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36 RADIDTUBES G BEREACTIATED Bureau of Standards Gives Simple Process for Use of Set Owners. Radio tubes, like some of the older humans, eventually lose their “pep” under the strain of constant work and require a rest or need to be rejuvenated. This rejuvenating proc ess, as applied to vacuum tubes, is not as serious an operation, how- ever, as the one some humans un- dergo in the search for youth. It s known as “reactivation” and is said by the Bureau of Standa radio experts to renew the sensitivit of electron tubes of the thoriated tungsten filament type. Concerning this method of reacti- vation the burean has issued the fol. wing report, so skilled listeners can pep up” their tubes themselves: Electron tubes in radio recelving sets eventually lose their sensitivity. This sometimes progresses to the point where the receiving set op- erates very poorly or not at all, even though the tube filament is not burned out. The user of the set fre- quently confuses this condition with that due to an exhausted B battery. If the tubes are of the thoriated tungsten (X-L) filament type they { can usually be rejuvenated by a sim ple proce: and made to serve as well as new tubes in the receiving set. Two Cannot Be Reactivated. “It happens that most of the tubes now used are of the thoriated tung- sten type, and it therefore becomes of quite general interest for the public to know how to secure the full life of their electron tubes. The WD-11 and WD-12 types of tubes are the only ones extensively used which can- not be reactivated. In these tubes the source of the electrons is a coat- ing of certain oxides on the surface of the filament, and when this has been used up no process can re- new it. “The thoriated tungsten filaments, however, used in most of the various other types of tubes, contain the oxide of thorium throughout the whole mass of the tungsten filament, this oxide having been originally put in incandescent lamps to keep the filaments from being too fragile. The filaments are give a treatment which produces a layer of atoms of thorium on the surface of the tungsten, and this thorium, which is radioactive, emits electrons much more copiously than the tungsten would, After long use, or after burn- ing the filament too brightly, the layer of thorium atoms is evaporated off, and so few electrons are then emitted that the tube does not func- tion properly. Reactivation 1is a process which bolls additional thorium atoms out of the interior of the fungsten filament and for! a new layer of thorium atoms on the sur- face. Process Successful. “The tharfated filament was de neral Electric Co., | oped the methods of re-| S t type. The| found that| is quite suc- elop: which Bureau of Standards the reactivation proc cessful, and frequently makes a won- derful difference in the results obtain- ed with a receiving set. The process is essentfally the operation of the fila- ment for a very brief interval at a Specified high voltage (called “flash ing”), followed by a lower voltage for ! a longer time (called “aging”), all of this with no grid or plate voltage.| The flashing reduces some of the thorium oxide in the wire to thorium the aging forms the re- quired sur The following schedule of these operations is the result of extensive experience of the Radio Corporation of America, and is published here by courtesy of that FLASHING Time. 10 min. 10 min. 10 min; OX and UV 109, & Tx and UV 201-A.. 0X-120 .. “ . me procedures ap- ply for tubes as for the UX tubes of corresponding number. Thus, C and CX-289 correspond to U and 9 and CX-301-A to U and UX-201-A and CX-220 to UX-120. “In carrying out this schedule it is absolutely essentfal to have a volt- meter of a good degree of accuracy and to use a watch. No grid or plate voltages are used. Either alternat. ing or direct current may be used for heating the filaments. Must Need Treatment. “It is important that reactivation not be attempted until the tube user has assured himself that the tubes actually need this treatment; that is, he should make certain that his bat. terfes are not run down and that other parts of the receiving set are in proper order. The schedule above should be followed with great care. The process is useful only for the thoriated tungsten filament type of tubes. “The apparatus necessary for carry- ing out the process is simple. The filament is connected to the neces- sary source of voltage, nothing being connected to the grid and plate. A voltmeter {s connected across the fila- ment terminz If alternating cur- rent is available the source of voltage can be a smail transformer, such as those for running doorbel tric toys. The voltage tap nearest the voltage specified should be select- ed and a rheostat in series with the filament used to adjust to the exact voltage. The voltmeter must be one for alternating current. “If alternating current and a trans- former are not avallable, dry batteries or storage batteries may be used as a source of voltage. A single dry cell when new will furnish approximately 1.5 volts. A rheostat should be con- nected In serfes to give the exact filament terminal voltage as indicated on a direct-current voltmeter. “There are several manufacturing companies that advertise tube reacti- vators at varying prices. Radlo deal- ers are beginning to give tube re- activation service.” Announcer at New “Mike.” The volce of Lambdin Kay, director and announcer at WSB, Atlanta, will be heard this week from WLS, Chi- cago. George Hay, “the Solemn Old Judge” at the Chicago station, has gone to the Texas State fair at Dallas, and left the microphone in charge of the Atlanta announcer, who is en route home following an engagement at the St. Louls Radio Exposition. Transatlantic Tests in 1926, January, 1926, will usher in the trans-Atlantic tests, and already ex- tensive preparations are being made by the broadcast stations listed for participation. The broadcast listener also is fixing up the old set in anticipa- tlon of picking up 2LO and the vari- ous continental stations, who will again attempt to entertain the Yankee radlo fans. . |about the grid condenser,” Smith sug- KSO is assigned to a new station planned by the A. A. Berry Seed Co. #t Clarinda, Iowa. LONG RANGE RADI THE SUNDAY 0 ENTERTAINMENT SUNDAY, OCTOBER 18, 1925 Programs of Distant Stations Scheduled for Eastern Standard Time 9:00—New York: Children's hour: 204 10 7O 11 AM. 10:00—Rossville, N. 10:20—Philadelrhia: Arch Strvet M :30—Atlanta: Axora Sunday school class Cincinnati;"Sunday schcol by Method Jefferson City: Christ 45—Atlantic City’ C) Pittaburgh 10 : Watchtower Orchestra; solos: Bible talk E. Church services .... : 185 ist Book Concern. Philadelphia: Holy Trinity Church services .. 11 AM. TO 11:00—Rossville, N. Y.: Vocal solo Springfield: Trinity Church services Louisville: Broadway_Chrstian Church Schenectady: Grace Ej i2 NOON. 7 Watchtower Orchestrs. New York: West End Presbyterian Church serv ices . ces Episccral Church services New York: Third Church of Christ, Scientist. services Boston “athedral Church of St. Chicag Paul services .. Sermon and services from People’s Church... 12 NOON TO 1 P.M. 00—Cincinnati: Church of the Covenant Chicago: Central Church services . Atlanta: First Preslyterian Church Hot Springs: Central Methodist Chuw Des Moines: University Church Minneapoli 30—Schenectady : Program from Rivoli 170 2 1:00—Chicago: Vocal and instrumental con: hour E Chicago: Uncle ' Walt New York 30—Boston: ‘reads “the 'fun Lexington organ recital Concert program ....... wervices . Plymouth~ Congregational Church e services services . reh services . I WHO LLLweco Theater, WJZ JIWGY P.M. cert; organ: Sunshine nies o childs 2 TO 3 P.M. 00—Philadelphia: New York Chicago _ Davenpcrt 15—Atlantic City: Searide Hotel Trio Chicago: Shepheid time: Aerial Girl 2:30—Philadelphia: _Bethany Sunday New Ycrk: Radio forum .. New York: Queens Count; Arcadia_Concert Qrcher Sunday hymn eing’'; stra church Concerts and studio recital ... mer Little Symphony ~Orchestra 3 TO 4 P.M. 00—Chicago: Radio program New York: Ci Chicago: Raula York: Warner's Cleveland:~ Concert 3:45—Cincinnati: Address of Y. M. C. A. reporter: missionary ading <olos sran Gloria Trumpetel program soloa . m in” Bedy, s from 4 TO 5 PM. 00—New York: Reiner's hour: talks: solos New York: St. George's' Episcopal ¢ icago: Concert. vocal and Pitigburgh: Organ r Shadyside vesper services Toves d_inetruiient tal 15—Atlantic. City _James' Epl 4:30—Philadelphia: ¥ 5 T0 6 choir . hurch se; instrumental Presbytert al *program s; quartet’ P.M. :00—New York: Tuillght concert, New York Quintet ew York iladelnhia Roseland Dance ‘Orchestra. Pias church services heus Male Quartet 0 concert . : House of Hope Preabyt: Christ Church Evensong 6TO7 10—Minneapolis 30—TLouisville Concert progrem .. Roemer's’ Homers . fladelphia: Pennsylv as City: Sunday Philadelphia: Organ re 6:30—Chicago: Y1 Vi tion Orchestra M. 1a Hofel "Orchestra 45—Boston: " Park Street Congregational Church’ services. 7 TO 8 7:00—XNew_York: Ernie Vail and ring Ensemble as' Hotel Pent Arctic_from the Al fillan. explorcr. WEEL WCAP. ien’s Hotel McAl P.M. pin Orche: man’ Theater Orchestra . % York: Mueical program by Capitol Gang,” WEEL WCAF WWI .. e 7:30—Dallas: Firat Preshyteri Davenport: Church Chicago: Organ recital New York: C Baptist Chureh ¢ o Band t Sl it Hills Chris h services sea Bapt Pittshurgh i 50—A ¢ 8 TO ® . Edward Bowes ‘and the . WJAR, WCAE. WCTS, Little Church in’ the Vale services rvicel P.M. rumental quarter Reminiscences of Club_ servi's: cho program _........ < concert: Hernstein race ‘Episccpal Chasdl galk oo 45—Cincinnati: Chimes cone 9:00—Cincinnati Sermonet: musical progras rth Avenue Presbyterian \ ¥ v “Ludlow,” vioi Chicago: Ralph Wilila el ‘&nd instrumenta) program New York: String Q tet: e ity Rekuide Hotel Tie M.E. Ehirn trvicea solo ity Hote Amnnaador ¢ Rossvifle, Y Choral Zion, IIL.: Mixed and b 2N woloista; trio: reading 15— New Yok Radlo Houss Toise I WEEL Wik WoS! WIAK W rom Coneert ‘Drokram Musical progiam 30—Cincinnal orchest New York: hdn s 10 T0 1 City: Organ recital: soloist, orics Godfrer Tuidiow. ago’ Tribune 1 Hot “Springs: Do T 15—Minneapolis: Weathe 30—Chicago: All-American Dallas: D i Pionee program nssen’s Hofbral Orchestra Davenport: Palmer Little Symphony M. TO 12 _ Phil Baxter and his orchestra Vocal and instrumental recital y rwan recital 00—Hot Springs Cineirnaty :15—Atlantic Ci 40—Chicago: Bac trand Theater o -home hour . s Collegiana .. 2 Report Trio m: solos . Church gerv ot, WIZ an ms and his Rainbo Gardens Orché: vocal solos i s quartets: TW. ra: solos .. LM SATL 1oliniet B%E> R0 Orchestra; MIDNIGHT. 12 MIDNIGHT TO 1 AM. 00—New York: Club Richman entertaine: John Smith and His Radio BY FREDERICK C. RUSSELL. Car _ouwners throughout the world Aav motoring—and have benefited thereby willing that his fellow fans shoul ezperlences, Smith hus’a faculty radio devoiees to follow him in The No. 35—Grid Leak Explained. Smith had been looking over circuit diagrams and was interested to note that {n the majority of them there was provision for the insertion of a GL in the circult just before the grid of the detector tube. It apparently was in serfes with what he had come to rec- ognize as the grid condenser. “I don’t quite understand this,” he said, pointing to the mysterlous little radio unit on one of the dlagrams. “Understanding the function of the GL is simply a matter of going over your first lessons in the activities in a vacuum tube,” I explained, “The GL is the grid leak, and it is very well named.” “Maybe you had better tell me gested. It was the logical step, so T ex- plained the first principles, reminding him of the nature of the radio fre- quencles which were coming in over the aerial and which, after being suit- ably tuned in the tuning apparatus, were being fed to the grid of the de- tector tube. The nature of alternat- ing current, which is radio frequency current, is such that in a group of oscillations the current is built up negatively to maximum, and then drops back to zero, builds up to a makimum positive charge again, only to return to zero before the next group of oscillations commences. “Earlier in your experience as a radio fan you learned that a con- denser was a true reservoir of elec- tricity,” I explained. “Its function in connection with the grid circuit is to provide the applied potentials. Gen- eradly speaking, it assists in getting the radio type of alternating current to the grid of the detector tube in the way it should, first positive and then negative. T Understand,” Smith said. “Now what happens when the grid is posi- tively charged?” Action of Grid. “That's easy when you realize what is happening in the tube when there is nothing coming in at the grid, as is the case when the set isn’t tuned in. There is heat in the tube because the fllament has been lighted. There is a strong charge of positive current on the plate of the tube because the plate is connected to the ‘B’ battery. From the heated filament of the tube electrons are being shot into the space of the tube and they finally reach the plate. Electrons are always negative, you know, and -since unlike electric currents attract each other the elec: trons are attracted to the plate. for. e foliowed John Smith in his dail radio, and i 0w Re has taken v, be, amused ‘and profie by his” ememing 0 it will pay “finding out tAings,” sunday Lrar" cath eer: gxperts know as the norm: a flow of current. Well, now, le’:l us‘:;; what happens when we give the grid a positive charge. First of all it tends to pull more electrons from the fllament and assists them in finding their \Ani\’X :\}(l‘rns. to the plate. As soon as this happe: C1 sty ppens the plate current “Reversing this process, by a negative charge on the '.;J}é‘"’&i find that the electrons are repelled. They can't get over to the plate and so the plate current decreases, Process Alternates. “This process is going on, alter- nately, at an astounding rate, but the grid isn't cleared of electrons at the end of each cycle. Some of the elec- trons which are attracted to the plate when the grid is positively charged :taly anln a:d mc’ream\ its negative otentlal when it is v Ll negatively “If the thing kept up that way," Smith suggested, “the grid would ::)C;n” have too high a negative poten- !'Then what would happen?” “Why, I suppose the electrons wouldn't have a‘fchance to leave the filament.” ““And the plate current would be reduced to zero,” I added. “The tube would be choked. That, in a nutshell, is why you must use a grid leak. This excess negative potential must be drained off. The grid leak is noth- ing more than a resistance connected across the grid condenser terminals. It provides an automatic leak when the maximum charge has accumulated on the grid. Of course, there are dif- ferent kinds of grid leaks and different ways of using them. Going back to the grid condenser you can see now how the condenser serves to lead the incoming radio frequencies to the grid without loss in the grid leal Next Week, No. 35—Economizing on Current. (Copyright by the Ullman Feature Service.) High Prices Hamper U. S. Sales. Unduly high-price charge for Amer- fcan-made radio receiving sets by agents abroad is tending to restrict the sale of these appliances, according to reports from several Department of Commerce representatives. It is sug- gested that American exporters of radio apparatus check up on the sell- ing prices of their products outside the country. e Six out of every ten musie stores in “Because the electrons furnish an electrical path, current starts flowing tqr the filament. That is what radio the United States handle radio_sets along with musical instruments, ) STAR, WASHINGTON, MME. HOMER ON RADIO. Will be Third of Distinguished Artists of WCAP Series. Mme. Louise Homer, whose name has been a symbol of the best in American opera and American home life, will make her radio debut as the distinguished artist on the third of the series of Atwater-Kent radio hours to be broadcast tonight by WCAP and a chain of other statlons stretch- ing from New York to St. Louis. Mme. Homer al will be divided into four the first, several hymns by chubert, Haydn and Bailey; second, an operatic aria; third, a group of three light numbers, number of well known Ruth Emerson will ac- the plano. l.ocalRadioEntertainmenl_ nd fourth, songs. Mis company Mme. Homer Sunday, October 18, 1925. NAA—Naval Radio Station, Kadio, Va. (434.5 Meters). 10:55 a.m. and 10:34 p.m. reports. WCAP—Chesapeake & Potomac Tele- phone Co. (168.5 Meters). 11 a.m.—Service from Foundr Methodist Church. Rev. Frederic Brown Harrls, pastor, will deliver the sermon. 4 p.m.— Service Chapel, Washington ( 0 to 9:15 p.m.—Mu Maj. dward Bowi pitol Family.” from Theater, New York City. { part of the program will direct from the and will consist of music tured artists nd the Capitol Orchestra. The second part program will consist of a special pre: entation by Maj. Bowes of vocal and instrument artist direct from the in_the th o WEAF, WJAR, WCTS wwJ undl ‘Weather t Bethlehem thedral. al program and the the Capitol The first be by of the 9:15 to 10:15 p.m.—"Atwater Kent Radio Hour,” presenting Mme. Louise Homer, from the studio of station Prog: “Xerxe: bert), “Long, Louise m follows (Handel), *S Mermald Long Ago” Homer; arla, (Bailey), “Mon coeur “Samson et . Louise (de Ko ong,"” “How's My Boy?” (Sidney Homer), Mme. Louise Homer; “Little _Orpha rederick Krul), “C Night” (Carl Bohm); < of Song” (Men delssohn), “Battle Hymn of the Re public,” Mme. Loutse Homer Zarly Program Monday. 1 6:45 7.45 a.m.—“Tower Health| Exercises” from Metropolitun Tower, New York City WRC—Radio_Corporation of America (168.5 Meters), silent Early Program M 10 a.m.—Women's hou from WJZ, New York. noon—Organ recit Congregational Church 1 p.m.—Shoreham Hotel Orche. ROCHESTER RADIO CLUB | LAUDED FOR EFFICIENCY Tests During Industrial Exposition Show Rapid and Accurate nday . broadeast from F; Dispatch of Messages. ROCHESTER, N. Y., During the Rochester industrial ex position, held here recently, the Rochester Radio Club received much commendation for the remarkably etficlent message service wh it | ntained free for the of th it of the wo! v and New well as man various points in the United States. were handled dur ing the time of the show. As an illustration of the dispatch with which the messages were handled, one radiogram, rel d by the am teurs, arrived at its Washington, D. C destination 40 minutes before a t gram between the same two poir The best record of all. however, that made by mess to Aust These were delivered in Australia the next morning, by means of relay sta tions of the American lio Rel League. The usual length of time re- quired in ordinary cable usage is from four to five days betwsen the e; coast of the United States and interior oints in_Australi October 17 Acoustics by Brandes means better radio. The mew Pho- Bograph Attachment is truly semarkable. It fits any pho- nograph. Same unitas Type H Speaker. Experts in radio acoustics since 1908 D. ¢, OCTOBER 1 =y To Make Radio Debut MME. LOUISE HOME Famous American opera star, who will sing tonight as the featured artist on the third of the series of Atwater-Kent Radio Hours to be broadcast by WCAP and 12 other stations. President’s Speech on Air. President Coolidge’s addr international convention of the Y A Saturday morning, at 10:30 o'clock, will be broadeast by WRC in conjunction with WJZ New York nd_ WGY in Schen The wonderful new Hafner “Drip Pruf” Hydrometer will save your rugs, furniture and clothing. More—it can be used in close quarters! This patented Hafner Tester has long, flexible hose which is not re- moved from the acid when testing permits reaching into your cabinet under the table or any other inacces- sible place. Bottom of barrel is sealed prevents acid from dripping. G beads on the float prevent stickin and insure accuracy. Colored mark- ings make readingyquick and easy Most good dealers have them —and at $1.00. Why accept less than a Hainer HAFNER MANUFACTUPING CO. 3128 Carroll Ave.. Chicago Distributed by NATIONAL ELEC H. €. ROBER' Control Receiver [ # SUPER-SELECTIVITY § “Through Thermiodyne's ] Master Control is the out- standing achievement of radio. Thermiodyne’s dial is calibrated in wave- lengths, justlike the radio program in your daily paper. Thermiodyne’s Master Control brings in your station instantly—in musical tones and loud speaker volume—free from distortion and in- terference. The nearest authorized dealer is always ready to dem- onstrate the superiority of Thermiodyne. He will explain to you just why you need Thermiodyne’s super-selectiv- ity to get what you want—and hold it!—in the traffic jam of today’s radio channels. Get a demonstration! THERMIODYNE RADIO CORPORATION 1819 Broadway, New York City DEALERS: :c:;]‘i‘n:'frf:; miodyne speak quick for sel franchise in your territory. Get in touch with us at once. Let us hear from you today. Distributor Carroll Electric Co. 714 12th St. N.W. 71727777777 L 7T TT L7777 LT L A7 1T T T T 774 WHOLESALE DISTRIBUTOR Southern Automobile Supply Co. 1519 L St. N.W. Main 3564 1771771777111 11TII 1 TZIET ITITI 177717772771 777 75, GIILLIIITIEIT AT T LIl LI T2 JLI2 2L I T LRSI LIT 1022 ¢ =7 W S S S S M S S S S A S Y iy 4 | the 1925—PART 1. demic year, according to a letter neipal Frank aniel received lay from C. :Conn, dean of Theater Seats Used by Movie Critics : In New York Labeled “Murderers’ Row” | | Dispatch to The Star. W YORK, October 17.—In War- Theater in New York there is i Tow of seats which is well known to the motion-picture critics of New York as “Murderer’s Row." To each s fastened a glistening copper upon which is etched the name of the particular reviewer for whom it is| reserved for occupancy. This inno- vation dates back to the day that the Piccadilly Theater, now Warner's, was thrown open to the public of New York. Shortly after Herman Heller, con- ductor of the Warner's Theater Or- chestra, took over the musical reins he noted that there were no seats in “Murderers’ Row" for the radio edi- tors and their staffs of the metropoli- tan dailies. A few Zgo Mr. Hel-| v not only ordered iameplates for | the radio editors and thefr col . but enlisted the aid of radio engineers | and one of the 1 % turers | of head phones a cBmplete | allation in the auditorium, where the actual adeasts may be heard by the radio critics who visit the theater on v evenin Each seat will be equipped with special individual jack to which th head phones may be attached. When Herman Heller lifts his baton to conduct the overture, for ex-| vote of the facult umple, the microphones in the War- | s has been ner's Theater auditorium will pick up music, which in turn will go through the control hoard, over land wires to Wi , then broadeast from | that station’s antenna and picked up | by receiving set in the theater, tc which will be attached the head | at the radio ities’ seats. novel arrangement will, it is expected, permit an accurate com-| parison between the aural quali' of | each mus 1 f u ans? o rtise. | ment and ctual quality of e broadeast. 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METRO ELECTRIC COMPANY sad e oo S Ty Tho idet Tuoed Htadfo. America W. Hoeke, of Lehigh Univer- wwarded freshr sis of his excellent ccord during the FEATURING ATWATER KENT RADIO ROBINSON’S MUSIC STORE, Ine. | 1306 G_St. “The key to simplified tuning” brings the best out of yr set Ichnwanxaspeakuthxtwfllgiveyoupamzntm ice and stand up under constant usage buy the Saal Soft Speaker. It is made to last a lifetime. The neck is of aluminum. The bell is of genuine Bakelite. There is no wood, no tin, no composition. It has nothing to warp, crack or deteriorate. The reproducing unit is of all-metal construction and cannot be harmed or “blasted” by the . loudest receiver. It maintains its tone with any volume. It combines volume with a velvet tone. It hasno blare,no blast,no metallic ring. It is guaranteed togive you satisfac- tion. Hear it at your dealer’s today. Saal Jr. $20. “Distributing Jobber™ National Electric Supply Co. 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The Deresnadyne is remarkable for its selectivity. In this respect it acknowledges no superior. The Deresna- dyne is remarkable for distance. Operating from Chicago where the intesference is owners have reported the reception of Cal- gg;::mg Los Angeles and Springfield, Mass., in one evening. The dyne is remarkable for volume. During Intemational week, openating from Chicago, it brought in European stations loud and clear over the loud er. DERESNADYNE 11, illustrated sbove, makes available to those who already own battery and speaker equipment the same perform- ance as Deresnadyne I and III, which operate from the light socket. Specially priced at $125—little more than the cost of an ordinary set. D. light sockes. ADYNE IiI—a comblete 3-tuie receiver oterating from the : ndrews Deresnadyne Radio Receiving Set ANDREWS RADIO CORPORATION - 1414 S. WABASH AVENUE . CHICAGO District Office: Borden & Moynelo, 1336 New York Ave. Distributed by Robert C. Rogers Co., 1223 Eye St. N.W.