Radio Digest (Oct 1923-July 1924)

February 2, 1924 RADIO DIGEST — Illustrated How to Make Inexpensive Neutrodyne Receiver Part II — Panel Layout and Assembly T By H. J. Marx HE selection of an 8 by 26-inch panel was decided on because of the better and more convenient arrangement of apparatus that was possible. The new fan usually finds considerable difficulty in the compact assembly and ACCESSORIES REQUIRED Four Amplifier Tubes. One Detector Tube. Six-Volt A Battery. Ninety-Volt B Battery. One Pair Receivers. Loud Speaker. Antenna Outfit. wiring of the set. Of course, with such a set the leads can be decidedly reduced in length, but with a little care and attention in wiring slightly longer ones need cause no concern. The three condenser dials with the variable grid leak and potentiometer are all in line across the potentiometer. Four bezels are used at the top of the panel so as to .permit observation of the lighting of the tubes. Three rheostats for controlling the tubes are arranged between the bezel holes. The rheostat on the right controls the two audio frequency amplifiers; the center one the detector tube, and the one on the left takes The baseboard is attached so a clearance of % inch is left underneath to permit fastening the panel to the cabinet. The arrangement of the apparatus on the baseboard in the rear can be seen in the photo reproduction. Wiring The leads should be kept as short as possible and covered with spaghetti wherever there is a possibility of contact with care of the two Radio frequency amplifier tubes. Three jacks in the lower right-hand side take care of plugging in on any stage of amplification desired. The two binding posts on the left are for antenna and ground connections, while the two on the right are for permanent loud speaker connections. With different makes of apparatus, the mounting holes may have to be altered to suit, but the relative location of the parts should be retained. another wire, the baseboard, panel or apparatus. Watch the grid and plate leads, keep them as short as possible and away, from other leads. Don't run leads through the air core transformers or you'll wonder why your signals won't clear up. One fan used a wooden panel and then wondered why he couldn't balance the set and keep it balanced. Don't connect the grid side of the secondary circuits to the rotary plates of the variable condensers and then complain PEERLESS RADIO, 349 Fulton St., Brooklyn, N. Y. Parcel Post prepaid on all orders above $5.00. Express Money Order, Certified Chock, Bank Draft accepted; also C. O. D. Guarantee with all merchandise. $65.00 GENUINE 5 TUBE NEUTRODYNE FADA PARTS. Ready to Assemble. $49.00. LOUD SPEAKERS Magnavox (new type) $27.25 Music Master 25.45 Pathe (new type) 16.50 Dictoorand 15.25 Strom berg Carlson 17.75 Mercury with Baldwin Unit... 9.95 Natl. Baldwin Type C Unit.. 4.85 Manhattan Electric 22.50 VARIABLE CONDENSERS II PI. Admiral or Signal $1.35 17 PI. Admiral or Signal 1.60 23 PI. Admiral or Signal 1.65 43 PI. Admiral or Signal 1.75 II PI. Montrose Vernier Good.. 2.55 17 PI. Montrose Vernier Cond.. 2.75 23 PI. Montrose Vernier Cond.. 2.85 43 PI. Montrose Vernier Cond.. 3.65 II PI. Ul S. Tool 3.35 23 PI. Ul S. Too4 3.65 43. PI. U. S. Tool 4.10 VARI0C0UPLERS Fisher, 180° Shamrock Sleeper, no taps Workrite Gillflllan, small Gillfillan. large Pathe Genuine All Wave Cockaday Coil Unxld. 180°, Bakelite VARIOMETERS Fisher, largo, 600 meter Shamrock , Sleeper Workrite Gillfillan. small Gillflllan, large Pathe .$2.35 . 2.65 . 3.75 . 2.95 . 5.95 . 7.45 . 3.25 . 5.35 . 1.85 . 1.95 .$2.55 . 2.65 . 5.65 . 2.95 . 4.95 . 7.45 . 2.85 PHONES Neroo $2.35 Pacent 3.45 Brandes Superior 4.85 Federal 4.95 National Baldwin Type C 7.95 Dr. Seibt, German Phone, 6000 ohms 5.85 Western Electric 8.85 Ambassador 3.50 Potter Precision 4.25 TRANSFORMERS Acme Audio and Radio $ 3.90 Ail-American (all ratios) 3.90 Federal No. 65 5.95 Modern 4.95 Thordarson 3.95 Erla Reflex and Audio 4.45 Akracy 3.35 Modern Push-Pull 10.75 Como Push-Pull 10.75 CYCLONE BATTERIES Small 22'/2 Volt. $ .75 Large 22'/2 Volt 1-75 Medium 45 Volt 2.30 Large 45 Volt 3.45 Urge 22'/2 Volt Eveready Battery 2.35 Large 45 Volt Eveready Battery 3.65 Small 22'/2 Volt Eveready Battery 1.15 Eveready "C" Battery. 4'/2 Volt 55 HARD RUBBER PANELS 10 $ 12 14 18 21 24 S .70 .90 1.00 1.40 1.65 1.85 MAHOGANY CABINETS 10. 12. 14. 18. 21. 24. .$2.45 . 2.65 . 2.80 . 3.05 . 3.35 . 3.65 Bell Socket, Bakelite Panel Mounting $.69 Amsco 6 ohm Rheostat 95 Amsco 20 ohm Rheostat 1.15 Amsco 30 ohm Rheostat...... 1.25 Amsco 400 ohm Potentiometer. 1.40 CutlerHammer 6 ohm Rheostat. Plain 95 Cutler-Hammer 6 ohm Rheostat. Vernier 1.20 MISCELLANEOUS CutlerHammer 30 ohm Rheostat, Plain $1.20 Cutler-Hammer 400 ohm Potentiometer 1.20 Filkostat 1.85 Bradleystat or Bradleyleak 1.70 Bruno 14 Tap Inductance Sw.. .70 Sta-put Phone Plug 35 Phone Plug tor 6 pr. Phones.. 1.25 Phone Plug for 2 pr. Phones.. .60 Single Circuit Jacks Double Circuit Jacks 4" Dials, Fada Type 3" Dials, Fada Type Triple Sockets, Fada Style... Marked Ebony Binding Posts, Each Ambassador Coil Shelton Midget Vernier Freshman Grid Leak & Cond, $0.35 .45 .45 .30 2.65 .17 5.95 1.40 .75 that the set has too much body capacity. Shield your panel if you want to, but watch out for short circuits. Check your hook-up carefully and be sure you have it right. Don't use so much solder that it requires a cold chisel to remove the surplus. That's no joke, the writer had to do that with one set he tested. The set worked fine after a little checking over. Theory of Neutralization In order to present the theory of neutralization, a long introduction dealing with equations, formulas, tube characteristics, transformers, capacity reactions, and what not, would be required; so, possibly, analogy will do more toward explaining the situation than a theoretical discussion that will leave the fan bewil(Continued on page 24) Standard Merchandise Only S. HAMMER 303 ATKINS AVE. All Sales on a MONEY RADIO CO. BROOKLYN, N. Y. BACK GUARANTEE Anything and Everything in Radio $65.00 GENUINE FADA PARTS FOR *CA flO 5 TUBE NEUTRODYNE SET ^Dt.W List Our Price $ 2.25 Filkostat $ 1-90 2.00 Bradleystat 1.75 2.00 Bradleyleak 1-75 PHONES $ 5.00 Nereo 3000 Ohms $ 2.40 12.00 Western Klectric 8.95 6.00 Brandes • 4.75 12.00 Baldwin 7.95 7.00 Federal ... 4.95 6.00 Potter Precision 4. 15 TRANSFORMERS $ 7.00 Federal No. 65 $ 5.45 5.00 Acme 3.85 5.00 All-American 3.85 7.00 Amertran 5.75 5.50 Thordarson 4.50. 12.50 Como Duplex Pushpull, pair 10.50 5.00 Akracy 3.95 5.00 Modern 3.95 5.00 Erla 4.25 BATTERIES $ 5.50 45 Large Eveready or Cyclone $ 4.00 2.75 45 Small Eveready or Cyclone 2,25 2.75 22% Large Eveready or Cyclone 2.25 1.50 22% Small Eveready or Cyclone 1.35 CONDENSERS $ 2.00 Signal 11 plat© $ 1 .40 2.50 Signal 23 plate 1.60 2.75 Signal 43 plate 1.65 2.50 Admiral 11 plate 1.45 2.75 Admiral 23 plate I 65 3.25 Admiral 43 plate 1.80 6.00 Hammarlund Vernier 11 plate 4.95 6.50 Hammarlund Vernier 23 plate 5.65 7.00 Hammarlund Vernier 43 plate 6.25 4.50 U. S. Tool Vernier 11 plate 3.50 5.00 U. S. Tool Vernier 23 plate 3.75 5.50 U. S. Tool Vernier 43 plate 4.25 A 5 TUBE NEUTRODYNE set with Genuine Fada parts, wired complete in Mahogany foe on Cabinet without tubes or batteries "POJ,uu List AMSCO PRODUCTS Our Price $71.00 AMPLEX KIT $56.50 1.80 11 Plate Variable Condenser 1.65 2.30 17 Plate Variable Condenser 2.05 2.50 23 Plate Variable Condenser 2.25 3.50 43 Plate Variable Condenser 3.00 4.00 11 Plate Vernier with Bakelite Dial 3.50 4.50 23 Plate Vernier with Bakelite Dial 3.95 5.00 4,3 Plato Vernier with Bakelite Dial 4.45 1.00 6 Ohm Kheoetat with knob 85 1.25 30 Ohm Rheostat with knob 1. 10 1.25 6 Ohm Rheostat with dial 1. 10 1.50 30 Ohm Rheostat with dial 1.35 1.50 400 Ohm Potentiometer with dial 1.30 1.75 400 Ohm Potentiometer with dial 1.55 2 inch Bakelite Dials 40 3 inch Bakelite Dials 60 4 inch Bakelite Dials 1.00 Lavite Resistances, 48,000 ohms 1.25 Amplex Grid-densers 1.25 5.50 Cockaday Coils. Genuine Precision 4.50 Tube Socket, table mount 1.00 Tube Socket, panel mount 1.25 LOUD SPEAKERS $30.00 Music Master $24.00 35.00 Magnavox 29.00 25.00 Dlctogrand 18.00 55.00 Western Electric D-10 45.00 30.00 Stromberg Carlson 24.00 VARICOUPLERS $ 3.50 Fisher 180 deg. or straight $ 2.50 3.50 Workrite 180 deg 2.95 8.00 Gilfillan 6.00 4.00 Simplex 180 deg. silk wound 2.80 3.25 Shamrock 2.60 4.00 Sleeper Fixed 3.25 7.00 All Wave 5.50 ALL MAIL ORDERS SHIPPED PROMPTLY. Orders C.O.D. IF IT IS NOT LISTED HERE ASK over $5.00 will be shipped prepaid. Money orders or U S— W E HAVE IT AT REDUCED PRICES 2-LO, LONDON, ENGLAND ON ONE TUBE Another Record for the ELGIN SUPER-REINARTZ Tuesday, November 27, during the test period between 9 and 9:30 P. M., Rev. E. A. Cole in the residence of J. A. Mclver, of Roodhouse, 111., while operating a set made of materials and in accordance with the hookup furnished by the ELGIN RADIO SUPPLY CO., tuned in 2-LO, London, England, using receivers and but one tube. Later another tube was lighted and the loud speaker used, so that four people could hear the program and concluding announcement. The numbers, time, and the order in which they were played were Officially Confirmed by the St. Louis Post Dispatch in conjunction with the National Association of Broadcasters, who had charge of the tests. (See page 34, St. Louis Post Dispatch, Dec. 2, 1923.) This same hookup has been advertised extensively as the one which brings in stations 2000 miles overland on a loud speaker and one tube; and this has been demonstrated so often as to need no repetition. Send a two-cent stamp for circular giving one, two, and three tube hookup, and price list of parts for this remarkable circuit. Address the ELGIN RADIO SUPPLY CO. 207 Chicago St. ELGIN, ILL.