Radio mirror (Jan-Oct 1923)

RADIO DIGEST May 12, 1923 THREE TUBE REFLEX (Continued from page 17) to the fixed plates of the variable condensers. For this reason care should be taken that neither the angles or the brass screws for mounting come in contact with any of the apparatus or wiring, this creating a short circuit. If the holes for the mounting screws are sufficiently countersunk in the sub-panel they will not come in contact with any of the apparatus mounted on the top of the panel. Sub-Panel Layout The layout of the sub-panel is shown in Figure 2. It will be noted that the two Radio frequency or reflex transformers are mounted on top with the three tube sockets and the binding posts. The three audio frequency transformers were suspended from the underside of the panel. The center transformer was found long enough to rest on the base of the cabinet when the panel was in place and thus acts as an additional support for the sub-panel. All holes for mounting suspended apparatus were countersunk sufficiently so that the heads of the screws for mounting were at least aSi-inch below the surface of the panel. It might be well to suggest that a number of holes about -ft-inch in diameter should be drilled in this sub-panel before any mounting is done. These are for passing through the leads for connections between the upper and lower instruments. It will probably be necessary to drill some after the apparatus is in place but some trouble will be saved. In the next part of this series the details of wiring will be taken up. (TO BE CONTINUED) such relation to the taps on the tube that when it is mounted on the panel the taps will be on the side of the tube and not on the back or front in relation to the panel. This point is shown in Figure 2. This results in increased efficiency of the set because of the short taps that it allows us to make. Connections Should be Short This point brings us to a very important thing to be considered when any kind of a Radio receiver is being built or designed. That is the very great importance of making all of the connections in the set as short as we possibly can. If we remember this point and do our best to carry it out in our set it will result in our having a receiver that not only looks good and works good, but one in which it is very easy to follow connections, and it will often be found that this last is no small consideration being of especial value in amplifier circuits. In order that we may start to assemble this set we will take up in our next article the layout of the panel, and why, and I believe that the why of panel layouts will show several things of interest to some of us. (TO BE CONTINUED) FLIVVER SUPER SET (Continued from page 15) found suitable and no absolute number is given because it is not critical and will vary with the ball used and the size of wire, and No. 28 or 30 wire will be found very good. Do not attempt to put as many turns of wire on the ball as you can because you will only defeat your purpose. We have simply described the ordinary variocoupler with more than the usual number of turns on the rotor and so one can, if they desire, use a standard variocoupler and rewind the rotor ball to meet the requirements of this receiver, that is to the 100 to 125 turns. If more than this number of turns are used, one will encounter trouble when using the set as a straight regenerative set. The shaft for the rotor should be in Stops Singing Noise If there is a continual singing noise when the amplifiers are used it is caused by the tubes or amplifing transformers being too close together. If available space is limited place the transformers at right angles. It is not advisable to use more than two stages of audio frequency amplification. ^___^___^_____ At least 50 per cent of the efficiency of a receiving set depends on the skill of the operator who is tuning it. The Reader's View FleweUinff Set Just finished a Flewelling set with no other information or directions than that published by your valuable paper and say boy! she sure puts the old crystal set in the shade on the north hill side. Everything but the "WD 11 tube is homemade, including variable "Vernier condenser, honeycomb coils and B battery. Hale Brothers, KPO, of San Francisco are now broadcasting and it sounds just like it was in the same room. Calgary, Alberta and Kansas City (Sweeney Auto School) and Ft. "Worth come in like a house-afire and the Portland Oregonian Hoot Owls need a muffler to hold the volume down so that they can be heard. The Los Angeles Examiner comes la splendid and occasionally Denver. Am going to assemble the set on a panel and expect to get some real good results then. There has been a good deal of criticism of the Flewelling in Spokane but that's the builders' fault, not Fiewelling's. Well, I must sign off but want to tell you w,ant the Radio Digest is the best and most up-to-date literature on the art of Radio communication seen in these parts. Good luck to you. I'd sooner miss my meals than the Radio Digest. — Carl Raney, Spokane, Wash. Advance Programs Permit me to congratulate you on the innovation in this week's issue — "Advance Broadcast Programs" — that alone is worth more than your subscription price warrants and will be of inestimable benefit to all "phones." — F. W. Sykes, Chicago, Illinois. 1000 Miles Guaranteed on One Tube A real radio set at a low price Consisting of the following parts: 180° Variocoupler, Variable Condenser, 7xlS Panel already drilled, 2 Dials, Switch Lever Points Stops, Rheostat Socket, Binding Posts, Bus Bar» Sphagetti, Lugs and complete blue print to assemble in one-half hour. At the special low price $15.00 Two Stage Amplifier for above $15.00 $5.00 Audio Transformer $2.95 $5.00 Variocoupler, 180° 2.25 $1.25 7x10 Panels 8) $1.00 PhonogTaph attach single 50 $6.50 1*4 Volt Tubes Guar 3.95 .50 W.D.ll Bakelite Socket 35 $8.00 Long range receivers $4.50 $1.00 Freshman Var. Leak & Cond 75 .75 Freshman Var. Leak only 60 $5.00 Elect, soldering Iron 3.75 $5.00 Detector Tube Guaran 3.50 $6.50 Amplifier tube, Guaran 3.95 Write for complete list of other bargains 132 Nassau Street, Dept. R. D. NEW YORK CITY, NEW YORK ECONOMY RADIO CO., Type C for Reflex Sets, $2.50 Type B for Crystal Sets. SI. 50 LISTEN— REFLEX FANS To this good news. Here is THE ONE THING NEEDED to make the REFLEX SINGLE TUBE set a GREAT instrument— A REAL LIVE PERMANENT DETECTOR to take the place of a crystal detector. No special wiring, connect the same as crystal detector. We have set aside 100 B-METAL REFLEX SPECIALS TUBE Type Non-Battery PERMANENT DETECTORS and having given them most exhaustive tests, are ready for your verdict, so fill out the attached coupon and mail at once as this offer is limited to the first 100 applicants, one detector to each. B-METAL REFINING CO. 3134 Trumbull Ave., Detroit, Mich. B-METAL REFINING CO. 3134 Trumbull Ave., Detroit, Mich. ■ Send post paid ODe B-METAL 'REFLEX DETECTOR. I I will test same and return detector or price within [ five days. I if ail I to Address. "MAKE PERFECTION YOUR SELECTION" We Carry Only STANDARD Advertised Radio Equipment. Every Product Sold on a MONEY BACK GUARANTEE. Add 5"/o on purchases above $10. Add I0°/o on purchases below $10 — for Parcel Post FREE * « V°L™pE,TfcRHAlEA0MFMSES?"IS 0-lVEERN *"" *"" F^E MAGNAVOX LOUD SPEAKER. Type R. 3. $27.45 FLEWELLING CIRCUIT. Complete parts, including DRILLED panel. double coil Mounting and Honeycomb coils: only standard equip ment used. FREE DIAGRA H $17.75 PERFECTION VARIOCOUPLERArt 0£ SILK WOUND. Fibre Base. J%A.AQ List $5.00. Our Price »r — • DICTAGRAPH PHONES. 3000 <CK 7^ Ohms. $8.00 List «P*J. # *J N. & K. PHONES. 6000 Ohms. <CC Kf\ None Better Made «p\J.*#V PERFECTION VARIOMETER. *, r» ng Guaranteed Quality. List $5.00. JS^.yO Our Price s. ~ ACME TRANSFORMERS. Type A2S. $5.00 List... $4.25 KL0SNER VERNIER RHEOSTATS. List $1.50 59c REINARTZ CIRCUIT. Com a ■* ■% r\C plete parts including Drilled Jk I .HJ> Panel. FREE DIAGRAM ... «P * * ••'*' REINARTZ COILS. Very Best Quality. . $1.75 MICA DIAPHRAGMS Improve your phone. Our Price. List $2.00. $1.25 THORDARSON TRANSFORM CO OC ERS. $4.50 List ip%J,£*%J BALDWIN PHONE. Original <JM 7^ Nathaniel. List $6.00. Special. .«J^*« * *J 180s BAKELITE COUPLER. Silk Wound. List $5.00. Our Price $2.95 VARIABLE CONDENSERS List Our Price Price 3 Plate Vernier Condenser, moulded ends $ 1-50 $ ll0 11 Plate Condenser, moulded ends, .00025 2-o0 I-35 43 Plate Condenser, moulded ends, .001 4.00 2.00 Franco 23 Plate Variable Condenser with Vernier 6.60 4.00 Franco 43 Plate Variable Condenser with Vernier 7-70 4.50 HONEYCOMB COIL MOUNTINGS Triple Mountings with leads — screw adjustment 5.00 Double Mountings witk leads — screw adjustment 3.50 Single Mountings 55 BAKELITE PANELS 2.75 2.45 .40 7x10 7x18 Alf Panels 3/16 inch 'thick! ' 1.25 2.25 3.25 CROWN TRIPLE COIL MOUNTINGS. $5.00 list. Special IpOii/O PHONE CONDENSERS All Capacities Fixed Condensers. Grid Leaks, etc $0.30 Freshman Variable Grid Leak 75 Freshman Variable Grid Leak and Condenser combined 1 .00 All capacities of Dubilier Micadons and Freshman Micons in stock. HARD RUBBER PANELS 7x10 Unbreakable 7x18 L'nbreakable 7x24 Unbreakable BATTERIES EX3DE "A" Storage Battery. 6 V. 40 Amperes Hours. Type 3 LS.L5 17.85 EXIDE "A" Storage Battery. 6 V. SO Amperes Hours. Type 3 LXL9 23.10 EXIDE "A" Storage Battery. 6 V. 120 Amperes Hours, Type 3 LXL-13 31.50 Everready "A" Variable Storage Battery— 6 V., 90 Amperes Hours 18.00 Everyready "A" Storage Battery — 6 V.. 98 Amperes Hours 18.00 Everyready "A" Storage Battery — 6 V.. 110 Amperes Hours 20.00 Everready "B" Battery — 15 V 5.50 Everreadv "B" Battery — 22«. V 3.00 Volton "B" Battery— 22U V ! .75 Bright Star "B" Battery, 22% Volts 1.75 Bright Star "B" Batten 3.00 Bright Star "B" Battery 5.00 22V> V. Variable. 5 Positive terminals 1.75 Bus Bar Wire (2 ft. lengths) $0.09 .60 .85 1.50 1.95 16.00 18.00 3.95 2.20 .95 1. 10 2.00 3.50 1. 10 .03 PERFECTION RADIO CORPORATION, 121 West 23rd St., NEW YORK CITY STORES ALSO AT 59 AND 78 CORTLAND ST. AND 128 CHAMBERS ST. WHOLESALE AND RETAIL warn m f&&%f$ Bound Volumes Numbers Two, Three, or Four Postpaid by Parcel Post with One Year's Subscription to Radio Digest %$s «v # r/. -NT v iNumbei VOLS. TWO, THREE & FOUR Now Ready for Delivery. Par tfo (\T\ eel Post Prepaid, Each, Only «P*. W On account of the limited supply, the sale of these bound volumes is limited strictly to those readers of the Radio Digest who have subscribed for a year. One year subscription to Radio Digest and both bound volumes <f7 f\f\ 2 and 3 or 3 and 4 V'-U" By subscribing now for one vear to th? Radio Digest you get both BOUND VOLUMES 2 and 3. 26 numbers, with one year's subscription, for S7.00. One year subscription to Radio Digest and bound volumes, 2, 3 CJQ nr\ ALL ORDERS MUST BE SENT DIRECT— No orders on this offer will be accepted through subscription agencies news dealers or other sources. Check money or express orders (no stampsi must accompany all orders. Greatest Collection of Radio Information Ever Published Reinartz Long Distance Circuit UltraReinartz Circuit Flewelling "Flivver" Circuit Grimes "Inverse Duplex" Circuit Single Tube Reflex Circuit Armstrong "SuperHeterodyne" Circuit Two, Three and Four Tube Reflex Circuits A. B. C. Lessons for Radio Beginners In addition to these features these rolumes contain many instructive articles, receiving set diagrams, how to make articles, new apparatus, pictures and illustrations, hook-up diagrams, broadcasting stations, technical articles and hook reviews. 13 Numbers in the Bound Volume 52 Numbers in Year's Subscription COUPON PUBLISHER. RADIO DIGEST. 123 West Madison St, Chicago, Illinois. Please reserve me Bound Volume Number Two and also Number Three and one year's subscription to the Radio Digest, for which I am inclosing check— M_ O. for Seven Dollars. 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