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About The Sunday Oregonian. (Portland, Ore.) 1881-current | View Entire Issue (July 9, 1922)
THE SUNDAY OREGONIAN, PORTLAND, JULY 9, , 1923 7 SgJT;E .'.V ML i.fc.:e-t I 1 - LOOAli radio dealers are demon strating successfully the use of the House lighting; system as an antenna for the reception of the radio concerts by the addition of a new device which has appeared on the market. It is a simple ftttle thing- and plugs into the nearest light socket With the use of this device the lighting wires can. be at tached safely to the receiving set and concerts received practically as well as with the usual antenna. Since the beginning of radio in ventors and scientists have racked their trains to find a suitable sub stitute for the antenna. In order to make radio absolutely practical the unsightly outdoor antenna hanging from the chimney tops or crude poles must be eliminated. When General Squlor, head of the United States signal corps, an RADIO QUERIES Editor Radio Waves and Ripples; Will you please describe to me in Sunday's paper a set that I would be able to re ceive aoo miles with? 1 want to make it myself and would like to know what Darts, etc., I would need to get, the best results. , H. L. S., Portland, Or. tOIt consistent radiophone recep tion from 200 miles away and farther you will need what is known as a short-wave regenerative receiver and a two-stage amplifier. The parts for such a set are as fol lows; For the short-wave receiver you will need a vario-codpler. two variometers, one vacuum tube hold er, oue filament rheostat, one grid leak and condenser, one variable condenser, one deteccor tube and a 22 1-2-voIt B battery. For the am plifier you will need two vacuum tube holders, two filament rheostats, two amplifying transformers, two amplifier tubes and a 45-volt B bat tery. A six-volt 100-ampere hour storage battery will be required to light the filaments of the three tubes. Editor Radio Waves and Ripples: 1. Where- is the best place to connect a variable condenser in a set composed of the following: Crystal detector, tuning coil, fixed condenser across the phones and a loading coil? Please publish hook up. '2. Why is it that I can hear all the . local stations plain but K. G. X. ? 3. Give information for making a sending condenser. - 4. Is No. 28 wire all right for winding a loading coil? , - W. T., Portland, Or. 1. Place the variable condenses in series with the aerial circuit or in parallel by shunting it around the tuning coil. This column is too limited in space to publish any , hook-upa. Send a stamped 'and ad dressed envelope and will mail the hook-up to you. 2. Station KGN is using very small power at the present time. 3. The size of the condenser will depend on the amount of power of your coil or transformer. As you do not state the power it will be im possible to give you any data- for the condenser. The data for the construction of a sending condenser will be furnished if you state the power of your coil or transformer. 4. No. 26 will do, but would ad Vise the use of a larger wire, say about No. 22, as the smaller size has too large a resistance to the oscil latory currents. Editor Radio Waves and Ripples: 1. Are the Brandea phones reliable? 2. Will No. 25 double cotton covered copper wire do for the winding of the variometer that you described in your issue of June 11? 3. How far will an uiduotfon coil giv ing a 0-inch spark send? How far, with one giving a 10-inch spark? How far with one giving a 1-meter spark? V. T., Portland. Or. 1. The Brandes are one of the reliable makes in use today. 2. Would not advise the use of smaller wire in winding the de scribed variometer. Smaller wire has too great a resistance to the oscillatory ' currents and would thereby weaken the sigaals. S. The distance certain coil will carry is not measured by the size of the spark. The modern spark transmitting stations use but a comparatively small voltage of perhaps 10,00 to 15.00A volts with a large current. The spark is small in comparison to the induction coils but, because of the large current, travel much farther in the ether than the high voltage and highly damped spark of the Induction coiL Editor Radio Waves and Ripples: 1. Which would he the best to use witlt a crystal set, a varlo-coupler or a variometer ? 2. Is it necessary to use a variable condenser with either one? . What would the capacity of the variable condenser have to be, with such set as described to take on a coming trip in Sunday Oregonian of June 25? Would- a CroBely variable condenser with a capacity of .0005 or .0008 mfd. be all right? It not, how many plates con denser should I use? A FAN, Portland, Or. ' 1. Either the variometer or vario coupler in combination with a crys tal detector will make an efficient set for a short range of perhaps up to 25 miles. . 2. It is not necessary to use 'a variable condenser with such set, but. the addition of one will make the tuning sharper and thereby add 10 ine general etticiency of the set. 3. For short-wava radiophone re ception, the .0005 or .0008 mfd. will do excellently. . , Editor Radio Wave and Ripples: 1. Is there any way I can make an audion tube? If so, how? 2. I have an .aerial 30 feet high and about 100 feet long of No. 2s bare wire. Will this do to receive radiophone from t miles awayr 3. Living 27 miles from Portland: eould I hear The Oregonian with a crys tal set. fixed condenser and a coll made or s.o. D. (J. u. wire having six taps? Will you please send me a hook-up for such set? 4 Could you tell me the parts and cost for an inexpensive audion set? 5.. What is the best kind of phones 10 user . Can I use he ordinary telephone receiver to hear The Oregonian, living 21 nines irom rortiand. A RADIO. FAN, Forest Grove, Or. 1. It is not advisable for any amateur to attempt making vacuum tubes, as they require skillful work and costly machinery in their con struction. It will be much cheaper to buy them. 1. Xo. it wirs la altogether too nounced that he could use the light ing system for an antenna in con nection with his wired wireless" he started a number of rabid radio amateurs to experimenting along dangerous paths. The house light ing system carries a heavy current of electricity in its circuits and is not -a particularly &f e thing for the ' person without the knowledge of electrical Jaws to fopl with. iDespite warnings from electrical inspectors and engineers hundreds of persons literally took their lives in their" hands when they hooked up their sets to the light wires hap hazardly to see -what would happen next. Luckily no fatalities were re ported. Outside of a blown fuse or two and a burnt out tube nothing else happened. The experiments were not successful. If they had studied the subject a little they would have found that the light cir cuit could not toe directly connected to a grounded receiving set without a display of fireworks. The principle of the new device tor connecting a set to the lighting wires 1b 'based on a condenser which Is placed -between the wires and the rest of the set. The gondenser al lows the high frequency oscillatory radio currents to flow across into the receiver, -but holds back the low frequency current of the lighting system. In this manner the use of the lighting wires as an antenna is made safeand practical. It will be but a short time before all outdoor antenna will have been entirely eliminated-and radio made 'wholly practcially for all pirposes and un der all conditions. AND ANSWERS small for an antenna. Do not use anything smaller than No. 14. Also raise the antenna at least 10 feet. 3. Under very favorable condi tions you may hear the Portland, sta tions with a crystal set, but as such conditions are no permanent you will need a vacuum tube detectpr for regular work. 4. An inexpensive audion set 'can be made of a loose-coupler, vacuum tube receptacle, filament switch, de tector tube, "B" battery. "A" battery, fixed condenser, and paid of 2000T ohm phones. A' hook-up of such set will be mailed to you on the receipt of a stamped and addressed en velope. ' 5. A pair of 204W to 3000-ohm re ceivers is necessary for good recep tion of radiophone. 6. No; you will not be able to hear ny distant stations with the ordinary telephone receiver. Editor Radio Waves and Ripples: 1. Please mail me a regenerative hook-up for a single "tube set using the following: ttouble, slide tuning coll, one varimeter, detector tube, grid condenser and leak, A and B batteries. 2. How can I tell when the specific gravity of my V'A" battery ia down 'to 1.1457- ' 8. I have heard that the Bull. Run water on account of its purity can be used In place of distilled water. Is this true ? 4. About how many hours will an ordinary 22-volt B battery? H. Portland, Or. 1. The hook-up has een mailed to you. ' 2. The specific gravity of the battery electrolyte is found by the use of the hydrometer. 3. Tes. 4. The average life of the B bat tery is around 10O0 hours. They usually, however, begin to4weaken after about 700 hours of use. Editor Radio Waves and Ripples: I am i enclosing the diagram of my crystal set. J iT.-Jv anmeLer uiea,in, rlB?i Would I get better results If I took out the double slide tuning coil and put the variometer in its place? Could I receive ooncerts from Seattle with this set? M. 8.. Portland. Or. Tou will get much better results in receiving short waves such as are used in radiophone broadcasting if you take out entirely the double sl'dv: tuning coil and use the vario meter in its place alone. ,The rest of the apparatus is connected- up O. K. It is hardly possible to hear long-distant stations with a crystal set. - Now and then one hears of such a "freak" happening, when ex traordinary receiving conditions pre vailed, but for regular work crystal sets cannot be depended upon for more than 26 miles at the most . Editor Radio Waves and Ripples: I have constructed the variometer de scribed in The Oregonian of June 11. Does the lead from the stator connect to the aerial and the lead from the rotor to the ground wire? 2. Will It be all right to place the condenser directly beneath the vario meter ? 3. Is It necessary to have the two fiber tubes between the stator and the rotor? 4. I have a galvanized iron wire for revolving the rotor. Is this as good ( a copper wire? - , 5. What is tbe range of wave-length 01 mis variometer? 6. How far should the cat whisker post be placed from the crystal cup or noiaer? . . T. Does it make any difference which I side of the crystal the eat whisker Is on. between the crystal and the antenna orJ between the crystal and the phones? 8. llow large a piece 01 copper .should I use to make a lightning switch? V. Could a resonance wave coil be used with this variometer described in The Oregonian of June 11? If se. please give the dimensions and amount of wrie to wind the same. 10. Will any body of iron as large as an automobile serve as a around for a crystal receiver? AN OLD RAIL FAN, ' Timber, tr. - 1. Tes. 2 Yes. . ' V . 3. They are placed between the two coils in order to separate them o that the rotor coil can easily re volve in ana out or tns etator. 4. There will be UUle difference noticed, 6. From 6 to. 600 meters. 6. Several Inches away" will do very well. - " 7. No. - . f : y . 8. Maka the lightning switch as large as possible,, with the blade at least stl inches long and one inch in width. A single-pole double throw type with at least six Inches of throw will make a good light ning switch... .' .... 9. No otbe coll will fte necessary to receive the short waves, as are used for radiophone work. How ever, if you desire to receive the longer waves as are used'-in radio telegraphy, you can plae a loading coil in series, with the aerial circuit. Such coil can easily be made by winding 204 turns- of No. 22 double cotton covered wire on a paper tube for inches in diameter and t inches- long. Every twentieth turn should be tapped and brought to a multiple point switch. Such coil will add- sev eral thousand meteTS of wave length to the aerial circuit. 10. The body of an' automobile will act a a fair ground if it is desired to install a set in the automobile. However, for stationary radio work it will be better to drive an iron stake, to which the ground wire is attached, Into damp earth. Editor Radio Waves and Ripples: 1. Does it maka any difference how far the aerial is located from the re ceiving set? 2. would you please send me a hook- U. S. RADIO EXPERT INVENTS AMPLIFIER WHICH ELIMINATES USE QF BATTERIES P. D. Powell, Employe of Bureau of Standards, Perfects New Device for Wireless, Enabling Operator to Connect Up With-Ordinary Electric Light Socket and Simplify Apparatus. P. D. Powell, radio expert with the nected to the ordinary electric lamp socket, thereby eliminating, A RADIO receiver In which the usual, batteries are eliminated and connection made instead to the ordinary electric lamp socket has been developed by P. D. Powell of the bureau of standards in the de partment of. commerce. The appa ratus is an amplifier, which consti tutes a receiving set when connected with a simple tuner. It may be used with any kind of an antenna. One of the drawbacks to the pres ent type vacuum tube amplifier is the unwieldy and awkward storage battery which is necessary for the lighting of the tube filaments. Mr. Powell, recognizing this, began to experiment along lines which would abolish 'the storage battery in radio use. The new- amplifier eliminates both filament and plate batteries. J The receiving set consists essen up for a vacuum tube set capable of re ceiving at least 250 miles? 3. Please show how a loud speaker could be connected in later on. 4. Xoes your station use continuous waves in sending? t R. S., Nalpee, Wash. 1 For the best results the aerial should be directl over the instru ments. At any rate the antenna should be located so that the an tenna lead is as short as possibl, not any more than 50 or 60 feet at the most. ' 2. The hookup has been mailed to you.- 1 3. The loud speaker Is connected In the cirduit in place of the tele- phone receivers, 4. Yes. All radiophone stations transmit continuous waves. 4Radio Notes. FOREIGN trade news and dls . patches by the radiophone will be another means of informing the American business man of develop ments in foreign fields of industry and commerce if the mnovation to be made by the United States de partment of commerce on July 11 and 12 is to be established as a permanent practice.' This is promised in a bulletin by the department of commerce, .which announces that on the above dates while two large gatherings of busi ness men will be held in Boston and Baltimore and during the two con ventions those present will be con stantly informed by radio of news of foreign markets and trade op portunities received from abroad by the department of commerce. The news will be broadcast by the United States navy radio station at Arling ton, one of the most powerful in the SIMPLE DEVICE AMPLIFIES RECEPTION FOR RADIO SET Little Transformer Example of Phenomena of Electricity Which Takes Small-Voltage Currents and Develops Higher Power. THAT little device known to the radio fans as the "amplifying transformer." which performs no trifling function in strong re production of radio muslo, is an1 ex ample of ' the great phenomena of electricity termed "induction." It is nothing niore than a "step-up" transformer, which takes electrical currents of small voltage and turns them into currents of higher volt age. - The spark coil us.ed on the gas engine is also fn amplifying transformer-which rakes the six volts of the storage battery and turns them into a current of several thousand volts, which will cause a spark to Jump across the points of the epark plugs and bo ignite the gas. How. does a little bit of mechanism perform such a marvel? Look at the : diagram at the head- of this article for a moment and- you can get a general idea of how a trans former works. The square frame work is made of iron or steel. Around each leg of the frame is -wound, a coil, of wire both care fully insulated from each other and also the frame. ' t Liet us assume that we send an alternating current of ten volts through and around the turns of coil No. 1. Each time, the current swings from positive to negative, or back, it sends through the frame, or "core," a strong wave -of mag netism. This magnetism " goes around the core and cuts through tho insulated wire of coil No. 2. A queer thing about magnetism is that, while electricity will not pass thrnne-h certain substances" known as insulators,, magnetism can and" does flow through any substance we know of. ' ... " ' As the magnetism cuts through the insulation of coil No. 2 it causes an actual current of electricity to flow through the turns, of coil No. 2, although this. wire has no electrical connection with coil No. 2. We say that this second, current has been "induced" by the first, and the CsW I1 (tsC5w fcnrean of standards, demonstrating; tially of an amplifier with minor auxiliary parts. This is described In a paper which haS been prepared and will be published by the bureau of standards about the fiTst of May and sold et 5 cents a copy. A few details of tho amplifier, which util izes 60-cycle current supply for both filaments and plates of the, electron tubes, are as 'follows: This amplifier has three radio-frequency stages, and uses a crystal detector. The 60-cycle current when used in an ordinary amplifier circuit Intro-" duces & strong 60-cycle note Which offers serious interference. This has been practically eliminated by balancing resistances, grid con densers and special grid leaks of comparative low resistance; tele phone transformer in the output circuit, and crystal detector, instead of election tube detector. In the final form of the amplifier, there is world, time of broadcasting wilr be 3 P. M.,' eastern time, on the two days, making the time about mid night in California. The wavelength will be 2650 meters. '. . ' m Although much has been said and written about the remarkable filters employed' by the telephone linea and be advanced radio workers forep separation of the telephone and telegraph messages, it has re mained for Dr. Frank B. Jew ett, chief engineer of the Western Electric company, to demonstrate how the filter permits of transmit ting' radio telephone and telegraph messages simultaneously, and of separating these messages at the re ceiving end, at a recent meeting oft the American Institute of Electrical Engineers, the Scientifio American says:- '- ' The present electrical filter is the invention of Dr. G. A. Campbell, a telephone engineer, and makes it possible to separate the various fre "quencies at which the individual Ltelephone and telegraph messages are carried. The detected electrical 'current in a radio receiving set is passed through the filter which sep arates the frequencies of the tele graph message from those of tele phone. 1- The filter differs materially from the ordinary tuned circuits familiar to the radio enthusiasts, -since it separates not single frequencies, but bands of frequencies of any prede termined width. The filter makes it possible to separate the band ef frequencies comprising the telephone message from the band comprising the telegraph message. It can also separate one telephone message from another. . , A dynamo, the revolving center of which weighs several tons and spins CO Sketch of amplifying transformer, giving rough Idea of how a cur. rent of 10 volts la increased to 100 volts. process is what we call "induction.' If the number of turns in the sec ond coil is the same as in the first coil the second coil (will have ap proximately the same voltage as the first. If the second coil has twice the number -of turns, the current will have twice the (voltage of the first, and so on. - " The amplifying transformer In radio work have five orf six times the number of turns in fhe second coil as they have in the first. There fore the output of the transformer will be: in voltage five or six times the input. However, as the voltage is Increased in the transformer, soj is the amperage or amount of cur rent decreased in proportion. While the voltage in the second coif of the transformer is five or six times that of the first, the amount of current will be one-fifth or one-sixth of that in the first. As voltage is what la required mainly, in order to' actuate the hdiaphgrams of a telephone receiver. this loss of chrrent in stepping up the. voltage is eX little. Importance. CoifJfaf JOTurtrs I 1. U--- P i hift new amplifier, which can be con all present batteries. only a slight residual hum which is not objectionable. '- The amplification obtained -with s. c supply was as good as that obtained with the same amplifier used with d. c. supply. The com plete unit is light, compact and portable., For the reception of damped waves, the amplifier as constructed" operated most satisfac torily for wave lengths from 200 to 750 meters. This range was deter mined by the Working range of the radio-frequency transformers used. By nsing suitable radio-frequency transformers, it Is expected that the amplifier will be effective for the reception of damped waves and undamped waves as long as 10,000 meters. For the reception of un damped waves a separate hetero dyne should be employed. The paper gives circuit diagrams and states the Values of the condensers, re sistors and inductors used. at a peripheral speed of several miles a minute, and which produces 27,000 alterations in current every second; is one .of the new develop ments in long-distance radio com munication and marks the sur mounting of such mechanical dif ficulties as have seldom been over corn, v The machine is the invention of E. F. W. Alexanderson, formerly consulting engineer of the General Electric company and now chief en gineer of the Radio Corporation of America. The output of the Alexan- ........ vuiui. . " derson alternator is fed directly to the aeriaL The mechanical difficulties over come 1n the design of the enormous dynamo, which has an output of 200 kilowatts, were so stupendous that the layman can scarcely ap preciate them. The core of the dyn amo, weighing several tons, had to be mounted so that it could be re volved at a speed of 2-0.-0-00 revolu tions every minute, and the bearings had to be adjusted and the core balanced so that it would not move even so small a distance as one millimeter while it was spinning. The outside edge of the core, turn ing at 20.000 revolutions per min ute, attained a speed of several miles a minute, which exerted a great force. The rules for amateurs for keep ing away from light and power wires cannot be made too impres sive. Accidents and deaths, caused by the careless or heedless string ing of wires, are being reported. "Safety First" should be the slogan of every radio fan. Contact with, or even close proximity Ao, any other wires than your own should ve avoided; this is the only safe way. Better over-p"rotection than a death in the family. One death through carelessness or ignorance in the in stallation of radio does more harm to the industry than all the. rules the underwriters might promulgate in five years. The practice of radio in itself is perfectly safe. Danger is only- pres ent in outside . agencies and then only through heedlessness or igno rance in tbe installation of radio does more harm to the industry than all the rules the underwriters might promulgaWs in five years. The practice of' radio in itself is perfectly safe. Danger is only pres ent in outside agencies and then only through heedlessness or igno rance of first principles. Extraordinary possibilities unfold themselves as the result of Major Edwin H. Armstrong's recently an nounced super-regenerative circuit. If, as its inventor claims, it will amplify the ordinary receiving1 set 100,000 times, and thus dispense with all necessity for an ayial, it is like ly to have as great an effect on re ception as his famous "feed-back circuit" had on' transmission, to which it ia now considered Indis pensable. In demonstration Major . Arm strong, proved that a signal which could barely be heard by the ordi nary regenerative set equipped with an antenna at the most critical zero point, could be heard all over the room with the new circuit. Among the benefits claimed by tha inventor for his super-regenerative receiver is one which will be greatly appreciated by amat teurs particularly namely the fact that it will throw open the range of wave lengths 200 meters to effective reception by the ordinary set. One largely undeveloped field of radio during the past has been the shore wave lengths and their satisfactory use will not only encourage the ama teur to further effort, but also con tribute toward cutting down the cost of broadcasting at some early day ii the future. .. Portland radio fans will have an other broadcasting station on the Pacific coast which they may hear in the near future when a powerful station Is installed on the campus of the Washington State Agricultu ral college at Pullman. It is ex pected, that the station of 500-watt power, will be ready for operation when the fall term opens in Sep tember. ' Appropriations of funds anjount- ing to $1200 have been voted by the students, the alumni association and, the various departments of the col lege. This will be supplemented by 1 4808 voted by the Pullman commer cial club. Some of the equipment will be ordered at once and the rest as rapidly as possible, accord ing to H. Y. Carpenter, dean of the college of engineering, who wltn Homer 3. Dana, special experimental engineers of the college, and Harold Vance, president of the All-Engineers' club, is in i charge of the in stallation of 'the station. - It is pointed out that more than 36,000 reserving sets are in operation in Washington and .Qregon, while ther- station will be of sufficient power to -reach all of the western states. Glee lub concerts, lectures and news service will be broadcast from the new station. . . -. ' Increased public interest in radio has caused dealers and others handling radio equipment to request the establishment by the bureau of standards of a seriest. of tests for apparatus. Such a. standard has been agreed upon, ,and will be put In force as soon as practicable. This is ac cording to a bulletin from the United Statis department of commerce. The tests outlined will include ex amination as to materials and work manship of construct'ion, mechani cal and electrical deslsra. simplicity Of adjustment, ruggedness, sensitiv- ity, sharpness of tuning, wave length range and"faithfulness of re production In radio telephone re ception. It was proposed to the bureau or standards that all manufacturers of radio instruments be required to mark them indicating the receiving radius of the equipment under Vari ous atmospheric conaitions. ' It was pointed out by experts of the bu reau, however, this would be Impos sible owing to the large number of factors which enter into the determi nation of the range over which sig nals can be received by a given set. Electricians Create New, Keener Demand for Mica. Many at I.arjre Supply Manufac turing Companies Said te Keen Up Own Mines in Order te Have Plenty. WASHTftGTON,' D. C, July 8. Do jrou remember how Vou used to sit before the old bar rel stove in the parlor, or before that "new fangled" latrobe, watch ing the glow of the cheery winter fire through the "isinglass" win dows? You may think that since the basement furnace has generally- supplanted the troublesome pesky things, the producers of "isinglass" must have long since gone bank rupt; but there's more demand for it now than ever before, says the United States bureau of mines. Anyway, It was not isinglass at all in the front of the stove. Had it been, it would have lasted as long as paper, for isinglass is made of the air bladders of certain fish and is a soluble combustible sub stance. What really was in the stove windows was mica, one of the oddest of natural substances, and which is now one of the greatest boons in the electrical industry as a perfect insulator. So important is.jrhca in electrical goods, it .is declared, that many of the larger electrical supply manufacturing companies own . and operate their own mica mines. I iuicit, eaya Liie uuicau, iuuiuucd i group of several minerals charac Mica, says the bureau,- includes a terized by a perfect basal cleavage by virtue of which they may be split into exceedingly thin plates. How often as a youngster, did you jnake wonderful finds of "gold" or "silver" among the rock deposits near the homestead? Of course, the dreams of wealth vanished when you found the silvery or golden flakes were only mica. Such mica has no commercial value, it is only when it occurs In large deposits where It appears in "books" fairly free from defects, varying in width and length from a few inches to feet and up to six inches or more in thickness, it is of value. Of the several varieties of the mineral, only two are of commercial value, the "muscovite," or white mica, and the "phlogopite" or am ber. India, Canada and the United States are the chief producers. Mica possesses a combination of special qualities -which is found in i no other substance, consequently no satisfactory substitute has been found. Chief among these quali ties are elasticity, toughness, flexi bility, transparency, ability to with- j stand excessive heat and sudden changes of temperature, high dielec trio strength, cleavability and re sistance to decomposition. An important use of electrical mica is for inter-leaving between the copper segments of commuta tors. Thin films are used in vast numbers in condensers, for magne tos and in wireless apparatus. As sheets in greatly diversified shapes, or as washers and tubes nvica is used extensively as an insulator in dynamos and in various appliances, in fuse boxes, sockets, insulators, electric heaters, flatirons, , tele phones, etc. As a heat-resisting, transparent medium, sheet mica is still used in furnace sight holes, for heat screens, lamp chimneys, canopies and shades, particularly for gas mantles, alsa for military Tanterns and lantern slides. Its ability to withstand strains and shocks, combined with its trans parency, has led to wide use in mo tor goggles, spectacles, divers' helmets, smoke helmets, compass cards, gage fr6nts and In windows subject to shock, such as on the con ning towers of battleships. Owing to the resonance of mica circular sheets of high-grade mus covite are used extensively In pho nographs as Bound-producing de vices. Such sheets are also used in other sound-detecting devices, such as the submarine detectorB. The brilliatncy of its reflecting surfaces gives the mineral a wide use as a decoration, nptably as Christmas tree "snow." Coarse ground mica is also used for orna mentation of pottery, lamps, cur tains, cloth, and in India in deo ratin gthe temples. An unusual use for the ground product, which, says the bureau of mines, "fortunately has not extend ed outside India," is in medicinal preparations and found dressings. The recent development of wine uses for the ground product has opened a wide field for the utiliza tion ef waste and scraps, and saved the industry nfuch expense. The more impure and coarser types are used as a eating to prevent tar roof ing from sticking when rolled; 'purer and finer grades are used in paints, ornamental tiles and con crete. A mixture of ground' mica and powdered aluminum is said to make a rust-preventing paint of good quality. On account of -its heat-resisting quality it is used extensively in railrAd car axle packing, in pipe and boiler coverings, in fireproof paints and even in rubber tires. Ground mica is also used in anneal ing steel, as an absorbent, for nitro- glycerin, jo, the manufacture of cer- WORN-OUT PARTS ARE USED TO MAKE GOOD RADIO SET Castle Rock, Wash, Invalid Converts Discarded Machinery Into Perfectly Good Receiving Station. ;i I sit fp-im) v i a SET CONSTRUCTED BY AN EXAMPLE" of what the radio amateur can do with sundry electrical apparatus which has been thrown away as unfit for longer use, is shown by the com plete and efficient receiving set constructed by Ellsworth Price of Castle Rock, Wash., a short time ago. At a small cost. Price bought a lot of broken down electrical ma chinery and made a complete re ceiving set from the parts. The set is a short wave regenerative 01 me single circuit type as described in several issues of The Sunday Ore tain explosives, as a component in roofing, as a filler, in rubber and other products, in calico printing and as tire power. The purest and finer powder is used for wallpaper decorations, as a lubricant for wood bearings and mixed with oil as a lubricant for metal bearings. It has been found that mica may also be used success fully as a flux in ceramic wares. Serial 2357, "Mica," by Oliver Bowleg, mineral technologist, is prepared for general information on mica, and may be obtained from the bureau of mines at Washington. , Radio Records Shattered on Moving Train. . " AstoniHhing Performance '"Made on Cars Carrying Shriners. ALL 'transcontinental radio rec ords were shattered by . the wireless-equipped Shriner train of 12 cars carrying the Syrian temple delegation from Cincinnati, O., which was recently handled by the Southern Pacific A long-distance receiving record of 2000 miles for radiophone was established, as well as a 3000-mile record for telegraph reception while in motion. Aerials were constructed eight inches above the roof of one of the forward cars and were 160 feet in total length. A rail . ground was used. The receiving equipment in cluded honeycomb coils and a two step audio frequency amplifier. The train left Cincinnati in radio touch with both coasts. At Denver music programmes were cbpled from the big radio stations at Pittsburg and Chicago. At Colorado Springs the Cincinnati station was heard. The long-distance record was' made at Santa Barbara, when the radio, while the train was in motion picked up the United States govern- TAKE A WIRELESS SET With you on your va cation. Hear the Portland broadcast ing on your entire trip. Complete sets or all the parts. See the new Colin B. Ken nedy set operating in our display 'room. ELECTRIC CO 75 6th,' Portland Operating K. Q. Y." RADIO FREQUENCY! INCREASE VOUR EFFICIENCY 50 PER CENT Cut down your static. Complete parts for one-stage (J1 f pTA radio frequency amplifier, with tubes, panel, etc. . . ,f !UwU HAW)CK 102 Park St. Radio V "siw&s ELLSWORTH PRICE. gonian a month or so ago. Price writes that the set is working excellently and .he wouldn't trade it for the best manufactured outfit. The Portland stations are heard by Price, according to his letter, both during the day and night, while several California stations have been heard often. Price is an invalid and derives a great deal of comfort from his home-made set. He is now plan ning the addition, of a two-stage amplifier and a magnavox in order to entertain the- town folks of Castle Rock. He lives about 70 miles from Portland. ment station NSS at Annapolis, SOOO miles away. This is claimed to be a record for daylight reception under any conditions and an aston ishing record on two steps of ampli fication from a moving train. Sisters All Imaginary. Little Ethel was an only child, and" one day when the minister called she was told to entertain him in the parlor until her mother could see him. A few minutes later the moth er, on her way downstairs, heard the visitor ask Ethel how many brothers and sisters she had, and, to her surprise and consternation, the little miss answered, "seven." Al though somewhat perturbed,, the mother made no comment upon the remark of her little daughter, but sent her out to play. After 'the minister had left, the child was taken" to task and asked why she had said there were seven children. Ethel replied: "Because I didn't want him to know that you were so poor that 'you didn't have but one child." CLAPP EASTHAM Regenerative Receiver, Detector and Two Step in Cabinet $86.00 The New Antennella eliminates the use of an antenna. Price $2.00 SHIP OWNERS' RADIO SERVICE 310 Oak Street . Near Sixth, Portland, Or. E.L. Knight & Co. RADIO ENGINEERS 440 Washington St., Near 12th. Broadway 0145. Let us help you build your set. Our services are free. We Carry a Complete Stock f All Radio Parts. Concert Every Saturday Night. "WIGHT MAKES DAY THE ELECTRIC WAT" Rotcky Mountain Crystals More sensitive than Galena-' Each Crystal Tone Tested Mounted 85c, i'nmoiinted 20c, postpaid Manufacturers, Jobbers, Dealew, Clubs apply for special trade prices. Rocky Mountain Radio Products, Inc. 9 CHURCH ST., EV YORK, N. 1 SPECIAL Three DePorest Crystal Sets With Brnndea Head l'hones, Kegrulnr Values $25 Mow $21. Radio Service Bureau Gawco Bldg., Portland, Or. A complete RADIO SET $14.50 We, y have all the oiakfn's. . Order bv Mail. CHOWS HARDWARE CO. 147 Fourth Street & WATSON Service. Portland, Or.