Radio mirror (Jan-Oct 1923)

12 RADIO DIGEST June 9, 1923 Long Distance Single Tube Receiver Connections Similar to the Ultra Audion The accompanying hook-up is one which has given excellent results. The variable condenser is connected in series with the inductance, plate and filament circuits WORKSHOP KINKS? EARN A DOLLAR— THERE worked aid your fellow are out many little kinks at home that would Radio worker if he only knew about them. There are new hook-ups, new ways of making parts and various unique ways of operating sets that are discovered every day. Radio Digest is very much interested in securing such material. Send them in with full details, including stamped envelope so rejected copy may be returned. The work must be entirely original, not copied. RADIO KINKS DEPARTMENT, Radio Digest 1 23 West Madison St., Chicago. 111. SERIES CONNECTION OF CONDENSER pA\AA/W\A-| .0002.S1 1 riFD 2 MEGOHMS VARIO COUPLER. VAR.COND..001 MFD. Three Honeycomb Coils Used on a Crystal Set The accompanying diagram shows a hook-up which I have recently developed. It is far superior to any other crystal hook-up I have ever tried. In this hookup spider web cr honeycomb coils are used sensitive I thought of the scheme as shown in B. This was better and the relative capacities and number of turns on a 4-inch tube were as follows: .0001 mfd 54 turns .0005 mfd 25 turns .005 mfd 10 turns .006 mfd 9 turns UNIMG COIL somewhat like the ultra audion. I have | heard local stations on a horn with just one tube. In colder weather I have copied ! KFI and KHJ, both 1,900 miles away on ' an aerial 65 feet long and only 20 feet high. After adjustments are made, tuning can be accomplished with either the rotor or condenser. The rotary side of the variable condenser should be connected to the ground to eliminate body capacity. — J. W. Mayfield, Cincinnati. Ohio. FIXED CONDENSER RECEIVING SET Spider Web Coils on Cabinet Ends Spider web. coils are shown mounted on the end of a cabinet. One of the coils is mounted with hinges attached on the cabinet. The other is fastened to the edge of A, -^ B The ■ . . . ■ casting came in just as nearly through this series wave trap as it did through the parallel one except with the .0001 condenser. This would show that a 50-turn honeycomb coil with a 23-plate condenser in series with it would make a splendid wave trap. It would also be much more effective than the parallel or shunt type on account of having more coils or inductance to hold back the waves Side view FR.ONT V1E.UJ V I SECONDARY 90 TURNS a square piece of wood so that the hinges are at right angles to the cabinet. Both of the coils fold against the cabinet and a rubber band fastened to the cabinet slips over a stud on the outer coil and it holds them flat against the cabinet end. This set of coils cost me 45 cents with hinges and they have given me an efficient tuning set. — C. "W. "Woodside, Calgary, Canada. Measuring Condensers Wishing to measure the capacity of some condensers which were unmarked with the capacity when I bought them I happened to think of connecting a tuning coil into a wave trap, as shown in the circuit A. This is a circuit usually recommended for a wave trap. With ten coils on a 4-inch tube it took .00025 mfd. capacity. I next connected in a .0005 mfd. condenser 'when it took two or three coils. As two or three coils was not sufficiently RUBBER. BAND wanted. It is necessary to have one condenser whose capacity is known. Having obtained the constant you can use it to measure an unknown one. N2C = constant (approximately). This formula was used to measure the condensers. N = number of coils. C= capacity. — D. W. Starkey, Chicago, 111. r REFLEX Erla Reflex Transformers DEALERS: SEND FOR LITERATURE ==^ jiijijw: 123 W. M adixon Jt.Chicqqo For Weeks You Have Been Reading of the Superior Advantages of SPIDER WEB COILS (Copyrighted) EUGENE T. TURNEY is the inventor of Spider Web Coils and holds the only patent granted by the U. S. Government. TURNEY COILS are wound by Automatic Machines, on Bakelite Cores, and are taking first place in the Radio Field today. They are 'cheaper and more efficient than Duolateral Coils. PRICES OF SEPARATE COILS S. W. 10, 26 Turns, Enameled Wire, 60c S. W. 15, 36 Turns, Enameled Wire, 65c S. W. 20, 40 Turns, Enameled Wire, 70c Turney's Spider Web Plex Tuner Three Coils Combined Mounted on Bakelite Panel PRIMARY SECONDARY TICKLER Price Complete $450 With 4 Different Hook-ups (3 Tube and 1 Crystal) \t Your Dealers or Direct by Mail. Cash or Money Order (No Stamps or Checks) We Are the SOLE NATIONAL DISTRIBUTORS for Turney's Spider Web Coils TRISTAN SALES CORPORATION No. 1 UNION SQUARE NEW YORK CITY Beginners' Aids To obtain the most out of a newlypurchased receiving set, it is necessary to learn a few rudimentary principles of operation. What to do and what not to do should be memorized. If you have a crystal detector, keep the fingers off the mineral. Handling it leaves a greasy surface and it is more apt to collect dust. It is best to keep it covered and if you must handle the crystal, do so with a pair of tweezers. Don't attempt to find out what is inside of your head receivers. Many poor results can be traced to the fact that the individual was too inquisitive and opened the receivers by unscrewing the caps. In doing so, you will bend the diaphragms and almost surely ruin the phones. The diaphragms are made of very thin metal and are easily bent if handled. You may also injure the winding, as it is wound with wire as fine as hair. If you have purchased a complete set, don't handle it roughly, as you may loosen a connection inside the cabinet. Don't try to change any of the wiring if you are unfamiliar with the working of it. .000s in conjunction with a crystal detector. I had been troubled with interference until I found that this hook-up eliminates it quite well. — Leo Schechter, St. Louis, Mo. Testing for Open Circuit The windings of the amplifying transformers may be tested for open circuits by means of a telephone and a single dry cell. The absence of a click or a very faint click when breaking the circuit indicates that the winding is open. SOMETHING NEW >&vMi//// Shielding Panels of In the shielding of a panel it is only necessarj' to shield the parts of the panel that house the tuning controls, such as the variometer, variocouplers or tuners. The detector and amplifying units do not have to be shielded. In some of the commercial sets the units are shielded separately. There is a separate shield for each variometer, tuner and condenser. A real loud Talk, ing Detector made of "B" Metal. 100% | superior to any crystal. I Puts n e wj life intol your set' Guaranteed for one year. It's the cheapest in the long run. Sold by all live dealers, or can be ordered from the B-Metal Refining Co. 3134 Trumbull Ave. Detroit, Mich. 50c — WILLARD WILLARD RADIO COMPANY Dept. R. D.; 291 Broadway, New York City "The Best for Less" REINARTZ CIRCUIT EVERY PART COMPLETE 1 Bemartz wound coil. 1 tube socket. 1 rheostat. 1 23-plate .0005 MFD. variable condenser. l-13-p)ate .0002o MFD. variable condenser, 3 inductance switches. 16 switch points and nuts. 4 switch stops and nuts, b binding posts. 2 3" dials, 1 variable grid leak, 1 .002 MFD. phone condenser. 23 teet bus bar wire, 1 high-grade panel ALREADY DBILLED AS PER DIAGRAM and complete instructions witcn stops and $10.00 Two-Stage Audio Frequency Amplifier— Parts complete in every detail for this Circuit $11.09 3 Plato 13 Plate 23 Plate 43 Plate CONDENSERS Variable; value, SI. 75 Variable; value, S2.50 Variable; value, $4.50 ...JI.05 ... 1.20 1.35 ... 1.85 13 Plate 23 Plate 43 Plate VERNIER: value, S5.50 VERNIER; value. S6O0... VERNIER; value, S6.50... 3.75 ... 4.00 ... 4.25 VARIOCOVPLEK — Celeron Condensite and Litz Wire Wound Secondary; Value S4..50. Special §2.95 AUDIO FREQUENCY TRANSFORMER — Designed for use with XV. D. 11 Tubes, list, $4.50; price. S2.75 Honeycomb Coils, 50 turns mounted. SO. 95 Honeycomb Coils, 75 turns mounted. 1.00 Double Coil Mountings 2.45 Triple Coil Mountings 3.35 Reinartz Coils and Mounting 1.45 BALL BEARING INDUCTANCE SWITCH — value 75c. special SO. 30 V. T. SOCKETS— Nickeled, brass sleeve, composition base value, SI. 00: special at.. .50 EXTRA SPECIAL— Telephone 3000 Ohms Head sets: S9.00 value: reduced to S3.50 ALUMINUM LOUD SPEAKING HORN— Nickel plated, highly polished; $8.00 list $3.75 FLEWELLING CIRCUIT EVERY PART COMPLETE 2 honeycomb coils, 1 2-coil mounting. 2 coil plugs, 3 .006 condensers, 1 variable grid leak, 1 grid leak, 1 23 -plate .0005 MFD. variable condenser, 1 Vernier rheostat. 1 tube socket, 8 binding posts, 20 feet bus bar wire. 1 high-grade panel ALREADY DRILLED AS PER DIAGRAM. 1 3" dial and the Radio Digest Booklet on Operation and Construction of Circuit a oinumg puais. $11.00 Two-Stage Audio Frequency Amplifier — Parts complete in every detail for this Circuit — $11.00. BEST QUALITY JACKS. Single Circuit; value. 85c; special at $0.30 Double Circuit: value, 90c; special at 45 MULTIPLE POINT INDUCTANCE SWITCH with Knob and Dial (15 Switch Points)... 1.45 LIGHTNING ARRESTERS approved by underwriters TWO-INCH DIALS — Same design— for rheostats and potentiometer: special at S0.25 FILAMENT RH EOSTAT— Condensite base; value. SI. 10; special at 70 FILAMENT RHEOSTAT value. SI.50; special at. with 2'/s" dial; THREE-INCH DIALS— Unbreakable — heat resisting composition — high finish: special.. .90 TELEPHONE PLUGS FRESHMAN VARIABLE RESISTANCE LEAK and MICON CONDENSER Combined .75 A BEAUTIFUL "SALRITE" PENCIL FREE With every order of $12.50 or more. Made of beautiful Mahosarjite Rubber, about five inches long. Equipped with vest pocket clip, 10 extra leads and eraser. Will write liie a ciarui and last a lifetime. Only a limited supply available — so rush your order now. Now is the time to build your own set to take with you on your vacation. We will be glad to offer you any information or advice that you naay require. Just drop us a line. Every article advertised above is guaranteed by the manufacturer and by us — Mail orders filled immediately — transportation PREPAID on all orders of $5-00 or over east of the Mississippi River. All others include postage. UMfl