DOCSLIB.ORG

25 Cents February 1923

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
25 Cents February 1923 CIRCULATION OF THIS ISSUE OVER 225,000 COPIES ,psyymems_ DIO 25 Cents February 1923 NEWS Over 175 I Ilustrations Edited by H.GERNSBACK `A LOOSE COUPLE THE 100% WIRELESS MAGAZINE CIRCULATION LARGER THAN ANY OTHER PUBLICATION www.americanradiohistory.com CUNNINGHAM TYPE C 300 PATENTED AMPLIFIES AS IT DETECTS Patent Notice Cunningham tubes are covered by pat- enta dated 11 -7 -05. 1- 15 -07, 2 -18 -08 and others issued and pending. Licensed only for amateur or experimental uses in radio communication. Any other use will be an infringement. TYPE C -300 Super - Sensitive DETECTOR $ 500 TYPE C -301 Give Clearest Reception Distortioaless AMPLIFIER Cunningham Tubes used in any standard receiving set tvill enable you and your friends to listen to news reports at breakfast, stock market quotations at lunch, $650 and in the evening sit in your comfortable living -room by the fireside and enjoy the finest music and entertainment of the day. Send 5c for new 32 -page Cunningham Tube catalog, containing detailed instruc- tion for the operation of Cunningham Tubes as well as numerous circuit diagrams and graphic illustrations of tube action. The Cunningham Technical Bureau is at your Service. Address your problems to Dept. R. The trade mark GE Eastern is the guarantee of these quality Home Office:- Representatives: - tubes. Each tube is built to most rigid specifica- 248 First Street 154 West Lake Street tions. San Francisco, Calif. Chicago, Illinois www.americanradiohistory.com Radio News for February, 1923 $ 00 2000Ohm 75o 30000hm Their Deep, Natural- Voiced Pitch Is Rapidly Selling Thousands ACTUALLY-thousands are being snapped up on the strength of their pleasing voice tone and keen sensitive- ness. The same hair -line refinement of design which for over eleven years has been so sharply pronounced in hundreds of Basco electrical units, here again shows itself in these skillfully constructed t11111In/f1111U' 111 iVJ T 1T! '.paII1111 Head Phones!) lunnuuuu1. .n "f Hear'More and Cost Less They are built right, pitched right and priced right. Close examination is convincing proof. They embody every high priced quality- perfect bal- ance, clear, scratchless reproduction. Coils encased in aluminum shell - light weight, easy on the head. Employ solid horse shoe magnet -no lami- nations. Bus-bar connections, no loose hair -like wires. Light, extra sensitive diaphragm, set to thousandths -of -an -inch accuracy N from magnet poles. Clean cut, rugged design throughout. Compare them with any other head set- irrespective of price-then you'll be convinced they're what you want. Ask your dealer to show you Basco Head Phones. If he hasn't them, write us direct. We also make the Basco Radio Frequency Transformer, Vernier and plain Rheo- stat, Variable Air Condensers, Tube Socket, Dials and a Complete Crystal Outfit. ! Write for our exceptional discount Put up in attractive orange Jobbers and Dealers and black cartons proposition, and name of our nearest factory representative. B.....rws V.BIIIIIIIIIII trattonI1111111111111111111111111lllllllllllllllllllllllllllllllllldt_tllllllllllll) (ó Milwaukee Wisconsin www.americanradiohistory.com IMP t' Constructive Criticism on Phone Design By John Dcpew The First High Power Broadcasting Station in Havana, Cuba By Ulpiano Muniz Broadcasting Mr. and Mrs. Brownlee Hold Hands First Presidential Message to By Ellis Parker Butler 1468 Congress By S. R. Winters Who's Who in Radio W. C. White 1469 Giving the Whole Town a Radin Concert By Armstrong Perry A Method of Eliminating the Carrier Wave in Radio Telephony By R. Heather 1469 Get Into the Code Work.. By Roy A. Anderson With the Amateurs 1470 Linking the World's Farms by Radio By J. Farrell 5HB Makes Radio History By F.. T. Jones 1472 Keeping the Public Sold on Radio New DX Records set by 67 1- at Honolulu, By Armstrong Perry Hawaii 1473 Secrecy in Radio Communication flow Amateurs Can Serve 1473 By J. O. Carr A Universal Receiver By Louis J. Gallo 1474 On the Transmission of Waves By Sir Oliver Lodge Form Wound Coils By S. E. Watson 1475 Electron, Electric \aves and Wireless Tele Design ni a Portable Short Wave Radio Wave - phony By Dr. J. A. Fleming, F. R. S. meter 1476 Results of $500 Prize Contest "Who Will Save ;\ Five Watt Telephone and Modulated C.W. the Radio Amateur" By H. Gernsback Transmitter By Jesse Marsten 1477 Our Popularizing Radio Scheme Correspondence from Readers 1479 Super -Regenerative Amplification Awards of the 550 Wrinkle Contest 1480 By William M. Smith Practical Hints for Amateur Constructors 1481 The Reflex Circuit By J. L. Goldsman Radio Digest 1482 Alkali Vapor Detector Tubes By Hugh A. Brown and Charles T. Knipp New Radio latents 1483 Radio Frequency Measurements Radio News Laboratories 1434 By L. R. Felder Radio Humor 1486 Radio Control By Major Raymond Philips Club Gossip 1487 The Ayes Have It By Jack Bront New Radio Legislation is Needea Damping: Its Meaning, Causes and Effects in By Carl Butman 1487 Radio By Louis Frank With the Sea -Going Op's Radio Frequency Amplification "1- Want By John M. Avery -To- Know" There are paid for on publication. .1 special rate Is paid for novel experiment : R A D I O N E W S is published on the nth of each month. highly desirable. are 12 numbers per year. Subscription price Is 83.30 s year in U. S. good photographs accompanying them are and I.osessbais. Canada and foreign countries. 51.O9 a year. l ' . S. coin R A D I O N E W S Monthly Entered as cerond -Nees matter at the as sell as 1'. S. Stamps accepted (nu foreign coins or stamps). Single Post Office at Jamaica, N. Y.. under the act of ]larch a, 1897. Title copies. 25 cents each. A sample ropy will be sent gratis on request. registered U. S. Patent Office. Copyright. 1921, by E. P. Co., Inc.. New Cheeks and money orders should. be drawn to order of EXPERIMENTER York. The Experimenter Publishing en.. 5:1 Park Place, N. Y. The PUBLISHING CO.. INC. If you should change your address notify us Contents of this magazine are copyrighted and muet not be reproduced Promptly. In order that copies be not miscarried or lost. No copies sent without giving full credit to the publication. after expiration. All communications and contributions to this Journal should he addressed R A D I O N E W S Is for esle at all newsstands In the United to Editor, RADIO NEWS, 812 Jamaica Avenue. Jamaica. New York: or States and Canada: also at The International News t'o., Ltd., Itream's 51 Park Place. New York, N. Y. l'naeceited contributions cannot he re Building. London E. C. 4, England. and at Itrentantis 37 Avenue de turned unless full postage has been included. All accepted contributions POpera, l'ari.. General Advertising Dept.. 53 Park Place, New York City. Western Advertising Representatives, Finucan & McClure. 720 Cass Street, Chicago, Ill. Kansas City Representative, Geo. F. Dillon, Republic Bldg.. Kansas City, Mo. Pacific Coast Advertising Representatives. A. J. Norris Hill Co.. Hearst Bldg.. San Francisco, Cal. Published by EXPERIMENTER PUBLISHING CO., INC., Publishers of "Radio News," "Science and Invention" and "Practical Electric,." Publication Office: Jamaica, N. Y. Editorial and General Offices: 53 Park Place, New York City H. GERNSBACK, President S. GERNSBACK, Treasurer R. W. DEMOTT, Secretary www.americanradiohistory.com Radio Nat's for February, 1923 1435 ss . fig tutsp -?na looks into and knows I-hetre is tir, lirniF fa dimerssi on ." s tY 1 a (iul Ri u wise Radials+ árages the gieafe5F disfr n c e s itll - . (,1 . .- ceí LONG RECORD of unequalled performance has won for the Grebe Receiver the unqualified en- dorsement of all good dealers. " Musings of Doctor Mu" - the stoz'y of the development of the Per- fect Receiver, free upon request. A. H. GREBE & CO. INCORPORATED RICHMOND HILL, N. Y. \ax°uniuuprnnhfr. Licensed under ..,. Armstrong U. S. %y Pat. No. 1113149 °oil i 4 -7,4-. 1 I o 4 : ° 44* ' www.americanradiohistory.com Radio Neste for February, 1923 Ghe proóress of Ohiropractic . s ,-,,/ Earamerar T 1S a far cry from Franklin's All of which simply proves that a kite to the electric lighting, gangplow in the hands of an ignor- transportation and communi- ant peasant is far more efficient than cating systems of today, or from a garden spade in the hands of the Watt's teakettle to the steam engines brightest, most learned and cultured and ocean steamers of the present ; gentleman in the world. yet it is no farther in either of these A brief survey of the discovery cases than it is from the experimen- and growth of this science may prove tal "push in the back" given to Har- illuminating. vey Lilliard, the deaf negro, by D. D. D. D. Palmer, while giving a deaf Palmer in 1895, to more than a hun- negro named Harvey Lilliard a mag- dred schools, over 20,000 practition- netic treatment, noted a lump on his ers and millions of converts to the back and pushed on the lump and the science in 1922. hearing returned. Impressed with It requires performance to convert the results obtained in this case, he millions of people and to win place. examined the spines of all his pat- power and prestige in a community ients for irregularities, and experi- infested with opposition, miseduca- mented with adjusting them. The tion and prejudice. It requires more results were that an astonishing per- than bombast and profession to he centage of so- called chronic and in- acquitted by juries when prosecuted. curable cases recovered. He studied and to inscribe laws favorable to Chi- some, but being old and tired and ropractic on the statute books of pretty well satisfied with his results state after state.
Load more

Recommended publications
  • Crystal Radio Set Systems: Design, Measurement, and Improvement Volume II a Web Book by Ben Tongue
    Crystal Radio Set Systems: Design, Measurement, and Improvement Volume II A web book by Ben Tongue First published: 10 Jul 1999; Revised: 01/06/10 i NOTES: ii 185 PREFACE Note: An easy way to use a DVM ohmmeter to check if a ferrite is made of MnZn of NiZn material is to place the leads of the ohmmeter on a bare part of the test ferrite and read the The main purpose of these Articles is to show how resistance. The resistance of NiZn will be so high that the Engineering Principles may be applied to the design of crystal ohmmeter will show an open circuit. If the ferrite is of the radios. Measurement techniques and actual measurements are MnZn type, the ohmmeter will show a reading. The reading described. They relate to selectivity, sensitivity, inductor (coil) was about 100k ohms on the ferrite rods used here. and capacitor Q (quality factor), impedance matching, the diode SPICE parameters saturation current and ideality factor, #29 Published: 10/07/2006; Revised: 01/07/08 audio transformer characteristics, earphone and antenna to ground system parameters. The design of some crystal radios that embody these principles are shown, along with performance measurements. Some original technical concepts such as the linear-to-square-law crossover point of a diode detector, contra-wound inductors and the 'benny' are presented. Please note: If any terms or concepts used here are unclear or obscure, please check out Article # 00 for possible explanations. If there still is a problem, e-mail me and I'll try to assist (Use the link below to the Front Page for my Email address).
    [Show full text]
  • Before Valve Amplification) Page 1 of 15 Before Valve Amplification - Wireless Communication of an Early Era
    (Before Valve Amplification) Page 1 of 15 Before Valve Amplification - Wireless Communication of an Early Era by Lloyd Butler VK5BR At the turn of the century there were no amplifier valves and no transistors, but radio communication across the ocean had been established. Now we look back and see how it was done and discuss the equipment used. (Orininally published in the journal "Amateur Radio", July 1986) INTRODUCTION In the complex electronics world of today, where thousands of transistors junctions are placed on a single silicon chip, we regard even electron tube amplification as being from a bygone era. We tend to associate the early development of radio around the electron tube as an amplifier, but we should not forget that the pioneers had established radio communications before that device had been discovered. This article examines some of the equipment used for radio (or should we say wireless) communications of that day. Discussion will concentrate on the equipment used and associated circuit descriptions rather than the history of its development. Anyone interested in history is referred to a thesis The Historical Development of Radio Communications by J R Cox VK6NJ published as a series in Amateur Radio, from December 1964 to June 1965. Over the years, some of the early terms used have given-way to other commonly used ones. Radio was called wireless, and still is to some extent. For example, it is still found in the name of our own representative body, the W1A. Electro Magnetic (EM) Waves were called hertzian waves or ether waves and the medium which supported them was known as the ether.
    [Show full text]
  • Radio Digest, 1924-1925
    B64714 6 DEC 271924 Aerial Aids for Christmas Set Buyers—J. E. Owen; New Het-duo-gen Circuit; "X" Wire—Key to Neutrodyne Success ; Details of $1,000.00 Gold Award Set Radio Di EVERY m= PROGRAMS TEN I CENTS REG. U. S. PAT. OFF. & DOM. OF CANADA \/,J YT Copyright 1924 VOl. -A.1 By Radio Digest Publishing Co. SATURDAY, DECEMBER 27, 1924 No. 12 NEW SET—FIND OF YEAR HET-DUO-GEN TUNES EITHER COAST EASILY Selectivity C. E. Brush Uses Six Tubes in Decidedly New Hook-Up —Tells How to Build Meet the Het-duo-gen! The set that really brings in what you want when you want it has come to light at last. A complete surprise be- cause its development is so different from the lines along which most ex- perimenters were known to be working. Combining the advantages of the hetero- dyne with regeneration on two tubes, C. E. Brush, of Chicago, has achieved a degree of selectivity that is almost miraculous. The sensitivity seems con- sistently to equal that of an eight tube PHONE CONNECTION super-heterodyne while the volume from three stages of audio frequency ampli- fication is more than enough for dancing. LONDON -NEW YORK A large loud speaker is required to handle it. Once the circuit is explained and the NEW STATION READY FOR operation understood, it all seems so simple that one wonders why it hasn't SERVICE NEXT YEAR been done before. Cost? The cost to (Continued on page 2) Will Use 4,000,000 Watts Power for Transoceanic Talking—Toll Charge Approximately $25 LONDON, Eng.—It is not only possible, but absolutely certain that in a year's time, any man in England can pick up the ordinary telephone in his house and speak to a friend in New York.
    [Show full text]
  • DESIGNING a DX CRYSTAL SET Equipment
    DESIGNING A DX CRYSTAL SET by Mike Tuggle 46-469 Kuneki St. Kaneohe, HI 96744-3536 E-Mail: [email protected] Long distance reception with crystal radios is once again becoming a serious pursuit among hams and other radio hobbyists. They are discovering that the DX capabilities of these receivers have been greatly underrated. I've been particularly interested in crystal sets since 1959, when I first discovered you could actually DX with them. The Internet has aided crystal set DX activity by making exchange of ideas between like- minded enthusiasts much, much easier. This article only touches the surface from a personal perspective. The reader is encouraged to pursue the online resources, described below, covering all aspects and providing further examples of this fascinating hobby. In this article I'll cover general design considerations for building DX crystal sets, but will leave the actual construction specifications up to you. Equipment Figures 1 and 2 show an example of a DX crystal set. I call it the "Lyonodyne-17." The design evolved from an earlier version described in the November, 1978 OTB. As you can see, this is not your grandfather's crystal set. Antenna (right) and detector (left) tuners are mounted on the middle board. Wave traps are located fore and aft on separate boards, making it possible to adjust the coupling by moving the boards. The antenna coil (L1) is wound on a short ferrite rod. The matching transformer unit for my RCA "Big Cans" sound powered phones is at front, left. So, what makes a crystal radio a "DX" set? Well, this one is double-tuned (L1-C1 and L2-C2) for selectivity to tune weak DX stations in the RF jungle we now live in.
    [Show full text]
  • The Crystal Radio
    The Crystal Radio: An Inexpensive Form of Mass Communication Christopher Manxhari Massachusetts Academy of Math & Science at Worcester Polytechnic Institute Manxhari 1 Introduction Technology has always been developing, and with it so have methods and access to communication. One such example is the internet, which has been rapidly growing in the past years. Yet, despite all of these advancements, there is still a large population that lacks internet. During distraught times, such as the coronavirus pandemic, having access to information is important, but not everyone is able to access urgent information. Roughly 10% of the United States population does not have access to the internet (Anderson, Perrin, Jiang, & Kumar, 2020). This proportion translates to over 30 million United States citizens, which is quite a substantial population size. In fact, there appears to be a correlation between income level and the proportion of those in a certain economic bracket that have internet. At an annual income of less than $30,000, 18% of citizens lack access to the internet. Withal, 7% of those making between $30,000 and $50,000 annually, 3% of those making $50,000 to $75,000 annually, and 2% of those making anything upwards annually lack that access (Anderson ​ ​ et al., 2020). See Figure 1 for more data on the ​ ​ ​ ​ demographics of those using the internet. It is evident that one’s income level is positively correlated with higher frequencies of internet usage. The internet is but one of many mediums of mass communication, and it is certainly one dominating form. As of 2018, roughly 41% of U.S.
    [Show full text]
  • Construction and Operation of a Simple Homemade Radio Receiving Outfit
    Construction and Operation of a Simple Homemade Radio Receiving Outfit The 1922 Bureau of Standards publication, Construc- tion and Operation of a Simple Homemade Radio Receiving Outfit [1], is perhaps the best-known of a series of publications on radio intended for the general public at a time when the embryonic radio industry in the U.S. was undergoing exponential growth. While there were a number of earlier experiments with radio broadcasts to the general public, most histori- ans consider the late fall of 1920 to be the beginning of radio broadcasting for entertainment purposes. Pittsburgh, PA, station KDKA, owned by Westinghouse, received its license from the Department of Commerce just in time to broadcast the Harding-Cox presidential election returns. In today’s world where instant global communications are commonplace, it is difficult to appreciate the excitement that this event generated. Fig 1. The crystal radio described in Circular 120. News of the new development spread rapidly, and interest in radio soared. By the end of 1921, new broad- casting stations were springing up all over the country. Radios were selling faster than companies could manu- facture them. The demand for information on this new technology was almost insatiable. The Radio Section of the Bureau of Standards provided measurement know- how to the burgeoning radio industry as well as general information on the new technology to the public. Letters to the Bureau seeking information on radio technology began as a trickle, and then soon became a flood. Answering them became a burden. Circular 120, published in April 1922, began: “Frequent inquiries are received at the Bureau of Standards for information regarding the construction of a simple receiving set which any person can construct in the home from materials which can be easily secured.
    [Show full text]
  • A Stable, Low-Noise Crystal Oscillator for Microwave and Millimeter-Wave Transverters
    A Stable, Low-Noise Crystal Oscillator for Microwave and Millimeter-Wave Transverters Would you like to try narrow-band modes in the gigahertz bands? If so, you’ll need a very stable and ultra-clean local oscillator. This project fills that need. By John Stephensen, KD6OZH mateurs are using narrow- than at lower microwave frequencies. commercial equipment on nearby fre- band modulation—including On SSB, the indicated frequency quencies or amateur beacons operating ACW, SSB and NBFM—on ever- should be within 500 Hz at both the at the same site. higher frequencies. In the US, SSB is transmitter and receiver, or you may I decided to replace the LO in my commonplace on all microwave bands not hear the station calling you. Dur- 24-GHz transverter and solve both the through 10 GHz and is spreading to ing a microwave contest, you don’t phase-noise and stability problems. the 24- and 47-GHz millimeter-wave want to adjust both the antenna and This article describes the crystal oscil- bands. In Europe, narrow-band opera- the frequency while trying to make a lator and multiplier designs that re- tion has taken place as high as contact. I wasted many hours during sulted. They work nicely with existing 411 GHz.1 the last 10-GHz-and-Up contest be- transverters using the KK7B LO The local oscillator (LO) used at cause the LO in my transverter was design2 with a few modifications and these higher, millimeter-wave fre- 85 kHz off frequency at 24.192 GHz. can be adapted to others.
    [Show full text]
  • Build a Crystal Radio: Electronics Series - Part I
    The University of Maine DigitalCommons@UMaine General University of Maine Publications University of Maine Publications 1965 Build a Crystal Radio: Electronics Series - Part I University of Maine Cooperative Extension Service Follow this and additional works at: https://digitalcommons.library.umaine.edu/univ_publications Part of the Higher Education Commons, History Commons, and the Radio Commons Repository Citation University of Maine Cooperative Extension Service, "Build a Crystal Radio: Electronics Series - Part I" (1965). General University of Maine Publications. 286. https://digitalcommons.library.umaine.edu/univ_publications/286 This Monograph is brought to you for free and open access by DigitalCommons@UMaine. It has been accepted for inclusion in General University of Maine Publications by an authorized administrator of DigitalCommons@UMaine. For more information, please contact [email protected]. UNIVERSITY OF MAINE LIBRARY COOPERATIVE EXTENSION SERVICE • UNIVERSITY OF MAINE, O r o n o ELECTRIC GUIDE SHEET OUTLINE A-21 (Advanced) BUILD A CRYSTAL RADIO ELECTRONICS SERIES - PART I lectronics is a fascinating hobby or a prof­ E itable lifetime occupation. Radio, apart of electronics, had its begin- ning about 1895 when Marconi succeeded in transmitting a "wireless" message over a distance of a mile and a half. Marconi did not invent radio, nor was he alone in its early work. However, from that small beginning radio has advanced until to- day its influence is felt in every phase of our lives. Through radio and television the world's greatest entertainers, educators, and poli­ ticians virtually step into our living room. Electronics provides communications across continents, oceans and into outer space.
    [Show full text]
  • Crystal Radio Engineering
    Crystal Radio Engineering A web book by Kenneth A. Kuhn updated Apr. 17, 2008 i ii A SIMPLE CRYSTAL RADIO PREFACE ADVANCED TOPICS This is a collection of articles that form a text book on designing crystal radios. The primary focus is to illustrate to A chapter on making various measurements of your system is engineering students how to apply concepts of engineering to planned. Some other chapters or additional information is solve a problem. It takes a lot of in-depth research to be good planned to connect all the chapters together smoothly. Right at what one does. The main part of this book deals with now the connections are rough -- but this is a work in progress. understanding the required concepts to build a good basic crystal radio. Advanced concepts (to be written and posted last) will deal with a number of improvements that can be made to the basic design. Here is a link to an excellent site for crystal radio information: http://www.crystalradio.net/crystalplans/index.shtml http://www.1n34a.com/ This is an excellent site with links to other crystal radio sites. Be sure to check the Ben Tongue link for a number of practical articles. Here is a source for parts I found using a Google search http://www.midnightscience.com/catalog5.html#part2 This company specializes in parts for crystal radios and sells variable capacitors, diodes, crystal earphones, etc. I have not bought from them before so I do not know how good they are but I might try them someday. The following are links to the pdfs for each chapter.
    [Show full text]
  • Radio Electronics, July 1986 with an Article That
    7A 3v7 Most us believe that the age of solid- MARTIN CLIFFORD DID YOU KNOW: TI IAT SOLID-STATE ELEC- of tronics can trace its roots back to 1835? state electronics began with the invention In this, the first installment That radio signals can be demodulated of the transistor; Bardeen and Brattain of using sulfuric acid or nitric acid? That oil - Bell Laboratories produced that first crys- of our new, occasional series filled variable capacitors were once used tal triode in 1948. However, lost in the about the early days of radio, in radio receivers? That a single crystal mists of history is the fact that true solid- detector can be used as a radio receiver? state receivers have been with us since we look at the original That there are some radio receivers that about 1918. "solid-state" receivers. never need to be turned off, have no on/off In more recent times, the term solid- switch, and do not require battery or AC state has been so firmly associated with power? Or that lenzite, zincite, bornite, germanium, and subsequently with sil- tellurium, and chalcopyrite are all semi- icon, that no one should be blamed for conductors? thinking that those are the only materials The Early Days o 1 i I y m y,o- .. J' -, - suitable for use in semiconductors. Yet least some improvement over those with there are numerous materials that are just no tuning at all. as suitable. Among them are carhorun- Another problem was that the output of dum (silicon carbide): galena (a crystal the crystal detector consisted of both an sulphide of lead); molybdenum: lenzite: audio signal and an RF carrier: both were ¿incite (an oxide of zinc): tellurium: bar- passed directly to the headphones.
    [Show full text]
  • ED426693 1999-03-00 Radios in the Classroom: Curriculum Integration and Communication Skills
    ED426693 1999-03-00 Radios in the Classroom: Curriculum Integration and Communication Skills. ERIC Digest. ERIC Development Team www.eric.ed.gov Table of Contents If you're viewing this document online, you can click any of the topics below to link directly to that section. Radios in the Classroom: Curriculum Integration and Communication Skills. ERIC Digest........................................................... 2 TEACHING THE HISTORY OF COMMUNICATION..................... 2 AM-FM RADIO: HANDS-ON GEOGRAPHY AND LANGUAGE ARTS ACTIVITIES................................................................ 2 INTERNATIONAL SHORTWAVE BROADCASTS: HEARING THE WORLD ON A RADIO....................................................3 NOAA NATIONAL WEATHER SERVICE BROADCASTS.............. 3 AMATEUR RADIO: PRACTICING HANDS-ON COMMUNICATION SKILLS...................................................................... 4 SUMMARY.......................................................................4 REFERENCES.................................................................. 4 ERIC Identifier: ED426693 Publication Date: 1999-03-00 Author: Ninno, Anton Source: ERIC Clearinghouse on Information and Technology Syracuse NY. Radios in the Classroom: Curriculum ED426693 1999-03-00 Radios in the Classroom: Curriculum Integration and Page 1 of 8 Communication Skills. ERIC Digest. www.eric.ed.gov ERIC Custom Transformations Team Integration and Communication Skills. ERIC Digest. THIS DIGEST WAS CREATED BY ERIC, THE EDUCATIONAL RESOURCES INFORMATION CENTER. FOR MORE
    [Show full text]
  • SUPERHETERODYNE CONVERTORS and 1-F AMPLIFIERS
    ELECTRONIC TECHNOLOGY SERIES SUPERHETERODYNE CONVERTORS and 1-F AMPLIFIERS ,#.,_. •~· .• :· :-,:·,' . ...~ ' ' ' . ' ,\,.. • · ,, . ,·;, . :; ~: ~, :· ,. ~: '.·· .. '. •'.~ ;·. '~ . ' . ., . :• a publication SUPERHETERODYNE CONVERTERS AND 1-F AMPLIFIERS Edited by Alexander Schure, Ph. D., Ed. D. JOHN F. RIDER PUBLISHER, INC., NEW YORK a division of HAYDEN PUBLISHING COMPANY, INC. Copyright IC 1963 JOHN F. RIDER PUBLISHER, INC. All rights reserved. This book or any parts there may not be reproduced in any form or in any language without permission. SECOND EDITION Library of Congress Catalog Number 6J-20JJ6 Printed in the United States of America PREFACE The utilization of heterodyning action in receiver design via local oscillator, mixer, or converter action marks one of the major steps in the advance of communications. Application of the basic prin­ ciples of superheterodyne operation solved many of the problems inherent in the earlier tuned radio frequency receivers. Such factors as receiver stability, gain, selectivity, and uniform bandpass over an entire band could be improved by using the superheterodyne receiver. The reasons for the enormous popularity of this design are apparent, as is the need for the technician to understand the theory and operation of superheterodyne converters and i-f ampli­ fiers. This book is organized to provide the student with an under­ standing of these fundamental principles, with emphasis on the descriptive treatment and analyses. Mathematical formulas or numerical examples are presented where pertinent and necessary to illustrate the discussion more fully. Specific attention has been given to the essential theory of mixers and converters; basic superheterodyne operation; arithmetic selec­ tivity; image frequency considerations; double conversion; conver­ sion efficiency; oscillator tracking; pulling and squegging; types of converters (both early and modern) ; functions and design factors of i-f amplifiers; choices of i-f frequencies; ave and davc; the Miller effect; and the consideration of alignment procedures.
    [Show full text]