DOCSLIB.ORG

A Practical Neutrodne Receiver by ALLAN T

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Practical Neutrodne Receiver by ALLAN T Radio News for January, 1924 899 A Practical Neutrodne Receiver By ALLAN T. HANSCOM This article explains the action of the neutrodyne circuit in a manner which can be grasped by the novice. Its formation is described stage by stage, followed by complete constructional details for the building of a receiver of this type. on which the secondary coil is wound. It is difficult to buy one tube to fit inside an- other in this manner, but it can be overcome by sawing a piece of tube /" wide length- wise from the same tubing. Then when it is wound, the wire will draw it to a smaller diameter whereupon it may be slid into place inside the full sized tube. It is very im- portant that these transformers be mounted Insulated wire fig. 2 /w/sted together A One -Stage Radio Frequency Amplifier and a Non- Regenerative Detector, the Respective Secondary Circuits of Which Are Tuned by Means of Variable Condensers. IT is unfortunate that so many good cir- the neutrodyne after we add the neutralizing cuits are labeled with such formidable condensers which will be considered later. titles. The name "neutrodyne" is usu- In Fig. 3, there are two stages of radio ally enough to scare the average radio frequency amplification and the detector, fan. A neutrodyne circuit, as commer- each stage being tuned by a variable conden- cially developed, is, however, a great deal ser in the grid circuit. This circuit would more simple to understand than the regen- give wonderful results if it were not for the erative or reflex circuit. internal capacity coupling between the plate and the grid circuit of each radio frequency Bus wire Meta/ frbe tube. This internal capacity is neutralized by the combination of capacity and induct- ance; the inductance being the windings of the air core radio frequency transformers R. fig. d The capacity necessary for the average vacuum tube is very small and is usually Several Ways of Making the Neutralizing Capac- about equal to two circular plates /" in ities. diameter separated by 3/32 of an inch. This is only approximate and the proper value may at least 6" apart and at such an angle that easily be found. Other types of condensers a line drawn at right angles to the axis at for this purpose are shown in Fig. 4. the end of the winding does not intersect The radio frequency transformers can be the winding of the adjoining transformer. made by winding 80 turns of wire on 3" tubes See Fig. 6. Note the relative position of Two -Circuit Non -Regenerative Receiver Having a Tuned Secondary Circuit. with a tap taken off at the 20th turn. It is primary and secondary windings. The average fan is not interested in the higher mathematics of a circuit but he does like to know the size of the parts so that he can put one together to obtain results. Fig. 1 represents a simple type of non -re- generative hook -up. By varying the conden- ser the natural wave -length of the set can be altered. This is exactly the diagram of the first stage of the neutrodyne. In Fig. 2, another stage exactly like the first has been added. In this case the first tube acts as a radio frequency amplifier and the second tube as a detector. fig 3 It will be noticed that the plate circuit of Two Stages of Tuned Radio Frequency Amplification and Detector. These Circuits Are Free to the first tube is not tuned, but that the grid Oscillate Due to Feed Back Through the Internal Capacity of the Tubes. circuit of the second tube, as well as the grid circuit of the first tube, are both tuned and preferable to use cardboard because it is an NEUTRALIZING CONDENSERS in reality make the two stage filter through advantage to have a close coupling between Since the variable condensers used are con- which the incoming signal must pass. this coil and the primary, which is inserted nected between the grid and the filament, it Fig. 3 represents three stages exactly as inside. The primary consists of 20 turns of is possible to connect the grid to the fixed outlined above and this is the scheme of wire on a tube which will just clear the tube plates and then mount the other small mov- able plate on the back insulated portion of .002 M.f the condenser. By this means a very small change of capacity can be made in the neu- Vh0rIe5 tralizing circuit. See Fig. 7. t meg0lim After the proper value of this capacity is I found, it need never be disturbed unless tubes 1.1222 are changed. It is likewise advantageous to + 5in shield the set, although it is absolutely im- M.f possible to make this set oscillate if it is .005 properly constructed. To find the proper value of the neutraliz- ing condensers it is necessary to tune the set -B to a very powerful signal. The Flewelling .0005 A "screamer" makes an excellent oscillator for o this case. A paper may be inserted in the socket to cover the filament connections but fig. 8 leaving the plate and the grid free. Then the tube is inserted and the signal is still Complete Circuit Diagram of a Neutrodyne Receiver Having Two Stages of Tuned Radio Frequency heard. Amplification and Detector. The Circuit is Kept from Oscillating by Means of Small Condensers Which Neutralize the Capacity of the Tubes (Continued on page 914) www.americanradiohistory.com 914 Radio News for January, 1924 1.1.1117-MrMliiillummilnIFIIIIIITIllummIlmmuilnIIIMIM II 111 rimonmovanimmummantme Eliminating Interference __ (Continued from page 898) E .1,,,,11,,,,,,,,,,.1,111,1111111111111,,,,,1,111111,1111,111,,,1,,,,,,1,,,,,1,,,,1,111,111111111,1111,1,111111111,,,,,,,,1 TIC ,,,111° E upreme sharply with the single and multiple turn upreme switches of the tuner. This is in effect an LOUD SPEAKER. air core transformer coupled amplifier and HEAD SETS is equally effective over the entire range of the tuner. The resultant complete circuit is shown in Fig. 2. ADAPTED TO SINGLE CIRCUIT TUNERS For single circuit tuners the amplifier shown in Fig. 3 has proven very effective. As in the first case the output of the am- plifier is connected to the input of the tuner. When a receiver such as an R.C. is used where the tuning elements are in one cabinet and the tubes in another, busses connect the two. The post marked "G" in Fig. 3 con- nects to the post marked "Grid" on the tuner. When the tuner has no outside connections, such as in an Aeriola Senior, a separate wire is run from the grid lead inside the tuner to "G ". On some sets it is necessary to re- move the grid leak when it is connected around the grid condenser instead of to the filament. This arrangement makes a tuned imped- ence coupling between the first two tubes No extra Batteries The Head Set required. that is Always Ahead Finely and as accurately made as a high -priced watch and fig. 4 there you have the whole A Regenerative Circuit Employing One Stage story of Tuned Radio Frequency Amplification to In- crease Selectivity and Distance and to Prevent Re- of BERWICK Headset su- At LAST. radiation. premacy. and is shown below with the detector in Fig. 4. Every BERWICK Headset A Perfect Loud It is not necessary to install this apparatus is perfectly matched for tone Speaker With a in a cabinet, as very excellent table mounted instruments are available. The parts used - TESTED in ACTUAL MICROMETER are : 1 Variometer use for clarity and reproduc- Adjuster and Tuner 1 Potentiometer tivity, and sold with an uncon- 1 Rheostat This remarkably powerful special Unit with the marvelous MICROMETER Adjuster, gives 1 Socket ditional guarantee, or your you -with just the turn of a little knob -maxi- 1 .00025 M.F. Fixed Condenser mum clearness, and a ready ability to meet 1 Amplifier Tube. money back. every individual condition as easily, as simply as you would adjust a pair of opera glasses to I feel confident that any reader who will suit your own vision. spend the few dollars necessary to install 2200 ohms-$5.00 FIBRE HORN, non -resonant, non -breakable, either of the amplifiers will be well paid by damp- proof. TWICE TESTED in actual radio the in his I know 3000 ohms -$6,00 reception before it reaches your hands. improvement set and will SEALED to prevent tampering. UNCON- be blessed by his neighbors. DITIONALLY GUARANTEED FOR A BUY A BERWICK Su- YEAR against any defects. t,.1,,,11,111111111111,111,,,,,,,,,,n,11.,m11M1,,,,,,,,1,1,11,,,,11,M7M,.,1,7M. ,,,M1,11111111, Here indeed is the Loud Speaker that brings preme Headset TODAY you everything you want to hear - clearly, - faithfully -from the most delicate shadings of A Practical Neutrodvne and note the difference. the human voice to the rich, full blare of a great brass band. É Receiver At All Reliable Dealers Convince Yourself- (Continued from page 899) =- Get Yours TODAY. Sold Through Jobbers If your dealer cannot supply you, get in touch with us direct. This is done for the first stage and second DEALERS: Ask your jobbers for information. stage separately, adjusting each condenser TRIANGLE until the signal is no longer heard. I have found it possible to adjust these condensers Electro Trading Co., Inca TRIANGLE without going to this trouble by simply set- Manufacturers Co., Inc. ting them at the greatest capacity which 632 -634 Broadway, New York Electro Trading would not cause the set to go into an oscillat- Manufacturers New York Chicago Minneapolis ing condition.
Load more

Recommended publications
  • Vintage Radio
    VINTAGE RADIO Building a vintage radio "replica" Have you always wanted a 1920s or 1930s lacquer finish of some sort. Second, a glance at the front panel reveals that "cathedral" style radio. They're as scarce as these sets can receive FM transmis- sions as well as AM. In reality, FM hens' teeth these days - or are they? If you didn't get under way in Australia un- can't get an original, what about one of the til well after the era that the "replica" is supposed to represent. many replicas now coming onto the market? However, it's not until you expect the "insides" of such radios that you From time to time, "replicas" of ites but of course, they're not true realise just how far away they are early radio sets appear in catalog ad- replicas. First, the cabinets are noth- from being a true replica of the era. vertisements from various electronics ing like the those from the 20s, 30s Hidden inside the cabinet will be a and electrical retailers. Consoles and and 40s, usually being made from small transistor radio and that's hardly cathedral sets seem to be the favour- cheap ply or particle board with a something that was around in the 1920s or 1930s! So these sets are in no way an accu- rate copy or replica of any early radio. The fact is, there are very few genu- ine 1920s (and not many more 1930s) sets now available on the market. Many collectors will never own ra- dios of this vintage.
    [Show full text]
  • 1994-11: Browning-Drake
    Vii luta gic IRaidl iio by PETER LANKSHEAR The Browning-Drake receiver One of the best remembered radio names from the 1920's is 'Browning-Drake', a receiver which combined simplicity with what for its time was a rate performance. While most of its contempo- raries had production lives of little more than a year, the Browning-Drake design was popular for much of the decade. As with the IBM personal computer'. it. recently, there were also more 'clones' made by others than the official versions... By the outbreak of World War I, valve cluding them in tuned circuits coupling The alternative method, and of course receiver technology had advanced to the the valves. However the tuned RF ampli- the ultimate solution to many difficulties stage where stable detection and low fre- fier then ran into another problem. Tri- was the superheterodyne, attributed by quency amplification were possible. ode valves have sufficient inter-ekctrode Americans to work done in 1918 by Ma- However there were limitations to the capacitance that with tuned circuits con- jor Edwin Armstrong of the US Army. sensitivity and selectivity of the grid leak nected to both anode and grid, there is While much credit is due to Armstrong, it detectors that had become standard. sufficient energy transferred internally is now clear that the original concept of The newly discovered regeneration back to the grid to cause them to become the superhet was an international effort, helped, but it became clear that the only vigorous oscillators. with much of the early work being done way to improve receiver sensitivity was Initially there were two solutions.
    [Show full text]
  • Man of High Fidelity
    Man of High Fidelity: EDWIN HOWARD ARMSTRONG A Biography – By Lawrence Lessing With a new forward by the author Page iii Pratt DISCLAIMER DISCLAIMER TO THIS SCANNED AND OCR PROCESSED COPY This PDF COPY is for use at Pratt Institute for Educational Purposes Only I affirm that sufficient print copies of the original Bantam Book Paperback are in stock in ARC E-08 that would more than adequately cover a full class use of the text. HOWEVER, due to the fact that the 1969 text is no longer in publication, complicated by the fact that these copies are forty-four (44) years old and in a very fragile condition, this PDF version of the text was created for student use in the Department of Mathematics and Science. - Professor Charles Rubenstein, January 2013 Man of High Fidelity: Edwin Howard Armstrong EDWIN HOWARD ARMSTRONG Was the last – and perhaps the least known – of the great American Inventors. Without his major contributions, the broadcasting industry would not be what it is today, and there would be no FM radio. But in time of mushrooming industry and mammoth corporations, the recognition of individual genius is often refused, and always minimized. This is the extraordinary true story of the discovery of high fidelity, the brilliant man and his devoted wife who battled against tremendous odds to have it adopted, and their long fight against the corporations that challenged their right to the credit and rewards. Mrs. Armstrong finally ensured that right nearly ten years after her husband’s death. Page i Cataloging Information Page This low-priced Bantam Book has been completely reset in a type face designed for easy reading, and was printed from new plates.
    [Show full text]
  • Journal Vol 9-X 1985
    Ctil?~ ()fflclal JI ~()IU IV~ A\ IL JAN - MAR 1985 CALIFORNIA HISTORICAL RADIO SOCIETY PRESIDENT: NORMAN BERGE SECRETARY: BOB CROCKETT TREASURER: JOHN ECKLAND EDITOR: HERB BRAMS PHOTOGRAPHY: GEORGE DURFEY CONTENTS CLUB NEWS •••••••••••••••••••••••••••••••••••••••••••••••• • . l THE SUPERHETERODYNE RECEIVER ••••••••••••••••••••••••••••••• 3 WHAT KIND OF COLLECTOR ARE YOU? •••••••••••••••••••••••••• 20 BALLAST TUBES AND RESISTANCE LINE CORDS ••••••••••••••••••• 21 ADVERTISEMENTS •••••••••••••••••••••••••••••••••••••••••••• 24 THE SOCIETY ll\e California Historical Radio Society is a non-profit corporation chartered in 1974 to promote the preservation of early radio equipment and radio broadcasting. CHRS provides a meditDD for members to exchange infor­ mation on the history of radio with emphasis on areas such as collecting, cataloging and restoration of equipment, literature. and programs. Regular swap meets are scheduled four times a year. For further information, write the California Historical Radio Society, P. O. Box 1147, Mountain View , CA 94042-114 7. THE JOURNAL ll\e official Journal of the California Historical Radio Soc i ety i a published six times a year and is furnished free to all members. Articl e• for the Journal are solicited from all members. Appropriate subjects include information on early radio equipment. personalities, or broadcasts, restoration hints, photographs, ads, etc. Material for the Journal should be sulrnitted to the Editor, Herb Brams, 2427 Durant #4, Berkeley, CA 94704. MEMBERSHIP Membership correspondence should be addressed to the Treasurer, John Eckland, 969 Addison Ave., Palo Alto, CA 94301. CHRS SWAP MEETS CHRS swap meets have tentatively been set for the following dates: June 1, Aug. 31, and Nov. 9 at Foothill College. Notices will be sent if these dates are changed.
    [Show full text]
  • Alignment and Neutralization of the Early Ac Trf & Neutrodyne Receivers
    ALIGNMENT AND NEUTRALIZATION OF THE EARLY AC TRF & NEUTRODYNE RECEIVERS by Lane S. Upton 3788 S. Loretta Dr. Salt Lake City, UT 84106-2956 For a radio to work as it was originally designed, it must be in proper alignment. This means that at any single point on the dial all tuned circuits must be at resonance and the dial calibration should be correct. In the case of neutrodyne receivers, additional steps must be taken to assure that each neutralized amplifier stage is adjusted properly. This will assure that the full gain can be realized. The purpose of this article is to provide a detailed review of the steps necessary to completely align these receivers. Much was written on this subject when the radios were relatively new, but it was all directed toward working on a "modern" receiver only a few years old. Today, we must look at warped variable condensers, worn wiper contacts, poor ground connections, coil windings that have shifted position, incorrectly positioned coils, loose shield cans, and many other problems brought about by age and abuse. The time spent doing a complete alignment will typically result in a radio with greatly improved selectivity and sensitivity. This is especially true at the lower frequency portion of the dial. Preliminary Work The initial work on a set must include inspection of all the components that will affect alignment. This should not be limited to the variable condenser and coils, but must include all other items that can have any effect. The following steps represent a basic outline of the preliminary work that should be carried out.
    [Show full text]
  • Radio Broadcast
    RADIO BROADCAST WILLIS KINGSLEY WING, Editor OCTOBER, 1927 KEITH HENNEY EDGAR H. FELIX Vol. XI, No. 6 Director of the Laboratory Contributing Editor =* AMO7S[G OTHER THINGS. - - - - Cover Design From a Design by Harvey Hopkins Dunn MUCH is now being accomplished in the complete set SOfield that beginning with this issue, RADIO BROADCAST Station the Frontispiece The Most Powerful Broadcasting in World 340 will devote much of its space to reflecting the technical and other advances being made. The policy of this magazine remains as Now You Can Receive Radio Pictures - - Keith tienney 341 before, to present the news of radio surrounded by as much as of what the technical radio worker refers to as The March of Radio An Editorial possible "dope." Interpretation 344 And much "dope" there is in this complete set side of radio as Modern Radio Receivers are a Good Invest- The of Direct on the Danger Advertising Air articles which will in issues will ment The Month in Radio many appear following strikingly demonstrate. In all the other fields of radio endeavor Listening to World-Wide Broadcasting is Licenses and What They Mean which Near The Columbia Broadcasting Chain RADIO BROADCAST has covered heretofore the construction A Profound Study of Radio Law of radio receiving apparatus, laboratory experiments, short- - wave communication, from the technical and The 1928 "Hi'Q" Has an Extra R. F. Stage John B. Brennan 348 broadcasting program side, and many others which we have covered to Manufactured Receivers for the Coming Season - - - 351 the satisfaction of our readers, RADIO BROADCAST will be as active as before.
    [Show full text]
  • Electronic Home Music Reproducing Equipment
    Electronic Home Music Reproducing Equipment Daniel R von Recklinghausen Copyright © 1977 by the Audio Engineering Society. Reprinted from the Journal of the Audio Engineering Society, 1977 October/November, pages 759...771. This material is posted here with permission of the AES. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the AES by contacting the Managing Editor, William McQuaid., [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it. John G. (Jay) McKnight, Chair AES Historical Committee 2005 Nov 07 Electronic Home Music Reproducing Equipment DANIEL R. VON RECKLINGHAUSEN Arlington, MA The search for amplification and control of recorded and transmitted music over the last 100 years has progressed from mechanical amplifiers to tube amplifiers to solid-state equipment. The AM radio, the record player, the FM receiver, and the tape recorder have supplemented the acoustical phonograph and the telephone. An incomplete summary of important developments in the past is presented along with challenges for the future. Home music reproduction began when Bell invented the tromechanical repeater caused it to be used for 20 years telephone in 1876 and Edison invented the phonograph in more as a hearing-aid amplifier [5, pp. 64-69]. 1877. Instruments were manufactured soon thereafter and C.A. Parsons of London, England, inventor of the leased or sold to the public. Yet the listener had very little Auxetophone, marketed in 1907 a phonograph where the control over the reproduction and the volume of sound, the playback stylus vibration caused a valve to modulate a tone quality being predetermined by the manufacturer of stream of compressed air which was fed to a reproducing the phonograph and record or by the telephone company horn [6].
    [Show full text]
  • Two Rich Minds - One Poor Invention
    Two Rich Minds - One Poor Invention by William E. Denk, W3IGU 1 Reprinted From The Antique Radio Gazette Volume 15, No 1 (Spring, 1987) An early patent by legendary inventors Edwin Armstrong and Michael Pupin confirms the former's long-time interest in reducing radio static. Though the application of regeneration to antenna circuits as a noise limiting technique was a dead end, it did foreshadow Armstrong's eventual development of Frequency Modulation. Writer Bill Denk was a long-time author of The OTB's book review column. Even before the founding of the first organizations devoted to the preservation of the wireless history and equipment, this writer had started his collection of patents having special significance in the early development of the communications technologies. The collection includes Edison's patent on the phonograph, Bell's patent on the telephone, the Morse patents on the telegraph, Marconi's earliest patents on his wireless transmitting and receiving system, Fleming's patent on the vacuum tube diode detector, the early crystal detector patents of Bose, Dunwoody, and Pickard, the Hazeltine Neutrodyne patent--hundreds in all. Collecting patents is an area of our hobby that requires very little space, and it can be most interesting and revealing. One of the early patents in my collection, added because of the eminence of the named co-inventors, might have been later discarded had the inventors been a pair of unknowns. One of the inventors was Michael I. Pupin, Professor of Mathematics at Columbia University. He was the inventor of the telephone repeater, or Pupin coil, which greatly improved long-distance land-line telephony.
    [Show full text]
  • One City—Two Giants: Armstrong and Sarnoff: Part 1
    dsp HISTORY Harvey F. Silverman [ ] One City—Two Giants: Armstrong and Sarnoff: Part 1 EDITOR’S INTRODUCTION Our guest in this column is Dr. Harvey F. Silverman. Dr. vation. An outgrowth of this passion is that of using his Silverman received his Ph.D. and Sc.M. degrees from Brown knowledge and engineering skills to develop intelligent University. He earned his B.S.E. and B.S. degrees from Trinity means for deterring the many furry and feathered creatures College in Hartford, Connecticut. He worked at IBM T.J. who very much like to share in the eating, although not the Watson Research Center in Yorktown Heights, New York, planting and cultivating. So far, the critters are winning! between 1970 and 1980. During these ten years, he worked As our author mentions at the beginning of this article, in on a number of projects related to image processing methods 1969 he bought the book Man of High Fidelity, which was a applied to earth resources satellite data, analytical methods 1969 paperback version of a 1956 biography of Edwin for computer system performance, speech recognition, and Howard Armstrong. The book was so intriguing that the development of a real-time I/O system as the manager of Dr. Silverman borrowed an autobiography of David Sarnoff. the Speech Terminal Project. In 1980, he joined Brown This was the beginning of a journey where our author University as a professor of engineering. From 1991 to 1998, learned about these two inventors and how such two strong he was the dean of engineering at Brown University.
    [Show full text]
  • Rado May03 1924 .Pdf
    2 Radio Doings Business Has Been So Good This Week That We Have'nt Found Time To Write An Ad KENNEDY ghc1Royally g' (Radio Ask Any Kennedy Dealer WHOLESALE ONLY KIERULFF & RAVENSCROFT 1630-1632 South Los Angeles Street, Los Angeles, Calif. Phones: ATlantic 3125-ATlantic 3303 1Rabio doings Phone TRinity 6062 H. C. CHARLES, Editor 1.T.PERDUN,Manager HALL BERRINGER, Technical Editor Branch Manager: R. L. CONNER, 703 Cunard Bldg., San Francisco, PhoneGarfield 4557 Advertising Representativest J. C. PENLEY J.B. SHILLINGFORD LEE FELTSKOG 308 Van Nuys Building Los Angeles, Calif (Entered assecond-classmatter,November 25, 1922, Los Angeles, California Post Office, Cinder Act of March 3, 1897) Copyright,1924,by Harwood PublishingCo. FiveCents a Copy Two Dollars a You. Vol. IV. Los Angeles, May 3, 1924 No. 18 National Music Week THE week of May 6th to 12th has bee designatedMusic Week.It is particu- larly fitting that the radio public should help tocelebrate this week.Radio and broadcasting without music would be like arailroad train without the engine or an automobile with no gasoline. Weshould all get tired in a very short time of listening in to just talk. Music, since the early days of history, has alwaysentered into the culture of all nations.Most countries have music that is distinctive.It is easy to distinguish an Italian, Spanish, Irish, Scotchair as soon as you hear it, and it seems to fit the natures of those inhabiting these countries.So we have music for all moods and fancies.Music can inspire us when we hear out nationalanthems, and can make us sad when we hear funeraldirges.
    [Show full text]
  • Reflex Radio Receivers 1924 Ocr.Pdf
    The "Experimenter's Library" 25c. Books Covering Every Branch of Radio Each book is written by a well-known author and con• tains 48 pages of valuable (••HM.TICAI. KflOlO information, fully illustrated. ftWf(U(Ni". r,fr.v Cover is in two colors, size 5/4 x7K inches. No. 1. Tips for the Radio Amateur Constructor. Hi No. 2. How to make Practical Radio No. 3. Receiving Set*. Radio Questions Answered. No. 4. Radio Frequency Amplification No. 5. Loud Talkers and How to Build Them. No. 6. IftAOlC QUESTION ALL ABOUT • How to Tune Your Radio Set. RADIO PARTS No. 7. 100 Radio Hook-ups. No. 8. All About Radio Parts. No. 9. History and Operation of the No. 10. Vacuum Tube. The Neutrodyne—All About It. No. 12. How to Locate Troubles in Your Radio Set. I © T«t(..^ Each 25c. Postpaid HOW TO TU«F. you ft f- flO.O SET THE CONSRAD COMPANY, inc. Selling Agents 233 FULTON STREET NEW YORK CITY THE EXPERIMENTER'S LIBRARY, No. 13 Reflex Radio eivers By P. E. EDELMAN TRADE Published by THE E. I. COMPANY 233 Fulton Street New York City Printed in the United State* of America Copyright by THE E. I. COMPANY 1924 All rights reserved, including: that of translation into foreign languages, including the Scandinavian INTRODUCTION. The growing popularity of reflex types of broadcast receivers is due to the efficient use of fewer vacuum tubes than equivalent outfits of different character re• quire. The reflex principle was proposed by Schloemilch and Von Bronk in their U.
    [Show full text]
  • The AWA Review
    The AWA Review Volume 26 • 2013 Published by THE ANTIQUE WIRELESS ASSOCIATION PO Box 421, Bloomfield, NY 14469-0421 http://www.antiquewireless.org Volume 26, 2013 i Volume 26 book.indb 1 14/06/2013 2:54:15 PM Devoted to research and documentation of the history of wireless communications. THE ANTIQUE WIRELESS ASSOCIATION PO Box 421, Bloomfield, NY 14469-0421 http://www.antiquewireless.org Founded 1952, Chartered as a non-profit corporation by the State of New York. The AWA Review EDITOR Robert P. Murray, Ph.D. Vancouver, BC, Canada ASSOCIATE EDITORS Erich Brueschke, BSEE, MD, KC9ACE David Bart, BA, MBA, KB9YPD, Julia Bart, B.A., M.A. FORMER EDITORS Robert M. Morris W2LV, (silent key) William B. Fizette, Ph.D., W2GDB Ludwell A. Sibley, KB2EVN Thomas B. Perera, Ph.D., W1TP Brian C. Belanger, Ph.D. OFFICERS OF THE ANTIQUE WIRELESS ASSOCIATION DIRECTOR: Tom Peterson, Jr. DEPUTY DIRECTOR: Robert Hobday, N2EVG SECRETARY: William Hopkins, Ph.D., AA2YV TREASURER: Stan Avery, WM3D AWA MUSEUM CURATOR: Bruce Roloson, W2BDR 2013 by the Antique Wireless Association, ISBN 978-0-9890350-0-2 Cover images are of cartons of tubes produced by E.B. Myers in Montreal in 1923-1925, (front cover) and of a tube produced by his factory in Cleveland in 1926, (back cover). Article begins on page 37. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopy- ing, recording, or otherwise, without the prior written permission of the copyright owner.
    [Show full text]