Evening Star Newspaper, January 15, 1925, Page 41

ANATEUR STATION S RADIDPROBLEN Department of Commerce Has to Keep Enthusiasts Within Proper Bounds. the proportion; s and the 1 with task of . 1s ether « the the air ir s a officials Department perhaps urs of revo- the n in value worth of or on ihe ir with unless he 18 Most ef are value- a vast improve- ht. ordinary user of a radlo fe- set really knows but very lit- wave length other, the ma e gone in for the! of the sets being ! reaching bands which are » does get a set, or so re- | s his set as to tune in on the | trafhi t, then and then appreciate what is really | 8| circuit his home- | THE EVENING_ STAR, WASHINGTON, D. C, THURSDAY, JAWARY 15, - 1925. FIFTEEN MINUTES OF RADIO EACH DAY BY JOSEPH CALCATERRA, Noted Authority on Radio. ot e All Rights Reserved. Reproduction Prohibited. The Fundamentals of Radio G#d Circults. Part 111 8o far we have taken up only the simple grid eircults used in radio and audio frequency amplifier circuits, be- cause these are the simplest of their | kind and are the easiest to under- | stana. By far the most important func- | tioh of the vacuum tube is it use as a detector of radio currents The grid circuit of the detector is practically as simple as thosa of the amplifier circuits. | The eonly difference from the simplest circuit shown in the article | of day. before yesterday Is that a | grid condenser A shunted by a grid| primary coll. In that case, the serial would be connectsd with the grid end side of the cofl and the ground with the filament end of the coil to form what might be termed a con- ductively coupled single-circuit de- tector circuit. In all the circults that we have considered so far no means have been known for tuning the clrcuits or for making it possible to adjust the circuit constants so that it will be possible to tune to different statlons. All that has been shown in each case is a simple coil In most cases without any condenser connected in the circult at all. The capacity in the ocifouits has been there neverthe- less In the distributed capacity of the coll windings and in the inter- electrode capacity existing between the elements of th® tube, in this case i between the grid and the filament The means for tuning the grid oir- cuits will be discussed tomorrow. Caution Saves Tube Blowout. Before changing the battery 6on- nections to a set the tubes should al- vs be removed. The most careful of | radio fans allow short circuits to oc- cur, and even if the connection lasts only an instant, it is usually enough to blow the tubes out, if the B bat- terles are in the circult. e Study of Waves Planned. An exhaustive study of what hap- | pens to radio waves after they léave the broadcasting stations is to be made by the Moore School of Electri- cal Engineering of the University of Pennsylvania. leak resistanca B has been connected into the petween the secon- rid of the tube. 1t s also important in detector wrid vircuits that the grid re- turn be connected with the positive A battery lead of the flament cir- cuit Grid Condeaser Funetfom. The function of the grid condenser is to keep the gtid of the tube at the best operating potnt for detec- tion. In that respeot {t performs | practically the same funotion in keep- ing the tube at its best detector Loperating point as the C battery does /in keeping the amplifier tube at its best amplifying point. The grid leak acts more or less| as a safety valve to keep the tube| from “choking up” due to the rapid {accumulation of negative electrons| | on_the grid. | When too many of them accumu late on the grid, the negative elec- | trons leak off through the grid and back to the fillament circuit, thus re- lieving the grid of the excessive negative charges. You will now see | why the grid return should be con- mected with the positive side of the filament circult. H In electricity, like charges repel and unlike charges attract. If the grid return were connected with the | negative side of the filament circuit, | the negative charges would not flow | back from the grid to the flament| — REMEMBER — The Victor Artists Are On the Air TONIGHT Get a Radio and Listen in ; COMPLETE RADIO SET Covers Everything Needed SCHOOL OF ETIQUETTE WANTED IN REICHSTAG Democrats Inspire Movement When One Member Spurns Visiting Custom. By the Associated Press, BERLIN, January 15.—Democratic members of the Relchstag propose to establish a school of parliamentary etiquette for the benefit of such depu- ties and presiding officials who refuse to observe the ordinary amenities of soclal intercourse. The movement was inspired by the action of Walter Graef, member of the Relchstag and vice president of the Nationalist party, who, after his election, declined to join other mem- bers of the Belchstag in paying the customary visit of courtesy to Prest dent Ebert. The Democrats have in- troduced a motion in the chamber de- manding that Herr Graef be censured for failing to observe the tenets of traditional etiquette. . OFFERS STERILIZING BILL. Woman Doctor Wants Law for Mental Defectives. DENVER, January 15.—A bill to le- galise sterilization of all “idiots, epi- leptios, imbeciles and insane persons” confined in $tate institutions of Colo- rado after they have been declared Gapabla of procreating others of their type, was introduced in the House of Representatives vesterday by Dr. Minnie . « Denver physician e e e e e Aok ks ke ke ek ke ke gkok ok sk Ak sk ke st e ek ke e ke ek ke ko sk ke ko ke e sk ke ko ko ok ok ok ok ok ok | Radlo Editor: Kindly tell me the location of sta- tion 7SR in Cuba. What s its air- line distance from Washington and its wave length? While listening in Monday night at 9:25 o’clock I heard a stafion on about a 263-meter wave band. A woman was whistling “The Glow Worm,” ac- companied at the plano. Kindly tell me what station was transmitting it. —PHILIPS SMITH. Station 7SR I8 in Ella, Cuba. Its wave band is 309 meters. The air- line distance from Washington to Elia is 1,178 miles. A woman whistler broadcast from WCAP Monday night, but “The Glow Worm” was notein her program. Radio Editor: What station broadeast a concert by “Joe, Jim and Jack” between 9 and 10 o'clock Tuesday night? The announcer, between selections, read telegrams from the East commenting on the excellence of the broadcast, and told of a long-distance call from a point in Michigan congratulating the station.—W. R. M. Have no record of the activities of “Joe, Jim and Jack"” at the micro- phone, The fans may be able to an- swer your query. Radlo BEditor: Being a constant reader of your ra- dlo query column I would like you to please tell me the airline dis- tance of the following stations, as I recelved them Monday night on my one-tube set. 1 heard Wendell Hall, he red-headed music maker,” say, es, sir, this is station WSB, At- lanta, Ga." I also heard the Gold al station WCCO, St apolis, about 11:30 o'clock. At mid- eard a station announcer say Davenport, Iowa, the sun set ——"1 could not get the rest on ac- count of code interference. Please answer this in your column.—MRS. G. DELANEY. | The airline distance from Wash- ington to Atlanta is 542 miles. The distance to St. Paul is 935 miles. WOC is 737 miles. Radip 1ditoy: I woilld appreclate any information on two stations I heard Monday night. One signed off at 10:09 (mountain time), the first letter being K. The other signed off saying it would be on the air Tuesday at 10 o'clock and would broadcast the funeral services of an archbishop. I recelved these along with nine other stations, in- cluding WDAF, WOS and WSB on my one-tube set—JOHN WOODHEAD, The first station which signed off in mountain time probably was KOA, Denver. Some of the fans, perhaps, may be able to identify the other station. Radio Editor: Can you or any of the fans give me the call letters of the station which signed off at 10 o'clock Monday night ‘The Watch Tower Station’? —C. M. B. WBBR, Rossville, N. Y. is Watch Tower Station.” “The Radio Editor: Could you tell me if there is any statfon in Illinois with the call letters WORD? 1If so, what is the city and air line distance from Washington?— is in Batavia, TNl Tt is operated by the People’s Pulpit As- sociation and broadcasts on a meter wave band. The air line dis- tance from Washington to Batavia 0 miles $50,000 PEARL STRING FORGOTTEN BY WOMAN Marquise Leaves Gems Under Pil- low When Sailing—Located by Radio. By the Associated Presa. NEW YORK, January 15.—The Mar- q'Orgeix_ sailed on. the 1i France yesterday with her husband and two. children and left under her| pillow In the - furnished apartment| they had been ocoupying hers for the past three months a string of pearls valued at $50,000. The marquise in- formed the owner by radié, and the pearls were turned In to the police | lost property department, pending| further instructions from the mar-| quise. auise e e Kentuckian Gets Russia on Radio. John Riehl, a real estate operator | uf , Ky., reported receiving nt transatlantic | tests stations in Petro- | , Berlin and Scotland on a five- tube neutrodyne recefver. T the first recorded. recention broadcast program from Soviet sla. ——— % Policeman’s Fingers Bitten. Special Dispateh t6 The Star. EW YORK, January 15.—Patrol- man_Patrick Collins tried.to stop a| tussle over seats In_ the “L,” and| appeared vesterday in West Side Court | with dages swathing badly bitten | finger: David Martin, years old, | dimin held in | 00 s by LOOK!! The Wonderful Long Range STEINITE Crystal Set 555 Complete with phones, aerial wire, ground wirg, in- sulators, ground clamp and the wonderful Clamp. : 9.00 DOYLE’S 6th and Mass. Ave. N.W. Open Until 10 P.M. Doyle Aerial This is our first anniversary and our phenomenal success has been due to the large response of the patrons who have believed in our policy of “small profits and quick turnover.” We know of no method that we can show our appreciation for your patronage than by offering these wonderful low prices on positively guaranteed standard radio equipment. Buy these wonderful offerings and share some of our profits. RADIO APPRECIATION SALE e ether world r_wor There | pecause of a certain opposition to imateurs | negative charges from the negative of the | flament lead, but sincs the grid re- g onl¥ | turn {s connected with the positive ore and more|sije of the fllament circuit the nega- equipping their “labora- | tjvg electrons are attractéd to the —some in cellars, some in at-| glament ciroutt. S Homemane | Fundamental Grid Cireult. ansforming | This is the fundamental detéctor t, they | grld circuit, regardless of whether I tests | it is used in a simple detector cir- s the country. |cuit or in a cirouit with radlo fre- wdio dream that | quency ampiication before it. A have his If a simple detector circuit is used, nd wat- | the coil Shown will simply be the con- | secondary coil of & varicoupler, a ace. The { loosé-coupler or other tuning instru- roximating | ment. In the sinsle-circuit type of radio | recelver the coil will act not only as | the secondary coil, but also as a NOTHING MORE TO BUY Works on Any Kind of Aerial, Inside or Outside DOYLE’S 6th and Mass. Ave. N.W. Oné Square East of Tth Open Until 10 P.M. Hilco Variometers, Low-loss, $6.00 regularly ........ Hilco Adjustable Low-loss aricouplers, $8.00 regularly. .. 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Order a carron of Sunswees Prunmes today. them as suggested below. Then setve for tomorrow’s breakfast. A Quick METHOD TO COOK BREAKFAST PRUNES Wash SUNSWEET PRUNES, cover with bat waser and aliow to seak ont % bbe sarmme water in wiich they weve $5.75 regularly ... CENTRALIZED POWER HIT. | $18.50 Regularly t Wadsworth Sees Serious Gov- | ernmental Trend. ok e e dede e ek Ak ke sk ok ok ek sk ke ke ok sk ko kA Ak Ak Sk kA Ak e Bank- , said cen- | hington is P trend of the times. | r cited proposed legislation ablic all of the data which | y the internal five or would I sul every ‘Westinghouse Rectigon Charger with bulb.. $14.95 Electric Soldering Irons $1.50 Reg. Prompto Push Pull Filament Switches 50c Reg. man’s h chance for a | ome tax this year, th said, but he predicted e Treasury next year, | ate for a tax reduc PAL PHONES $3.50 Regularly, $1.65 Low-Loss Condensers .005 23-Plate One ‘hole mounting, 2 = $1.79 Battery Cables ‘With 5 leads made of phone cord wire. $1.50 reg. 50 C 10 ft. long, Complete Set of 8 Engraved ‘Binding Posts 75¢ 29 C Regularly shick quJ-:lIt it of the desived A ligle oraxge pecl, lemen “sice or sich cinoamon i 2,...,/....,..'."’ PRUNES FOR CONSTIPATION Prunes are nature’sown laxative. * Other fruits and fruit juices Docrors here are point- which lack the bulk and natural fruit roughage of prunes will not serve the same putpose. Bacon, eggs similar <coacen- Rheostat $1.25 Regularly, General Radio Longswave Superhet- erodyne Transformers. Ry, 9275 Regularly, Binding $1.00 Regularly 15¢ .001 and .00025 FIXED CONDENSERS 1c Phone Plug Holds Three Phones and Loud Speaker Pyramid TreatmentsHfford Endun‘ngflelieftoé‘u [ferers There's comfort in every box for the patient. They contain active ingredi- ents that relieve the pain and iching and are casily applied. Pyramid Pile Suppositories with their soothing, cocoa butter base and their time-tested healing properties, have brought enduring relief to thousands. They will do the same for you. At Your Druggist. SUNSWEET CALIFORNIA Post PRUN ES 1c. Radio Exclusively CALIFORNIA PRUNE AND APRICOT GROWERS ASSOCIATION © ey : Fke Rk Ak Rk Ak Ak Ak ke ok Aok N OO ORI OO OO0 OO0 OO OO0 OO YOO 28