Radio mirror (Jan-Oct 1923)

RADIO DIGEST ILLUSTRATED 15 Questions and Answers Devoted Entirely to Flewelling Fans' Inquiries riewelling Ware tengrth Range 1 170(1) JKQ, St. Paul. Minn. Kindly answer a few questions regarding' the Klewellins supor-resroneralive panel set as shown on page 13 of the December 9 issue. 1. My antenna is a single wire, 100 feet long and 25 feet lead-in. How will this work with the coils mentioned in the circuit? 3, What wave lengths Will this circuit cover, with said coils? 3. For panel mounting; can the primary coil be stationary, arid the tickler movable? 4. With proper primary and secondary coils, would it be possible to receive the Arlington time signals? If so. what size coils would be needed, and what other changes? 5. Have yon anything definite, as to what distance has been heard with this circuit? A. — 1. Your antenna construction is rather long but should be effective with the circuit in question. 2. This circuit should cover from two hundred and fifty to four hundred and fifty meters wave length. 3. Primary coil may be stationary and tickler coil moveable. 4. This circuit is not so effective on high wave lengths, and it is doubtful if you would receive Arlington time signals through it. 5. Generally speaking it has a receiving range of up to one thousand miles, although we have had reception reports as high as two thousand miles. Flewelling for Economy and Bange (1711) HDC, Douglas, Ariz. I was much interested in your article in the DIGEST, which I read with religious regularity, concerning the Flewelling super-regenerative set for the following reason: I am a manual training teacher in a town from 500 to 1,000 miles from any good broadcasting stations. I have a homemade Radio-audio set which receives almost everything between here and Portland, Oregon, Davenport, Iowa, Los Angeles, and Houston, Texas. However, complete with tuhes and batteries it cost about $100 and is beyond the means of most of my pupils. It seems as if this hook-up, used with WD-11 tube, should give distance and volume at little cost. Do you agree with me? Can a variable leak, which would be easy for a boy to operate, be made having a fiber base and an india ink line with switch points, variable with switch? If so, how wide a line, how great a. radius, and how close should switch points be, and how many of them? Will this set receive 500 miles (Los Angeles), 700 miles (Salt Lake), 900 miles (Fort Worth) on a loop? If so, what size? I do not understand how antenna and ground is connected to set. If aerial is used is no ground jsed? A. — We are gratified to hear from you with such kindly expression of interest in our publication in general and the Flewelling circuit in particular. In our opinion this circuit employing WD-11 tube, aa suggested, certainly is worthy of experimentation. Use 100 volts on the plate of this tube. Tour idea of variable leak is good, although we would not trouble with the contact points. Rather make a line scinch wide and 5 inches long on a piece of fiber with india ink, using a sliding or rotary lever on it. The suggested range could be accomplished with a loop, as reports confirm this. A 10 to 12-turn loop, 30 inches on a side, will be satisfactory. For antenna and ground take the two leads which would come from the loop antenna. Usually only one of the two is necessary. Connect to the grid side of the 50-turn coil. Power Amplifier for Flewelling (1739) CBS, Toledo, O. I have a Flewelling super-regenerative panel receiver with single tube as illustrated in your December 2 issue. I have also noted in your December 9th issue, that amplification can be added. As I have a power amplifier and horn, I am wondering if there is any way I can connect this outfit to the Flewelling. If this can be done, I would appreciate a diagram of the filter circuit that should be used in connection with the outfit so as to eliminate the whistle in the set. A. — The power amplifier and horn can be used with the Flewelling circuit as suggested. It would be advisable, however, to shunt a variable leak resistance across the two input binding posts of the power amplifier, which are connected to the phone terminals of the Flewelling panel. Use separate B batteries on the power amplifier, although the A battery can be common. Transformer Connections (1740) HA, Tampa, Fla. I am. going to try out the "one lung" Flewelling circuit. I notice in your description of the amplifier (audio) for this set you connect one end of transformer secondary to positive side of filament instead of negative side. Why is this done, or is it immaterial? Nearly all hook-ups connect to negative side. I note also that positive side is specified in Mr. Flewelling's telegram. I note that positive side of A battery is used throughout instead of negative as per usual practice. I do not want to belong to the five per cent who do not get results with this circuit so I am. trying to get right before I start. What effect does a grid condenser of too large capacity have on signal strength? A. — It is immaterial which method of connecting audio transformer to filament is employed, although It might be well in executing any circuit to follow the details of its originator. A number of hard tubes will be found to give better results when connected as shown. A grid condenser having too much capacity will have a choking effect on received signals. Tin Pan Music (1737) FW, Detroit, Mich. I put up a Flewelling circuit and it works fine on WWJ and WCX, which are only one-half mile from me, but when their concert is over and I try for long range I get Atlanta, Kansas City, Newark, Chicago, New York, Minneapolis, Pittsburgh and Schenectady, but the signals are mushy. I can hardly understand them as the music sounds like some one pounding on a tin pan. I intend rewiring it again and using two steps of audio frequency amplification and also a crystal detector so I can receive WWJ and WCX on the crystal. Would you please send me a diagram of the Flewelling circuit, with a crystal detector and also two stages of audio. I would like to have it drawn so I would have a jack for the crystal, one for the detector and a jack for each step of audio; four jacks in alL I want to use one A battery and two B batteries, 100 volts for Flewelling and 100 volts for audio amplification. My aerial is in a nest of telephone and high tension power lines, but I have it running at right angles with the power lines. Would this help to make my signals mushy? A — Having constructed your antenna at right angles to high tension lines there should be no interference from this source, the mushiness of signals indicates an incorrect value in grid leak. This may be determined and overcome through experimentation. Use the best variable grid leaks you can make or buy. RADIO SUPPLIES STORES Prompt Serriee— Qualify Goods— Priced Righi Radio Division TELEPHONE MAINTENANCE CO. 20 S. Wells St. Franklin 3986 5206 V. Madison, Austin 7041. 1122 t. 47th St Look for the TELMACO Sinn A crystal detector would not function In the circuit you are employing. A diagram showing two stages of audio frequency amplification for the Flewelling appears on page thirteen of the December 9 issue. This will be helpful to you. Kind of Tubes to Use (1744) GWK, Hope, N. D. In the December 2 DIGEST, page 13, you give the Flewelling single-tube set saying to use a hard vacuum amplifier tube. Now, on page 13 of December 9 issue you say to use two amplifier vacuum tubes. Then in the reading of it, you say the elimination of the whistling must be accomplished through the detector circuit. Now what I want to know is. do I use three of the same tubes to make a twostage audio frequency amplifier? Let me know if you use a detector tube and what kind of tube it is. Could I use a variocoupler in place of the honeycomb coils? A. — In the Flewelling circuit hard tubes should be used throughout for both detector and amplifier. The employment of a variocoupler instead of honeycomb coils will be entirely practical. GOVT RADIO STORAGE BATTERIES All absolutely new Signal Corps Batteries. Edison 3 cell type BB-4 $4.50; Wlllard i cell type SYR-13 $4.25; Willaxd 2 volt 40 A. H. for WD-11 tubes $4.75; 6 volts Edison $7.75; Edison B battery elements 4e each. FLEWELLING .006 CONDENSERS Bakelite mounted with bindin&r posts. Set of three $2.90. Variable Grid Condensers .00025 or .0005 max. 45o. FLEWELLING SPIDER WEB COILS Easier tuninir; clearer signals; green 8i-Dr wound $1.75 each. FLEWELLING VARIABLE GRID LEAKS Give clearer music, louder signals on any circuit, 75c. REINARTZ LATEST SPIDER WEB COILS Double green silk winding on Bakelite spider $1.05. Choke coils for Beinartz detector plate circuit $1.70. VERNIER FOR VARIABLE CONDENSER Pits any condenser. Bequires no extra space, 95c. HI-POWER AMPLIFYING TRANSFORMERS Best made. Louder signals. Cannot burn out $2.95. Jacks. Open circuit .48: Sin. ctr. .54; Doub. cir. .62; Plugs .56 ; 3000 meter long wave couplers $7.95. We save you money. Tell us what you need. Include Postage With Tour Order QUALITY RADIO SHOP, RICHMOND, IND. "ALL-AMERICAN" Amplifying Transformers Two years of successful use all over the world, guarantees permanent satisfaction. Radio and Audio Frequency. SEND FOR CIRCULARS RAULAND MANUFACTURING CO. 35 South Dearborn Street Chicago Carter "TV -WAY" Radio Plug take two head sets and all types cord tip terminals. Price $i.lo. Write for Bulletin on Carter "HOLD-TITE" Jacks and other products. CARTER RADIO COMPANY, 209 South State Street, CHICAGO ATWAT KENT Immediate Delivery Dealers: Write for Discounts Hudson-Ross, 123 W. Madison, Chicago Mounted 3 Circuit Tuner Exceptional selectivity and sharp tuning, makes the most easily constructed and highest efficiency Set known. Price without dial $6.00 With 3% Bakelite Dial $7.00 Our VARIABLE CONDENSERS, VARIOMETERS, 180 DEGREE VARIOCOUPLERS and AMPLIFYING TRANSFORMERS represent maximum workmanship and efficiency at absolute MINIMUM prices. NEW YORK COIL COMPANY 338 Pearl Street NEW YORK CITY, N. Y. -Wessco W. E. SUPPLY AND SERVICE CORPORATION 18 MURRAY STREET, New York 2 Blocks South of Chambers, between Broadway and Chnrcht St. OUR PRICES SPEAK LOUDER THAN WORDS FREE FREE FREE WITH EVERY $10.00 AND OVER PURCHASE A $1.50 32V2-VOLT VARIABLE B BATTERY Mail orders must include postage. TERMS:— Money Orders with Orders— checks not accepted. All Merchandise offered is Standard, Guaranteed, and is o£ perfect workmanship. PRICE Complete "Bette* Than The BestT Made Good in a Night INCLUDING PHONES, TUBES, AERIAL and BATTERIES SOCKETS: $1.00 Genuine Bakelite Socket $ $ 1 .00 Sockets $1.00 All Moulded V. T. Sockets DIALS: $1.00 Genuine Bakelite Dials — 3-ln., 45c; 4-in .55 VARIOCOUPLERS: $7.00 Guaranteed Genuine Bakelite Pioneer Variocoupler. silk wound 4.75 $4.25 Variocoupler, guaranteed high Quality 2.25 $8.00 Moulded Variocoupler. highest quality 4.50 $5.00 Shamrock Variocoupler 2.59 TRANSFORMERS : $5.00 Acme Transformer 3.40 $3>00 Radio Frequency Transformers 1.65 $6.50 Wessco Audio Transformers, highest quality guaranteed 3.25 VARIOMETERS: $6.50 Pioneer Variometer, Genuine Bakelite silk wound 4.50 $6.60 Wossco Variometer, highest quality guaranteed 3.25 $4.50 Variometer, guaranteed high quality. 2.40 $6.50 Moulded Variometer, highest quality. . 3.50 BATTERIES: $8.75 Westinghouse Storage B Battery 4.75 $24.00 A Battery, 100 Amp.. 6 V 16.75 SI9.00 A Battery, 20 Amp., 6 V 11.75 $14.50 A Battery. 60 Amp., 6 V $3.00 Battery, 22'/2 V. Variable, highest quality guaranteed. Large size $1.75 B Battery. 22'/2 V. Variable, highest quality guaranteed. Small size CONDENSERS: $5.00 23-pl. Variable Condenser $5.50 43-pl. Variable Condenser 3plate Vernier Variable Condenser 50c Mica Condensers Thordarsan Grid Condenser Bronze Bus Bar, tinned, ft $25.00 MIRCLE CRYSTAL 8.75 1.45 .75 1. 05 1.05 .70 .25 .15 .02 PANELS: Guaranteed Genuine Bakelite Panels — 7x10, $1.25; 7x18. $1.85; 9x10. $1.60: 5x5, 47c; 5x9, 95c; 8x12, $1.25; 7x12, $1.50; 7x9. $1.15; 12x14. $3; 7x24 $ $1.50 Microstats . — Spaghetti, per length PHONES: Special Electric Soldering' Iron, 2 heats 20o Bezel $3.00 Brandes Phones $8.00 Dreyfuss Phones $5.00 Murdock Phones $1.00 Freshman Variable Grid Leak WIRE: U00 ft. coil No. 14, 7-strand pure copper Aerial Wire Magnot Wire 20 per cent, off list. RHEOSTAT: $1.50 Thordarson Vernier Rheostat $1 .00 Rheostat Hnmecharger De Luxe Ichns-Manvilfe Blk. Com. Tubes, 3-in.... DETECTORS: 5 .75 Crystal Detector $ .40 K. D. Crystal Detector . $150 Mutti Jack SI. 50 Twin Adapter $1.25 Universal Plug BATTERY CHARGERS: $18.00 Westinghouse Battery Chargers $19.50 Westinghouse Battery Chargers for A. &. B. Batteries 70c Open Circuit Jack 85c Double Circuit 75c Battery Hydrometer KNIFE SWITCHES: Knife Switch S. P. S. T Knife Switch S. P. D. T Knife Switch D. P. D. T Wooden Horn Contact Points 3.00 .85 07'/z 4.95 .15 5.75 6.00 3.55 .75 .50 1. 10 .32 13.25 .25 .35 .16 1.15 1.15 .75 13.25 16.00 .40 .45 .35 .14 .22 .35 6.00 .06 RECEIVING SET WITH 3000 OHM PHONES, 100 FT. AERIAL, 2 CLEATS AND POR. TUBES, $7.95 MAGNAVOX— NEW TYPE, NEW CONSTRUCTION, NEW FINISH $32.50