Radio Digest (Oct 1923-July 1924)

RADIO DIGEST — Illustrated March 29, 192k Questions and Answers Split Variometer 5) HP. B Ite rator and think thai no one has soon, the Radio s bitten me. 1 have been buying the corner newssay it looks pretty eomre 1 start thought I'd \rrite. In his articles on the MUoplex hook-up. the -Mystery Man'' speaks of a ;er. with at least 62 turns -:ator and rotor. What does this it mean that the rotor with rlable condenser in series is rate from the stator with a variable r between the grid and ground? the symbol bridged between the battery fixed con'025 and .002° Couldn't a variolar be used instead of a variometer, if the symbol as indicated above is a varik. Of .what capacity must Again, can the new dry cell tube be used arse, these may seem •lestions. but T am asking them use I do not know and want to learn build this Miloplex III. I've already put up my aerial. Have it like this: The roof is north-south and I erected aerial poles on northeast corner and southwest corners. It is 13 feet above the tin roof and 57 feet long, ..ir.ber 12 stranded copper wire, same sect on ship aerials; three spans. PATENT ATTORNEYS PATEXTS. Booklet free. Highest references, results. WATSON E. COLEMAN, Patent er. 6-S4 G Street Washington, D. C. R $5 to $10 m3de dally while taMng r J Lcwest-eost, Simple-to-leam. Fun•9 giving. Personal Badio Instruction. 'jjs First 4 jobs pay instruction cost. Be jSSSj an expert by Marvelous New Method. J|| Pay by installment. Write for details. ttritfii n i T T i i v n iliiirBiH RADIUMITE The New f ltra-Sensitive Beflei Crystal. Can be used in all reflex circuits and crystal sets. Fully guaranteed. Sent prepaid to any part of United States or Canada upon receipt of Money Order. Price 60c each DEALERS! MOUNTED Write for discounts MAURICE SCHWARTZ & S0N 710-712 Broadway Schenectady, N. Y. $3.00 Value for $1.70 postpaid ELECTRIC SOLDERING IRON Fully guaranteed, complete with 6 ft. cord, box of soldering paste and solder. Ruthfred Electric Specialties 799 Oklahoma Ave., MILWAUKEE, WIS. PANELS 7x10.. $0.95 7x18.. $1.65 7x26.. $2. 40 ,xl2.. 1.10 7x21.. L95 7x28.-2.60 7x14.. 1.30 7x24.. 2.25 7x30.. 2.75 0x14.. 1.75 9x18.. 2.25 9x21.. 2.50 12 x 14. . 2.25 12 x 18. . 3.00 12 X 21. . 3.50 ft" thick — Black— Vi" add 25% Send, money order or pay Postman UNION RADIO COMPANY 144 N. Union St, Akron, Ohio Radio Cabinets Makers of Radio Receiving Sets, write us for QUANTITY prices on Wood Cabinets. THE REED MFG. CO SPRINGFIELD, OHIO "Makers of Furniture" CRYSTAL Surface Sensi The Recognized Standard Crystal Rectifier Used All Over the World Hundreds of Thousands of Satisfied Users. Rusonite Has Revolutionized Crystal Radio Reception. 'THE PERFECT SYNTHETIC CRYSTAL' Guaranteed Price mounted 50c Rusonite Catwhisker 14K Gold Supersensitive; will not oxidize Price 25c Order froi alcr or direct from Rusonite Products Corporation 15 Park Row. New York. N. Y. spaced 18 inches apart, the lead-in cominsr down through the skylight from the northeast end of aerial. It is about 40 (Vet long to where 1 want to place my receiver. Everything is doubly insulated with 3-inch round and long corrugated brown insulators, not porcelain. And I've made a dandy ground near end of the w ater pipe that runs to the foot of the yard. Drove four pieces of 1-inch pipe, 6 feet long, down to level of the pipe, scraped them all, clamped them well and soldered all to the water pipe. The ground is clay sand and I've wetted the ground well. Think I'm fixed pretty well here. Do you think the aerial large enough; height from ground is 35 feet. A friend of mine, who built himself an Armstrong set detector and one step of amplification, uses the spider coils, primary, secondary and tickler, with a tj-volt storage battery for the detector. He had a loud speaker on it Sunday night and -we heard concerts at Atlanta, Memphis, Omaha, Seville, Cincinnati, Fort Worth, Dallas and, of course, Washington and New York. He wants me to build PATENTS Procured. Send sketch or model today for examination, prompt report and advice. No charge for preliminary advice. Write for free Booklet and blank form on which to disclose your idea. Highest references. Promptness assured. Clarence A. O'Brien, Registered Patent Lawyer, 200-A Security Bank Building. Directly across the street from Patent Office, Washington, D. C. ULTRADYNE PARTS Transformers, Types A and B (No. 28 and No. 30 D. C. Silk Wire), Each $4.50 Tuning and Oscillating Inductances, L-l and 2, L-3 and 4, Pair $4.58 Complete Set of Parts — Four Transformers and Inductances $22.50 Immediate DeEyery, Complete Instructions, Unconditional Guarantee BRIDGE DISTRIBUTING COMPANY 124 South Ninth Street, Minneapolis, Minn. WHOLESALE ONLY We Specialize in Equipping NEW DEALERS with Complete Radio Stocks MANHATTAN RADIO CO. 112-114 Trinity Place New York City $&$£ * The Talk of the Radio CmttalWlthiScaf World DE-TEX-IT COMPLETE $1.25 A Perfect Fixed Detector Best for Reflex and Crystal Sets POWER— TONE— VOLUME Catwhisker troubles eliminated. Requires no adjustment. Will not burn out. Celerundum Crystal, 50c Celerundum Radio Products Co. 170 Summer Street Standard Radio Corp. Boston Chicago <DIXIE IP you're building a set. you NEED these! The DIXIE Junior Screw Assortment of 100 pieces, all solid brass, nickel plated, and the set of 8 Dixie Initialed Binding: Posts. CIV Each, per box J* SEND FOR BOTH! DIXIE SUPPLY CO. 91 SEVENTH AVE. HEW YORK Junior Screw Assortment Engraved Binding Posts i JEBOILMG $2 .65 ALL TUBES REPAIRED Guaranteed Like New Detectors or Amplifiers . One Amp., 6 Volt Tubes Changed to Vi Amp. Tubes Write Today for Tube C! cular on New and Refilled Tubes American Radio Tube Works Irvington, New Jersey, U. S. A. AGENTS WANTED EVERYWHERE one, but I like the reading of the Miloplex. A. — Your interpretation of a "split variometer" is quite correct as is your method of connections. The conventional symbol of an arrow always signifies a variable unit, in this case a variable grid leak. The CRL grid leak is recommended. When figuring the cost of a switch, contacts and dial, remember they are extra. VT-1 on Dry Cells (06515) AM, Erie, Penna. Is it possible to use 2 VT-1 tubes with dry cell batteries? I want to use them for the audio amplifing stages. How long would dry cell batteries last? Can I use 1 1 FEET LONG Separator Insulator. ^NSJEBB-AERIAfc Substitute for Outside Antenna HO Feet Stranded Copper Wire ay NOT A LOOP BUT A FULL SIZE ANTENNA S>/ **£ ^{pUlieii doubles lone getting far COMPLETE POSTPAID Unaffected by Wind-RamSleetLightning Or $5, ii four set owner's addresses are sent to us. .NTER-STATE SIGNAL CO., DEPT. 1, COLUMBUS, 0 SetS TIRES DIRECT FROM FACTORY i We want an auto owner in each localj.— i \ it; to advertise Armour Cords. You can ijmake Die money and get your own sample I Tires Free, by Beading us orders from friends I and neighbors. No capital or experience need| ed. We deliver & collect direct. Pay you daily. I Most Liberal Tire Guarantee Em Wrrttw I Armour Cords guaranteed by Indemnity Bond lagalnst Blow Out, Wear and Tear. Stone 1 Bruise. Tread Separation. Blistering «ad Bim Cut for 12.500 miles. We are r actual manufacturers. Write today for ' ^ great Special Offer to Agents, and low Factory Prices. Armour Tire & Rubber Co.. DepL 35S-A. Davion 0 2 UV-201A tubes with dry cell batteries? I want to know if they will work with dry cells? According to specifications, they take 5 volts but the filament current is the same as for WD-11. How long would the dry cell batteries last? A. — The life of dry cells used to operate VT-1 tubes, as suggested, would be but a few minutes and the plan is not feasible. TJV-201A tubes can be operated on dry cells. The life of these batteries will be from thirty to fifty hours of service. Blind Wiring TO KNOW where each wire in your set leads, as you build, and when completed, use the TESTLITE. Touch any metal in set with the Hair-Pin, and know instantly the path it follows to a binding post. The Perfect Wire Selector for all electrical purposes. At your dealer or order direct and pay the postman $1.50 on delivery RADIO TEST-LITE CO. S Beekroan Street f New York City ■■—■■-■■ !■■■« * + $25.00 LOUD SPEAKER with Unit and Cord for $9.50 10 inch Bell. Height 24 inches. Colors: Black. Mahogany, Olive Green. On account of the unethical methods pursued by the average Radio dealer, I have decided to sell my product direct to the consumer, thus elimluatinc the factory sales acent, the dlstribjobber and dealer, and saving for the consumer four profits. Sty speaker would sell in the retail store for $25. On. Buy direct and save the difference. My price, $9.50. delivered anywhere In United States or Canada. Orders filled in rotation. EMIL DECLYNE 15 Park Row. Room 612. NEW YORK CITY Send IYI. O. or C. O. O. Dept. B. D., Barclay 6298 Non-para -iri |lV-M N0 PARALLEL WIRES^* V*L SOVERNci QIMLIT -t= r -i 7— r Crystal Reflex Transformer.TC, for use between rube and crystal, is manufactured of the highest dielectric materials and absorption Unreduced to a minimum. The patented NON-PARA-LEL windings reduce internal capacity to nil and results obtained in clearness, volume and distance are exceptional. Jr>e TC can be placed with any good standard tuning parts and form a ono> tube circuit that will operate a loud speaker on nearby stations and also on powerful distant stations. Price, $5.00, from your dealer. If not obtainable from your dealer, we will •mail to you on receipt of $5.00 and your dealer's name and address. NON-PARA-LEL COMPANY 917 KEDZIE AVENUE CHICAGO NEUTRODYNE 5 Tube Sets $40.00 Completely assembled, ready to wire. Incluaes Hazeltine's licensed Neutroformers and other standard guaranteed parts. A set you will be proud to own. Send no money. Pay the postman. H. & O. RADIO CO. 180 West Washington Street, CHICAGO, ILL. Baker Radio Log & Tuner SCIENTIFIC LOG SHEETS, making it easy to tune in any station at will, and often naming the station immediately without waiting for the announcer to call it. Find more stations, all your set is capable of. Send a dollar bill with your name and address and we will mail you 10 BAKER LOG SHEETS with instructions. Money back provided promptly returned in good condition. BAKER BROTHERS 2781 Second Boulevard, Detroit, Mich. RADIO SETS BUILT FREE If you purchase the parts from me at standard prices, Any Type of Set Built Expert workmanship assured. Only the very best parts used. Correspondence invited. HERMAN E. ERICKSON (Associate, Institute tf Radio Engineers) ONE UNION SQUARE— NEW YORK CITY Manufacturers • Who Want Larger Output for Their Product! Well organized, established 20 years, financially sound selling organization— has traveling men covering entire U. S. and Canada, selling only to recognized established jobbers who have a straight line sales policy. Has radio department now handling limited number of high grade products. Can add to its line two or three additional lines. Articles must be in nature of necessities. Only manufacturers having proper financial resources making quality radio will be considered. To the manufacturer qualifying, this organization can put your product on the market in shortest possible time as we are well and favorably known. We can actually relieve you of all sales and advertising problems. Address R. D. 2, Radio Digest, 12S West Madison Street, Chicago. Loud Speaker Pleasing Tone Loud and Clear Speaker, complete with horn, $20.00 Unit only, for a ph. No. 105 $10.00 irfmerica/iS/ectric COMPANY State and S4th Sts., CHICAGO