Radio Digest (Oct 1923-July 1924)

February 2, 1921+ R A J.) I O DIGEST — Illwtratpd Modified Form of a Green Regenerative Circuu Part I — Loud Signals Attuned with Circuit By Myron P. Green THERE have been certain rules emphatically dished out to the Radio public specifically stating that any circuit not accepted and considered "standard" was a "freak." No reason is given why any circuit not acceptable to these experts is considered in this light other than that it doesn't comply with what they call "standard." The fact that it might work much better or more consistently is lost sight of and the moment any circuit is presented that diverges it the least, it is taboo and rubber stamped "freak." This fact might be harmful to the science of Radio were it universal, but I am thankful to say it is not. Radio has improved by leaps and bounds by diligent experimenting on the part of those most interested in this wonderful science, and by those who take nothing for granted. None of these men have any ax to grind; they are workers toward a result that perhaps will make Radio history. Improving' Regeneration Circuit The writer formerly had a standard form of regenerative circuit consisting of two variometers and a variocoupler. This set did all that was claimed for it and I was satisfied until I began to experiment to see if the circuit couldn't be ,sT7AERIAL a: 23PL.COND. I MEGOHM GR.ID LEAK. m *H-H'h -= GROUND The circuit herein shown might be termed "freak" possibly because it differs so much in the placing of the parts from the standard form, but right here I wish to explain how this circuit originated. An Efficient Lead-In The materials necessary for making this lead-in are one porcelain tube, 1% or 2 inches in diameter, such as electricians use in wiring a house; a copper or brass rod, % inch in diameter and 1 inch longer than the tube; two binding posts and a quantity of the compound used to seal dry batteries. Bore a ^4 -inch hole, % inch deep, in any old board and insert the rod therein in a vertical position. Place the porcelain tube over the rod so that the rod extends B1NOINC POST TO SET PORCELAIN TO&E BR./VSS OR. ' COPPM. e.oo TOAERlAl SEALING WAS up through the center. Melt the wax and pour enough of it into the tube to fill it completely. When" the wax has hardened, solder a binding post to each end of the rod and you will have a lead-in free from energy losses. — J. Hovey, Sylvan Beach, N. T. The Best Type of Aerial A single wire of number 14 bare copper, from 40 to 80 feet in length, just as high and straight as it can be erected, with the lead-in coming from one end, and not from the middle, or anywhere near it, makes the best aerial. Insulate the aerial carefully to see that it does not touch anything. _ "MADERA" %3? "CLEARSPEAKERS" No. 804 $15.00 The New Voice of Radio Made from "Madora," an artificial wood, cast In steel dies, under great pressure and heat. Is twice as dense as natural wood. Choiceol 5 styles complete with Baldwin loudspeaker unit, ready for use with any radio set. Wonderful Acoustic Properties resembling a century old violin. Reproduces human voice or music with rare fidelity, preserving the "ovortones" that distinguish each voice or instrument. Order from your Dealer. If he cannot supply you, send us his name and address. AMERICAN ART MACHE CO. 347 West Austin Avenue CHICAGO improved upon. I changed this and changed that, making all manner of combinations with the idea of increasing the tone volume, and I claim that I have done it. Without fear of contradiction I honestly say that the tone volume of this "freak" circuit is far better than that of CARTER Vernier Control Rheostat 6 ohms $1.50 Z0 or 30 ohms 1.75 No scraping. No jerking. i\o friction bearing connections. Phosphor-bronze contact spring. Pig-tail connection insures positive contact. Carter Vernier Control Rheostat gives that close adjustment so essential to successful broadcast reception, where stations operate on wave lengths but a few meters apart. A Carter Vernier Control Rheostat makes your set much more selective. Write for catalog of other Carter Products. r Ahaisatci Phenolic fin ikmauon Product .SHEETS TUBES RODS RADIO PANELS POLISHED BLACK FINISH CUT PERFECTLY SQUARE TO ANY SIZE Vzi THICK /2* PER SO. INCH Vie" THICK 34 < PER SO. INCH %2" THICK 1 * PER SQ. INCH Ye" THICK l&fe* PER SQ. INCH 3/i6" THICK 2* PER SO INCH VA " THICK 2/2* PER SO. INCH 3/8" THICK A< PER SO INCH '/2" THICK 5 VAfi PER SO INCH SEND FOR COMPLETE PRICE LIST PROMPT ATTENTION TO MAIL ORDERS DEALERS PRICES ON APPLICATION STA R R ETT M FG. CO. 519 SOUTH OREEN ST. CHICAGO its standard predecessor, and I have given a fair test to both sets, trying them on same antenna in different localities. For DX work it leaves nothing to be desired. On one tube I have received the following stations loud enough to hear every word clearly and without straining, all of them within a period of twenty days: WEAN, Providence, WDAJ, College Park, R. I. Ga. WCX, Detroit, Mich. WHAS, Louisville, WDAF, Kansas City WDAR, Philadelphia, Pa. WBAK, Harrisburg, Pa. "WBT, Charlotte, N. C. Ky WJAR, Prov., R. I. WLW, Cincinnati, Ohio. WHAZ, Troy. N. Y. "WMAF, Dartmouth, Mass. WCAP, Washington, WSB, Atlanta, Ga. D. C. WBZ, Springfield, Mass. KOP, Detroit, Mich. WMC, Memphis, Tenn. WTAM, Cleveland, Ohio. WOC, Davenport, la. WWDA, Phila., Pa. Columbia Inside Coil Mounting Newer, Neater, Better Here is an inside eoii mounting made for the radio owner who wishes to keep bulky coils out of sight. It is friction geared and fine "vernier" adjustments are possible. Nothing shows outside panel except knob and pointer. Only $6.00 at all good dealers. DEALERS — Besponsible distributors all have Columbia Radio products. It pays to give your customers the best. No other radio products have tbls name — Insist (HI it. ColumbiaPadio ^r I55N.UNION STREET,** CHICAGO WM7A S ^ ^^Which Aerial— ^ 0 Wire or Ribbon? 4^ OUR Aerial is a part ofi your Receiver! Don't blame your set for "**w * unsatisfactory results. Nine times out of 10 the fault is in the Aerial. Try the sensational new TRANSCONTINENTAL "Bibboa" Aerial — adopted by Radio Engineers, broadcasting laboratories, and thousands of enthusiastic radio fans. It's guaranteed to give clearer tone, bigger volume, greater distance, sensitiveness and selectivity or money refunded. 500% better results with the sensational COPPER AERIAL weather proofed! to resist corrosion. Based on scientific principle that broad surface increases receptivity and amplifies the tone. Equally satisfactory with tube or crystal sets. "Twist it! " says FORREST, the famous radio expert. "2 twists per 60 feet catches waves in all directions.' Order from this ad! If your dealer will not supply you promptly. DEALERS and Postagepaidwhencash AGENTS! Write with order, or Kj.sj. u. j or attractive la^od radto^reaP.IUa!l?v1?Se 8™."°" g^T £^<I ACORN RADIO MFG. CO.. &0c^r~Pin.Bt Dopt. 110 1806 S. Racln* Av«., Chicago bmsy. KDKA, Pittsburgh. Pa. WCBD, Zion City, 111. KDOW, S.S. America (at sea) WSAH, Chicago, III. WDAP, Chicago, 111. KYW, Chicago, 111. (Continued WWJ, Detroit, Mich. CFCA, Toronto, Can. WGR. Buffalo, N. Y. WRW, Tarrytown, N. Y. WBAN, Paterson, X. J. WNAQ, Chicago, 111. on page 28) SEND FOR DEALERS CATALOG FREE 48-PAGE Dealers who handle quality products should get our unusually attractive discounts. All high grade standard sets and supplies. All orders shipped on day received. Write TODAY for catalog FEDERAL RADIO COMPANY Distributors ef Standard Radio Sets and Supplies 1900 Harney St OMAHA, NEBRASKA Superior to Honeycomb Coils Pure Inductances «» A no capacity, all inductance winding List Wave Turns Price Length P-201 25 $ .55 100 340 P-Z0Z 35 .59 125 470 P-203 SO .65 170 650 P-204 75 .74 220-960 P-20S 100 .SO 300-1300 P-206 150 1.10 470-1980 Pfanstiehl UltraAudion 95 150 600 Pfanstiehl Reinartz 1.75 150 600 Pfanstiehl Tuning Unit, consisting of 2 Spider Web Coils with mechanism for supremely sensitive adjust *r An ment ^O.VU At all good dealers or direct on receipt of purchase price. PFANSTIEHL RADIO SERVICE CO. Highland Park, 111. Radio Supplies at Cut Prices BATTERY CHARGERS Tungar Type Charger f 9.21 Homchargers 13.25 CONDENSERS Crosley D 1.90 Bremer-Tully Xo. 23 Vernier 3.65 Bremer-Tully No. 43 4.39 17 Plate Standard 1.04 23 Plate Standard 1. 12 23 Plate Vernier 1.98 VARI0C0UPLERS & VARIOMETERS AC Dayton Coupler 5.35 AC Dajton Variometer 4.88 LOUD SPEAKERS Manhattan 19-20 Atlas 17.50 Baldwin Standard 19.25 R3 Magnavox 24.80 Ml Magnavoi 24.80 Western Electric 10-D 39.50 Western Electric Via Att 9.25 Baldwin C Unit 5.2 1 Atlas Unit 9.60 NEUTR0DYNE PARTS Bremer-Tully complete parts for 5 tube 34.90 Air Core Transformers 1.35 Neutrodons 69 TRANSFORMERS Acme Audio 2.76 No. 45 Jefferson Trans 3.j3 No. 41 Jefferson Trans 2.83 Dayton Fan Trans 2.50 KiUark Trans 2.00 Geraco Trans. 3.25 General Kadio Trans 3.41 Amertran Trans. 4.23 PHONES Western Electric 8.50 Baldwin C 8.45 Frost 2.85 SETS Precision Ace 14.95 Crosley VI 21 .25 Crosley XJ 48.75 B. T. Neutrodyne 5 tube 87.50 Write for Agent's Pricv List Always Include Parcel Post and Insurance. VALLEY RADIO SUPPLY CO. 2206A Locust St., ST. LOUIS, MO.