Radio Digest (Oct 1923-July 1924)

Record Details:

Something wrong or inaccurate about this page? Let us Know!

Thanks for helping us continually improve the quality of the Lantern search engine for all of our users! We have millions of scanned pages, so user reports are incredibly helpful for us to identify places where we can improve and update the metadata.

Please describe the issue below, and click "Submit" to send your comments to our team! If you'd prefer, you can also send us an email to mhdl@commarts.wisc.edu with your comments.




We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.

Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.

January 12, 10.^4 RADIO 1)1 G !•. ST — Illustrated Three Tube Set Does the Work of Five Special Tuner Reduces Number of Tubes in Set In the endeavor to find the best hook-up •we forget some things that are facts about Eadio. There are very few known circuits, and many hook-ups are really one or the other of the well-known circuits dif WORKSHOP KINKS? EARN A DOLLAR— THERE are many little kinks worked out at home that would aid your fellow Radio worker if only he 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 obtaining 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, 123 W. Madison St., Chicago ierently arranged. If we would give the hook-ups a little careful study before plunging into them, we perhaps would H-H-l-H* know much about them from the circuit they originated from and know what to expect. Almost all circuits in use at present are based on the three fundamental principles for increasing .. the signal strength, that is regeneration, Radio frequency and super-heterodyne. At present one of the popular circuits is tuned Radio frequency. In keeping abreast of the advance of Radio we are forgetting the proved reliable regenerative circuit that in itself possesses Radio frequency and regeneration and has fewer controls to operate as well as parts in the construction. The writer is a neutrodyne and heterodyne fan, but from the view point of the advantages mentioned, a regenerative circuit with a special tuner is described herein that has tapped secondary as a special means of HOW TO WIND AND ASSEMBLE COILS 10TAPS EVERY T" .ulXN. JO TURN 20""IURN 1»TTURN increasing the signal strength and selectivity, and a tickler coil in the plate circuit inductively related to the secondary. Much has been said about doing away with taps and tuning with a condenser. This is all right for a limited wave length, but for extreme variations of wave lengths considerable signal strength as well as selectivity is sacrificed; therefore we will still use taps to balance the inductance. The regenerative circuit, with the tuner herein described, is equal to any two-stage Radio frequency receiver that I have tried for both selectivity and range. It brings in KHJ of Los Angeles on the loud speaker; so, let your own judgment be your guide. The absence of the additional tubes and transformers for Radio frequency and the less number of controls are the appealing features, and for those desiring to construct such a tuner and receiver the hook-up is herewith given with a description of the tuner. Obtain a 4-inch diameter tube, 7 inches long, of bakelite or formica and wind both primary and secondary on it, using number 24 dec. wire. Wind the secondary first by starting %-inch from one end of the tube. This allows space for bolting a base or support for the tuner. Tap this first turn for a lead to the switch. Wind 20 turns and take off another tap, then 15 more turns and leave a %-inch space on the tube, and start winding in the same direction. Take off another tap at the beginning of the winding, then wind 15 more turns and take off another tap; then continue and wind 20 more turns, completing the secondary, which now has 70 turns of wire, or 35 turns on each side of the %-inch space, and is tapped at the first, 20th, 36th, 50th and 70th turns. In leaving space on a tube it is advisable to cut the wire, pass it through a small hole in the tube and solder it on the inside where it crosses the space to the beginning or continuing of the winding. Next, start winding the primary, spaced one inch from the secondary just completed. Wind 7 turns, tapping each turn, then wind 70 more turns, tapping each seventh turn. Drill a %-inch hole through the tube in the center of the %-inch space between the secondary windings and bolt a thin plate over each hole. The plate is to be drilled for the rotor shaft. Drill a %-inch hole through the exact center of a piece of tube that is 3% inches in diameter and 1% inches long. Wind 16 turns of number 26 dec. wire on each side of the holes (connected across the space), beginning as close to the outside edge as possible. You will have 32 turns on the rotor. This rotor is placed inside of the tube where it revolves. For shafts use %-inch brass rod World's BiJlestBatferjBer Hydrometer and \ ^%W j Proof «* Performance "B" Battery FREE V* «— «• Written" Guarantee READ THIS SPECIAL NEW YEAR'S OFFER. THEN ACT! Thousands of Radio Digest Headers will profit by this amazing offer. Tlier will buy the famous 2-year guaranteed World Battery at the lowest price ever auoted. They will get a' hydrometer and a "B" Battery FREE. And they get the best battery built. It is "World" quality tHal makes possible our 2-year ironclad guarantee. It is "World" Quality that makes "World" owners "tell their friends." That's the best proof of performance any product can have. SEND NO MONEY COMPARE THESE PRICES: You need not send a penny. Just clip this ad and Special 200-houi Rechargeable Storage attach your name and address. Tke r R . . ° ifc. battery will be shipped to you the ,, , , ..,_ tsattenes Y/Jb,.. day your order is received. When 2 Volt for WD-1I and 12 Tubes $ 5.00 the battery arrives, inspect it — 4 Volt for UV-199 Tubes : 8.00 read our 2-year guarantee be R v«lf en A~.r» ft <M fore you pay one penny. Con » Vo 60 Amp 8.50 vince yourself you are pro B Volt Amp JU.uu tected from every angle— that 6 Volt 100 Amp 12.50 the World battery price saves 6 Volt 120 Amp 14.50 you 50%. Get the "B" Bat 6 Volt 140 Amp 16.00 tery and hydrometer FREE. , _. . . . . . _ j Order today. 5% Discount for Cash with Order. special S^!Sv World Battery Co., Dept. L, 60 E. Roosevelt Rd., Chicago, 111. New Year's Offer A^> J ' ^ ' _, , Clip and mail this ad VA. ^^m ¥ fi <r»l ^"m ^ -emir with your World bat V\>V %!&/«• W* I MV ^^^ y , tery order and get this ^sjs. ^V^M AVI B. ^LJH. ^^^^. order hydrometer and "B" bat >x\ ▼ ▼ ^k^ * W mr m ^ ^*< ._j__, tery FREE. ^ today. BEARING FOTVL ROTOR. SHAFTS. BETWEEN SECONDMWCOIL or tubing, one .short piece and one long for the dial. Threi th shafts on one end, pass them through the plates on the outside of the 4-inch tube and lock into the rotor with two nuts and washers. Drill a small hole in each rotor shaft for a retaining pin and use a washer and compression coil spring between ■ these pins and the bearing plates on the tube. Solder the outside or end wires of the rotor on the shafts. This may look like a big job, but if description is followed it will not take long to finish it and you will find it worth while. A better tuner cannot be made. The controls should all have vernier adjustments. The audio frequency for this circuit is standard. It can be made in a separate cabinet. — W. L. Friday, Chicago, 111. Grounding Transformer Cores If adjusting the filaments of an amplifier does not stop it from howling, try attaching a wire from the negative terminal of the battery used for lighting the filaments of the tubes to the ground post of the set. Should the howling continue, try grounding the iron cores of the amplifying transformers by attaching a wire to the cores and bringing it to the ground terminal. Tuner Essential with Crystal Receiving Set Tin form of receiving circuit is a CrJ with the an ind with the phones sh>j around tl i r. This hook-up, how is not satiefactory, bcfau.se it i lermtt the operator to tunc out undenals, and therefore Interference is maximum. Either a single or a double circuit tuner Is preferable. The latter allows more selective tuning. POST CARDS A neatly printed post card (or acknowledgment to broadcasting stations your reception of their 2 dozen, 25 cents, postpaid. D. J. Spangler, Elkhart. Ind. evEREady Radio Batteries -they last longer Conspicuous for vitality and endurance — the right batteries by test and proof for every radio use. NATIONAL CARBON CO., Inc. Headquarters jor Radio Battery Information New York San Francisco Canadian National Carbon Co., Limited Factory and Offices: Toronto, Ontario The New WALNART INDUCTANCE SWITCH r Only with positive contacts can you get good reception. Switch points are unsightly and the contacts are poor. A Walnart Inductance Switch, 1-10 points, gives positive contact and better reception. List Price Complete with Dial $125 Bakelite numbered dial shows exact position at all times. i-istPric »i«j WALNART ""\ VARIABLE GRID RESISTANCE Gets the best results from every tube. Cleans up hissing and brings in signals clear and strong. Nothing to wear out, lasts a life time. Both instruments Condensite CeloroN bases — the perfect dielectric insulation. Send for catalog of the Walnart parts. WALNART ElMftilC MFC. CO. Dept. 417, 1249 W. Van Buren St., Chicago, 111. WEIGHS ONLY, 802 A*200,000.°° COMPANY stands squarely back of the guarantee on everu Scientific headset SEND NO MONEY! &5.°vaI£?tnsto Order Today 3.000 ohms by Postcard fWfB and Pay l£&fel Postman KJI on arrival ,„„,. LOUD X?I% SPEAKER •AID UNIT *195 We Guarantee The Scientific Headset to be the greatest value on the market. Try it for five days. If not satisfactory send it back and your* money0 will be refunded immediately. Circular0 on request. Dealers wanted. THE SCIENTIFIC ELECTRIC WORKS 98 Brookline Ave. dept. w. BOSTON, MASS. Agents for New York and Vicinity— AMBASSADOR SALES CO., 74 Cortlandt St., Phone Cortlandt 6296