Alternating Currents and Ether: Two Paradigms of Radio
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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. -
BY F7-6-4 AITORNEY Patented Jan
Jan. 15, 1935. G, VON ARCO 1,988,097 "FREQUENCY MULTIPLICATION Filed Dec. 10, 1929 w R S. a s n INVENTOR GEORG Wo ARCO BY f7-6-4 AITORNEY Patented Jan. 15, 1935 1988,097 UNITED STATES PATENT OFFICE 1988,097 FREQUENCY MULTIPLICATION Georg von Arco, Berlin, Germany, assignor to Telefunken Geselschaft fir Drahtlose Tele graphie m. b. H., Berlin, Germany Application December 10, 1929, Serial No. 412,962 Renewed April 9, 1932 2 Claims. (C. 250-36) In my copending United States patent appli multiplier for use with my present invention cation Serial Number 70,729, fled November 23, although it is to be clearly understood that this 1925, now United States Patent 1,744,711, pat frequency multiplier or harmonic producer may ented January 21, 1930, I have disclosed an s efficient arrangement for frequency multiplying have wide application in the radio frequency or energy consisting of a master oscillator, means cognate arts rather than be limited to use in for splitting the phase of currents generated the System herein described. More specifically by the master oscillator and means for utilizing in connection with my harmonic oscillation gen the split phase currents to produce energy of erator, an object of my present invention is to O provide an electron discharge device having a multiplied frequency relative to the master OS parallel tuned circuit tuned to a harmonic fre 10 cillator frequency, by impulse excitation. In quency connected between its anode and cath that application, I referred to the efficient use of ode, and a Source of fundamental frequency en the System in directive transmitting arrange ergy connected or coupled to the control elec 5 ments, and this case which is a continuation in trode and cathode of the tube, the control elec part thereof, describes in detail how the ar trode or grid being so biased negatively that 5 rangement may be carried out. -
The Discovery >
MARCONI and z the Discovery > of WIRELESS * by ~ LESLIE READE - I § Faber $ Histone v/d Radic } . J MEN AND EVENTS General Editor: A. F. Alington Marconi and the Discovery of Wireless by LESLIE READE This is a lively and well-informed biography by an author for whom the invention of wireless has never lost its magic. Marconi’s scientific achievements are described simply and clearly, and the book includes an interesting account of the work of the early wireless operators or ‘Marconi men.’ 9s 6d net MEN AND EVENTS Editor: A. F. Alington * SIR WINSTON CHURCHILL by Alan Farrell THE MAN WHO DISCOVERED PENICILLIN The Life of Sir Alexander Fleming by W. A. C. Bullock THE MAN WHO FREED THE SLAVES The Story of William Wilberforce by A. and H. Lawson THE BATTLE OF BRITAIN by N. D. Smith THE ENGLISH CIVIL WAR by Sutherland Ross THE LAMPS GO OUT 1914 and the Outbreak of War by A. F. Alington MARCONI AND THE DISCOVERY OF WIRELESS by Leslie Reade THE RUSSIAN REVOLUTIONS by David Footman Other titles in preparation Marconi and the Discovery of Wireless LESLIE READE FABER AND FABER 24 Russell Square London First published in mcmlxiii by Faber and Faber Limited 24 Russell Square London W.C.i Printed in Great Britain by Latimer Trend & Co Ltd Plymouth A.U rights reserved © Leslie Reade 1963 TO MY FATHER Contents Foreword page 11 Prologue 13 I. ‘The Air is Full ... of Miracles’ 15 II. From Italian Chestnuts to Signal Hill 27 III. Foes, Friends and a Prize 48 IV. -
Transocean and German Wireless Telegraphy, 1914-1922
"The Path to Freedom"? Transocean and German Wireless Telegraphy, 1914-1922 The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Evans, Heidi Jacqueline. 2010. "The path to freedom"? Transocean and German wireless telegraphy, 1914-1922. Historical Social Research 35(1): 209-233. Published Version http://nbn-resolving.de/urn:nbn:de:0168-ssoar-285403 Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:11375397 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA “The Path to Freedom”? Transocean and German Wireless Telegraphy, 1914-1922 Heidi J. S. Evans ∗ Abstract: »„Der Weg ins Freie”? Transocean und die deutsche drahtlose Te- legraphie, 1914-1922«. This article examines the early years of Transocean, a news agency owned and run by the German government, and its use of wire- less telegraphy from 1914 to 1922. This investigation of the infancy of wireless technology demonstrates that technology plays a constitutive role in defining news. The German government used the new possibilities innate in the medium of wireless to carve out their own sphere of operation in the seas and on conti- nents where German telegraph news had never played a major role, in particu- lar East Asia. Wireless telegraphy enabled the German government to circum- vent the British communications blockade in World War I. Afterwards, Transocean’s wireless transmissions to East Asia and ships en route caused an uproar in Britain disproportionate to its circulation. -
Inventing Television: Transnational Networks of Co-Operation and Rivalry, 1870-1936
Inventing Television: Transnational Networks of Co-operation and Rivalry, 1870-1936 A thesis submitted to the University of Manchester for the degree of Doctor of Philosophy In the faculty of Life Sciences 2011 Paul Marshall Table of contents List of figures .............................................................................................................. 7 Chapter 2 .............................................................................................................. 7 Chapter 3 .............................................................................................................. 7 Chapter 4 .............................................................................................................. 8 Chapter 5 .............................................................................................................. 8 Chapter 6 .............................................................................................................. 9 List of tables ................................................................................................................ 9 Chapter 1 .............................................................................................................. 9 Chapter 2 .............................................................................................................. 9 Chapter 6 .............................................................................................................. 9 Abstract .................................................................................................................... -
Television, Farnsworth and Sarnoff
by AARON SORKIN directed by NICK BOWLING STUDY GUIDE prepared by Maren Robinson, Dramaturg This Study Guide for The Farnsworth Invention was prepared by Maren Robinson and edited by Lara Goetsch for TimeLine Theatre, its patrons and educational outreach. Please request permission to use these materials for any subsequent production. © TimeLine Theatre 2010 — — STUDY GUIDE — Table of Contents The Playwright: Aaron Sorkin .................................................................................... 3 The History: Sorkin’s Artistic License ........................................................................ 3 The People: Philo T. Farnsworth ................................................................................. 4 The People: David Sarnoff ........................................................................................... 6 The People: Other Players ........................................................................................... 8 Television: The Business ........................................................................................... 14 The Radio Corporation of America Patent Pool ................................................ 14 Other Players in Early Radio and Television ................................................... 16 Television: The Science .............................................................................................. 16 Timeline of Selected Events: Television, Farnsworth and Sarnoff .......................... 20 Television by the Numbers ....................................................................................... -
A Short History of Radio
Winter 2003-2004 AA ShortShort HistoryHistory ofof RadioRadio With an Inside Focus on Mobile Radio PIONEERS OF RADIO If success has many fathers, then radio • Edwin Armstrong—this WWI Army officer, Columbia is one of the world’s greatest University engineering professor, and creator of FM radio successes. Perhaps one simple way to sort out this invented the regenerative circuit, the first amplifying re- multiple parentage is to place those who have been ceiver and reliable continuous-wave transmitter; and the given credit for “fathering” superheterodyne circuit, a means of receiving, converting radio into groups. and amplifying weak, high-frequency electromagnetic waves. His inventions are considered by many to provide the foundation for cellular The Scientists: phones. • Henirich Hertz—this Clockwise from German physicist, who died of blood poisoning at bottom-Ernst age 37, was the first to Alexanderson prove that you could (1878-1975), transmit and receive Reginald Fessin- electric waves wirelessly. den (1866-1932), Although Hertz originally Heinrich Hertz thought his work had no (1857-1894), practical use, today it is Edwin Armstrong recognized as the fundamental (1890-1954), Lee building block of radio and every DeForest (1873- frequency measurement is named 1961), and Nikola after him (the Hertz). Tesla (1856-1943). • Nikola Tesla—was a Serbian- Center color American inventor who discovered photo is Gug- the basis for most alternating-current lielmo Marconi machinery. In 1884, a year after (1874-1937). coming to the United States he sold The Businessmen: the patent rights for his system of alternating- current dynamos, transformers, and motors to George • Guglielmo Marconi—this Italian crea- Westinghouse. -
IEEE Sweden MN2020-Q2
IEEE SE MN2020-Q2 avenue of increasing our gains of membership to membership in all members of IEEE Sweden Individual Highlights: Editorial chapters. IEEE tools Section. The board online are readily made remains grateful to The challenges available to us to remain committed members. We created by coronavirus R8SYP UPDATE 2 efficient, creative, shall not relent in pandemic have been industrious and informed. supporting and motivating enormous. Nonetheless, IEEE The pandemic’s you to reach the pinnacle IEEE’s response to Sweden section is COVID19 3 unprecedented of your set aside goals. determined to continue to circumstances afforded This Newsletter is subject make impact for the 2020 many of us opportunities to nonstop improvements Chapters Summary fiscal year. It is a trying time in eHealth. My recent and aims at sharing Activities 3 for the usual physical published paper titled information with IEEE Young Professionals 3 appearances in conferences “COVID-19 Patient Health members. Hence, we and meetings, but created Prediction Using Boosted kindly ask for increase awareness of Membership statistics in Random Forest contributions, feedback Sweden 4 virtual meetings which we Algorithm” is available and involvement from our are determined to explore online that supports IEEE readers. Please submit to and utilize in full. I Action for Industry 4 stand point on Covid-19. the Newsletter Editor, Dr. personally continue to see We shall continue to Celestine Iwendi this challenge as a strong deliver as entrusted the [email protected] Alexanderson Day 5 A message from the Sweden Section Chair Sites for Success 7 Dear IEEE Member, planned events and technology that enables us conferences such as the to connect and deliver in ISCMI20; that was to be held the current situation. -
Television As History: Representations of German Television
Linda Schulte-Sasse 32. Rejlections of Fascism (New York: Harper, 1982). See Rentschler, 59. 33. I am referringto some of the earliest studies on Nazi cinema: David Stewart Hull's Film in the Third Reich (Berkeley: U of Califomia P, 1969) and Erwin Leiser's Nazi Cinema, trans. G. Mander and D. Wilson, (New York: 6 Macmillan, 1974). 34. National,sozialistische Filmpolitik:Eine soziologische Untersuchung über die Spielfilme des dritten Reiches (Stuttgart: Enke, 1969). 35. "Propaganda," Screen 18.3 (Autumn 1977): 31. Television as History: 36. "Propaganda" 31. 37. For some interesting analyses of modern political spectacles in the form of Representations of German "Gesamtkunstwerk," see Eric Rentschler, "The Use and Abuse of Memory: Television Broadcasting, New German Film and the Discourse of Bitburg," New German Critique 36 (Fall 1985): 67-90 or Jochen Schulte-Sasse, "Electronic Media and Cultural 1935--1944 Politics in the Reagan Era: The Attack on Libya and Rands Across America as Postmodern Events," Cultural Critique 8 (Winter 1987/88): 123--52. 38. "Der Messingkauf' 563. William Uricchio Walter Benjamin's "Das Kunstwerk im Zeitalter seiner tech nischen Reproduzierbarkeit" ("The Work of Art in the Age ofMechanical Reproduction") appeared in the Zeitschrif für Sozialorchung several months after the Reich Broadcasting Company announced "the world' s 1 firstregular television service." The near simultaneity of the appearance of a new mass medium and an implicit critique of its cultural inscription marks a striking conjunction. Given the massive cultural role television subsequently assumed, and Benjamin' s relative marginalization to a small circle of intellectuals, it seems astonishing that his essay achieved a much higher profile in cultural memory than did the considerable develop ments of German television broadcasting between 1935 and 1944. -
ABSTRACT AWA Review Wireless Comes of Age on the West Coast1
Lee AWA Review Wireless Comes of Age on the West Coast1 !2011 Bartholomew Lee ABSTRACT This is a story primarily about young men and what they accomplished in a remarkable Radio as we know it time, the fi rst two decades of the 20th Century, had many fathers. Cali- and in remarkable places – especially in Cali- fornia enjoyed unique fornia in the Western United States. Guglielmo circumstances that gave (William) Marconi, in his early twenties, elec- rise to independent de- trifi ed the technical world of the late 19th Cen- velopment. Young men tury with his successes using Hertzian electro- explored and advanced magnetic waves to communicate at distance, devices and means of what we now call “radio.” He did this without communication as soon the wired connections to which the world had as they read about ear- turned with enthusiasm earlier in the century. lier advances, especially The telegraph, including undersea cables, and Marconi’s use of wireless the telephone, needed wire, and lots of it. Com- spark systems. The arc munication without such wires, at fi rst wireless as a generator of high telegraphy, opened new vistas. This was par- power continuous wave ticularly so looking out to the world’s oceans. energy for communica- Communication with ships at sea (Marconi’s tions came to California primary initial interest) was now possible. Then, and then the world. Doc a challenge to the expensive cable monopolies Herrold began the fi rst could be mounted. This was so because the new regular broadcasting to a “wireless” meant exactly that: no expensive, known audience around capital-intensive investments in cables, only 1912 in California, using in terminal stations. -
Sitzungsräume Persönlichk
VDE-Sitzungsräume mit großen Namen Heinrich Hertz Gustav Kirchhoff Georg Christoph Georg Simon Ohm Johann Phillipp Reis Lichtenberg Wilhelm Conrad Werner von Siemens Adolf Slaby Wilhelm Weber Konrad Zuse Röntgen Daten und Fakten von Persönlichkeiten aus der Geschichte der Elektrotechnik Heinrich Hertz 1857 – 1894 … bestimmte Ausbreitungsgeschwindigkeit und Frequenz von elektromagnetischen Wellen und entdeckte ihre Reflexion. Heinrich Hertz, ein Schüler von Hermann von Helmholtz, bestätigte die Annahme von James Clerk Maxwell, dass die Ausbreitung von elektromagnetischen Wellen denselben Charakter wie Lichtwellen haben müssten. Seine Erkenntnisse führten später zur Entwicklung des Radars und der Funktechnik. Die Einheit der Frequenz, eine Schwingung pro Sekunde = 1 Hertz (Hz), ist nach ihm benannt und seit 1933 im internationalen metrischen System verankert. Hertz wurde nach seinem Studium in Berlin bereits 1883 Privatdozent für theoretische Physik in Kiel. Von 1885 bis 1889 lehrte er in Karlsruhe und danach in Bonn. Auch der äußere Photoeffekt wurde 1886 von ihm entdeckt. Sein Assistent Wilhelm Hallwachs führte 1887 die Untersuchung weiter (Hallwachseffekt). Dieser Effekt spielte eine besondere Rolle bei der Formulierung der Lichtquantenhypothese durch Albert Einstein 1905. Gustav Kirchhoff 1824 – 1887 … entwickelte die nach ihm benannten Gesetze zur Berechnung elektrischer Stromkreise. Diese Formeln sind fundamental für Aufbau und Analyse elektrischer Schaltungen und somit für die Elektrotechnik. Kirchhoff promovierte in Königsberg zum -
1. MDI Combroad Fm 3Pp.Indd
COMMUNICATIONS AND BROADCASTING Milestones in Discovery and Invention COMMUNICATIONS AND BROADCASTING REVISED EDITION FROM WIRED WORDS TO WIRELESS WEB uHarry Henderson COMMUNICATIONS AND BROADCASTING: From Wired Words to Wireless Web, Revised Edition Copyright © 2007, 1997 by Harry Henderson All rights reserved. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, record- ing, or by any information storage or retrieval systems, without permission in writing from the publisher. For information contact: Chelsea House An imprint of Infobase Publishing 132 West 31st Street New York NY 10001 Library of Congress Cataloging-in-Publication Data Henderson, Harry. Communications and broadcasting : from wired words to wireless Web / Harry Henderson.—Rev. ed. p. cm. Includes bibliographical references and index. ISBN 0-8160-5748-6 1. Telecommunication—History—Juvenile literature. I. Title. TK5102.4.H46 2006 384—dc22 2006005577 Chelsea House books are available at special discounts when purchased in bulk quantities for businesses, associations, institutions, or sales promotions. Please call our Special Sales Department in New York at (212) 967-8800 or (800) 322-8755. You can find Chelsea House on the World Wide Web at http://www.chelseahouse.com Text design by James Scotto-Lavino Cover design by Dorothy M. Preston Illustrations by Sholto Ainslie and Melissa Ericksen Printed in the United States of America MP FOF 10 9 8 7 6 5 4 3 2 1 This book is printed on acid-free paper.