Casper Daily Tribune Newspaper, December 28, 1924, Page 6

How to Improve Feed-Back Set VARIABLE RESISTANCE CONNECTED TO SET INCREASES VOLUME, By J. F. J. MAHER. The regeneration control system of the Filter Tuner can be applied successfully to any type of inductive feed-back circuit. The tuner de- ecribed in this article and shown in the accompanying diagram is the stamdard primary, secondary and rotary tickler, popularized under vari- ous commercial titles. It has the instability of all regenerative circuits working at highest efficiency in that it bursts into oscillation whenever the circuit is disturbed. To overcome this deficiency of the set we found it necessary to control the feed-back with a variable resistance, which not only made the set absolutely stable, but also increased the volume of the signal by providing for closer coupling between the tickler and the secondary. The function of the variable re- sistance across the tickler or plate coil is*to strengthen or weaken the magnetic field produced by this coil without disturbing the con stants of the rest of the circuit which invariably accompanies a change in the position of a mov- able tickler coil. In a circuit em: | ploying the variable resistance con- trol both the tickler and secon- dary coils occupy fixed positions at maximum coupling. It may be ob- served that a signal increases in volume as the rotary tickler is turned up to a certain point, but that it“is_impossible to pass this point to séture more volume be cause the set goes into oscillation. ‘With our system this point of os- cillation does not occur so far down on the scale of regeneration. HOW IT WORKS. To understand more. clearly why the variable resistance helps to ob- tain more volume we Must know something of the process that goes on in a regenerative set. When ® pulse arrives at the grid of the detector tube {ft produces a change in the current flowing in the plate circuit. This current, flowing in the tickler coll, produces an eleo tro-magnetic field which, in. turn, establishes another current in the secondary. It is seen, cherefore, that the set is performing as a re- lay or booster, with the serial im- pulse reproduced back into the sec- ondary from the tickler. The ondary and the point of “spilling” is restricted by the resistance. With this method of controlling | Teseneration a signal of muc3 | greater volume can be obtained GET GOOD RESISTANCE. A further advantage, and one that appeals to everyone, is found in the greater freedom from distortion in yoice and music. As Filter Tuner an outstanding cha acteristic of a set equipped with a good variable resistance con trolling the tickler feed-back ts it iruly remarkable purity of tone. The variable resistance have'a continuously variable range between about five-thousand and twenty-five thousand ohms One type of resistance using a c pound of powdered mica and gra phite has been found to be highly suitable for this work where pre cision contro] is needed. Inasmu az the successful operation of th set depends upon the eftfictor ith wi such good res! ‘Tuner. i The circuit shown in the accom-/ panying illustration fs one of the simplest All three coils can be wound uponsone tube of cardboard cr bakelite, thfee or three and a half incHes in diameter. There aro combinations of windings The common several which will work well. arrangement is ten for the pri-/» mary, fifty for the secondary and trength of the reproduced cur- aires if tifty or sixty for the tickler rent, however, depends upon the) distance or coupling between the| tickler cofl and the secondary. If the coupling must be maintained at | Inspector Tests Each} Radio Transmitter | a distance in order to keep the set from oscillating it is clear that oniy a smal] amount of the field produced by the tickler will ener- gize the secondary, In the case of the rotary tickler weak coupling is obtained by turn- {ng the rotor to a point approach- ing a right angle from the second- ary. By turning the rotor the con- stant of the secondary is charged or detuned because the electro- static relation and the mutual in- ductive values are changed. This fs an objectionable feature which Prior to the establishment of the broadcasting service radio inspec- tion work was confined almost en- tirely to the marine service, The advent of broadcasting not only necessitated inspection and careful adjustment of the broadcasting stations, but required an extension | of this work to other stations tu prevent interference and insure as far as possible satisfactory recep- tion by the broadcast listeners. During the fiscal year 1923 there were 6,988 inspections made of ship makes it difficult to log stations. As said before the maximum feei- stations; in 1924 the number in-| creased to 7,727. There were 1,5 back with this form of control is|inspections made of voluntarily re: tricted by the border of oscilla- | equipped ships. n. For the purpose of inspecting By adding the variable resistance | stations, examining operators, and and turning up the rotor to abso-| investigating complaints, it was lute maximum inductive effect the necessary for the field force to| fullplate effect is fed into the seo- visit 355 cities. | INSPECT YOUR SET REGULARLY A factor of the ideal radio set is¢tube set should provice ee with one or two spare tubes so reliability. Ruggedly designed ele |i ar ne is not placed in the unfor- | ments prevent breakdown from /tunate position of having the set ordinary use and wear. Careful/out of commission due to tubo maintenance assures constant sup | breakdown just as the programme ply of fillament current and plate | which he is most anxious to hear potential The owner of a multi-| comes along. | Double assurance of reliability is - secured by a monthly inspection of Station to Get Slogan |the antenna, examination of all con-| Station KTHS, at Hot Cprings, | Bections, testing of all batteries and Ark., is expected to be christened yercomplete dusting and cleaning of n New Year's Eve, when Secretary | th® 8° of the Interior Work will act as| Design, which assures selectivity “godfather.” This station, being lo ®Nd,simplicity of adjustment, de- cated in a national park. it is be Pends.upon a good selection of ap- f one mile. system used to cross the flere The chiet difficulty in the latter attempt was found in the timing ynehronizing of the two ma- Two revolving cylinder and another in New n by electric motors ne same speed. If a chines der from which the picture is an automatic device attached to the receiver cylinder rétards or advances the speed of it to keep it in exact step with the transmitter Actually the photographs a sent through the medium of photo- electric cells, which change the varying intensity of the light’beam passed through the film, into a radio signal of dots and dashes which reverses the process on the receiving end where the light beams are recreated and played upon a sensitized film for reproduction. It is remarkable how perfectly the engineers controlled the two hundred kilowatts of power by to give greater yolume and clearer tone. change occurs in the speed of the| Transmission of pictures by radio from London to New York marks a milestone in the progress of communication engineering. Spanning | the Atlantic, however, is not in itself the marvelous part of the achieve ment, but rather the ability to send pictures by radio if only a distance | 2Umb people to communicate over ocean {is similar to that by which hs were sent by wire during the convention, with the sub-| a high-powered radio transmitter and sensitive receiving through space, while he was manip- twhich the signals were sent across the ocean, and how pertectly they were intercepted and reproduced in picture form. The system uses siandard ‘radio telegraph apparatus, which is in itself a tremendous ad-, vance because it means that no! special transmitting or: receiving) This popular hook-up can be improved by a resistance such as tHat used in the Filter Tuner The zig-zag line and the arrow across the rotor coil indicate the position of the resistance. When it is used, the rotor coil is lett in the position shown. For the first time, and largely through the instrumentality ot Major J. Andrew White, the radio fan has come to the fore as @ backer of the Red Cross in its annual roll call. Aided by 4 committee of national prominence, Major White, has not only put roll call reminders on the air at fre -{atervals, but through him and big associates radio stores in all sections of the country have vol- upteered to serve as enrolling sta- tions ‘for Red Cross members. ‘These. memberships, while seem- ingly small in individual stores, are large in the aggregate, and through the co-operation of the Red Cross radio committee, store owners and announcers at the various stations, the of fans are today figuring as one of the livest es bride ra tant groups to place their in- Fiuence and support behind the work which the Red Cross is do- ing for disabled veterans and their families. _ Major White has just issued to all fans a “last call” for the record- ing of. Red Cross memberships via the radio stores. Visble Radio Me Scientists Hear Electrons Flow to Converse Another application of C. Francis Jenkins’s radio vision has been dis- covered in a means for deaf and long distances. If radio vision is perfected, moving pictures of the transmitter’s hands could be flashea ulating his fingers to make the deaf and dumb alphabet. On the screen, the receiver could read the letters and phrases just as he would from the moving fingers themselves, and in turn would transmit his reply, making practical a deat and dumb telegraph system. / Jenkins is having some difficulty, equipment will be necessary, and} these stations handle picture mes-| however, with the practical use of ages in the ordinary course of the| his radio photography and radio S work. letters dug, to interference with With the new system it is likely! that the handling of ordinary mes-' Broadcasting reception. Recently sage traffic will be speeded up| While sending some radio letters greatly, because {t will be posst-| bie to send long telegraph code messages as photographs. Inter- national business will be benefited | slso in the case of contracts, and documents needing signatures of men across the ocean. gSuch docu- ; ments can be flashed ‘ose in a | few moments and returned with the signature attached. Officers of the! Navy afloat and ashore are doing all they can to eliminate interference in the inter- est of efficiency and in aiding broadcast listeners. During the past year over five per cent of the old ship spark sets have been re- | placed with tubes, practically all new ships are equipped with tube transmitters, and naval operators | have been ordered to tune loose- coupled receiving sets correctly. Another effort on the part of the naval radio personnel has been to eliminate harmonics from high powered shore stations. Commandants of all naval dis- tricts have been ordered to conduct reception tests in their districts to determine whether or not naval How To Find Trouble When a set fails to produce a signal the trouble may be caused by incorrect connection of “A” or “B” batteries, defective tubes, Meved, will be of service to the Goy- paratus and the amount of the in- ernment in many ways, and the In- vestment, made, but neat installa-| terior Department has been invited |tion and relfability are possible | to make use of it when occasion | only if care is taken in the opera- arises. tion of the set. short circuits in the set or serial, broken or loose connections, fray- ing of the loud speaker or phone cord, or failure of the spring ten- sion in the sockets or phone jacks. HOW THE NAVY ELIMINATES INTERFERENCE FROM CODE arcs and sparks are causing inter- ference attributed to the Navy. In| Honolulu, it was recently demon- strated that interference charged to naval stations continued when they were off the air, and eventu- ally it was traced to a violet ray machine, \ from the Naval Station at Bellevue, D, C., to the radio snow at Ward- man Park Hotel in tie early eve- ning a number of complaints from indignant fans came in. They ob- jected to the curios sounds emitted by his transmitter, which they said sounded like a generator with a flat wheel and interfered with broadcast-reception materi- ally.. Due to this fact the inventor re- fused to repeat the transmission of the radio letters, even though Sec- retary Wilbur of the Navy, and other Government officials. were preSent to observe the apparatus in substances result from the different noise is, therefore, a fundamental characteristic of the electron. ‘These facts were brought out in a paper read by Dr. A. W. Hull, a research laboratory engineer, at the ann-1a] meeting of the American Physical Society at Ann Arbor, Mich, describing experiments con- ducted by Dr, N. H. Williams of the University of Michigan and him- trons. = sn Me E 4 The noise, due to the electrical oscillation which is set up by the impacte of the individual electrons on the plate, is known as the Schrot effect, and was predicted on theo- retical grounds by Dr. Schottky, of Berlin. The energy of each blow is extremely minute, but, like rain drops, the energies of the many in- dividual impacts add, and their sun becomes very ‘large. - With suffici- ent amplification, the blows may self, in which they listened’ to elec-| i. operation, It was expected that this new means of radio communi- cation would not interfere with broadcasting, but it may be neces. sary to give Jenkins a separate wave length for the continuance of his {mportant experiments. produce a roar like that oMNiagara. HEARS ELECTRONS. To listen to the sound of the electron is a feat in itself which lgives an added charm to the |vacuum tube. Listening to the SHORT WAVES That the low waves possess great: commercial possibilities is evident by the action of the Department of Commerce in licensing the first independent radio telegraph com- pany to carry on long. distance, short wave commercial communica- tfon between this country and Burope. The station.{s lecated at Tucker- ton, N. J., and will operate pro- visionally on 90, 98, 97, 100 and 103 meters. “Receiving | stations have been erected in Buenos ‘Aires, Paris and Berlin, and if the expe: ment proves succesful it is. possi- ble that the two-way communica- tion will take place. The advantages of using the low waves are numerous, the most prominent of them being the fact electron, however, is but incidental to the studies which have been made by the scientists. ‘ The electron is the unit FOR DISTANCE Se teeairea tit ppg tee The. | of electricity and the determina tances, the almost total absence | tion of its electrical value sien " | utmost importance. Th drop: Seusries er height thi tt method, devised by. Profe: Milt. py cictat aay kan, in the physics lahoratory of : ce Resistance Amplifier) science its tirst accurate measure: ments of the charge of the elec Resistance coupled ampliffers | are, however, it is desirable that produce the purest audio frequency | they be checked by some independ- tem over transformer coupling is| Millikan’s method of measurin; lessened somewhat by the increase | the charge of an electron is basi transformers, which makes it/electric charges on minute oll necessary, therefore, to use at least | “droplets.” These droplets are so pling to obtain a signal equal in| causes them to fall only a quarter 8 to that delivered by the/of an inch in ten seconds. the University of Chicago, gave . Gives Best Tone tron. Accurate as the experiments tones. The advantage of thie sys-| ent method. in volume which is obtained with on the influence of gravity and of three tubes with resistance cou-| small: that the fect of gravity they are transformers using only two tubes. | about three hundred-thousandths of properties possessed by the atoms according to the number and arrangement ‘of ‘the'electrons they contain. The vacuum tube amplifier in which the amplification is carried to a hun4red-thousand fold, and with which # million fold can be reached, makes this possible. The sound produced by bombardment of the plate by electrons, released from the hot-filament. It is these electrons, the smallest known particles of matter, which carry the current and which make the operation of the tube possible. electrons is caused by The Property of ‘electron emission, a an inch in diameter and are ob- served in a powerful beam of light with a small telescopes They are then seen as specks of light against a dark background. In the formation-of these smal} drops with an atomizer occasionally one becomes: charged with friction, » it y carry an additional tron. If then the droplet is, be-* tween -.two plates. it--will behave differently. from the uncharged particles. Those which.are not charged will fall. The charged particles will be at tracted to the positive plate. 8y the use of the proper voltage be- tween the plates these charged par- ticles can be made to fall- more slowly, held stationary or caused to move upward: If two electrons in: stead of.one are held by the drop- let the effect is doubled. Measure- ments made by this method _ gi the value of the electronic cha very exactly. In recognition of the importance of this work the Noble prize in science for last year was. awarded to Professor Millikan. Radiation of Receiver Distorts Reception \When two radio frequency cur rents flow in a circuit and they are of only ‘slightly different fre- quency, they produce what is called “beats,” or @ cutrent of a third frequency, which is audible, Sim- ilarly, when two notes are struck on. mousical instrument their com- bination prodvces another tone. When a: radiating receiver is op- erating it produces these “beats” in other receivers when i is tuned to the wavelength of the transmit- ting ‘station. During the trans- Atlantic t the ether was filled with thi offending waves from this type of receiver, which was re- sponsible for the squealing. RADIO ROBERT _ -:- CAN YOO SIT THERE AND TELL ME IT DONT Ger COLD IS eRe f-1 IES DWE SO MUD4IN ALL AY LIFE — THE CAPER. 1 Steet 1 THE the great number of beautiful recety. Woman’s Influence (}i22 Soa ene oe bee “4 p of deale in Design of The New Radios which rig’ become t oa must be concealed. Deve The influence of woman's inter-| the dry-cell type of va est in redio can already be seen ‘nmud} {t possible to design —_ sets, such as the Trirdyn special, in e necessary batteries could an idea} radio re s value -as rument of harmon- roundings and etract from, the Sensing this ree of her impression: talnment into t rather t usly add to, able feminine ingtinct, the woman of the house insists that the radio cab- inet be beautiful In execution and of a design and finish that will be in keeping with the surroundings in which she ‘intends to use it. It may not be such a far off day when the woman of the house will be decidely the dominating influ- ence in the merchandising of radio. Radio set gales will increase when solicitors realize that the woman of the house has the major part in the decision of what 1s to go into her home. This fact is well known in the Plano and furniture shops. Saleémen who are making house-to-house so- Ucitations for sales of radio se’ find they have to deal almost entire- ly with the woman of the house. If the woman is convinced a sale ts realifly completed. “Blue Book’’ for Radio Fans. Issued By Mandfacturer Radio advances so rapidly {t is with difficulty that one can keep up \ There’s a Draft in His Set with it. Text books of last year, in This accounts for the many editions of “Simplicity of Radio” by Powel | Crosley, Jr., who has'been referred to as “The Henry Ford of Radio,” be. cause of the unique position he ho:ds in the radio industry as head of an organization making thousands of Fadio Sets a week. In this, the léth editio: hi & complete revision % P. SUNDAY, DECEMB! electrically -charged © many instances, are obsolete today. | SHe 28, 1924 of the text and illustrations as_well as the attractive cover in biue.\It is: known ag ‘ The Blue Book of Raslio.” The purpose of this. book {eto treat the subject of radio in a non-tectini- cal style, using simple-words the most romantic of the modepii aci- ences, It treats of radio from the most up-tc-date standpoint “and is illustrated with nearly one-hundyed and fifty diagrams, drawings. and pictures. et seeds The text is ‘divided into.two-parts. Part 1 deais with the fundament while part 2 *goes more fully! inte the details of radio, through in a non- facts -of electricity and trouble hunting are two features which should appeal to everyone who contemplates owning a radio re- celver, Ave eee Try a Classified Ad for results. geal ey Aaa 2 ine ones 2d od Classified Rates Two cents per wort-or ten‘ cente per line. re NO AD LESS THAN 80/CBNTS. Five average words: used, as a basis of estimating a line. BLACKFACE CAP HEADLINE Fill, be chargea the space of twe ines. | All charge¢ udyertizing will be bouxed “set lines” irrespective of the number of words. CORRECTION OF CLASSIFIED ERRORS. Ao The Casper Daily ‘Tribune’ will nor be responsible for more than ne incorrect insertion of any ad- vertiseracnt ordered for more than one time. Errors not the tault of the advertiser which cleariy lessen the reat value of the advertisement witli be rectified only by publication W-thout extra charge within Cays after insertion. No re; tion will be made when the error does: not materially affect the sense @ purpose of the advertisernent. CLOSING HOUR. Went Ads to be classified ly Must be in the Caper Dally Tribune ‘ant. Ads received after 10 to 12 a. m. will be inserted uncer the head “Too Late to Classify.” TELEPHONE ADB. °\'! ROAR OF NIAGARA PRODUCED BY, |, custut sivendon wii wegtres PARTICLES FROM FILAMENT Scientists, who have recently succeeded in listening to the electron, now believe that ali matter is composed of electrons and that different is received over the Tut we cannot guarantee. re “OUT OF TOWN ADVERTIS? MENTS. Must b.. accompanied cheok ‘in full payment the 1e. Note the foregoing instru ebout counting the words and the rate per word for the Casper Dally ‘Tribune. é we the average person will understand: - = 50S HELP’ WANTED—Female | WANTED—Help’ for general ‘house spas 426 E. Eleventh: Phone WANTED—Piano teacher. 220 & Wolcott. To WANTED—Honest, neat; capable white maid, for generall: house- make Must"be good cook, * 642.8, rant, nce Nl ae Se a LD WANTED—G! m% general hi work. Hist Diines Prenat HELP 'WANTED—MJ 00 A MONTH; everyday -househol@_ rural-and small town distri s money needed. Million dotie® firm behind itsAWrite for particdlars and state --territory - desired. *"'D. K, JOHNSON, 60%. Wi Lake) -Chitago. ee MEN. wanting Forest 1 Clerk and other Government pos! Hous. "Write -for-free particulars, Mokane, D-115,,Denyer, Colo. \ FIREMEN, BRAKEMBN, beginners $150-250. (which -position?)...Rail- way, Box Bilt, Tbune No SALESMEN WANTED WE WILL haye vacancies for two or. three-live salesmen after Jan- uary lst.. See Mr. Nolan evenings, 8 to 9. Nolan Chevrolet.Co.ta $75 .A WEEK. .MAN,OR Wi! wanted" with ambitfon an. ue. try, to distribute Rawleigh'’s use hold Products to steady users. ve eral fine openings. in nearby..cities and towns.. We train and heip -you 4 ba set eake: Up $100 a, week ore. 'O expe! ice ‘necessary. Pleasant, profitable, dignified work. Write today, Wi T.° Rawleigh: Co., Dept. WY 553, Freeport, Ill. SALESMEN—Best men make $250 weekly selling new specialty, AT retailers. New men guaranteed $35 & week and expenses agatust com- missions. G. STANDARD. MFG. CO., Cedar Rapids, Towa, i SALESMEN—Opening snow. | Per- manent. Wholesale house, long established, selling’ retail) trade. in general. lines. . Liberal contract to Producer. Tho, Miles ¥. Bixler Co., Dept. 461, Cleveland; Ohio. AGENTS WANTED pasa hy beat hl aad AGENTS WANTED—District resentatives “and loca} agente, men and women by a large manu. facturer to sell direct. to the con- Sumer, part or full time, He of Patented NOPULOUT - shirts. and shirt-walsts on lberal commission basis. Many agents: making $15 NOPULOUT be 2 UT SHIRT CO., Box -96,Hazleton, Pa. SS POSITIONS WANTED B WANTED—Janitor or -portér’ wor! Phone’ 1138, Ni ot pelibat 3 eS ap eet lady -desires.care:.of children or invalid «durt a Phone 1594W. 2 7 ere eS MAN wants job on ranch. Call 1802. m $$ WOMAN with child-two years old, wants work, Will-considee $16 | per month and “¢htld’s ‘board. 2096 Monday before. noon. a re WANTED—House work or ordinary | Work, by«gitlisby- day or week. |Call 1416 By Se¢ond. SERVICES OFFERED ee MARCEL and hob curl, complete, ic, . algo eae Coane ate Phone 2461J., 129 8. ergocd: GET the best in body ana ler repairs st K Spiteri Fender Shop, 425 W. Yellowstone. . ™~ pw é "Ss? Gece ey Ss bpp o Pray a i fo? i Boe ee a peed