Radio Digest (Oct 1923-July 1924)

RADIO D I G E S T— Illustrated October 13, 1923 "HELLO" SAYS THIS GROUP OF ZIGZAG LINES The accompanying illustration was reproduced from a motion picture film, but of the ordinary movie theater variety, however. A device known as an oscillograph created this very complex series of xigsag curves. Upon close examination it will be found that the individual vertical streais blend with each other in from left to right. It will be further disclosed that, if the line is traced with the point of a pencil, the pencil will advance from one side of the figure to the other, as it goes up and down in the innumerable peaks and crests. After completing this process, one will conclude that this puzzle of lines represents some form of wave motion. However, that is but the first step toward the solution of the problem. "We will complete the answer by stating that it is a graphical reproduction of the sound waves uttered by the human voice. It is, however, a snapshot of a real, living voice wave. The entire, actual voice movie, as it appears on the screen of the oscillograph at Station TVJZ, New York, obviously could not be presented in its entirety, so one "scene" only is shown in the picture. What Chart Means at Station The Radio movie man who stands watch TWO SUPERSENSITIVE CIRCUITS (Botli Copyrijhted) My Highly Improved Reinartz brings in all lmpor-: Ioils on both coasts and Mexican border. loud, dear and without distortion. We dance to inlw Iron Atlanta received on one loud Baldwin unit. Build one of these wonderful Beta from my blueprint* and specifications, price 50c, or with a perfect and complete double wound spiderweb coll, S3.00 fay mall. No other windings used. Photo of ' my set on a glass panel with every order. This copyrighted circuit is the most successful of any Belnartx modification yet produced, and Is imitated ibe moat. Thousands are in use. My W. O. II Circa, t is especially designed for use with the '"Pickle" tube and brings out the full value of that little tube as no other circuit can. Stations 1000 miles away come in clearly on one tube. This set Is small, complete, portable. For the man who wishes the highest efficiency, this is tie set to build. :'. blueprint and specifications, 54c, or with eosanhte and perfect windings, $3.00. Photo of set win, every order. Sets built from these plans wlil receive all broad under the new laws. Their wa»e length range is from 170 to 800 meters. AUXILIARY TUNER n^w Instrument connected to your present receiving sot with one wire enables you to easily brine in both the long and short wave stations which you earroot get with your present equipment. It also enables you to eliminate that local Interference so you may listen to distant stations. Copyrighted diagram and complete instructions fo: bolldlng and operating this instrument, 50c, or ill parts, including Condenser. Coils, Switches. and Panel. $8.50. Complete Instrument. $15. All gc-ods orenskL These instruments are easy to build, easy to operate. ETerytblug clearly shown. S. A. TWITCHELL 1925 Western Avenue, Minneapolis, Minn. over the diminutive screen of the oscillograph, upon which a beam of light traces an outline of a speaker's voice, consented to allow a "still" photographer to perch his camera near the screen and snap a photo just as an artist was saying "Hello" near the microphone in an adJoining studio. The drawing shows what he got. Connections to the oscillograph are made at the beginning of the long path over which the sound must travel before being shot out from the antenna as Radio waves to listeners. Consequently, if the device Is able to produce a visual record of the vibrations at this point, it may be compared with the final inspection of the finished product of a manufacturing plant, in which an article having passed through stages of development and refinement is thoroughly scanned for defects before being shipped away. Similar in its function of inspecting the quality of transmission, the oscillograph is employed as a checkup instrument at WJZ. By its use, engineers at the station are greatly aided in their efforts to provide perfect modulation and consequent clear reception by the listeners in. Another Columbia Scoop A completely moulded Bakelite Variometer. Green silk pig-tails and wire used throughout._ $4" shaft — no metal bearings used. Design provides for split stators if you need it, permitting any hook-up. A real efficient radio instrument. Complete instructions and hook-ups in each box. Ask your dealer for it. All good dealers stock it. PRICE $5.50 COLUMBIA RADIO CORP. 157 NO. UNION ST. CHICAGO a MAKE PERFECTION rou* SELECTION" Mo. orv, jP,ou.et ofp ea fcev> Benowned for Sound. Bold on a 10-day trial. If not satisfied, money will be refunded. NATHANIEL BALDWIN ■ Phones. Pair with cord and *Q AC REINARTZ We hav* the new Reinartz eon, as approved by Mr. Eelr.a..nz. Complete parts for ttC rifl three-tube set <pOO.UU LIST PRICE $8.00 These Phones are an exceptional value at this low price. Hold on an absolute money back guarantee. LOUD SPEAKERS Morrison $10.00 Pathe 16.50 Music Master 25.75 Magnavox Ml 35 00 Woodenhom 8.50 Perfection Radio Corporation .W^Sa8"^? 6ix New York Retail Stores Add Parcel Post Do Not Send Stamps 208 page complete Radio catalogue free with orders of $5.00 on request. Other-arise prepaid for 25 cents. The oscillograph, while old in principle, is comparatively new in its application to the broadcast station, and makes perfect transmission more easily attainable. -Improved Ground Clamp Equipped with Fahnestock Patent Wire Connectors Easily Attached No Soldering. For Radio Use Only At Your Dealers Fahnestock Electric Co. Long Island City, N. Y. What About It? Isn't it about time to stop experimenting with multiple control circuits and build one that, combining ease of assembly and operation, loudness, clarity and selectivity of signals, as well as beautiful appearance. is excelled by none? THE ELGIN SUPER-RE1NARTZ RADIO RECEIVING SET Embodies all the advantages of the well known Elgin Reinartz (the set which was largely responsible for the popularity of this wonderful circuit) and many others. It is much louder, more selective, requires no storage battery, and can be used with excellent results on a short or loop aerial. It has brought in California stations two thousand miles from Elgin, clearly and without interference on a loud speaker with only one tube, and that while our powerful local station was broadcasting three miles away. Could you ask for more? Write for circular giving one, two and ^three bulb hook-ups of this remarkable circuit. IT IS FREE. ELGIN RADIO SUPPLY CO. 207 East Chicago Street ELGIN, ILLINOIS POSITIVE RESULTS are being obtained by thousands of satisfied users o( the EASTERN COIL SETS for the C0CKADAY CIRCUIT The remarkable features which are making this circuit (4 circuit tunei; more popular each day are its simplicity of construction and control — wonderful selectivity — distance records — clearness and loudness of reception, and the fact that all capacity squealing, interference, etc., are eliminated. Made as per specifications of Mr. Cockaday, using No. 18 wire with D coil bank-wound. COMPLETE ASSEMBLED SET OF B, C AND D COILS. 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Ask your dealer for Federal Standard Head Sets — and accept no substitute. 130 Federal Standard Radio parts offer the radio enthusiast a complete line of guaranteed parts of one quality — the best. ^federal Radio Equipment Jfeoeral Celepfjone ano GTeiesrapf) Company Boston New York San Francisco ISndgeburg, Canada Factory: Buffalo, N. Y Philadelphia iphia Chicago Pittsburgh London, England