Old -TimeRadio · FROM AN ALBUM (Continued from preceding page) MacMillanListensto HonoluluLicen.red ',fader Armstrong V, S. Patent No. 1.114149. and NewZealand "TunesIn" California

Special Feature Pull -Out Section

Old -Time RadioHISTORICAL EVENTS IN ELECTRONICS

Edited byWilliam M. Palmer, W5SFE

BIOGRAPHICAL SKETCHES OF GREAT MEN HISTORY OF INVENTICN PICTORIAL HISTORY OF ELECTRONICS OLD-TIME RADIO PROJECTS NEWS OF HISTORICAL INTEREST

The human mind is sleepless in :he pursuit of knowledge.It is ever seeking new fields of conquest. It must advance;with it, standing still is the precursor of defeat.

-From History of Civilizationby E. A. AllenPubli;hed in 1891, by CentralPubli;hing House, Cincinnati,Ohio

Published by

Electronics Digest1024 Currie Street, Fort Worth, TX 76107

Copyright 1972 by Electronics Digest DivisionTandy Corperation

ELECTRONICS DIGEST for July/August 197213

N 1 a O

BIOGRAPHICAL SKETCHES OF GREAT MEN IN ELECTRONICS

Joseph Tykocinski Tykociner

Let us honor our men of scienceWho once walked upon the planet EarthAlong the uncharted trails of electronicsIn search of a better way of lifeFor all mankind

October 5, 187/ June 12, 1969

Electrical Engineer, Inventor, Educator

by William M. Palmer

Today's growing ethnic consciousness,although often billed as humanitarianin objectives, has the insidious effect ofsetting up tiny self-seeking nations with-in our nation.

When our forefathers came to Americathey gladly cast off the ties that boundthem to their mother country, and theymerged their knowledge and resourceswith that of settlers of many nationalorigins to achieve the common aim . . .

a new nation founded upon individualfreedom . . . and the opportunity forall to climb the highest mountain ofachievement. They believed in workingtogether for the common good.

Out of this heritage came men likeAlexander Graham Bell, Michael Pupin,Nikola Tesla, Charles Steinmetz, DavidSarnoff, Vladimir Zworykin . . . andcountless others including the subjectof this biographical sketch, Joseph Ty-kocinski Tykociner (Joe-seff Tick -oh -shin -sky Tick -oh -shiner).

Tykociner was born in Vloclavek,Poland, on October 5, 1877. A hundredyears before that, another great Polishfriend of America, during the Revolution,Count Casimir Pulaski, was distinguishinghimself at the battle of Brandywine as asoldier in the army of General GeorgeWashington. Count Pulaski fell mortallywounded during the siege of Savannah(Georgia) and died on October 11, 1779.

In recognition of his valor, a famousearly -day fort was named for him, FortPulaski, on Cockspur Island at themouth of the Savannah River, 17 mileseast of Savannah, Georgia. Today, it is apart of the U. S. National Park Systemwhich is dedicated to conserving thescenic, scientific, and historic heritageof the United States.

Unfortunately, the shifting sands ofdestiny erased the path to recognitionfor another great man of Polish ancestry,the subject of our biographical sketch,

Joseph Tykociner, who has been called"a man ahead of his time."

Tykociner experienced the same skep-ticism faced by many other inventorswhen mankind examines new ideas andinnovations which portend changes inhis traditional environment. It was inthis intellectual atmosphere that Tyk-ociner demonstrated his dream of aquarter century, the recording of soundelectrically on the same film carryingmotion pictures.

Tykociner's device was built aroundthe principle of producing sound bypassing a ray of light through a soundtrack of the film into a special light-sensitive tube converting it into a

fluctuating electric current whichcould drive a telephone receiver orspeaker. Its outstanding feature was therecording of the sound on film photo-graphically, instead of the less efficientmechanical method of making recordings.

Sadly, his work with sound -on -filmcame almost a decade too soon. One ofthe motion picture leaders of that eradeclared that the inventor's sound pic-tures were not practical. He went on toexplain that movies were an illusion ofsound and that if one were to combinethe two illusions simultaneously it wouldproduce a trauma greater than thehuman mind could bear. "The publicwon't accept it," he finalized. So JosephTykociner never profited from hissound -on -film invention the credit forwhich some years later went to othermen.

Tykociner's historic demonstrationof the first sound -on -film movies wasmade the evening of June 9, 1922, at ameeting of the Urbana (Illinois) Sectionof the American Institute of ElectricalEngineers which was held at the Uni-versity of Illinois. The demonstrationincluded a violin player, Mrs. Tykociner,

(Continued on page 16)

14 ELECTRONICS DIGEST for July/August 1972

Photo Courtesy University of Illinois

Joseph Tykocinski TykocinerOctober 5, 1877 - June 12, 1969

Electrical Engineer, Inventor, Educator

ELECTRONICS DIGEST for July/August 1972 15

Photo Courtesy Umversitv

JOSEPH TYKOCINER(Continued from page 14)

ImoiS

This old photograph shows Joseph Tykociner at work in his laboratory at the University of Illinoisat Urbana. He produced a variable -density sound track beside the picture images on the film, theprinciple that is used in motion pictures today. The inventor's wife was the first woman to "star" intalking pictures. With a small bell in her hand, she said, "I will ring the bell." The action plus soundamazed spectators.

who rang a hand bell, and ProfessorEllery B. Paine, then head of theUniversity's electrical engineering de-partment, who recited Lincoln's famousGettysburg Address. It was the crowningachievement of Tykociner, who hadcome to the faculty in 1921 after abrilliant career in Europe in the newfield of wireless communications.

On July 30, 1922, the New YorkWorld devoted a half -page to Tykociner'sfuturistic invention. lie forecast a revolu-tion in the movies. "Many noted plays,comedies, and farces that are not nowadapted to the screen, because of thewit, humor of the dialogue, and person-ality of the actors, may be revived andfind new favor," he predicted. "1 have

great hopes that it will cause a revivalof the masterpieces of dramatic art," hesaid. Today, we know just how accuratewas the prediction of this great man ofvision . . . who saw beyond thehorizon a world several decades away.

Tykociner, who conceived the ideaof sound -on -film recording during avoyage from Antwerp to America in1896, was graduated from Higher Tech-nical Institute at Coethen in 1901, andstudied in Berlin and Goetlingen, Ger-many. He joined the Marconi WirelessTelegraph Company in England as ajunior engineer. Two years later hejoined the staff of the TelefunkenCompany in Berlin as a research engineer.In 1904, Tykociner was offered a re-sponsible position in Russia, and duringthe ensuing fourteen years made theRussian navy the first fleet completelyequipped with wireless. After World

War I when Poland was reborn, Tyko-ciner set up the nation's first wirelesscommunications system.

In 1920, Tykociner came to Americato stay. After a year's work at theAbstinghouse Electric and ManufacturingCompany's research laboratory, he ac-cepted a position with the experimentstation of the University of Illinois. Atthe U. of I. he pioneered in both radioand other electronic fields.

In 1929, he became a professor in theGraduate College. He retired with therank of professor emeritus in 1949. Hisscientific investigations included, besidessound -on -film motion pictures, high -frequency measurements, dielectrics,piezoelectricity, photo -electric tubes, andmicrowaves. He was a fellow of theAmerican Physical Society and theAmerican Society for the Advancement

(Continued on next page)


FROM AN ALBUM (Continued from preceding page)

Licen.red ',fader Armstrong V, S. Patent No. 1.114149.MacMillan Listens to Honoluluand NewZealand "Tunes In" CaliforniaUsingFrom a little ice -bound

Model 3R Thenew Zenith 3Rschooner - eleven degrees fromthe North Pole-comes thismessage:

"Am very thankful that Arctic Ex-ploring Ship Bowcoin is equippedwith complete Zenita radio apparatus.Here at top of world, in darkness ofgreat Arctic night, we have alreadylistened to stations practically all overUnited States, from Europe, and evenfrom far away Honolulu. Zenith hasunited the ends of the earth."

-"MacMillan"Again, from far-off New

Zealand comes a.report of radioreception even more startling:

Long -Distance Radio

-It may interest you to know that the writer last evening landedKGO, Oakland, Czlifornia, between 6:45 and 7:30 P. M. Heard hiscall four 07 five tines distinctly, and jazz music. The music wasnot as clear as the voice, but one could pick up the tune all right.As San Francisco is 6,300 miles from New Plymouth, and onlyone tube was uses, we think this is a very fair performance."

-(signed) H. Charles Collier.

"Long - Distance"Receiver -Amplifier combines a speci-zIly designed distortionless three -stageamplifier with the new and differentZenith three -circuit regenerative tuner.

Fine vernier adjustments - inconnection with the unique Zenithzperiodic or non -resonant "selector"primary circuit - make possible ex-treme selectivity.

The new Zenith 3R has broken allrecords, even those set by its famouspredecessors of the Zenith line. Underfavorable conditions, satisfactory re-ception over distances of '2,000 to

aius oaar, rs atan a,c.e.m-plished in full volume, using anyardinaryloud-speaker. The Model 3Ris compact, graceful in

line, and built in a highly finished mahogany cabinet..... $ 1 60

Model 4R The new Zenith 4R "Long -Distance" Receiver -Amplifier comprises a complete three -circuit

regenerative receiver of the feed -back type. It employs the newZenith regenerative circuit in combination with an audion detectorand three -stage audio -frequency amplifier, all in one cabinet.

Because of the unique Zenith "selector." unusual selectivity isThe sets used by Captain MacMillan and Mr. Collier accomplished without complication of adjustment.are earlier motels-since improved by the addition of The Zenith 4R may be connected directly to any loud -speakera third stage of audio frequency. These new models, withoet the use of other amplification for full phonograph volume.described at tae right, represent an achievement in and reception may be accomplished over distances ofmore than 2.000 miles $85radio cor structi 3n not duplicated in any other set on the

market. A demonstration will convince you.Write today for full particulars and name of nearest I ZENITH RADIO CORPORATION,

dealer. Dept. I -0 328 South Michigan Avenue, Chicago, IllinoisGeitlemen :

Please send me illustrated literature on Zenith Haiti.

Zenith Radio Corporation Name ..

McCORMICK BUILDING, CHICAGO I Address..

Courtesy Zenith Radio Corporation

This is an old Zenith radio advertisement which ran in several publications in 1924, nearly fvedecades ago. It was an exciting era of long-distance wireless communication and Arctic exploration.Note the line under the radio: Licensed under Armstrong U. S. Patent. That was radio pioneer EdwinHoward Armstrong, imentor of the regenerative feed -hack principle of amplification (ElectronicsDigest, January! February 1971).

ELECTRONICS DIGEST' for July/August 197221

History of the Vacuum TubeSome of the more important historical types of gas tubes

are discussed in this article. It serves as a usefulfoundation for treatment of other basic electron tubes

We have noted that the earliest vac-uum tubes were "soft"; that is, thesetubes contained sufficient residual gasso that their characteristics were dom-inated by ionic conduction. Actually,there is no perfect vacuum condition intubes, although "hard" tubes were evac-uated to so great an extent that ionicconduction could be disregarded forpractical purposes. At about the turn ofthe century, it was known that certaintypes of "soft" tubes operated as recti-fiers. The groundwork had been laid in1850 by Geissler, who discovered thatcolored lights could be produced bymeans of a high -voltage discharge througha tube containing gas at a low pressure.

Cooper Hewitt Mercury -Arc Rectifier

were extensively developed by PeterCooper Hewitt, including the CooperHewitt mercury-vapor lamp (Figs. 1 and2). Iron electrodes are located at a andb. Electrode b contacts a small pool ofmercury. A metallic coating d is placedaround the mercury pool, to providecapacitor action for easy starting. How-ever, this type of tube requires a highstarting voltage, usually provided by aninduction coil or step-up transformer.The starting voltage was applied mo-mentarily between a and b. Althoughseveral thousand volts were required tofire the tube, the arc drop fell to

Fig. .1 A Cooper Hewitt mercury-vapor lamp.

Part IV

by Robert G. Middleton

Fig. 3 A Cooper Hewitt mercury -arc rectifiertube.

Auto -Transformer

3

C

T,

Fig. 4 Plan of the Cooper Hewitt mercury -arcrectifier tube. (Continued on next page)

approximately 50 volts thereafter.Discovery of the fact that the mer-

cury-vapor lamp operated as a rectifierwas based on the observation that opera-tion was possible only on dc, with themercury pool employed as the negativeelectrode. Later, the mercury-vapor tubewas operated on ac by means of acircuit expedient. A large inductor wasconnected in series with the tube. Inturn, the flywheel action of the inductorsustained current flow through the tubeduring the inoperative half cycle, so thatthe arc was not extinguished duringthis period. Because the lamp developedpeak output on alternate half cycles, itexhibited an objectionable stroboscopiceffect.

Hewitt was intrigued by the rectifieraction of the mercury-vapor lamp, andsoon developed the mercury -arc rectifiertube (Figs. 3 and 4). This tube was ex-tensively used to change ac to pulsatingdc in most applications which demandedsubstantial current and good efficiency.Operating voltage is applied by the trans-former to the iron electrodes. Themercury pool is connected through loadR to a pair of inductors and thence tothe iron electrodes. An auxiliary startingelectrode is also connected via resistorr to one of the iron electrodes.

To start the mercury -arc rectifier tube,the mounting is momentarily tilted orturned clockwise, so that the mercurypool contacts the starting electrode. Inturn, mercury is vaporized and the tubestarts operation. The mercury pool servesas the cathode, and electrons flow onalternate half cycles into one or theother of the iron anodes. Inductors L

O.SLQiir and L I are used for their flywheel effect.Otherwise, the rectifier tube would be-come extinguished or deionized when

C-441125=MIIIMIIMEMea'°Fig. 2 Construction of the Cooper Hewitt mercury-vapor lamp.


j

Fig. 5 ,4 filamentary type of mercury-vaporlamp.

TUNGSTENELECTRODES

MEiCURYDRJP

TUNGSTENSPIRAL

Fig. 6 Plan of a filameuary mercury-vaporlamp.

Fig. 7 A hot -cathode mercury-vapor rectifiertube.

HISTORY OF THE VACUUM TUBE(Continued from preceding page)

the current pea changes from one anodeto the other. A mercury-vapor tuberadiates a bright purple light.

Hot -Cathode Merciry-Vapor TubesAlthough the Cooper Hewitt tube

operates with an Intensely hot spoton the surface of the mercury pool, it isfundamentally a coil -cathode design inthat no filament of heater is providedfor electron emission. In contrast, thereis the hot -cathode (incandescent fila-ment) mercury-vapor lamp (Figs. 5 and6). When current flows through thefilament, the vapor pressure of themercury rises, and tie mercury vapor isionized by electron emission from the

filament. Thereupon, a mercury -arc dis-charge takes place between the tungstenelectrodes. This arrangement is oftenused as a source of ultraviolet radiation.

A mercury -arc discharge is easilystarted (and sustained) by electron emis-sion from a hot cathode, a featureexploited during the 1930's by rectifiertube engineers. One example is the hot -cathode mercury-vapor rectifier tube(Fig. 7). It employs a coated type offilament, which must be operated forat least 15 seconds before anode voltageis applied. Thereupon, the mercury vaporionizes and radiates a purple glow. Thetube drop is only 15 volts when 7,000volts are applied at 0.25 ampere currentdemand. Thus, the tube operates athigh efficiency.

A cathode in a mercury-vapor tubeemits electrons, and also heats thesurrounding space to vaporize the mer-cury.Therefore, specialized cathode con-structions were found necessary (Fig. 8).Heat from the inner turns of the spiralfilament is absorbed by the outer turns.Thermal radiation from the outer sur-face is reduced by means of a polishedshield surrounding the filament. Theplate, or anode, is a metal cup fittingover the top end of the cathode. Toavoid tube damage in operation, thecathode must be able to emit moreelectrons than are demanded at peakanode current flow. Thus, a mercury-vapor tube has no advantage over ahigh -vacuum tube in this regard; itsadvantage is its high efficiency, due tothe low tube drop.

Argon Gas Rectifier TubesAnother classical type of hot -cathode

gas tube utilizes argon, and was calleda Tungar or Rectigon tube. One varietyof tube contained a mixture of argonand mercury vapor. Mercury-vapor tubesof all types were termed phanotrons.Typical phanotrons are the Tungar bulbs(Figs. 9 and 10). A spiral tungstenfilament was employed, with a graphiteanode. The gas pressure was approxi-mately 5 centimeters of mercury. Toobtain ample electron emission, thetungsten filament was operated at amuch higher temperature than that in ahigh -vacuum tube. Because of the argongas, the tungsten was inhibited fromexcessive evaporation, and the tube wasfairly long-lived.

Thyratron TubesA thyratron tube is basically a three -

electrode gas tube or phanotron. Thatis, a thyratron contains a control grid inaddition to the cathode and anode


r.

MERCURY-VAPOR TUBES WITH HEATER DE TAILS

HOT -CATHODE EMIT TING STRUCTURES

Fig. 8 Hot -cathode construction for mercury-vapor rectifier tubes.

Fig. 9 Representative Tungar bulbs.


H riGH ShG

TRIODE SHIELD GRIDTHYRATRON THYRATRON

Fig. 10 Plan of a Tungar rectifier bulb. Fig. 12 Internal construction of triode andtetrode thyratrons.

Fig. 1I Appearance of a small thyratron.


(Figs. 11 through 13). The control gridin a thyratron does not have an opera-tional function at all times, as in a

high -vacuum tube. Instead, a thyratrongrid can only inhibit anode currentflow (ionization) up to a certain criticalgrid voltage. Thereupon, the tube "fires"and the grid loses control. Anode cur-rent can then be stopped only bybringing the anode voltage to zero.Then, the grid resumes control.

Note in Fig. 12 that the grid in athyratron is designed differently from agrid in a high -vacuum tube. A thyratrongrid shields the cathode both from theanode and from the walls of the glassenvelope. Thereby, the effect of strayfields is minimized and operation isstabilized. In typical thyratron grid con-structions (Fig. 14), control action takesplace through a hole, pattern of holes, orscreening. A double -grid or tetrode typeof thyratron provides shielding for thecontrol grid, in addition to the cathodeand anode. In turn, maximum operatingstability is realized. This type of tube

Fig. 13 A larger type of thyratron.

was extensively developed during the1940's.

Neon Gas TubesMany types of gas tubes containing

neon or mixtures of neon and othergases have been developed. It was notedpreviously that work in this field wasstarted by Geissler in 1850. There arevarious ornamental forms of Geisslertubes (Fig. 15). Present-day tubes usedin so-called neon signs are a direct out-growth of this line of development.During the 1930's neon tubes wereutilized in television receivers (Fig. 16).These consisted of a cold -cathode typeof gas diode, with a cathode 1 1/2 inchessquare, and a wire electrode serving asthe anode. The tube contained neon gasat low pressure, and the cathode surfaceglowed a reddish -orange when approxi-mately 75 volts were applied betweenthe electrodes. A brighter glow wasproduced by higher operating voltages.

In this era, television pictures werereproduced on a "screen" 1 1/2 inchessquare, but a magnifying glass was oftenprovided to increase the apparent size ofthe image. The image was developed bymeans of a scanning disk (Fig. 17). Sincea scanning disk was limited in thenumber of scanning lines which could be


Fig. 14 Conventional thyratron grid con-structions.

DISCHARGE OCCURS THROUGHTUBE WHEN AIR IS REMOVED

!=i11111t=

INDUCTIONCOI L

SPARK TAKES SHORTI AIR GAP

A B

-r

Fig. 15 Geissler tube arrangement, and var-ious ornamental forms.


crcr

HISTORY OF THE VACUUM TUBE(Continued from precedtrg page)

employed, the reproduced images werenecessarily quite crude. To anticipatesubsequent discussion, noon tubes wereeventually supplanted by cathode-raytubes in order to provide large and well -detailed images.

There are many other forms of neonbulbs (Figs. 18 and 19). One of theirimportant characteristic* is the com-parative constancy of voltage drop be-tween electrodes as the current flowchanges. The interval from A to B iscalled the dark -current region. Break-down occurs at B. Little voltage -dropvariation takes place from C to D; thisis the normal operating interval. Arcbreakdown ultimately oxurs at E, ac-companied by a very large decrease in

------

A --,C -- -7

-....,B

/...

VOLTAGE

Fig. 19 Voltage -current characteristic of aneon tube.

voltage drop, increase in current, andoften destruction of the tube. Theconstancy of tube drop provided overits operating interval makes the deviceuseful as a voltage regulator.

However, whenever :.ubstantial cur-rent must be accommodated and opti-mum regulating characteristics are de-sired, larger gas diodes are utilized (Figs.20 and 21). These were developed duringthe 1930's. Various inert gases areemployed in voltage--egulator tubes,other than neon gas. Note that in thebasic voltage -regulator circuit arrange -

ANTENNANEON LAMP'

SHORT-WAVERECEIVER ANDAMPLIFIER

Fig. 16 A neon tube used M a 1930 -vintagetelevision receiver.

Fig. 20 A voltage -regulator tube.

UNREGULATEDDC

PLATE

COLDCATHODE

LENS

MOTO

SCANNINGDISC

VIEWER

Fig. 17 Principle of the scanning -disk typeof TV receiver.

Fig. 18 Some varieties of neon bulbs.

Fig. 22 A strobotron tube.

Fig. 21 Flan of a voltage -regulator tube and basicvoltage -regulator circuit.

ment a probe is mounted on the cathodeand extends into the vicinity of theanode. This structure provides an inten-sified electrostatic field which facilitatesthe onset of ionization and therebyincreases :he dynamic range of the tube.

Strobotron TubeAlthough a neon bulb is a strobo-

scopic light source, it does not have ahigh-intersity output. Therefore, a spec-ialized glow -tube light source was de-veloped in the 1930's for use in strobeapplications, known as the strobotron

ANODE-CATHODE

PROBE

G LASS

tube (Figs. 22 and 23). The strobotrontube was designed to maximize thelight output from the neon gas content.The cathode is cesium coated, and thetwo grids are used to start ionization atthe firing voltage. As soon as the tubeionizes, the grids lose control, andcurrent flows until the anode is broughtto lero potential. Although the strobo-tron is basically a cold -cathode tube, itis comparable to a hot -cathode thyratronafter ionization starts.


ELECTRONICS DIGEST foi July/August 1972 25

ANODE

OUTER GRID(GRAPHITE RING)

INNER GRID(NICKEL)

CERAMIC SPACER

CATHODE(CESIUM COATED) Fig. 24 A small T -R tube.

Fig. 23 Structure of the strobotron tube.

TO TRANSMITTER


T -R TubesDuring the 1940's various other forms

of gas tubes were developed. One im-portant type was called the T -R (trans-mit -receive) tube (Fig. 24). Used inradar systems, it is basically a spark -gaptwo -electrode arrangement in water vaporat a pressure of 1 millimeter of mercury.A simple gap at atmospheric pressurehas a resistance during conduction of30 to 50 ohms. The time for deioni-

-r nrcirg-r-r--7-r zz"---"r

CAVITY TUNING PLUGSMOUNTED ON EACH SIDEOF UNIT

GLASS ENVELOPE

INPUT COUPLINGLOOP

SPARK GAP

\RESONANTCAVITY

ESONANTCAVITY \

zation is about 10 microseconds. On theother hand, a T -R tube may have arecovery time of 3 microseconds, with aresistance of only a few ohms duringconduction. A water -vapor type of T -Rtube has a recovery time of 0.5 micro-second.

T -R tubes are usually designed to fitinto and to be a part of a resonantcavity (Fig. 25). To facilitate ionizationat a low signalvoltage, another electrode,called a keep -alive, is often included.This electrode has a potential of about-1,000 volts with respect to the maingap. A low discharge is maintained bythe keep -alive and one electrode of themain gap. Thereby, a small signal voltageapplied to the main gap easily triggersthe T -R tube into conduction.

ConclusionSome of the more important histor-

ical types of gas tubes have been dis-cussed. However, it should not be sup-posed that other than a preliminarysampling has been presented. The datawhich have been provided serve as auseful foundation for treatment of otherbasic electron tubes, such as photo -tubes, image dissectors, iconoscopes,image orthicons, kinescopes, and special-ized tubes utilized in radiation tech-nology.

4SUPPORTING STUB

OUTPUTCOUPLINGLOOP

T JUNCTION

T -R SWITCH TUBETYPE 721A

KEEP -ALIVEVOLTAGE-1,000V

COAXIAL CABLETO CRYSTALMIXER

TO ANTENNA

Fig. 25 A T -R tube arrangement.


Prize -Winning Crystal Radio of the 1920s

This simple, easy to construct, crystal radio receiver was abig hit in the early 1922s. It was billed in advertisements as

"the simplest radio outfit made - yet as practicalas the most expensive"

In the early 1920's, Hugo Gernsback,editor and publisher of "Science andInvention" and "Radic News" maga-zines, offered a first prize of $100 ingold to the reader who could constructthe simplest practical "radiophone re-ceiver" that would give good results.

Out of about 800 contestants, theeditorial staff of "Science and Invention"awarded the first prize to young JamesLeo McLaughlin of New York City for asimple crystal radio he built in about ahalf hour from easily -obtainable mater-ials; at a cost (at that time) of about400 - not including the earphone andantenna, and which worked as well asmany crystal radios on the market atthat time. Instructions for building Mc-Laughlin's radio were published in"Science and Invention," sometime laterin "Literary Digest," and finally ap-peared in the book "Practical Radio"by Henry Smith Williams (1922). Radio -gem Corporation of New York City putMcLaughlin's simple radio on the marketin kit form, as shown in the advertise-ment from "Radio News."

Construction DetailsAs shown in the illustrations, the

simple radio consists of a pint-size paperice cream container about 3W' in dia-meter; 13 small and 2 large paperfasteners; 3 small paper clips; a coil ofNo. 26 enameled copper wire; a com-mon pin; and a piece of galena crystal.Pictorial details of construction areshown in Figs. 1, 2, and 3, and are easyto follow.

To make the "switch points" forthe coil, take the container and punchnine holes in it al out 1" down from thetop and about 1/2" apart, using a smallnail or an ice pick Into each hole push asmall paper fastener. Using pen and ink,number each fastener from right to leftfrom 1 to 9. Alongside hole No. 1

push two small paper fasteners with asmall paper clip underneath, and mark itGND for the ground connection.

1/2" down from GND punch a smallhole for the starting point of the coil,

By Arthur Trauffer

which is wound with No. 26 enameledcopper wire. Scrape the enamel off theend of the wire, push it through thehole, and wrap it around one of thepaper fasteners (GND) on the inside ofthe container. Pull the wire tight andstart winding the coil. The total num-ber of turns on the coil is about 80, anda tap is taken off at each of the followingturns: 15th, 23rd, 31st, 39th, 47th, 55th,63rd, 71st and 80th. In other words,the 15th turn is contact No. 1, and the

remaining eight taps are made at every8th turn. Be sure the enamel is scrapedoff clean before wrapping the wirearound the paper fasteners on the insideof the container.

Figures 1, 2 & 3 show how to makethe switch lever from a large paperfastener which slides over the contacts.Push the ends of the fastener through theside of the cover, close to the lid. Bendone end down flush with the side and

(Continued on next page

Photo by Art TraufferFig. 1 Again, Arthur Trauffer, of Council Bluffs, Iowa, demonstrates his ingenuity in roundingup parts to build a realistic replica of an early -day crystal radio receiver. These are greatprojects for a home or school museum. Not ordy that, they demonstrate principles ofelectronics as applied in the embryonic stage of radio.


Switch

Fig. 2

Cot whisKer-4 -Pin_-Crystal

PRIZE-WINNING CRYSTAL RADIO(Continued from preceding page)

push the other end through the top andbend over. Place the cover on the con-tainer and bend the fastener so it ridesover the contacts easily when the cover isturned, being sure it touches each ofthem. Cut off the surplus end.

The other large fastener is pushedthrough the lid opposite the switch andis bent, as shown in the illustrations, soit holds the crystal. The catwhisker forthe crystal is made from a short lengthof No. 24 wire and a common pin andfastened as shown in the illustrations.

Figure 3 shows the simple hookup.The earphone should be high -imped-

ance magnetic, and the more sensitivethe better. Crystal earphones can alsobe used, since they are high -impedance.

Use an antenna from 25 to 100 feetlong, and a cold water pipe ground.

Figure 1 shows the replica built bythe writer.

It goes without saying that thiscrystal radio was designed and used inthe early days of broadcasting whenthere were fewer stations and they wereoperating on lower power, so do not besurprised if you hear several stations atthe same time when tuning this set. Thenearest and most powerful stations willof course be heard the loudest.

RADIOGEMThe Dollar

Radio Receiving SetThe Simplest Radio Outfit Made

-Yet as Practical as the MostExpensive!

You need know absolutely nothing about wire-less to operate and enjoy the RADIOGEM. Itis so sturdy, so simply constructed that it issmall wonder radio engineers who have testedit have pronounced the RADIOGEM a brilliantachievement. The RADIOGEM is a crystalradio receiving set for everyone at a price any-one can afford.

Why The RADIOGEM Can BeSold For Only $1

Here's the secret: The RADIOGEM Construc-tion eliminates all unnecessary trimmings, cab-inets and the like, which do not play any partin the operation of a set. You receive theRADIOGEM unassembled, together with aclearly written instruction ,book, which showsyou how to quickly and easily construct the set,using only your hands and a scissor. The out-fit comprises all the necessary wire, contactpoints, detector mineral, tube on which to windthe coil, etc., etc. The instruction book ex-plains simply and completely the principles ofradio and its graphic illustrations make the as-sembling of the RADIOGEM real fun. Re-member the RADIOGEM is a proven, practicalradio receiving set and will do anything themost expensive crystal set will do.

The RADIOGEM is the PrizeWinner of the Age

Out of hundreds of radio models submitted re-cently in a great nation-wide contest, radio en-gineers, the judges, unanimously chose theRADIOGEM as the winner-the simplest radio -receiving set made! And the RADIOGEMcosts you nothing to operate; no form of localelectricity is required.

Sent Postage Prepaid on receipt of $1-stamps, money -order or check.

Order Your Radiogem To-day-or send for Free Descriptive

Circular

DEALERSThe RADIOGEM is the wonder itemof the radio age. It is storming thecountry, for the RADIOGEM'S price isso low everyone is able to buy one.Write immediately for full particularsbefore that shop across the street beatsyou to it.

?he RADIOGEMCORPORATION

66-R-WEST BROADWAYNEW YORK CITY

Hear the programs of the BroadcastingStations on the RADIOGEM

withoutPHONE orAERIAL

(Patent Pending)

What They Say About RADIOGEMI am enclosing herewith $1.00 to pay fnr the Radio -...COI. 1 had it carefully wound by our wirelessoperator nd find that It winks beautitully-tallyas seed as any crystal set we knew ef.

Badlogem received. uhleh we assembled and wereway much astonished at results obtained and theclearness and volume of tone produced.

The greatest distances I heard on one of your setslanu !sites. liming heard Win' al Sehenoctehh

N. Y. I think wur set is the best I have ever soldat any price.tin avail 100 feet long and 20 high one of nip

has heard WOC and Willi, BSI), W\11on one of )our sets using a Peerless headiet.

Berenith P.O.M.O. amt. $1.00 for another "ItA1.10GEM." The one received is 0.1i. Placedabout 15 ft. of picture cord mule! I !torch and

to a pas meter, and heard the SacramentoBee Sacramento Broadcasting Union much bet-ter than with my large crystalset

Your RAIMOCEXI REvEIVER Is a noisier. I hate11,4 heti OCIN 1.11:littlehilda 111th it muchlouder than with a high-prieed crystal set.

Your two Radiogem sets received last night, andone ties wired up for testing. WOC is about inmiles an ny, and their signals could be heard withheadphones on table. Alter they goat KYW at

alinat 17n miles east was beard. Evel)nord mold he Plainly heard here. WN1C at Mem-phis. Tenn., could also be easily heard and under-stood.We find that this set dues great deal more thanyou claim for It. We took WEAR on our sudion setlast night: this being the Baltimore AmericanBroadcasting station, and then rut In the Rodin -gem and got excellent results. After the Balti-more concert was over, we continued to use theaudion set and about ten o'clock were listening to1VEAF-New York-and a little later we discon-nected the 'ninon set entirely and hooked up theRdiorem, very clearly heaving both piano musicand announcement of name of station and Its loca-tion.You claim a radius of 20 miles over your "Radio -gem" is sometimes a possibility. You should ad-here to the truth. I constructed one for my mother,installed it with an aerial. and she listens not oncein a while, but at her will, to Schenectady. New-ark, New York, or Providence. R. 1., nod her homeis Attleboro, Mass. I can't give your set tee muchpraise. - ---

(Names and Addresses en Request)

This is a copy of an advertisement of the Radiogem Corporation, circa 1922. It uses the magicof early -day radio, the reception of signals through the air, to sell its little receiver, "Thewonder item of the radio age."

PARTS LIST

1 paper ice cream container (about 342"x 31/4").13 paper fasteners (small size).2 paper fasteners (large size).3 paper clips (small size).1/4 lb. No. 26 enameled copper wire (RadioShack).1 galena or silicon crystal (mounted orunmounted).1 common pin.1 (or pair) high -Impedance magnetic ear-

phone [crystal earphones can be used] (RadioShack).Sources for galena or silicon crystals:Modern Radio Labs., 754 Cordone, Reno,Nevada 89502 (all kinds of mounted or un-mounted crystals. [Present prices not knownto this writer).]Burstein-Applebee, 3199 Mercier Street, KansasCity, Missouri 64111. No. 12A1401 galenacrystal 25g.


PICTORIAL HISTORY OF ELECTRONICS

Early -Day Radio Sets

Commercial radio began fifty-one years ago this November...when radiostation KDKA went on the air ii Pittsburgh, Pennsylvania-the year was1920. The photographs on this page show several types of radio setsfrom the collection of West Vi-ginia University's Department of Physics

that tuned in programs during radio's "golden age."

The first known radio program in the U.S. wasbroadcast by R.A. Fessenden from his experimentalstation at Brant Rock, Mass., on Christmas Eve, 1906.Two musical selections, the reading of a poem, and ashort talk apparently constituted the program, which washeard by ship wireless operators within a radius ofseveral hundred miles of Brant Rock. In the experimenta water-cooled microphone was used to modulate anAlexanderson alternator and 1 kw. of power was radiatedat the frequency of 50 kc.

Photo West Virginia University

This is the triode tube of a De Forest Audion. Thisinduction set was built about 1907, and was powered bybatteries. The set required use of headphones. The triode,which enabled early experimenters to control a largecurrent with a small signal, was invented by Dr. Lee DeForest. It consists of a bulb with a plate, a grid, and afilament. The entire development of modern electronicsis based on the triode. Ownership of its patent wasfought over in the courts for many years. The patentoriginally was granted to De Forest in 1908, and, after2,863 court cases, it was reaffirmed by the U. S. SupremeCourt in the early 1920's. The final decision, again inDe Forest's favor, was made in the 1930's. The label onthe bulb says, "This bulb is licensed for experimentalpurposes only."

Radio station KDKA at the plant of the WestinghouseElectric and Manufacturing company in East Pittsburgh,Pa., began broadcasting regularly scheduled programs,operating on 833 kc. with 50 w. of power. KDKA first wenton the air in the evening of Nov. 2, 1920, with a broadcastof the returns of the Harding -Cox presidential election.This occasion was generally conceded as marking thebeginning of commercial broadcasting in its modern form.The success of the KDKA motivated others to installsimilar stations.

(Continued on page 18)

Okey M. Cogar, research technician in West VirginiaUniversity's Department of Physics, tunes one of theoldest sets in the department's collection. This battery -powered model was made by the Signal Radio Companyof Menominee, Mich., in about 1907 and was known as aloose -coupled receirer. Each listener had to have a set ofheadphones. Tuning these sets was a tedious affair andrequired the continued attention of the operator.



Bell Telephone Labs

Lloyd EspenshedBorn 1889

Electrical Engineer -Inventor,Wire and Radio Communications Pioneer


T.M

BIOGRAPHICAL SKETCHES OF GREAT MEN IN ELECTRONICS

Lloyd EspenshiedBorn 1889

Electrical Engineer -Inventor,Wire and Radio Communications Pioneer

By William M. Palmer

America, a relative of all the nations of the earth, hasmade many noteworthy contributions toward a better wayof life for mankind - many of these contributions havecome from our men of science.

One of the tragic frailties of human nature is thetendency to forget, out of the complacency of an affluentlife, the accomplishments of these men as environmental"problem solvers." As we go about our daily lives, enjoyingthe many conveniences made possible by modern technol-ogy, we often take for granted the countless hours ofresearch which preceded the great. inventions that liftedour country, the United States, to the highest standard ofliving in man's history . . . in less than 200 years. How,otherwise, could our country have given assistance - food,money, and equipment - to more needy people of theworld than any nation since man's beginning in the dimpast?

One of the many brilliant American scientists was apioneer in the development of both wire and radiocommunications. He was co -inventor, with Herman A.Affel, of the system for using a coaxial conductor (coaxialcable) as a wide -band, long-distance, transmitting medium.The application for the patent mentioned its possible usefor television transmission - the forerunner of today'stelevision coaxial cable system which makes possiblenation-wide network television programs.

In 1915, teams of engineers from the old West StreetLaboratories of the American Telephone & TelegraphCompany, under the direction of John J. Carty, beganestablishing radiophone test sites at a number of pointsalong the Atlantic seaboard. In October of the same year,from a site leased from the U.S. Navy at Arlington, Virginia,speech was successfully transmitted and simultaneouslyreceived in both Paris, France, and Honolulu, Hawaii. Hewas the receiving engineer in Honolulu during the historictest.

It was the same year that another "first" took place,when the transcontinental telephone line was opened withconversations between President Woodrow Wilson at Wash-ington, D. C., Alexander Graham Bell at New York City,Thomas A. Watson at San Francisco, California, and thefounder and first president of AT&T, Theodore N. Vail, at

Jekyll Island, just off the coast of Georgia.Another important invention by the subject of this

biographical sketch was the radio altimeter, which demon-strated its practicality as an air navigation instrument in1938.

In addition to these noteworthy accomplishments, hehelped to develop single sideband (SSB) which has foundwide use in modern communications - both commercialand amateur radio. He holds more than 130 patents in thefield of electricity/electronics.

In spite of his brilliant work in science, few Americansof today's generation would recognize the name of thisdistinguished engineer -inventor, Lloyd Espenshied.

Mr. Espenshied was born in St. Louis, Missouri, in1889. By age 14, he had already developed a keen interestin amateur radio, which may have influenced his choice ofa career. He attended Manual Training High School inBrooklyn, New York, and later attended the famousPratt Institute, where he received a degree in appliedelectricity in 1909. It was while attending Pratt Institutethat Espenshied worked part-time as a radio operator forthe United Wireless Telegraph Company of America.

Upon graduation from Pratt Institute, Mr. Espenshiedjoined Telefunken Wireless Telegraph Company, as anassistant engineer. After a brief work span there, he joinedthe engineering staff of the American Telephone & Tele-graph Company, and later the world-renowned Bell Tele-phone Laboratories. He retired in 1954.

Many honors have been bestowed upon this distinguishedAmerican. He is a Fellow of the Institute of Electrical andElectronics Engineers, a member of the American Associa-tion for the Advancement of Science, and a member of theAmerican Geographical Society.

Mr. Espenshied was awarded the Medal of Honor of theInstitute of Radio Engineers in 1940, and in 1967 wasco -recipient of the Pioneer Award of the Institute ofElectrical and Electronics Engineer's Aerospace ElectronicsSystems Group.

Yes, we in America owe much to our men of science ...whose research work began in the past, when today wasstill a dream; whose subsequent discoveries have madetomorrow a vision of hope.

ELECTRONICS DIGEST for July/August 197117


Cogar is tuning the loud speaker that was used with theAtwater Kent receiver. Adjusting the tension on thediaphragm changes the pitch of the sound. The idea wasto eliminate some of the "tinniness" of the early receivers.


This Crosley two-step amplifier was made by the CrosleyManufacturing Company of Cincinnati, Ohio, in about1920. It was used with a crystal detector set andheadphones. All of these early sets required very longoutside antennas, some of which were tunable.


FROM AN ALBUM(Continued from page 15)

The Atwater Kent was a household favorite during thelate 1920's and the 1930's. This model was built about1925. Note that earphones had been replaced by a horn -

shaped speaker. The Atwater Kent had lots of batteries -6 -volt storage batteries for the filament, a large dry cellfor the B+ voltage, and several dry cells for the C voltage.


This Grebe Synchrophase Radio Receiver was made byA. H. Grebe and Co. Inc. of Richmond Hill, N. Y., inabout 1928. The fine workmanship exemplified by thismodel is not exceeded in sets made today. Batteries wereused for power. Sets that could use house current didn'tbecome practical until about 1930 because of the greatvariety of power supplies available to home owners indifferent sections of the country.


Documents

Old -TimeRadio · FROM AN ALBUM (Continued from preceding page) MacMillanListensto HonoluluLicen.red ',fader Armstrong V, S. Patent No. 1.114149. and NewZealand "TunesIn" California