Radio Digest (Apr 1925-Jan 1926)

22 RADIO DIGES T— Illustrated April 18, 1925 Questions and Answers Pive Tube Neutrodyne (13219) EFC, Queensland, Australia. Having received good results from the making of your five tube neutrodyne, unfortunately the wave length is low compared with the wave length of the stations here, which range from 200 to 1,800 meters. I am very anxious to construct one that will include the above wave length and would be thankful if you would supply a layout with instructions. A. — It would be quite difficult to get a neutrodyne that would cover the range you mention. We would suggest that you experiment with different ways of accomplishing this range. Try using condensers having a very high capacity, to be connected in parallel to the tuning condenser. This method may cover the range as desired. It would be a good plan to use variable neutrodons so that their settings may be marked. By using these variable neutrodons you can experiment with different neutroformers and mark the settings of the neutrodons. If you use coils of the honeycomb type you will need about three sets of coils to cover the range. Adding' Stage of Amplification (13150) JEG, New Orleans, La. I have at present a three tube set using a detector and two stages of audio frequency amplification, but I would like to add another stage. Can this be done with a low ratio transformer, say 3 to 1? "Would there be any distortion of the signals? A. — With the new type of transformers you may add another stage to your present set. These new transformers are shielded and have features that will prevent distortion, one of which is a large core which tends in high ratio to eliminate distortion. Three Circuit Receiver (13112) DM, Vancouver, B. C, Canada. In looking over my back number of Radio Digest for a three circuit hook-up I found one in the September 27 issue and made it as described therein. With this hook-up I can get only up to 475 meters. "Why is it that I cannot get a greater wave length? Is there anything I can add to increase the wave length? A — If you cannot get the upper waves we would advise you to add about twenty turns to the 40-turn coil, and if you should find that this goes too high so that you cannot get the lower wave lengths reduce the turns about two at a time until the correct number is reached. ZELLEBS RADIO LOG BOOK, 25 Cents. ,Zellers Company, Hooper, Nebraska. OCTAGON RADIO LOG lists EVERY 500watt station in United States and Canada alphabetically by cities on ONE card. Spaces for 24 extra. Handier than log book. 15 Cents. F. Kern, Oswego, N. Y. Log for Your Radio NEW 64 page tog. Holds 400 stations. Shows calls, cities, wave lengths. 4 dial settings, remarks, etc. TUNING SUGGESTIONS. Station list by wave lengths— by states, etc. Owners. Map. TROUBLE AIDS. Other valuable information. So convenient. Worth many times email cost. A joy to nse. GENUINE De Lose leather cover. Or) lv$ 1 . ; j S„_j xj_ Ayf^wATT Pav postman after log arrives. Postend INO Money oaid if pay with order. MONEY REFUNDED if not DELIGHTED. Order today— NOW. Postal will do RADIO PRINTERS, Dept. 9914 Mendota, Illinois $10.00 IS ENOUGH You can hear programs from cities 400 to 1,000 miles away on Lambert Crystal Sets and you won't need tubes or batteries. Picture of set and particulars free. LEON LAMBERT 501 Kaufman Bldg. Wichita, Kansas Dealers write for discounts. Radio Tubes Exchanged Bend US yam n]t] tube — any make — any condition— and we will >end you a Brand New ) Guaranteed Tube, of whatever type you [require, for SI. 73. All shin *» — __ menti by insured Parrel {p T /5 Post C. O. f). Send no money —order today D-R-C RADIO CO. C.O.D. 327 S. LaSalle St. Chicago, III. TUBE SET$ 45 Assembled Complete WHY BUILD WHEN YOU CAN BUY the D-R-C Ci iletely A emblcd Wonder Set— the 5-Tube Tuned Radio Frequency Receiver that out' four times as cosily -Direct from the the amazingly low price of S45. Users ure coast to coast loudspeaker reception. Beautiful Cabinet— Bakelite Dials and Panels — fuir I materials throuphout — easily operated. Send money order today for the factory-built, factory-tested and FULLY GUARANTEED D-H-C WONDER 8ET at the rock bottom price of $1", f. o. b. Factory. Write for complete list of Accessories. D-R-C 329 S. La Salle St! CHICAGO J_ 6 06 6 6 1Q.&A.-12863 M«W + A-+c b+ e> + Circuit Wanted (12863) RCH, Rowan, Iowa. Will you please send me a diagram (plain) by which I may construct a 2 or 3-tube Radio set from the parts as listed below? I want one that a novice may easily follow and that which leaves nothing to the imagination for I know little about making one, but have the following parts and would like to make use of them. 1 .0005 variable condenser. 1 .00025 variable condenser. 1 three circuit tuner, low loss 1 .00025 fixed condenser. 1 .001 fixed condenser. 2 3 to 1 Radio transformers. 1 10 to 1 audio transformer. 3 standard sockets. 3 6-ohm rheostats. 1 30-ohm rheostat. Hook-up wire, also panel 7 by 12 ins., baseboard and cabinet. I have not found any hook-up presented in Radio Digest that I can follow with the materials I have on hand. A. — The accompanying hook-up can be used to take up most of the parts you mention in the list. Men to build radio sets In spare time. Leon Lambert, 501-H Kaufman Bldg., Wichita, Kansas. PATENTS Time counts in applying for patents. Don't risk delay in protecting your ideas. Send sketch or model for instructions or write for FREE book, "How to Obtain a Patent" and "Record of Invention" form. No charge for information on how to proceed. Communications strictly confidential. Prompt, careful, efficient service. Clarence A. O'Brien, Registered Patent Attorney, 2009 Security Bank Bldg. (directly across street from Patent office), Washington, D. C. PATENTS SECURED Radio Inventions a Specialty Trade Marks Registered WRITE US Mason, Fenwick & Lawrence Patent and Trade Mark Lawyers Washington, D. C. Now York Chicago ESTABLISHED OVER 60 YEARS — *• PROTECT AGAINST ~ m. LIGHTNING Install Now a Lew Lots KEYSTONE Approred ARRESTER «lf£ Reactivating Tubes (13109) RLS, Snyder, Okla. Is there any way to reactivate the TJV201A tube which burns good? We have about twenty which came in a shipment of about 125 tubes. We did not test them at the time and six weeks later we found this number to be inactive. They are new tubes and there should be some way to have them reactivated. Can you tell us a way to give them life? A. — If the filament still lights the tube may be improved by burning it at the stated voltage, 5 volts with the UV-201A, for a period of about ten hours. The plate Thank Your Favorites. Individual applause cards, 100 for ?1, with your name and address. Press, Jamestown, Indiana. Buy rigrht and make money. ^MB Standard lines, parts, sets, ^3 • shipped now. Fast service^ — hard-to-get items — extra good discounts. Get our catalogue No. 8. It shows you! W. E. PUETTEREB RADIO SUPPLY CO, 2121 Locust St. St. Louis, Mo. A REAL FIXED DETECTOR TAKES PLACE OF TUBE .For REFLEX ^and CRYSTAL SETS or Operates as a crystal set in itself. Stands Keflex Toltage. lasts indefinitely, because of readjustment feature and does away with bothersome catwhisker and hunting for Hot Spot. Tou can depend on it being always "Hot." Get greater distance reception on CRYSTAL SET. Save A and B battery and Tube life, get better detection than Vacuum Tubes. Get a BADETEC and know the joy of real reception. Packed in box with Brackets and Instructions prepaid for $1.00. Every one guaranteed. Dealers Write for Discounts TOWNER RADIO UFO. CO. 2620-A Victor St. Kansas City, Mo. Premier CROFOOT" Vario Condenser "Look for the Red Stripe" ^,rAtetfOr1wfreL0opy of Vernier Bulletin No. 94 giving full description of the many new features of this remarkable low loss condenser, as well as particulars of all Premier Quality Radio Parts. "CROFOOT" has lowest minimum capacity; only five minute phase angle loss; tuning ratio of 1 to 74. Made of brass ^^and hard rubber throughout, for ^■low resistance. $2.75 to $3.75. Vernier complete with dial, 75 cents extra. Write for bulletin and FREE HOOK UPS. Premier Electric Co., 3810 Ravenswood Ave., Chicago FREE * 616 beautiful genuine copper etched American and Canadian stamps FREE, yes, absolutely FREE, with order for a genuine Bryant 48 page stamp album (8 in x 11 in.). Also contains log showing stations, locations, ware lengths, dial settings and date. At you hear new stations just stick th< proper stamps in your album. Colored individual stamp for each station. So convenient. So enjoyable. Tou will be proud to show this album to your friends. You and vour children wfll enjoy it. Com plete album $3.98 plus postage. SendNoMoney Just pa; postman after album and stamps arrive. I prepay postage if you prefer to pay with order. MONEY REFUNDED if not DE LIGHTED. Send order today— NOW. Postal wfTt BS P. M. BRYANT, Dept 9414. 366 Wrigley Bldg, Chicago For a Limited Time Only Too emu purchase lor S3.SO a it cell 14 volt RABAT SENIOR battery. Saving S6.I0 thro direct baying. 14 cell 48 volt size $7.00 Rabat Senior batteries arc neat, powerful, noiseless. Separate etear glass cells and patented rubber cork with heavy duty plates 3/16' x V x Z I'Z with slaggcrd ribbed grid form the backbone of (his sturdy battery Shipped completely charged ready to use. Order now, save Jo.10 Rabat Super Charger $3.00 e. o. d. Specially designed to ulisfactorily recborge any storage "B" heltery. Shipped complete ready to use, including lamp socket. Btuchmeat plug Hid cord. You myc $1.80 by ordering direct. THE RADIO RABAT COMPANY 1 767 n. cum avinus cuuumx voltage should be turned off. There should be no other connections. Tou may have other troubles with these tubes which cannot be fixed by these simple methods. Improving Two Tube Reflex (13232) EGM, Georgetown, Conn. I have a Harkness two tube reflex in which I use WD-12 tubes with 45-volt B battery. With this set I get good results as far as distance is concerned, but the advertised loud speaker volume is conspicuous by its absence. I wish to know if 6-volt tubes will increase the volume? What is the proper B battery voltage? I have tried 90 volts and this cuts down the volume. Can a resistance-coupled amplifier be hooked up to this set, and, if so, will you please send me a hook-up for it? A. — Tou should not expect to get much volume from this set with WD-12 tubes and 45 volts on the plate. If you use UV-201A tubes you will have no trouble with the lack of volume. It is advisable to use resistance-coupled amplifiers with the WD-12 tubes. Salesmen calling" on radio dealers wanted to handle Radio Tubes as a side line. The Thoria Tube Company, Dept. "D," Middletown, Ohio. GO into the RADIO BUSINESS We specialize in Equipping New Dealers with entire stock — ADVICE P&EE. Send for Our Radio CATALOG & BARGAIN LISTS Wholesale Only MANHATTAN RADIO CO. 112 Trinity Place New York City Throw Away your Iiog Books and nse THE ACCURATE DIALING CHART It gets your Stations regardless of the Wave Lengths changing'. Price £0s> Postpaid ACCURATE DIALING CHART CO. Kingsburg, So. Dak. ONE DOLLAR brines you this Radio Cabinet with Solid Walnut ktop, in Walnut or Mah. finish. Look it over and if It meets your ap18" $6.50 proval pay expressman balance. It''::::."::: I'M harper mfg. co. 26":::::::: 9:00 cassopoiis, Mich. DUNLAP'S RADIO CALL BOOK Listing all Broadcasting Stations Always Up-to-Date Changes Mailed to you Each Month for a Year Up-to-date international call book compiled by Orrin E. Dunlap, Jr., Radio Editor, The New Tork Times, includes 4 columns for dial readings, owners, wave lengths, power and slogans. Immediate delivery Send $1 for book including monthly service for a year that keeps your A station list always accurate. Cor $ rection pages have gummed edges easily attached in back of the book. Send cash, check, stamps or money order. DUNLAP'S RADIO CALL BOOK SERVICE Box 88, Flushing, N. V. 1 Profit by Your Meteorological Observations The editor of TYCOSRochester, a meteorological journal published by Taylor Instrument Company, Rochester, N. Y., seeks to review manuscripts based on observations of atmospheric phenomena, its effect on radio reception, with a view to publication in above magazine. Prevailing space rates paid promptly on acceptance. All material reviewed promptly. Addressed to the personal attention of F. M. Herrick, Editor Tycos-Rochester, Taylor Instrument Companies, Rochester.. N. Y.