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About The Sunday Oregonian. (Portland, Ore.) 1881-current | View Entire Issue (Dec. 31, 1922)
7. RICH REWARD AW AITS RADIO FANS WHO MASTER MORSE CODE Many Interesting Things, Tossed To and Fro in Ether on Land and Sea, Are Made Available to Owner of Set Willing to Attend School or Take Lessons at Home Chart of Letters and Buzzer Are Essential BT SAUL EMANUEL. SOONER or later there comes to every radio enthusiast the de sire to learn the language of the dots and dashes. "While musical concerts and lectures and the like are most entertaining to the lis tener, he feels that there is a wealth of information passing "over his bead" because he can't read the mysterious signals. There are many things of great Importance being tossed to and fro in, the "ether" by the radio stations on land and sea. With -a little patience any radio fan can master the International Morse code, which is used in trans mission of radio messages. It may be months before he will be able to copy the signals sent by fast com mercial operators, but a few weeks of practice will give him the ability to read those sent at a medium speed. ; One method of learning the code is by attending a radio school. This, of course, U the quickest way. How ever, one a teach himself if he will apply himself to the task. ' The fan who wants to learn the code should get a chart of the let ters and a "buzzer" set. Both can be procured in any radio shop. The buzzer set is nothing more than an electric buzzer operated by a dry cell and an ordinary telegraph key. The first step is to memorize the code, letter by letter. Each letter should be fixed in the mind, not so much by remembering the dot-and-dash combination as by learning the sounds they represent. For instance, take the letter "C." On the chart it is found to consist of "dash-dot-dash-dot." But don't memorize it that way. Hake it a combination of sounds, like this, "dah-de-dah-de," Just as they taught you to learn words by sounds instead of spelling them when you were a child. When every letter in the code is fixed In your mind begin to send mem on me ouzzer set, rememDer- lng that a dash is equivalent to the time taken in making three dots. Sen'd each letter slowly and listen to the sound produced by the buzzer. The letters of the code Bhould be mastered four at a time. It will be RADIO QUERIES Editor Radio Department (1) Can I regenerate my telephone receivers with dry cells? (2) For lons-diBtance reception is it advisable to get as long an aerial as possible? (3) How can you tell if a tube Is wear Ins out? R. S., Portland, Or. (1) Yes. The current from as much as four dry cells can be sent through the receivers for a short while without burning the receivers out.' However, "the current must flow through the receivers in the right direction; otherwise the re ceivers will be ruined. It is advis able to send the receivers to the manufacturers for remagnetizing them. (2) Up to a certain limit only. It is not advisable to have an aerial so long that its fundamental wave length is greater than the wave lengths of the received signals. For the best reception of 360 to 400 me ters the antenna, including the lead in wire, should not be more than 200 feet in length. (3) Tubes work practically about the same throughout their life. It wears out when the filaments burn or- break. This usually occurs sud denly. There is no method by which you can tell when the tube will wear out. . . Editor Radio Department I would greatly appreciate details of a device for the elimination of spark and aro-llght Interference. R, U P., Walla Walla, Wash. Unless you are located too close to the arc light or the spark sta tions you can overcome their inter ference to a great extent with a selective regenerative receiver. If, however, the Interference Is too close there is practically nothing you can do to overcome it. Regarding the arc-light interference, would advise you to stretch the antenna and the lead-in wire as far away from the arc as you can. A "wave trap" may help you a great deal. This is noth- i n 9 ... I. nn.n.mnn. K coil around; which is conneoted a .0005 mfds. variable condenser. The whole thing is placed in seri,es with the antenna circuit. This device is very efficienit for overcoming inter ference from spark stations. Editor Radio Department (1) Could en aeriotron W. D. 11 dry-cell detector tube be used with a tube adapter in a Clapp Eastham H. R. set InBtead of the C-300 tube without decreasing the 'effi ciency of the get? (2) Does the W. D.-ll tube take the same grid leak and grid condenser as the C-800? - t (3) How does the Clapp-Eastham set eompare with the other single circuit sets on the market? , A. R. Portland, Or. (1) There will bs no difference in the efficiency of the set. (2) The peanut tube usually re quires a little larger grid condenser than the standard tubes. One about .0005 mfds. is recommended, and a leak of about one' megohm seems best in most cases. However, a lit tle experimenting will be necessary in the case of the grid leak. (3) Comparisons of various re ceivers cannot be given in' this col umn. Editor Radio Department (1) Can I produce regeneration in my receiver with only one variometer 7 (2) Using a one-stage amplifier, would I have to. have a large B battery or would two batteries each 22 volts do? (8) Will size 22 double cotton covered wire work for winding a variometer? K. T.. Athena, Or. (1) Tes. Place the variometer in lilt? ait; Mivuiu (2) Either the two batteries or one of 45 volts which is tapped for two batteries are used they are con nected in series, with the positive of one connected to the negative of the other. The plate circuit of the detector tuDe is connected to izya vftlta. wfcilA .that nt thft amnKfipr is onnected to the entire battery of 45 volts. i) Yes, this size will give you excellent results. Editor Radio Department Am using ti three-honeycomb regenerative receiver and it doesn't work very good. I only hear you once in a while. Can you give me a hook-up of a circuit which you tains, wm wotk better? E. S., Vernonia, Or. Your fault is probably due to not understanding the correct tuning - of such a set. There is no reason why you shouldn't be able to hear the Portland stations with your re ceiver If you adjust the various units correctly. Of course the trou ble might lie in your tube, or the batteries, both "A" and "B," might not be correctly ponnected. Try re versing the polarity of the A bat tery. This will often make a great difference la the degree of recep tion. Editor Radio Department I have a honeycomb receiver used in connection With a detector and two-step amplifier and would like to know if you could kindly send me a hook-up using the honeycomb coils as a ehort-diatance tele phone transmitter. Also would like the Above for both telephone and C. W. A- M., Astoria, Or. Every regenerative reoeiver will Itct a a, transmitter for. short, 4ia- found after some practice that the letters will form in your mind auto matically, and when this stage Is reached the speed can be increased. Don't try to make words until you have mastered the letters. With all symbols memorized, the beginner should, practice sending with a book or newspaper in front of him, translating the words into the dots and dashes of the buzzer. Between each letter is a short space and between words a longer one. In 'a - surprisingly short time smoothness and speed in sending will develop. " Now begin to listen to the tele graph stations. Of course they will be too fact for you to copy. But jot down on paper as many letters as you can recognize. Also get some friend to take up the code with you and practice transmitting messages back and forth with him. It won't be very many weeks be fore you will be able to pick more and more letters out of the air, then whole words, and finally en tire messages. It will require constant applica tion to learn the code. At least one hour a day should be given to the practice of sending the letters and, if possible, receiving to your friend's sending. A good deal of practice can be had by listening to the amateur stations. While many owners of these are quits expert in transmit ting the code and will therefore be too fast for the beginner, there are others who are only learning and will send at a speed slow enough for you to pick out a letter or two, or even words. You will find that sending is much more easily learned than re ceding. But the latter will come finally, though there will be times when you will become thoroughly disgusted, thinking that you will never be able to learn. Besides the code, there are cer tain abbreviations that are used in ternationally and which should be learned, as they are used a great deal in the air. They are combina tions of three letters which repre sent whole , sentences. A chart of these can be,procured In any radio shop. AND ANSWERS tances, provided that the plate cir cuit control is so adjusted that the tube will oscillate. By connecting a key in the lead-iaor in the ground wire the outgoing energy may be broken up to form C. W. dots and dashes. When a telephone trans mitter is placed in the same man ner as the key voice or muslo can be transmitted. Editor Radio Department (1) In mak ing an earth connection for a crystal set will a wire running Into a well give good results? (2) Can I connect a "peanut" tube in place of my crystal detector and get dis tant etations? U B., Lyle. Wash. (1) Yes. Attach a piece of metal plate or chicken netting to the end of wire which drops into the well. This will make a good ground. (2) Yes. Connect the grid of tube to one end of the crystal detector and the filament of the tube to the other end; of the detector. A Jumper should be placed across the tele phone posts of the crystal set. The phones are placed in the plate cir cuit of the tube. As for receiving distant stations with such a set, this will also depend on the height and length of your antenna and the location of your station with respect to nearby buildings, power lines or trees. Editor Radio Department (1) Why is copper wire used on a tuning coil Instead of iron, which la much cheaper? (2) When I turn my variable condenser j to a certain spot I hear a loud click I and the signals fade out.- What 1b the reason for this. , U S., Portland, Or. (1) Iron is highly resistant to electric currents and, as it isi not resistance you want in a tuning coil but inductance, which ifl something very different, therefore a good con ductor like copper is used. (2) It Is evident that your con denser is short-circuited, and two i adjacent plates are touching each j nthftl1 when m nvr. .Via nlota, n ' a certain position. Look through the condenser and see if the plates are bent and touching. If they arf. the plates should be straightened so they will not touch when moved. Hints for Fans. rE best- tuning of the loose coupler is given when the sec ondary turns in use are just outside, and not directly under, the turns of the primary. For this reason, pri mary and secondary windings on the same tube, but spaced one quarter of an inch apart, give, very satisfactory results. KeeD your eye on your storage batteries. Don't let them stand too long without recharging. If you charge them at home, take them to the service station at least once every year. A few dollars spent in having an expert look them over may save the price of a new battery. . Keep the tops of the elements covered at all times. The water evaporates, but the acid does not. Use only distilled water. In operating a crystal detector, it often occurs that a serts'tive spot usually is lost with the least Jar or shaking of the table. To keep a proper balance, adjust your cryBtal detector to the sensitive spot of re ception. Drop some melted wax from the top of a battery onto the covering of the crystal detector This means that the sensitive spot of the crystal must be covered. The detector will then be grease proof and cannot be knocked out of 'ad justment. If signals are much weaker dur ing reception than usual, it may be from any of the following causes: Poor ground connection. . Detector may be out of adjust ment. - Coupling between colls is 4oo loose. Loose contacts in the receiving aerial. v The switches may be making poor contact. The variable point on detectors may be corroded The condensers may be short in certain positions. The primary and secondary cir cuits may not be In resonance. Never allow unused batteries to remain idle too long. Batteries should be recharged whether they have been used or not, if a test shows that they need it. When the tops of the plates are dry the bottoms only are working. That means that only half of each plate is carrying on the action that is required of the whole plate, with the result that they are overheated and often buckle. The battery should be filled with d'stilled water so that the plates are always covered about one-quarter of an inch. Only distilled water should be used. This seems to be a minor point, but it is very impor tant, as impure water reduces the life of the plates and does not ener- giz pxonarl. MODERN RADIO SET OF HIGH EFFICIENCY IS INSTALLED AT MOUNT ANGEL COLLEGE Complete Receiving and Transmitting Apparatus Provided So as to Meet Wide Demand for Instruction. All Pacific Coast Stations Within Easy Range. - . tjUf M " I 'I Is;:. I4 '$h'th4 ' 1 n j PIH MOUNT ANGEL COLLEGE, St. Benedict, Or., Deo. 80. (Spe cial.) In order to complete its equipment of scientiflo appara tus, Mount Angel college recently Installed a radio station of modern design and high efficiency. Due to a demand for Instruction in the new and fascinating art of wireless com munication, complete receiving and transmitting apparatus are included in the station. For short wave reception there is a regenerative tuner, detector and two stages of amplification. With this set, amateur stations, within a radius of 1500 miles are easily heard. All the Pacific coast broad casting stations are also within range. Some of the more distant stations received are Denver, Colo.; Dallas, Tex.; Regina, Saskatchewan, Canada, and St. Louis, Mo. The splendid programmes broad cast by the new end powerful Ore gonlan station come in very loud and distinct, and can be beard 100 feet from the head phones. For long wave reception duo-lateral coils &re employed. With these it is possible to receive the government and commercial stations located along the Atlantic coast, as well as European stations. Time signals are received! daily either from Annapolis or from Honolulu. The transmitting set is of the spark type, . which is considered more reliable in operation than the recently developed tube transmit ters. The maximum power employed is one kilowatt. A Thordarson step up transformer, an oil immersed condensen spark gap and oscilla tion transformer are used for trans mission. The aerial consists of RADIO TELEPHONE TRANSMITS FIRST MUSIC THROUGH ETHER Phonograph Used in Development of Wireless Service for Admiral Evans Fleet Startles Operator With Real Music BT LEE DE FOREST, Ph. D., D. S. C. FOREWORD. In the year of 1905, resolving to pur sue bis experimental work further, De Forest decided to withdraw from the company which had borne his name, and. in exchange for his stock interest, re ceived something which his former As sociates considered of negligible value. How little these former associates fore saw what was to happen! For they actually surrendered the De Forest patents, out of which came the now famous three-element vacuum tube. De Forest also retained his 'engineer ing laboratory, on the top floor of the old Parker building on Fourth avenue and Nineteenth street, a spot of his torio Interest today since it was here that the inventor perfected his now famous audion or three-element vacuum tube. In this present chapter we also have the Interesting story of an experiment conducted in New xorK city. In tne spring of 1B07, for the production and distribution of electrical music, in turn broadcasted by De Forest. The produc tion of electrical music by means of high frequency generators was, how ever, doomed to an early rauure, in spite of the great sensation this experi ment created at the time In both musical and electrical ciroles. THE EDITOR. . CHAPTER III. , UP TO the year 1907, very little had been done to convince the at lar tlinr RnmA dav it would be possible for us to trans mit the voice without wires. Wire less telegraphy was already widely In use; the Morse and the continen tal telegraph codes of dots and dashes, familiar to the many ama teur operators. But a surprise was shortly to come to those who were conscious only of the dot and dash language of the wireless telegraph. My laboratory antenna was then stretched between two flag poles on the roof of the Parker building, Fourth avenue and Nineteenth street. New York city, and the im mediate use to which I was put ting this antenna was not a fur ther development of the wireless telegraph, but something entirely new. It was the radio telephone that was now engaging my atten tion, and these were . indeed busy days and nights. It was in the course of these ex periments of 1907 that the photo graph was first used to actuate the microphones of the radio telephone transmitter. The phonograph was regularly used at this time in our development of some 20 small tele phone transmitters for installation on Admiral Evans' battleships and destroyers, prior to their round-the world cruise. During those busy nights and days the ether around New York was kept thoroughly agitated with music from "II Trovatore"; and more than . one -ship's operator working with his, then newt carborundum crystal detector, had sudden doubts as to his sanity or sobriety, when above the rattle of the sixty-cycle spark he heard distinct and clear, real music or human voices. George Davis, until recently presi dent of the Wireless Specialty com pany, then, chief electrician of the Brooklyn navy yard, was among those present unwittingly at the first radio concert; and to this day describes, in his graphic way, his startling sensations when the music of the "Anvil Chorus" smote his lis i tening ear! Ino douDt, many an amateur oi that day was likewise somewhat upset by the sudden and altogether unexpected presence of musical tones iq his telephone receiver, al- & Complete radio station of Mount Ansel college at St. Benedict, Or. , Insert Rev. Benedict Barr, O. S. 1!., builder and operator of the station. four wires spaced three feet apart and la about 90 feet long from ex treme, end down to the set. The ground lead is attached to a water pipe and also to a large quantity of wire netting and sheet metal buried In moist earth. For - receiving, a 275-foot two wire aerial is used. This is ele vated 100 feet above ground. A loop aerial, composed of 100 turns on a- 4-by-4-foot frame and tapped every 10 turns, may be attached to the receiving set to demonstrate the directional properties of this style of antenna. Its efficiency can be though the way for this new Inven-1 tion had already been paved by an experiment in the broadcasting of electrical music In the spring of 1907 from the Telharmonium, In a building at Broadway and Thirty ninth street, New York city.j After years of lnderatigable ef fort and with most clever engineer ing skill, three brothers by the name of Cahill had developed a huge plant consisting of many induction alternators whose various frequen cies were those of the entire musi cal Bcale. The currents from these machines were controlled by a key board similar to that of a giant pipe organ, commingled through a sys tem of transformers, and thus syn thesized into a single highly com plex musical current, were trans mitted over telephone wires to nearby-theaters, hotels, restaurants, where one or several "loud-speaker" horns poured into the air this new electrical music. Much of it was sweet, most of it was musical; in imitation of the organ, the clari net, certain brasses and wood-winds. commingled with these familiar sounds, strains of a quality entirely novel to musicians, yet for the most part pleasing. To convert this musical current Into radio frequency and Impress on the antenna which I had erected tor mis purpose on tne root ot tne building, was comparatively simple, and a demonstration was made to receiving stations in this city. At. this period, the Telharmonic company was vigorously seeking a franchise. in Albany to permit them to run telephone wires under the streets for the purpose of distribut ing this music to all subscribers who wished the service. The tele phone' company, finding that con siderable "cross talk" disturbance was produced In their other lines, if certain cable conductors were used for these powerful musical currents, refused to permit the Telharmonic company to regularly lease or use their cables or conduits. This necessity for wire distribu tion and the insuperable obstacles there encountered, spelled the fail ure of the Telharmonic enterprise, and I sought earnestly to impress upon the directors of the Cahill company the possible solution of their problem which the radio-telephone transmitter offered. I pointed out that the question of free reception versus toll service need not be regarded as an Insuper able objection, that In many ways a free broadcasting service of "Tel harmonic" music would" be at first desirable, as affording the best pos sible form of advertising the exist ence of the new synthetic music; but that it lay well within the scope of electrical engineering attain ment to devise a method for mak ing this wireless music unintelli gible to other than, certain complex receivers, which latter could be ob tained by lease only from the music distributing company. Had this 1 view of the problem and its solution been then accepted by the Telhar monic company I have no doubt that we would have witnessed the radio phone broadcasting of music on a commercial and popular scale ten years ago,, with the still unsolved problem of radiophone secrecy long ago worked out in a simple and practical form. For. there has been, since the; la- Judged from the fact that New York and other eastern stations have been received when using this coiL The radio station was built prl marily for scientiflo purposes. In accordance with this idea a good deal of the apparatus is 'home-made. Among such Instruments may be mentioned a filament storage bat tery with automatic charging de vice, fixed and variable condensers, honeycomb and reactance coils, flicker balance, improved spark gap electrodes and an oscillation trans former composed of two-inch cop per ribbon. The various parts of the receiv lng and transmitting sets are mou'hted in plain view or are easily accessible. The student of radio is thus made acquainted with the ex act relation of part to part and acquires a familiarity with the principles involved which could be gained in no other way. Regular instruction is given in the elements of electricity and dally, systematic practice on the continental code is insisted upon. In this manner , the prospective radio operator Is pre pared to pass a successful examina tion before the government Inspec tor and fitted to erect a station for himself. The entire Installation, Including aerials, "ground," high-power leads, eta, as well as the assembling of all the apparatus is the work of a mem ber of the faculty, Rev. Benedict Barr, O. S. B., who holds a first class amateuf operator's license and is in charge of the electricity and radio class at the college. He is considered one of the best electri cians on the coast. The call letters of the college station are 7ID. mentable failure of that daring en terpriseno such financial incentive towards the solution of this secrecy problem. But now," when the ether is literally lammed with the super abundance of radio music and con-, nections. this necessity has indeed again arisen; and it will not be many more monthB. or years, before certain types of radiophone trans- mitters will be quite unheard or un- Intelligible, except to specially de - signed and "codified" receivers. i Already 'a flood of patent appllca tions, aimed at this problem, are dammed up in the patent office at Washington. But returning to the radiophone music It was perhaps the diffi culty I, myself, experienced In the early days in learning to read Morse, which was my chief incen tive to invent a wireless telephone! Consequently, I, perhaps the first wireless amateur in America (1899 1900), foresaw the Interest which the advent of radio-telephone broadcasting would arouse among existing wireless amateurs, and that for everyone -who went Into the game to read Morse there would be scores, nay hundreds, who had neither time nor patience to learn telegraphy; furthermore, that music by radiophone would keenly inter est multitudes .of listeners who would not only become good pur chasers' of audion sets, but would derive genuine benefit and a whole some pastime from this new inven tion. It was accordingly with a high degree of interest that I kept at work in the Parker building labora tory. It was in this same little laboratory, many months earlier, that I had conceived and tested out the first three electrode vacuum tubes first with the "control elec trode" a simple band of tinfoil wrapped around the outside of the bulb; then with two plates, one on each side of the filament, one the anode, the other the control; and finally with the third electrode in the form of a grid, or a perforated plate, located between the filament and anode. There, also In that same upper room, I had discovered that this three-electrode tube, which had Just been christened "audion," would TO OUR OUT-OF-TOWN FRIENDS HAVE YOU RECEIVED OTJB PRICE BULLETIN NO, I ? A HEFTIEST Brlngrs It to You. We pay postage on orders over 92.50. HALLOCK & WATSON ' RADIO SERVICE 19a Park Street, Portland, Or. Broadcasting Station-KGO Experimental Station 7X1 E. L. KNIGHT & CO. 44i Washington St., Near 12th Broadway 0145 START THE NEW YEAR WITH A RADIOPHONE IN YOUR HOME. Radio Sets and Part. - "IHI8HT WAKES DAT THE ELECTRIC WAT" l actually amplify telephone currents. In. that room, then, there was born the tiny little glass baby which was destined to rule the world of elec trical communication. Unfortunately, in January, 1908, a great fire . completely gutted the Parker building, wiping out of ex istence note books and many pre cious samples of the earliest audion bulbs which would have today shown the history of its evolution in a most interesting way. (Copyright, 1923, by C. S. Thompson. All rights reserved.) To be continued next week. Pre ceding chapters of this absorbing story of the development of radio broadcasting can' be obtained from the circulating department The Ore gonlan.) Potentiometer Big Aid in Broadcast Reception. ITntt Enable Operator to Bring; V Weak Signals. w ANY radio fans do not know that the addition of a potenti ometer will make an considerable improvement in their reception of the broadcasts. This unit comes In especially handy on weak signals, which can often be brought up from a whisper to a fairly strong audi bility. Its use with amplifiers is valuable as the ability to. govern polarity, as well as to control the exact amount of plus or minus energy, makes the final adjustments much more satis factory. . . - A potentiometer, like a rheostat, is resistance, but the difference be tween the two lies In the fact that the rheoetat Is of very low resist ance, such as 6 ohms, while the po tentiometer usually runs between 200 and 400 ohms. If we put a potentiometer in place of the rheostat In the filament cir cuit, the tube would not light up as only about .015 of an ampere would flow, while about one ampere is needed for the proper operation of the standard tube. The potentiometer Is placed di rectly across the storage battery, or in the case of a "peanut" tube, across the dry cell. Because of its high resistance, the potentiometer will not consume much current from the "A" battery, but it is advisable to have a switch to open the battery circuit wnen tne set is not in use. $ In another section of today's Issue is hown a hook-up in which the proper method of connecting a po tentiometer across the "A" battery is described. Potentiometers vary In appear ance, but they answer the same pur pose. A potentiometer has three contacts the two outside ones go to the positive and negative of the storage battery and the center one goes to the negative of the B bat tery. They can be made at home from a carbon rod, so arranged that con nection can be made to either end and a slider provided for the middle contact. . Another can be made by taking two pieces of wood four inches long and two and. one-half wide, the thickness of an ordinary box. Bore a hole for the switch in the lower center and then take a compass and draw a half circle and then bore a hole at each end of the half cir cle which Is to be the positive and negative connection. Next take a sharp knife and dig a sharp channel aoout one-eighth of an inch deep In one of the blocks that will cover the range of the switch and fill it with black lead and tamp it in until it is firmly packed Put the other i block on it and bolt toeether with ' the three bolts for which holes were : provided. For contacts for the switch you can use about 30 strong j tuem tnrougn tne woed 1 an mu tne DiacK lead. Get them as close as you can without touch ing. This potentiometer will not be as good looking as the one you buy. out wui answer tne purpose. Radio Notes. T ADIO compasses are being util- 1 ized in a number of ways, chief among which being its application to navigation. There are situated at numerous points along the east and west coasts of the United States a number of radio compass stations, separated by several hundred miles or more, built and maintained by the United States navy department, which" are almost In constant serv ice giving bearings to hlp at sea. For this purpose, the radio compass stations work in pairs, and the pro cedure is as follows: If a ship has been unable to ob tain bearings for soma time due to Inclement weather or if it wishes to have a check on the bearings which it has obtained Itself, the nearest radio compass station is called by radio. The call is acknowledged by the compass station after which the snip senas me letters MU ,for a period of several minutes, during which time the two radio compass stations which work in conjunction with each other, take bearings on the incoming signal by the use of their radio compass receiver. The two radio compass stations are con nected usually by a land wire, and station number one transmits the Radio Sale to be Continued Until Our Stock Is Sold Stock is not complete now, but if you need anything in the radio tine it will pay you to find out if we have it before buying else where. A few bargains left are listed below: i " Reg. Sale. KiIbourne-& Clark Receiver Detector and 2-stage amplifier In nice oak cabinet "B" and "C" bat- M teries included , $116.00 $50.00 PROFCO receiver, detector and 2-stage in nice ma- .o hogany finished cabinet 110.00 48. OO WESTINGHOUSB receiver, detector and 2-stage - (This is one of the best long distance sets on the market) "2.R0 Sg.OO Large size Masnavox J Arkay loud speaker horns "-J Rheostats, Framingham f .78 Detector and 1 step in nice oak cabinet, FADA. . . . 40.00 20.00 Prof co Receiver and Detector in mahogany fin- ished cabinet 40.00 25.00 Western Electric Head Phones, best grade 1S.OO -4 Federal Head Phones, 2200 ohms Holtzer-Cabbott Head Phones 4.75 Murdock Head Phones, No. 56, 3000 ohms 0.00 4.0 Murdock Head Phones, No. 56, 2000 ohms 6.00 ii.SU Knobs and Dials, Studner 3-in., -in. hole... . ..M Knobs and Dials, Electrose 8-in., -ln. hole.... l.oo .40 Red Bakelite Sockets jl-v". -' Audio frequency transformers, Federal . .oo Large eize binding posts, bakelite tops. 15 . ,Oo Every Article on Sale at Reduction of 30 or Moret Jo C. O. r.'. No Charge Acconnts. No Mali Orders Accepted for Than f l.OO. Postage Must Accompany AH Orders. THE J. It. WEED, Manager - The Oldest Exclusive Radio Store in Portland 310 OAK STREET PORTLAND, - OREGON' ALABAMA RADIO FAN HAS UNUSUALLY GOOD HOOK-UP . . Reports From The Oregonian Station Heard Clearly Potentiometer Important Feature of Set. C H'H . POT. I - t J Hook-up used by mn Alabama amateur, who reports that The Oregronian station la heard clearly with this receiver. A' FTER many experiments with various regenerative receivers, S. S. Holt of Mobile, Ala., has found one that's a "jim-dandy," as he declares in a letter written re cently to the radio editor. With this hook-up, he hears nearly all the big stations in the United States. KGW comes in "QSA" (loud) in his home, he says. As Mobile is nearly 2000 miles from Portland, there must be something to this "hook-up" of Holt's that's worth the time of any Portland radio fan to rig up one like his. Holt's hook-up is shown above. It's quite unique In that the variable condenser, instead of being placed in the antenna circuit, la put between the antenna and the telephone re ceivers. This sharpens the tuning bearing which if has found to sta- j tion No. 2. Station No. 2, using the bearing which it has determined and the bearing which has been for warded to it by station No. 1, laysj out on a map two lines, each pass- , ing through the compass station which has taken a bearing, In the direction of the signal received. These lines are extended until they Intersect, and the point of intersec tion indicates, on the map, the. lo cation of the ship. The map, or chart, upon . which this trlangula- tion is done, is laid out to scale, and laid oft in latitudinal and longi tudinal lines. The latitude and longitude of the ship can then be read directly from this chart and such bearings sent to the ship by radio. A new experiment in broadcast ing, which may change the broad casting plans of the country, will soon be tried in the station of a large Montreal dally. To technical men, the new plan is known as re transmission, and although it has been tried many times In an experi mental way, this will be the first time that it has been given a prac tical test In Tendering public serv ice. The radio broadcasting station of a Montreal daily paper will be used to re-broe.doast entertainment of the New xork stations, t ne ew York programmes will be picked up in Montreal with a sensitive re ceiver and highly amplified. The output of the receiver will then be fed into the broadcasting equip ment, and the very entertainment that Is being sent forth from the New York stations will be enjoyed by the "listeners-ln" In Montreal at practically the same Instant. The engineering problems In the Instal lation of this equipment are in the hands of the engineers of the Hutch inson Eadlo company of New York city. High hopes -a.ro held out for the success of the experiment, since it will mean a great ieal to broad casting if practical. Working on this principle it will be possible to operate two or three big central broadcasting stations wth the small er stations in the outlying districts used only for retransmission. In this way two or three stations could blanket the entire United States and the money that is now being spent on the entertainment for several hundred croadcasting stations could be concentrated on a few. mm Interference n broadcasting, which threatens the usefulness of more than 1,500,000 receiving sta tions in the United States, may be solved by a selective vario coupler, devised and patented by Alfred Crossley of the navy engineering bureau. Installed on receiving sets, the vario coupler Isolates from the maze of radio signals constantly passing through the air those which the In dividual stations desire to record and makes possible uninterrupted receiving from any broadcasting con t c i "The new vario coupler permits zero coupling between aerial and detector circuits which condition permits means for accurately tun ing circuits to any desired wave length," Crossley explained. "Under present conditions, recelv- ;!KC STORE B-BATTEI! considerably and helps to feed back the plate current into the grid through the variotoupler. If any of the Portland fans want to. rig up a set like Holt's, all they need Is a standard variocoupler, one variometer, a potentiometer, and a .0005 mfds. variable. A small fixed condenser, preferable of .001 mfds. is placed across the telephones. A very important feature of Holt's set is the potentiometer. When this is adjusted critically, signals come In quite clearly. They would never be heard, were the potentio meter not in the circuit, declares Holt. The radio editor would like to re ceive reports from any of the fans who try Oils hook-up and get suc cessful results with it. lng stations 'tuned in' for a concert from Newark, N. J., may suddenly , find the music changed to a report on the hog market from Chicago, if the broadcasting stations happen to have nearly the same wave lengths." Widespread demand for relief from radio interference has led the radio division of the department of commerce to get behind a bill .pro viding for standardization of wave lengths, now before congress. .. , O. C. Reese, fellow of the L R. E., predicts that within five years there will be at least 1,000,000 radio receiving- se.ts in the United States of sufficient sensitiveness to receive code or speech from. Europe, Latin America or the orient. The wave , lengths used will be about the same as have recently been tried- success-.. fully between Java and Holland. ; He and pther authorities pre--dlct that the one to 60-kilowatt sta- tions will be able to span thousands -Instead of hundreds of miles, be cause super-regeneration In cascade will by then make practically all . receiving distances equal. Then the only question the amateur trans-., mitter will have to face will be sig nals over high mountains or pla teaus at short or medium meter wave lengths. Then will come, he says, the need for a universal code language, un derstandable by all nations alike. , This new code language will have to be modern, simple, flexible and have a central "academy" to decide all questions as the coining of new words, spelling, etc. Already Es peranto exists, and for which there is being conducted an active prop aganda. It Is sometimes used, mainly in an experimental way, by radio fans. Then there is "Ido," an improved Esperanta, and "Id'om Neutral." The latter Is said to have several good points but not many adherents. Latin has been reported by sci entists as too difficult for an in ternational auxiliary language. Both Ido and Esperanto are suitable but n-epd careful trial. The G. E. SET A complete Crystal Receiver which can be adapted to Vacuum tube operation. An ideal set for broadcasting reception. MODEL AR 1300 As illustrated... S50 $75 MODEL AA 1400 A detector and two- step amplifier for the above. For the necessary accessories to make this a complete QKC tube station, add VU We have other Sets from $18 up and would be glad to show you. An ideal gift. ELECTRIC CO 75 Sixth St. Stubbs Bldg. RADIO SETS of aH-kinds, made to your order. Complete sets in stock. Large . supply of parts. SMITH-McCOV ELECTRIC CO. 284 Alder St. Main 80ll RADIO A completely equiopitl aeiicHnir and" ..i.in, Ktatlon and exuerwfreUlai ! laboratories. . I t.raduatm are qualified to pan any I soverninent examination. . Day and nlKht clav.es. OKEtiON !NSTlTr, OF TECHNOLOGY. ( 4tb Floor Y. M. C. A. bixtu and Taylor. r n