Radio Digest (July 1924-Apr 1925)

18 RADIO DIGEST -Illustrated August 16, 1924 Questions and Answers Wave Lengths (06348) E. S.. Rochester, N. Y. Why is it that here in Rochester, where they have reduced the wave length in Radiocasting, most crystal sets cannot get down far enough on coil to get good reception? Is it the shorter the wave the less wire on the coil and vice versa? Will you tell me the proper way to tune In a Westinghouse radiola? Am using a peanut tube having a wave and tickler dial. In your paper of December 8 you show inghouse distributor in your city for the information requested. A peanut tube can be employed, generally speaking, in any standard circuit, which includes that of your inquiry. We recommend a U\ -201A tube, operating on dry cells, as desirable and affording better results than either the WD-11 or UV-199 tubes. The Margo tube is a two-element type and can be substituted advantageously for a crystal detector. USE OF FARM LIGHTING PLANT Being a reader of your valuable paper and taking notice of article in Q. & A. from 9221, T. R. S., Mauraee, Ohio, reminds me of my experience using 32volt farm lighting batteries about two years ago, as a result of which I lost four tubes at different times until I got a regular 6-volt A battery. Tour reply to this is correct so far as it goes, but you should have added. Do not attempt to use this battery system for any other purpose while connected to Radio. To study the accompanying sketch you can see it involves quite a complicated circuit by varying resistances on 32-volt line as well as the 6-volt line. When the resistance between the plates of the three cells (6 volts), is greater than the resistance of the h|#h¥h'H-hI'I"» ev| 26 VO t-T s 1 RADIO "* HOUSE LIGHTS Radio tubes current it is then reversed through — side of Radio circuit making it + side with 26-volt pressure, less 6 volts to neutralize the six cut out. With an ampere flow varying with resistance on regular lighting circuit. — F. C. Bradley, Union, Miss. (By inserting a fuse at the point X the possibility mentioned will be eliminated. — Editor's note.) a hook-up of single-tube selective longdistance Simplex. Will this operate with a peanut tube? If not, what tube shall I use? The Aug. 25 number of Radio Digest 6hows a Margo 1%-volt tube sold by Modell's; could you use same on crystal set instead of crystal and get better results? A. — Wave length depends upon inductance and capacity, consequently fewer turns are used on coil for reception on lower wave lengths. It is recommended that your present coil be rewound with heavier wire to overcome limitations cited. Tuning procedure accompanies manufactured sets, and we refer you to the West PATENT ATTORNEYS PATENTS. Booklet free. Highest references. Best results. WATSON E. COLEMAN, Patent Lawyer, 644 G Street, Washington, D. C. "CRYSTAL Sets Tested 600 Miles." You can now get a genuine Lambert Long Distance Crystal Radio Set for only $4.98. Particulars free. Leon Lambert, 501 Volutsia, Wichita, Kansas. Don't You Get #■%£ ^ -^ <B °' only hearing LOCAL r£|]l stations on your Crystal • •• "-1 ■■ Set? There's rausio on your aerial every night from stations f ar'away. If you. want to'heari t without buying a tube aet, WRITE ME TODAY. LEON LAMBERT 501 South Volutsia Wichita, Kansas ON ONE TUBE Broadcasting from Atlantic Coast, Mexico, Hawaii, Canada and Cuba heard in California by user3 of CROSS COUNTRY CIRCUIT. Range due to simplicity of set and only one tuning control. Easily and cheaply built by any novice. Dry cell tubes may be used. All Instructions, blue print panel layout, assembly photo, etc. Postpaid 25c. Stamps accepted. VESCO RADIO CO. BX D-117 OAKLAND, CAT.. 41 1 B-JtfFtJcKI vM/J&///^///^///MW//j Insured Free — all packages amounting to $3.50 and over. BATTERY CHARGERS Tungar Chargers with bulb $14.50 Gold Seal Home Chargers 13.22 SETS Crosley 51 „.„ _ „„ $14.00 Crosley Trlrdyne 48.75 LOUD SPEAKERS Ml and R3 Magnavox $24.50 M4 Magnavox _ _ 18.75 Western Electric IOD 39.50 Federal 6.00 Western Electric Vic. Att _. 9.25 VALLEY RADIO SUPPLY CO. 2206a Locust St. ST. LOUIS, MO, Write for Agent's Confidential Price List. Always include Parcel Post. Neutrodyne Limitations (8688) GCC, Franklin, 111. I recently built a 5-tube Fada neutrodyne set and don't believe it works properly. I have checked the wiring \»ry carefully and cannot find anything wrong. It is not near as selective as my 3-tube Reinartz but is louder and more quiet. I cannot get WGR or KGO at all when KDKA is broadcasting or WLW very good. Even WFAA and WOC cannot be separated entirely. My aerial is 70 feet long FREE — Log Book with each purchase FACTORY GUARANTEED MDSE. BY MAIL Genuine New Radiotron or Cunningham Tubes UV-199— 200— 201A— WD-11— 12 (fro no C299— 300— 301A— Cll— 12 «pO .I/O Fresh Burgess or Eveready "B" Batteries — 22VZ Volt large size $1.68—45 Volt $5.00 size $3.33 Write for Free new Complete Catalogue STONE ELECTRIC CO., 714 Pine St., .St. Louis, Mo. AM Mdse. F.O.B. St. Louis, Mo. Oept. D WHOLESALE ONLY!! If you are contemplating going into the RADIO BUSINESS SEND FOR OUR NEW ILLUSTRATED CATALOG, WITH BARGAIN PRICES MANHATTAN RADIO CO. 112 Trinity PL New York City Bankrupt Stock Cunningham Regenerative one tube long range sets $9.00 Each Formerly sold at $32.50 No Circulars. Order from This Ad. This set with tube, phones, all batteries and aerial complete, tfJOl f\{\ ready to use, for *A1,W Prepaid while they last". S. A. TWITCHELL 1925 Western Av., Minneapolis, Minn. PRE-AMPLIFIER Registered Makes Summer Radio Practical THE TWITCHELL PRE-AMPLIFIER Is a powerful Radio Frequency Amplifier attachable to any receiving set. It brings In many distant stations which you cannot bear without it. Iirlngs in with tremendous volume those you now hear only faintly. Makes your set selective. Prevents re-radiatlon. Price complete with tube $25.00 Shipped Prepaid S. A. TWITCHELL 1925 Western Ave. MINNEAPOLIS. MINN. I am using 90 volts on and lead-in about 20 feet. 201-A and 200 tube with the amplifiers. A.— We have carefully noted the limitations encountered In operation of your neutrodyne receiver and while It is evidenced that you are not experiencing Its full effectiveness the details offered are Insufficient to isolate the factor which Is acting as a deterrent. Admittedly the circuit is imminantly selective and quiet In operation, under favorable construction, and superior to a 3-tube Reinartz circuit by virtue of the principles Involved. Few builders of the neutrodyne receiver give adequate attention to the important feature of avoiding electromagnetic coupling between the neutroformers. The resulting feedback through the colls Is always too great to be balanced out by the minute capacities of the neutrodns. The neutroformers must be positioned with relation to each other at an angle to prohibit Interaction between their fields. Wave Traps (08001) HDH, Kingston, Ont. Having read your article on "Wave Traps" on page 14 of your issue of February 23d, please advise me if they are potent against local spark coil interference. PATENTS Procured. Send sketch or model today for examination, prompt report and advice. No charge for preliminary advice. Write for free booklets "How to Obtain a Patent" and "Invention and Industry" and blank form on which to disclose your idea. Highest references. Promptness assured. Clarence A. O'Brien, Registered Patent Lawyer, 2003 Security Bank Building. Directly across the street from Patent Office, Washington, D. C. Mi f= DURHAM! mm At dealers, or postpaid Durham <5l Co.. 1936 Market St.. Phila. Large Radio Wall Map E*D C ¥7 Tne very latest; up-to-date radio wall f IX r. F.nian 28 by 34 inches. Shows call letters, locations, wave lengths, and kilocycles of all radio broadcasting stations, U. S., Canada, and Mexico, relay divisions and radio districts. Also a scale for measuring distance. This wonderful map postage paid. ABSOLUTELY FREE. Merely send us a list of stores in your city which handle radio apparatus. Be sure and give the street address, and if you know the manager's name, give it also. DO IT TODAY before this offer is withdrawn. OZARKA INCORPORATED 808 Washington Blvd. Chicago ULTRADYNE TRANSFORMERS 1 Input Transformer and 3 Intermediate Transformers $20.00 4.00 Tuning, Oscillating Coils, per pair Full Instructions and Blue Prints furnished with each Kit. Absolutely guaranteed. These transformers are suitable for any Super-Heterodyne circuit. Put up In handsome Kit display box. Special discount to dealers. Prompt delivery. Write for special circular. SYPHER MANUFACTURING COMPANY 1524 Fernwood Ave., Toledo, Ohio S. HAMMER RADIO CO. 303 Atkins Ave., Brooklyn N. Y. STANDARD 4-TUBE SUPERDYNE Knockdown Kit — Complete Farts More powerful than a 6 tube naval receiver. Easy to build. I — Single Circuit Jack. I — Superdyne Coupler. 2 — 23-Plate Variable Condensers. I—Variable Grid-Leak. I— .00025 mfd. Fixed Condenser. 3 — Rheostats. 4 — V. T. Sockets. 2— Acme Audio Transformers. Wired Complete in <t/| C (\(\ Genuine Mahogany Cabinet «p"»«J.W I — Double Circuit Jack. 7x24 in. Panel, Drilled. 7x24 in. Baseboard. Bus Wires, Spaghetti and Diagram, etc. OUR PRICE $27.50 TUBE COCKADAY 4 CIRCUIT TUNER 1 Precision Coll. 2 Amsco 26 -PI. Cond. 2 Dubllier .00025 Fixed Condenser. 1 Amplex Grid Denser. 1 Bradleyleak. 3 Melco Sockets. 1 Pacent Double Jack. 1 Pacent Single Jack 2 Amertran Transformers. 1 Amsco Switch Lever. 20 1 Amsco Bheostat, 6 oliii.s. 2 Amsco Rheostats, ohms. 7 Switch Points. 2 Switch Stops. 1 Dubllier .0005. 1 Bradleyohm. 1 Panel. I Baseboard. Wire. Diagram, Etc. SPECIAL KITCOCnn Wired Complete inCCOnf) PRICE fr)J.U» Mahogany Cabinet..«PJJ-»u Orders over $5.00 will be shipped prepaid. Money orders or C. O. D. Not insured unless insurance charges included. Write for Price List. I operate a Marconi S-tube set and am bothered continually by a local amateur who persists in disturbing the hundreds of receivers in this city. A very heavy and cracking sound is heard when this amateur is transmitting code, which drowns everything else, as he is "all over the dials." If you think that one of these wave traps would eliminate this annoyance, please let me have early reply. A. — A wave trap will be efficacious in eliminating amateur transmission or spark if you are not too close to station. However, the disturbance to which you are subjected as described is quite unlike an amateur interference, which produces a high tone with a shrill note. We are very much inclined to the belief that your difficulties can be traced to inductance from an arc light or leaky power lines In your vicinity. If an amateur is violating the regulations governing operation the matter can be reported and his license revoked. Such would be the proceedings under our Federal rules. WHOLESALE FOR DEALERS AGENTS WANTED DEALERS — We make a specialty of stocking new dealers and radio departments. Our large price list will be mailed free to you on request. Good discounts and prompt deliveries. THE RADIO SHOP OF NEWARK, INC. 76 Springfield Ave., Dept. H. Newark, N. J. Panel Shielding After Your Set Is Finished A liquid metal: cuts out body capacity, brings in music clear and sweet. Done in 5 minutes. One can will shield 5 or more sets; 50c per can. Also a liquid spaghetti can be put on after set is finished, fine for insulating the base board, 50c per can. Post paid. WALKER MANUFACTURING CO. 247 Scott St. San Francisco, Cat. RADIO IheHrewPfanrtieM Ndn*©5cillatiitg Principle Com^eteOutJL^s^ S: Easy Mcnlhty Payments The season's biggest sensation. Carl Pfanstiehl's improvement over Neutrodyne, Super, Reflex, etc. Positively nonregenerative. Brings anew degree of musi Wrlte Today for FREE Trial Offer I Write quick and get our special price offer with 2 week's FREE Trial, and easy payments. 3, 4 or 6 tube seta. Write. MARSHALL RADIO PRODUCTS., Inc., Dept. C-584 Marshall Blvd. and 19th Street, Chicago, Ilk ARE YOU READY? Get your stock in shape for tmsl ness right now. Many new items have come out; yon need them. SEND FOR INFORMATION. r«ir TfK MuMM WE REPAIR THE FOLLOWING RADIO TUBES Dealers and Agents write for Special Discount Mail Orders Solicited and Promptly Attended to WD-11, WD-12, Our Specialties WD-11 82.50 WD-12 2.50 UV-200 2.50 UV-201 2.50 C-300 2.50 C-301 2.50 DV-6 2.50 DV-1 2.50 DV-2 2.50 DV-6A $2.50 UV-199 2.50 C-299 2.50 UV-201A 2.50 C-301A 2.50 Marconi 2.50 Moorhead 2.50 6 V. Plain Det 2.50 6 V. Plain Amp 2.50 H. & H. RADIO COMPANY P. 0. Box 22-A Clinton Hill Station NEWARK, N. J. ■