Radio Digest (Oct 1923-July 1924)

R A 1) 1 0 D 1 G E S T — illustrated February 2, 192 % ■ PER-HETRODYNE (.Continued froni page 26) clamping strip and terminal holder. The two holes marked OQ are for the oscillator grid coil *.4S turns). The two marked FOUR REQ.D-HARD RUBBER. Z HOLES DRILL * TAP 6-32' DRILL & TAP 3 -3Z" ■E (7) ONE REQ.D BRASS i c<f ^"h ^ — ~ — S -32 THREAD . L^O OP are for the oscillator plate coil (48 turns) and the two in the center marked DG are for the two rotor coils (28 turns each in series), which are connected to the first detector grid circuit. This variable coupling is not always YOU DON'T NEED TUBES to hear concerts from out of town. If you want to get new stations ON YOUR CRYSTAL SET write me today. I get new records every day from people using my plans who hear programs on Crystal from stations 400 TO 1000 MILES AWAY No tubes, batteries or amplifying apparatus necessary. I hear KDKA (Pittsburgh Pa.) on Galena. You may already have everything you need and just have it connected up wrong. Send selfaddressed envelope for picture of my set, and reasons why you need my plans. LEON LAMBERT 501 South Volutsia, Wichita, Kan. necessary, but as it is not very critical, it can well be added as it was found to have an advantage for clearing up any overloading of the first detector tube. The three strips number 2 are merely clamping and spacing strips for holding the fixed coils in proper position. Brass angles number 3 hold the fixed unit in proper relative position on the panel. The brass piece number 4 is the bearing for the rotor shaft and is mounted on the panel. The small stud is a stop pin which Kellogg Variocouplers SOI VARIOCOUPLER The Kellogg variocoupler furnishes coupling of the highest degree assuring maximum volume and clarity. The shells are of Bakelite treated to prevent distributed capacity. There are eleven stator and two rotor taps. Xo sliding contacts; rotors are made with special flexible wire through hollow shaft to binding posts on stator shell. Can be used as a splitvariometer. Large bearings warrant smooth operation and long life. Specify Kellogg and know you have the best If your dealer does not handle Kellogg communicate direct with us. KELLOGG SWITCHBOARD & SUPPLY COMPANY 1066 West Adams Street CHICAGO, ILL. A loud speaker on one tube TR1-C0IL for PEP! TKI-COIL Radio Frequency Transformers put "pep" intw a set"pep" of the kind that makes a Hie tube set operate a loud Speaker: And yet the list price is «2 only ™ CprC— "How To Build The TRIrfttL COIL Reflex" free at your dealer's or direct from us. BROOKLYN METAL STAMPING CO. 718 Atlantic Ave. Brooklyn NewYotV NAZELEY'S Folding Loop Patent Pending Folds up like an umbrellaWorks like a charm. Spread 28 inches Genuine Bakelite Facings; 85 ft. gTeen covered wire; rich mahogany finish. In an individual morocco covered tube. List $7 each One Dozen to a Case J. NAZELEY CO. S71 Hudson St. NEW YORK CITY limits the rotation of stop collar number 8. This stop collar slides over the shaft 7 and is locked into position with a setscrew. The four hard rubber collars number 5 are spacers which are slipped between the strips and prevent the coils from being crushed. The brass piece 6 holds the shaft at the proper angle when mounted on the inside clamping disc number 10. jL Burned Out or Broken A RADIO TUBES REPAIRED All Tubes Guaranteed to Work Like New Mall Orders Given Prompt Attention 24 HOUR SERVICE— All Tubes returned PJ>. CO J). RADIOTRONS WD-11 or 12 $3.50 UV-200 2.75 UV-201 3.00 UV-202 3.50 UV-201 A 3.50 UV-199 3.50 DV-1 or 2 3.M CUNNINGHAMS C-1I or 12 $3.50 C-300 2.75 C-301 3.00 C-302 3.58 C-301A 3.50 C-299 3.50 DV-« or (A 34» RADIO TUBE CORP. 70 Halsey St. Newark, N. J. SEND TO NEAREST REPAIR BRANCHES "RADIO TUBES" 39 West Adams St. Chicago, III. GLOBE ELECTRIC CO. 609 Cham, of Com. Bldg. Pittsburgh, Pa. RADIO TUBE SPECIALISTS 137 Market St. Phila.. Pa. WELLST0N RADIO CO. 1479 Hodiamont Ave. St. Louis, Mo. Crosley "Harko Sr." 1-Tube Receiving Sets Non-regenerative type. Brand new, in original boxes. WERE SOLD FOR $20 My Price $7.50 NO CIRCULARS— ORDER FROM THIS AD Prepaid While The Last TWITCHELLS RADIO HOME 1925 Western Ave. Minneapolis, Minn. The new TWITCHELL AUXILIARY TUNER connected to your present set will enable you to bring In the long and short ware stations which your : set cannot get. It also 4*uts out all local stations so you may bring in distance any time without local interference. Copyrighted diagram of this tuner 50c, or with all parts $9.00. Complete instrviment in walnut cabinet, ready to use, $15.00. Transportation prepaid. MY HIGHLY IMPROVED RE3NARTZ brings in all Important stations on this Continent loud, clear and without distortion. We dance to music from Atlanta and Los Angeles. Build one of these wonderful 3 tube sets from my blueprint and specifications, price 50c. or with a complete and perfect double-wound splderwcb coil $3.00 by mail. Picture of this set on a glass panel with every order. This copyrighted circuit is the most successful of any Reinartx modification yet produced, and is imitated the most. Thousands arc in use. My W. D. II Circuit is especially designed for use with the "Pickle" tube and brings out the full value of that little tube as no other circuit can. Stations 1000 miles away come in clearly on one tube. This set is small, complete, portable. For the man who wishes the highest efficiency, this 1« the set to build. Pries of blueprint and specifications. 50c. or with complete and perfect windings, $3.00. Photo of set with every order. Sets built from these copyrighted plan* will receive all broadcasting stations operating under the new laws. Their wave length range is from 170 to 800 meters. All goods prepaid. These instruments are easy to build, easy to operate. Everything clearly shown. S. A. TWITCHELL 1925 Western Avenue Minneapolis, Minn. The two small coils are clamped in position between the two discs 9 and 10. The outside wire of one coil (28 turns) and the inside wire of the other (28 turns) are connected together. The other end of (8) ONE REQ.D. BRASS TAP 6-32 FOR SET SCREW. each coil is connected to flexible leads which pass through' the hole provided in the inside clamping disc and are connected to the two center terminals on strip. These leads should be long and (Continued on page 28) fori ALL! tubes: T\ESIGNED to oermit infinite adjustment ■*-' of currents used in vacuum tube. G^ves absolute control ot electronic flow and finest tuning Possible. Fil-Ko-Stat will bring in DX you never .card before and shut out noise. 30 ohms full resistance. No adjustment to nuzzle. No discs to br-rk. No Carbon Powder. a AT AU . DEALERS] FILKOSTAT Mode and Guaranteed by DX Instrument Co. Hprrisburg, Pa. Radio Stores Com. . 2 1 8 W 34th St„ New York S"le IntematUmcl Distributers CLEAR RECEPTION ASSURED, A Crosley brings in distant Stations Easily. Listen to Crosley Broad cas ting Station WLW. "VTO MATTER which Crosley Receiver you choose, you can be assured of unexcelled performance at the lowest price. The Model X-J has proven especially popular. With it, Stations in all parts of the United States and Canada may be clearly heard. Even Honolulu has been frequently brought in from the eastern seaboard. Compare These Prices Crosley Model VI — a Two Tube Set 5 30 Crosley Model X-J — a Four Tube Set $65 Crosley Model X-L^^ Four Tube Consolette $140 Special Mahogany Stand for Model X-t. *t$ For Sale by Good Dealers Everywhere. Write for free Catalog. The Crosley Radio Corporation Powel Crosley, Jr., President Formerly The Precision Equipment Company and Crosley Manufacturing Company 2491 Alfred St.. CINCINNATI. OHIO The I,arffest Mannf:»ctnrers of Radio Receivers hi the World iininnniamamTO!::-!;:-!!-!;, ■ ■ ■■ msWkWkWmmmmkWkWkWm