Radio Digest (Apr 1925-Jan 1926)

RADIO DICES T— Illustrated October 3, 1025 Questions and Answers Amplifier Voltage (14612) PS. Waite Park. Minn. Why is it that I cannot use more than 45 volts of B current on my 4-tube regenerative set? A. — Without more data on the construction of your receiver we cannot advise why the limit to the voltage you can apply is but 45 volts. Send on the circuit and some details as to make of parts etc., and we may be able to help you. Using audio transformers of any ratio, if two stages, or not more than 2 to 1 if three stages, you should be able to put 90 volts on the amplifiers; with any of the resistance coupling kits, this should be feasible also, and 135 volts would be better. Delco Plant as B Power Supply (14602) EB, Evansville, Ind. I would like to have a hook-up for a B eliminator -to use with a farm lighting plant supplying 32 volts D. C. Also, how I might cut down the voltage to six volts to get rid of the A battery? A. — The only possible way you could get B battery power, from such a system would be in the purchase of a 32-volt to 150-volt dynamotor, and then carefully filter tne output with condensers and chokes. Such units are for sale by many concerns, being army material purchased during the war from General Electric company. The other problem is easily solved as you need only connect a wire to the negative end of the 32-volt bank of batteries and tap in after the third cell for the plus 6-volt lead. If the set is some distance from these batteries it may be necessary to tap in after fourth cell to get 8 volts Men Wanted to build radio sets in spare time. Leon Lambert, Wichita, Kansas. *^1* ^^ . 0\t, &4JSVC&SI. \ Hear What YOU Like YOUR OWN Nameand Address Printed Free on Applause Card? Stations gladly put on requested numbers. We print special cards that yet ATTENTION. Applaud your favorites. I Send No Money »" 100-S1.45; 200-$1.95; 300-$2.45. MONEY REFUNDED If Not Delighted. Order Today, duality cards. High grade printing All therage. Ajoyto use. cpriT with 1st older: log for your set. Shows calls, r *^*-**-* cities, wave lengths, dial positions, remarks, etc. Send go money-just pay postman when you get cards. Order NOW ! Radio Printers, Dept. 9417, Marengo, 111. OhetoorUteStmdani Alfred Graham & Co. London, Eng., Patentees CREATED by the originators and oldest makers of loud speakers, The Amplion is supreme for sensitivity, clarity, natural toneand volume. To hear The Amplion— in comparison— is to understand why it is the outstanding favorite of music lovers the world over. Send for booklet and dealers' names. • THE AMPLION CORPORATION OF AMERICA Suite A, 280MadlBOt» Ave., New York Canadian Distributor*,: Burndept of Canada, Ltd., Toronto H (or more still with greater distance) to allow for voltage drop in the long lines to set. A. B. C. RADIO COURSE (Continued from page 19) inductance Lp in order to prevent the direct current plate circuit BKFPB being short circuited by the low resistance coil. The capacity of the condenser S is sufficiently large to offer a low impedance to the alternating current component of the plate current. Another possible t'ombination is given in figure 118, which shows the use of separate plate and grid oscillatory circuits. (Having explained, in successive chapters, the principles of oscillating tube circuits and methods of combining inductance and capacity to form them, Professor Sloreton next week shows a number of practical applications in Radio usage, of these hook-u»~~. — Editor's Note). ANTENNA ERECTION (Continued from page 20) a roof is considered about right, while much more separation then this is desirable from metal covered roofs, steel buildings, trees, and such. Short vs. Long Aerial When utilizing a tree as a support, always remember to insert the insulator Telegraphy — Both Morse and Wireless taught thoroughly. Big salaries. Wonderful opportunities. Expenses low; chance to earn part. School established fifty years. Catalog free. Dodge's Institute, Sixth St., Valparaiso, Ind. Verify Stations Heard Wth New Reception Cards SEND NO MONEY Special card to send stations. Spaces for station, city, wave length, owner, dial settings, your name, your address, date, time and description of program, etc. Stations verify and return. You can file alphabetically. Good grade cards. Quality printing. 125 cards, $1.00. Money REFUNDED If Not DELIGHTED Fay postman after cards arrive. Postpaid if you prefer pay with order. Send order today — NOW. Postal will do. Radio Printers, Dept. 9917, Marengro, 111. r ii i p| RADIO Storage "B" Battery \i vSJ Lasts Indefinitely— Pays for __. Economy and p'rrformanr^ unheard of before. Recharged at a nfjf!f(ribl»j co-t. Approvd and listed U St;irj'Jnrd by tiling ftvlio Au'horltlM, (nrludlnjr Pop. U»-'.\o J*borHV,rfan, Pop. tkl. In.t. Hund* I lib., Is-thX, Inc.. •n<l oth«r lm qot mnt In irlth Solid livhh.r iUm*. an Irmur marm »*»ir,it. aH<] ■n'l Im'i u*. Y.,*j:i hrftvy iflrmn j«r*. H*.*vj, rin<ni/ii'«<. Drw* y^r* tod»yl SEND NO MONEY l&SfePgi"^ igBfiS «rd«r I, rtr'^'4. Ixtra Off«r: 4 b»ll n. i iwj.ll2.J0. feiy .T0r<wm»n mt'rr •xarotalnft b.V'ri.B. 0 I>nf <:«nt ducouot fat tub with of-itr. H.fl roar order now! WORLD BATTERY COMPANY 1219 9o.Waba»h Ave, Dept.76 „ Chicago, UL PricJt: 6-votf. VAArrv 111. :. 1 '■ Ar,.p fUMl UOAmp.ttlAQ. Ml upHppvi with SotidBubtv Com. Announcing a new and very practical battery connector, the Jones Cabelug consists of a five wire coded cable, anchored to an insulated block, cable ends projecting from the block serving as terminals for the set leads. The block is permanently mounted on the panel or sub-panel, allowing the set builder to complete his wiring arrangement, and leaving nothing to connect but the battery ends. No binding posts required. HOWARD B. JONES 618 S. Canal St. CHICAGO World STORAGE BATTERIES !■„)>» DM, M 210 |,| ,.,r.if. Hatter, ' ' '■«" MOLLIFORMER BUNIT replaces BatteriES QI71Mn POP complete description of this power ojcnLf run M B Unlt> thbt you can bullfj in an hour, at moat reasonable cost. Uses the current from the light socket. Excellent for Supers and all TKF Sets — Assures Krcaler Clarity, DX and Volume — Noiseless, no Tubei nor Acids— Utilizes full wave rectification. Guaranteed to Give Complete Satisfaction or Your Money Refunded. PRICE Complete Kit — 60 Cycle Unit Complete Kit — 25 Cycle Unit Kits Include Rectifier-. Parts told separately if desired. DEALERS— Writ* f«r our prepMiuoa. C. E. JACOBS, Sole Mnfr. 2802 Ht. Kedzle Ave. CHICAGO $22.50 24.50 not less then ten feet from the nearest branch. Although this may shorten your aerial quite a bit, keep in mind that a short one away from all obstacles is infinitely more efficient then a long one whose energy is being almost completely lost by absorption, et cetera. A point worth noting here is, that a low, short aerial is more selective and will pick up much less interference then a long, high one. Therefore, the logical thing for those who are fortunate enough to possess such a location to do is, to erect a large antenna for winter use, when the ether is practically static free, and a small one for the summer when there is so much "noise flying around." It might be worth noting here that the connections become corroded from the weather as time goes on, and that he is wise who attempts to combat it. An excellent aid in so doing is to wrap each joint in the antenna proper with waterproof tape and then givs them a coat of varnish or shellac. Thus it can easily be seen that any soot or other substances Make $100 weekly in spare time. Sell what the public wants — long distance radio receiving sets. Two sales weekly pays $100 profit. No big investment, no canvassing. Sharpe of Colorado made $955 in one month. Representatives wanted at once. This plan is sweeping the country — write today before your county is gone. OZARKA, Inc., 128D West Austin Ave., Chicago. Join LOG Club Send No Money —New 64 Page Log FREE First member from each town is appointed president of local chapter — your membership entitles you to: (1) FREE looseleaf 64 pg. log; (2) new revised sheets as changes are made; (3) FREE reception cards to send stations for verification; (4) FREE radio map; (51 latest information; (6) membership certificate, and (7) privilege of writing your club on any subject. The official log holds 504 stations ; shows cull, fcity, wave length, 4 dial settings, remarks, etc.; Tuning suggestions; station list by wave lengths — by states — by staUons, etc. ; owners; Trouble aids; other valuable information. Club sends new sheets without charge as changes are made. Largest radio club. Convenient. Membership limited. Initiation fee and dues to Jan. 1, 1927 only $3. Pay postman $3 plus postage on FREE log, reception cards, etc., when they arrive. Postpaid if vou send $3 with order. MONEY REFUNDED If Not DELIGHTED Enjoy this CLUB. Join Today — NOW. LOG CLUB, 4417, Bedford Bldg\, Chicago which would tend to aecummulate on the wires and eat away the connections — introducing high resistance — will effectively be prevented from doing so. Undoubtedly it is unnecessary to add that every joint in the aerial should be soldered, for no matter how good an unsoldered connection is made, each wire will acquire from weather conditions a thin film of dirt, thereby creating a separation between wires. ' (Having' shown the necessity of care in antenna construction, Mr. Fenwick ' will next take up the various types of outdoor antenna and the construction of eachPortable types are also considered, as Is the directional effect of most aerials. — Editor's Note.) New Perpetual LOG Loose Leaf for Revisions — Radio Map FREE New 64 page log. Corrected sheets may lie secured as changes in calls, wave lengths, owners, etc., occur. Holds 504 stations. Shows call, city, wave lengths, 4 dial settings, remarks, etc. Tuning suggestions. Station list by wave lengths — by states, etc. Ow,icrs. Trouble aids. Other valuable information. So convenient. Worth many times small cost. A joy to use. Only $1. Pay postman after log arrives. Postpaid if pay with order. Money refunded if not delighted. Order today — now. .Radio Printers, Dept. 8417, Marengfo, 111. It's OUT— Complete everlasting ready to run non-acid, non-sulphating 22 y2 -volt rechargeable "B" storage battery, $2.95. Includes chemical. Does not lose its charge standing idle. Special 2-22^ volts (45 volts) $5.25; 90 volts $10.00; 112% volts $12.50; 135 volts $14.75; 157^ volts $16.80. Nearly 3 years sold on a non-red tape, 30-day trial offer, with complete refund if not thoroughly satisfied. Further guaranteed 2 years. Knockdown kits at still greater savings. Complete ready to run "B" battery charger $2.75. Sample cell 35c. Order direct — send no money — simply pay expressman its cost on delivery, or write for my free literature, testimonials and guarantee. .Same day shipments. My large 36-page radio goods catalogue 10c.. B. D. Smith, 31 Washington Ave., Danbury, Conn. RADIO CABINETS Radio or All $3.50 No. 31 Purpose Table . 15 x 31 x29". Substantial, rigid table that can be used for a thousand purposes. Our Radio Cabinets are furnished in the natural wood only. Beautiful color card with instructions for finishing sent with each cabinet. Made of beautifully grained Fir Woo:1. NEAT FIT K. D. CABINETS Made in a variety of sizes >nld knocked down, easily set up. Holes bored for every screw. No other cabinets offer such unus-ual values. Panel 7x 9" 7" deep $1.80 Panel 7x12" 7" deep 2.00 riel, 9" deep. Battery PaneL 7sl4" 7" <!ee[J Hi. <t?irtr/\ Panel 7x16" 7" deep 2.30 4>IU.DU Panel 7xl&" 7" deep 2,40 Additional"'^ «» ft°nt SSSl Trt4TdSS Ho 10x11x18". of panel forms arm rest when open $3.00 extra. No. 37 — panel sizes 7 x 24", 7 x 26" and 7 x 28", Other £ either size $11.50 Panel 7x20" 7" deep 2.70 Panel 7x28" 7" deep 2.80 carried in k. Prices on request. Set up Complete Ready for Finish, Packed One Each in Carton At $5.00 extra our Console Cabinets can be furnished with built-in loud speakers. The tone chambers of our speakers are made of Pyralin and give forth a full resonant tone. No better made; neat, compact, efficient. Illustrated circular on request. RADIO CABINET DEPARTMENT Express Body Corporation 43 Iiake St. Crystal Lake, Illinois Now! SUB-PANEL MOUNTING TYPE They permit a neater assembly, shorteningof leads and concealing of wiring — as in factory built sets. Same ratios — same prices — as standard type Thordarsons. Order direct if dealer cannot supply. Makers of sets costing up to hundreds of dollars each are mighty particular to use only the best transformers. Follow the lead of the leaders— build or replace with Thordarsons. For tho "Best" 45.000 Cycle SupraHclmidvne. "RADIO" and other leadinE publications recommend in highest terms the Thordarson 2-1 ratio transformers. Take no others 1 Unconditionally Guaranteed Thordarson "Super" Audio Frequency Transformers are to be had in three ratios: 2-1, $5; 8H-1, $4; 6-1, $4.50. Thordarson Power Amplifying Transformers arc $13 the pair. Thordarson Interstate Power Amplifying Transformer, $8. Thordarson Autoformers, $5 Each. DAR SuPer AMPLIFYING TRANSFORMERS Standard on the majority of quality sets Write for free hook-up bulletins. THORTJARSON ELECTRIC MANUFACTURING CO. Transformer sperialtsls since )S95 r AND LARGEST EXCLUSIVE 1 -— Chicago, U.S.A.' ' speaaL ■WORLD'S OLDEST AND LARGEST EXCLUSIVE TRANSFORMER MAKERS