OCR Text |
Show Sees Shields and One R F. Stage in Future B Eliminator Is ; Very Useful Part How copper shielding prevents loss In selectivity- - as the sensitivity of a radio set Is increased. Is described by Robert F. Gowen of the Institute of Radio Engineers In a survey of magnetic shielding prepared for the Copper and Brass Research association. Pointing out that the selectivity of a set gets worse as thesensitlvity becomes higher, Mr. Gowen explains that adding stages of amplification to provide Increased sensitivity broadens out the tuning so that when the signals are delivered to de tector tube, there are usually mixed with them signals from other stations operating on nearly the same frequency. This loss In selectivity results from the fact that stages added are usually damped or neutralized In order to prevent oscillation due to inner-stag- e feed back of energy from the coupling between the inductances used. Many schemes are used to prevent this feed back without excessive damping and, according to the survey, when more than two stages of radiofrequency are employed the problea becomes more difficult It becomes necessary to use magnetic shielding to prevent coupling between the Inductances of the set and to prevent the loss in selectivity as the sensitivity Is Increased. Experiments show that Inter-stag- e shielding Is not enough, and Mr. Gowen declares that the day is not far distant when all receivers will be Inclosed in completely shielded copper cases. Otherwise it will not be possible, with broadcast stations working on superpower, for a set in a congested transmitting area to be affected by the desired station alone. Stromberg-Cnrlso- n la cited as one manufacturer who has shielded enough to make It worth while and has need sheet copper for shielding. Indications are that Jbattery leads must be shielded eventually also. "Engineers and manufacturers are now beginning to see that the trend toward the Ideal set .of the future Is to reverse the present practice of building supersensltlve receivers of great number of tubes as these receivers require an excessive amount of power supply and maintenance with elaborate shielding to prevent Intery stage ; oscillation In the deof line new The stages. receivtobuild a Is simple velopment er embodying not more than one stage of highest efficiency and selectivity In a thoroughly shielded copper cabinet The highly and efficient Browning-Drak- e sets are good present-da- y examples of this design. It is safe to assume that eventually the shielded cabinet will Include the power unit (or batteries nntil power units are fully developed) so that there can be no chance of pickup from cables, , employed for connection. radio-frequen- Serves to Harness Usual Electric Lighting Current Device By CHARLES GOLENPAUL There Is nothing renlly complicated about the usual B eliminator. It serves to harness the usual electric lighting current, obtained from the nearest socket or convenience outlet, to the radio receiver. In place of B Just how this Is accombatteries., ' Is .worth knowing by those plished now enjoying a B" eliminator, and by those contemplating the early purchase of such a device. To begin with, the usual alternating current that comes from the socket or convenience outlet cannot be employed for radio purposes. It Is cui-rethat flows first In one direction and then In the other, changing Its direction of flow at the rate of many times per second. Such undecided current, If we may term It such, could not be Introduced In a radio circuit without causing havoc. So It is obvious that alternating current must be straightened out or made to flow In. one direction .only. Through Transformer. The first step Is to pass the alternating current through a transformer which steps up the original voltage to twice or more its potential In order to operate the mechanism that , follows. The current Is still alternating In character, despite passing through . nt te . the transformer. The current from the transformer Is now led to a most ingenious device which we may call an electric turnstile. It Is similar In action to the turnstiles used in. subways and electric railways for the purpose of letting persons pass through In one direction but barring them if they try to pass through in the reverse direction. Such an electric turnstile is called a rectifier. In the usual "B eliminator either the Raytheon or Rectron rectifier Is employed. The former Is a -- radio-frequenc- y radio-frequenc- gaseous conductor tube, without a filament to burn. The Initial current causes a certain breakdown or Ionization of the gas, which establishes a conduction of path for the one-wa- y the alternating current In the case ef the Rectron, a filament. Is employed, and the particles or electrons given off by the heated filament metal establish the one-wa- y bridge for the alternating current. Some B eliminators employ chemical cells which have tho one-wa- y conduction property. Filter Stops Ripples. e Most B" eliminators are rectifiers, which means that the entire alternating current is passed through by means of a double turnwith one gate stile arrangement, thrown open while the other is closed, and vice versa, for greatest efficiency, lluf-wav- e rectifiers present only one turnstile, which Is thrown open only at every other Interval when the alternating current Is flowing momentarily fn the right direction. . Now the carrent that has passed through the electric turnstile or rectifier Is flowing In one direction only. Because of the turnstile action. It toiues in pulses, so that It Is called pulsating direct current. If applied to delicate radio circuits these little pulsator or electric ripples would make their presence known by excessive hum. So the current. must be passed through a filter to Iron out the ripples. The filter consists of two elements, namely, choke coils and filter condensers. The choke colls serve to check the pulsating current, while the filter condensers serve to store the current electrlcaT balance Is A beautiful t truck between chokes and condensers. It Is as though we were employing a dam to control the spring freshets, which would otherwise pour down a valley as uncontrollable floods. The chokes are the dam, while the condensers are the Impounding area or reservoir behind the dam. As a result of the damming action the freshets are converted Into a steady Cow of water throughout the year for Irrigation and other useful purposes. Just as the pulsating current from the B eliminator filter Is converted Into a steady flow of current, quite free from requency full-wav- - Plug-I- n the Coils Short-Wav- e A very convenient and inexpensive colls set of mountings for short-wavcan be made from a few UX tube bases, a UX socket, and a few strips of bakelite. illusoff as cut are bases The tube trated and soldering lugs are soldered to the tops of the prongs. , Then a hole Is drilled In the center of the tube base and it is bolted to the bakelite strip. Care must be taken that the head of the screw does not e. How to Mount Plug-I- n m-Tube Colls in a Socket. Vacuu- project above the surface of the strip, so that It will not come In contact with the coll. This strip Is drilled at the ends and the coll Is bolted to It by another strip ' of the same length. The socket Is mounted on one end of a wider strtp and the primary on the other. The mounting for the primary Is made out of a piece of 4 inch bakelite, supported by a bracket which is made from a piece of sheet brass and a piece of brass tubing. The coil is bolted to It by another strip of the piece of bakelite. Two pieces of . heavy copper wire are fastened tightly into holes In the piece of bakelite. THese are used as terminals for the primary. If a rfubpane! is used the socket and the primary may be mounted directly on the subpanel. Radio News -- - Should Be Tapped Alone y r 4(SX 127. Weitern Newspaper Untun.) Blest b the tongue that speak no 111. Whose words are always true. That keeps the law of kindness still Whatever others do. Blest be the hands that toll to aid. ceaseless , The great worlds need The hands that never are afraid To dJ a kindly deed. fO$TUM set-u- p. . POST TOASTIES Fish, to the table by the direct route from sea, lake or stream Is ? course the Ideal way o! .corn flakes that stay crisp in milk or cream serving them, but modern methods of preserving make.lt possible to obtain canned fish and sea foods of all kinds. A few cans- of your favorite variety will add greatly to your comfort when unexpected company drops In. Fish In the can is more expensive but has very little If any waste and. the labor of preparation is all done. Canned fish roe very nearly equals the fresh and Is admirably adapted to the making of salads and croquettes. Well seasoned roe, brushed with olive oil and baked with a tomato sauce over It Is unusually good. Roe Balad.- - Empty one con of fish roe In a thin cheesecloth bag and drop into boiling water for ten mlnntes. To prepare the water add a bay leaf, a of lemon , Juice, three teaspoonful When cloves ; boll fifteen minutes. cooked drain and set the roe aside to chill, ponring French dressing over it Let stand for an hour and serve with v.v.v.v v.v.-- . So much crisper , these deliciously seasoned corn flakes ; Baked Sardines. flraln one dozen fair sized sardines on paper, then dip them into lemon Juice and cracker crumbs. Bake In the oven for fifteen minutes. Make a sauce of one cupful of tomato and one onion. Cut and toast some whole wheat bread, spread with butter, then lay on the fish. Cut the bread Into strips the width of two fingers. Pojur over the hot sauce and serve. Smoked Salmon on Toast Cut strips of salmon Into very thin slices and broil delicately. Have ready rounds of toasted bread, buttered, lay on the slices of salmon and garnish with hard cooked eggs. Serve with string beans. Few know the value of nuts as food ; they are highly nutritious. A few of some kind or other should be found In every luncheon basket of a dinner a y For the beginning fruit cocktail Is very popular and Use pineapple, most wholesome. grapefruit, oranges, canned peaches or apricots; in fact, almost any good fruit Serve with a thick sugar sirup that has been boiled and cooled, adding lemon Juice und rind. Serve In tall glasses and have the fruit chilled. Timely Tips. A good workman has good tools and takes pride in their care. Utensils in the kitchen should last for years with peeper use. Such things as egg beaters, or any utensils that torn with a crank and have oil in their gearing, should never be put into water up to the unless soiled, gearing then wash quickly with clear hot water and dry thoroughly before putting away. Tins, molds, sheet iron pans and all utensils subject to rust, should he carefully dried before putting away. It is wise to grease lightly with fat unless used at least once a week. Be careful of the bone, wood or d Such should cutlery. never be' dropped into water but washed and rinsed and dried with a soft cloth. Sieves unless used for fat should never be washed with soap ; clean with a brush, using soda instead of soap. Graters if washed as soon as possible (using a vegetable brush), rinsed and dried, will never need soaking. All saucepans should be .as bright and clean outside as Inside. This is not always easy, but If they are never allowed to keep a 6pot, the work, is - Ask for PLEASING. FOODS watercress. Companv- ku 4 -- of Note how the golden flakes crackle as you pour them into white corn, exquisitely soned. Post Toasties have all the bowl. Now add milk or the delicate flavor of the com. cream and taste their crisp flavor Made from the tender hearts sea- - This unequalled flavor is sealed in lasting crispness by the secret toasting process of the Postum Company. Order a pack-ag- e of these refreshing corn flakes from your grocer. and goodness. Ask by name for Post Toasties the corn flakes that stay crisp in milk or cream. They come ready to serve from the red and yellow, wax wrapped package. -- Q 1927, POSTUM COMPANY, When a man compliments a woman she admires his frankness. FOR INC., T. C lac. BATTLE Dress tor Eclipse Year CREEK, MICH. BEST USED TRUCKS In line with the Interest In Europe In the eclipse that Is to be visible W have a large asaertmeat of m there this year, Paris has an as- tracks of various makoo aad alaea. All , tenaa. tronomical gown. It is of soft "blue are baranlM. Cuk or Write for detail or call aad see os. interwhile at and satin, simply cut, THE WHITE COMPANY vals white motifs in the shape of stars are scattered over the skirt and down 25 Soath 3rd Eut, Saif Laka City, Utah. one side of the bodice. From the left shoulder a motif moon peeps at the A buUful complexion the desire --ut ererr woman sun In the middle of the back. end the admiration ot ererr man. KKEMOLA ell produce It for on!r 11.26 netboaunde of women will teetlfy. FREE BOOKLET. Ask Tour dealer C. U. ar CHILDREN CRY CASTORr Especially Prepared for Infanta and Children of All Ages Mother I Fletcher's Castorla has been in nse for over 80 years to relieve babies and children of Constipation, Flatulency, Wind Colic and Diarrhea ; allaying Feverishness arising therefrom, and, by regulating the Stomach and Bowels, aids the assimilation of Food; giving natural sleep without opiates. The genuine bears signature of ' SKINiBLEACH New York Planning to Put Streets on Roofs New Tork dty talks of a roadway to be built on the roofs of buildings from the lower part of the city to Tonkers. Gotham's traffic problem is costing the city a million and a half dollars a day. This elevated highway on the roofs would be a motor-expres- s thoroughfare. The man. living ont of town could motor down to his work without Interference of cross-traffi- c and park his car on the roof of the building In which he makes his living. The improvement would soon pay for Itself. Tart of the plan calls for a series of moving platforms not hard. Dish towels. If rinsed In cold water, for pedestrians, along the second floor, then washed tn hot suds will keep the platforms running from a speed slow enough to step on easily, np to white. 20 an hour, to provide free transButter crumbs by putting them into a dish with melted butter then stir- sit on two new north and south avering until well and evenly' buttered. nues. It all reads like an II. G. Wells These crumbs are much better for any novel, but it may be realized. Capdish using such crumbs than if dry pers Weekly. crumbs are dotted with bits of butter. Like Ghost From Past When working with almonds, either In a letter recently received from pounding them or grinding, add a few drops of rose water to keep them from her daughter Mary, Mrs. Randolph Wlr-slooiling. of Baltimore, Md., learned Bread crumbs are better used for I Mary was greatly enjoying her vacaall foods which are fried than cracker tion, that she was a good girl and crumbs, as the latter soaks fat. would be home soon. Mrs. Winslow Croquettes, meat balls and such appreciated getting the letter, aldishes may be prepared and covered though it had been written SO years with bread crumbs the day' before, ago and Mary now has two children then fry when needed. of her own. After a service of 40 The poorest home may furnish i years on the front porch, the Winslow glass polished to brightness, a pretty-shapefamily mail box gave up the tumbler or a sherbet glass and this letter .when the bottomghost fell Placed on a pretty paper doily, th out so Suet much. plate does not matter a drink will nppeal to the eye befort Not Too Easy Its delicious coolness Is tasted. , What's the hardest job you Boyle Keep candles for use on lee foe a ever had? Doyle Collecting 'easy or burn.clearei two; they will day payments. and, longer. Moisten the brush of the carpet Two German firms are considering sweeper before using. a weekly passenger air service across the Atlantic. 16-ml- le Berry Co., Dept. W, Mb JdlclUatA or write Dr. Are., Chloafo. Scots Honor Betsy Ross Scotland is taking great Interest in the sesquicentennial of the designing of the American flag, which Is to be held in Philadelphia this year. It has been brought ont there that Betsy Ross, the designer of the Stars and Stripes, was a Scotswoman, and many Scotsmen across the water will honor her memory this year. . A silver earring was found in the oldest settlement of Troy, dating back to at least 2500 B. C. It takes a man with a lot of brass to dispose of a gold brick. pearl-handle- If using a fixed crystal as a detector, let It fit Into a pair of clamps rather than attaching It rigidly to the Occasionally, la rest of the order to enjoy the best in reception. It will be necessary to tap the crystal to bring together new, sensitive spots. Two Station for India this tapping Is done while the crysIf two Before the end of the year remains hooked In the circuit, the tal large broadcasting stations In Bombay rest of the set suffers. Some connec In by operation and Calcutta will be tlons may he jarred loose. Tapping the recently licensed Indian Broadthe crystal while removed from it Deto the report casting ompany, clamps obviates thl possLIUty. partment of Commerce states. - CABINET un-salt- hum. The Register Bank. Now the current Issnlng from the filter circuit would be ready for use If Just, the full output voltage were desired. However, it Is seldom thata radio receiver can employ the full output at all times. Generally, there are various kinds of tubes requiring Furthermore, a different voltages. cer'aln minimum load must bo maintained across most filter circuits and tubes to Insure proper and rectifier s safe operation. Hence the filter outreput Is now delivered to a Is of In terms analogy which sistance, syslike a gatehouse of a water-suppltem, In that It distributes the flow of current over different channels. Mounting for OKe KITCHEN For Indigestion, Dyspepsia, etc. Relieves Distress slier Hurried Meals or Oversating. ' Being a gentle laxative, it keeps the digestive tract working normally. 30c & 90c. At all Druggists. C. C. CREEK, Inc. WOODBURY, N. J. W. N. U., Salt Laka City, No. 23-18- 27. KING WALL FINISH Means tastefully decorated and really dean rooms. It leaves no streaks or spots, and irs so easy to apply that anyone can do it. Just mix it with hot water and its ready for use. $1.00 buys enough King Wall Finish the most attractive color combiand the last word in nations sanitation. Those are tho things you get when you decorate with KINO WALL FINISH. Isnt k worth in vestlgadon? Write today for name of nearest dealer and Free Color Chart, showing 19 beau- to decorate an average size room. Write today for FREE Chart. or tiful colors to choose from. nes 1 bWall Finish THE CHICAGO WHITE LEAD BC OIL CO. 13th St. & S. Western Are. Chicago, UL DISTRIBUTOR SALT LAKE GLASS & PAINT CO. SALT LAKE CITY, UTAH Cuticura Talcum is the Ideal Powder Its purity, smoothness and fragrance, combined with antiseptic and prophylactic properties, which help to overcome disagreeable odours, make it an essential toilet requisite. Soap 25e. Ointment Maidttt, M 5 end Me. Talcum ffie. Sold ewrywhere. Catioar Lbarttorle, 3, DBF Cuticura Sha.inR Stick 25. |