Radio Digest (Oct 1923-July 1924)

RADIO DIGEST — Illustrated March >'.), 192Jt FIXING WHATS WRONG tickv. is the stroi high-frequency oscJlla l receiver, with tuned ■t of the secondary in ond. Even the three-circuit ent energy to when the vacuum tube primary circuit are in der to cut •ion from a single-cir3i niause a variometer the plate circuit instead of the I. While it is true that h of the re-radiation Interference at -ent. in the form of whistles and can he traced to single-circuit vers, this is generally due k of tuning experience on the .tor. A two-circuit reer manipulated by the same operator Id undoubtedly give out as much ine. In fact, any regenerative reer will re-radiate interference if it properly handled. To master the coredure in tuning: requires no more t than the highly i d lesfrable one reve, and more satisfactory re will be obtained. Atmospheric Disturbances Every Badiophan is familiar with the latching and sometimes noises due to atmospheric dis5, which cause such distracting interference to reception. The elimination of the noises, variously called '"strays." ■•atmospherics," or "static," is one of the baffling problems of Radio yet e solved. Many intricate circuits and arrangements have been devised to offset the effect of static disturbances in commercial Radio communication, but although interference from this source is thereby greatly reduced, it cannot be entirely eliminated by present means. Atmospheric disturbances are more severe during warm weather, but even during the winter months when a change of weather is imminent, or during mild periods, static discharges will take place. At times, it is possible to hear such disturbances even when occurring at considerable distances, although they are most bothersome when propagated in the immediate vicinity. The intensity of this sort of interference varies in different parts of the globe, being at its maximum in the tropics and falling off considerably in the temperate zones. Electric Waves The most troublesome sort of static is that duo to electric waxes in the ether, similar in nature to Radio waves, and ,d by atmospheric disturbances in .>. Lightning Hashes caused by the sudden discharge of heavy accumulation Of small static charges set up powerful disturbances in the ether. Obviously, not all lightning discharges flash to earth, many of them occurring inside of or between clouds. The resulting effect is the emission of electric waves, which are reproduced by induction in the receivers, causing Interference to good reception. Since the waves thus propagated are so similar to Radio waves in nature, the problem of the complete elimination of static presents very great difficulties. Electrical disturbances, originating at sources which have no connection with Radio communication, are often times the cause of reception interference unknowingly attributed to static. Inductance interference of this sort may be due to sparking of electric motors or generators, caused by improper brush contact, poor commutation, burnt-out coils or heavy overloads. The high-potential discharges from x-ray machines produces intermittent interference which is exceedingly difficult to eliminate, although it may be considerably reduced by shielding themachine and grounding the shield. Electric arc welding outfits and arc lamps also create similar disturbances. Interference from Power Lines Indu'ction from power or lighting lines carrying alternating current produces a humming noise in the receiver, distorting the reception. The receiver installation should be made as far removed as possible, from any lighting circuit in the room, and the antenna should be installed as nearly as possible at right angles to any nearby power lines. All these sources of interference, although producing electrical disturbances with only small amounts of energy, are very bothersome in their effect upon sensitive Radio receivers. (TO BE CONTINUED.) Watch Your Jacks Jacks frequently cause great trouble by reason of one' of the contact leaves or springs failing to make contact, or being so closely spaced that a spark discharge takes place. The contact points of the best jacks are made of silver. Atmosphere in a home where small amounts of gas fumes are present will corrode these contacts. Sea or salt air will cause corrosion very quickly during the summer time. Formerly at 39-41 Cortlandt St., New York City. WHOLESALE RADIO SERVICE COMPANY! 9 Church Street New York City NEUTRODYNE SPECIALS Here's your chance to buy the two best known makes of Xeurrodyne Receivers at a real saving! FADA 160 Neutrodyne, Regular Price $120. Our Price $105 FREED-E1SEMANN NR5 Neutrodyne, Regular $150. Our Price, $129.50 WRS NEUTRODYNE for 5 tubes The complete parts for this 5 tube WRS Neutrodyne, all parts Genuine and Guaranteed, including 7x26 Drilled Panel and all other necessaries, $32.50 RADIOLA VI A Six Tube Set This is the Radio Corporation 6 Tube Set that receives over distances up to 2,000 miles on a loop! With an outside antenna transatlantic work is certain. Three stages radio and two audio! In original sealed cases. Regular $275. OUR PRICE $85 Act Quickly! The WRS NEUTRODYNE completely built in a beautiful mahogany cabinet, ready to operate (without tubes or batteries) $59.50 FADA 5 TUBE Neutrodyne in a real mahogany cabinet, ready to operate CCC l\f\ = (without tubes or batteries), onl 20% o We'll give you a discount] of 20% on all merchandise not listed in this adv.l It will pay you to write I COCK AD AY 3 TUBE SET 1 Co'kaday Cci 2 Jefferson Audio Transformers 2 I7-Plate Condensers 2 Switch Arms 1 7x!8 Panel 2 Doubi > Circuit Jacks I Single Circuit Jack 3 Natirnal Sockets 3 Rheostats with Dials 4 Swit'.h Stops I .00025 Mica Condenser I 2 Meg. Grid Leak 16 Ft. Bus Bar 8 Binding Posts 1 .001 Mica Cond. 2 3" Bakelite Dials I 7x18 Ba-e Board Blue Prints and CM Q Cft Instructions <plJ7.au1 REINARTZ 3 TUBE SET I Reinartz Coil I 23 Plate Condenser 3 30 ohm Rheostats 3 Bakelite Sockets I 7x21 Panel 1 7x21 Baseboard 2 Jefferson Shielded Transformers I 2 Meg. Leak Blueprints and 1 .00025 mfd. Cond. 8 Marked Binding Posts 12 feet Busbar Wire 3 Switch Arms 12 Switch Points 6 Switch Stops 2 Double Jacks I Single Jack Instructions $17.75 COCKADAY 4 TUBE SET With Push-Pull Amplifier This is the set that Cockaday described as being able to receive over distances of 3,000 miles. You can't build anything better. .(Parts are those specified by Cockaday.) 1 Cockaday Improved Bakelite Coil 2 Amsco 26 Plate Ver. Condensers 2 Amplex Grid"nsers I Bradleyleak 5 Melco Sockets I Amsco 6 ohm Rheo. 3 Amsoo 20 ohm Rheos. 1 Pacent Single Jack 2 Pacent Dble. Jacks 2 Amertran Trans. I Como Push-Pull Input I Como Push-Pull Output 2 Switch Levers 1 1 Switch Points 2 Switch Stops I Dubilier Cond. .0005 I Dubilier Cond. .00025 I Durham Var. Leak 3 Lavite Resistances, 48.000 I Amsco 400 ohm Potentiometer I 7x24 Panel I 3x2','4 Sub-Panel I 12x12 Panel I 7x24 Baseboard Blueprints, Wire, etc., with each order. $S7.SO COCKADAY 1 TUBE SET The complete parts for this fl*Q QC popular set have been reduced to. . *?*'••'«' Mail orders promptly filled and sent C. 0. D. if you tcish; tee can pay postage on ali orders = over $5,00. In dealing with the Wholesale Radio Service remember that you are buying 1 RETAIL AT WHOLESALE PRICES I SUPER VALUES WHAT'S NEW IN RADIO? SUPER-HETERODYNE Improved Type Write for Prices and Details, for Parts to Build the Finest Broadcast Receiver Known Hazeltines Neutrodyne The ultimate receiver for local and long distance Radio concert reception THE MOST TALKED ABOUT SET OF TODAY 1. SIMPLICITY 2. SELECTIVITY 3. STABILITY 4. DISTANCE 5. NOISELESS (A child can operate it) (You can tune out local stations) (Always ready to entertain) (Average range about 2000 miles) (No squeals, no howls, no whistles) Complete Parts for Building This Master Receiver AS LISTED BELOW, ONLY $49§5 Stock No. 201 A. Quati tity 1 1 5 3 2 2 1 3 1 1 7 Bakelite panel, 24x7x-f;.. drilled 212 A. 213 A. 214 A. 215 A. 216 A. 217 A. 218 A. 219 A. 220 A. 1 1 27 ft. 27 ft. 2 1 1 1 202 A. 203 A. 204 A. 205 A. Grid leak, 2 megohms 50 Grid leak and condenser, .00025 .60 Package screws, nuts, terminals, etc 10 206 A. 207 A. 208 A. 209 A. Fada instruction book 210 A. Fada type 150 A. vernier rheostat 1.25 Eby engraved binding posts 1.40 211 A. $49.65 224 A. 225 A. I 45 volt B batteries $9.00 Set complete aerial equipment.. 2.00 Accessories Necessary to Complete Set for Operation Stock QuanNo. tity 221 A. 5 Bonded tubes $22.00 222 A. I Loud speaker, genuine Baldwin type C unit 12.75 223 A. 4 Columbia or Red Seal A battery 1.60 OUR SPECIAL COMBINATION OFFER To each purchaser of the parts and accessories for the HAZELTINE NEUTRODYNE RECEIVER at the low price of $97.00 we will, without cost to you, ship a Genuine HANES-ZENER special hand rubbed solid $47.35 mahogany cabinet. Value $10.00. Each of the above parts are of the highest standard grade, and carry the HANESZENER guarantee and can be purchased separately at our special prices. Special for This Week Only $ WESTERN ELECTRIC 10A LOUD SPEAKERS List Price, $161.00. Our Price 105 00 Genuine P. L. Original RESISTANCES 48,000 OHMS $1.00 100,000 OHMS $1.00 We Are Prepared to Supply Dealers. Write for Our Proposition. Reinartz Circuit Complete List OUR Price Price Reinartz Coil $2.50 $2.00 One 7xl0x,l Radlon Panel 1.25 1.00 National Bakelite Socket 1.00 .40 Vernier Rheostat 1.50 1.00 Two 23 PI. Var. Condensers at $3 each. 6.00 3.00 Switch Points and Nuts 80 .40 Six Switch Stop Points and Nuts 40 .20 Freshman Grid Leak and Condenser... 1.00 .65 Seven Binding Posts 70 .35 25 Ft. Tinned Bus Bar 50 .30 List Price 3 Switch Levers with Knobs $0.75 One Baseboard for Mounting 75 One Fixed Phone Condenser 40 One Single Jack 1.00 Blue Prints with complete Instructions for assembly and mounting 50 Regular Price $19.05 OUR PRICE $11.05 OUR Price $0.35 .40 .25 .25 .50 All the necessary screws, nuts and miscellaneous small parts which are necessary to complete the set are included in the above prices. Any part in either of these circuits may be purchased independently at the advertised cut prices. COCKADAY Four-Circuit Receiver 3000 MILES Parts as specified by Mr. Cockaday 1 — Cockaday Coil 2 — Amsco 26-Plate Condensers 2 — Amplex Grid-Densers 1 — Bradley Leak, Vi to 10 meg. 5 — Melco Sockets 1 — Amsco 6 ohm Rheostat 3 — Amsco 20 ohm Rheostats 1 — Pacent Single Jack 2 — Pacent Double Jacks 2 — Amertran Transformers 1 — Como Push-Pull Transformer — Input 1 — Como Push-Pull Transformer — Output 2 — Switch Levers 11 — Switch Points 2— Switch Stops 1 — Dubilier Condenser — .0005 1 — Dubilier Condenser — .00025 with Mount 1 — Durham Variable Grid Leak 3 — Lavite Resistances — 48,000 ohms 1 — Amsco 400 ohm Potentiometer 1—7x24 Panel 1— 3"xZi/4" Sub Panel 1— 12"xl2" Panel Our Price $59.00 Erla Two Tube Reflex All Parts for This Circuit $40.70 Including Mahogany Cabinet Parts are Genuine and same as specified by Erla Power Amplifier FOR $19.00 INCLUDING 1 Panel 7x10 1 Cabinet 2 Sockets 1 Rheostat 7 Elby Engraved B Posts 2 Fahnestock Clips 1 Pair Como Push-Pull Transformers List Price, $23.90 We will wire this amplifier for you for an additional charge of $4.00. We Have Just Received a New Shipment of THE NEW MODEL D. N. K. & K. PHONES MADE IN GERMANY Our Price $6.50 WE GIVE A 20% DISCOUNT on All Standard Radio Apparatus Not Listed Above All Mail Orders Shipped Promptly Send Money Order, Including Postage The Radio Mail Order House — Known for Low Prices WRITE FOR OUR CATALOG "B" 1 111 * ifl ^ ss»Jr * 1480 Broadway, Corner 42nd St., New York City