Emerson National Radio Astronomy Observatory1, 949 N. Cherry Avenue, Tucson, AZ 85721 In 1909, Guglielmo Marconi and Carl Ferdinand Braun were awarded the Nobel Prize in Physics "in recognition of their contributions to the development of wireless telegraphy." In the Nobel Prize Presentation Speech by the President of the Royal Swedish Academy of Sciences [1], tribute was first paid to the earlier theorists and experimentalists. “It was Faraday with his unique penetrating power of mind, who first suspected a close connection between the phenomena of light and electricity, and it was Maxwell who transformed his bold concepts and thoughts into mathematical language, and finally, it was Hertz who through his classical experiments showed that the new ideas as to the nature of electricity and light had a real basis in fact.” These and many other scientists set the stage for the rapid development of wireless communication starting in the last decade of the 19th century. I. INTRODUCTION A key factor in the development of wireless communication, as opposed to pure research into the science of electromagnetic waves and phenomena, was simply the motivation to make it work. More than anyone else, Marconi was to provide that. However, for the possibility of wireless communication to be treated as a serious possibility in the first place and for it to be able to develop, there had to be an adequate theoretical and technological background. Electromagnetic theory, itself based on earlier experiment and theory, had to be sufficiently developed that 1. -
Thomas Edison Alexander Graham Bell
The Inventing Game Cut out the images. Cut out the name of the inventor separately. Read out the text as a clue. Can people match the correct name and image? THOMAS EDISON Clue The first great invention developed by (don’t say the name) Thomas Edison was the tin foil phonograph. A prolific producer, Edison is also known for his work with light bulbs, electricity, film and audio devices, and much more. ALEXANDER GRAHAM BELL Clue In 1876, at the age of 29, (don’t say the name) Alexander Graham Bell invented his telephone. Among one of his first innovations after the telephone was the "photophone," a device that enabled sound to be transmitted on a beam of light. GEORGE WASHINGTON CARVER Clue (Don’t say the name) George Washington Carver was an agricultural chemist who invented 300 uses for peanuts and hundreds of more uses for soybeans, pecans, and sweet potatoes. His contributions chang ed the history of agriculture in the south. ELI WHITNEY Clue (Don’t say the name) Eli Whitney invented the cotton gin in 1794. The cotton gin is a machine that separates seeds, hulls, and other unwanted materials from cotton after it has been picked. JOHANNES GUTTENBERG Clue (don’t say the name) Johannes Gutenberg was a German goldsmith and inventor best known for the Gutenberg press, an innovative printing machine that used movable type. JOHN LOGIE BAIRD Clue (don’t say the name) John Logie Baird is remembered as the inventor of mechanical television (an earlier version of television). Baird also patented inventions related to radar and fibre optics. -
Alexander Graham Bell 1847-1922
NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA BIOGRAPHICAL MEMOIRS VOLUME XXIII FIRST MEMOIR BIOGRAPHICAL MEMOIR OF ALEXANDER GRAHAM BELL 1847-1922 BY HAROLD S. OSBORNE PRESENTED TO THE ACADEMY AT THE ANNUAL MEETING, 1943 It was the intention that this Biographical Memoir would be written jointly by the present author and the late Dr. Bancroft Gherardi. The scope of the memoir and plan of work were laid out in cooperation with him, but Dr. Gherardi's untimely death prevented the proposed collaboration in writing the text. The author expresses his appreciation also of the help of members of the Bell family, particularly Dr. Gilbert Grosvenor, and of Mr. R. T. Barrett and Mr. A. M. Dowling of the American Telephone & Telegraph Company staff. The courtesy of these gentlemen has included, in addition to other help, making available to the author historic documents relating to the life of Alexander Graham Bell in the files of the National Geographic Society and in the Historical Museum of the American Telephone and Telegraph Company. ALEXANDER GRAHAM BELL 1847-1922 BY HAROLD S. OSBORNE Alexander Graham Bell—teacher, scientist, inventor, gentle- man—was one whose life was devoted to the benefit of mankind with unusual success. Known throughout the world as the inventor of the telephone, he made also other inventions and scientific discoveries of first importance, greatly advanced the methods and practices for teaching the deaf and came to be admired and loved throughout the world for his accuracy of thought and expression, his rigid code of honor, punctilious courtesy, and unfailing generosity in helping others. -
The Early Years of the Telephone
©2012 JSR The early years of the telephone The early years of the telephone John S. Reid Before Bell Ask who invented the telephone and most people who have an answer will reply Alexander Graham Bell, and probably clock it up as yet another invention by a Scotsman that was commercialised beyond our borders. Like many one line summaries, this is partly true but it credits to one person much more than he really deserves. Bell didn’t invent the word, he didn’t invent the concept, what ever the patent courts decreed, and actually didn’t invent most of the technology needed to turn the telephone into a business or household reality. He did, though, submit a crucial patent at just the right time in 1876, find backers to develop his concept, promoted his invention vigorously and pursued others through the courts to establish close to a monopoly business that made him and a good many others very well off. So, what is the fuller story of the early years of the telephone? In the 1820s, Charles Wheatstone who would later make a big name for himself as an inventor of telegraphy equipment invented a device he called a ‘telephone’ for transmitting music from one room to the next. It was not electrical but relied on conducting sound through a rod. In the same decade he also invented a device he called a ‘microphone’, for listening to faint sounds, but again it was not electrical. In succeeding decades quite a number of different devices by various inventors were given the name ‘telephone’. -
Tesla's Coil. a Toy Or Useful Thing in the Life of Radio Engineering?
УДК 537 Ільчук Д.Р. Tesla's coil. A toy or useful thing in the life of radio engineering? Вінницький національний технічний університет Аннотація. У цій статті, подан опис такого приладу як Котушка Тесли. Наведені її характеристики, принцип роботи, історія створення та значення в сучасному житті. Також описані процеси створення власноруч та розсуди про практичність даного виробу у реальному житті. Ключові слова: Котушка індуктивності, висока напруга, Нікола Тесла, радіотехніка, електрична дуга. Abstract. This article contains a description of the device as a Tesla coil. These characteristics of the principle of history and value creation in modern life. Also describes the process of creating his own judge and practicality of this product in real life. Keywords: Inductor, high voltage, Nikola Tesla, radio, electric arc. I.Introduction Perhaps in the life of every student comes a time when it begins to be interested in their field. In some it comes in the first year, someone on last. At the beginning of the 3rd year I finally decided to solder something with their hands. The choice immediately fell on Tesla coil. But is this thing so important, whether it is only a toy, which is impossible to do anything useful? Let us know about it. II. Summary The Tesla coil is an electrical resonant transformer circuit designed by inventor Nikola Tesla around 1891 as a power supply for his "System of Electric Lighting".It is used to produce high-voltage, low-current, high frequency alternating-current electricity. Tesla experimented with a number of different configurations consisting of two, or sometimes three, coupled resonant electric circuits. -
Method of Accommodating for Carbon/Electret Telephone Set Variability in Automatic Speaker Verification
Europaisches Patentamt 19 European Patent Office Office europeen des brevets © Publication number: 0 654 781 A2 12 EUROPEAN PATENT APPLICATION @ Application number: 94308231.3 @ Int. CI.6: G10L 5/06 (22) Date of filing : 09.11.94 (So) Priority: 19.11.93 US 155973 @ Inventor: Sachs, Richard M. 64 Sunset Place @ Date of publication of application : Middletown, New Jersey 07748 (US) 24.05.95 Bulletin 95/21 Inventor : Schoeffler, Max S. 17 Kenwood Lane @ Designated Contracting States : Matawan, New Jersey 07747 (US) DE ES FR GB IT (74) Representative : Watts, Christopher Malcolm @ Applicant : AT & T Corp. Kelway, Dr. et al 32 Avenue of the Americas AT&T (UK) Ltd. New York, NY 10013-2412 (US) 5, Mornington Road Woodford Green Essex, IG8 0TU (GB) (S) Method of accommodating for carbon/electret telephone set variability in automatic speaker verification. In verification method of (57) a speaker system, a FIG. 6 compensating for differences in speech sam- ples obtained during registration and those obtained during verification due to the use of VERIFICATION (4-WAY) different types of microphones is provided by ,601 at least of the such that filtering one samples PROMPT the similarities of the two samples are in- creased. The filtered sample is used within the ,604 speaker verification matching process. A two- RECEIVE VERIFICATION way comparison is disclosed in which both a SPEECH SAMPLE verification speech sample and a reference sample are filtered with nonlinear microphone r609 ,606 characteristics such as carbon microphone PRODUCE CARBON characteristics. A is also VERIFICATION FILTER four-way comparison PATTERN SAMPLE disclosed in which patterns produced from un- filtered verification and reference samples and 611 from the filtered verification PRODUCE CARBON patterns produced FILTERED and reference samples are compared to identify VERIFICATION a match. -
NIKOLA TESLA July 10, 1856 – January 7, 1943
The AMA History Project Presents: Biography of NIKOLA TESLA July 10, 1856 – January 7, 1943 Written by GS (03/1976); Transcribed and reformatted by JS (09/2010) The following was published in the March 1976 issue of Model Aviation magazine, written by George V. Sosic. TESLA – The Father of RC On September 2, 1897, the Chief U.S. Examiner of Patents visited the laboratory of Nikola Tesla in New York. This visit was prompted by his belief that this inventor’s latest patent application went far beyond the realm of possibility in his claim of a practical wireless control system for vessels and vehicles from a great distance. It should be noted that the above date preceded the Wright brothers’ airplane by more than six years. Tesla gave his control system the name of Teleautomatics. It is now known as the guided-missile principle, RPV (remotely piloted vehicles) and radio control, which the model aircraft fraternity calls RC. This article was written for model aircraft builders and fliers, so the writer will refer to it as RC. Four years before Tesla shook up the Chief U.S. Examiner of Patents with his application for a patent on RC, he demonstrated a vacuum-tube radio for voice and music at the 1893 World’s Fair in Chicago, so anyone with any electronic knowledge at all can easily see that his next logical step would be to convert his frequency control and tuning knowledge to other uses such as RC and automation. Tesla showed his bench-mounted RC components in working order. -
Tesla's Connection to Columbia University by Dr. Kenneth L. Corum
* Tesla’s Connection to Columbia University by Kenneth L. Corum and James F. Corum, Ph.D. “The invention of the wheel was perhaps rather obvious; but the invention of an invisible wheel, made of nothing but a magnetic field, was far from obvious, and that is what we owe to Nikola Tesla.” Professor Reginald Kapp, 1956 INTRODUCTION The Electrical Engineering curriculum at Columbia University, though not the first in the US, is one of the oldest and most respected EE programs in the world. From the beginning, a conscientious effort was made to base it on a foundation of science. It has been guided by the specific philosophy stated by Professor Michael Pupin: “Professor Crocker and I maintained that there is an ‘electrical science’ which is the real soul of electrical engineering.” Arguably the most stunning and significant lecture in modern history was presented one spring evening, more than a century ago, at Columbia University. The wealth of nations turned on its merits. Weighing on the balances would be our vast cities, civilization, and quality of life. But, what was it? . .Whatever it was, its impact has been as momentous for the progress and prosperity of civilization as the invention of the wheel! . It was Tesla’s great discovery and analysis of the rotating magnetic field, and a means for the electrical distribution of energy.1 As a result of the analysis presented in this lecture, the great Falls of Niagara would soon be harnessed for the benefit of mankind and launch civilization into the “Electromagnetic Century”. The Engineering Council for Professional Development (now called ABET) has defined “Engineering” as “that profession which utilizes the resources of the planet for the benefit of mankind”. -
C.C.I.F.: Proceedings of the Xth Plenary Meeting (Budapest, 1934)
A NOTE FROM THE ITU LIBRARY & ARCHIVES SERVICE An erratum for this volume was issued for the French version of this publication. For reference purposes, it has been included with this PDF. This electronic version (PDF) was scanned by the International Telecommunication Union (ITU) Library & Archives Service from an original paper document in the ITU Library & Archives collections. La présente version électronique (PDF) a été numérisée par le Service de la bibliothèque et des archives de l'Union internationale des télécommunications (UIT) à partir d'un document papier original des collections de ce service. Esta versión electrónica (PDF) ha sido escaneada por el Servicio de Biblioteca y Archivos de la Unión Internacional de Telecomunicaciones (UIT) a partir de un documento impreso original de las colecciones del Servicio de Biblioteca y Archivos de la UIT. ﻫﺬﻩ ﺍﻟﻨﺴﺨﺔ ﺍﻹﻟﻜﺘﺮﻭﻧﻴﺔ (PDF) ﻧﺘﺎﺝ ﺗﺼﻮﻳﺮ ﺑﺎﻟﻤﺴﺢ ﺍﻟﻀﻮﺋﻲ ﺃﺟﺮﺍﻩ ﻗﺴﻢ ﺍﻟﻤﻜﺘﺒﺔ ﻭﺍﻟﻤﺤﻔﻮﻇﺎﺕ ﻓﻲ ﺍﻻﺗﺤﺎﺩ ﺍﻟﺪﻭﻟﻲ ﻟﻼﺗﺼﺎﻻﺕ (ITU) ﻧﻘﻼ ﻣﻦ ﻭﺛﻴﻘﺔ ﻭﺭﻗﻴﺔ ﺃﺻﻠﻴﺔ ﺿﻤﻦ ﺍﻟﻮﺛﺎﺋﻖ ﺍﻟﻤﺘﻮﻓﺮﺓ ﻓﻲ ﻗﺴﻢ ﺍﻟﻤﻜﺘﺒﺔ ﻭﺍﻟﻤﺤﻔﻮﻇﺎﺕ. ً 此电子版(PDF版本)由国际电信联盟(ITU)图书馆和档案室利用存于该处的纸质文件扫描提供。 Настоящий электронный вариант (PDF) был подготовлен в библиотечно-архивной службе Международного союза электросвязи путем сканирования исходного документа в бумажной форме из библиотечно-архивной службы МСЭ. © International Telecommunication Union COMITE CONSULTATIF INTERNATIONAL TELEPHONIQUE (C.C.I.F.) PROCEEDINGS OF THE Xth PLENARY MEETING Budapest, yrd— 10th September, 1934 TRANSLATED INTO ENGLISH BY THE TECHNICAL STAFF OF THE INTERNATIONAL STANDARD ELECTRIC CORPORATION Volume I ... General; Questions for Study ; Bibliography pages 5-107 Volume II ... Protection.............................................................. pages 111-156 Volume III ... ... Transmission; Definitions; Recommendations; Specifications ...................................... pages 159-334 Volume IV ... ... Transmission; Maintenance ........................... pages 338-536 Volume V ..