804 Power the Radio Experimentir's Magazine

'OR_ WAV (RAFT

i How to Build The 804 POWER Oscillator See Page 13 6 THE RADIO EXPERIMENTIR'S MAGAZINE www.americanradiohistory.com THE 72eu, DOERLE 6 -TUBE BANDSPREAD RECEIVER Marvelous SENSITIVITY and SELECTIVITY Only Found in the Higher Priced Models

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www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 129 Sicly EEL LoWS

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www.americanradiohistory.com IN THIS ISSUE: PROMINENT SHORT -WAVE AUTHORS Parsons Schrage Shuart Cisin Palmer Hooton

H. WINFIELD SECOR Managing Editor HUGO GERNSBACK GEORGE W. SHUART, Editor W2AMN Associate Editor

Combined With r Official SHORT WAVE LISTENER Contents for July, 1936 Certified Circuits SHORT WAVE CRAFT goes Editorial -"What Interests Me Most in Short Waves," by Hugo Gernsback 131 to a large expense in verify- Short Waves iq War and Peace 132 ing new circuits. When you see New TELEVISION Experiments by RCA, by M Harvey Gernsback 133 this seal it is your guarantee Details of HAM Sets That Will Flash Yacht Race News 134 that such sets have been tested He Talks Through his Hat -and Gets Paid for It!, by W. E. Schrage 135 in our laboratories, as well as 804 Power Oscillator (Cover Feature), by George W privately, in different parts of Shuart, W2AMN 136 What Does It Cost to Become an Amateur ?, by Howard the country. Only "Constructional -Experimental" S. Pyle 137 circuits are certified by us. "Turnstile" Antenna Array at W8XH 138 Can 5 Meter Waves Extend Beyond the Horizon?, by When you see our certified seal on any set de- D. R. Parsons 138 scribed, you need not hesitate to spend money for New Ultra S -W Tuner Has No Coils 139 Cathode -Ray Tube Tester 139 parts, because you are assured in advance that the 400 Megacycles Used by French "Hams ", by C. W set and circuit are bona fide and that this magazine Palmer 140 The All -Wave "AIRCRAFT 3 ", by H. G. Cisin, M.E 141 stands behind them. 1 Tube -1 Crystal-4 Bands! 142 SHORT WAVE CRAFT is the only magazine that 2 -Volt Short -Wave Superheterodyne for "FAN" or "HAM ", by Harry D. Hooton 143 certifies circuits and sets. 5 and 10 Meter Crystal Transmitter, by George W Shuart, W2AMN 144 Short Waves and Long Raves -Our Readers Forum 146 World -Wide Short -Wave Review, by C. W. Palmer 147 $5.00 for Prize -Winning "Kink" 148 OUR COVER Short Wave Scouts -Twenty- Eighth Silver Trophy Award 149 The cover feature this month illustrates a radically new What's New in Short -Wave Apparatus -5 Meter Trans- Transmitter, employing the latest in tubes -the 804 mitter and Receiver Portable, by Irving Rosenburg, power pentode. This tube is used as a high- power, crystal - W2CQI 150 controlled oscillator, and it is completely described on page The RX -14 S -W Receiver for "Fan" or "Ham ", by Guy 136. Stokely, E.E. 151 The "Transceptor ", by Frank Lester, W2AMJ 151 New Apparatus for the "Ham" 152 New 5 -Tube A.C. -D.C. Super -Het Has Dual Range 152 COPYRIGHT. 1936. BY H. GERNSBACK The New Hammarlund "Super Pro," by Donald Lewis 153 The Radio Amateur Course, Conducted by Geo. W Published by POPULAR BOOK CORPORATION Shuart, W2AMN 154 HUGO GERNSBACK, President - - - - H. W. SECOR, Vice- President Short Wave League and Scout News 156 EMIL GROSSMAN Director of Advertising World S -W Station List, by M. Harvey Gernsback 157 Chicago Adv. Office L. F. MCCLURE, 919 No. Michigan Ave. Alphabetical List of S -W Stations 161 Publication Office 404 N. Wesley Avenue. Mount Morris. III. Short Wave Question Box 162 Editorial and General Offices - - - - 99 -101 Hudson St.. New York. N. Y. Gerald D. Coleman Station 164 European Agent: Gorringé s American News Agency, 9A Green St., Leicester Square. London W. C. 2 A sIr li n Agents: MrG11.L'S AGENCY. 179 Elizabeth St., Melbourne Features in the August "Fan" Issue A Midget "FAN" Receiver, Using 4 Metal Tubes, by H. G. SHORT WAVE CRAFT -Monthly. Entered as second class matter May 7, 1930, at the pont office at Mount Morris, Illinois, under the act of Cisin, M.E. March 3, 1879. Trademarks and copyrights by permission of H. Gerns- A Transmitter using the new "Beam" Tubes; All Bands back, 99 -101 Hudson St., N. Y. C. Text and illustrations of this magazine are copyrighted and must not be reproduced without permission. SHORT with One Crystal, by George W. Shuart, W2AMN. WAVE CRAFT is published on the let of every month. Twelve num- A Proven 5 -Meter Super -Regenerator. bers per year. Subscription price is $2.50 a year in the United State. and possessions and Canada. Foreign countries. $3.00 a year. Single How to Experiment with New Circuits, by Willard L. copies 25e. Address all contributions for publication to Editor, SHORT Miles. WAVE CRAFT. 99 -101 Hudson St., New York. N. Y. Publishers are not responsible for lost manuscripts. Contributions cannot be returned unless Radio is 100 Years Old!, by H. W. Secor. authors remit full postage. SHORT WAVE CRAFT is for sale at all All principal newsstands in the United States and Canada. European agents: -Band Transmitting Doublet -How to Make and Tune Brentano 's, London and Paris. Printed in U. 8. A. Make all subscrip- It. tion checks payable to Popular Book Corporation. 130

www.americanradiohistory.com HUGO GERNSBACK, EDITOR H. WINFIELD SECOR, MANAGING EDITOR

H(} Lc DO 0000 "What Interests Me Most in Short Waves" The Results of Our Fifty Dollar Prize Contest By Hugo Gernsback IN our last February issue, we announced a prize contest First Prize Letter, by William Cusick based upon the question: WHAT ARE THE TEN THINGS IN SHORT WAVES 1. Amateur Transmitters -I am interested in the type THAT INTEREST YOU MOST TODAY? of transmitters which can be built at a moderate price, and The idea behind the prize contest at the same time, are efficient and was that we wanted to ascertain not not really "flea- power" for example, My interest only for ourselves from an editor- in $50.00 the "SG3 transmitter." ial viewpoint, but for our readers WINNERS is due to the fact that I expect to put themselves, exactly wherein their a "rig" on the air soon. greatest interest in short waves PRIZE LETTE R CONTEST 2. Short Wave Sets-I am inter- lies. ested in A.C. receivers using four or It was realized that the short- First Prize Winner-$20.00. five tubes. I build this type of set wave art today embraces many William Cusick, 431 S. Locust, Ottawa, because I have found it is very effi- fields of endeavor, which are be- Kans. cient; is economical to operate; and coming more numerous as time Second Prize Winner-510.00. the cost of building is low. This low goes on. New discoveries are made Allan E. Vosburg, Jr., 5247 Larchrnont cost enables me to build several sets almost weekly in which the instru- Ave., Detroit, Mich. at the same time, each using a dif- mentality of short -waves play a Third Prize Winner- 55.00. ferent idea, and compare the results. and it was therefore of interest Carl E. Swanson, Waverly, Nebr. part, Fourth Prize lVinuer- 53.00. 3. Television -I am interested in to know just how our readers felt Television because it will only be a the art of short -waves in gen- William Roberts, 268 Gardner St., Ply- about mouth, Pa. matter of time before it will be in eral. use in every home, just as radio is responded in no un- Fifth Prize Winner-S2.00. Our readers Horwath, Jr., 936 N. Keystone today. My first view of a television certain tones. Several thousand en- Louis picture gave me the same thrill as were received from all over the Ave., Chicago, Ill. tries Sixth to Fifteenth Prize Winners, In- the first time I listened to a broad- world. The outstanding points about cast on the old -time "crystal set." that in the main, clusire-51.00 Each. the contest were, W9AEA, 2659 Na- 4. Antenna Systems am con- most readers agreed on what interests Merrill Lindley, -I there were at least six sub- poleon St., Indianapolis, Ind. tinually experimenting with short- them and F. Hooton, Arlee, West Va. wave antennae; your articles on this jects which were virtually duplicated Carl astonish- John T. Kelly, 778 -7th St., San Pedro, subject are very helpful. I am in- in all of the letters. This is terested in this subject because I ing and at the same time very illu- Calif. show that the Marion L. Mizer, Milton, Ore. I have found that a receiver is im minating. The letters P. J. Bester, 85 Main St., Somerset better than its antenna, and I am readers of Short Wave Craft possess C. of what is go- West, So. Africa. sure this is true for transmitters an accurate knowledge Leo J. Vince, 2805 E. 117th St., Cleve- also. ing on in short waves. Indeed, most of the con- land, Ohio. 5. Ultra -Short Waves -Reception the answers showed that Sound, Ont., below 5 meters in- testants were excellent students of Leslie A. Croutch, Parry and transmission but few of them are Canada. terests me because, due to the fact the subject and Adam Mazan, R.D. 4, Box 75-A, that present radio channels are over- onesided in their endeavors. This is least Short Wave Latrobe, Pa. crowded, it seems to me that the as it should be-at I. E. Harper, 1218 No. Adams St., Ma- solution will be the future use Craft has always made it a point to logical art from every son City, Iowa. of waves below 5 meters. cover the entire C. Hansen, 3156 So. Illinois Ave., Mil- 6. Short Wave Diathermy am angle, and this we are happy to say -I the letters of waukee, Wisc. interested in this phase of short y has been reflected in waves because it seems to me to be the contestants. one of the outstanding developments We reproduce here the entries of and third prize -winners. We take this occa- of short waves. If short waves can bring about a cure for the first, second, miracle will have happened. sion to congratulate the winners, as well as all contestants disease, 'another high quality of the entries in this con- 7. Airplane Radio -This branch of short waves interests upon the uniformly founda- (Continued test. We regret that only three letters can be printed. me because it is really the on page 170)

SHORT WAVE CRAFT IS PUBLISHED ON THE 1st OF EVERY MONTH

This is the July, 1936 Issue -Vol. VII. No. 3. The Next Issue Comes Out Jul. 1

Editorial and Advertising Offices, 99 -101 Hudson Street, New York City 131

www.americanradiohistory.com 132 SHORT WAVE CRAFT for JULY, 1936 Short Waves in War and Peace Short -wave equipment played an important role in the sip a advance of the Italian Army in Ethiopia. The Hindenburg, Germany's newest dirigible, found short wave valuable while flying the Atlantic.

4.,74 '04414,

Above -Italian Artillery unit using portable snort -wave net for the purpose of locating the enemy's position. Some of these sets are operated by battery power, while others derive their power from dynamos driven by foot- power, similar to the pedals on bicycles.

----- ...... _ .

Top li n prcinhle uhe -pnr I, .1i rt -n.n, -c.t in use by members of the Italian Army Signal Corps. The men in the upper photo are shown receiving a short -wave message from field headquarters. The photo just above shows still another type of short -wave transmitter and receiver carried by the Italian Army in Ethiopia.

Photos below show radio equipment aboard the "Hindenburg." giant German dirigible. Short waves play a very prominent part in keeping the huge air- ship in touch with important land stations.

Fig. 1 shows interior of the radio station aboard the " Hinden. burg." At left. SW transmitter with range of 15 to 75 meters. Two ten ter cabinets contain receivers with range of 15 to 20.000 meters; the cabinets are airtight and water - proof. At right, transmitter with range of 600 to 2.700 meters. CW or phone. Fig. 2 shows "blind landing" indicator be- side steering wheel of the "Zen." which connects with the special receiver In the Navin.. try tins Room in Fig. 4. Fig. 3. stream -lined rounter-weIghts keep the antennas taut.

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 133

CAT1400E RAY TUBE "IMAGE " PICK -U P IMAGE CAMERA AND SOUND TRANS- FOCUSING DEVICE MITTED ON DIFF- ERENT FREQUEN- CIES

in outdoor scene. The cut -out in the wall shows the control room and transmitters actually lo- Technique employed televising the studio is shown. cated in an adjacent room. Arrangement of lights, camera, and subject when televising a person in EXPERIMENTSTS NeW BY CRCA side of LAST month a group of radio editors By M. Harvey Gernsback bands extend 1% mc. on each to the RCA research lab- the carrier or a total of 3 mc. The was invited 343 lines. Scanning is oratories in Camden, N.J., for a demon- A very interesting demonstration of the pictures contain done 30 per second. stration of the latest experimental new RCA Television System was recently at pictures de- The television camera resembles a "home" type television receiver given at Camden, N.J. Images of outdoor ex- workers. up and the sound was commercial photographer's camera, veloped by RCA research scenes were picked instead of having a sensi- Scenes televised at the transmitter, a also transmitted and received. Even cept that were are used tized photographic film inside it, there mile away from the receiver, though two different frequencies tube for pick- although they suf- the voice and image, the receiver is a special cathode -ray clearly reproduced, to carry ing up the images and converting them fered from occasional blurring. Sev- has but a single tuning dial. car- eral of the radio editors were persuaded into electrical impulses, which are to appear before the television "camera" ried by wire to the radio transmitter. recognized by The camera has an adjustable focus and were clearly seen and Autos passing by on the Delaware of an oper- their colleagues when the images were River Bridge, several hundred feet and requires the presence which was ator to adjust the lens for various dis- reproduced at the receiver, from the "camera," could be seen as being televised housed in an attractive console cabinet, well as the activities of the fire -fighters tances as the subjects similar in appearance to one housing who were about 50 feet away. To con- move about. a modern phono -radio combination. clude the demonstration a one -reel mo- Receiver Details Their voices were also heard as the tion picture was televised. This also of system makes use of sight and sound came through very well. The receiving equipment consists this the Camden Fire two separate receivers of the super- channels. After Cathode Ray System Employed heterodyne type, operating from a 110 Department gave a fire -fighting demon- supply. Both stration on a building adjacent to the The cathode ray method of scanning volt, 60 cycle A.C. power- was is employed in the RCA equipment. receivers are in one cabinet. The re- studio. The television "camera" mc. moved to an open window and picked Two ultra -short wave transmitters are ceivers will tune from 40 -80 up the scene for the "viewers" at the employed, one for sight on 46 mc. The cathode ray tube is mounted ver- receiver. This sunlit outdoor scene was and one for sound accompaniment on tically in the cabinet, with the end reproduced with remarkable clarity. 48 mc. The television transmitter side- where the (Continued on page 173)

VOICE AND IMAGE LF AMP. 2ND. MIRROR RECEIVED ON TWO B 3/4 T09 MC. DEI. SOUND CATHODE DIFFERENT FREQUENCIES RAY TUBE MAIN BROAD TUNING DIAL COMMON (VISION AND 1LT. DEI. SOUND) s.

MIRROR CATHODE RAI TUBE AUX. CONTROL MAGNET COILS USED AS PART KNOBS OF CATHODE-RAY CONTROL SYSTEM. THIS UNIT IS IN CABINET Ard '136' CHASSIS ras EVa LiEÍ C

TUNER SPEAKER (PRESELECTOR) COMMOÑ F. AMP. 2ND \ AF OSCILLATORS , COMMON OSCILLATOR to TO 11Y2 MC OET. AMPLIFIER TO CAUSE BEAM 1 TO SET TO SCAN POWER SUY &OPPL SC.,ETC. - FRONT VIEW -

Block diagram of the sight and sound ultra short wave receiver employed in latest television demonstration. Note the common first detector -oscillator system and separate I.F. amplifiers for sight and sound. Sketch of console for sight and sound receiver appears at the right.

www.americanradiohistory.com 134 SHORT WAVE CRAFT for JULY, 1936 Details of HAM Sets That Will Flash Yacht Race News

In the last issue we described the "general plan" for reporting the sail -boat races on Long Island Sound this summer by a network of "Ham" stations. A description of the 5 -meter Transmitters and Receivers to be used in this "net" is given herewith.

THE general plan of operations whereby a network comprising 5- meter "Ham" stations, some of them on land and others located on sailing yachts, which will be used to report the positions of the boats during the races, was described in the last issue. In the present article a description is given 56 me. Transmitter, with microphone and of a typical 56 mc. transmitter to be batteries, of the type to be used by "clam" used for making these reports over stations in reporting the yacht races on "Ham" phone channels. The particular Long Island Sound. transmitter shown was designed and built by the technical committee of the Garden City Radio Club of Long Island. one of the most ambitious ever at- The transmitter is very compact and tempted by the "Ham" fraternity, has is entirely battery- powered. Either been worked out by the Garden City voice or I.C.W. may be used. This high . Radio Club. frequency transmitter employs three The transmitting equipment not only 6A6 tubes; one as an oscillator, one as had to be light and portable but it also a modulator driver, and the other as a had to possess the quality of reliability Class B modulator. In the top view of and be sufficiently powerful to insure the transmitter, the shield cans at the unbroken communication under practi- back cover the microphone and Class cally all conditions. The transmitters B input and output transformers. The and receivers will be of the separate unity coupled inductance and tuning type, so as to avoid any Q.R.M. which condensers are mounted on a strip of is frequently created by the use of 56 Victron. mc. transceivers. There will also be As described by Stanley P. McMinn frequent need for duplex operation. of the Garden City Radio Club in the The accompanying photos and dia- New York Sun, the plan in brief is to gram give the reader a clear idea of the maintain contact between the sailing 56 mc. transmitter, as finally worked yachts in the various races and also out by the technical experts of the between the yachts and their home G.C.R.C. The transmitter is built into yacht clubs. The details of the plan, a National S -W -3 metal cabinet meas-

ANT 2 TURNS, 21/2 0.0. UNITY I" COUPLING COIL CLASS BINPUT /646 M KE - MFG CLASS.B OUTPUT 646 INPUT o 2 o Photos above show :25- close -up and chassis MG views of the 56 mc. transmitter. 15 A K .--. M MF - 5MF.r-C 6A6 uring 9" deep, 91/2" wide and 7" high. 1000 On the front panel ONMS there is the Na- tional midget tuning dial, a 0 -150 milli- >' MIGN- 150 K K RFC 2 FREQUENCY MAS IMF. ammeter, a high frequency buzzer for BUZZER OOO1 ICW work, switches for the filament STAND-BY `SW. s,000 5w. and B supplies and two jacks, one for ONMS 4wIRE ice--'- the microphone and the other for the CABLE 'B+ f ` (B_ _ CA+ (KEY MIKE key. The handles were added in order to facilitate passing the rig around Wiring diagram of the 56 mc. Transmitter, of the type shown in the photos above. from ship (Continued on page 169)

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 135 He Talks Through His HAT -and Gets Paid for It! New "Silk- Hat -Transmitter" of the NBC which operates on a frequency of 270,000,000 cycles with an output of 2/10 watt. By ULTRA SNORT WAVE ANTENNA E. TRANSMITTER HOLLOW ALUMINUM W. Schrage WAVELENGTH 11MEIER ROD 61/2 "IN HEIGHT George Hicks, popular N.B.C. announcer wearing the latest style 1 -meter transmitter "hat" by means of which he transmitted descriptions of the Nie SILK "Easter Parade" on Fifth TOP HAT .Avenue, New York City, to the N.B.C. network. etweNewANOwNe HANDP tried to utilize a tiny MIC transmitter like this for their program features. The large dimensions of the "knapsack" sets used did not permit the announcer to move about freely in large crowds. This disadvantage of course reduced the entertainment value of these SWITCH "spot- pickups," since the Ai 6vOLT BATT. by- standers became "mi- SWITCH HEATER CUR- RENT FOR crophone- conscious" and TUBES on BATTERY OF SO VOLTS MICROPHONE AMP- the interviewed "man FEEDS 'NE TRANS- LIFIER AND MOOULATOR MITTER WITH the street" became in- STAGE OF THE TRANSMITTER. fected with stage- fright ELECTRICAL POWER. and he gave a very poor This diagram shows the various coin performance in conse- ponent parts of the 1 -meter transmitter the batteries for operating it being car TO EXTEND the scope of pick -up NBC STUDIOS 10 NETWORK »-- B.C.WAVE TO STATION TMOUSANOS vied on a belt around the waist. for present broadcasting networks, ALL OVER o. COUNTRY and to enable "foot- loose" radio re- WEAF TRANS. sible, and we shall have to watch out porters to carry a small microphone to fi !METER WAVES that any point desired, O. B. Hanson, chief Tß ï for the "secret radio reporter," who may, National Broadcasting AVES, perchance, sit on a chair next to us, and engineer of the transmit everything we say to our friends Company recently designed a very in- 1 teresting miniature transmitter, oper- in the radio audience, thanks to the new TELEPHONE 1 meter short -wave "silkhat" set. ating on a wavelength of about 1.1 CIRCUIT meters (about 270,000,000 cycles per The actual possibilities for "secret short CAR EQUIPPEO pickups" as sketched above, have been second). The output of this ultra WITH TRANS. AND RECEIVER proven by actual experiment by the transmitter is about two -tenths 11 N.Y. CITY ware well -known NBC announcer, George of a watt, and the with his "silk -hat" is A 1 -meter receiver Hicks, who walked range covered LI' 5TURNS BARE COOPER ANT mounted in an auto- along Fifth Avenue on be WIRE NE. SO. COIL MAN. transmitter estimated to WINNER mobile picked up the OUTSIDE .B" x YB "LONG morning, hiding under his cut- about one -quarter HIGH voice of the an- Easter G nouncer as he walked away of formal fashion a wide leather of a mile. This 955/ G-15MMF has along the avenue; in belt containing the "power- plant" of transmitter turn it was trans. the tiny broadcasting station. A pocket - been installed in L2 L!) mitted from the car 1 connected through the crown of a on another w a v e- size microphone was i length to a receiver an inconspicuous looking cable with the top hat and silk located in N. B. C. power -plant, and the silk -hat trans- has a weight of 1 headquarters in Radio City. mitter completed the outfit. The only only 11 ounces! Cl. 0-ßMMF -100MMF1 Diagram at left. unusual accessary for a fashionably The main trick O17 shows how the acorn RI MMF Easter parade visitor was the in building this tubes were hooked up dressed 10.000 TRIMMC3ER hollow aluminum rod, 6% inches in miniature broad- OHMS CONO. in the 1 -meter transmitter carried by the length, fastened atop the silk -hat, and casting station announcer. -wave lies in the use of operating as a so- called quarter B SV ¡ 955 antenna. extremely small BAT` TRANSNS radio tubes, well I The antenna can also be made in- known to ama- quence. conspicuous by using a blackened piece teurs under the The experiment of thin steel wire. Since the range of such a small transmitter hardly extends name of "Acorn" L-_- J during the last tube s, because MICROPONE Easter Parade on beyond a quarter mile, the automobile resemble an Fifth Avenue, pickup and transmitting station which they and relayed (on a longer wave) acorn in shape 90v. `- 6V. New York, has received and size. It is shown that un- the "voice" of Mr. Hicks to the broadcast studio, will of course be necessary TURNS N? !O BARE limited tricks of first time 4 COOPER WIRE , not the L2. I that broadcasting /13'13i1 FORM "broadcast report- for secret "spot" pickups in the fu- stations have 4 IS '/a " DIA FORM ing" are now pos- ture. But who (Continued on page 181)

www.americanradiohistory.com 136 SHORT WAVE CRAFT for JULY, 1936 How To Build the Very Latest -The 804 Power Oscillator

This photograph clearly shows the general layout of the 804 power oscillator. THOSE who read the article describ- last month. Over 200 watts can be ing on the 40 -meter tap, the coil functions the 830 -B amplifier in last obtained from the 830 -B's in this com- with a 40 -meter crystal and operation month's issue, will recall that we men- bination and, needless to say, it is an to be obtained tion the use of on either the 40 or 20- an 804 driver. The idea extremely simple combination of appar- meter band. On the last tap, the 20- worked, out so well that we thought it atus and very economical to build. meter tap, we would be use a 20 -meter crystal advisable to describe the unit In the tritet circuit we have a tapped, and obtain considerable output on either in detail. dual-wound filament coil consisting of the 20 or 10 meter bands. The 804 is, as many already know, an 28 turns of No. 16 double cotton cov- addition to the now tremendous line of ered wire. These two wires are laid Works on 10 Meters Too! R.C.A. Radiotrons. This new tube has side by side and wound on a 11/4" Bake- Those who many are interested in 10- meter capabilities in so far as the ama- lite coil form. One of these windings transmission will find this oscillator, in teur is concerned ; the tube itself may is tapped at the 10th and 2nd turn from conjunction with one of the new Bliley be used as a complete crystal -controlled the filament end. When the switch is 20 -meter crystals, to provide an excel- transmitter and with an output of opened the coil functions with an 80- lent driving unit for a pair of fairly around '75 watts. It will stand up to meter crystal. In this position, and high -power, ultra -high frequency tubes. 1,250 volts on the plate and has a 7% with an 80 -meter crystal, considerable In a circuit of this type, where we are volt filament. It is exceptionally well output can be obtained on either the 80 operating the crystal in conjunction constructed and shielded; so well shield- or 40 -meter band, merely by adjusting with a fairly high -power oscillator, it ed, in fact, that there is hardly a trace the plate circuit to those bands. Then, is necessary to the of reaction between the output circuit keep tuning capacity and the crystal when the two are 2.5 PAN. resonant at the same frequency. 8041 ( TOP VIEW OF SOCKET SHOwN) The unit as shown in the photo and R. F. C. the diagram is the well -known tritet circuit and can be used as we said before, either as a complete transmitter having an output of around 75 watts, 250 ---. or as a driver for a high- powered ampli- MMF. fier. In fact, this tube with full plate input should be capable of supplying excitation for more than one -half kilo- watt amplifier. The oscillator shown as 0 -50 in the diagram was operated separate- 10,000 MA. ly for a number of evenings on each of OHMS M the three prominent amateur bands and provided a surprising number of "contacts." This outfit really demonstrated 1 that an efficient transmitter can be built with a minimum of parts. 250 7 MMF. Ideal for Use With 830 -B Amplifier 30,000 When used in conjunction with the OHMS 830B push -pull amplifier, only 750 volts were applied to the plate. Even this moderately low plate- voltage provided more than enough output to excite the 830 -B amplifier when the plate circuit of the 804 was tuned to the second har- 1ÑAM monic of the crystal. We can think of no finer combination as a medium -power 0,1 transmitter than the use of the 804 in a tritet crystal -oscillator circuit, as 7.5V. B+, 45V. B+, 750-1,000V. described in this article, and the 830 -B Diagram push -pull amplifier of the crystal- controlled high -power oscillator. Tapped coils are used to which was described change hands.

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 137 Described By Its Designer George W. Shuart W2AMN

In this article the new 804 power pentode is used as a high -power crystal -controlled oscillator. The unit as described may be used as a flexible transmitter, just as it is or, as originally suggested by the author, it may be used to drive the 830 -B amplifier described last month. Another view of the oscillator, clearly showing the double -wound filament coil. across the filament coil quite large. We We are not so much concerned with used in order to keep the R.F. where use a 250 mmf. condenser and the plates the capacity in the circuit on 80 meters, it belongs. The filaments are by- passed are nearly full meshed for each of the because the tube is operating very effi- on the transformer side of the coil with respective positions of the switch. ciently at that frequency. However, two .001 mf. condensers. Low "C" in a circuit of this type is the variable tap when operating on The screen, suppressor and plate are liable to result in high crystal current either 40 or 20 meters, should include also by- passed with .001 mf. condens- and, as a result, a fractured quartz as many turns as possible, making an ers. For low -power output where the plate. In order to simplify the construc- extremely low "C" circuit. Those ad- oscillator is used to drive another am- tion of the "driver," we used a 26 turn justments found optimum were 16 turns plifier not requiring a great amount of National coil form and a 250 mmf. tun- for 40 and 8 turns for 20. When oper- excitation the 45 -volt positive poten- ing condenser in the pla''e circuit. For ating on 10 meters with a 20 -meter tial need not be applied to the suppres- 80 -meter operation a coil would have crystal we had 2 turns in the circuit. sor, although when using a 20 -meter to be quite large in physical dimensions crystal and doubling to 10, bias on the in order to permit low "C," and it Use Plenty of By -pass Condensers suppressor is necessary in order to im- would thus make it more difficult to A very important item in a power prove the plate efficiency: And, by all obtain efficient operation on 40 and 20, oscillator of this type is by- passing; means, meters should be incorporated in especially 20 meters. plenty of by -pass condensers should be the screen (Continued on page 185) What Does It Cost to Become an Amateur? THERE are a large number of short- By Howard S. Pyle suitable for CW reception. This wave enthusiasts who, through lis- figure will also cover the total re- tening to amateur conversations, have ceiver cost for the enthusiast about to receiver regardless of whether it is an field with no equipment what- become imbued with the idea of joining oscillating type or not, will suffice. enter the the ranks of these transmitting hobby- soever. A more elaborate receiver may Should you however, elect to enter the be or purchased, at a later date. ists, and thereby enjoy the thrill of radio telegraph field you may figure on built two -way communication. in any price range that the user feels he an approximate outlay of $7.50 for afford, little two -tube Many books and pamphlets are avail- parts for a receiver or parts to con- can but the simple able which serve to show the "new -com- vert your present receiver if not now set will serve admirably while becom- er" just how to go about entering this ing acquainted with amateur opera- most fascinating hobby. Most books tion. Many such receivers have been of the fi- PHONE described from time to time in these all leave a vague impression S100 óo nancial outlay involved, leaving the TRANSMITTER pages and no attempt will be made here embryo radio amateur in a hopeless to discuss relative merits of circuits or muddle, not knowing whether he must SIMPLE -CW- equipment. or $100 to get on the air. It SET INCLUDES "FRILLS- We can drop the receiver problem spend $10 ( WITH RECEIVER) is in an effort to clear up this point right now with just a passing word on that the following paragraphs have been the antenna. A good single copper wire written. SIMPLE about sixty feet long and as high as you can conveniently hang it, will work Parts for "CW" Receiver Inexpensive OUTTIT about as well as anything for a re- We will assume that you are already .eiring antenna. This can be erected a short -wan.' listener, and accordingly complete for a total cost of about a have a receiver suitable for amateur dollar. When you have really become operation. In some cases however, such proficient as an amateur, more elab- a receiver will be of a non -oscillating $ 42 So orate types of antenna can be pur- type, ideal for radio telephone work, chased or built up as your fancy dic- but practically useless for the reception tates. of continuous wave (cw) radio telegraph signals unless a beat oscillator Cost of Low Power Phone is fitted to it. The cost of a beat oscil- If it is your desire to erect a trans- lator averages about the same as the mitting station at as little cost as possi- parts for a good two -tube A.C. short- ble you had better forget radio telephone wave receiver, so that you may choose for the time being. A good radio tele- between building a suitable receiver for phone-and neither the Federal Com- the purpose or adapting your present AVERAGE COST TO' GET ON THE AIR' munication Commission nor other ama- receiver to such work by the addition WrTH SIMPLE "LEGAL" TRANSMITTERS. teurs will tolerate other than a GOOD of a beat oscillator. If you are interested Graphs above show relative cost of be- phone -is a comparatively costly piece in entering the amateur radio tele- coming an amateur, with low -power trans- of equipment. Remember, in addition to phone field only however, your present mitters of course. a GOOD "CW" (Continued on page 179)

www.americanradiohistory.com 138 SHORT WAVE CRAFT for JULY, 1936

l'hotos above and at the left show the new "turnstile" antenna array in use at short -ave station, W8XH, Buffalo, N.Y. A 70 foot steel pole supports the antenna array; above -aerial being erected. Right -the 41.000 kc. transmitter used with the "turnstile" antenna. "Turnstile" Antenna Array at W8XH THE accompanying photos show a pole, 70 feet high, supports the array in the accompanying photograph oper- very interesting and unusual new of antenna rods, and the maximum ates at present on 41,000 kc., in con - style high -frequency antenna, which height of the antenna is 350 feet above nection with the turnstile antenna and has been named the turnstile aerial on the ground; it is mounted on the roof good broadcast reception on this high account of its resemblance to the well- of the Hotel Statler in Buffalo. This frequency is anticipated for a radius known turnstile. of twenty -five to thirty miles. There This antenna system novel antenna provides a strong ultra - are quite a number of listeners al- was designed by Dr. G. H. Brown of short wave radiation with horizontal ready who have been tuning in on the the RCA Victor Company. A steel polarization. The transmitter shown 41,000 k.c. wave of W8XH. Can 5 Meter Waves Extend Beyond the IN THE early days of 5 -meter working we were informed by the few experts available that radio waves Horizon? propagated with a frequency of 60,000; 000 cycles /sec. would obey quasi -optical D. R. Parsons explains the pecu- laws, resulting in communication be- liar behavior 5 tween points which were only visible of -meter waves from each other. The only way, there- and some of the extraordinary fore of increasing the receiving range things they would be by raising the transmitter or do under certain op- receiver well above the surface of the erating conditions. earth. It was supposed that no reflection or refraction occurred from the for reception purposes. How far these Heaviside or Appleton layers, the di- early assumptions were correct will now rect ray being the on y wave suitable be discussed at some length. If we have a listener operating a re- 80 ceiver at ground level, then the maxi- `'-,: -A- . mum theoretical distance (still on the N E W .: . ': ti MIM! assumption YORK . BERLIN of a purely visual range) CITY ú 60 over which he can receive signals from ..... z .,.in a given transmitter may be calculated mw 50 from an extremely simple formula. Al- j/%_ - 8_ ternatively, it may be ascertained from // \\\ J 40 AMEN Fig. 1, which shows the relation between / \\ 70RTABL úz G5CV the height of the transmitter above sea //// 30 level // o and the distance over which signals can be heard on the horizon. It NEW 20 YORK BERLIN G6SL should be emphasized that this curve i CITY FIG.3 10 definitely theoretical and is based on an elementary principle which most of us Fig. 2- Illustrating range (R1) of a trans- o learned many years ago. It assumes mitter T on the assumption of a straight O 1.000 2.000 3.000 4.000 that the intervening ground between the optical path. R2 shows the increase of HEIGHT OF TRANSMITTER IN FEET transmitter and the receiver is flat and range of waves following a "bent" path. that the power of the transmitter in Fig. 3- Illustrating the effect of reflection Fig. 1- Theoretical maximum range, on an from a single ionized layer. and of a com- optical basis, for various heights of the question is sufficient to energize the bination of refraction and reflection by transmitter. (Continued on page 187) two separate layers.

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 139 New Ultra S -W Tuner Has No Coils

In the realm of ultra short waves, down in the

region of I to 3 meter wavelengths, a brand -new de- parture in the tuning circuits is the adjustable concentric "resonant lines" system. When used instead of the familiar coils it provides a distinct gain in efficiency.

Photo above shows the new ultra short -wave tuning device which employs sliding brass tubes. in. stead of the familiar cop. per wire coils. Right- Closeup view of one of the concentric "resonant line" tuners. showing plunger and sliding antenna input terminal. Left- Assembled four - stage concentric line tuner; each circuit can be separately tuned. control. However, to compensate for any discrepancies in the circuits, each FOR the past year, concentric is provided with a metallic plunger line can be adjusted individually. Tun- cables and parallel transmission which permits tuning. In the finished ing is accomplished by shifting the lines have been used in transmitters. receiver, all five circuits are tuned ground position within the line. In However, it remained for Frances W. simultaneously which provides single ( Continued on page 172) Dunmore of the National Bureau of Standards, Radio Laboratory, to apply these successfully to a receiver. The usual tuning condensers and coils have been replaced by the concentric transmission line, which -in brief- consists of brass tubes approximately twenty inches long and about 1% inches in diameter with an inner tube 3/16 inches in diameter. The instrument shown in the photograph J employs five 954, RCA -Acorn tubes and five of these .concentric tuning devices. The receiver tunes from 100 to 300 megacycles or from 1 to 3 meters. The tuning units are mounted around a drum- shaped head on which is also mounted the Acorn tubes. This provides very short leads and maximum efficiency on these very high frequencies. Each of these so- called "lines" NViring diagram for four -stage concentric `resonant line" tuner.

Cathode -Ray Tube Tester New Television and Sound Antenna With the somewhat complicated look- rods, while the accompanying sound ing apparatus shown in the accompany- waves are broadcast on a different wave- ing photo, it is now possible to accurate- length, in this ly and quickly determine the most suit- case a short- able plate voltage to be applied to the er one than cathode ray tube under test. By means t h e image of this instrument, the complete tube wave, by the characteristics can be promptly ascer- lower array tained and recorded for future reference of antennas. and study. Among other factors which These two can now be measured and recorded antennae are (Continued on page 172) fed with current by two Newest apparatus set -up for testing the concentric luminosity, degree of vacuum, cathode appear- "transmis- beam intensity, etc., of cathode-ray tubes. ACCORDING to the reports ing in the English radio television sion lines," THE accompanying photo shows a magazines, television is about ready for which can be very interesting device for making their public. The accompanying photo seen passing cathode-ray tubes, shows the very interesting design of u p through measurements on of and and it was designed by the well - dual antenna, whereby the vision or the center known German radio experimenter, image waves are radiated in all direc- 'Co?,tin,eed Baron Manfred Von Ardenne of Berlin. tions from the upper array of antenna on page 172)

www.americanradiohistory.com 140 SHORT WAVE CRAFT for JULY, 1936 400 Megacycles Used by French "Hams" By C. W. Palmer

While the 3/4 meter band is open to American "Hams ", not Fig. 5 -400 mc. set in use as a "portable" very much use has been made of it so far, perhaps due to a on a car, with antenna arranged in a parabolic reflector. dearth of literature on the subject. The accompanying article describing a 400 mc. amateur radio transmitter and receiver AERIAL MF. will therefore undoubtedly prove of interest. AFT. RHEO.

0-2 MF. and circuits cover the 1.000 400 mc. (1a- OHMS meter) "rig" of amateur station HB9A0. 3S Cm 20,000 The receiver uses a dynatron circuit, n i2.srm MS 6V. OMMS TO shown in Fig. 1. The tube is metal .J a A. F. í200r. triode made by the Philips tube com- 500/ AMO. OHMS pany (Holland). The grid and plate £°°° are connected to a typical Lecher wire tuning system, with the plate and grid Fig. 1 -Above we have the diagram of a supplies applied through a twisted -wire 1 -tube 400 mc. receiver. 41cm. transmission line. The appearance of 2 WHILE amateur radio throughout the set is shown in Fig. 3. This photo the world has been shifting to higher shows the antenna, Lecher wires and and higher frequencies, as exemplified the set itself, installed in a neat metal -h by the activity on the 56 mc. (5 meter) cabinet. - 31 cm band and even on higher frequencies in As in the dynatron circuits used on this country, development in other coun- longer wave lengths, the grid of the tube E U f_ tries has not lagged. is driven at a high positive potential In fact, amateurs in France have from the "B" battery, while the plate been outdoing each other in attempts to is connected to a lower source of po- Fig. 7 -At left above is shown one form use the very high frequencies. tential and may even be at a negative of special antenna used; A is the free up- potential with respect to the filament. per end, and E is coupled to the transmit- Let us look at a few photos and cir- ter. 4 This variation in plate ob- Fig. at right shows dipole antenna cuits which appeared in recent issues of potential is used on one form of 400 mc. transmitter. Radio -Ref (Paris), the official publica- tained by connecting the plate supply tion of L'Union Internationale des line to the arm of a 500 -ohm potenti- up to about 35 km. (22 miles). Radio-Amateurs (The International ometer shunted across the filament bat- In the course of the experiments of Radio Amateurs' Union). These photos tery. these two hams, whose names are R. Because of the circuit arrangement Luthi (HB9A0) and A. Raviglione 4-1 in this set, M. Luthi, who made it, says: 0 "In these conditions, the action ap- (Continued on page 178) Od TOP VIEW OF proaches super- regeneration." This ac- SOCKET 95$ counts for the high efficiency claimed by O.aS-tMEG the author for his receiver on the fre- I quency of 400 mc., as well as on higher i 4001E SWITCH frequencies in the centimeter range. The single tube shown in the receiver CS 0.1.MF OSTER. circuit, Fig. 1, is the detector, which is followed by several stages of A.F. amplification to bring the sound level up to the desired point. 41 ) FIoKti The transmitter used by HB9A0 uses an American tube -the R.C.A. Acorn ttnp type 954. This transmitter, shown in Fig. 4, uses a horizontally polarized dipole aerial coupled to a Hartley oscil- Fig. 6- Portable beam antenna of para- lator. This transmitter is battery oper- bolic shape used by HB9RDL. The chord of the parabola 3 C6 ated, the battery circuits being isolated is meters. çç M 2S IpOV 160V A- A+ GMD. MF. from the high frequency circuits by Fig. 2-Another hookup used for the 400 chokes and filter condensers. mc. operations, showing both transmitter The circuit of the transmitter, or and receiver. rather the transceiver, for the "emet- teur" is actually a combined sending and receiving unit designed for mobile work in a car, shown in Fig. 2. The values of the parts are indicated on the circuit for those ambitious hams who might wish to duplicate the experiments of HB9A0 -or, in fact, try some new ones on their own hook. An interesting view of the rig used by HB9A0 when set up in a car, in conjunction with a parabolic reflector for Fig. 8- Curtain antenna for 400 mc. Each "beaming" the output is shown in Fig. section of the radiating and reflecting 5. units of the antenna network is tuned to 1 the carrier wave length. The outer sec- Fig. 3 -The 400 mc. receiver with Lecher HB9A0 has worked mainly with an- tions of the network are reflectors, while wire tuning system. other amateur, HB9RDL, at distances the inner (cubes) are the radiating units.

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 141 The All-Wave "AIRCRAFT 3" An Ideal Portable S -W Receiver By H. G. Cisin, M. E.

This extremely neat 3 -tube portable covers not only short -waves but the broadcast and long -ware radio beacon channels as well. It operates on batteries, with most any type of aerial, and can be set up at a moment's notice. It uses three type 30 tubes.

Photo at left shows the all - wave bands, five separate Hammarlund wave "Aircraft 3" portable plug -in coils are used. The long-wave receiver opened and ready coil is a special one available com- for tuning in stations. It mercially, or may be wound by the is a dandy headphone job, it but will also work a sen- set constructor. The data for this coil sitive magnetic speaker on is as follows: coil form 1% inches di- the stronger stations. Rear ameter; tickler 40 turns No. 38 en- panel view, showing the amel wire; secondary 2.45 turns No. 38 elastic hands used to hold enamel wire; space between secondary the tubes firmly in their and tickler 1/16 ". sockets, is shown in the Examination of the schematic dia- photo below. gram discloses several variations from the usual design, necessitated chiefly because of the introduction of the long - ware feature. It will be seen that the switch is closed only .00014 mf. tuning condenser is in series when the long -wave coil with a second .000325 mf. condenser, is used. When the THE All - which, in this case, is effective as an Wave Air- other coils are be- aid in tuning in "long- wave" stations. Three was ing used, the The way in which this works is as fol- craft switch is lows: The 15 mmf. antenna trimmer is designed especial- left open. a ly for use aboard shunted by second 5 mmf. fixed con- private planes, Aside from this denser when the long -wave switch is long -wave f e a - thrown. This permits the capacity of the motor -boats, ture, which adds antenna trimmer condenser to be in- canoes, or in usefulness (Continued on poge 189( camps, etc. How- to the ever, it is so com- R2 and ,IRr C2,50MMF plete, light L 75,0000HMS 500 sin ,/ MMF. compact that it 18 C7 is suitable for al- V2 01- 005 0l-MF. `MF MF. most any kind of L1 30) portable use. It takes up about as r 31 much room as Ou FUT a portable C 12 typewriter, but C3 weighs very much 140 / less, weigh - QtFMIMMIII111. i n g only 9 GND CO ECT ON TO R4 . R5) PAN 0.17- ¡ 40 CIO pounds, complete OHMS 0.1 -MF. with all equip- -COVER - MEG. ment, including batteries! Hence, it of this set for (2 /2)_ CA- A+ B+ can be used in a canoe just as conven- aircraft recep- B- 455 1,. 905. in an airplane. It is also well tion, this receiver iently as --BD % 12?" (DEPTH suited for automobile trips, for camp- is notable espe- 1 ing, for fishing trips, and for use on cially for i t s 3Y ) of other outdoor excursions. clean -cut, compact hundreds /ANT C6 500 Cil This up -to- the -minute receiver per- design. It uses a RI MME 500 IMEO. MMF. mits the air- minded traveler to sit at regenerative de- Cl, 15MMF. CT C8 CS,100MMF /MF. 113201 ( MF. ease on a long air journey and tune in tector and two s. radio beacons, weather reports and resistively s. 30) JI other information from the various air- coupled, audio - i ports passed over by the plane, com- frequency stages. o1/rP(R mercial code stations, standard broad- Low - drain 30 cast and also a full coverage of the type tubes are u short -wave stations from 17 to 200 used in all three meters. stages. To cover s t h e broadcast How Long Waves are Tuned In band and short - Radio beacons, conversations from airports and other similar signals are on the so-called "long" waves, Complete wiring received diagrams, both by means of a special long-wave coil schematic and pic- unit, in conjunction with a long -wave ture form, for the switch which throws a .00005 mf. con- CONNECTION "Aircraft 3" bat- , denser in parallel with the antenna tery receiver are TO PANEL 01 CA+,B- R7,400N145 1 trimmer condenser. The long -wave shown at the right. ONO. 45 901,)

www.americanradiohistory.com 142 SHORT WAVE CRAFT for JULY, 1936 1-Tube 1-Crystal 4- BANDS!

The new Beam -tube oscillator that made The new 6L6 Beam tube recently announced by R.C.A. represents one of the greatest history. advancements in radio tube design. Its possibilities at the present time are beyond compre- hension. In this article Mr. Shuart, our associate editor, describes the new tube and some it. Imagine a one -tube oscillator- tures of this design are very high -power of the tests run on an oscillator using doubler with 30 handling ability and high efficiency, to- watts input providing from six to seven watts of R.F. output at 20 meters, the fourth harmonic gether with high -power sensitivity, per- of an 80 -meter crystal! This represents an approximate plate efficiency of over 20 per cent, power out- less triode oscillator when operated at the fundamental mitting a large amount of which is not much than the ordinary put with no grid current flowing in the frequency of the crystal. input circuit. It is now possible to quadruple from 80 fo 20 meters, with sufficient power output to ex- According to the engineering data a amplifier. Subsequent articles will be published in forthcoming issues cite fairly "husky" available on this tube, the second har- describing further sets featuring this tube. monic distortion is intentionally high, in order to minimize a higher order of harmonics. The specifications of the UNDOUBTEDLY one of the great- tube are as follows: Heater voltage est advancements in vacuum tube A.C. or D.C., 6.3 volts, heater current design is represented in the new Beam. CONTROL .9 ampere; base is small octal SCREEN- the a Power Amplifier, R.C.A. type 6L6. This GRID 7 -pin. As a straight single tube, Class tube is of the all -metal variety and de- GRID A audio amplifier, with 375 volts on the signed primarily for audio purposes. plate and 250 volts on the screen, this Although designed for audio fre- BEAM - tube will deliver 11.5 watts. The max- quencies, this tube will undoubtedly CONTROL BEAM TYPE imum single plate current is 65 ma. make history as an R.F. oscillator and ELECTRODE PATHS OF and maximum signal screen current 6 frequency multiplier as well as R.F. ELECTRON ma. with an output load resistance of amplifier. The most distinctive fea- STREAM 4,000 ohms. ture of this tube is its electrode ar- Never before have we been able to ob- rangement. The electron stream is tain a tube with such plate efficiency as beamed by placing the screen and grid a Class A amplifier. Of course, for so that the cross -bars of the two are push -pull circuits, the output is cor- directly in line with each other. This respondingly increased. For Class A -B procedure causes a number of horizontal operation where no grid current flows streams of electrons. Then, on each during any part of the input cycle, it side of the tube we have a baffle which is possible to obtain 23 watts of audio! is connected to the cathode. The field This is with 400 volts on the plates and thus set up around these two baffles 300 volts on the screens, with a maxi- tends to focus the electron stream in mum signal plate current of 156 ma. two directions (sidewise). The high For Class A -B (Continued on page 177) electron density brought about by ar- ranging the electrodes in this manner, This drawing clearly indicates the elec- results in extremely low screen power, tronic action in the 6L6. Note that the electrons are beamed in two directions and suppressor action is automatically PLATE CATHODE layers, brought about by the space -charge ef- BEAM - and are also beamed in horizontal CONTROL due to the grid and screen wires being fects introduced between the screen and ELECTRODE in alignment horizontally. This beaming plate; no actual suppressor is necessary. results in the outstanding performance The tube is a Tetrode. The other fea described in the article.

CRYSTAL 6L6 ( BEAM TUBE 1 TO ANT. TUNING 300 MMF

OOY MF

0-100 MA 5w. 025 .D01- MA -- J MF B+ ,- B+ _ 150TO 350 TO 300V _6.3V.-. 500V.

The 6L6 Beam tube in four stages of production. Hookup of Oscillator which makes "quadrupling" possible.

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 143 2 -VOLT Short Wave Superheterodyne By Harry D. Hooton, W8KPX This Month's $20.00 Prize w....er

Front view of 2 -volt super -het receiver with loudspeaker A 4 -tube set, giving 5 -tube results and operating on 3 dry -cell "A" batteries. Works phones or speaker. IN developing this little two -volt short -wave superheterodyne the author's primary purpose was to provide a receiver which would insure good reception of short -wave broadcasts from every corner of the globe, but would include no "frills" or parts not absolutely essential to the proper operation of the set. This receiver had to be simple and inexpensive to construct and operate and above all designed in such a way that the oscillator and I.F. circuits could be brought into correct alignment with the minimum of adjustments. The result is the receiver here described. As Fig. 1 shows the circuit is quite conventional. A 106 is used as mixer- oscillator, a 30 as oscillator, a 34 as I.F. amplifier and a 19 as combined second detector and audio amplifier. Plug-in coils are used for complete coverage of all wavelengths between 15 and 200 meters. This range may be extended to include the standard 200 -550 meter broadcast band, if desired, by using the proper coils. Iron -Core I.F. Transformers Used It will be noticed that the 30 is not a separate oscillator in itself but is in parallel with the oscillator elements of the 106 tube. In this circuit both the 30 acid the oscillator section of the 106 are producing oscillations. This arrangement provides a much higher conversion gain than can be obtained with the 106 alone and assures powerful oscillation on the higher frequencies. Both of the 456 Kc. I.F. transformers are of the new iron -core type, which boosts the gain and increases the se- Close -up view of the 4 -tube super -het chassis, with two of the lectivity considerably. These (Continued on. page 174) plug -in coils,

- GANGED PHONES I. F. ANT 34I A IF Tt e 456 KC. % "FOR C9 DOUBLET (ANT o P C7

/ONO.

+ (CONNECT X, %,X,X TOGETHER) I 84-'67.5V. 6 +" 135V

C5 GANGED FT 1 PHONES I F DET 456 KC I 456 KC ANT 34 ) ( aw coaE) 19I 1 106 GaMIxER05C. ORAN CORE) (2 `. - -1

AFT. ,-(to 3:t FOR DOUBtEI (ANT

rONO

RS 3V.0 + -B +- 675V-. -8+ 135 V -. p-- 5w 2 - dV Wiring diagram of the 2 -volt short -wave "super -het" receiver. It uses iron -core I.E. transformers. Randspread is obtained, when desired, by using one of the new double -needle "handspread" dials, such as the Crowe type.

www.americanradiohistory.com 144 SHORT WAVE CRAFT for JULY, 1936 5 and 10 Meter

By George W. Shuart, W2AMN. With the constant increase in the number of stations operating on the ultra high frequency bands, modern transmitting equipment becomes a necessity. The transmitter described in this article, is crystal- controlled and may be operated on either fhe 5 or 10 -meter bands. On 5 meters an output of approximately IO watts is easily obtained. On IO meters the output is much higher, being nearly 20 watts. During tests on the air in the 5 -meter band, a transmitter of this type definitely proved worthwhile. The signal emitted was perfect in quality, even on the most selective of superheterodyne receivers. With the constant increase in the probability of DX transmission and reception on the 5 -meter band, crystal - trolled transmitters are, of course, the next step. DX can be accomplished more easily with a crystal -controlled transmitter and a selective and sensitive receiver. The older type modulated -oscillator, suffering from wobbulation, will not only stand less chance of covering great distances, but will spoil the chances of other transmitters because the former type emits such a broad wave.

Left W2AMN operating the- new crystal -controlled 5 -meter transmitter. The crystal microphone, together with the "high fidelity" modulator. permitted "broadcast" quality to he obtained.

Below-Bottom view of the transmitter, together with closeup, showing how the instruments are I placed on the front panel.

V- the improved apparatus. (Such as the recently reported 5 meter QSO between FOR a number of years, ultra high Troy amateurs and England.) frequency transmitters have been of the more simple variety. These trans- Starts With 20 Meter Crystal mitters have served their purpose ex- The transmitter described in this ar- cellently, and permitted the healthy ticle and shown in the photo is of the growth and development of the ultra- crystal -controlled variety, starting out high frequency bands. However, the with a 20 -meter Bliley crystal. In the expansion of the ultra high frequency oscillator circuit we have a 6C6, which bands has been tremendous, and pres- is used as a tritet oscillator- frequency ent -day conditions demand that the multiplier. Here we double to 10 meters transmitters be of the more modern in the oscillator stage. And for oper- variety. There are many who com- ation on 10 meters we have an 802 buf- ment on the uselessness or the lack of necessity for a crystal -controlled ultra- high frequency transmitter. Many claim that they are not necessary because they do not notice frequency modulation on the present receivers. This is true with a good many of the present receivers, simply because the receivers are so broad that they will tolerate a tremendous amount of frequency modulation! However, the writer has found that even a really selective super -regenerator will show up poor modulation and certainly, some day, we are going to have receivers that are more selective than the so- called "resistance - coupled" super -heterodyne or the super - regenerator. But the fact is that we could provide space for hundreds of times the present number of stations now operating, and still have no Q.R.M. (interference) should the transmitter be crystal- controlled and the receiver a really selective one. Some think that this condition will never come about, but it only remains for some fortunate "Ham" to make a qualified long -distance contact; then watch the rush for

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 145 Crystal Transmitter .. fer and an 802 final amplifier. With 500 volts on the plate of the amplifier, it is possible to obtain nearly 20 watts output on 10 meters. For operation on 5 meters, the first 802 doubles from 10 to 5, and the final 802 is again used as a straight amplifier having an output in the neighborhood of 12 watts. In this transmitter we endeavor to utilize conventional circuits and practice, to see just what efficiency might be obtained without the use of special ultra- high- frequency tubes and special circuits. Of course, the 20 -meter crystal greatly simplifies the transmitter and reduces the number of stages over those necessary for use with another crystal of lower frequency. Screen and Suppressor Connected Together While each of the three tubes in this transmitter is a pentode, we connect the screen and suppressor together making them tetrodes. Careful measurements have proved that this connection proved more efficient than the pentode connection. In each of the four tuned circuits, it will be noticed that the rotors of the condensers are at ground potential. In the two amplifier stages, split stator condensers were used in order to main- This rear view clearly shows the constructional details. tain this feature and thus eliminate the necessity of insulating the rotors from when they are all on the same chassis were not used. The plate tank coils of the chassis. Plenty of by -pass condens- and there are no shield compartments, the oscillator and two amplifier stages ers are used and they are absolutely deserves careful attention as to by- are of the "plug -in" variety as can be necessary wherever indicated in the passing. In the.transmitter as de- seen in the photo. Bandana type plugs diagram. scribed, there was no indication of harm- are soldered to the coils, thus facilitating Operating a series of amplifier stages ful reaction between the stages, although band changing. We have provided at relatively high frequencies, especially separate compartments for each stage jacks for (Continued on page 184)

6C6 100MMF. 1100MMF 100MMF) 50-50MMF. 802 5050MMF. 20 METER 802 ` R.F.C. / i R.FC. CRYSTAL I / L5 2.5 / °Oj f° G F. -.gr...., Zr o + G4 ` g 1+ OI r O L3 I_?` L4 es 1 R.FC. Jj 50 [ ,SwiELD MMF 2.5 M66 SI1'WrtW =Iw 4 a N .001- K K wlw MF .001= 1x x 1 i K x "l MF. 001-MF T001- ,001- T.001. MF. 140 MF-'T MF. .001 I1 MF. ,10 ~MMF. I .001-MF. I C .001- 50,000 MF. /.001- FOR CW OHMS 500,t000 T MF. KEY WERE

(6CsÁ0Ó7TOM"v°IEwj ~ .11 D (802 SOCKETS SHOWN, C- TOP - 90V. MODULATOR VIEWS) V' J3 l J2 ONMS 50,000 C TRANS. OHMS % / 35 WATTS J4 }0 6.3V. . v;° ®/SW.I 20Nr. ®^ ® ` % 150 M A . ) SW 2 S , W] 1 i 1 i // l' ¡pp(Y SOOV 1 sv./ 1 cwo1.E-, 83V. $MF.` OHMS SW 8(EACH) 44 T T 25,000 SwTCH \, 465V, I OMMS 1=-.%r' Ó A + + l I 8 MF ` WATTS50 C_ (EACH) pAVS T T 22 5 TO '-fHO: %3;,,. 45V.

110V,A.C. I I

Wiring diagram of the crystal -controlled 5 and 10 -meter transmitter, which starts out with a 20 -meter crystal. Three screen grid stages are used and modulation is applied to the plate and screen of the "final" amplifier.

www.americanradiohistory.com for JULY, 1936 1.16 SHORT WAVE CRAFT SHORT WAVES and Our Readers Forum. LONG RAVES

PERTH AMBOY, N.J., HAS A -1 STATION CRACK MAINE PIIONE STATION. STEPHEN CASEY, W2IIR, 1l This Months Prize Winner HERBERT W I L M A N, W1IUV of Editor, SHORT WAVE CRAFT Skowhegan, Maine, sends us a photo- I have been a subscriber and reader of graph of his very neat phone station, not Short Ware Craft for the past five years forgetting that Mr. Wilman appears in and I should take this opportunity of the photograph with a young lady who, we thanking you for the "FB" informations presume, is his "Missus" or XYL. and diagrams published in every issue. Noting your request for "Ham Station" Apparently, this is one time when photos I am sending a picture of my Xmit- "Ham" radio did not disrupt the tranquil- ter. ity of the home -at least we believe so, Using a 47 crystal- controlled oscillator, noting that the XYL was induced to pose 46 first buffer, two 210's in push -pull as sec- heavy-deity radio. Maybe she takes her turn ond buffers and a pair of 211 with the about 500 watts who can tell? tubes in the "final," with at the mike, input. The transmitter consists of a 47 crystal RCA D.B. microphone, 56 single speech, oscillator, 46 first buffer, 210 second buffer Xformer coupled to a pair of 50's in push - of 2A3 drivers a 203A final amplifier, which in turn pull; then coupled to a pair and in class "B." by two 210's in class B, with and using n pair of 242A's is modulated a antenna, with Collins im- and drivers Using Zepp the necessary speech amplifiers pedance- matching system. to work in conjunction with a double -but- The receiver is a seven tube superhet and ton microphone. The receiving equipment having a two -stage pre -selector in a sep- consists of a Stewart -Warner, 9 -tube all - arate cabinet. wave affair, and a National SW -3. So far I worked on 160 meters only, having many pleasant contacts with VE Mr. Wilman credits W1KL for helping 1, 2, 3, Wl, 2, 3, 4, 5, 8, and 9th Districts. him in constructing the transmitter. W1- Expect to be on 20 meters shortly and all United States dis- hope to have some nice QSO's with foreign IUl' has contacted four different tricts, which is quite remarkable, having stations. I am able to speak worked Los Angeles and California and languages. I am enclosing a diagram for a as DX contacts. 350 Also Fort Worth, Texas, power Xformer supplying the class "B" and cards were received in a period of 10 the final stage with very good voltage regu- months. lation. Crack "llam" station owned and operated amateurs use only one X- F'. B. Herbert and the XYL -we hope to Many fellow by Stephen Casey, W21I11. Perth Amboy, hear from ¡pm ago in. (Continued on page 177) New Jersey

1900 hours on the FB QSO with a W. same band. The We are only allowed to use 50 watts in- W6's are worked put to the final amplifier over here, and as on 7 mc. in the af- far as I am concerned the restriction is an ternoons; at 1500 excellent one. There is not much qrm from hours GMT and the the local stations and we all get a fair eastern side on the share of the band. There are five stations same band at 0600 all within a circle of about a mile in diam- GMT, if my 40 eter, all using 50 watts, and we all use watts is able to (Continued on pape 177) break through the QRM over there at that time. To show you how easy it is One Year's Subscription to to communicate SHORT WAVE CRAFT with North Ameri- FREE ca, ZE1JB worked for the "Best" Station Photo 28 W's in one night Closing date for each contest -75 days preceding and lost no sleep. date of issue: June 15 for Sept. issue. ele. The storms are editors will act as judges and their opinions will Tropical be final. In the event of a tie a subscription will our QRM over here be given to each contestant so tying. and bad lightning hascurtailed many a Photo above shows excellent transmitting and receiving station, WIIEV, located at Skowhegan, Maine

GOOD NEWS FROM RHODESIA, S OUTH AFRICA Editor, SHORT WAVE CRAFT From Bulawayo, Herewith is a photograph of my trans- North America, is mitter which is operated under the call the easiest country signal of ZE1JN. The transmitter used to to communicate slide into a dustproof cover, but it was re- with both on 7 mc. moved so often for improvements and alter- and 14 mc.; all the ations that the cover was discarded. divisions have been The bottom stage is the crystal- controlled worked except W7, oscillator, a 2A5 valve is used as oscillator which division has with 350 volts on its plate. The second not even been stage is the frequency- doubler stage; here heard. The VE's a 2A5 valve is used, connected as a pen- are also very rare, tode. The output of the frequency dou- but have been bler is link- coupled to two 46's in push -pull, worked from here. with 550 volts on their plates; the input to At 1,200 hours the final is 40 watts. Several aerials are GMT, the eastern band the trans- divisions be used, depending upon which can has a dandy crystal is worked on 14 mc.; R. Jubb, ZE1JN, South Rhodesia, South Africa, mitter is working and also which station. used. similarly at about

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 147 WORLD -WIDE SHORT -WAVE

REVIEW -Edited By C. W. PALMER

A French All -Wave Tuner All -Wave Frequency Meter AN IDEA of the progress in the design The Editors have endeavored to review IN designing and operating high -fre- and manufacture of all -wave the more important foreign magazines receiver covering short-wave developments. for quency apparatus such as transmitters, components in France can be obtained from the benefit of the thousands of readers of etc., it is important to know the exact fre- the accompanying picture from Machine this magazine who do not have the op- Parlantes Et Radio (Paris). portunity of seeing these magazines first- The hexagonal container combines a hand. The circuits shown are for the shielded compartment for the coils for each most part self -explanatory to the radio band and switch student. and wherever possible the con- a for changing from one stants or values of various condensers. coils. etc., are given. Please do not write to us asking for further data. picture - diagrams or lists of parts for these foreign circuits. as we do not have any further specific information other than that given. If the reader will remember that wherever a tuned circuit is shown. for instance, he may use any short -wave coil and the appropriate corresponding tuning condenser, data for which are given dozens of times in each issue of this magazine, he will have no difficulty in reconstructing these foreign circuits to try them out. The container shown incorporates a shielded compartment for the various coils, and also a switch for changing from A New German S.W. Coil one band to another. A NEW line of S.W. coils design- band to another. This coil assembly com- ed to have an unus- bines all the coils for a superheterodyne ually low R.F. resist- set, covering the wavelengths from 10 to ance (high Q) was 100 meters and the "broadcast" band. shown in the latest A recent type of German frequency meter This unit is a fine example of how com- issue of Radio Bild- having a range of 150 kc. to 60 mc. pact and complete such a coil assembly can funk Fernsehen Für be made. Alle (Stutgart). quency at which a circuit is resonating to A s shown, t h e keep on a given waveband -or in the case coils are wound with of frequency doublers, and tank circuits, An Ultra High- Frequency Transceiver flat silver ribbon on the efficiency of the transmitter depends on TRANSCEIVERS, which have found deeply ribbed forms. the care with which the various circuits are much popularity among hams for mobile Thus the high fre- tuned. work have now graduated into the ultra- quency resistance of A frequency meter which is very useful high- frequency class. the conductor is ex- for such purposes was shown in a recent In a recent issue of Radio -Amateur tremely low (skin issue of Der Qualitätsmarkt (Berlin). It (Vienna) several interesting circuits of effect, etc.) and a very small amount of contains coils covering the frequency band this type were described. One of these is insulation is inserted in the coil's field. between 150 kc. and 60 mc. reproduced here for anyone who may wish A meter indicates the output and a neon to try it. indicator gives a visual check on the signal The tubes used are of American origin, intensity. The various coils, covering the being two double triodes of the 19 type wide frequency range mentioned above are with a triode, which may be a type 30. W4i- connected by means of a band switch. The For transmitting, one 19 acts as the os- t1 dial is a full- vision airplane type indicator, cillator while the 30 and the second 19 v..- with all scales plainly marked. act as modulator and speech amplifier, re- An instrument of this type is as useful spectively. When receiving, the 19 -which .1 to the transmitter as an all -wave oscillator was or frequency generator is to receiver. the oscillator- becomes the detector, _ - 100 0.1 the MMF. followed by the 30 as first A.F. amplifier MF MEG. and the second 19 acts as a push -pull sec- El+ ond A.F. stage. `e / 1 A Simple Crystal -Controlled Portable A system of switches, operated simul- 20.000 50.000 f Xmitter OHMS 0.1-MF. 0.1- taneously by a single toggle change the MF. O IN THE T & R Bulletin (London), which circuits from the transmit to the receive is the official magazine of the Radio position. Dry batteries supply both the _ Society of Great Britain and the British "A" and "B" voltage. - 100 MMF. Empire Radio Union, a simple yet effective The inductances for the grid and plate scheme for operating a transmitter on circuits depend J on the frequency at which A .Ol- either 7 or 14 mes. was presented. the unit is to be operated; for 5 -meter MF. The circuit of the fundamental unit is work, they consist of one turn wound to a shown with values to permit the reader to diameter of about 3 ins. 8-i (Continued on page 185)

A novel "frequency changer" circuit for R.F. C.1. 38 05.0 _ 6+ use with superhets. WIRE ON y2- REC2 Frequency Changer in S.W. Superhet -s DOWEL IN A recent discussion on the design of R1, 30,000 al OHMS 30,000 short -wave superheterodyne receivers OHMS which appeared in World -Radio (London) some interesting circuits and comments were presented. ..(loruRNS) The circuit preferred most by the author 47 for producing the I.F. beats is the one shown here. It consists of a pentode frequency- changer or first detector, which is connected in conventional fashion between the aerial (or previous R.F. tuner) coil and the first I.F. coupler. The oscillator is an electron- coupled or cathode feed -back unit which is chosen for stability. This oscillator is fed into the suppressor grid circuit of the first detector, since this supplies the most stable opera- Diagram of an interesting ultra -high fre- tion and has the least effect on the operat- A new English circuit of interest to quency Transceiver. ing conditions of the detector tube. 'lfams "-a crystal- controlled transmitter.

www.americanradiohistory.com 148 SHORT WAVE CRAFT for JULY, 1936

$5.00 Prize 0.25-MP. 400V CONDEI.iSERS ANOTHER CODE PRAC- TICE KINK $5.00 FOR BEST By Joining the earphones a key and two 250 mod. condensers In series and connect them across the A.C. line, we have a simple -WAVE KINK 1111M rode oscillator. however, extreme care SHORT hold lie exercise) in order to avoid corn- ing in minuet with the A.I. line. -Donald The Editor will award a five dollar prize each month item. for the best short -wave kink submitted by our read- 74007,1 ers. All other kinks accepted and published will be awarded eight months' subscription to SHORT ONE LAYER ` WAVE CRAFT. Look over these "kinks" and they NEIA OR 16 ENAM what the editors are look- COPPER WIRE will give you some idea of N POWE0. TRANS. 110V IN Pula SUPPLY ing for. Send a typewritten or ink description, with AC .ketch, of your favorite short -wave kink to the "Kink" Editor, SHORT WAVE CRAFT. COIL HANDLE I wound coils on tube bases and In order to provide a handle for them, selected a glass knob. long 1 lamp. which serves as a poten- the -watt HOME -MADE GALVANO- Bo the ae.Ofsew lcourse there is a knob tue b tial dropping resistor. This simple may lie some slight lessee sine to the gene which can be operated any METER arrangement running through the mil. I le -e r, prar- Mare where line Althollgh this "kink" la not mIginal by Ileal tests showed no appreciable r difference o nlbeg0renewed.-Ed. arty means. though them are undoubtedly a with or without the screw.-John llaug ila. Togesel. great radio are not familiarf with tii, Ideaaml there- tore. I think it should be published in the "kink" department. 3:1 01 It consists merely of winding wire around a small compass. It will serve to Mark eno- tinuity. It is only necessary to use a small CHASSIS BENDER batten- for operating the 'miter. When current passes through the coin. the needle will l'r a number of years I have i.een ..- show a defiers to depending upon the .Inuring radio remising sets and hate al- amount of that current.- -.lark fhanerller. nays mocrietteed considerable difficulty in forming the chassis or bases. The drawing (6) clearly illustrates hoe I simplified the chassis problem. No dimensions are given. as they will defend upon the dimensions of Ilse chassis to be Conned with an sr- rangetent of this sort. It is a simple plat- r 25W. KEY ter to make sharp lands. The result is a neat and actuate chassis, -Cecil Denanero. LAMP 1P PHONES o ,1101r.`, A.C.-D.C.

HANDY TESTER KINK CODE PRACTICE TRICK Having lllfieulty in finding a place for It Is not necessary to go to all the trouble the "test leads' on my hone -made tester, of buildieg a special rode oseiilator if one I struck upon the following ilea: A spring- Is eetislied with It lee frequency tale. reel cigarette -lighter Wan remodeled and Merely wrap one wire armed the outside eonnecleI. as shown In the drawing. When of the drop cord, attaching It to earphones. the test leads are no longer in use. sim- and then between the other metrication of ply release them and they will wind up' the earphones on the groom!. insert the key. the spring -reel. L. The light does rot nerd to be lit during automatically in -W. but HANDLE I rev in. operation. will strengthen the signal.- Fern Il 'l'user. WINO NUT BOLTS HINGE ARE COUNTERSUNK, SPRING REEL WASHERS ARE NECESSARY CIGARETTE LIGHTER SOLDERING IRON UNDER WING NUTS it le a simple natter to construct a efficient soldering iron holder from a discarded The drawing clearly illus- WIND ABOUT 20 tie-eum TO TURNS trates just hew the holler is formed. 'l'I..- 30 OF very arrangement and ea., /FINE wtRE AROUND is a simple ,/ construct and will provide a convenient DROP CORD for the soldering iron, which is the I. SPEAKER HINT MA. permanent tool used by a short -wave "Fan." PHONES I have been confronted with the problems This holder may be mounted in some out of replacing the dynamic speaker with one of the way place underneath a bench, whirl. that would not have quite We same field liens that the iron will always be hand. PIPE nsistance. This was easily menmne by p not In the way when not being Used.- inserting a resistor in series with the field. John Berner. The lesisinr, of course. should be equal to the difference between the two This fields. MULTI - only works when the field resistance of the TEST DOINT new speaker Is less than the old one. PRODS clearly the idea. r SWITCH The diagram illustrates This procedure will result In applying the ERIC seine rnitartlet to the toles as wins the orig- LIGHT CND. inal speaker. -J. E. Riley. COIL WINDING SUGGESTION PRESERVING QSI. CARDS Many times builders of short-wave re- Ifere is a "kink" w'hieh keeps my QNI, ceivers who wInd their on roils have been earls clean and fire from dust. This will unable to make the set oscillate around also present the edges from befouling frayed frequencies between 14 and 20 reegaryrles. tMO the lettering Illegible. thus improving The waiter overcame this trouble by thread- he auncer:1nm of your listening den. ing a portion of the tickler winding Into Tim 11WI, card is placed fare ds.'meant the B !neatIvo side of the grid coll. The on a sheet of ellol.hare, leaving a ae Inch drawing will convey the idea more clearly, border on each of the four sides. You then with this arrangrme nt. there was abso- lap the borders or er the reserve side of the lutely no trouble in obtaining regeneration e:n1 and paste them don. Tho drawing or oscillation at the very high frequencies. clearly illusi retea the stages explained . Cntdberg. -Carl Bmetka. - ata.se.- \nu.ld

CELLOPHANE COVERED CM HOME -MADE LINE CARD FILTER COMPLETED I Bel submitting the following "kink" FOLD for i-utr very Interesting page. Living In CELLOPHANE the fl'igldniuoe1 where line -noise interfer- AS SHOWN, ence is eseeptionally high. I tiled the fol- AND ALL- ELECTRIC CODE lowing in order to eliminate the tnnlble. PASTE I was much surprise) to find that It OSCILLATOR overeat. the majority of the noise Auld Building the "code praellre" arIllator made reception more satisfactory. As the The one least ink shows, two y mf. 4u0 -volt con- has always been quite a problem. the illustrated in the diagram operates front densers are ennnectet In serles across line and the center -lap grounded. Over each troter A.C. or D.C.. 110 volts. It is of a No. and of course the of these tubular condensers layer of he self -rectifying ove wire is wound; these QSL be by the \.1'. Of II or 16 enamelled 1 INCH BOR- rote 51111 modulated chokes. Any one trying course. approximately 110-volts will he ap- windings form the CARO, FACE DER ALL AROUND und the Ola this will undoubtedly experience fine results DOWN plied to the plate of the tube C. Gould. ment of the 201A. receives its paver through as I have.-Clair

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 149 SHORT WAVE .

TWENTY -EIGHTH "TROPHY CUP" .SCOUTS Presented to SHORT WAVE SCOUT Honorable Mention Awards HAROLD E. BISSELL, JR. J. Wendell Partner, 3618 So. Faw- Toms Road, Stamford, Conn. cett Ave., Tacoma, Wash. 46 For his contribution toward the Carlos Lizarry, Johnson St., advancement of the art of Radio Brooklyn, N. Y. by

if the "veri" card is received with a wrong date on it or possibly no date, do not fill in the date yourself, but return it to the station and ask for an- Magazine other one and request that the exact date be filled in by them on the card. (It is also a good idea to send another 28th TROPHY WINNER Postal Reply Coupon.) Quite a few cards have been altered or dated by the 65 Stations -48 Foreign contestant in the past, and if these are THIS month we salute Harold E. detected by the judges, they will, of Bissell, Jr., of Toms Road, Stamford, courser be rejected. The list of sta- Conn., for his fine list of short-wave tions in Mr. Bissell's Trophy winning stations heard and verified. This ex- "log" appear below: cellent "log" of short -wave stations was (Continued on page 182) received over a 30 -day period on a 16- tube Midwest all -wave receiver. Three different type doublet aerials were used, ON this page is illustrated the hand- depending upon the frequency of the some trophy which was designed by station which was being received. The one of New York's leading silversmiths. antenna switch -over was accomplished It is made of metal throughout, except the base, which is made of handsome by means of a gang switch mounted on black Bakelite. The metal itself is the side of the receiver cabinet. Mr. quadruple silver -plated, in the usual Bissell mentions that it is very inter- manner of all trophies today. improvement It is most imposing piece of work, esting to note the great and stands from tip to base 22'4 ". The in signal strength, when the proper diameter of the base is 7%" . The length doublet is used. diameter of the globe is óys ". The work throughout is first- class, and no Mr. Bissell further remarks that in money has been spared in its execu- order to obtain the long list of verification. It will enhance any home. and tions here reported, he wrote 105 re- will be admired by everyone who sees it. The trophy will be awarded every ports to the various stations. He also month. and the winner will be an- points out that quite a number of the nounced in the following issue of verification cards were received from SHORT WAVE CRAFT. The winner' name will be hand engraved on the the stations with wrong dates on them, trophy. and also that some of the cards bore no The purpose of this contest is to ad- date at all. vance the art of radio by "logging" as many short -wave phone stations, ma- We would like to stress the point once teurs excluded. in a period not exceed- more to our many short -wave friends ing 30 days. as possible by any one con- and aspiring "trophy winners," that testant. The trophy will be awarded to that SHORT WAVE SCOUT who has no matter how sure you are of the pro- logged the greatest number of short- gram and date on which it was heard, wve stations during any 30 -day period.

Trophy Contest Entry Rules THE rules for entries in the SHORT WAVE month. by which time all entries must be in stations on your list for entry in the trophy SCOUT Trophy Contest have been amended the editors' hands in New York City. Entries contest! and 50 per cent of your list of stations sub- received after this date will be held over for mitted must be "foreign." The trophy will be the next month's contest. The next contest SHORT WAVE SCOUTS are allowed the use of any receiving set. from a one -tuber awarded to the SHORT WAVE SCOUT who has will close in New York City June 26th ; any up to one logged the greatest number of short -wave sta- entries received after that date will be held over of sixteen tubes or upwards, if they so desire. tions during any 30 day period; (he must have till the next month. When sending in entries, note the following at least 60 per cent "foreign" stations). This few simple instructions: Type your list. or write period need not be for the immediate month The winner each month will be the person in ink, pencilled matter is not allowed. Send preceding the closing date. The complete list of sending in the greatest number of verifications. verification cards, letters and the list all in one rules appeared in the September issue of this Unverified stations should not be sent in, as they package. either by mail or by express prepaid; magazine. will not count in the selection of the winner. At do not split up the package. Verification cards least 50 percent of will a the verifications sent in by and letters be returned. at the end of the In the event of tie between two or more each listener must be for stations located out- contest. to their owners; the expense to be borne contestants, each logging the same number of side of the country in which he resides! In by SHORT WAVE CRAFT magazine. stations (each accompanied by the required other words. if the contestant lives in the minimum of 60 per cent "foreigns ") the judges United will award a similar trophy to each contestant States at least 60 percent of his "verses" must In order to have uniformity of the entries, of be from stations outside of the United States. when writing or typing your list, observe the so tying. Each list stations heard and sub- Letters or cards which do not specifically verify following routine: USE A SINGLE LINE FOR mitted in the contest must be sworn to before reception. such as those sent by the Daventry EACH STATION; type or write the entries IN a Notary Public and testify to the fact that the stations and, also by commercial telephone sta- THE FOLLOWING ORDER: Station call let- list of stations heard were "logged" over a given tions, will not be accepted verifications. 30 day reception was verified as Only ters: frequency station transmits at; schedule period, that and letters or cards which "specifically" verify re- of transmission, if known (all time should be that the contestant personally listened to the ception of "given station." on s wave reduced station announcements as given in the list. given to Eastern Standard which is Ave hours length and on a given day. will be accepted! In behind Greenwich Meridian Time) ; name of sta- Only commercial "phone" stations should be other words it is useless to send in cards from tion, city, country; identification signal if any. entered in your list, no "amateur transmitters" commercial telephone stations or the Daventry Sian your name at the bottom of the list and or "commercial code" stations. This contest stations, which state that specific verifications furthermore state the type of set used by you to will close every month on the 25th day of the will not be given. Therefore do not put such receive these stations. State total No. stations.

www.americanradiohistory.com 150 SHORT WAVE CRAFT for JULY, 1936

The short -wave apparatus here shown has been carefully selected for description by the editors after a rigid investiga- WHAT'S NEW tion of its merits In Short-Wave Apparatus 5 Meter Xmitter and Receiver Portable

A five meter portable mobile duplex transmitter and receiver By Irving Rosenburg, W2CQI

Front View of 5 Meter Transmitter and Receiver ACTIVITY on the five meter band for the past year has increased by leaps and bounds, as one can readily determine by listening for a few nights on this frequency. Inasmuch as it is legal to operate portable mobile transmitters by licensed operators on this band, much more activity is noticed during the warm summer months. This duplex portable station about to be described can be operated in an automobile, yacht, motor -boat or airplane using a 6 volt Genemotor capable of supplying 300 volts at 100 mils it can be operated also as a permanent fixed station in the shack, connected to an a.c. power supply capable of delivering 300 volts at 150 mils. The power output of this transmitter is rated at ten watts.

TO ANT 50000vCNMS TOAST. 6a6 0.5 MEG Top View -Looking Down Into the 5 Meter Set Mc TRANS,' The "Eagle Duplex Minuteman transmitter and receiver" con- it: sists of (transmitter) 1 6A6 class "A" parallel connected speech - amplifier and driver, 1 -6E6 unity coupled push -pull oscillator. The receiver used in this portable station is the one already described in the April issue of Short Wave Craft. Both units 104MS are contained in a black crackled cabinet 17x834 x8 inches with panel to match. The panel contains the plate milliammeter, two 5MF GANGED SwITCN nickel -finished dials -one for the oscillator and one for the L_ receiver. Plug -in arrangements are provided for current read- POWER ing on the modulator and oscillator. Also incorporated on the S. _ 020 panel are two "stand -by" switches, one for the transmitter and ÓAT T the other for the receiver. Another jack is provided for the T microphone as well as a gain- control for same. A red bullseye J3 lights up when the power is on. All controls are symmetrically present a very pleasing appearance. JACK -- aranged and STANO-gv SWITCH The 6E6 dual triode was chosen for the oscillator, due to its inherent stable characteristics and its higher efficiency on the Hook -up of 5 Meter Transmitter (No. 546) ultra high frequencies. The 6A6 class (Continued on page 166) NEW WORLD TIME CLOCK THE handsome appearing clock shown the same day. Another example -if Mr. at 9 p.m., a glance at the clock dial proves in the accompanying illustration is Smith at his home in New York, desires that it would be useless for him to tune available with an electric movement, for to hear "foreign" music on his radio set in on Rome, because it would then be operation on 60 cycle 110 V. A.C. circuits, 3 a.m. the following day, and that he would or with an 8 -day spring movement. more likely be able to get Honolulu, Hawaii, As the name implies, the purpose of this where it is 3 p.m. the same day. clock is to give the time in various parts With this world time clock on his desk, of the world in relation to the time at the Mr. Jones, a New York City business man, place where the clock is situated. For will note that to get Mr. Smith on the example -if the clock is set for New York telephone in Rio de Janeiro at 4:30 p.m., City time, by merely looking at the face Rio de Janeiro time, he must call him at thereof, a person can tell the time in any 2:30 p.m. New York time. shows Our Information Bureau will gladly sup- other part of the world. If the clock names and addresses of that it is 11 p.m. in New York, it will also ply manufacturers' indicate that it is 4:00 a.m. in Ethiopia. any items mentioned in Short Wave Craft. This result is obtained without mental cal- Please enclose stamped return envelope. culation of any kind merely by reading the face in the same manner as in reading the time from an ordinary lock. This World Time Clock is constructed to With the use of this clock, it is possible show at a glance the relative time in any to quickly tune -in a foreign broadcasting part of the world. This fine looking time- station on any particular program at any piece is available in electrical or mechani- given time. For example, if the English cal movements, and the mahogany case Premier is scheduled to speak from a Lon- measures 83. ¡" across the base and 83g' don station at 8 p.m., London time, by re- high. Very useful for students, business ference to this clock, one can quickly see people, and by all means S -W Fans and that his radio must be tuned in at 3 p.m. Hams. (No. 547) Names and addresses of manut of apparatus described on this sad fallowing pages furnished upon receipt of 3 -cent stamp: mention No. of article.

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 151 The RX -14 S -W Receiver

f h e For "Fan" or "Ham" a p pear. ante of the RX- By Guy Stokely, E.E. 14 short wave re- suit-Ce r. pentode output tube capable of delivering as high as 3 watts able for of audio power to the built -in dynamic loudspeaker. The 'F an" or 'Ham." use of 3 stages in this amplifier insures ample volume on may be all stations. No traces of audio feedback or noted instability are from the present, due to a careful choice of circuit constants. aceom- A type 5Y3 tube is used as the rectifier, due to its low pans ino photo. It internal voltage drop under full load. Full -wave rectifi- is a very smooth cation and an exceptionally good filter system results in a work ins totally hum -free power supply. All traces of tunable hum job. are eliminated by the proper use of by -pass condensers at points where such effects generally originate. THE Model RX-14 short -wave receiver incorporates Excellent shielding, cadmium -plated for high electrical many of the features which are found only in the finest conductivity, and a proper arrange- (Continued on page 171) of tuned radio -frequency receivers. Designed for the short wave "fan" or the transmitting amateur who requires ex- SHIELD is 540 LSP [LO P treme selectivity and sensitivity, it should prove to be a LoLf MF. l'ar thoroughly reliable and dependable receiver. 1.2 I % A glance at the circuit diagram indicates the use of six '°.4- 01-W seam / /.OtHi .i of the high -gain type of tubes, i.e., 6D6- 6D6- 76 -76 -42 -5Y3 OS. functioning as tuned R.F. amplifier, tuned electron coupled 1 G t 42) screen -grid regenerative detector, powerful 3 stage resistance- coupled audio -frequency amplifier, full -wave high - voltage rectifier and a complete "built -in" power supply. Either a noise or single wire type of al -eliminating doublet 2E.000 antenna may be employed, with equally good results. Vol- p+MS 2.000 ume is controlled by means of the potentiometer Rl, which OHMS 1 controls the negative bias GÉ 0i 0t grid on the R.F. tube. The out- G MEG Ol put of the R.F. stage is electro- magnetically coupled into OP' PT 01-M 300 OHMS the grid of the detector, which uses an electron -coupled 5V3 eeo0 eH regenerative circuit. Regeneration is controlled by means ONO r. / .p tbl of the potentiometer R5, which has a specially tapered re- GANGED 0i C. =IS PPP sistance curve and results in an exceptionally smooth oscil- tSMr lation control. Adequate by -pass condensers are used at all necessary points in order to keep radio frequency currents in their proper places. The output of the detector is fed into a 3 -stage audi -frequency amplifier, having a power Wiring diagram of the RS -tt receiver. N O. 543 The "Transceptor" A New 5 -Meter Portable By Frank Lester, W2AMJ

THE transceiver, which has been extremely popular in the 5 -meter field, suffers from one serious shortcoming which becomes more and more objectionable as the user becomes more proficient in 5 -meter technique. Inasmuch as the same antenna is used for both transmitting and receiving. and practically all of the other parts of the instrument likewise serve a deal purpose, some compromise in adjustment becomes unavoidable. This is especially true of the extremely important adjustment of antenna coupling. The best coupling for transmitting unavoidably proves too tight for receiving purposes, and prevents the receiving portion of the transceiver from super-regenerating properly. new Some intermediate value of coupling must be chosen which will Above -The "Transceptor " -a permit the circuits to function in both the receive and transmit 5 -meter transmitter -receiver of the combinations; this means that the transceiver rarely gives the portable type shown in use by Mr. best performance of which it is capable. Lester. Photos at right show set In an effort to improve this situation and at the same time to closed up and below -a rear view, re- preserve the highly desirable features of compactness and porta- vealing the chassis. No. 544

S-25MMr 30 20NE4S PI PC 19 T3 bility which have made the transceiver so widely accepted, the writer has designed a new 5 -meter portable rig which is known as the Lafayette t "Transceptor." This instrument represents a logical advance in portable 5- meter practice, and evolved from the experience gained in the building of hundreds of transceivers, which are giving excellent performance in many parts of the world. 15 This new "Transceptor," which is shown in the accompanying illustra- APT w tions, measures only 15x15 inches MOMS (GMO square, by 7?_ inches deep, and is VOL e0HT110E rr í35v therefore just a trifle larger than a 200 HO; /a+ portable typewriter. Unlike all pre- ,y,r ói.00á vious transceivers, this is fitted with a hinged cover which fully protects Hook -up of the new 5 -meter transmitter- receiver tuning con- (Continued on page 171)

Names and addresses of manufacturers of apparatus described on this and following pages furnished upon receipt of 3 -cent stamp; mention No. of article.

www.americanradiohistory.com I5' SHORT WAVE CRAFT for JULY, 1936 NEW APPARATUS FOR THE "HAM" I. F. WAVE TRAP, II -49 POWER TYPE SWITCH, MANY amateurs and short -wave H -51 experimenters have experienced THIS new Ohmite switch, as difficulty in reception due to code can be seen in the photo, has 7 interference coming into the re- heavy duty contacts and is applic- ceiver at the intermediate fre- able to band switching, in trans- quency. This new Aladdin high mitters, or as a selector switch of permeability wave-trap is designed any type where considerable rf. to minimize this type of interfer- power is being handled. The base ence. In many cases, where the is an all porcelain vitreous enam- interference is coming in directly elled unit, to which are fastened over the antenna system, connecting the heavy straps. The moving this device in aeries with the an- contact consists of a special graph- tenna will eliminate the interfer- ite shoe which was developed ence. The wave trap is tuned to particularly for this purpose. the interfering signal. PIEZO ELECTRIC CALI- High Power Switch -II -51 BRATOR, H -52 SECTIONAL CABINET THE amateurs are at last pro- RACK, H -50 vided with a portable Piezo-Elec- tric Standard by which they may has been a long -felt THERE check frequencies from 100 kc. to desire among amateurs and 20,000 kc. in 100 kc. steps and builders of public address systems 1.000 1w. to 50,000 in 1.000 kc. steps for a cabinet type rack which can with an accuracy of a .05 per cent be up in sections. Starting built of 100 kc. and 1.000 kc. This in- a fundamental unit, the out with strument is complete as shown in constructor may add sections as the the photo and includes power sup- Piezo -Electric Calibrator -H -52 size and scope of the apparatus is ply crystal and the 955 Acorn Tube. increased. The basic unit is shown It will operate from a 110-120- the the base of which in photo volt, 50 -60 cycle, A.C. source; or measures 20x15 %x2t,_ ", and the top operation. this for un-mtalulated if de- 20x14'axl' ¡ ". To construct sired, operated rack, two may be front a 90- single complete panel D.C. the back 135-volt plate supply. sectional side avails and This R.C.A. crystal -controlled cal- of the same height of the panel New Style Rack -H -50 ibrator offers a compact and use- sectional side walls are used. The ful unit for the amateur. and backs are available in standard panel dimensions of which there are ten different sizes. TRANSMITTING AND RE- To make a multiple rack, it is CEIVING RF. CHOKES, only necessary to add additional 11-53 side walls and hacks of the same SEVERAL new transmitting and height as the panel which is being receiving rf. chokes have recent- used. ly been introduced by the J. W. This I.C.A. cabinet should inter- Miller Co. In the photograph we Transmitting and Receiving (Con fin nad poor 1614) I.C. Wave- trap -II -19 est our "Ham" readers. on R.F. Chokes. New 5 -Tube A.C. -D.C. Super -Het Has Dual Range

and 178 Gt.- .cn meters in the second band. The long wave model, intended for European use, covers the wave length ranges of 178 -550 and 89 -2,142 meters. The circuit employes a class A pentode out -put, triode detector circuit, and the tubes employed are a 6A7, 6D6, 75, 43, and 25Z5. Complete shielding on all necessary parts is carried out in a design of this excellent set and the loudspeaker is a special 5" dynamic. The undistorted power output is 1 watt, and the set weighs but 11 pounds. An extra fine performance is given by this set, thanks to the use of multi- purpose tubes and a tone control switch is provided on the chassis also. A special antenna kit is available for use with this particular set or it can be used with a standard antenna of the doublet or other type. The antenna kit designed for use with this set employs the doublet principle with a twisted pair lead -in. Rear view of the "dual- band" 5- The tube lineup. By referring to the diagram we see Front view of the new dual -hand, tube receiver; it has an out -put that a 6A7 pentagrid converter is used. This is followed 110 -volt A.C. -D.C. receiver. of 1 watt. by a 6D6 I.F. amplifier which, in turn, is followed by a No. 545. 75 duplex diode triode detector. This serves as the diode WITH a moulded bakelite cab- detector, and one stage of audio frequency inet of handsome appear- rectifier or amplification. To this is resistance, the new Pilot model "200" ance- coupled a 43 pentode which series double band receiver gets feeds the loud -speaker. Auto- matic volume control is incur - away to a "flying start." The set porated in this receiver, permit- has a very neat appearance and it tunes with very comfortable ting a fairly constant level re- sharpness; at the same time it ception of fading signals. gives very high quality output. There is also a tone adjust- This new receiver has an im- ment permitting either high or proved A.C.-D.C. circuit and low frequency reception. In the works on 110 volts, 60 cycles. A low frequency position this con- cabinet of bakelite measures trol reduces the ill effects of the 12%" high x 9%" wide and scratching and crackling nuises 6 916" deep. The front of the which sometimes accompany cabinet is decorated with heavy short -wave reception. chromium striping. A longwave This set is very economical model for use in European coun- and uses but 45 watts from the tries is supplied also with a range A.C. or D.C. lighting circuit. up to 2,142 meters. The stand- Interesting circuit diagram of the "dual- hand" receiver: This article has been prepared ard model covers the wave length the five tubes give superior performance, due to the use from data supplied by courtesy range of 16 to 52 in one band, of several multi -purpose tubes. of Pilot Radio Corp.

Names and addresses of manufarturers of sets described on this and following pages furnished upon receipt of stamped envelope: mention No. of article.

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 153 The New HAMMARLUND "Super Pro" By Donald Lewis

This latest type receiver, suitable for the most critical "Ham" or "Fan." embodies all of the features one might ask for. The bands are switched "in" and "out" with a positive mechanism, the range being from 20 me. to 540 kc. The set works on 110 volts, 60 cycle Front view of A.C., and has many new features which the expert operator will like. the Ilammarlund "Super Pro" receiver which has a range of 20 mc. to 540 ko. (15 to 555 meters.)

cision specification of the professional kilocycles. A complete description of operator, advanced amateur and critical the switch will be given later on. listener -in. A well- designed superheterodyne, is, The receiver is known as the "Super in reality, a combination of two distinct Pro," and its features are numerous. receivers of specific design which, when For instance, there is an electrostatic- combined together, offer an unusually ally shielded input; a special silver - efficient radio receiving system. The plated five -band, eccentric -cam switch; first part of such a system is connected four air -tuned I.F. transformers; con- to the receiving antenna and selects tinuously variable selectivity; two and amplifies the incoming signal, de- tuned R.F. stages on all bands; three livering it to the first detector or mixer, audio stages; visible tuning meter; ac- where it is heterodyned by the local curately- calibrated tuning dial in mega- high frequency oscillator to produce cycles and kilocycles; band -spread tun- a new frequency called the intermediate ing dial; audio frequency gain control; frequency. radio frequency gain control; inter- The second part of the system is a mediate frequency gain control; select- complete and highly efficient radio re- ivity control; variable beat oscillator ceiver with fixed tuning, which responds control; tone control; speaker -phone to the signals of the intermediate fre- switch; send- receive switch; AVC- quency produced by the first unit. The View of the chassis of the 14 -tube receiver. Manual switch; CW- Modulation switch, tuning and all other adjustments on separate power -supply unit, etc. the "Super Pro" are fixed. Therefore, As mentioned above, the "Super it is obvious that its performance can AFTER months of painstaking re- Pro" incorporates a most unusual be more exactly controlled than in the search and study, the engineers of switching arrangement. This switch case of a receiver which must be tun- the Hammarlund laboratories have de- utilizes an entirely new design and was able over a relatively wide frequency veloped and designed an amateur -pro- chosen since it proved to be absolutely range. Generally speaking, most of the fessional superheterodyne receiver that fool -proof, noiseless, and exceedingly gain and selectivity of the entire re- is replete with unusual features. It has effective throughout the entire band of ceiving system are obtained from this been designed to meet every rigid pre- frequencies from 20 megacycles to 540 fixed tune (Continued on page 167)

15,. R.F. 2.m R . DET ".FOSC. /53 1.F 23631.F 76e.I.F 2no.DET 152 A.F DRIVER -A.F. OUTPUT 6D6 6D6 6A7 6C6 6D6 606 6D6 687 76 42 42

r.. °1, 3DMu+ERs ____-I© 095 6 53321

Viring diagram of the 14 -tube "Super Pro" receiver, which possesses the salient features demanded by the expert short -wave "1lam" operator or the critical S -W Listener.

www.americanradiohistory.com JULY, 1936 154 SHORT WAVE CRAFT for Nows -- --asts !THE RADIO !----..-..---...----.....__..__...---..!Ca ,e Geo. W.Shuart Radio Amateur Course rangement. This tap should be varied 'PHIS lesson of our "Amateur ELEVENTH LESSON the to a exactly the same as suggested for Course" will be devoted entirely tickler turns in diagram 1. discussion of simple receiver circuits, In the eleventh lesson of our the -backs, In Fig. 3, we endeavor to show in so far as various types of feed simple short -wave re- proper connections for plate and cath- regeneration controls, and many other Course coils are The the- ode feed -back where separate minor details are concerned. ceivers are discussed. The inter- used. For instance; starting at the top ory of the circuits will not be dis- the two in pre- such as "band - of the coil form, and providing cussed, because this was given esting items windings are both wound in the sanie vious lessons. spread," "regeneration,' a n d direction, we have the terminal going The most important consideration in and grid - is the to the grid or grid condenser simple regenerative detectors "methods of coupling" are clearly leak. This is the grid coil, the lower by which regeneration is ob- "B" method number explained. terminal of which connects to the tained. This may be done in a negative of ways. The two most prominent are feed -back method, as shown in the plate shown Feed -back Connections Important Fig. 1, and the cathode method, Now for plate feed -back, the B plus in Fig. 2. the top of the tickler and the regeneration of any connects to Controlling either by the plate of the tube to the bottom. receiver may be accomplished If we are using cathode feed -back with in voltage of one of the ele- a variation the de- this coil, the top connection of the tickler ments of the tube or by varying will go to the cathode, and the bottom of feed -back coupling. In Fig. 1, gree condenser connection will go to the B negative. we show both the throttle We trust that the reader will famil- of regeneration which is indi- control the variation iarize himself with the above statements cated by condenser "C ", or T111 regarding coil connections. It is sur- of plate voltage by the potentiometer prising the number of mistakes made in "R ". For any detector circuit using :A.I.Voi coils. optimum range of the connection of the a triode there is an Going back to Figs. 1 and 2, we find within which the detector = plate voltage S that the grid -leak is shown both across operates most efficiently and smoothly. and directly from grid both the re- --.- the condenser It is strongly advised that to "B" negative; each has its advan- and condenser "C" be em- _ t ! the sistor "R" Resistor tage. The grid -leak being across ployed to obtain best results. condenser is not a parallel shunt to the may be a part of the power supply, losses. "R" regeneration tuned circuit and introduces no and when once adjusted However, it can easily be seen, and may be further controlled with the when the plug -in The number of many will recall, that throttle condenser "C ". inn. coil is removed the grid circuit is open important. No FIG 2 tickler turns is also very and in nearly all cases a tremendous definite rule can be given for the num- result. Connecting turns which will work howl or hum will ber of tickler If the grid -leak directly from grid to the satisfactorily for all conditions. "B" negative side of the circuit, in- throttle condenser "C" has a maxi- elim- the tickler ::. stead of across the grid condenser, mum capacity of 140 mmf. the inates this irritating occurrence of noise. turns should be adjusted simultane- e B+ (c) there will be no noticeable plate voltage for maxi- Practically, ously with the e P (B-) decrease in efficiency of the detector be- sensitivity, with the plates of FIG 3 offers mum meshed. cause the resistance is so high it your condenser "C" about s/a extremely small losses in the tuned cir- will allow smooth control of re- believes This per cuit. Therefore, the writer generation with the remaining 25 that it is the most logical connection. cent of the capacity of the condenser. An example of what might happen - `-1 Band- spread Problem a situation which in many cases : C: C2 and from Band -spread has always been a con- has prevented the experimenter siderable problem and dozens of meth- obtaining a high degree of sensitivity ods have been put forward. In Fig. 4, in the receiver follows: For instance, FIG we have the parallel condenser ar- suppose the tickler turns were consid- angement which consists of a fairly erably greater than the number neces- which is with a large tuning capacity "Cl" sary to bring about oscillation I/..^...\ used for setting the range of the smaller plate voltage of say 45. This would condensers "C2 ". For a fair degree of mean that the voltage on the plate would is 140 mmf., below band -spread when "Cl" have to be reduced considerably "C2" should be around 20 to 35 mmf. this value in order to stop oscillation, the de- tube However, with this arrangement thus resulting in operation of the 1cL f2 gree of band -spread is not the same for at a plate voltage which does not per- ". In other holds different settings of "Cl mit maximum sensitivity. This words, the band -spread is considerably true with the screen -grid detector as FIG.5 setting the greater when "Cl" (the band- shown in Fig. 2. In this case, condenser) is at maximum capacity than screen voltage is the critical potential. In the above drawing we show various "C -1" is at minimum. This cathode methods of obtaining regeneration and it is when The diagram shown employs the can be overcome with the arrangement tap, or so- called electron -coupled ar- hand -spread tuning.

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 155

OUTPUT PLATE DÉT 1R.FC.C3 /1

FIG.9

tbove-e have the audio coupling arrangement used in the average short -wave receiver, together with a complete workini, model diagram, embodying the various features discussed in this lesson,

shown in Fig. 5. Here we have "C -1" usually proportioned to provide maxi- shown in Fig. 3, with the addition of the the regular band- setting control, and mum efficiency over the entire tuning connections for the plate coil, which "C2" the band -spread unit, with an- range of that particular grid coil. The are exactly as indicated in the diagram. other large condenser similar to "Cl" The top of this coil is connected to the in series with it. This condenser is plate, i.e., the terminal nearest the grid "C -3 ". By proper adjustment of "C3" The next lesson of the "Radio end of the grid coil, and the other ter- and "Cl ", exactly the same amount of minal of the plate coil is connected to band -spread may be obtained at any Amateur Course" will be a con- the "B" plus. point of the entire tuning range of the tinuation of the receiver discus- circuit. For great band -spread, "C3" Coupling Detector to Audio Stage will have a small amount of capacity and sion. Coupling the plate circuit of the de- for a small amount of band -spread tector to an audio stage may be done "C3" will he increased in capacity. either with a transformer or through This undoubtedly is the most satis- connections of a coil of this type, hav- the use of resistances and condensers. factory method of the two, if a con- ing three windings, all wound in the In Fig. 9, we have the resistance -ca- stant band -spread ratio is to be main- same direction, will be identical to those pacity coupling, which is usually em- tained. ployed with pentodes. For triodes, such as the 56 for example, or some battery - Coupling R.F. Stage to Detector operated triode, then resistor "Rl" and Coupling the R.F. stage to the de- "R2" would be replaced respectively by tector also provides a number of prob- the primary and secondary of a trans- lems. Undoubtedly the most satis- former and condenser "C3" would be factory for general use is the inductive eliminated. In many cases where addi- method. However, each will be dis- tional audio amplification may be de- cussed so that the reader has a clear sirable with pentodes, resistor "Rl" picture of just what they consist of. may be replaced by a high-impedance In Fig. 6, we have the original method choke coil; one having an inductance which was used many years ago; the from 300 to 700 henries is entirely satis- so- called tuned impedance coupling. The factory. It may also be found neces- tuned circuit between the detector and FIG 6 sary to connect a r/ meg. resistor across R.F. stage is connected in the plate cir- B+ the A.F. choke in order to stabilize the cuit of the R.F. stage. And in this case, 100 circuit. the grid -leak must be connected be- MMF. ) Resistance coupling, as shown in Fig. tween the grid and the "B" negative 9, may be used for triodes as well as for best results. This method, of pentodes. In this case, "Rl" would be course, does not provide a good match anywhere from 50,000 to 100,000 ohms. between the two tubes, and is usually RFC. 250,000 ohms is the proper value for fairly broad in response when the de- screen -grid pentode tubes such as the tector is in the non -oscillating condi- ' 57 and 58. tion. In this case, the tuning condenser The audio amplification of a simple rotor and stator both have high -volt- receiver offers no problem whatsoever. age applied to them and must be in- Here an indirectly heated cathode type + sulated from the metal panel, should tube is used. Bias is usually obtained one be used. In Fig. '7, we have an- by inserting a resistor in series with other variety of the same idea. How- B- g+ F G 7 the cathode, by- passing it with a high ever, in this case, we have incorpor- capacity low voltage condenser; in the ated the tuning condenser and coil in diagram these are indicated at "C4" and the grid circuit in the usual manner, "R2." The resistor, "R3," will depend and the plate of the R.F. tube is in size upon the type tube used. Con- coupled through a condenser directly to denser "C4" should have a capacity of the grid of the detector. Voltage is from 5 to 25 mf. Electrolytics fed having to the plate through an R.F. choke a working voltage of around 50 volts are coil. For general short -wave reception, iii entirely satisfactory. this usually consists of the Conventional The R.F. filter 2% mh. circuit shown in Fig. choke. 9, consisting of R.F.C., Cl, and C2, is In Fig. 8, we have the latest and really necessary for stable operation. most popular and, undoubtedly, the The most capacity of "Cl" should be about efficient method of coupling an .0001 mf., while that of "C2" is about R.F. stage to the detector or to provide .0005 mf., for the general short-wave coupling, for that matter, between any B+ FIG.9 bands from 45 to 200 meters. two tubes. Here we have the plate coil usually interwound In Fig. 10, we have endeavored to in- with the grid coil Various types of coupling between two corporate all the various features men - and the inductance of the plate coil is stages of a receiver are illustrated above. (Continued on page 178)

www.americanradiohistory.com 156 SHORT WAVE CRAFT for JULY, 1936 SHORT WAVE LEAGUE Here's Your Button HONORARY MEMBERS The illustration herewith shows the beautiful I)r. Lee de Forest design of the "Official" Short Wave League but- John L. Reinartz ton. which is available to everyone who becomes a D. E. Replogle member of the Short Wave League. Hollis Baird The requirements for joining the League are E. T. Somerset explained in a booklet. copies of which will be mailed upon request. The button meas- Baron Manfred von Ardenne ures .n inch in diameter and is inlaid in Hugo Gernsback enamel -3 colors -red, white, and blue. Executive Secretary Please note that you can order your button AT ONCE -SHORT WAVE LEAGUE supplies it at cost, the price, including the mailing. being 35 cents. A solid gold button is furnished for $2.00 prepaid. Address all communications to SHORT WAVE LEAGUE, 99 -101 Hudson St.. New York. SHORT WAVE SCOUT NEWS

O.L.P. Report from Freeport, Pa. Sunday, April 4, from 4:26 to 4:44 MOST of the short -wave stations are F..S.T., working on a frequency of 11.95 now on their summer wavelengths. mc. Announcements were made in English, PHI, Huizen, Holland, is back on 17.77 and were being well received until a CW meg. station came on the same frequency, blot- DJD on 11.77 meg. sending the evening ting out all signals. ETB was coming in North America program, together with QSA5, R7. DJC. On March 23, at 8:30 p.m., E.S.T., the England is using GSO 15.18 meg. in the new Colombian station in Cartagena, 4th transmission and GSP 15.31 meg. in HJ1ABP, "Radio Cartagena," on 9.60 mc., the 5th transmission. was heard very well. Announcements also The 20 -meter amateur band is now also made in English. very good. YV4RC, Caracas, heard on 23rd March JVN Nazaki, Japan, 10.55 meg. Comes with R8 signal, on a frequency of 7.45 mc. in about on R -ï to 8 on Mondays and and not on its usual wave of 6.37 mc. Thursdays at 4:00 to 5:00 p.m. On March 24, the Japanese station JVN, When tuning for Japan, remember that 10.66 mc. received, very weak and fading. they are a great distance away. Therefore, (Continued an page 191) you must tune very carefully and also Japan does not use the regular bands that the other countries use. You may tune them in very weak, but stick to them -tune carefully and you will be re- warded. SUV, Cairo, Egypt, has been heard several times the past month phoning England. They always use scrambled speech, called condition A. You have to tune them in before they start to talk to England, if you want to hear them with- $hort urtrague out inverted speech. IRY, Rome, Italy, phone almost every morning at eu a D.tukoto 911ee1i..1 about 10:00 a.m. They use Toafi ely,`Tlew°Jotit, in :Pe ilnileJ "Pronto, Pronto" when lie. working some one. Slat. of llmauca, t f.a Short `2Uaut Crape ANGELO CENTANINO, fa. e%eted Box 516, Freeport, Pa. Andreita O. Cloquell Delighted With "Scout Trophy" -3ohn lüller Editor, SHORT WAVE CRAFT: Report from Listening I wish to acknowledge receipt of the twenty - Post in Trinidad, B.W.I. a meniúec oP tf.i. P¢ayue. fifth "Scout Trophy." I was fortunate, indeed, WITH the approach of to have won this Trophy and wish to express spring, reception h a s a.. Vaasa wfuteof, lñu ceaiiicnta f.a. my thanks to the magazine's staff and compli- been somewhat erratic, but ment them upon the beautiful work of art, which teen of{ic.atfy. atria) anJ emulate.) to Wu, they have incorporated in this Trophy. It cer- on the whole quite good. tainly is worth all of those long nights I spent Morning reception of the 16 Jove. doing "DX," and 19 meter bands has I am proud and happy to be the first woman fallen off a bit, the Doyen- %ij,t/...y.eec who has won the Scout Trophy. I shall keep it stations not coming in all my life as my most honored possession. try I wish to advise you and all my friends both with their usual bang. The in and outside of the United States, that I am other bands have been no longer living in Arecibo, and ask you to steady and good. please take note of my new address at the bot- The highlight in t h i s tom of this letter. month's report of this Lis- Please find my photo of the Trophy and all - This is the handsome certificate that is presented wave tening Post was the recep- radio receiver herewith. tion of the Ethiopian Sta- FREE to all members of the SHORT WAVE ANDREITA O. CLOQUELL, LEAGUE. The full size is 9A ". Primavera St.. No. 22, Stop 20. tion, ETB at Addis Ababa 71" i Santurce, Puerto Rico. which was heard here on See page 190 how to obtain certificate.

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 157 World S -W Station List Complete List of Broadcast, and Telephone Stations All the stations in this list use tele- tions or other important data that you phone t r a n s m i s s i o n of some kind. learn Note: Stations through announcements over the air marked with a star * are or correspondence with the stations. the most active and easily heard stations Stations and transmit are classified as follows: C- at fairly regular times. Commercial phone. B- Broadcast service. Please write to us about any new sta- X- Experimental transmissions. Around -the -Clock Listening Cuide It i.. a gond idea to follow a general schedule during bright daylight, listen as far as wavelength in relation between 13 and 19 band is generally found best about 12 m. to the time of meters (21510 to 15800 kc.) from the day L+ concerned. until 7 a.m. (After The observance of these To the east of the dark, results above :15 meters simple rules will save time. listener, from about 4 p.m.- are usually much better than during daylight./ 5 a.m., the 19 -35 meter will be found From daybreak till 7 p.m. very pro - These general rules hold for any location in the and particularly ductive. To the west of the listener Short -Wave this same Northern Hemisphere. Broadcasting, Experimental and Commercial Radiophone Stations NOTE: To convert kc. to megacycles (mc.) shift decimal point 3 places to left: Thus, read 21540 kc. as 21.540 me.

31600 kc. W2XDU 20020 kc. DHO 18620 -BX- 9.494 meters kc. GAU 17760 kc. DJE 15660 kc. J V E ATLANTIC -C- 14.99 meters -C. 18.11 meters BROADCASTING NAUEN, GERMANY 16.89 meters -C. 19.16 m RUGBY, ENGLAND BROADCASTING HOUSE Works S. America. mornings Calls NAZAKI. JAPAN 485 MADISON AVE., N.Y.C. 11. Y.. daytime BERLIN. GERMANY Phones Java 3.5 a.m. Relays WABC daily 5 -10 p.m., 8:05.11 a.m. Sat., 19900 Sun. 12:30.5, 6 -9 P.M. kc. LSG 18345 kc. FZS 15620 kc. -C. 15.08 JVF meters -C- 18.35 meters 17760 -G 19.2 31600 MONTE GRANDE. kc. IAC meters kc. W8XAI ARGENTINA SAIGON. INDO -CHINA C- 16:89 meters NAZAKI. JAPAN -BX. 9.494 Phones Parle. early morning Phones U.S.. 5 4 meters Tests IrregulaIY. daytime PISA. ITALY am. & o.m. STROMBERG CARLSON CO. Calls ships, 6:30.7:30 a. m. ROCHESTER. N.Y. 19820 kc. 18340 kc. WLA 15460 kc. KKR Relays WHAM daily 7:30 am.. WKÑ 17741 kc. C 19.4 meters 12.05 a.m. -C- 15.14 motors -C- 16.36 meters HSP LAWRENCEVILLE, -C- 16.91 meters RCA COMMUNICATIONS. LAWRENCEVILLE. N. J. N. J. BOLINAS, Calls England. daytime Calls England. daytime BANGKOK. SIAM CAL. 31600 kc. W8XWJ Works Germany 4.7 a.m. Tests irregularly -BX- 9.194 meters DETROIT. MICH. 19680 kc. CEC 18310 kc. GAS 17650 kc. XGM 15415 kc. KWO 6:15 a.m.12:30 p.m., -C. 18.38 maws 2-5. -C- 15.24 meten 17 meters C- 19.46 meters 7.10 p.m. SANTIAGO. CHILE RUGBY. ENGLAND DIXON. CAL. Calls N. Y.. daytime SHANGHAI. CHINA Works Buenos Aires and Colom- Works London 7.9 am. Phones Hawaii 2 -7 p.m. 21540 kc. W8XK bia daytime 15370 13.93 18299 kc. YVR 17520 kc. DFB kc. *HAS3 B maten -e- WESTINGHOUSE ELECTRIC 19650 kc. LSN5 -C. 16.39 meters -C 17.12 meters 19.52 meters PITTSBURGH. PA. MARACAY. VENEZUELA NAUEN. GERMANY BUDAPEST. HUNGARY 6 -9 a.m.; relays KDKA HURLINOHAM,naARGENTINA Works Germany. mornings Works S. America near 9:15 a.m. Broadcasts Sundays. 9.10 a.m. 21530 kc. GSJ Calls Europe, daytime 18270 kc. 17510 kc. VWY2 15360 kc. ETA 19.53 meters -B- 13.93 meters -C 16.42 meters -C- 17.13 meters DAVENTRY 19600 kc. LSF KIRKEE, INDIA RE IC HSPOSTZE NSTRALA MT. CHIEF ENGINEER ZEESEN. GERMANY B.B.C. BROADCASTING G- 15.31 maters P. 0. Boa 283. ADDIS ABABA. Works Rugby 2.7 a.m. HOUSE. MONTE GRANDE, Works with Africa and test ir- LONDON. ENGLAND ETHIOPIA regularly 9 -10:15 a.m. INA Irregularly 17310 kc. W3XL Tab IrryularlARGENTy, deNlme -X 17.33 meters 15355 kc. KWU 21520 kc. W2XE NATIONAL BROAD. CO. 19480 kc. 18250 kc. FTO -C 19.53 meters -B- 13.94 meters GAD BOUND BROOK. N. J. DIXON. ATLANTIC BROADCASTING -C- 15.4 meters -C. 18.43 meters Tests Irregularly CAL. RUGBY. ENGLAND ST. ASSISE. FRANCE Phones Peelle Isla and CORP. Calls S. Anted.. daytime 485 Madison Ave.. N.Y.C. Works with Kenya. Africa early 17120 kc. WOO 15340 kc. DJ R Relays WABC 6:30 a.m. -12 n. morning C- 17.52 meters 18200 kc. G A W -B,X- 19.56 meters A. T. a T. CO.. BROADCASTING HOUSE. 19355 C 18.48 meten OCEAN GATE. N. J. 21470 kc. * G S H kc. FTM RUGBY. ENGLAND BERLIN. GERMANY Calls ships 13.97 meters -C 15.50 meters Calls N. Y., daytime 1:30 -3:30 a.m. DAVENTRY ST. ASSISE, FRANCE 17080 kc. GBC B.B.C. BROADCASTING Cell/ Argentine. morning._ 18135 15330kc.* W2XAD HOUSE. LONDON. ENGLAND kc. PMC 17.56 meters -B- 19.58 meters 6.8:45 am. 19345 kc. C 16.54 meten RUGBY. ENGLAND GENERAL ELECTRIC CO. PMA BANDOENG. JAVA Calls Ships SCHENECTADY, N. V. -B.C. 15.51 meters Phones Holland. early e. m. 21420 kc. WKK BANDOENG. JAVA Relays 16270 kc. WLK WGY 10 a.m.2 -C- 14.01 meters Calls Holland early a.m. 18115 p.m. AMER. TEL. & TEL. CO.. Broadcasts Tues.. Thur.. Sat., kc. LSY3 C 18.44 meters LAWRENCEVILLE, N. J. 10:00 -10:30 a.m. Irregular 16.56 meten LAWRENCEVILLE. N. J. 1531.0 kc. *GSP Calls S. America 8 a.m. -4 MONTE GRANDE. Phones B- 19.6 m p.m. 19260 ARGENTINA Arg., Brat.. Pero, daytime DAVENTRY kc. PPU Tests irregularly B.B.C., BROADCASTING 21080 kc. PSA C- 15.58 meters 16270 kc. WOG HOUSE. -C- RIO de JANEIRO. BRAZIL LONDON. 14.23 meters Works with France 18040 kc. GAB C 18.44 meters ENGLAND RIO DE JANEIRO. mornings 6 -8, 9 BRAZIL C 18.83 meters OCEAN GATE, N. J. -II P.M. Works WKK Daytime 19220 RUGBY. ENGLAND Calls England. kc. W K F Calls Canada, morning and early afternoon 15290 kc. LRU 21060 kc. WKA -C- 15.60 meters morn. and early attn. -B- 19.62 meters LAWRENCEVILLE. N. J. 16240 kc. "EL MUNDO" C. 14.25 maten Calls England, KTO LAWRENCEVILLE, N. J. daytime 17810 kc. PCV -C- 18.47 meters BUENOS AIRES. ARGEN- Celle England MANILA. P. I. TINA. S. A. 19200 .C- 11.84 meters Testing 7 am. -7 p.m. noon kc. ORG KOOTWIJK. HOL Calls Gel., Tokio and ships -C 15.62 meten Calls Java. 6.5 8.1130 a.m. 21020 kc. LSN6 RUYSSELEDE. BELGIUM a. m. 15280 kc. DJQ -C. 14.27 meters Works with OPL mornings 16233 kc. FZR3 B 19.83 meters HURLINOHAM, 17790 kc. *GSG BROADCASTING HOUSE ARB. -C. 18.48 meters BERLIN. Calls N. Y. C. 19160 kc. GAP B. 18.86 meters SAIGON. INDO -CHINA GERMANY 1 a m.5 P. N. DAVENTRY. 12:30 -7 am. -C. 15.68 meters B.B.C.. BROADCASTING Calls Paris end Peelle Idas RUGBY. ENGLAND HOUSE. LONDON. 15270 20860 kc. EHY -EDM Calls Australia. early ENGLAND kc. *W2XE am. 6.8:45 a.m. 9 am. -12 n. 15880 kc. FTK B- 19.65 meters -C 14.38 meters C 18.90 meters ATLANTIC BROADCASTING MADRID. SPAIN 18970 kc. ST. ASSISE. FRANCE Works S. America. mornings. GAQ 17780 kc CORP. .0 15.81 meters *W3XAL Phones Saigon. morning 485 Madison Av., N.Y.C. RUGBY. -B- 18.87 meters 20700 kc. ENGLAND NATIONAL Relays LS 1( Calls S. Alela, menInge BROAD. CO. 15865 kc. CEC WABC daily. 12 n. -4 p.m. 14.49 meters BOUND BROOK. N. J. Relays -C- 18.91 meters MONTE GRANDE 18890 kc. WIZ. Daily axe. Sun. SANTIAGO, CHILE 15260 kc. ARGENTINA ZSS 8 a.m. -4 p.m. GSI Tarts irregularly -C 15.88 meters Works other S.A. stations e 19.66 meters KLIPHEUVEL. S. AFRICA afternoons DAVENTRY. Works Rugby 6:30 a.m. -I2 n 17775 kc. *PHI B.B.C.- BROADCASTING 20380 kc. GAA B 16.88 meters 15810 kc. LSL HOUSE, LONDON. ENGLAND 14.72 meter. 18830 kc. PLE HUIZEN. HOLLAND C- 18.98 meters 12:15 -3:30 p.m. RUGBY, ENGLAND C 15.93 meters 7:30.9:30 am. daily except Tue. HURLINGHAM. ARGENTINA Calls Argentina, Braille BANDOENG, and Wed. Calls 15252 kc. RIM mornings JAVA Snail Calls Holland. early a. m. 1.2 p.m. Sun. and E . daytime -C. 19.67 meters TACHKENT. U.S.S.R. 20040 kc. Phones OPL 18680 kc. OCI 17760 kc. *W2XE 15760 kc. J YT RKI near 7 a.m. -C- 14.97 meters 16.06 meters -X- 19.04 meten LEOPOLDVILLE. BELGIAN C KEMIKWA -CHO. CHIBA. 15250 kc. W1XAL LIMA. PERU ATLANTIC BBROA CONGO Works various S.A. stations CASTING KEN, JAPAN -a- 19.67 meters Works with ORG In morning daytime CORP. Irregular In Id. afternel. BOSTON. MASS. 485 Madison Ave., N.Y.C. and early morning Irregular. In morning (All Schedules Eaten Standard Ti..)

www.americanradiohistory.com 1936 158 SHORT WAVE CRAFT for JULY,

15245 14600 kc. JVH 13380 kc. IDU 11870 kc. *W8XK 11413 kc. CJA4 kc. *TPA2 meters -B 25.26 meters -C- 26.28 meters meters .B,C- 20.55 meters. C. 22.42 -B- 19.68 NAZAKI, JAPAN ASMARA, ERITREA. AFRICA WESTINGHOUSE ELECTRIC DRUM M ON D VILLE. "RADIO COLONIAL" am. Works With Rome daytime & MFG. CO. QUE.. CAN. PARIS. FRANCE Phones Europe 4-8 Tests Australia Irregularly 12 m -1 am. PITTSBURGH. PA. with de la Radiodiffusion Broadcast Daily In evening Service Mon. and Thurs. 4 -5 p.m. 5.10:30 p.m. 98. bis. Blvd. Haussmnn 13345 kc. YVC Fri. till 12 m 4.55 -10 am. C- 22.48 meters Ralan KDKA 11200 kc. XBJQ 14590 kc. WMN MARACA. -X- 26.79 meters 15220 kc. *PCJ -C- 20.58 meters Calls Hileah d ytlmeLA BOX 2825. LAWRENCEVILLE, N. J. 11860 kc. YDB MEX. -B. 19.71 rosten .g. 25.29 meters MEXI00 CITY. N.V. PHILIPS' RADIO Phones England 13285 kc. CGA3 Irregular morning and afternoon N.I. R.O. M., EINDHOVEN. HOLLAND -C- 22.58 meters SOERABAJA, JAVA Tues. 3 -6 am. DRUMMONDVILLE. QUE.. (Sun.) 11050 kc. ZLT4 Wed. 7.11 am. 14535 kc. HBJ Sat. 7 p- m.1:30 am. CAN. Dally 10:30 pm. -1:30 a.m. -C- 27.15 meters Sun. g:30.7:30 am, -B. 20.64 meters Works London and Ships N. ZEALAND NATIONS, WELLINGTON. RADIO afternoons 11860 kc. GSE Phones Australia and England 15210 kc. *W8XK GENEVA. SWITZERLAND early a.m. Also broadcasts ir- Broadcasts Irregularly VPD -B- 25.29 meters -O- 19.72 meters 13075 kc. DAVENTRY. regularly on Sunday. 9.10 a.m. WESTINGHOUSE ELECTRIO LSN -X- 22.04 meters B.B.C.. BROADCASTING & MFG. CO. 14530 kc. SUVA. FIJI ISLANDS HOUSE, LONDON. ENGLAND 11000 kc. PLP PITTSBURGH, PA. C- 20.65 meters Deily cae. Sun. 1230.130 m -B -C- 27.27 meters 9 a.m. -7 p.m. HURLINGHAM. ARGENTINA BANDOENG. JAVA Relays KDKA Calls N.Y.C. 12840 kc. WOO 11855 kc. DJP Broadcasts Sat. 7 p.m.-1:30 23.56 meten -B.X- 25 -31 meters am.. Sun. 5:30 -10 a.m. C- HOUSE. 15200 kc. DJB 14500 kc. LSM2 OCEACi1GATE. N. J. BROADCASTING Also 2.7 am. daily .B. 19.74 metes C- 20.80 matera shIn BERLIN. GERMANY BROADCASTING E 12 n. -2 p.m. 10970 kc. OCI BERLIN GERMANY HC llls IRIo and Euripe daytime 12825 kc. CNR -C- 27.35 3.50 -11 a.m. -B, C- 23.39 meters IA, PERU DIRECTOR GENERAL 11830 kc. W9XAA 14485 kc. TIR -B- 25.38 meters Works with Bogota Col.. Telegraph and Telephone OF evenings 15180 kc. *GSO C- 20.71 meten Rabat, Bornees CHICAGO .B RICA Stations. FEDERATION CARTAGO. COSTA Broadcasts. Sunday. 730 -0 a. M. HS8PJ DASVENT Y Phones Con. Amer. & U.S.A. CHICAGO. ILL. 10955 kc. B.B.C., BROADCASTING Da Relays WCFL 6:30 a.m. -4 p.m.. 9X- 27.38 melare HOUSE. 12800 kc. IAC 9 p,m.12 m. BANGKOK. SIAM C. 23A5 meten LONDON. ENGLAND HPF ITALY Broadcasts 8.10:15 am. 3:40.5:45 p.m. 14485 kc. PISA, 11830 kc. W2XE -C- 20.71 maten Calls Italian ships. Mondego PAN. -B- 25.36 meters 10840 kc. KWV PANAMA CITY. matera 15140 kc. *GSF Phones WNC daytime 12780 kc. GBC ATLANTIC BROADCASTING C- 27.88 B CORP. DIXON. CAL. .0- AVE.. N. Y. C. Works with Hawaii eaninga DAVENTRY. 14485 kc. TGF RUGBY. ENGLAND 485 MADISON B.B.C.. BROADCASTING Cale ships Relays WABC 4 -9 p.m. HOUSE. LONDON. ENGLAND -C 20.71 maten 10770 kc. GBP 9 a.m. -12 n. GUATMALA kc. CT1GO GSN s WNCldaytAT.daytime 12396 11820 kc. C RUGBYS ENGLAND 15120 kc. *HVJ -B- 24.2 mater, B. 23.36 meters Calls kc. YNA PAREDE, PORTUGAL DAVENTRY Sydney. Austral. early a M. .B 14485 Sun. 10-11 :30 a.m., Tua.. B.B.C.. BROADCASTING VATICAN CITY -C- 20.71 meters Thur.. Frl. 1:00.2:15 HOUSE. ROME. ITALY MANAGUA. NICARAGUA LONDON. ENGLAND 10740 kc. *JVM 1030 to 10:45 a.m.. aeept Phones WNC daytime DAF Irregular. 12325 kc. 1 130 p.m.-1:30 am. .B,C- 27.93 meters Sunday -C- 24.34 meter* NAZAKI, JAPAN Bat 10.10:45 a.m. 14485 kc. HRL5 GERMANY Tues. and Frl. 2-3 p.m. _ NORDDEICH. 11810 kc. *HJ4ABA meters skips daytime .C- 20.71 Works German B- 25.4 15110 kc. DJL NACAOME. HONDURAS P. 0. BOX 50 10675 WNB Weeks WNC daytime kc. B,X. 19.85 meters 12290 kc. GBU MEDELLIN, COLOMBIA -C- 28.1 meters BROADCASTING HOUSE, C 24.41 maton 1130 am. -1 p.m 830.1030 LAWRENCEVILLE. N. J. BERLIN. GERMANY 14485 kc. HRF RUGBY. ENGLAND p.m, Calls Bermuda. daytime 5.45 -7.30 am. -C- 20.71 meten Calls N.Y.C.. afternoon TEG Works 11810 kc. *2R0 WNC daytimeeRAB T Y B 10670 kc. *CEC 15090 kc. RKI 12250 kc. .B 25.4 meters C- 28.12 meter' -C- 19.88 m .0 E.1.A.R. SANTIAGO. CHILE MOSCOW. U.S S.R. 14470 kc. WMF PARIS. FRANCE Vla Monelle 5 Broadcasts Thun.. Sua. 7 a.m. ITALY Phones Tashkent near -C. 20.73 meters Irregular ROME. e30 -9 p.m.. Deily 7 -7:15 P.m. relays RNE on Sundays LAWRENCEVILLE. N. J. 8:15.0 am., 0:15-11 a.m., II30 and p.m. 10 -II am. Phones England 12235 kc. TFJ am. 12:15 p.m.. 1:30-5 10660 kc. merning and alterne'', B.0 24.52 meters *JVN DJO -B,C- 28.14 meters 15070 kc. PSD REYKJAVIK. ICELAND 11795 kc. NAZAKI, JAPAN meters 14460 kc. DZH Phonos England morning, B.X- 25.43 motors -C- 19.91 Sun. 1:40 -2 p.m_ Phones Europe 3 -8 e.m. RIO DE JANEIRO. BRAZIL -C,X. 20.75 BROADCASTING Broadcasts Man and Thurs Bu r+6 R EI MT GERMANYMANY Calls TYA 3.4:55 p.m. 4.5 au.m. N.Y.,Eur nos Aires ZEESEN,GERMANY Z 12215 kc. Daily 12 m -I .. 4 -8 a.m. Works on telephony and tests .C. kc. WNC 3:45-5:45 am. PAROIS, FRANCE 11790 kc. W1XAL 15055 Works French Ships in morning 25.45 roman 10550 kc. WOK .C. 19.92 meten and afternoon B- 28.44 meten FLORIDA 14440 kc. GBW BOSTON. MASS. HIALEAH. .0 Daily 5:15 -6:15 p.m. LAWRENCEVILLE. N. J. Calls Central America. daytIM. 12150 kc. GBS Phones RUGBY. ENGLAND Sun. 5 -7 p.m. nights Calls U.S.A.. attener .g. 24.8 meten Aral.. Brow., Paru. 14980 kc. KAY RUGBY. ENGLAND Calla N.Y.C.. alterna. 11770 kc. *DJD -0- 20.09 meten 25.49 matera 10520 kc. VLK P. I. 13990 kc. GBA 8- MANILA, .0 BROADCASTING HOUSE. -C- 28.51 matees Phones Peala* Iola 12130 kc. DIE BERLIN. GERMANY SYDNEY. AUSTRALIA RUGBY. ENGLAND 24.73 meters Rugby. early am. Calls -C.X- I l :35 am. -4:20 p.m.: 4:50- Calls RE I ZEESEÑTZ MT. P.M. 14970 kc. LZA Buna Aires. late attern es GERMANY .0:45 -B.C- 20.04 meters Works phone and tests 10430 kc. YBG SOFIA. BULGARIA irregularly 11750 kc. *GSD -C 28.76 meters Tests irregularly till 11:30 aal. 13820 kc. SUZ -B MEDAN. SUMATRA on Sundays C- 21.71 meters DAVENTRY. 530 -630 a. m.. 730 -830 p. m. ABOU ZABAL. EGYPT 12060 kc. PDV .Q. meten B.B.C., BROADCASTING Works with Europe 11 a.m.- 24.88 HOUSE, LONDON. ENGLAND 14960 kc. PSF 2 HOLLAND kc. XGW p.m. KOOTWIJK. I 12 :15.5 :45 10420 meters Test 11:30 p. m. :30 a.m.. C. 20.43 iular p.m., 6 -6. 9 -11 p.m. -C- 28.79 meter, RIO de JANEIRO. BRy1ZIL 13690 kc. KKZ SHANGHAI. CHINA Works with Buenos Aires 12000 kc. RNE Calta Manila and England, 8 -9 daytime -C- 21.91 metan 11730 kc. PHI late amine COMMUNICATIONS B- 25 meten 25.57 meten a. m. and Californie RCA MOSCOW. U. 8. S. R. BOLINAS. CAL. 12:30- HUIZ'N. HOLLAND 14950 kc. HJB Tests irregularly Sun. 6.9. 10.11 a.m.. kc. PDK 6 p.m.. 9 -10 p.m. 10410 .5. -C- 28.80 maten COL. Wed. 6 -7 a.m. BOGOTA. 13635 kc. SPW 12:30 -6 p.m. 11720 kc. KOOTWIJK, HOLLAND Calls_WNC. daytime Dally *CJRX 700.9:40 a. m. -B- 22 meters -B- 25.8 meters Calls Jam WARSAW. POLAND 11991 kc. FZS2 WINNIPEG. CANADA 1 II :30 a.m. - kc. KES 14940 kc. HI Mon., Wed.. Fri. .C 25.02 meten Dally. 8 p. m.12 m. 10410 20.08 meters 12:30 p.m. -X- 28.80 meters .C- at other times SAIGON. INDO-CHINA CIUDAD Irregular Phones 11715 kc. *TPA4 BOLINAS, CALIF. daytime Tests esenlnes hPhones WNC -e- 25.61 motets 13610 kc. JYK 11955 kc. ETB 'RADIO COLONIAL" 10350 kc. LSX HJA3 22.04 motets -C- 25.09 meten PARIS. FRANCE 14940 kc. -C- 28.98 meters 20.08 meters KEMIKAWA -CHO, CHIBA- ADDIS ABABA, ETHIOPIA 5:15.9:15 p.m. -C- C. p.m. -I2 m. MONTE GRANDE, BARRANQUILLA. COL. KEN. JAPAN See 18270 ke, 9:45 ARGENTINA daytime Phones California till II p. M. Works WNC Tests Irregul p.m. -12 mid - K K Q 11680 kc. KlO rlyh8. 13585 kc. GBB 11950 kc. -X- 25.68 matera 14845 kc. OCJ2 .X. 25.10 -C- 22.08 malen KAHUKU. HAWAII 10330 kc. O R K C- 20.21 meters ENGLAND BOLINAS. CALIF. Tats In the *venin, LIMA. PERU RUGBY. Tests. Irregularly. emalaga -B -C- 29.04 meters C.11a BELGIUM Works other S.A. stations Canada 11595 kc. VRR4 RUYSSELEDE. daytime Egypt & anouei Broadcasts 190.3 p.m. FTA -C. 25.87 metro 11940 kc. HILL. JAMAICA. 13415 kc. GCJ 25.13 meters STONY 10300 kc. LSL2 14653 kc. GBL .0 -C- B. W.1. STE. ASSISE. FRANCE Works WNC daytime. C- 29.13 asters .C. 27 ma RUGBY. ENGLAND Phones CNR morning. HURLINGHAM. ARGENTINA RUGBY. ENGLAND Calls Japan S Chip early Hurlingham. Arne.. nights Calls Eureno. aenlnn Works JVH 1.7 am_ me nine 11560 kc. VIZ3 DZC TYF 13390 kc. WMA 11880 kc. *TPA3 AMALGAMATED WIRELESS 10290 kc. 14640 kc. OF -X- 29.15 meters -C- 20.49 meters -C. 22.40 meth -B 25.23 mater* AUSTRALIA ZEESEN, PARIS. FRANCE LAWRENCEVILLE. N. J. "RADIO COLONIAL" FISKVILLE. PARIS. FRANCE Calls Canada evening and early GERMANY Work, Saigon and Cain 3 -7 Phones England Broadstsca irregularly 5 p.m. am.. 12 n. -2:30 p.m. menin and alternes 1.4 a.m.. 10:15 a.m.-

(All Schedules Eastern Standard Time)

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 159

10260 kc. P M N 9675 kc. DZA 9540 kc. *DJN 7630 31.01 meters 8795 kc. HKV kc. ZHJ -B -C- 29.74 meters C -B 31.45 meters -B- 34.09 meten -B- 39.32 Motu. SANDOENG. JAVA ZEESEN. GERMANY B ROADCASTING HOUSE PENANG Africa and broad- BOGOTA. COLOMBIA MALAYA Calls Australia 5 a.m. Works with BERLIN. GERMANY Dally 7.1) am. casts 5 -7 p.m. Irregular; 6:30 p.m.12 m_ Broadcasts Sat. 7 p.m. I :30 12:30-3:50. 8:05-11 a.m., 4 :50- IMO S.C. II p.m. -1 A.M. (Sun.) Lm., Sun. 5:30.10 am. 10:45 p.m. 9650 kc. *CT1AA 8775 kc. PN I 7626 kc. R I M -B- 31.09 meters -C. 34.19 meten 10250 kc. LSK3 9530 kc. *W2XAF MAKABRER. CELEBES, -C 39.34 meters -C- 29.27 meten LISBON, PORTUGAL TACHKENT. U.S.S.R. Tues.. Thurs., Sat. 3-6 p.m. -B 31.48 meten N.I. NURLINGHAM, ARGENTINA GENERAL ELECTRIC CO. Phones Java *round 4 a. m. Works with Moscow early Calls Europ and U. S.. after- 9650 kc. DGU SCHENECTADY. N. Y. morning noon and evening Relays WGY 4 pm.l2 es. 8765 kc. DAF -C. 31.09 meters Sat. 12 n..12 m. 7620 kc. ETD -C- 34.23 10220 kc. PSH NAUEN. GERMANY meten .C. 39.37 m 29.35 Works with Egypt In afternoon NORDDEICH. GERMANY ADDIS C meten 9525 kc. LKJ1 Works German Ships irregularly ABABA. ETHIOPIA RIO DE JANEIRO. BRAZIL -B- 31.49 meten Ree 18270 ke. 9635 kc. *2RÓ JELOY, NORWAY 10170 kc. RIO e- 31.13 meter, a.m.. 11 8760 kc. GCQ 7610 kc. 5.8 am. -6 p.m. -C 34.25 meters KWX 29.5 meten E.I.A.R.. ROME. ITALY -C. 39.42 m C M., W.. F., 6.7:30 pm. RUGBY, ENGLAND BAKOU. U.S.S.R. Calle 8. Africa, afternoon DIXON, CAL Works with Money Tues.. Thurs., Sat. 6 -7:45 p.m. 9525 kc. CQN Works with Hawaii ete Philip- 10 pr,t. -5 a.m. -B- 31.49 pines. Java and Japan nights. 9620 kc. YDB MACAO. PORTUGUESE 8750 kc. ZCK 10169 kc. HSJ B- 31.19 meters CHINA B. 34.29 meters 7550 Mon, and Fri. 7-8:30 am. HONGKONG, CHINA kc. TI8WS -CX- 29.5 meters N.I.R.O.M. B- 39.74 meters BANGKOK, SIAM SOERABAJA. JAVA Relays ZBW "ECOS DEL PACIFICO" 4:30.10 am. 9510 Daily 11:30 p.m. -I:15 a.m. Tests 9 -10 Lm., Mon., Wed.. kc. *VK3ME Mon. and Thurs. 3.7 P. 0. BOX 75 PUNTA Thur. B- 31.55 meters am. ARENAS, COSTA RICA 9600 kc. CB960 Tues.. Wed.. Fris 6 -10 am. AMALGAMATED WIRELESS. Sat. 6.11 am. S p.m. -I2 m. 10140 kc. OPM -B- 31.25 meters Ltd. -C 29.39 meter SANTIAGO. CHILE 167 Queen St.. 8730 kc. GCI 7520 kc. K K H LEOPOLDVILLE. BELGIAN 9:30 p.m. on MELBOURNE, AUSTRALIA C 34.39 meten C 39.89 meters CONGO Dally en. Sun. 4-7 a.m._ RUGBY. KAHUKU. HAWAII Phones around 3 a.m. and I- 9600 kc. HJ1ABP Calls India 8 a m Works with Dixon and broad- 4 casts p.m. B 31.25 meters 9510 kc. *GSB irregularly nights P.O. BOX 37. -B- 31.55 meters 8680 kc. GBC 10080 kc. RIR CARTAGENA. COL. DAVENTRY. -C- 7510 kc. JVP C 29.76 meters II a.m. -1 p.m. 5 -II p.m. B.B.C.. BROADCASTING RUGBY, ENGLAND .B.C. 39.95 meten TIFLIS. U.S.S.R. Sun. 10 am. -I p.m.. 3.6 p.m. HOUSE. LONDON. ENGLAND Calls ship NAZAKI, JAPAN Works with Moscow early 11:30 p.m. -1:30 a.m.. 12:15- morning. 9595 kc. *HBL 5:45 p.m. 8665 kc. CO9J Q 7500 kc. R K I -B 31.27 meten -X 34.62 meters -C. 40 meten 10070 kc. EDM -EHY LEAGUE OF NATIONS 9510 kc. HJU CAMAGUEY. CUBA MOSCOW. U.S.S.R. . C. 29.79 meten GENEVA. SWITZERLAND B 31.55 meters 5:30.6:30. 8.9 p.m. daily Works RIM early am. MADRID. SPAIN Saturdays. 5304:I3 p. R NATIONAL RAILWAYS except Sat. and Sun. Works with S. America evenings Mon. at 1:45 a.m. BUENAVENTURA, COLOM- 7390 BIA kc. ZLT2 10055 8590 kc. YNVA -C 40.6 meters kc. ZFB 9595 kc. HH3W Mon.. Wed.. Fri. B -II p.m. -B 34.92 meters WELLINGTON. -C- 29.84 meters N.Z. -B 31.27 meters MANAGUA, NICARAGUA Works with Sydney 3 -7 am. HAMILTON. BERMUDA 9500 kc. PRF5 7:30.9:30 p. m. Phones N. Y. C. daytime P.O. BOX 117, PORT -AU- PRINCE, HAITI -B 31.58 meters 1.2. 7.8 p.m. RIO DE JANEIRO. BRAZIL 8560 kc. WOO 7380 kc. XECR 10055 kc. SUV Irregularly 4:45 -5:45 p.m. C 35.05 meters B- 40.65 meters -C. 29.84 meten 9590 OCEAN GATE. N. J. FOREIGN OFFICE. ABOU kc. HP5J MEXICO ZABAL. EGYPT 31.28 meters 9490 kc. XGOX Calls ships Irregular CITY. MEX. Works with Europe 1.6 p.m. B Sun. 8 -7 APARTADO 887. B- 31.61 meters p.m. PANAMA CITY. PANAMA NANKING, CHINA 8400 kc. HC2AT 10042 kc. DZB 11:45 am.I p.m.. 7:30.10 p.m. 6:30.8:40 a m.. Sun. 7:30. -B 35.71 meters 7281 kc. HJ1ABD -X- 29.87 meters 9:30 a.m. CAMILLA 877 -B 41.04 meters ZEESEN. GERMANY 9590 kc. *PCJ GUAYAQUIL. ECUADOR CARTAGENA. COLO. Works with Central America and -B. 31.28 meters 9450 kc. TGWA 8.11 p.m. Irregularly. evenings tests 7.9 p.m. N. V. PHILIPS RADIO B- 31.75 meten 8380 EINDHOVEN. HOLLAND MINISTRE de FOMENTO kc. IAC 7100 9990 kc. KAZ Sun. 7-8 p.m. GUATEMALA CITY, -C- 35.6 meten kc. HKE -C- 30.03 meters Wed 7.10 p.m. GUATEMALA Pies. Italy B 42.25 meten MANILLA. P.I. Irregular 6.11 p.m. BOGOTA. COL.. S. A. Tue. and . Works with Java Cal. aad ships 9590 Sun. 2 -S am. 8214 kc. HCJB Set 8.0 m.; MM. kc. *VK2ME & Thun. 830.7 p. m. early morning B- 31.28 meten -B- 36.5 meters AMALGAMATED WIRELESS, 9428 kc. QUITO, ECUADOR *COCH except Monday 9950 kc. GCU LTD.. 47 YORK ST. 31.8 meters 7.11 p.m.. 7080 kc. VP3MR B- 11 n.; 4 -10 p.m. -Co 30.13 tors SYDNEY. AUSTRALIA 2 B ST.. VEDADO, Sun. a.m.12 B 42.63 m RUGBY. ENGLAND Sun. 1.3. 5-9. 11:30 a.m.-I:30 HAVANA, CUBA GEORGETOWN. BRI. GUI. Calle N.Y.C. evealae p.m. Daily 8 a.m. -7 p.m. 8190 kc. XEME ANA. S.A. Sun. II a.m. -12 n.. B- 36.63 m Sun. 7:45.10:15 a.m. 9930 kc. HKB 9590 kc. *W3XAU 8:30 -9:30 p.m. CALLE 59. No 517 Mon. 3:45 -4:45 p.m. MERIDA, YUCATAN Tues. 4:45.6:45 p.m. C 30.21 meters l 31.28 meters Wad. 4:45 -7:45 BOGOTA. NEWTOWN 9415 kc. "LA VOZ de YUCATAN deeds p.m. COL, SQUARE. PA. PLV Thur. 5 -6:45 Phones Rio de Janeiro evenings Relaye WCAU 31.87 MERIDA p.m. -C motors 10 am. --12 n.. 6 m. Sat. 4:45.7:45 p.m. Daily II a.m. -7 p.m. BANDOENO. JAVA p.m.12 9890 kc. LSN Phones Holland around 9:45 am. 8185 kc. PSK 7074 kc. C 30.33 meters 9580 kc. LRX HJ1ABK NURLINGHAM, ARGENTINA 9330 kc. CGA4 C 36.65 meten .B- 42.69 meters -B- 31.32 meten RIO DE JANEIRO. BRAZIL CALLE, BOLIVIA, Calle New York, evening "EL MUNDO" C 32.15 meters Irregularly BUENOS AIRES. ARGENTINA DRUMMONDVILLE, CANADA PROG ROSO. IC UAL DAD 9870 kc. WON Testing Phones England Irregularly BARRANQUILLA, COLOMBIA 8036 kc. CNR Sun. 3 -6 p.m. c 30.4 meters -B- 37.33 LAWRENCEVILLE. N. J. 9580 kc. * GSC 9280 kc. GCB MOROCCO Phones England. menial -8- 31.32 meters C 32.33 meters Sunday. X230 -5 p. M. 7030 kc. HRP1 DAVENTRY, RUGBY. ENGLAND -B. 42.67 meters 9860 kc. *EAQ R.B.C., BROADCASTING Calls Can. A Egypt. evenings 7975 kc. HC2TC SAN PEDRO BULA. -B 30.43 meten HOUSE. LONDON. ENGLAND -B 37.62 meten HONDURAS P. O. Bea 951 6 -8. 9.11 p.m. 9170 kc. WNA QUITO. ECUADOR Reported on this and other waves MADRID. SPAIN C- 32.72 meters Thurs.. Sun. at 8 p.m. Irregularly in evening Dally 5:15.9:30 p.m.; 9580 kc. *VK3LR LAWRENCEVILLE. N. J. Saturday also 12 n. -2 p.m. Phone En.Iand, evening 7901 kc. LSL 6996 kc. PZH B 31.32 meter. -C 37.97 meten 9840 kc. Research Section. B 42.88 meters JYS Postmaster Gen'le. 9150 kc. YVR NURLINGHAM. ARGENTINA P. 0. BOX I8. 30.49 metan Dept, Calls Brazil, eight -X 61 Little Collins St.. C 32.79 meters PARAMIRABO. DUTCH KEMIKAWACHO. CHIBA - MELBOURNE. AUSTRALIA MARACAY. VENEZUELA GUIANA KEN. JAPAN 3:15.7:30 am.. except Sun. Works with Europe afternoons. 7880 kc. J YR Sun. 9:36.11:36 a.m. Irregular. B 4.7 a M. also Fr. 10 p.m. -2 a.m. 38.07 meten Mon. and Fri. 5:36 -9:36 p.m. 9125 KEMIKAWA -CHO. CHIBA - Tues. and Thur. 8:36 -10:36 am., 9800 kc. LSI kc. *HAT4 KEN. JAPAN 2:36 -4:36 pm. 9570 kc. -6. 32.68 meten 0- 30.01 meters *W1XK 4.7:40 a. m. Wed. 3:36 -4:36. 5:36.9:36 p.m. MONTE .B- 31.35 meters "RAD IO LA BO R." Sat. 2:36.4:38 p.m. GRANDE, WESTINGHOUSE ELECTRIC GYALI -uT. n 7860 kc. ARGENTINA B UDAPEST. HUNGARY SUX Teste_Irregularly & MFG. CO. -C- 38.17 meters 6976 kc. HCETC SPRINGFIELD. MASS. Sunday 8.7 p.m. ABOU ZABAL. EGYPT 9790 kc. Relays WBZ, 6 a.m. -12 m. Works With Europe 4.6 p.m. B 43 meters GCW Sun 7 a.m. -12 m. 9060 kc. TEATRO BOLIVAR -O- TFK QUITO. ECUADOR RUGBY, ENGLAND -C- 33.11 meters 7854 kc. HC2JSB Thurs. till 9:30 p.m. Cells N.V.C.. evenlne 9565 kc. VUB REYKJAVIK, ICELAND -B- 38.2 meten -B- 31.38 meters Phenee London afternoons. GUAYAQUIL. ECUADOR 9760 kc. VLJ -VLZ2 BOMBAY. INDIA Broadcasts Irregularly. 8:15.11:15 pm. 6905 kc. GDS -C. 30.74 meters 11 a.m.1230 p.m.. Wad.. -C- AMALGAMATED WIRELESS Thun.. Sat. 9020 kc. GCS 7830 kc. YV9RC RUGBY. ENGLAND OF AUSTRALIA .0 -B- 38.31 meters CHI, N.Y.C. eveniag SYDNEY, AUSTRALIA 9560 kc. *DJA RUGB ENGLAND CARACAS. VENEZUELA Phones Java and N. Zealand -B. 31.38 metan Calls N.Y.C. evenings 7.11 p.m. 6900 kc. HI3C early a m. B ROADCASTING HOUSE. -B- 43.48 meters BERLIN 9010 kc. 7799 kc. *HBP LA RAMONA. 12:30 -3, KEJ 38.47 meten DOM. REP. 9750 kc. WOF 8:05 -II LOU.. 4:50- -C 33.3 meten B LA VOZdeR10 DULCE. 0- 30.77 meten 10:45 p.m. BOLINAS. CAL. 11:55 am. -1:25 p.m., 6:10 -7:40 LAWRENCEVILLE. GENAEVA. SWITZERLAND N. J. Relay, NBC & CBS p. m., Saturday p.m. Phone. England. evening 9550 kc .JH1ABE Programs In evening Irregularly B 31.41 meters 7715 kc. KEE 6860 kc. KEL 9710 kc. GCA P.O. BOX 31. 8975 kc. VWY C 30.99 meten -C- 38.89 meters 43.70 meters CARTAGENA. COLOMBIA -C- 33.43 meters BOLINAS. CAL. BOLINAS. CALIF. RUGBY. ENGLAND Daily 7:30.9 p.m.. KIRKEE. INDIA Relays Call Arge. & Brarll, evening. Mon. & CBS Tests Irregularly also 10 p.m.-12 m. Works with - Programs In England in morning NBevening irregularly II a, m..l2 n.; 6 -9 p. m.

(All Schedule, Eutern Standard Time)

www.americanradiohistory.com 160 SHORT WAVE CRAFT for JULY, 1936

6850 kc. T I6O W 6450 kc. HJ4ABC 6150 kc. HJ5ABC 6085 kc. 2R0 6030 kc. *HP5B meters B- 48.78 meters 49.3 meters O 49.75 meters .g- 43.8 meters B 46.51 B E.I.A.R. del CARIBE APARTADO 39 CALI. COLOMBIA P. O. BOX 910 ONDA -12 n.. Sun. 12 ROME, ITALY PANAMA PAN. PUERTO LIMON, COSTA (BAQUE, COLOMBIA Daily II am. CITY. RICA II a.m. -12 n., 8.11 p.m. 2 pm.. Daily eseept Sat. and 12 a. 10.m.. 7.10:30 p.m. Irregularly 8-9:30 p.m. Sun. 7.10 p.m. 6083 kc. VQ7LO 6447 kc. HJ1ABB B- 49.31 meters 6030 kc. VE9CA 6800 kc. HI7P 8- 46.53 meten 6140 kc. *W8XK NAIROBI. KENYA, AFRICA B- 49.75 meters -B- 48.86 5:45 -6:15 a.m., 1 130 CALGARY. -B- 44.12 meters BARRANQUILLA, COL., S. A. meten Mon.Fri. ALBERTA, CAN. EMISORIA DIARIA de COM- P. 0. BOX 715, WESTINGHOUSE ELECTRIC a.m.230 p.m. Also 8:30.930 Thun. 9 a.m. -2 a.m. (Fri.): -I 4:30 -10 p.m S MFG. CO. am. on Tues. and Thurs.: Sat. Sun. 12 n. -12 m. ERCIO. CIUDAD TRUJILLO. 11:30 Lm. p.m.; other DOM. REP. PITTSBURGH. PA. 11:30 Lm. -3:30 p.m.; Sun. Il on ther days from Relays a.m..2 p.m. 9 a.m. -12 m. Daily exc. Sat. and Sun. 12:40- 6425 kc. W9XBS KDKA p.m.; Sat. 12 -40- 9 pm.12 m. 1 :40. 6:40 -8:40 X. 46.7 meters 6020 1:40 p.m.: Sun. 10:40 a.m. - NATL. BROAD. CO. 6080 kc. CPS kc. DJC 11:40 a m. CHICAGO. ILL. 6135 kc. HI5N -B- 40.34 motors B. 45.83 meter* Relays WMAQ. Irregular -B. 48.9 meters LAPAZ. BOLIVIA BROADCASTING HOUSE, 6780 kc. HIH SANTIAGO. D.R. 7 -10:30 p. M. BERLIN 6:40 -9:10 p.m. 1135 a.m. -4:20 p.m. -B- 44.25 meters 6420 kc. H I1S 6080 kc. HP5F SAN PEDRO de MACORIS .8. 46.73 meters DOMINICAN REP. PUERTO PLATA. DOM. REP. 6130 kc. HJ4ABP B 49.34 meten 6020 kc. XEUW 12:10-1:40 p.m.. 7:30-9 p.m.. 11:40 a.m. -I:40 p.m.. 5:40- B- 48.94 meters Carlton Motel B 49.02 meter Sun. 3.4 am. 4:15-6 p.m. 7:40. 9:40.11:40 p.m. MEDELLIN, COL. COLON. PANAMA AV. INDEPENDENCIA. 98. Relays HJ4ABQ 8 -II p.m. 11:45 am. -1:15 pm.. 7:45.10 VERA CRUZ. MEX. 6755 kc. WOA p.m. 8 u.m. -12:30 Lm. 6410 kc. TIPG 6130 kc. TGXA -C- 44.41 meters 46.8 meten 6080 LAWRENCEVILLE, N. J. 8 APARTADO 225. B 48.94 meters kc. W9XAA 6018 kc. ZHI Phones England. ewping SAN JOSE. COSTA RICA GIORNAL LIBERAL PRO - -B. 49.54 meter. B 49.9 metro VOZ DE LA VICTOR" GRESSISTA. GAUTEMALA CHICAGO FEDERATION OF RADIO SERVICE CO.. "LA LABOR 20 RD.. 6750 JVT 12 n. -2 p.m.. 6.11:30 P.m. CITY. GUAT. ORCHARD kc. In evening CHICAGO, ILL. -B.C. 44.44 meters Heard the SINGAPORE. JAPAN Relays WCFL Men.. Wed. and Thur. 5:40-8:10 NAZAKI. 6380 kc. HI3U COCD Sunday 1130 a. m. -0 p. m. end a.m. Sat. 10:40 p.m. -1:10 am. KOKUS KAISHA. meters 6130 kc. B- 47.02 48.94 meters Tugs., Thurs., Sat., 4 p. m.1 m. (Sen.) Every errer Sunday 5:10. I-DE WA SANTIAGO de los CABAL- B 5:10 am. LEROS. DOM. REP. "La Vor del Alee" G 6079 kc. DJ M kc. a.m. -1:40 p.m., 4A0. CALLE y 25. VEDADO. 6710 *TIEP 10:40 HAVANA, CUBA 49.34 meten 6012 kc. HJ3ABH 44.71 meters 9:40 p.m. -B.X -B- Relays CMCD 11 a.m. -12 n.. 7- BROADCASTING HOUSE. 49.91 meters LA -VOZ DEL TROPICO -8- RICA 10 pm., Sun. 12 0. -4 p.m. BERLIN. GERMANY BOGOTA. COLO. SAN JOSE, COSTA 6375 kc. YV4RC 7:30.9:30 p.m. APARTADO 565 APARTADO 257. Dally 7.18 -B- 47.06 meters p.m. 6130 kc. ZGE 6.11 p.m. CARACAS VENEZUELA 6072 kc. OER2 Sun. 12 n. -2 p.m., 4 -11 p.m. 5:30.9:30 p.m. -B 48.94 meters 6672 kc. YVQ KUALA LUMPUR -B. 49.41 meters Meter. HIZ FED. MALAY STATES VIENNA. AUSTRIA 6010 kc. *COCO VENEZUELA 6316 kc. Sun.. Tue., and Frl.. 9 a. m. -5 p.m.. Sat. to 6 p.m. 49.92 metro MARACAY. B 47.5 mete B Broadcasts Sat. 8 -9 p.m. 6:40 -8:40 a. m. P.O. BOX 98 CIUDAD TRUJILLO 6070 kc. HJ4ABC HAVANA, CUBA DOMINICAN REPUBLIC Daily 9:30 a.m. -I p.m.. 4-7 p.m.. 6660 kc. *HC2RL Set. end Sun. 6130 kc. *CHNX ' B. 49.42 meten Deily except 48.94 meters PERIERA. COL. 8 -10 pan. -B- 45.05 meters 5:10.8:40 p.m.: Sat. 5 111 B Sat. also 11:30 p.m. -2 am. P. 0. BOX 759. GUAYAQUIL. Sun., 11:40 a P.O. BOX 998 9 -11 a.m., 7 -8 or 9 p. m. 11:10 p.m.: N.S., ECUADOR S. A. m. -1:40 P. M. HALIFAX. CANADA Sunday. 5:45 -7:45 9. M. Daily 9 a.m. -12:30 p.m.. 6070 kc. VE9CS 6005 kc. HJ1ABJ Tun.. 0:15 -11:15 R a. YV12RM 4.10 p.m. s 49.4: meters -B- 49.96 meters 6300 kc. Relays CHNS VANCOUVER. B. C.. CANADA MARTA. COLO. B- 47.62 meters SANTA 6650 kc. IAC VENEZUELA Sun. 1:45.9 p. m. 10:30 P. IL- 6.11 p.m. t Wed. 45.11 meten MARACAY. 6128 kc. HJ3ABX I a. m.; Tues. 6 -7:30 p. m., C. 8 P.M. PISA. ITALY -10:30 B 48.95 meters 1130 p. 111. -1:30 a. m. Dally Calls ships. evenings LA VOZ de COLOMBIA 6 -7:30 p. m. 6005 kc. HP5K 6280 kc. CO9WR CALLE 14. No. 738. B 49.96 meten 6630 kc. B 47.77 meters BOGOTA. COLOMBIA 6065 kc. HJ4ABL Box 33, HIT P.O. BOX 85. 5:45-11:30 p.m. COLON. PANAMA -B 45.25 meters -O 49.46 meten s.m.. 12 n. -I SANCTI SPIRITUS. CUBA MANIZALES. COL. 7:30.9 p.m.. LA VOZ de la RCA VICTOR," 4.6. 9.11 p.m. 6-9 p.m. APARTADO 1105, CIUDAD 6120 kc. *W2XE Dally 11 a.m.-12 n.. 5:30 -730 TRUJILLO. D.R. s- 45.02 meters p.m. Sat. 5:30 -10:30 p.m. 6005 kc. *VE9DR exc. Sun. 12:10 6280 kc. HUG ATLANTIC BROADCASTING Deily -1:40 p.m.. 49.96 meters 5:40.8:40 p.m.. also Sat. 10:40 -B- 47.77 meters CORP. 6060 kc. B. p.m. -12:40 am. (Sun.) CIUDAD TRUJILLO. D.R. 455 MADISON AVE., N. Y. C. *WSXAL CANADIAN MARCONI CO.. Relays WABC, 9.10 p.m. -B. 49.50 meters DRUMMONDVILLE, QUE., 7:10.8:40 Lm.. 12:40-2:10. RADIO CORP. 8:10.9:40 p.m. CROSLEY CAN. 6618 kc. *PRADO 6120 kc. XEFT CINCINNATI. OHIO Relays CFCF 6 am. -II p.m.. B 15.93 m 530 a.m. -7 p.m.: 10 p.m. -I a.m. Sun. 7 a.m. -9:15 p.m. ECECUADOR 6235 kc. HRD B- 49.02 meters Relays WLW Thurs. 9.11:45 p.m. B 48.12 meters AV. INDEPDENCIA 28, LA CEIBE. HONDURAS VERA CRUZ. MEX. 6000 kc. HJ1ABC 7:30 p.m. -12 m. W3XAU 5.11 p.m.. Sat. 8 p.m.-1 am. 11 a.m. -4 p.m.. 6060 kc. B 50 meters 6611 kc. RV72 (Sun.) Sat. also 6:30 -7:30 p.m. -B- 46.50 meters QUIBDO, COLOMBIA -B- 45.38 meters Sun. 11 a.m. -4 p.m.. 9 9.50.12 NEWTOWN SQUARE. PA. 5-6 p.m.. Sun. 9 -II p.m. MOSCOW, U. P. S. R. m. Relays WCAU, Philadelphia OAX4G Relays XETF 7 1.5 p. M 6230 kc. p.m. -I0 p.m. 5990 kc. B 48.15 meters *XEBT A and. 1242 6110 kc. VUC B 50.05 meters 6600 kc. HI8A 6060 kc. OXY MEXICO CITY, MEX. LIMA. PERU O 49.1 meters -B- 45.45 meters Dally 7 -10:30 p.m. CALCUTTA. INDIA -e- 49.50 meters P. 0. Bey 79.4 CIUDAD TRUJILLO. DOM. Wed. 6.1030 p.m. Daily Sat.. 3.530 a m.. SKAMLEBOAEK. DENMARK S a.m. -I Le. REP. 920 a woman: I -6:30 P-m. Irregular 6185 kc. H I lA Sat. II:45 a. m..$ p. M. 5988 kc. HJ2ABD 6050 kc. HJ3ABD -8. 50.10 meten -B- 48.5 meters BUCARAMANGA. COL. 6600 kc. H I4D P. 0. BOX 423. SANTIAGO. 6105 kc. HJ4ABB -B- 49.59 meten B- 45.45 meters 49.14 meters COLOMBIA BROADCASTING. 11:30 a.m. -12:30 m.. 5:30- DOMINICAN REP. B 6:30. p.m. CIUDAD TRUJILLO, DOM- 11:40 a m 1:40 p. m. MANI COL.. S. A. BOX 509. BOGOTA. COL. 7:30.10:0 INICAN REPUBLIC 7:40.9:40 9. m. P. 0. Bea 175 12 n. -2 p.m., 7 -II p.m.. Sun. Except Sun. 11:55 a.m. -1:48 Mee. to Frl. 12:15.1 p. M.; 5 -9 p.n,. 5980 kc. XEWI p.m.; 4:40.7:40 P.M. Tugs. IL Frl. 730.10 p. a.: -8- 50.17 meters 6180 kc. XEXA Sun. 2204 p. a. 6050 kc. H I9B MEXICO CITY. MEX. Non.. Wed.. Fri., 3 -4 p.m. 6560 kc. HI4V -B- -B- 49.59 meters DEPT. F EDUCATION 6100 kc. *W3XAL Tues.. Fri. 7:30 -8:45. 10 p.m.- -B. 45:73 meters CITY. MEX. SANTIAGO 12 Sat. 9 -10 Sun.l- MEXICO B- 49.18 meters REP. m.: p.m.: CIUDAD TRUJILLO. D.R. 7 -11 p.m. DOM. 2:15 P. m. LA VOZ de LA MARIN NATIONAL BROADCASTING Irregular 6 p.m. -11 p.m. 5:10-7:40 p.m. CO. 6175 kc. HJ2ABA BOUND BROOK. N. 1. 5980 kc. HIX Relays 6042 kc. HJIABG B- 48.58 meters WIZ B- 60.17 meters 6550 kc. TIRCC TUNJA. COLOMBIA Monday, Wednesday, Saturday, -B 49.65 metes CIUDAD TRUJILLO. -B- 45.77 meters 1.2; 730.020 9.m. 4-5 p.m.. Sat. 11 p.m. -12 m. EMISORA ATLANTICO DOMINICAN REP. RADIOEMISORA CATOLICA BARRANQUILLA. COLO. Sun 7:40 -1010; Dally 12:10- COSTARRICENSE 6100 kc. *W9XF 11 Lm.- II p.m. 1:10 p.m.. 4:40 -5:40 p.m.: kc. HJ3ABF I I 8 SAN JOSE, COSTA RICA 6170 a 48.18 motors Sun. Lm.- p.m. Tues. and Fri. 8:10.10:10 p.m. Sun. II . -2 p.m.. 6 -7. 9 -9 -B- 48 62 meters NATL. BROAD. CO. p.m., Daily 12 n. -2 p.m., 6.7 BOGOTA. COLOMBIA RIaye WEHR, Chime 6040 kc. W4XB 5976 kc. HJ2ABC p.m.. Thurs. 6 -11 p.m. 7.11:15 m. p. Sun., Tues., Thur.. Fri. 9 p.m- B- 49.67 meters -a- 50.2 meten 2 a.m.; M.. W.. Sat,. I -2 a.m. MIAMI BEACH. FLA. CUCUTA, COLOMBIA 6520 kc. *YV6RV 6160 kc. *YV3RC Relays WIOD 12 n. -2 Rm. 6 -9:30 p.m. -B 46.01 meters -B- 48.7 meten 6097 kc. ZTJ 620 p.m.-I2 m. VALENCIA. VENEZUELA CARACAS. VENEZUELA -8 49.2 meters 5970 kc. HJN 11 a.m.-2 p.m., 5.10 p.m. II a.m. -2 p.m.. 4.10:30 p.m. AFRICAN BROADCASTING -B 50.26 meten CO. 6040 kc. PRA8 BOGOTA. COL. JOHANNESBURG. SOUTH B- 49.67 meters 6.11 p.m. 6500 kc. HIL 6155 kc. COKG AFRICA. RADIO CLUB OF -B- 46.15 meters -B- 48.74 meters Sun. -Fri. 11:45 p.m. PERNAMBUCO PERNAMBUCO, BRAZIL 5968 kc. HVJ APARTADO 623 BOX 137. SANTIAGO. CUBA 1230 a.m. (next day) -B- 50.27 meters CIUDAD TRUJILLO. D.R. 9 -IO a.m.. 11:30 a.m. 1:30 p.m.. Mon. Sat. 330 -7 a.m. 1.3 Rm.. 4.720 p.m. dally VATICAN CITY (ROME) I 10 12 .11.- 9 a.m. -4 p.m. 12:10 - :40 a.m.. 5:40- 3 -430 P.m.. -II p.m.. 2.2:15 p. m., daily. Sun.. 5 -520 7:40 p.m. 2 a.m. Bun. 5.10:15 a.m.; 1230 -S p.m. 6040 kc. *W1XAL L M. -B 45.67 matra -. 6500 kc. HJ5ABD 6150 kc. CSL 6090 kc. *CRCX BOSTON. MASS. 5940 kc. TG2X B- 46.15 meters B. 48.78 meters B 49.28 meter. Tues.. Thurs. 7:15 -9:15 pm. -8 50.5 meten MANIZALES. COL. LISBON, PORTUGAL TORONTO. CANADA Sun 5 -7 p.m. GUATEMALA CITY, OUAT. 12.13 0 p. .. 7 -10 p. m. 7-8:30 a.m., 2.7 p.m. Dally 5:30 -11:30 p.m, 6 -6. 9.11 p.m.. Sun. 2-5 am. Sun. 11:45 a.m. -11 :45 p.m. 6040 kc. YDA 6451 YNLF 6150 kc. *CJRO -B. 49.67 meten 5930 kc. HJ4ABE kc. 50.59 meten -B- 46.51 meters -B 48.71 meter. 6090 kc. VE9BJ N.I.R.O.M. B- MANAGUA. NICARAGUA WINNIPEG. MAN., CANADA -a- 49.29 main TANDJONGPRIOK. JAVA MEDELLIN, COLO. 8 m. -12 m. SAINT JOHN. N. CAN. 5:45.6A5 p.m.. 1030 Rm. -I:30 Ddb I a.m.-12a -12 8 -9 a.m.. 1230 -2:30, 6:30 -10 P. L. PM. RM. P.m. Sun. 3 -10:30 p- m. 7.920 p. M.

(All Schedules Eastern Standard Time)

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 151

5900 kc. HH2S 5850 kc. *YV5RMO 5770 kc. HJ4ABD 5000 kc. TFL 4320 kc. GDB -B- 50.85 meters -B- 51.28 metas B- 51.99 meten .C- 60 meters .C. 19.44 sabre PORT -au- PRINCE, HAITI CALLE REGISTRO, LAS DE- LA VOZ CATIA. REYKJAVIK. ICELAND RUGBY. ENGLAND 7:30.10:30 p.m. LICIAS APARTADO de COR- MEDELLIN. COLOMBIA Calls London M night Tests. 8.11 p. M. RES 214 8 -11:30 p.m. _Also broadeuts irregularly 5885 kc. HCK II tmAÇ2 300p.m.E5.9 30Ep.m. 5720 kc. YV1ORSC 4975 kc. GBC 4273 kc. RV15 50.98 meters -B- 70.20 MOMS .8- B- 52.45 meten 80.30 maten QUITO. ECUADOR. S. A. VOZ de TACHIRA," -C- KHABAROVSK. SIBERIA, 5830 RUGBY. ENGLAND U. S. R. 8.11 p.m, kc. *TIGPH SAN CRISTOBAL. Cls 8hlp, lab at night S. B 51.5 meters VENEZUELA Daily, 3.9 am. ALMA 6.11:30 p.m. _ 5880 kc. YV8RB APLRAADO 800. 4820 kc. GDW -B. 51.02 meters SAN JOSE. COSTA RICA 5713 kc. TGS 4272 kc. WOO "LA VOZ de LARA" II a.m. -I p.m., 6 -IO p.m., -8- 52.51 metan C RUGBY. ENGLAND -C. 79.22 Metan BARQUISIMETO, Relays TIX 9 -10 p.m. GUATEMALA CITY. GUAT. Calls N.Y.C.. It at night OCEAN GATE. N. J. VENEZUELA ------Wed.. Thurs. and Sun. 6.9 p.m. - - Calls SBIp Irregularly 12 n.- Ip.m.. 6-I6 p.m- - 5800 kc. *YV2RC 5500 kc. TISHH 4790 kc. VE9BK - -BX- 62.63 meters 4098 ke. WND 5875 kc. HRN -B. 51.72 meters -B 54.55 meters RADIO CARACAS SAN RICA RADIO SALES SERVICE, -C. 73.21 matan -B- 51.06 meters RAMON, COSTA LTD., 780 BEATTY ST.. VAN- FLORIDA CARACAS. VENEZUELALA Irregularly 3:30 -4. 6 -11:30 p. m. HIALEAN. TEGUCIGALPA. HONDURAS Sun. COUVER. B.C., CAN. Calls Behama lelae 1:15-2:15. Sun. ens. Sun. 11:30-11:45 a. - - - -- 3:5:30, Dally IIe arm p.m., 4-9:304 -9:30 Daily -.. 3:30.5:30, 8:30-9:308:30 -9:30 p.m. 1:30 5145 kc. PMY m.. 3 -3:15. 8 -8:15 p.m. p m 58.31 B- meters - BANDOENG. JAVA 4002 kc. CT2AJ 5865 kc. HI1J 5:30 -II ..m. 4752 kc. WOO B- 74.95 meters 5790 kc. JVU _ PONTA DELGADA. B- 51.15 meters .C. MIGUEL, AZORES SAN PEDRO de MACOR Iß. 51.81 meters 5077 kc. N. J. SAO C- WCN OCEAN GATE. Wed. and Sat. 5.7 p. m. DOM. REP. NAZAKI, JAPAN C. 59.08 metan Calls ships Irregularly 12 n. -2. 6:30 -9 p.m. LAWRENCEVILLE. N. J. ------Phone, England irregularly 5780 kc. OAX4D 4600 kc. HC2ET 3040 kc. YDA meten 5853 kc. WOB .B. 51.9 meters 5025 kc. ZFA B 65.22 meters 8- 98.68 Apartado 249 N.I.R.O.M. -C- 51.26 meters P.O. Bea 653 -C- 59.7 meten JAVA N. 1. LIMA. PERU BERMUDA GUAYAQUIL. ECUADOR TANDJONGPRIOK, LAWRENCEVILLE, HAMILTON. -11 a.m. Calls Bermuda. night. Man.. Wed. & Sat. 0 -11:30 oren. Call. U.S.A. nights Wed., Sat.. 9:15 -11 p.m. 5:30

Alphabetical List of S -W Stations By Call -Letter and Frequency

(Frequency in Megacycles) P'Itl:Q. t V.I, Fltlill. ('\I.1, FI(I I \ I.I, FIitQ. l'\I,1, 1'ItEQ. ,1'\II, 1''11.NI1. I`\1,1, FREQ. ('\1.I, me. TPA3 11.88 me. W2XE 11.83 mc. CB960 9.06 un . FZS Is Vol HIH 6.78 nte. HSP 17.74 me. OER2 6.07 11.72 W2XE 6.12 CEC 19.6K FZS2 I I 99 HII 14.94 HVJ 1rì.12 OPL 20.04 TPA4 12.22 W3XAL 17.78 CEC GAA 311:914 HIL 6.50 NVJ 6.97 , OoM 10.14 TYA 6.10 CEC 1067 GAB 1/1 HIT 6.63 IAC 17.76 ORG 19.20 TYB 12.25 W3XAL 9.59 CGA3 1:3.29 GAD 1 IS MIX 5.98 IAC 12.80 ORK 10.33 TYF 14.64 W3XAU 6.09 W3XAU (1.06 CGA4 9.:3:3 GAP ni HIZ 6.32 IAC 8.38 ' OXY 6.II6 VE9BJ 17.31 CHNX 6.11 GAQ 5 97 HILA 6.19 IAC 11.11:5 PCJ 15.22 VE9BK 4.79 W3XL VE9CA 6.0:3 W4XB 6.04 CJA3 11.41 GAS S :t l HIU 5.845 IDU 13.39 PCJ 9.:19 j

6.07 I 6.06 CJRO 6.15 GAU H115 6.42 1 i2R0 11.81 PCV 17.81 VE9CS W8XAL CJRX 11.72 GAW 8 20 HI 3C 6.90 2R0 9.64 PDK 10.41 VE9DR 6.01 W8XK 21.54 CNR 12.83 GBA :t 99 HIM 6.38 JVE 15.66 PDV 12.06 VIZ3 11.511 WSXK 15.21 CNR 8.04 GBB L311 H14D 6.60 JVF 15.62 PHI 17.78 VK2ME 9.59 W8XK 11.87 6.14 COLD 11.1:3 GEC 7 05 HMV 6.56 JVH 14.11(1 PHI 11.73 VK3LR 9.58 W8XK COCH 9.43 GBC 178 HUSH 6.14 JVM 10.74 PLE 18.83 VK3ME 9.51 W8XWJ 31.110 11.83 6,01 GBC e 6d. JVN 10.196 PLP 9.42 VLJ 9.76 W9XAA COCO H17P 6.80 6.08 COKG 6.16 GBC -1118 HI8A 6.60 JVP 7.51 PLV 11.00 VLK 10.52 W9XAA CO9JQ 8.67 GBL I111L H 19B 6.05 JVT 11.75 PMA 19.35 VLZ2 9.76 W9XBS 6.43 CO9WR 6.28 GBP In 7' HJA3 14.94 JVU 5.79 PMC 18.14 VPD 13.08 W9XF 6.10 CPS 6.08 GBS 1215 HJB 14.95 JYK 13.61 PMN 10.26 VP3MR 7.08 XBJQ 11.20 CQN 953 GBU 12 29 HJN 5.97 JYR 7.88 PMY 5.15 VQ7LO 6.08 XEBT 5119 CRCX 6.09 GBW 1141 HJU 9.70 JYS 9.84 PNI 8.78 VRR4 11.191 XECR 7.38 9.57 19.12 CSL ü IS GCA 9.71 HJIABB 11.45 JYT 15.76 PPU 11.2 ; VUB XEFT .8.19 CT1AA 11.65 GCB 9:1.8 HJ1ABC 6.0 KAY 14118 PRADO 6.112 VUC 6.11 XEME CT1GO 12.40 GC! 8.73 7.28 KAZ 909 PRAB 6.01 VWY 8,118 XEUW 11.02 HJ1ABD 5.98 CT2AJ 4.111 GCJ 13.12 H11ABE 0.55 KEE 7.72 PRF5 9.501 VWY2 17.51 XEVI 5.014 11.18 12-._33 GCQ 876 NJ BG 6.04 REP 9.1)1 PSA 21.08 WCN XEXA DAF lA 1 DAF 8.77 GCS 11112 HJ1A6J 6.1)1 KEL 6.86 PSD I3.07 WKA 21.06 XGM 17.65 m; I WKF 1912 XGOX 9.49 DFB 1 7 5 2 GCU 9 95 HJ1ABK 7.117 KES 10.41 PSF II 10.42 DGU 1111311 GCW 97 HJ2ABA 6.18 K1O I168 PSH 1,, 22 WKK 21.-12 XGW s 10.43 DJA f1:ai0 GDB I 32 HJ2ABC 5.9% KKH 7 P5K s 19 WKN 19.82 YBG 11.04 DJB 15 20 GDS c!11 HJ2ABD 5.98 KKR I:,'III RIM G 2.i WLA 18.34 YDA 3.134 DJC (111 GDW I.u! HJ3ABD 6.(1.5 KKZ 13.69 RIM 7.6:3 WLK 16.27 YDA 11/.17 13.39 YDB 9.112 DJD 1 1 GSB 9.51 HJ3ABF 6.17 KTO 16.24 RIO WMA ': 11.811 DJE 17 71i GSC 9 58 HJ3ABH 19.01 KWO 15.42 RIR 10/18 WMF 14.47 YDB DJL 1:11 GSD 11.75 HJ3ABX 6.1:1 KWU 15:311 RKI 15.09 WMN 14.59 YNA 14.49 Iì.45 DJM 6 0 GSE 11 86 HJ4ABA 11.81 KWV 10.84 RKI ".31) ' WNA 9.17 YNLF DJN 9 SI GSF I:\11 HJ4ABB (3.11 KWX 7.61 RNE 11'JI WNB 10.68 YVC 13:35 DJO 1I8 GSG 17.79 HJ4ABC 6.45 LKJ1 11.3:3 RV15 4.27 WNC 15.01 YVQ 19.147 4.111 YVR 18.30 DJP I I 86 GSH 21.17 HJ4ABC 19.1)7 LRU 15 29 SPW 1364 WND DJQ I..28 GSI 15 !6 HJ4ABD LRX '1.5.8 SUV 10.111 WOA 6.76 YVR 9.15 5.84) DJR 15.3.1 GSJ 21.3:t 4A BE 5.113 LSF 11160 SUX 7.811 WOB 5.8.; YV2RC 0.16 DJT 15.36 GSN 11.81 4A BL 6.019 LSG 19.:1(1 SUZ 1:3.82 WOF 14 17 YV3RC DZA 9.1i% GSO IJ.Is HJ4ABP 9.60 L51 9.80 TFJ 1211 WOG III 211 YV4RC 0 .38 5.85 DZB 11114 GSP 13:31 HJSABC 6.15 LSK3 111.2:1 TFK 906 WOK 111.33 YV5RMO DZC 11119 HAS3 15.37 HJSABD 6.50 LSL 15.81 TFL 10 WON 11.87 YV6RV 6.52 DZE 12.1:3 HAT4 9 13 HKB 11.93 LSL2 111.30 TGF 1.1.49 WOO 17.112 YVSRB 3.88 7.83 DZH 14.411 HBJ 14.31 HKE 7.10 LSM2 14.50 TGS 5'1 WOO 1284 YV9RC EAQ 9.86 HBL 9 60 H KV 8.80 LSN 9.89 TGWA 0.45 WOO YV1ORSC 5.72 EDM 211.811 HBP 7.80 HPF 14.49 LSN 14.53 TGXA 11.1:3 WOO I : YV12RM 6.30 EDM 10.117 HC ETC 6.98 HPSB 6.03 LSN5 111.115 TG2X 5.91 WOO -127 ZBW 8.75 EHY 211.86 HCJB %11 HP5F 6.08 LSN6 21.02 TIEP 11.71 W1XAL 151:5 ZFA 5.03 EHY 10.07 HCK 5.811 HPSJ .1.50 LSX 10.35 TIGPH 5.811 W1XAL 11.79 ZFB 10.019 ETA 18.27 HC2AT 8.411 HP5K 6.01 LSY 20.70 TIPG 11.41 W1XAL 6.04 ZGE 11.13 ETB 11.96 HC2ET 4.1111 HRD 6.24 LSY3 18.12 TIR 14.49 W1XK 9.117 ZHI 6.02 ETD 7.62 HC2JSB 7.85 HRF 14.49 LZA 14.97 TIRCC 6.55 W2XAD 15.:33 ZHJ 7.63 FTA 11.94 HC2RL 6.66 HRL5 14.49 OAX4D 5.78 TISHH 5.50 W2XAF 9.53 ZLT2 7.39 FTK 15.88 HC2TC 7.9s HRN 5.88 OAX4G 6.23 TI6OW 6.85 W2XE 21.52 ZLT4 11.05 FTM 19.36 HH2S 5.111 HRP1 7.03 OC1 18.68 TIBWS 7.55 W2XE 17.76 ZSS 18.89 FTO 18.25 HH3W 960 HS8PJ 101)6 OCI 10.97 TPA2 15.25 W2XE 15.27 1 ZTJ 6.10 FZR3 16.23 HIG 6.2% HSJ 10.17 OCJ2 14.85

www.americanradiohistory.com 162 SHORT WAVE CRAFT for JULY, 1936 Short Wave

1043, ßia_ CONVERTING TERMS OUTPUT OUTPUT 58 ` ¡ F 5OOMMa ( TUBE TRANS. .,,--Irl 57 01 (245 Hummer Hart ley, Morgantown. 140 ' W. Va. ar. 4 a é J(^ `' (Q) Would you please i t" i OUT explain ' a y how ohms may be converted to meg- 0.I- I:j I.:uF tM44.1.14 ohms and mf. to mmf. MF 9 s d (A) One megohm is a million Yi ._ O.lL--#7x ohms; .5 megohm will naturally be T.....ms,.. x x million. The number being too I. á MECS 0.25- large to write. it is ` MEO. f designated as T f T a decimal or part of a megohm. '25,000 -- - 1- 0.2 ,ÑO 500 1,10th megohm is 100.000 ohms, OaMS MF r MEG F. OHMS MEG Y etc. If we had a condenser value indicated as 100 mmf. we merely V place a decimal six places B- 'gams') to the 2'1+0;10 left of this number. We would then have a .000100 3 -Tube receiver using 58, 57, 2A5. or .0001 mf. Connecting and Zeros to the right of the number earphones to out- are, of course, of no consequence. put tube. 3 -TUBE RECEIVER of a type 30 which may be trans- The reverse procedure is followed in visable former- coupled to your present re- converting the decimal to use a high voltage con- Seymour Levine. B'klyn, N. Y. ceiver. The back into a denser, (Q) I intend building a receiver primary terminals of whole number. Moving the decimal something having a work- the 3 to 1 audio con- ing voltage of from using a 58 as a radio frequency am- transformer six places to the right we again 600 to 1,000 nect to the o' the 1 volts, in order plifier, a 57 as regenerative detec- terminals -tube have 100 mmf. that no damage will set, which were formerly used as be done tor, and with a 2A5 audio ampli- to the earphones due to fier. I would appreciate very the earphone connections. This break down of the condenser. it should a considerable increase IMPROVING THE much if you would print the dia- give DOERLE" gram showing the in volume. proper connec- Robert Marshall, WHICH ANTENNA IS tions and the values of all parts re- New Bedford, BEST? quired. VOLUME CONTROL Mass. (Q) I have constructed William (A) The diagram using 57, 58, Hans Martin, B'klyn, Y. the Owens, Bangor, Pa. N. " Doerle" receiver 57 and 2A5 is shown. This set will (Q) I would using a and a (Q) I would like to know the di- like to know where 2A5. However, I would like operate a speaker on some of the I could connect a volume control to ob- ameter of the coil form used in to tain more volume, and would ap- the stronger stations, but for full speak- a 1 -tube receiver. article, "Which Short -Ware preciate it very much if you would Aerial is er volume a 56 should be connected (A) We do not believe a volume /test ?" Also. can the Mar- between the 2A5 print a diagram of the same re- coni type antenna be longer than and the 57 detec- control is necessary on a 1 -tube ceiver tor. set, for using a 57, 56. and 2A5. I 75 feet? remember a volume control would also like to know if only cuts volume down from the this (A) The coil form has a diameter maxim u m obtainable amount, and does not increase volume. In other words, a volume control is merely an attenuator.

P. A. CALLING SYSTEM Richard Sweeney, San Leando, Calif. (Q) I would like to construct an amplifier system which can be used in an office for calling various members of the staff to the telephone. I would like to use two tubes and a rectifier. if necessary. I intend operating this 'rom 110 volts A.C. and want to use a single- button microphone. Type 30 audio amplifier. (A) The diagram published uses a 56 and a 2A5 with an 80 in the Diagram of 3 -tube set using 57, 56, and 2A5. AMPLIFIER FOR 1 -TUBE power supply. Sufficient volume should be obtained to operate a receiver would be satisfactory for of approximately 2 3¡,". The 75 foot RECEIVER dynamic speaker. A volume con- 10 -meter operation. length for the Marconi antenna will Will Rogers, Minneapolis. Minn. trol is also incorporated in the first (A) We have shown the Doerle give best results; we do not recom- (Q) If possible. I would like to stage of amplification in order that circuit with the addition of a "56" mend that you change the size. add another tube, an audio ampli- the amplifier may be adjusted to first stage of audio amplification, do will fier, to the 1 -tube receiver which I the desired level. In the 11 negative hut we not think that you METAL TUBE AMPLIFIER obtain very good results on 10 already have. This receiver uses a circuit we have incorporated an John Rose, W. Toledo, Ohio type 30 as a detector. Would you on- meters. Past experiences have shown and -off switch which is independ- (Q) I built the 2 be kind enough that a good superheterodyne is nec- -tube metal to print the neces- ent of the primary switch. This receiver described by D. sary wiring essary on the 10-meter band. unless Harry diagram? B negative switch is used for put- Huoton on Page 718 of the April. (A) We are showing a diagram ting the amplifier into operation. you are only interested in local police calls, etc. 1936 issue, and would now like to add a pentode amplifier using a metal tube. Please publish the dia- CONNECTING EAR- gram in the "Question Bos." PHONES TO COMMERCIAL ALL - WAVE RECEIVERS Gerald Grandmaison, Salem, Mass. (Q) I have a commercial all -wave receiver and would like to know if there is any simple method by which I may connect earphones to it. If so, will you be kind enough to print the diagram in the "Question Box ?" (A) We are showing a diagram of one method of connecting earphones to of 50,000 the output amplifier OHMS any receiver. Merely connect a .1 V mf. condenser in series with a pair ro PHONE x of earphones. Then one side of the POSTS OF condenser is connected to the plate 2TUBE SET 6 63V of the output tube and the other connection of the earphone to the Pentode amplifier using metal Inter -office calling system. B plus or B negative. It is ad- tube.

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 163 QUESTION BOX Because the amount of work involved in the the form of stamps, coin or money order. drawing of diagrams and the compilation of Special problem. involving considerable re- data, we are forced to charge 25c each for let- search will be quoted upon request. We cannot ters that are answered directly through the mail. offer opinions as to the relative merits of eom- EDITED BY GEORGE This fee includes only hand -drawn schematic mercial instruments. W. SHUART, W2AMN drawings. We cannot furnish "picture-layouts" Correspondents are requested to write or print or "full- sized" working drawings. Letters not ac- their names and addresses clearly. Hundreds of companied by 25c will be answered in turn on letters remain unanswered because of incomplete this page. The 25e remittance may be made in or illegible addresses.

(A) The addition of a 6F6 pen- plug -in coils and a 140 mmf. con- tode amplifier to the 2 -tube re- denser, which I want to gang with ceiver should be a profitable under- the detector condenser. taking in so far as results are con- (A) The addition of an R.F. cerned. The diagram is clearly stage should greatly improve the shown. The two input terminals performance of the receiver men- of the amplifier connect to the tioned above. If the two condensers earphone posta of the 2- tuber. are ganged a trimmer having a capacity of approximately 50 mmf. or larger, should be connected across 2 -TUBE SET USING 76's the R.F. tuning condenser, in order to compensate for discrepancies in .1. Bailey, Pittsburgh. Pa. the circuit. (Q) Would you be kind enough to print a diagram of a short -wave receiver using one 76 as a detector, "2 EQUALS 3" DIAGRAM regenerative, of course, and an- Carl Smetka, Owosso, Mich. other 76 as a transformer coupled (Q) Will you publish in one of audio amplifier. This should use the coming issues of the "Question. 6F7 and 37 used as detector and two A.F. regular two-winding plug -in coils Box" a diagram of a 2 -tube re- which were illustrated in the Jan- ceiver employing 6.3 volt tubes METAL TUBE 1 -TUBER REDUCING VOLTAGE uary, 1936 "Question Box." and 4- two-winding plug prong -in George McEvenue, Ontario. Canada W. M. Warren, Wichita, Kansas. (A) The diagram you requested is coils? The tubes which I are prefer (Q) I contemplate building a re- (Q) I have a 600 volt power given and it should make an excel- a 6F7 used as a regenerative detec- ceiver using one metal I do supply and would like to reduce it to lent short -wave receiver. It is ad- tor, and one stage of audio tube. ampli- not know just which type tube will 400 volts in order to operate 53's visable to try different voltages on fication and a 37 as an audio ampli- give best performance, and I in class B. I am informed that a the plate of the detector in order to fier forming the second stage. The trust that you will publish the necessary resistor will not work properly. determine what voltage would give regeneration control should fie in information in the coming issue of What must I do to reduce the plate the "Question Box." voltage when the filaments are to be (A) There are two tubes which taken from the same transformers. will serve very nicely as a regenerative detector when working into a pair of earphones. They are the 6F5 and the 6C5. The 6F5 is the high -mu tube, and the 6C5 is the low -mu tube. Regeneration is controlled by a 140 mmf. throttle condenser. A.C.-D.C. PRE- SELECTOR W. E. Skutt, B'klyn, N. Y. (Q) Kindly print a diagram of a 3 -tube pre -selector using two 6D's and a 2A5 as a rectifier. This should be a self -powered amplifier which 2 -tuber using type 76's. may be connected to the input antenna and ground posts of any maximum sensitivity and smooth re- the screen -grid circuit. short -wave receiver. 1 -tube receiver using a 6C5 or generation with the particular coils (A) The combination of a 6F7 (A) A 2 -stage pre-selector of 6F7 metal tube. used. and 76 makes a very excellent re- this type will present a tremendous ceiver. In it. we really have a re- increase in sensitivity. As shown, (A) If you wish to sacrifice the generative pentode detector, with the two tuning condensers are op- filament windings on this trans- AMPLIFIER FOR METAL two stages of resistance- coupled erated separately. If they are former you may use a small step - TUBE 2 audio amplification, all with two ganged, then a trimming condenser down transformer ahead of a 600 Rudie Bartel, Comfort. Texas. tubes. Regeneration. as requested, having a capacity of around 50 volt transformer. However, it would (Q) I would greatly appreciate is controlled by varying the screen - mmf. should be connected across the be more economical to obtain an- it if you would print a diagram of grid voltage. 140 mmf. tuning condenser in the other 250 volt transformer. Any re- a 6K7 T.R.F. amplifier which can first stage. That is the stage im- sistance unit used to reduce the volt- be added to the "Metal Tube 2" mediately following the antenna. age will give very poor regulation. receiver, described in the September HOW TO GET VERIS issue of Short Ware Craft. Ray Ward, Chicago, Ill. 606 6D6 100 - This should use standard 4 -prong (Q) Would you please tell me how I may obtain verification cards from short -wave stations that I receive on my radio? Also, kindly point out the correct procedure in the coming issue of the "Question Box." (A) Many of our readers have expressed the desire to obtain information regarding requests for veils. It is a very simple procedure. Merely make note of the time, date, and character of the program received. together with any other information which you feel may be of interest to the operators of the station, and send this to them ac- 10000) companied by an International Pos- 't L.tg.Nti 110V, tal Reply Coupon. Of course, there 606 606 2525 C. 275onM5 atrD.c Kt. amplifier using a metal are a few stations which do not is- tube. sue verification cards. 2- stage pre -selector operates from either A.C. or D.C.

www.americanradiohistory.com 161 SHORT WAVE CRAFT for JULY, 1936 Amateur Radio Station, W8FRC

Gerald D. Coleman, Johnstown, Pa., owner and operator was

awarded our "Silver Trophy" for his work in Johnstown Flood.

THE "Ham" shack is a room 9 by 12 for final class "C" amplifier-the other ft. in size and located on the second 300 volt supply for the crystal oscillator floor. The radio room is more like a stage. On shelf three we have the speech studio and a transmitting room com- amplifier and class "B" modulation equip- bined-in fact the folks in the neighbor- ment. On this same shelf we have a hood think it is too nice to be called a "beat- oscillator" "SHACK." and its power-supply. The walls, newly papered, are free used in conjunction with the Scott re- of QSL cards and, except for a U.S. ceiver, in order that cw may be copied. and World map and several pictures, are Shelf two holds the crystal oscillator and without adornment. The woodwork is the intermediate amplifier, while shelf painted Ivory. One side of the room is one contains the final R.F. amplifier. taken up by a large studio couch to take The crystal oscillator uses a type 59 care of visitors or the operator, in case in a tri -tet circuit -the buffer is a 46 he tires during the operation of the sta- and the first class "C" amplifier uses two Gerald D. Coleman. tion. type 10's, with an taken while on input of 70 watts mi l'.S.N.R. training The operating position consists of a phone and 100 watts on cw. The antenna duty, at l'hiladel- large flat-top office desk on which is a system is a Zepp type, with 132 foot flat- phia Scott 12 tube Allwave receiver-key and top and 45 foot feeders. Navy Yard. microphone. The switches and controls W8FRC, since its inception, has oper- on the transmitter are accessible from the ated almost entirely on 80 meters, using operating position, without resorting to remote control equipment. cw telegraphy. The frequency used has The Transmitter at The transmitter frame is made of hardwood, now six years old, been 3610 kcs -this frequency is used by W 8 F R C. Larger and the panel is made of prestwood. (Lack of funds has kept members of the U. S. Naval Communica- Triplett meters have W8FRC from being rebuilt on metal.) The rig is six feet high tion Reserve in the Fourth Naval Dis- been added since and twenty -one inches wide. The entire rig is built so that it trict. During the Johnstown Flood of this photo was taken uses the six shelves without crowding. 1936, W8FRC operated phone on 3908 kcs. The bottom shelf or number six contains four large "B" bat- in order to give "news" and expedite the transmission of mes- teries used to bias the tubes. Shelf five holds a 500 volt supply sages to the outside world. It might be well to mention that the for the buffer stage and power supply for speech and modulators. naval reserve frequency was guarded by WBDYY, who lives Number four contains two power supplies -one 750 volt supply two blocks from WBFRC. but

New Electronic Eye Tester and The flit tube changes the fluctuating voice Book Review Tuning Indicator coil current to d.c. so that the 6E5 tube will then show an increase or decrease of PRACTICAL RADIO COMMUNICA- By K. Phelan speaker volume by the expansion or con- TION, traction of the moving shadow portion of by Arthur R. Nilson and J. L. SHORT WAVE fans and experimenters the "eye." Hornung. Size 61/4" by 9 ", 754 pages, will welcome this new Test -All Device. over 400 illustrations, This employs the latest 6E5 elec- This device may be used as an output durably bound in new unit meter to measure a.c. and d.c. peak volt- flexible blue cloth with blue edges on tron ray tuning indicator combined in a ages, pages. novel circuit with a 6116 double diode and also to make tests of audio circuits, Published by McGraw -Hill Book filter circuits, power packs and a.v.c. cir- Co., New York; price $5.00. a 6C5 super triode. cuits. It is invaluable for lining up indi- The new Cisin device has a self-contained It almost seems like equally well on vidual r.f. and i.f. stages; also for cali- a platitude to say power supply and operates brating signal generators and measuring that this fine new book on radio com- a.c. or d.c. When powered from an a.c. munication, which is accomplished by signal generator output. inciludes short -wave source, rectification This article has been prepared from data and ultra -short wave sections, should be means of the 6C5 tube. The 6H6 tube also on every radio student's rectifier, but in this circuit supplied by courtesy of Allied Engineering bookshelf -but functions as a Institute. the reviewer, who has been constantly on serves to convert incoming (input) a.c. to the lookout for a direct current, so that a d.c. voltage will be really good, complete indicator book on radio, feels that no real student applied to the grid of the 6E5 of the subject can afford to be without tube. this work. While designed to help the primarily The authors, both of whom have had a short wave listener to tune in more distant broad radio experience professionally, stations with his present equipment, the have covered in new device is undoubtedly one of the most the subject a most excel- ever devised for general lent manner. The opening chapter deals versatile devices with direct current electricity and mag- radio test work. netism. The The "Test -All" can be used to supply a treatment is surprisingly of the antenna complete and new angles such as mag- quick and effective test netostriction, etc., are discussed. The sec- system, indicating leakage or the presence ond chapter deals with of grounds. alternating cur - to assemble and wire the cents in a refreshing manner and every- It is very easy thing is so well explained that the stu- new tester. The entire device is mounted dent can understand in a small metal cabinet as shown in the the text very easily 6C5 and the 6H6 with the help of the excellent diagrams. illustration, with the The section dealing with the vacuum tubes on top, and the 6E5 tube at the front. tube is An aluminum shield is placed over the 6E5 exceptionally well handled and to protect the color screen from light pene- just what happens in the various forms tration. The sensitivity control potentio- of oscillatory circuits, including trans- and the three pin jacks are also 6E5 /1MEG mitting circuits, are discussed and illus- meter trated thoroughly. Later chapters deal mounted on the front of the cabinet. The with "on -off" switch is combined with the poten- LW/1*M antennas and wave propagation and tiometer. The filaments of all three tubes cover all of the well -known as well as the in series being in series "C%O, latest types of antennas. are connected -also Other subjects covered are: Broadcast with a 310 ohm resistor contained in the studio acoustics, transcription apparatus, line cord. The new testing instrument control -room operates on A.C. or D.C. and the nega- ww% 6r5) equipment and operation, tive leg of the tip -jack (black) is always broadcast transmitters -with diagrams, 0.5- communication transmitters, commercial "hot" with respect to incoming voltages. 25 MEG. When the "eye" glows green, the negative MF e receivers, radio aids to navigation, recti- .tNA33.S ONLY fier units, dynamo- electric machinery and (black) pin jack is on the grounded side (USE NO EXTERNAL ONO) of the device. To use the instrument as a meters -including motor -generators and indicator, the leads from 14. . 3i0ONM31 control apparatus. The final chapter is a tuning attach 11óv.. very terminals (1) and (3) to the voice coil of SW. (ON O.SWEG PO ) complete one on storage batteries. the speaker and also connect the (1) ter - A very useful appendix is found at the minal to chassis ground at the same time. Appearance and hook -up of Tester end of the volume.

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 165 J RX-14 BS-5 6 -tube Band - 5 -Tube Band spread Receiver Receiver 13Sí to 600 meters switch OUR LARGEST. 91/2 to 600 meters FINEST, AND MOST A powerful, sensi- SENSITIVE SHORT tive, and selective WAVE RECEIVER SW receiver cover- which WILL satisfy ing the entire wave- even the most dis- length span of 9 t,(, criminating SW fan. to 600 meters in 5 Uses two 6D6, two 76. one 42, and one 6Y3 hi -gain tubes as TUNED steps. NO PLUG -IN COILS are used. Simply turn the waveband RF amplifier, TUNED electron coupled screen grid regenerative de- selector switch and enjoy reception on any wavelength within this tector, POWERFUL 3 stage audio amplifier, HUM -FREE full wasp range. rectifier and built -in power supply. Operates from your AC bons, Uses two 6D6, one 76. one 43, and one 25Z5 tubes as RF ampli- current. fier, electron coupled screen grid regenerative detector, powerful 2 POWERFUL hi-quality audio system eklleering 3 watts of power to the built -in stage audio amplifier with pentode output stage, rectifier, and corn - hi- fidelity dynamic loudspeaker- automatic headphone lark- smooth regenera!i ii and volume controls-connections for doublet or single wire antenna -black shekel plete built -in power supply. finished metal chassis and cabinet of extreme beauty- selectivity, sensitivity. and HUM-FREE-Hi-fidelity dynamic loudspeaker -illuminated, air- volume that will amaze you. PRICK. complete with 6 tubes, 8 coils.$n95 plane type vernier dial -band spread tuning control-automatic cabinet, speaker, wired, less B.(.. coils, ready to use...... _ ...... - ...... -.. -... headphone jack- extremely smooth acting controls -operates from (2 ltl'oadrast (rand coils, extra $1.45 your AC or DC house current -beautiful, heavy, black shrivel finish chassis and cabinet. RX -14 KIT$1495 AMATEURS: DELIVERS GREAT LOUDSPEAKER VOLUME ON THE GREAT of Imereisaty parts, In- If METAL OF SHORT WAVE FOREIGN STATIONS UNDER owe Model RX14 -An MAJORITY eluding K loo -loss coils TUBES are COMMUNICATIONS FAIR CONDITIONS. for 81k to 200 meters, BF:CHITS:II has and simple instructions. (less the e glassass sir specifications PRICE, complete with 5 tubes, cabinet, speaker, wired. cabinet, tubes. and BC coils. Un- tape. add SI Mt ÁX -14 pt ready to use a lred/ $14.95 to prlre. It is equipped $1695 Beautiful. heavy steel cabinet. ex- with special coils fr We 20- 40 -Nn. tra 12.50 IRO M hands which BS -5 KIT. of necessary parts. Includ AMATEURS 6 MATCHED .tlu7TUBPH spread these hands lug speaker and detailed instructions, Model BS -5 -AB h...., mu, tubes 12.95 less tubes, cabinet. unwired SPECIAL Don of the tuning Beautiful, black shrivel finish metal cab- eleCiñcatlons as BS -5 RX -14B: dial. Also e.tullted xeeptthatit has special Complete kit, cabinet, tubes, Battery mo- with plate inet, extra $2.00 5 ELI) Areturus tubes. extra 2.50 bandspread elrcult for speaker. and detailed instructions, del of RX- cut-off itch fur Net of AIAT(II leas B.C. coils. un- Subtract use luring trans 20.40- lO.I00 M [ands $19.95 14. Complete kit. cabinet, fret $1 fron above mitting periods. An SPECIAL: $14.95 and is equipped with - Ideal receiver for tubes and 11151 rixt louts, unwired. Labor for airing and test ee 11 o s a ut W amateur Labor for wiring and testing. extra. $2.00 plate voltage -of ing. extra 2.00 bat series 1. Broadcast (rand coils 12), cations work rmn '.I -I Of metal tubes arec 'referred to glass type, switch. Add $1.00 to extra 1.4' $1 to cries of ItX -1 1. above price.

HF -35 3 -Tube SW 13A3 -Tube Transmitter SW Receiver .t powerful and well engine.r- 6C a r 9 e to 600 meters rd nateur band transmlle 4 great beauty and cinch ury SHORT -AT A PRICE WITHIN WAVE Icshand THE AMATEUR'S REACH. Amcient !'sea 53 -46 -iii tubes as TRI 4 -TUBE model. inexpensive In TET CRYSTAL CONTROL- Recelrer e tint a wiz- LED OSCILLATOR -CLASS i C RF POWER AMPLIFIER A Cion! in ir .lee three -buitl -in antenna tuning Perform- tubes in a spe- .oleo -beautiful, black shrir- ancs cial .I metal ease and alien-nit:- tive xener - of audio amplification and Triplett meters -Ellen trans FUI.1. 0 TURF. PERFORMANCE.- POWERFUL 3 STAGE. tive circuit with one stage AUDIO AM '1. :FIEIt which takes the guesswork out of complete power fitting dials -highest qual so-called Is,eaker reception" ernir l MlMal r for easy toning.ig ity construction -35 watts of nfl-OOF1 (twin 2 in 1.- 76 -12A7 (twin 2 In Goal volume on all stations. power output on 20 -40- 80.160 11 Chi-sá lia audlitor'amplifierregen- Small. compact. and light in weight. erative rloe.r POWERFUoLli sage audio nfrom AC or DC house current. M bands. A transmitter that deft Operates cabinet. !with penba e output stage. L tinier anti ! um Back. crackle finish metal chassis, pan, you can be proud to own. Ary free Power supply. Completely lf- contained. Noth- welkin( miter Uldl. for 11l'/'ß ing required. Operates entirely from 105 to 130 Po, el to be added Lib -r. dis or 9DC Eilen 3A KIT. of necessary parts. stages light 'ket. 1 1 an I 'u l i - Ins roils for !1 s pm 2 la meters. nd sroils for any simple instructions. less cabinet,rotules. IrufIlnua Included. RAND SPREAD TUNING -smooth regeneration Con - a.t'. ends, unwired. trol- bmrill -in igh quality loudspeaker -automatic `leatti ful, crackle finish cabinet, extra H F -35. assembled. and to seire (less headphone ja k- large illuminated airplane type $1.14 ronly er r dial-large low -loss inductances Set of M.tTC111 :11 biset, rinser supply, crystal. holder and i3 winding tombes. $2195 -selectivity, tivity, and volume that will SPECIAL: Complete kit.et.aulnrt a.Ilii bxbal colis) ze you M y metal chassis less B.C. Cous, unwired black shrivel finish and instructions, S I.dched Arcturus Thies CSI $2.15 cabinet. Must be seen to be appreciated. Sat- extra $1,55 isfiedd owners report dozens of foreign stations on litote for wiring and testing. E i lcn quart,. crystal I$0 or 15111 tl.n'. 2 band coils, extra loudspeaker -You may do the same under the Broadcast I -:i Isla crystal bolder 1.00 proper conditi n . ORDER YOURS TODAY! YOU'LL !'oils for addit imual bauds. per sel 1.15 NEVER REGRET IT!

MODEL 31I 3TUE BATgEgRRY OPERATED RECEIVER AN IDEAL SUMMER PORTABLE NV4rS 1 -Tube power M -1S Modulator AMATEURS: except that it -le GC KIT funwiredi. of all Sameis l.elllrations 't model :sa supply for c with for a with 11F -:IS 1 Model CA l ary 1mrt'. 4 rods the 2 volt Imattery operated tubes to ' -:15, less wles12.95 minable of m,dulating a s :l of and same foroeces L _ to I care""' $ highly elllrlent circuit a regenerative detector entir e output at specifications and Instrrbrüonn dosas 745 The cabinet of this model Laí'mor fo lln 2 stage audio:.simulator. strati wring extra ed RC pt cabinet. tube.. speaker. is equipped with special leather carrying Tless tubes° that It `Ilas hind II.C. .orlsa t.mxbf`n,c i as a portable. Sanie 83 tube for IIV- c x hree stmlecial enabling the unit Arcturus Lulea tun - Beautiful cabinet $1.2 a 3A- tr :m 05 cents 50- 53 -53, extra $1.U5 circuit rite iong roils for 4 matched Arcturus lutes L Special loudspeaker 1.1 da.. (rJA-xn` .Igo HF -19 One-Tube Broadcast band coils (21 1.25 1nm1 N111,:,nds 7 Transceiver user scale-- SPECIAL: Complete kit. r billet. 5 to 10 meters 4 tees Inudspaker. rad (12.45 HF -4 4 -Tube lae B.C. toll, our rein. ñor illAiled v hlelnnfor the eeóÑ °. bor n to 15 experimenter who is i for wiring and test - 2; _ interested Add .SI to ing. axer, inblan transa mVer $1.50 Meter ins pe'iiilveh price of n('. Combination EILEN SS or GE -AS balMry model of (IA using ; 4 -III- ReceirerTrant- 'lim -:f3 [des. Subtract $1 frone prl.c of 6C'. o i(' -AII. miller An ultra-high lÙwll, u,al. it. HF -3 riueuy Itwin " InI tube, spe- ver de- cial circuit producing great Three - V01111110 and signal streiìi:tl giveL dry cells d Tube Portable loudspeaker volume on sablon operating on . ú"to 13G o'rnnits ÌIM1te I f.an 1 2 to Transceiver ifbol ene xÓ tiller : ultra', rcdiod super NF19 TRANSCEIVER NIT, of necessary Parts, ier.. detector. powerful` . audio fipiobn tr.r recti- and simple instructions less cabinet, tube, 5 and 10 meters fier. and bill[ in power supply . (read volcans o amateurs, police stations. iii-frequency broadcast. teC1 Beautiful crackle finish cabinet, extra..51.25 The ideal battery sluill and 10 operated transceiver nexperimentalá ave dial Issa aver.plated -bw Wired 1 l the expo cater inductances-headphone jack-chromium plated chassis and [tested. extra -n0 for cal Microphone for above. extra 1.:.5 Whit is satisfied only and black shrivel finish cabinet. Extremely EIN I .mall and light in weight. Only lu'x:xdka ". oper- WITH Tln: :sf ates frunn AC house current. ..f aplaraltms. ipowiredstransmitter1,I used FREE lark of SP.,. dotes fie having a range to 10 or as low powered illustrated 20 page catalogue et short re- of permit Os to de- 5 miles. confer and accessories. a NF-4, complete with 4 tubes, cabinet transmitters. Send stamp scribe this trans. use..... $14.45 to coverekits, postage and handling charges. ceiver fully. !'lease MIT. if call parts incloiling leaker, cabinet 4 tubes r'1 t." and instructions, unwired 512.95. 4 hour service. 20% deposit on C.O.D. orders liteaturedts 10!4-xBey-x7qï EILEN B:1BO LABOBATOBF.S, Dept. SC 7, 136 LIBERTY STREET, NEW YORK, N. Y.

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www.americanradiohistory.com 166 SHORT WAVE CRAFT for JULY, 1936 plug in the oscillator jack, tune the transmitter dial for minimum plate current in- ROYAL PR -SIX dication SIX -TUBE RECEIVER on the milliammeter. The oscillator current should be between 40 and Complete srlth all acre sori s Including Stilt- 50 ma. With i gamer supply. speaker. six 1111 all ,'r1, the milliammeter plug in the !I'1í to 015 meters. S45 cabinet; laboratory t, tr, I modulator jack and no speech awl tested. - applied to the microphone, a reading of 35 to 40 nia. May be purchased on our Easy should be indicated. S 40 With speech the mil- Time Payment Plan for liammeter should kick up to about 60 to O DOWN 70 milliamperes, never more, or distortion will result. For mobile work a quarter -wave rod will rr suffice for an antenna. Attach the feeder "NOISE SILENCER to one feed -through insulator and ground See page 78 of June S.W.C. for complete the other to the cabinet. For fixed station amazing description of this device that really eliminates man -made Static, in ar- in the shack, a matched impedance, two - ticle by W. Green. wire feed antenna is recommended. This Complete Kit of every Ire,, re part. all first grade. en'vl:J al,J chassis liui.hr,i t:Jrinrt Duplex Transmitter and nilh all holes `grilled. and rnugdel' ineirmh ions. lees tubas, Receiver is very min Ire.' well adapted to mobile police work, with 'l'Ir re, Silt allia all $3.85 -nwral tuh. $2.50 the proper unity coupled oscillator rpl, I. ufir ,. .:Ç 1.. attach tank amt Olalate, stilh Tubes. _... $8.55 coil. The receiver operates very efficiently on the ultra high frequency police bands. 1936 FULTONE V 3 -Tube Receiver There is no end to the possibilities of the portable station. It can be used on racing FIVE-IN-THREE-6D6-6F7-1 2A7 yachts to report the progress of the races, REAL BANDSPREAD- BUILT -IN SPEAKER may be installed in motor -boats for relay work, or may be used in an airplane or at - SPECIAL COMBINATION OFFER - - the airport to cover glider meets. This Complete Fultone V 3 -Tube Kit, "Eagle Minuteman Duplex Transmitter and Wired, with 3 tubes, f, coils I t', h.. r,on Met ers1. 51245 Receiver" would also make an excellent Loud Speaker and Cabinet ._ _... ._.. emergency station. Wired and Tested add $1.50 The unit was tried out in the author's COMPLETE home "shack" in the Bronx and exception- FULTONE V ally good results were obtained. Of course, THREE TUBE local reports were all QSA5 R -9 plus, with RECEIVER KIT of all necessary parts including large good modulation and frequency stability. airplane dial, crystal finished metal chassis and panel One particular QSO was held with W2AMJ with all holes, four coils 9% to 200 meat Bergenfield, N. J., working ters, and complete easily followed wiring duplex and and tuning instructions a report of QSA5 R -8 through some very (Not wired, less tubes, cabinet, loud heavy QRM was given to our signals. This speaker and broadcast coils) "rig" sure goes places and in fine style. Three matched guaranteed tubes $2.20 I rata on various antennas may be found Metal Cabinet for above 1.25 in back issues of Short Wage Craft. Loudspeaker to fit in set._ 1.45 This article has been prepared 200 to from data 625 meter Broadcast and Long Wave Coils, supplied by courtesy of Eagle Radio Co. T svo Coil, . $1.25 Parts List for Transmitter 12 WEST BROADWAY 1 -Unity coupled oscillator tank coil (Eagle) HARRISON 1 -15 mmf. variable midget condenser (Ham - , 8 a, NEW YORK Dept.0 -7 N. Y. marlund ) 2 -.002 mf. mica cond. 1 --5mf. 25 volt electrolytic cond. 1- 500,000 ohm potentiometer with switch What's New in Short- 1 -5000 ohm 10 watt 1 -500 ohm 10 watt Wave Apparatus 1 -1000 ohm 1 watt (Continued front 3- single- circuit closed jacks page 150) 1- Thordarson fiA6 class "B" driver audio "13" modulator delivers ample audio power transformer Ni,. 6747 sufficiently modulate a 10 watt carrier, 1- Thortlars "n fA6 class "B" R.F. load out- pith a high percentage of modulation. The put No. 6759 modulation system is designed to work 2 --7 prong isolantite sockets from a 200 ohm single button carbon micro- 1 -7 prong wafer socket 1 -s. P, S. T. toggle sw. phone. A plug -in arrangement - is pro 1 -Tank condenser panel vided for a power supply cable, facilitating 1- Bakelite shaft hanging front mobile to fixed station 1 -Shaft coupling .,peration. All parts are of high quality 2 -Bud 2 S inch silvered dials .Ind insure a long period of use and maxi- 3- Silvered indicator plates mum efficiency and performance. 1- Triplett 0 -150 D.C. milliammeter For a permanent or separate au- 1 -Meter plug The oscillator unity -coupled tank coil I -Meter cable tomobile speaker the Model 870 VS 6 wired directly on the isolantite 6E6 tube 4 -Bar knobs inch or 930 VS 8 inch NOKOIL Re- socket plate prongs, for shortest leads 2- Feed -through insulators possible. A Peewee battery clips producer housed in our attractive ve- bakelite extension shaft runs 2- out to the front panel on which a nickeled 1 -Mike battery connector 1 -Power cable hicle cabinet, as shown above, is posi- Bud dial is mounted, minimizing hand - 1 -Eagle Black crackled cabinet 17x9x8 tively unbeatable. capacity effects when tuning. All wiring is 2 -Eagle Duplex transmitter chassis. done on the bottom of the chassis and R.I.% (For "Receiver" parts list, refer to page A demonstration leads kept as short as possible. 751, April issue.) Two feed -through ,,ìeans a sale insulators are Write for further particulars, com- mounted on the cabi- 0.5- 6F6 oR plete catalog and name of your near- net to bring the an- 10-20 MEG. 6 C5, 42oa RES. IN est distributor. tenna 76 OR (.2A5 feeders or SERIES) transmission to the MEG.)1 WRIGHT -DECOSTER, Inc. plate tank through 35 2257 University Ave. St. Paul, Minnesota two mica condensers. MMF. ç36 Export Dept.: M. Simons & Son Co.. New York An aluminum shield O Cable Address: "Simontrice." Canadian (Mice: O g Decoster, Inc., Guelph, Ontario !rtween the trans - -hitter and receiver r.lfectively eliminates e VEST POCKET :iny interaction be- 7 / SOLDERING IRON t ,Steen the units. Tun- s ngthe transmitter is 251 MMF. 50 0.5- Smallest good iron now on m pl ici ty itself. With MMF. the MF. market. Will do the t h e milliammeter work of Irons twice its .006- am/ sire. (huy II Inches lone SW. 4 Inch to diameter. Ity inc the highest grade wiitú 50.000 elements. It heats up in half the time of ordinary irons. OHMS Guaranteed to give satisfaction or money back. Sent Prepaid for $1.06 5 Meter Super - R.F.C. 50,000 1,000 GOLD Regenerative SHIELD PRODUCTS CO.. OHMS OHMS 17 West 60th St., N. Y. City Receiver B +,250V.. 1

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www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 167 The New Hammarlund "Super Pro (Confiunnl Pram poll,' 153) unit. For instance, in the "Super Pro" this intermediate amplifier consists of 10 tuned circuits in cascade, certainly an im- practical number to control with variable tuning. The mechanical or structural separation of these two parts has, therefore. been carried out almost as completely as their electrical or functional separation. The "Super Pro" tuning unit consists

AGAIN HAMMARLUND presents tuning capacitors. Placing the crystal a masterful engineering triumph between the two windings secures max- -the HAMMARLUND "SUPER -PRO" imum crystal efficiency. CRYSTAL FILTER! Its outstanding fea- An accurately ground Isolantite hold- tures- features that have never appear- er provides a precise and uniform air - ed heretofore in any such unit set a gap. Carefully lapped holder plates new standard in crystal filter design. insure absolute flatness. The wiping - The selectivity control is noteworthy. motion switch is trouble -free and absolutely noiseless. Thus dependable and Input with Faraday shield. This control varies selectivity from the unit knife -like point desired for C.W. to the effective results are positively guaran- wider degree of selectivity required for teed! of the band -changing switch, main tuning practical phone reception. This crystal unit is but one of the condensers, bandspread condensers, tuning Another original feature is the crys- many, many features of the HAMMAR- coils, tuning dials, dial masks, and dial tal transformer with its two impedance LUND "SUPER -PRO" RECEIVER. lamps. It is a completely enclosed rigid matching windings and air -dielectric Send today for the complete "SUPER - unit, and fits into a large rectangular cut- PRO" story. out in the center of the receiver chassis. Only eight leads project through rubber grommets in the sides of this unit and connect to the receiver proper. Mail Coupon for The "Band- Change" Switch And now, for the description of the unusual band changing switch. This switch Complete Details! has five sections completely shielded from each other. Each section consists of a two -pole, five -position switch. The basic principle is that of the standard knife - Hammarlund Manufacturing Co., Inc. SW -7 switch which has proven so dependable. 424 -438 W. 33rd St., New York Silver -plated knives, mounted on bakelite Check here for complete data on the new Ham - panels, sliding in guides are raised and marlund "Super- Pro." lowered by cams on the switch shaft. In H Check here for 1936 Hammarlund General the lower position, the knives engage pairs of contacts on the switch base, thereby Catalog. closing the circuit. The base contacts are Name - of spring bronze, silver- plated. Each has Address six separate contact fingers to further insure dependable low- resistance connection. This design eliminates the necessity for pigtails, wiping rotary contacts and even the pivot of the knife blade, which is probably the chief source of trouble in the standard knife -switch. Since the switch HA111111A1!1.11111ÍS %:ir'2" YEA!! knives merely enter and leave the spring base contact, as the circuits are opened and closed, there is absolutely no "passing through" action -with its attendant wear. Consequently there is no chance to build DUBILIER$`, V4 up a conducting path of metallic particles CORNELL- r

111"S Va. I CI Type 86 mica 1 repan tor. hermetically I, sealed in a gland porcelain eon - txiner, is constructed of only the finest India Ruby Mica, the most practical. dependable, - low priced transmitting condenser. Type TD impregnated and filled with DI,- liana in non- corrosive containers. is the acme of perfection in the condenser industry. the smallest, most dependable and economical oil filled transmitting filler condenser.con. T dv rug u, [rho r ,i,bi J. , ' lee -Oc mdrinu anal,nnrf.ne. ''

Close -up of crystal unit. CORNEII-DUBILIERCORP.NEWOYNORK CITY Please mention t;ttln:T li'a'r: (RAFT when writing advertisers

www.americanradiohistory.com 168 SHORT WAVE CRAFT for JULY, 1t)3í1 COMPARE THESE PRICES ! ! ! BUY FROM US AND SAVE MONEY Hudson Four Tube AC -DC Radio Genuine R.C.A. Phonograph Tubes 1/38, 1/76, 1/606. I/6D6 UNITED CRYSTAL Motor ILLUMINATED AIR- Induction Type PLANE 3'hls Is the s ono snooty DIAL. Kilocy- DETECTOR motor used luatthe high- cle calibration. Tunes est total iD' Ph...grant. from 540 to 1750 K.C. ud ono binar ions male (170-555 Meters) com- `dr.L1 b ,' 11.I'..t. V 1,tnr. List plete with 4 tubes, un- l'rir SI 8.52 nnnpirte with wired, less short wave turnable. I lesignt' I fur 111.120 volts. . \.r' and and long wave bands a ca llable for either and witches, phono- 110 cycles (Please ¡w- ph s . oar del e. Ist o itlo 'l'bonnao. l l'oint OS ily which when ordering.) jack $6.95 crystal (/ÿ( rnr 7x 11l'tf records. Ship. t.. 10 Ills. EXTRAS-Short Wave band and switch 2,300- With \rumbs l'oint crystal. add 10e extra No. AO -106 6,500 K.C. (46 -130 Meters) add letter S to above YOUR l'I110E $3.95 models 31.00 Long wave band and switch 150 -375 K.C. ($00 -2.000 Meters) for use abroad only. add Yaxley Band -Changing Switch letter E to above 31.25 SPECIAL OFFER l'honm'rnph .lark.. $1.00 . Excellent for short - DILCO R.C.A. Licensed .=J Nave and all -wave 100% Triple Tested TUBES ' receivers us well as G. E. Power Transformer ONLY for analyzers. tlanufacDne.l try t,.nerat Elam t YOUR CHOICE No, AD-1tt 29C former. I1:- ANY GROUP $ OO Desi nned for .,. 1 BANDSPREAD VARIABLE CONDENSERS s \ _ i . Quan. Type Quan. Type Available with 11 platys. r appnu. songuol, fofr111P. tulle; 750 5,0 . .000.2.5 coq ; Zr, lot4a50current. Ship. 3 - -'4A 13 plates. 1.0003 p,fi 2 _- 12A7 4 33-51 bs. - 17 plates, (.000363 mf) ; 23 Pis,.. No- AD 101, G to 7 tube 3-2A3 4-36 1.0005 nit; 16 plates, i.Oilt t.. ri asfo ur 75 mils 99e 12-°-7 4 -47 rut snort -come bandsprea.l r 6 26 4 A2 No. AD -102, 7 to O tulle $1.49 6-OlA- - to well as for staudar. ! . transformer. 100 mils... W 4-6116 cast rend lung naos ver. i., . 6 12A 4 57.3 No, AD -103, .x to 10 tube - - Quan. Tree piste Ai Ill, 3° dial. Snip. wt.. 2 Ils. $1.96 6-30 20 3 48) transformer. 125 mils. 'V 6- - No. AD116 Vernier Variable t 'ondcusers- ,.. 6 - :11 4 - 33 3 - 61'7 :,n.uar o rt !WS page subject to 7L\ R-46 3 2A7 TERMS- ybrrlm 6- - 64-page catalog and treatise. snot loot - prior sale; please 101'811 your G - 56 1 .- la6 3 - 32 FREE card or letter for our rlüa: treatise and 'k.te remittance by Honey ^_ - ln order. certified 3-4.a4 3- 59 catalog whirl) r ,crains nwch valuable bats and radio k .; C.O.D. 866 RECTIFIERS..._.._.. l'.r sill prnnrs. semi 211'; deposit. _...... 89e Information. There is co oldigst mon nlrol vcd. Abso- o:dance ¡ (oAI.D. 24 hour service on all shipments. lutely free. (took sent br return mall. Complete parts in stock for all diagrams appearing in Sbort-I$'arc craft, Radio Craft, QST, Popular Mechanics, etc.

UNITED RADIO COMPANY UNITED Successors to Radio Trading Company RADIO 58 MARKET STREET Dept. S -7 NEWARK, N. J.

between contacts. Nor is it possible to is made with another set. This avoids and fourth coils in each band are special drag dirt or other foreign matter into the sparking in the sections which handle plate radio frequency transformers and the fifth contact. No moving part carries current current and also prevents open grid cir- is the high frequency or heterodyne os- to cause noise or to provide stray coupling, cuits when the switch is turned. cillator coil. Each coil has a trimming and the and circuit isolation shielding by There are 16 tubes in the receiver. There capacitor mounted on its Isolantite base the sections is remarkably perfect. Silver - for circuit alignment to the high -frequency plated short are two 6D6's in two stages of tune R.F.; -circuiting springs automat- a 6C6 as a high frequency oscillator, end of its range. At the low -frequency end ically short the four spring contacts at all electron- coupled to the first detector; a 6A7 alignment is accomplished by adjusting the times. All five positions are passed through inductance first detector; three 6D6's in three 465 kc. by means of a copper disc on an by one revolution of the switch shaft. The adjusting screw mounted I.F. stages; a 6B7 as a combination fourth in a friction bush- five contact points which are 72° apart are ing, which in turn is mounted in the top very definitely located by an accurate and I.F. and diode second -detector; a 6C6 as a of low- frequency each coil form. positive detent mechanism. No stop is beat- oscillator; a 6B7 for This article has been prepared AVC; a 76 from data used, so that the switch can be continu- as a resistance coupled A.F.; a supplied by courtesy of Ilanlmarlund Mfg. ously rotated in either direction. The tim- 42 as a Class "A" driver; two 42's as Class Co. ing of the cams and arrangements of con- "AB" or "A Prime" push -pull audio output; A second discussion of this interesting tacts is such that the circuit through one a 5Z3 as a plate voltage rectifier; and a receiver u'i!t appear next month. set of knives is not broken until contact 1 -V as a grid voltage rectifier. The tuning coils are mounted on in- New Apparatus for dividual isolantite rr bases, which are in the "HAM turn secured to the uvl front shielded partitions forge 152) of the lower have illustrated the mh., 125 ma. 23 ohm, half of D.C. resistance receiving choke: and t h e tuning also the 1 unit. mh.. 500 ma.. transmitting choke which There are 25 has a coils in D.C. resisbu ce of 2.38 ohms, all; 5 for each of Other chokes of similar construction the 5 bands. having In each the following specifications are band also announced- the input cir- 5 mh.. 125 ma., 34 ohms, cuit consists of two D.C. resistance. 1.5 mh., 500 ma.. 3.13 ohms, D.C. resistance. I coils - antenna or mh.. 500 ma., 5.52 ohms, D.C. resistance. primary coil. and a Two new rf. chokes designer) grid or secondary for diathermy apparatus. presumably for the ultra high fre- coil. These two coils quencies are also introduced. are One of these has effectively All inductance of .15 mh., 500 ma. carrying shielded from each capacity. other and 1.24 ohms, D.C. resistance. An- electrostatic- other has .54 mh. inductance, 500 nia. carrying ally by a Faraday capacity. and 1.84 ohms, D.C. resistance. screen placed be- Here is a complete line of chokes which cover tween them. The everything for the transmitter transfer of energy and receiver. from the antenna to the grid is thus POLICE CALLS, corrected to date, limited to pure will appear in the next issue! electro magnetic Also the "Commercial S -W Receiver" The elaborate, precision -built tuning unit. coupling. The third Hook-tips department. Please mention SHORT WAVE CRArr when writing advertisers

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 169 Details of HAM Sets That Will Flash Yacht MINUTEMAN Race News DUPLEX TRANSMITTER (Continued front page 134) AND RECEIVER 5TUE KIT to shore or from one boat to another. The first time in History a Trans- The power supply is entirely batteries. mitter AND Receiver was ever sold Filaments may be lighted either from a COMPLETE for such little money. 6 -volt "Hot- Shot" or a storage battery, This is NOT A TRANSCEIVER. though the latter is preferable. Power for but TWO COMPLETE UNITS in the plates of the oscillator and the class one cabinet. 5 METERS OR MOBILE OPERATION B comes from five 45- -FIXED modulator a bank of Complete transmit- volt heavy -duty Eveready B batteries. All ter and receiver. CIRCUIT less tubes, unwired.," TRANSMITTER connections are made through the medium 950 USING 3 MATCHED TUBES RECEIVER CIRCUIT of a four -wire cable permanently fastened Includes cabinet__. USING 2 MATCHED TUBES Set of 5 Matched T into the chassis and emerging through a Tubes for Transmit. For the receiver. we are using the ÓS 1,A Untwists \flmaeuma, the Must rubber grommeted hole at the back. ter and Receiver I kit» it Ind n or. n luth Eagle I we delivers ample audioa lamer to Sens it and Selective super-re- Only three tubes are necessary. A single Transmitter a n d sufficiently Pooiuiaie a 10 watt generative receiver known. The 6A6 functions as a pushpull oscillator; receiver. wired and 45O carrier. A 636 with both triodes hits uatsl in the receiver are a tested as a fil li for a super-regenerative de- another 6A6 operates as a class A driver comiected in parallel ,leech RECEIVER MAY BE dmop! iller supplie ,sigh audio tector and a 42 for audio output for a third 6A6 which functions as a class BOUGHT SEPARATELY rive to sui .g the class Is GAO lihich provides sumcimd drive for B modulator. Due to the use of a single - modulator gruel, Positive. loud speaker operation. TRANSMITTER MAY BE button high -output mike, no speech ampli- BOUGHT SEPARATELY is CITY fication necessary. A Beautiful Black Crackled EAGLE RADIO CO., 84 CORTLANDT ST., NEW YORK Extreme care has been used in insulat- Cabinet, (size Gss!.,sa1. Gr:Nrl.yalEN: Phase send items checked helm,. ing the RF portion of the circuits. To this with hinged rover. that sells wired. tulbn.'mi. includes tantinet $19.50 regularly for $3.90 is /11- less or Mon. end, all RF wiring is mounted on a small ridded FREE in our $10.50 set of a matched tubes for transmitter I enclose Check Victron panel set into the metal subbase. cmu,lnat km offer. end r mirer $3.95 ey Order for full amount Complete transmitter. less tubes. rabi et or 2Ur'r with order. 3x5x1/e inches Sold se This panel measures thick. EAGLE CIRCUITS aY C.O.D. (Freight by extra.onwitm $14.95 Balance A hole smaller than these dimensions FREE on request ri Eagle Munutentan receiver. less tunes. or postage male./ 14 inch all around was cut through the cabinet. nn red. soul separately (o b. me latest transmitting and re- mets extra, n $4.75 subbase and the Victron fastened over the ceiving diagrams. Send name .almater wired and wired and s3.2s teereedver ss.2s hole. The oscillator tube socket is mounted and address to beneath a hole drilled in the Victron, both 51111 T16._ to below deck get the wiring and to bring EAGLE RADIO CO. STREET AND NO the top of the tube low enough to permit 84 Cortlandt Street the lid of the box to he closed. The unity - New York City CITY STATE coupled inductance, wound of 3 -16 inch J copper tubing, also is mounted on the Vic - tron. only necessary to attach the four -wire The grid coil of especially well- insulated cable to the A and B supply, plug in the flexible wire is threaded through the in- mike, flip a switch and talk. The high - side of the copper tubing plate coil and frequency buzzer for ICW may be left comes out through a drilled hole at the "jacked" in all the time. electrical center. Under normal operation the rig will be Ideal for All Conditions The mike transformer and the Class B run with about 20 watts input. e input and output transformers are sym- The antenna system was laid out with Velocity á l Amp°tite metrically arranged at the back of the sub- the particular object in view of giving good e e pokup Osout b °- base. The mike transformer is No. CS5, radiation and at the same time providing of Picku should not interfere an910 emotion. the input is No. CS29 and the output No. an arrangement that quenc; d1sca mü;c:;. when CS33. in any way with the sailing equipment of 0a tal- ePertttita tilted anal pia Aside from the necessity of keeping all the yacht. Hence, the antenna has been loweredand wiring leads as short as possible, there is made a half -wave di -pole with a quarter as melsitio which no particular trick to wiring the rig. Use wave matching stub, commonly known ndiagál un- row an91e aale the very best grade of well -insulated flexi- a "J" antenna. The base of the matching asad lo elimt cap be ble wire except for the R.F. where No. 14 stub is fed through Lynch Giant Killer in P.A heavily tinned is better, and see that all cable, which may be any necessary length desirabl08 F edback e Elitninal joints are properly soldered with an iron without introducing appreciable losses. work dance mode that is really hot. It is best practice to With this arrangement the whole radiating grid. wire the filaments first, then the grids and system together with the stub and feeders e d reell, in may be in a perfectly straight vertical oolkJ lastly the plates. yaooth -ac tionstanda5 Reference to the wiring diagram will re- line occupying the minimum of space and Podtive. veal a little unorthodox practice in that a out of the way of everything. Write tar PA -2 double- button mike transformer is used. All of the engineering work on the trans- Bulletins J' One side of the winding is used for the mitter, as well as the complete job of single- button mike and the other side for wiring was done by Edwin Ruth (W2GYL) Dycr.. Ito.., ..rt. st the high -frequency buzzer. This simplifies head of the Technical Committee of the construction. Garden City Radio Club. Working with The resistors, all of which are 10-watt him, Harry Lawson (W2IER) helped in noninductively wire wound Aerovox, are planning the layout and did all of the me- _"41.110, AMPER/TECr chanical work. larger in wattage capacity than really nec- 561 BROADWAY MEW YOaX essary. The sockets are National Isolan- Parts List tite, subpanel mounted. The R.F. choke is 2 -.001 mf. fixed Mica Condensers (Aerovox). AMPER/TE -Nelocili MICROPHONE a National type 100. 1 -UMA 15 mmf. variable condenser (Na- In order to put the rig in operation it is tional).

ANT. 0.5 R.F.C. Do You Want the yAEG. (2.SMH. 37 42 3 1 3.1 95 LATEST RADIO DATA? /_ OUT- PUT 15 lf's yours for only 4 cents per month ... lust ppMMF. p po C) G a she mailing and mechanical costs when b ww\ you subscribe to the AEROVOX RESEARCH " C Cl (e7 WORKER. Only 50e per year. A reel en- 50,000 amt, gineering data service. 0.35 X X OHMS MMF. X DOG Mg on request, together with (taOUKnO FREE COPY latest catalog of the corn - Mom) .25- 1 -- -2000 10 -s plete line of condensers and resistors. MF. MF. OHMS MF. T ) \ 50 000 (500 -II----4I- OHMS OHMS C C, .X 75,000 11+ 5 C 100 X X C1..001- s 3v. 250V.0 MMF. MME. OHMS -e X MF. er-w. CORPORATION hlook -up of 5 -Meter Super- Regenerative Receiver. Full Details Will Appear in 72 Washington St. . . Brooklyn, N. V. Next Issue Please mention StfaRT WAVE CRAFT whets writing adverr

www.americanradiohistory.com 170 SHORT WAVE CRAFT for JULY, 1936

this information can not be used for your own benefit it is interesting to be "in the know" first. The R.F. spectrum also will hold about five CW stations in the same "COSMAN 4" space required by one phone station. 5 4 TUBE RECEIVER 4. Tubes. The developments that are BAND made each year in tubes are amazing. New * Continuous Band- * Dynamic Speaker circuits which follow may greatly improve spread * A.C. D.C. Operation reception. Such tube circuit developments Two New Metal have included a.v.c., q.a.v.c., a.t.c., noise * * Built -in Power Sup - Tubes suppression, bass boosters and voltage - doublers. 15 -550 Meters PlY * 5. Antennas. Directional and noise re- * No Plug -in Coils * Earphone Jack ducing antennas for receiving make all the All modern improvements have been incor- difference between hearing and not hearing those elusive foreigners. Directional arrays porated in the design of the " Cosman 4." world. Tubes used are: 2 the -6K7 the higher frequency amateur bands Tunes from 15 to 650 meters without a gap. 1 for metal tubes, -25Z5 and 1 -43 power effective. Continuous Bandspread feature permits sep- pentode amplifier. make your signal much more aration or spread of signals on congested 6. Portable ultra -short wave transmitters bands. Full toned Dynamic speaker is ex- t and receivers-which have such useful ap- Complete KR of parts, less 71050 as remote pickups, communica- tremely efficient and delivers surprising tubes, cabinet, unwired plications tion between parties on the move, exploring volume without chattering. Under favorable Wiring and testing extra .._.._...... _.._...$2.511i and are plenty of fun for the conditions the Cosman Four will reach out Kit of Matched Sylvania parties, ham," especially installed in his car or and pull in S.W. signals from all parts of All Metal Crystal Finished Cabinet .12.25 " if boat. 7. Efficient battery- powered "strictly portable" receivers -using two tubes. These TRY-MO RADIO CO., INC., 85-S Cortlandt St, N. Y. C., N. Y. little sets enable the ham or fan to listen in when out of town on business or other POWERTONE ELECTRIC CO., 179-S Greenwich St., N. Y. C., N. Y. reasons. He is able to get code practice or pure enjoyment when he could not possibly have taken his big receiver with him. \Up-\ IíltPROVED (Continued front page 169) 8. Portable transmitters and receivers 3 -6 -prong National Isolantite Sockets. with self- contained power -supplies -for use 1 -0 -150 Milliampere meter. by the ham in times of local emergencies 1 -High frequency Buzzer. such as floods, storms, fires, destruction of 1- National type "B" Dial. land etc. MIDGET CONDENSERS 2 -Open Circuit Jacks. -lines, 9. 5 1 -Type R -100 National Choke. Construction of receivers -using to Note These Improved Features! 1 -1 mf. 600 -volt by -pass condenser (Aerovox1. 6 up -to -date tubes, a.c. operated, t.r.f. or 1 -2 mf. 600 -volt by -pass condenser (Aero- small superhets, equipped with band -spread, New Positive WIO- vox). 1 a to be used for general ham communication ins Contact toi ro- 2 -S. P. S. T. Toggle Switches. tor shah V1 tlh adjust log and for the fans. National type -3 Metal Cabinet with sup- screw. eliminates me- 1- SW 10. Television: In the future the ham chanical noise on high porting shelf. frequencies. 2- Chromium -plated handles. and the experimenter are going to be re- 5.000-ohm ( Electrad). sponsible for some big improvements in Fitting Bear. 1- five -watt resistor ZCloseInsa hold rotor 1- 1,000 -ohm two -watt resistor (Electrad). television methods and apparatus, and be- calibration and animah- 1 -.5 mfd. by -pass condenser. cause seeing the far -off fellow you are talk- liess of operation. 1 -.25 meghom one -watt grid -leak resistor (I. ing with will be a new thrill. R. C.). LA NT IT E. Soldered brass s 3a Maul and ith ISO Six feet of four -wire shielded cable. plate assemblies, and heavy aluminum end plates Microphone transformer. CSS. ulke a precision built. ruggedly etmstruited tvii 1- Third Prize Winning Letter, by Carl E. 1 -Class B. input transformer. CS29. Joe ser. Swanson 1 -Class B output transformer. CS33. Extends 5;16' beyond oar bearing for (Name of manufacturer of above transformers THE following ten subjects are of most 4aShanganging several units with flexible couplings. furnished upon receipt of stamped envelope.) interest to me: Dual units and multiple space units hi various ca- 1. Short -Wave Future: The very mystery pacities illustrated and described in our new catalog. of short waves themselves keeps me con- Free upon request! stantly interested and alert to progress 40°ó DISCOUNT TO AMATEURS "What Interests Me Most being made in a great scientific field. n 1931 E. 55th St. 2. Television: The possibilities of this BUD RADIO, INC Cleveland, Ohlo in Short Waves field in short waves rank it next to that (Continued from page 131) of communication because its perfection tion of our modern system of "air- travel." will affect us all in our daily life. RESULTS 1Jamand Especially "blind- flying," which makes air 3. Therapeutics: Because none of us are GOOD travel possible even in adverse weather. immune to physical suffering, the use of 8. Police Radio-This interests me be- short waves to relieve pain and distress GOOD INSTRUMENTS cause it has become a necessary part of should command the attention of every one. 4. I building the TRII'LETT manufactures police systems in cities of any size, and it Set Building: still enjoy what an important part short 1, 2, and 3 tube sets and sincerely believe a complete line of elec- shows again waves play in our everyday life. that front these simple circuits will come trical instruments for ra- listening had the sets we may be carrying about in the and gen- 9. "DX" Reception -"DX" dio, electrical a as far as I future. purposes become practically "lost art" eral industrial was concerned, but short waves have re- 5. Short Wave Antennas: This relatively both standard and cus- vived my interest and keep it alive. simple device we use to intercept and re- i l better tom b u t -For 10. "Uncertain Reception" -This interests lease radio energy is most interesting to short wave work, write me very much. The fact that on certain nie as I believe we have not attained all Model 231 for catalogue. days stations will roll in like "locals," and the efficiency that further study and experi- 0 -ISO A.C. Wm Aeturaey 2% on other days can scarcely be heard, will mentation will bring about. always make short waves particularly in- 6. Airplane Navigation: On dark, stormy I to the unseen hand that Triplett Electrical ill LET teresting to me. nights thrill Instrument CS. guides the many pilots to their ports. Short fischten waves are a vital part to successful trans- 287 Harndon Drive ELECTRICAL INSTRUMENTS by Alan Bluffton. Ohio Second Prize Winning Letter, portation. E. Vosburg, Jr. '7. Amateur Radio: As I listen to amateur AROUND THE WORLD MY interest in short waves is centered bands I can't help but realize the possibili- WITH THE MBSO about the following subjects: ties for young men and boys to engage in 1. The construction of modern super- a fine scientific hobby, and I, too, feel the 3 -TURF. TRANSMITTER heterodynes-using 10 to 12 tubes of a urge to become a " ham." Thin modern, flexible. Ins censive. crystal -con. mooedTransmuter Kit 50 muet' Ontu- modern type and incorporating latest cir- 8. Foreign Radio: The short wave pro- IItito, driving pair M 5112's to 50 watts output. sets can not grams from other countries are most in- funeutralisation Is required. coils are available cuit features, because these r Iteration all hands from Intl to IO m tern. be for sensitivity and selectivity and teresting as we learn about our neighbors. The M1150 Kit uses the highest quality tar. beaten h names . National. Hammarlund. general dependability. And who knows but that these "unseen 'ngamo. VaxteY andnd1 other. et pally well-known. about international tie complete kit all component parts. 2. Building and operating low and links" may bring crackle finished chassisa aneCoor drilled, Corm.] I am going peace? thed dal and on of l culé medium- powered transmitters. with tnstruettono, less tries. un $19.90 to become a licensed amateur soon and 9. Weather Forecasting: This new use of wired wish to have a small transmitter which short waves may take some of the guess- and will deliver the goods. work out of weather predictions and as [Write for latest "Ham" Circular up such be a daily service to everyone. List of Parts for Building Transmitters 3. Learning the code. I wish to bring and Receivers. my code speed because the majority of 10. Mineral Explorations: Using short stations use code and it affords an element waves to liberate nature's hidden treasures M 8 H Sporting Goods Co. of secrecy (from the layman). Press re- is a most fascinating subject and its prac- ports can be copied hours before the broad- tical use will be a servant of the mining 512 MARKET ST. PHILADELPHIA_ news, and while industry. X1709 Atlantic Ave. Atlantic City.. cast stations give out the Please mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 171

The RX -14 S -W Receiver For "Fan" or "Hamer MARINE TYPE (Conan u,1 f rom page 1",1) communication Receiver ment of parts, combined with the use of electron -coupling, results in selectivity and 15 to 9000 METERS sensitivity that -is undreamed of by the average fan. The use of plug -in coils, well of efficiency, AUDIO GAIN CONTROL. Can be set to limit known for their high order the background noise to suit receiving condi- low losses and convenience, is to a large tions. extent responsible for the excellent results POWER SUPPLY. Heaters wired in parallel obtainable. A thorough test of this model Sargent Model 12 for operation from 6 volt supply. "B" Supply has demonstrated its capabilities for con- from 110 volt ship's lines or auxiliary B sistent foreign station reception with re- Sargent 5hsdei 12 has been Ise thoroughly Batteries. Toggle switch makes the change. engineered with exhaustive tests at sea under Also supplied for full operation from 110 volts markable regularity. actual operating conditions on both Atlantic is D.C. Both sides of line filtered. can be used For the transmitting amateur who in- and Pacific coasts. The final design is, with- or neutral -40 -80 -160 on lines having positive, negative terested primarily in the 10- 20 out question, the nearest to an ideal receiver ground. For operation ashore, A.C. power meter bands, there is model RX -14 -AB that can be developed for work aboard ship. pack (separate unit) supplies all voltages. which is equipped with a plate voltage cut- TUNING RANGE. Eight wave hands giving CIRCUIT. Tuned R.F. type circuit with re- the continuous tuning from 15 to 9000 meters generative detector. Complete isolation, care- off switch for use during transmitting LC periods and special bandspread coils, en- without skips or dead spots. Highest ful shielding make for high stability and ex- ratio, maximum sensitivity, on 18. 24, 36 and tremely low noise level. abling these bands to be spread over a gen- 600 meter ship bands. erous of the tuning dial. Inci- OTHER CONTROLS. R.F. Cain control. Re- portion MAIN TUNING DIAL. Calibrated in M.C. generation. R.F. Trimmer. Speaker ON-OFF' dentally, these special coils are inter- from 15 to 200 meters, in K.C. from 200 to Switch. Power Switch. 0000 meters. Shaded areas mark short wave changeable with the regular coils furnished BREAK -IN CONNECTIONS. Terminals in the (9 to 600 meters) with the RX -14 and no ship bands. BAND SPREADER. Uses Sargent mechani- rear for connection to break-in relay. With changes whatsoever. is calibrated in M.C. contacts open, R.F. biased to cut -off, detector cal band spreader. This dial own This article has been prepared from data for 18. 24. 36. 48 and 64 meter ship bands. undisturbed. permits monitoring trans- supplied by courtesy of Eilen Radio Lab- VARIABLE ANTENNA COUPLING. Vari- mission and gives break -in without lag. oratories. able in 5 steps to match differing interference conditions. wavelengths. etc. Write for complete description and price.. ANCHOR GAP. Located right at the antenna input to the receiver, this gap protects the We specialize in receivers for D.C. and battery The "Transceptor"-A .et against lightning and heavy static. operation and for long ware coverage. MVO AUDIO JACKS. Jacks located in first New 5 -Meter Portable old .stcund .111io stages. E. M. Sargent Co., 212 9th St., Oakland, Calif. (Continued from page 151) trots when the unit is not actually in use. This cover, opening outward on a pair of position, and as a microphone gain control sturdy hinges, makes a very convenient little in the transmit position. A separate writing compartment, in which a log -book, 100,000 -ohm variable resistor in the plate pencils, watch, and even the necessary an- circuit to tube V -1 functions as a regenera- tenna wire may be carried. A special com- tion control. hpartment on the right side of the case As the front view of the "Transceptor" ouses a "hand- set." When this "Trans- indicates, separate tuning controls are pro- ceptor" is closed up for carrying, it really vided for transmitter and receiver tuning. is closed, and no additional hand -bag for It is therefore possible to adjust the trans- a half -dozen accessories is required! mitter for maximum efficiency on any par- The case is made of black crackle finished ticular frequency and then to cover th. steel, and will withstand all sorts of me- entire band with the separate reeeile chanical abuse. The outfit may be ht ndled control. That this is a huge improvemer.L as an ordinary piece of baggage, and can over ordinary transceiver operation be stowed away in any part of a car with- be readily evident to any person who h., out suffering damage to exposed knobs, had experience with instruments of th, dials, binding posts, etc. It can be sat on latter type. and stood on! The inside view of the set shows the neat Electrically, the set comprises 4 tubes in and simple distribution of the various a tested and thoroughly reliable circuit parts. The hand -set is in its own special ELILEY RF2 CRYSTAL UNIT combination. In the accompanying circuit compartment at the left, with tip jacks diagram, tube V -1, a type 30 functions as provided for quick connection. There are For 20 meters. and multi- a self -quenching super- regenerating detec- no loose cords of any kind hanging from plying to 10 & 5 meters. an- panel to interfere with the tun- tor, operated with a separate receiving the front At all Bliley Dealers, $7.50 tenna. When the 3- position switch SW is ing manipulations. The left section of the thrown to the position marked "R" (re- chassis contains the receiver tube V -1 and BLILEY ELECTRIC CO., ceiving), transformer T -1 operates as a its own tuning system comprising a space - straight audio amplifying transformer, wound coil, and a tiny 10 mmf. variable ERIE, PA. working into tube V -2, also a type 30. This capacitor; beyond the partition, to the tube works into a class B push -pull audio, right, are tubes V -2, V -3 and V -4, and the which comprises transformers T -2 and T -3 heavy copper tubing, comprising the tank * BUILD Y ROWN * and a type 19 tube. The receiver portion coil of the push -pull oscillator. In the of the hand -set connects directly to the schematic diagram the dotted lines indicate secondary of output transformer T -3. insulated wire pulled through the tubing. When the change -over switch on the This insulated coil represents the grid in- :ILL-STAR: front panel is thrown to the "S" or trans - ductor, while the copper tubing is the plate mitting position, the type 19 tube V -4 inductor. Snap clips attached to the tank TRANSMITTER operates as a unity- coupled push -pull R.F. coil are run through fixed condensers to a IFREE CIRCUIT AND PARTS LIST I oscillator. The microphone part of the pair of binding posts on the front panel .4mm1e etth a soldering Iran. stress truer and a hand -set is connected in series with a spe- for eventual connection to any of the usual pair of pliers, can build this transmitter. It can , cial primary on transformer T -1, which types of 5 -meter antenna. The audio units be used on 10. 20, 40. s0 and 100 meters. Bands thus acts as a microphone- coupling trans- and assorted fixed resistors and capacitors changed In a few seconds. Designed by engin- former. Tubes V -2 and V -3 then function are on the under -side of the chassis. The , cers. Built from standard parts, stocked by us. as voice amplifiers, with tube V -3 further various dry cells required for filament, grid - Write for our free catalog operating as a modulator tube. The sec- plate and microphone current supply fit ondary of the transformer T -3 is thrown snugly inside the bottom of the case. in series with the B+ lead to the oscilla- The particular "Transceptor" illustrate1 CA!ERADIO : tor tube V -4, and thus modulates the R.F. is the 2 -volt battery model. Another model, 01 -3 GRANT ST., 30 TWELFTH ST. output of the latter, accomplishing the which is undergoing completion, will use PITTSBURGH, PA. V. WHEELING, W.VA. phenomenon of radio telephony. the identical mechanical layout with the Fstahlished 1919 When the change -over switch is thrown 2 replaced by tubes of 6.3 -volt tubes the order most reliable to the transmitting position, it opens the volt series. This model will be available Mall nsecer.d ura lainon,or CdC n filament to the receiving tube V -1, thus for operation on a 6 -volt storage battery, X L VARIO DENSER In. Mod. N. C.p. 1.2 to 20 MME preventing additional modulation of the as in an automobile, with either batteries Mod. CI. C.p. 20 to 100 1,151 F Mod. Gs. transmitter by incoming signals. Resistors or a dynamotor for plate supply; or for Cap. 100 to 600 MAI F are provided in the filament circuit to com- 110 a.c. service with a specially de- Mod. GM -volt s00to l00oat M F pensate for the slight voltage differences signed power pack that will fit in the space á iñä XI. PUSH POST that occur between the receiving and trans- now occupied by the dry batteries. This (best amine typo madia. re." Mad. N 51.00 es. mitting circuit combinations. will make a marvelous little compact 5- Mod. G 31.500. A 500,000 -ohm potentiometer Non -Corrodine -Nyr Type -1114. Top 2a, es. connected meter station for fixed use in the home or Typo III IAlu,ninuin a.... II.t.Ine m.utened Top, 16.. across the secondary to transformer T -1 for semi -portable use outside. Type \I (SII Aluminum Body( at Weeaeb. operates as a volume control in the receive This outfit has undergone thorough field Por quick yoonogstio.. ..d positive -.t-t al all Um-. X. L. 7, i Belmont Ave.. ..e. USA. Please mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com 172 SHORT WAVE CRAFT for JULY, 1936

tests and has proved to be exceptionally successful in all respects. Its improved mechanical construction and electrical de- CROWE 5 -10 Meter Transmitter Components sign will appeal instantly both to the experienced 5 -meter operator who has wrestled Are Specified by George W. Shuart with ordinary transceivers, and to the beginner who wants to get started on 5- meters with a versatile instrument of low DIALS CABINETS cost. e This article has been prepared from data supplied by courtesy of Wholesale Radio KNOBS CONTROLS Service Co.

DIAL SWITCH ,a PLATES PLATES New Ultra S -W Tuner (Continued from page 139) Your Dealer or Jobber has genuine Crowe parts. this particular receiver, the detector cir- Ask for Bulletin 75 for details. cuit is designed for modulation frequencies in the broadcast band. In other words the CROWE entire instrument as shown is not really a NAME PLATE & MANUFACTURING CO. receiver, 1743 Grace St., Chicago, U. S. A. Cable Address: CRONAME -CHICAGO but a S -W converter. Tests have shown that the receiver will respond to a band width of approximately 4,000 kilocycles and therefore it should be excellent as a television receiver when television becomes a reality TWO -TUBE w VE } RADIO SPRAYER OUTFIT in this country. Only $300 ELECTRICAL - PORTABLE $3250 Complete less {L with Gun, tubes, phones, unwired ready for New Television and A REAL, powerful 2 tube Chart Service net that readily brings In Sound Antenna amateurs. police calls. broad - stations. exlaerimental n,1 fcastoreign stations under fair (Continued from page 139) conditions. THE WORLD AT YOUR DOOR! A DEPENDABLE RECEIVER the tower structure. The wave lengths to Is guaranteed to give RrichESULTS. Operates entirely be used in the new B.B.C. television sys- from tile AC or DC home cur- tem are in rent. operate. the vicinity of 6 to 7 meters. shrivel nxda cabinet ction fur.ubrk The receiving apparatus to be used m.hed.Ìushl Wavelength caiinsrange IO to atol metere. in picking up the television images, employs TWO TUSE BATTERY SET, less tubes, 00 I.l umes. Imtterlcs. unwired $2V a cathode ray tube. A great many "field Kit wire,, extra $0.75. Tunes, each. tests" have been conducted successfully Cannonball donlhle headphones $1 25 already, tending to prove that the televi- EILEN RADIO LABORATORIES sion system, as worked out by the engi- (Beginner's Section) neers, will operate in a very satisfactory 138 LIBERTY STREET. NEW YORK, NEW YORK manner. With these short wavelengths or seeeee,e-t ultra -high frequencies, there is bound to This le the Ideal Outfit for all around spraying work be a wherever Current is available. Sprays everything: Lac- considerable amount of absorption by quers, 011. Cold Water faints. Enamels, Varnish, Insect- steel -frame buildings, and also distortions icides. Disinfectants, Shoe Dyes, etc. The Unit Is of compact. the wave as it passes over sections con- 300105 completely self- contained. taining a great many steel frame struc- 14eTUBE Ideal for spraying Furniture. Radiators, Screens. Ma- FREE chinery, and other maintenance paintings In Hanes, tures. Just what the reception results SBANO TRIAL School.. Clubs, Hospitals, Stores, Factories, and office will he under these conditions remains to 111111114111 OAOIO Buildings. be seen. (5,.7400 NnoJ The Gun furnished with this Unit Is of l'ressure Cup type; requires hut 2 cu. ft. of Air per minute. Has Bleeder type construction which assures uniform pressure at all times without clogging the Air ramage which Is easily cleaned. Furnished with 3 Nozzles which produce Fan, Round, and AUDITORIUM TYPE as tuvraZ Right Angle Spray respectively. Cathode -Ray Tube SPEAKER 15sADAY Complete Unit consist. of Air-cooled Compressor with machined Fan-cooling Pulley. V -Belt Drive; Pressure CEE this bigger, bens, mon. powerful, type Gun with 1 quart Aluminum Paint Cup; 3 TIPS Tester cape selective "concert" tone, 14.tube, 5-ban. Heavy Duty Motor, 110/120 volt, 60 cycle. AC radio. Over 50 ed d features. Secures American. 15 ft. rubber covered 2 Ply Air hose; 8 ft. Cord & I'lug (Continued from page 139) Canadian,), tca,amat.e,eirplan. and ship broadcasts... Filter Tank; Entire Unit mounted on Base with Bal Bearing Casters. for sales or technical reference purposes finest world -wide foreign programs. Foreign reception are the guarantee. Money -back guarantee. Factory-to-you A low priced Power Sprayer; the kind of Machine that brilliancy of the fluorescent screen, you 50%. Write today for FREE 40.page catalog usually sells for $50.00 to $60.00. in candle -power or other similar units, and also the MIDWEST RADIO CORPORATION Price of complete outfit, shipping weight, sharpness and intensity of Dept.14 -T as r -n .f lade L..a rahtp) Cincinnati, 011ie 60 lbs. $32.50W the light spot produced on the screen. Price of outfit complete. less Motor. ship- Note the light sensitive cell contained in `d rd pine weight -35 lbs $25.50 the round metal case circuit, supported by I " .HAM "SPECIALSt Tad Ple Price of Gun only with 3 nozzles. ship- 50 the laboratory stand at the right of the A highly efficient Cede teacher pine weight. 7 lbs. - ...... _.. ... _...._._.... ti photo. The illumination projected tenor heavy . aprepared Price of Compressor only, shipping weight through ed paper baring two 15 lbs -. W$9.50 the glass and the fluorescent screen at r f perforations.7" for the end free -S. W. it of the cathode tube, falls on this .1 won dealers cell. In this manner, it is easy to measure ' lu l t 0,1,-d rinenimmies. i Our Old Customers Know That the specific luminosity produced on the We are the oriel of Our Merchandise Is Sold on a fluorescent screen of the tube. Other I n.trummnt. with u plete r rrd chi. type instrument. TELEPLEX O Strict Money -Back Guarantee cathode ray tube factors which can be -.I leerun, eÌÌ for $11.95 72 Cortls dt St.. Na York City measured All Shipments will be forwarded by Express with this newest measuring ap- Collect if not sufficient postage included paratus, are the degree of vacuum inside with your order. the tube and the magnitude of the cathode R A0105EBSAVE°IPl5O% ray beam. DEAL DIRECT: t'artory irw - ;- .h.m ,.,d.I.to.mlertbm WELLWORTH TRADING CO. r----1F.1. - ee'. An -wave. Paros ewer na usw maW Tura ow on 560 W. Washington Bd. Deos. SW -736. Chicago, II. All HAMS will he interested in W2AMN's rrr0sá' Auto .na .CaE» .,n ."i é.ina. ;au NEW _. article in the August number, describing irai n Catalog h, a .irhl'nntEE. Cetdetadn.., new transmitter using the 6L6 (Beam) a o -I,A I' TRIAL tin nn.i Tubes. All hands with I crystal. The ßp`98 -!'per. aromatic., ?`oo Co.. Extraordinary Bargains! simplest yet'. 8780 GrandRRiver ettroit. Mich. plu en guaranteed S.Govw A0 - Mtre22 srsspark plugs. made In r for U. Govern- ment aviation engines. brand new. suitable for modern high powered autos, motor boats etc. today for y . out of new 16 -para 1.041. crammed full ai tic each. 10 for $1.00 valuable and vital inlonnati r, on Visor Cap- Jmmt the thing to u during the hot - Girl Operators, Attention! r days. 25e c ch. 5 for 51.00 "AERIALS AND I. um inoun Gear Shift 13:1116. In beautiiful trnonintrent Listen "YI,'s" and "XYL's"!! Why not NOW TO USE THEM" with made 25e nickel silver Contain. diagram. and mnlete information for nlimineting noir lofas e background r$iaM send the Editor a good photo of your all A m Ìur - oI -Mile, Sr., ultra violet d.. r n inter carloa sun lap,,. with "Rig" -and don't forget yourself. A hel.neul line the h g ¡ ` Sun $1.95 each ï:" n.: In apartment ti . and Son-Mite.Nlte. Jr..- in type which utilises separate photo of yourself :m:e ëmmn nn "!n"ni:leihú.lawli:: dinar), floor a table lamp for support. $1.49neaeach h will do. t,. S. Anon Compass. siways xl, wee ran ICaril with a "clear" photo of that station! Sent postpaid which direction you are traveling. each for a dime S1.95 $5.00 for hest "YL" photo.- Editor. Arthur H. Lysdl, GOLD SHIELD PRODUCTS CORP. Inc., Dept. S, t27 Felten St., N.Y.C. 17 West 60th Street New York City See page 649 March issue for details.

Please mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 173

New Television Experi- (21/2 To 550 Meters) All -Wave Amateur Ultra 1 and 2 Tube Battery Transceivers beginner the field 5 -Tube Communications Receiver - t F""''hr. LIS true ments by RCA heeitau Ir mmend th.e (Continued front page 133) .1 uelyeóaientI and:taho din _ _ N .. can he used as image appears pointing upward, so that leer coin 15en meter receiver p ú1e 1 .from r.i down on a (I) obe unitnalar. Vu...,a one would have to look the I irons r, top of the cabinet to see the image direct- 9. plu theInes) ne..' ,.;,x image, which tar 1 val. A lane me Ines) I.: -, ly. However, the television . bandsprem A mi. tar. 1r. Longer Ix,,,.., . has a size of 5x7 inches, is reflected on a _ plus on an lite i° bud ant, ab ,.old n,.. metal mirror, which is so arranged that eilli tort and t tin. Cre.ant mriltr e:.nr: :i ' super r e n L small transceiver!. can n... persons sitting in front of the set can grfillr oat Len iw'had. Range of I tube moll í. be anbúl,a°anmilew and clearly see the images. C--) 1 lot mc. n!. the a _. wallah) M depending un torsi.,. for Ihr Ili, It' N'.do.eragad re _-1 , of Ille disetiminat hag amateur. t to 550 melt r. Y. tee .Ile and W b las ü 33 Tubes Used In Receiver linear In P:lielt'nry Is ammnni isliod by the use of slim' hatter, a of 33 tubes, .amie salmi up l0 15 nicters and straight allrali,it PICTORIAL DIAGRAM FURNISHED WITH KIT The receivers employ total t'ilb 5 band atcitrldng to v50 omega. The nownew all meta all of which are of the standard receiving nl,ta are used as follows: 617 -1t.F. alise. 6117 -1te (2TUBE MODEL) (1 TUBE MODEL) type, with the exception of the cathode - generative detector. 76- -sung regenerative detmhr. 'S.\r,- l'o\ve output stage. 2,l A.C.ei).(', . Built -Indy A ray tube and its associated high -voltaire nl te speaker. self- metalned \. auto,.. power supply. '. l': Vin, tla , u 5 695 Na ..,ilc lie.. IT rectifier. There are 3 metal tubes in the .Irae airplane handapread dial, automatic phone lack. 1111.. r.hin T 1...... ,.. t 1 d , , ... set; all the rest are glass. I :, k 1 p.rt. I.+, 'taw. "x1.11. 52.pD A total of 14 controls is to be found li i t i. 51.50 -! 1.45 I .o l la 1 .58 Wired and tested. extra 53.00 1vw on 7 on panel and 7 a ' r, n the set, the front - ..I, e kit 1 5 « 4.50 1.10 Itle..k wrinklee finished ' 2.50 1.10 cabinet. This r I i under the movable top of the aet complete s b 1,Ír K 'n.l. nuÍr operate 23.10 top is raised and lowered exactly as is the II ;,real :. 1e Pig l J" e m r, 1 ii) kit II 1.95 Ì, 1.95 top of a radio -phonograph cabinet. Instead of a phonograph turn -table within, how- WRITE IN FOR FREE DESCRIPTIVE ULTRA HIGH FREQUENCY LITERATURE ever there is the cathode -ray tube and the 140 LIBERTY STREET ULTRA HIGH FREQUENCY PRODUCTS COMPANY NEW YORK, N. Y. 7 controls mentioned above. The reflecting mirror is mounted on the inside of thl+ movable top which is left in the raised WORLD WIDE position when "viewing" a broadcast. The 7 front panel controls are for tun- L. WAVE... ing, sound volume, high -frequency and low - NO DOWN PAYMENT frequency tone control; picture contrast, ONE TUBE detail, and brightness. The 7 upper -deck N O W! All Standard receivers and KIT controls are for adjusting the synchronism MARINE Transmitters available on the ONLY $4.25 of the picture, the focus, the horizontal new MARINE RADIO BUDGET PLAN . . POST size and horizontal and I I .it mi. I Tito d1- PAID and vertical the At standard AMATEUR NET PRICES, plus ñ;iwantedw "n. vertical "framing." small carrying charge. Write for full details. , imYerrni r' ;n; ;nt r e i ;i i., vÌLot e .d,i.I Y°`ii nen. Receiver Circuit ASSURED wnr i+ polo, i I, PROMPT DELIVERY .. 'Gt»r i1rIJ \"'.':iFÌlnl. give and the '.IIY\'IEFp itrÍll"!' :i.m:r!. 7'I,,,.114. now The input from the aerial first on following models awn Ani nrrfnr coÍ detector -oscillator stage is common for MARINE VIM. the II . ACE't , n "Ei Mired R.C.A. MODEL ACR -175 .nrïe°,iu.Ì:n F1 no rt r.nÁ y el" both the sight and sound channels. In TRANSMITTERS .;pöw.rtwl ud,e reiÑerr` itini:.nOY tr NATIONAL HRO t': I rl,w 'll! a feeble ,I set! other words, both sight and sound are Write for details , Á °-"Later , wl,n into he Tw.TO* `l.Ì tuned in by the same control. Since there NATIONAL HRO Jr. a n d illustrated .AIINI M° L,1In 'yIl'.` n,lh,e,luetery on M,.fllf.' rl.,aeli ,°I,' woo for .Ái1.ÌÌ PATTERSON PR -16 literature the \\ : t is only one signal -frequency oscillator, and Iort . ,. timid,- :: n..,,.n,,. e,rl.:o inner l':'t.. meter.etermeter. line of one R M E -69 complete as this can be oscillating at only Transmit- FOR MORE POWER AND VOLUME SUPER -SKYRIDER MARINE $n frequency (disregarding harmonics) at a ters for the "Ama- 48 ULTRA- SKYRIDER BUY THE TWO TUBE KIT . . !.;.'Mf'°: time, the 46 mc. sight carrier and the teur" ranging in 1k ono two entire- SKY BUDDY power from 20 to mc. sound carrier must produce ALL ELECTRIC ,,,..',;1;'°5;7,.:,.;'57.; ly different beat frequencies when they are SARGENT 10. I2, 20 1000 watts. S.00 I TWO TUBE RECEIVER;;;.;,:::',;;;;.'",'.!,`,..,44,., a °trig^". mixed with this oscillator frequency. This unsnap.i11. is just what happens and the result is that TI . -75e e ..- I Pohl.. l.r,ipl -81.15 there are 2 different beat frequencies MARINE RADIO COMPANY Any LI. l amr:n:n w vet! :.n,l, ,x1- 74-eat. REM t. \1 NEIL ! -w 1', I:rim.t -r! or "I.F: s" in the output of the first de- 62 Lispenard Street, New York, N.Y. da, are fed to entirely separate ORDER NOW! NOT A TOY OR AN ATTACHMENT!! tector. These (F).rrnerl, Y. I.F. amplifiers and thence through separate Richmond hill, 1.) ACE RADIO LABORATORIES second -detectors and audio systems, with 1619 Broadway Dept. C -7 New York City the picture ending up at the cathode -ray at the loud speaker. tube and the sound Write Gs "Headquarters- The block diagram illustrates this arrange- Short IDENTIFY ment The I.F. employed in the pic- THEM- and Get a Better Deal clearly. Wave SELVES ture channel is from 10 -11.5 mc. while that WITH THE for the sound channel is around 8.75 -9 mc. League ORGANIZA- I A surprising thing about the demonstra- TION "CH -RAD" Members "Hams" for 15 years tion was the negligible effect automobile Headquarters for ignition interference had on the pictures. The latest in receivers and transmitters Frequently the interference became strong In order that fellow members of the LEAGUE on easy terms. enough to render the sound channel mo- may be -available mentarily unintelligible, but instead of able to recognize each other when they meet. we hay. blotting out the image the interference designed this button, which is sold only to members Liberal Trades Arranged caused only slight blurring of the images and which will give you a professional appearance. Complete stock of parts and acces- a second. This was not for a fraction of sories at standard prices. serious enough to he distracting to the eye. If you are a member of the LEAGUE, you cannot afford to be without this insignia of CHICAGO RADIO APPARATUS your membership. It is sold only to those W9RA- COMPANY, Inc. -W9PST Future Developments belonging to the LEAGUE and when you see 415 S. Dearborn St. Chicago, III. This demonstration was given as pre- it on another. you can be certain that he is a liminary to the first experimental field member. See page 190. tests of the system to be conducted in New June 29th. Lapel Button, made in bronze, gold York City beginning about 35c Transmission will be from the new 10 kw. filled, not plated, prepaid AMERICAN'S ultra -short wave television transmitter now AG Crystal Microphone being completed on the 85th floor of the Lapel Button, like one described above $ but in solid gold, prepaid S 2' 00 is being used with 'Ythusiasm by Empire State Building. The studios will be Amateurs and Public Address in Radio City. men throughout the world. Noted About 50 of these experimental receivers for excellent quality and the will be placed in the homes of RCA en- versatility of its mountings. gineers in and around New York for the Complete h.el0ä. to meet every List Price $22.50 QUALITY drilling end en - Licensed under patents of purpose of discovering whether the system insulgowns nel.. and an The Brush Development Co. is practical outside the laboratory. If the PARTS FOR a` i.ls and tal, write today Free Descriptive field tests turn out successfully it is hoped HAMS for complete de. Catalogue! t.l°. 1 CRYSTAL, CONDENSER, CAR- to eventually inaugurate a regular tele- SERVICEMEN .m ird manufacture. Seed 10.. BON, AND DYNAMIC vision system for the public as an adjunct coat RADIO INDUSTRY of Wodl,na and ,n.a,ng.corer Microphones, Stands, and Ac- to sound broadcasting. This will not occur cessories for 18 months at the very least, however, made I N S U L I N E CORP. O F A M E R I C A American Microphone Company, Inc. according to statements by RCA NEW Y 25 PARR PLACE YORK. N .9 California Corporation officials at the demonstration. 1915 South Western Avenue. Los Angeles. Calif. Please mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com 174 SHORT WAVE CRAFT for JULY, 1936 2 -Volt Short -Wave NEONTRON Superheterodyne INVALUABLE t Coatis wed 'rant page 1.13) transformers are pretuned or "peaked" at Guaranteed the factory which makes the final adjustment of the set comparatively simple. The 19 is used as a square -law detector because RADIO TUBES the author has been unable to obtain good results with this tube operating as a bias detector. The 3:1 ratio audio transformer at New and the output section of the 19 provide plenty of volume for comfortable loud- SHORTWAVE LOW PRICES! speaker operation on most stations. "Control" Line -up COIL BOOK As shown in the photographs, the set Complete Stock Ready for is built up on a 7x9x2 inch chassis, no Immediate Shipment front panel being used. The various con- Order Irons this page -Remit 220% with order. balance trols along the front of the chassis, reading C. O. D. All prices are F. O. R. FACTORY. Neeuk. left to right, are as follows: (1) volume Shipments go fonrard express or parcel post. No order for lean than accepted. control; (2) off -on switch; (3) "high fre- $3.00 quency" padding condenser; (4) "low fre- Guaranteed for 6 Months Licensed by R.C.A quency" padding condenser; (5) filament METAL TUBES rheostat. The mixer coil is at the left of Short Wave Coil Data Type Net Pelee Type Net Price Type Net Prie the dial; the oscillator coil is at the right. 6K7 S .79 6F6 S .79 38MG $.7 The method of mounting the sockets is for Every Conceivable 6A8 .79 6L7 .79 75MG .7 much the clean - 617 .79 novel and contributes to Short Wave Receiver 6C5 .69 6F5 .79 55A1 .5 cut appearance of the set. A drilling lay- 6H6 .69 25X5.MG .79 55A2 .5 out is shown in Fig. 2. 524 .79 -MG .79 5582 .5 43 RADIO ,P BSlEAiIONS Chassis Layout REGULAR TUBES "t Type Net Pries Type Net Price Type Net Pries The photographs and drawings should be studied carefully before any of the parts OOA 5 .21 46 5 .32 99X S .39 I OIA .21 47 .32 99 Std. .39 are mounted on the chassis. All of the IV .45 48 .79 W D 11 .55 parts have been placed in the position that 10 .79 49 .39 W D12 .55 gives the shortest and most direct lead- SHORTWAVE SET BUILDERS 12A .26 50 .55 1A6 .44 between them. The large or filament prongs 19 HAVE THIS BOOK .29 53 .44 IC6 .44 of are placed toward the rear MUST 20 .21 55 .32 2A3 .42 the four tubes 22 .44 56 .20 2A5 .32 of the chassis and the coil sockets are 24A .29 57 .32 2A6 .32 mounted so that the grid and plate leads IT is now possible for the ex- 26 .21 58 .32 2B6 1.13 are short and direct. It is extremely im- perimenter and short wave 27 .23 59 .44 685 1.13 portant that the leads from the tubes to enthusiast to obtain the most 30 .26 71A .26 2A7 .44 the I.F. transformers be kept very short exhaustive data on short wave 31 .26 75 .32 2B7 .44 and well separated, not to reduce losses, but coil winding information that 32 .44 76 .26 523 .28 from oscillat- has ever appeared in print. 33 .33 77 .32 6M (l a) .44 to prevent the I.F. amplifier 34 .44 78 .32 6A6 .44 ing. The by -pass condensers of both the As every experimenter who has 79 .40 647 .44 106 and the 34 screen circuits should be ever tried to build a short wave set 35/51 .29 well by experience, 36 .29 80 .22 687 .44 connected to the screen -grid terminals of knows only too between a and 37 .26 81 .55 6C6 .32 sockets themselves, and grounded di- the difference good the a receiver is usually found in 38 .29 82 .32 6D6 .32 rectly to the chassis. The end of the by- pour 3944 .29 83 .32 6E7 .49 the short wave coils. Very often .52 pass condenser having the band or marked you have to hunt through copies of 40 .21 83V 12A5 .69 these to find the 41 .35 84 .44 12A7 .90 "outside foil" goes to the chassis. If magazines, books, etc.. 42 .33 85 .32 1223 .29 precautions are not observed the 34 may information you require. 89 .32 2525 .33 oscillate or have a high noise- level. The Between the two covers of this 43 .33 find every possible hit 45 .24 99V .39 PZH .49 on IC6, 34 and 19 tubes are book you now shields used the of information on coil winding that MAJESTIC TYPE TUBES of the close fitting "jacket" type. In order has appeared in print during the past Type Net Price Type Net Price Type Net Price to obtain a "sure -fire" ground connection two years. Only the most modern for these shields, the author soldered a "dope" has been published here. 247S $ .83 75S $ .69 35S -SIS $ .55 No duplication. Illustrations ga- .79 55S short flexible "pigtail" lead to each shield 2B7S .83 6F7S .69 and to the chassis. This method proved to lore, giving not only full instruc- 2S -4S 1.19 6Y5 .79 56S .55 when tions how to wind coila, but dimen- 222 -G84 .83 624 .49 57S .69 stake the set much more quiet than sions, sizes, of wire, curves, how to 6A7S .83 625 .79 585 .69 the shields were grounded by means of the plot them, by means of which any íB75 .83 24S .49 6E7 .69 usual spring clip. coil for any particular short wave 6C7 .83 25 -25S 1.22 85S .69 set can be figured in advance, as to 6137 .69 27S .32 Mounting of By -pass and Fixed Con- number of turns, size of wire, spac- SPECIAL PURPOSE TUBES denser ins. etc. Type Description Net Price Type Description Price There has never been such data Net The various by -pass and fixed condensers published in such easy accessible 1828 Sparton type S .44 586 Sprrlon type 5 .79 and resistors are merely mounted in the form as thi 563 Spartan type .44 401 Kellogg type .90 position that gives the shortest leads and 484 Sparton type .44 403 Kellogg type 1.13 are supported by the wiring. An exami- FRIENDS PESTER HIM 485 Sparton type .44 686 Sparton type .68 nation of the photo showing the bottom Type Description Net Price view of the chassis will show that appar- Dear Sir: BH Raytheon type 125 mil rev. 51.13 ently all of the negative leads are merely I received your Short Wave Coil 213 Full wave rectifier .. _. .. __..._...... _._ _. .26 chassis, no "bonding" wire Book and am very well pleased. I 2168 Hall wave rectifier .. .90 grounded to the in case. This is true of showed it to my radio friends and Neon Tuning Lamps (single contact) .85 being use this now they are always pestering me for Neon Tuning Lamps (double contact) .59 only the battery and audio frequency leads. coil data, hi hi! 866 Heavy Duty .. _ _.. 1.25 All R.F. and I.F. leads are soldered to 866A Extra Heavy Duty 1.79 machine screws through the chassis and BERNARD A. DECKELM ANN. 11345 So. State St., CHARGER BULBS these machine screws are connected to- Chicago, Ill. Tyoe Net Price gether by a single length of bus wire. This 6 10 amp trickle charger bulbs flungar ttTrl .....51.65 arrangement gives a better electrical as 2 cop charger bulb with wire (tongue types 1.80 RADIO PUBLICATIONS well as mechanical return for these leads. HUDSON STREET 2 coop charger bulb without wire Ilutigar types 1.80 all of the connections are 97 and 6 amp charger bulbs aungar type l...... 3.75 Needless to say NRW YORK, N.Y. 15 amp charger bulbs (lumgar Upv) 7.50 soldered by means of a hot clean iron and TELEVISION TUBES. PHOTO ELECTRIC CELLS. rosin core solder. Radio Publications 7.36 r aq. cathode television tube 52.85 Three Dry Cells Will Operate Set 97 Hudson Street, 154" an. cathode television tube 3.85 New York, N. Y. :undo _.. 2.85 This receiver has been designed for oper- 1" set. cathode reileclron window Oise oils_. t Wave Coil Book, for ordinary dry cells as Please send i li tiately. your Short Cold cathode crater tube crater size .010 to .250 5.75 ation on three the whirls I elicit". .II 5e herewith (coin. 1'. S. stumps or money Photo electric cella (potassium type) 2'4 "lengthoverali 1.75 source of "A" supply. The filaments of order acceptable). Book la to be sent prepaid to me. Phetn electric cells (potassium type) 4' length overall 5.90 the 30, the IC6, the 34 and the 100 ohm Photo circl rie cells (caesium type) 315" length overall 3.90 resistor are wired in parallel and the out- Photo electric cells (caesium type) 41z" length overall 5.90 put of this combination is then connected Kanto Photo electric cells (caesium type) 868 type 3.90 to negative filament terminal of the Supersensitive Relays for above cells _ 2.95 the MAKERS OF NEONTRON TUBES 19 socket. The positive filament terminal of the 19 goes to the "A" positive and "B" Address ARCO TUBE COMPANY negative as shown in Fig. 1. By using this 227 Central Avenue Newark, N. J. parallel- series arrangement, the total drain City and State Please mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 175 on the "A" battery is only 0.26 ampere at easy to align and adjust for maximum per- 4 volts. The 500,000 ohm grid leak of the formance. The procedure of bringing the second detector should be returned to the oscillator and the signal- circuit into correct negative filament terminal of the 19 tube alignment is as follows: Place the 31 -50 rather than to the chassis. If the leak is meter coils in their sockets and connect &&tq HAM connected to the chassis an undesirable bias the antenna and ground wires to their of 2 volts negative would be placed on the respective binding posts. The proper volt- FREE grid of this section of the 19. Do not re- ages are applied to the grids, filaments and needr this aztat y plates of the tubes as shown in Fig. 1 and unit. the volume control (R2) is turned full on. Set condenser CP3 with its plates nearly all out and adjust CP2 for about 50% ó - maximum capacity. Now rotate the tuning condenser to the lower end of this band (about 15 or 20 on the dial) and try to pick up some kind of a signal. The 35 mmf. i condenser, CP3, is adjusted for maximum r signal strength. It will be noticed that two points of maximum signal strength can be found - one with the plates nearly all out nd another with the plates nearly all in. Re- gardless of the band in use, the unmeshed position is the correct one. The tuning condenser is now turned to about 75 or 80 and CI'2 is adjusted for maximum signal volume in exactly the same manner as was done on the lower end of the tuning scale. Once the two padding Tins great, new catalog is exclusively condensers are ad- for justed, CP3 should not be bothered; any hams and experimenters. It's written BY amateurs FOR amateurs. necessary readjustment can be made with CP2 which is much less critical. No matter what you may need you'll The oscillator coil values have been find it here at lowest "WHOLESALE" prices. Receivers, X'mitters, Kits. Bottom View worked out so that little or no "re- tracking" Racks, Tubes, and parts by practically of the oscillator is necessary when cluing - every leading manufacturer. you ing coils! In fact, this super is just .I.; If more either the 7C6, the .10 or the 34 tubes have not received your Free copy simply easy to operate as an ordinary straight from their sockets while the "A" current ask for Catalog No. 60-Gill on your is turned on! regenerative receiver, using only one tuned card If one or more of these circuit. QSL or if you have not yet re- tubes are taken out during operation, the ceived your ticket, a postcard will do! current drawn by that tube is forced to Ordinarily very little realignment of the find its way through the filaments of the I.F. transformers is necessary as these are remaining tubes in the parallel combina- "peaked" to 456 kc. at the factory. How- tion. This additional load may shorten ever, a slight lining up of this circuit will their useful life. increase the overall sensitivity of the set RADIO SERVICE if the original settings have been disturbed. WNOIESALE (3. NEW H.Y. Checking the Wiring The procedure for I.F. alignment is as YDEL follows: Tune in a weak station (the 10a SIXTH AVE. After the set has been wired, the wiring weakest that can be heard in the phones) CHICAGO. ILL. ATLANTA, GA. should be checked by referring to Fig. 1 and, with an insulated screw -driver, ad- 901W JACKSON BLVD. ROW RADER=ST NW before the batteries are connected to their just the trimmer of the grid section of the BRONX-11X NEWABX.N.J. leads. It is a good idea to close both the output transformer for maximum volume. 547 L FORDMAM AD. 219 CENTRAL AVE. filament and the "B" negative switches and Now adjust each trimmer in turn, w)rking test each from "B" positive lead to the hack toward the mixer tube, until a I four chassis in order to determine whether any short- condensers have been "peaked" for maxi- circuits are in existence. A pair of mum sensitivity. If the signal becomes SPECIAL! headphones and a 4!i volt "C" battery are very loud during this alignment process, Lafayette 4 -Tube TRANSCEPTOR com- satisfactory for this purpose. If everything tune to a weaker station! Do not reduce pletely wired and assembled. Bat- has been wired properly, a loud click will the volume by turning clown the volume teries and Tubes extra! On sale S275Ú be heard the first time the connection is control! It must be remembered that in at all our branches listed above. i - made and no clicks or very weak ones all cases signals must be received before Wholesale Radio Service Co.. Inc. should be heard on successive contacts. If any attempt is made to adjust the I.F. a loud click is heard every time the contact circuits and under no circumstances should is made and broken a "short- circuit" exists the padding condensers be disturbed while or the plate or screen grid by -pass con- this process is being carried out! It is densers are leaky. usually necessary to go over the I.F, trim- mers two or three times in order to adjust Aligning the Various Stages Easy this circuit for maximum performance if This short -wave superhet is extremely any realignment is required. Hints on Tuning for DX Stations - A few suggestions on tuning this little ONLY 3 TYPES OF set be I}'-i-- 1FT xs--T may pertinent. This receiver is 2#'--1 extremely sensitive and may be operated 1 1 I COIL SOCKET I f, satisfactorily on a short antenna, except aulamatic regulators are required lore. SOCKET NOCE I I when extreme DX reception. place any of the 30 types of ballast tubes L_ sii..-_J tuning for The 50,000 ohm potentiometer in the screen used to A.C. or D.C. sets. NEW LOW PRICE / wcuT l- circuit of the 1C0 serves as a combination Lift. 51.25 WRITE FOR / I KU es ,nies A9.OIA. MOLE OM. CONTI volume and sensitivity control and gives a Alm Iol, en replacement. for 3 -Yea CHART CV. better signal -to -noise ratio when retarded Dann, Se . Lam SI.FO J/eCIA MOLE Ië sw1TCMI slightly. The operation of this control has IFT1 a slight effect on the tuning of the oscilla- Ye°DpIIOLE (NI-FREa \,f-- 1 _f _ tor (about the same effect as the regenera- 1}' tion control in the average regenerative circuit) and the circuits can be re- tracked -o----®t1N i,. TaNING 1 L- by a slight adjustment of CP2. The ad- 5[e[ CONDENSER af 1 19 justment of this particular condenser is so -1- SOCKET 41- ROLE 'broad" that it may be turned through s/a-aM L-_____J _ MQE (LO its full 180 degrees without throwing the EO ~MAI SO SOCKET _ "OLE R.F. circuits out of alignment. /CÖII JI MOLE - FOR LEADS Tune S- L- O -W -L -Y ! The time worn admonition to "tune slow- ly" also holds good in this case. The dial Amer Ira's leading short u "0 receivers- rulers of the HOLE 11 air! No ether sono nnirar Ion receivers oller you the (SOSO) tr A.FT. shown in the photographs is 10:1 ratio and saule adeant alms and nor en ìrnre at the same moder- 2 ate priers that anyone l'an :Mont. Metal tubes. ITMI 21' is fairly satisfactory. A good high -ratio tirplane type dial would be more desirable. oltre I.F. roils. No pi tg -hl ndl,. Mlrn. -T 'em ter Dinh -}sert ro- Meehan leai band sureall -- Ihlilt -ht r" Most short -wave fans will be surprised and Poster Parks and Speakers. See these amazing re- pleased at the way this "2 -volt superhet" ceivers at your Jobbers Imlay or virile A V2'NOLE FOR YAMOLE FOR J1 .12 v2 -MOLES FDA ANT. POST ONO. POST TIP JACKS brings in the "foreigners" on the 25, 31 l'OMSTT'NIt'.\TION DIVISION ALL SOCKET SOLES I' INA. and 49 meter bands, even when the powerful American stations are operating on ad- THE HALLICRAFTERS, INC. Chassis Layout jacent channels. MARION, INDIANA Please mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com 176 SHORT WAVE CRAFT for JULY, 1936 The author has operated this receiver IIh9tl!rktnglA// over a period of about ten days before writing this article. No exceptional DX .. reception has been received, simply be- 1s _4U_ cause we have never tried for long distant DATAPRINTS stations. However, all of the usual Amer- ican and "foreign" broadcasters, such as Just the W2XAF, W1XAL, EAQ, GSC, DJA, HBL, etc. have been received with ear -splitting AV/ CONSTRUCTION volume on phones, and fairly good volume on the loud speaker. On the 20 meter Information amateur phone band, stations have been heard from all parts of the U.S.A. and Canada as well as several Cuban, Costa You Need Rican and South American "hams ". On occasion that the author has oper- To Build Election year - si zzli it iral campaigns -the every biggest Public Address opportunity ever! Panales- ated this receiver, day or night, the bands rallies- stump!tag cant pa igns -upset logs -they all have been "simply alive" with stations. Electrical meet and want Public Address. Get your cat of (For "Ham" use, the set can be fitted this tremendous gate. Tie up with ALLIED - 2 ft. Spark we'll help you sell quality sound equipunut at with one of the new Crowe double needle Oudin in Apparatus big. profits. "bandspread" dials, which feature could Action! also be used to advantage by the "Fan" for FREE! SPECIAL POLITICAL tuning in the closely -packed S -W broadcast TESLA OR OUDIN COILS P.A. SALES BULLETIN Dataprint containing data fer constructing stations in the 6 ni.c. (49 meter) band, this 9 ft. spark Oudin -Tesla soll. Requires Send fair this vuluaób pew P.A. sales - etc. -Editor.) I K.W. 20.000 volt transformer as "exciter "; $e Includes condenser data. . , 75 promoter now. l'unclo : value- pncktsl. see Ilst below. Sells complete mntnd outfits for 5011 - List of Parts 8 inch spark, data for building. including con- portable, Mobile. laruoppent -a job for K. W. 15.000 volt sound 140 denser data; requires t, every political need. Get wet for CI -2 -gang tuning condenser, mmf. each transforma; see Wl below...._ 0.50 the ttnuing campaign-the hottest In section. Hammarlund. -- Violetta type. high frequency coil data: 110 ears. Send for this FREE special C2 -Mica fixed condenser, .00025 mf., Cornell volt A.C. or D.C. type: 1" spark; used for Political P.A. Bulletin! Dubilier. "violet ray" treatments and ' '34

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 177

1- Tube -1- Crystal -4 -Bands ! (Continued from page 142 BRUSH S'phetica/ where grid current flows during a portion power output when using the 6L6 as an of the input cycle, two of these tubes will oscillator -doubler! Microphone deliver 60 watts of audio and the peak grid This great amount of power obtained input power required is only 350 milliwatts. when doubling, lead us to believe that the The foregoing, together with the illustra- fourth harmonic might be worthwhile cul- Porremote pickup, "P. A., "com- tions of the tube, showing different stages tivating. Examination quickly proved this mercial interstation and amateur of manufacture, together with the drawing a good hunch and we find that the plate use. Low in price...but built to indicating the electron beaming, will give current took a dip from 85 ma. to 42 ma., Brush's traditionally high me- was greater chanical and electrical standards. the reader a fair idea as to just what this and indications show that there Wide frequency response. Non - tube is all about. than 5 watts output on even the 4th har- directional. No diaphragms. No Immediately, of course, the question monic! distortion from close speaking. arises as to what a tube of this type would So at last we have a tube in which we Trouble -free operation. No but- do for the amateur (Ham) besides pro- can quadruple the frequency directly from ton current and no input trans- viding audio frequency power. Tests run an. 80 -meter crystal and have sufficient former to cause hum. Beautifully on a single tube as a crystal oscillator power output to excite a fairly medium finished in dull chromium. Size showed undoubtedly that this tube is des- powered amplifier tube! Operation with a only 2% inches in diameter. tined to become more popular than the 47, 40 -meter crystal gave practically the same Weight S oz. Output level minus as will be seen in the table. 66 D.B. Locking type plug and or 59 ever hoped to be. The data compiled results, socket connector for either sus- and shown in the table is for a single tube, No attempt was made to bring out the pension or stand mounting at either in the tritet or straight pentode 10 -meter harmonic with a 40 -meter crystal. no extra cost. Full details, Data connection, with 500 volts on the plate But the test oscillator worked the Pacific SheetNo.13. Free. Send for one. and 280 volts on the screen, with a grid Coast on 20 meters using a 40 -meter crys- leak of 150,000 ohms. In the table, plate tal! Undoubtedly there will be a number of current is given in two values, "R" indi- other uses for this tube and many combina- cating at resonance and "OR" -off reso- tions using it will be suggested. We hope nance. to present a more elaborate transmitter BRUSH , p / With an 80 -meter crystal we find that using these tubes in the next issue of in the straight tetrode connection, the Short Wave Craft. Unquestionably, it is plate current dips down to 10 ma. and goes the most valuable oscillator tube which has up to 85, off resonance. The screen voltage been offered the amateur thus far. Microphone was 280 and the screen current 9 ma. with 61.6 Crystal Oscillator Plate Voltage 500 For after dinner and convention the plate circuit unmounted. The measured - Gives output was 20 watts. Imagine an oscillator Grid Leak- 150,000 Ohms With 80 speakers, lecturers, etc. Meter Crystal great mobility. The smallest. providing 20 watts output with only 30 lightest microphone on the mar- plate input! In each case, when the Connection Plato Current SG SG Watts Watts watts In- Out ket. Size 1% x 1% x %. Weight plate circuit was loaded to maximum output put with coat attachment less than put, the screen current drops to 5 ma. So Tetrale a OR Volts current* 1 oz. Special internal construc- have 1.4 watts 10 Ina 85 ma 280 9 ma 30 20 outer here we approximately Tritet tion and rubber racketed screen dissipation, 30 watts plate input and (2nd Har.) 15 ma 85 ma 280 10 ma 30 20 case insure quiet operation. No 20 watts output! In the well -known tri - Trite! interference from breathing tet circuit, doubling in the plate circuit (4th liar.) 42 ma AI ma 200 9 ma 30 5 noises, etc. Typical Brush sound with 40- ureter ,-estai cell response and trouble -free provided a tremendously strong second har- Tetnole 10 tea 85 ma 280 9 ma 30 20 rnonic; referring to the chart we see that Second 1lannen is operation. Details on request. the plate current dips to 15 and goes up Tritet Is nia 85 eta 2280 9 ma 30 18 Note:- Screen current T, when plate circuit Is fully to 85, and the power output is 20 watts. loaded. Screen input 1.1 rl salts There appeared absolutely no decrease in with no plate load. tear l 40,. n caoPHONE: MIKE VIANDS ., WESTER, HEAD PHONES LOSES SPEAKERS Short Waves and Long Raves NalrtsNAl cA.ARNTII IN ALL .R RAOIO tl (Continued f roar. page 146) UNCLE DAVE'S STEPHEN CASEY, W2IIR, PERTH s.:1.7.1.1".._ SNAiK GOOD NEWS FROM RHODESIA, WAY- Aa.aAAaY. raY..YS.A SOUTH AFRICA AMBOY, N.J., HAS A -1 STATION Liberal allowances on your old receivers to- wards the purchase price of any of the fol- one former, for economy or other reasons, and crystals whose frequencies are at the when they to modulate the carrier the lowing new receivers: end of the band. The result is that there try NATIONAL HRO RME -69 plate voltage and current varies on the NAMMARLUND SUPER PRO RCA ACR -175 is a big slice of the band left to listen for final. PATTERSON PR -12 SUPER SKYRIDER DX in. If a man has signals with keyclicks If they try this system, it will work very JUST A FEW LEFT! Peerless 3 -tube 31 nett high is acid. The Rhodesian gain amplifiers. lesa speaker, microphone and he boiled in battery nice as long as they are not over -drawing at tubes stations are 100% crystal -controlled, so if the transformer rating. LISfITVI) SEI'l'l'LY . ORDER NOW' anyone hears a non -crystal note, using the If my fellow amateurs wish to BLILEY 20 -meter type 1.1F -2 crystals. fully mounted. exchange in Oak, net 57.50 ZE call, don't work him as nothing under photographs of the "rig" or "shacks," I will Cable Address "Uneledave" T8 is radiated from this country. be very glad to do so. Long Distance Phone 4 -5746 The receiver is a battery -operated TRF- Regarding your magazine, Short Wave Include 20% deposit with c.o.d. orders LF contraption, which "works." As Craft, I hope that you will continue the fine Prises F.O.B. Albany Foreign Trade Solicited Det-2 Send for new Ham Catalogue -just out.' one can buy n good second -hand motor -car work you started a long time ago for the for the price of a HRO National receiver, radio loving public and radio amateurs. such receivers are scarce and we have to Very 73. make the best of what we can get. Still STEPHEN CASEY, W2IIR, BUILD YOUR OWN it's great fun -the kick the W's have be- 901 State Street, ELECTRIC OUTBOARD MOTOR Perth Amboy, N.J. hind their signals makes up for the lack of Prom old auto generator. we sho you "Single- Signal Supers." (11'e are very glad to publish the photo how. \lake money building for otl.'r.. I get your magazine every month from Variable Speed. Light weight and Silent. of your excellent transmitter and shall be Operates from 8 to 12 hours the Salisbury Herald Bookstore and I wish pleased to have you write some other ar- on ordinary storage battery. Short ll'avc Craft the best of luck, 73. Dime brings nmtplete sineu 1,... ticles, describing in detail the makeup of Milled and catalog. Yours sincerely, your transmitter and also some of your ex- plans periences, and the types of receivers you LEJAY MFG. CO.. 1517 W. Lake. Minneapolis. Minn. R. JVRB, ZE1JN, found best. not The Observatory, 16 Lawley Road, have Do forget also that S.A. tee pay for all constructional articles pub - Manufacturers of Bulawayo, Southern Rhodesia, li.fhed in Short Wave Craft, and that we (Greetings! R. J., and from the photo it always are on the lookout for good articles VITREOUS TRANSMITTING GRID LEAKS appears that you have a very efficient of this type, giving full circuit and other VOLUME CONTROLS POWER RHEOSTATS short-wave transmitting and receiving sta- details and photos of the set. Other topics, such as tuning up the antenna to the trans- tion. You might like to write an article or Write for Complete Free Catalog so for Short Wave Craft, and we imagine mitter, cte., form "live" subjects also. - a description of the antennas you may use Editor.) ELECTRAD, Inc. when snaking your long -distance contacts 175 Vorick Street, New York would prove worthwhile to the readers of this magazine, giving all the dimensions Don't Miss the August Issue! and elevations of the antenna wires, type Lots of Features for See Pages 180 and 192 for of coupling used, and the direction in which the antenna points.- Editor) S -W FANS! Remarkable Subscription Offers Please mention SHORT WAVE ('nArr when writing advertisers

www.americanradiohistory.com 178 SNORT WAVE CRAFT for JULY, 1936 RADIO INSTRUCTION You Can Become a Fast, Capable RADIO OPERATOR at Home Radio Amateur Course ° RADIO (Continued from page 155) REAL RADIO ENGINEERS! With the Famous CANDLER liltned in this discussion into a 3 -tube re- Scientific Sound consisting of a pentode, R.F. ampli- System ier, pentode detector, and triode audio lIm- That Trained (tlifier. In tuned R.F. circuits of this type. shielding is necessary as indicated in the r Champions diagram. This should separate the two Ted McElroy stages completely. Kendall Clough The input to the R.F. stage is also induc- Chugh.ibengle Co. MANY R -T -1 TRAINED MEN . and Jean tive and when a doublet is used the dotted E. E. Gramat j, Earn Up to $75 a Week and connection between the antenna coupling Standard Tear Co. More 1- Hudson coil and the ground or "B" negative is not Karl E. Hassel These industry appointed corn...era. _ Chief e:nt:neer, Oho wrk for large radio t urao í made. This connection is only made when Zenith Radie Corp. turors, ` s - CANDLER will supervise your Training - an antenna and ground combination such H. C. Tittle at Ipnne. ¡Hid ready 1 -at- SYSTEM ,Chief Hann Seilo',. gel you for Waal- as the Marconi antenna is used. "renw Radio pay Jobs it Radio Broadcasting. In- -,; taught at stallation. . F. :warirhlg. Public Address HARVARD O. Whitten Me e Ate r. Philp,, Sesnut and I7pno Flirt Pell work. UNIVERSITY Radio & Talev. Core. Also for mining activity in Telrv1- by McElroy M. slat. Opportunities for pmpwrly 400 Megacycles Used Dr.IC. rwrineer trained corn better than ever before. 'l'e Tearh You Everything Necessary to ar- P. R. Mull,, y & Co. Kant uh Ile you barn. !Witte make $5 able you to obtain your " lfam" License quick- ant $10 a week extra In spare time ly, easily, inexpensively, 50 Big Radio Con- corneks after tan ine. Tell us what you by French "Hams" Manto,y earn up to 575 a week In full need. Fastest Amateurs and cerns Endorse R.T. time Ì,ba or their busineaa. Com'I ops . th r training Were CAND- (Continued from page 140) you want LER trained.wLearn Code ms' crag RIGHT with the SYS- (HB9RDL) several novel aerials were TEM that taught the i evolved for both mobile and stationary RADIO AND TELEVISION INSTITUTE Champions! units. The antenna shown in Fig. 6 is a Dept. 21 -B, 2150 Lawrence Avenue, Chicago, III. FREE New BOOK OF reflector system resonating at 3 meters FACTS for Beginners. who t: with the oscillator located at the optical want to learn code. c m'I ops and amateurs who ant to in. focal point. This unit consists of a group crease TA N OLER them speed quickly. e C,w of rods connected together and each reson- RADIO or MORSE CODE easily. Contains stories of ating at tiz the Easy to Learn with the Champions and informs. BOOMd;iACTt transmission wavelength. INSTRUCTOGRAPH tiro that will help you. A eon The entire group of rods is arranged in a card will bring this valuable Redie OPeeetes parabolic curve with Code Teacher BOO K to you. No obligation the aerial at the focal The nog /tract Ica! .short nn point or slightly beyond it. The use of the to masteraster cale. qualify for CANDLER SYSTEM CO. Om - exams., i od lower frequency (:i meters) for the reflec- your Dept. S -7 ASHEVILLE. N. C. speed. I tor allows more flexibility in the trans- sepals yon p,'' mission frequency than when it is tuned to Si. the quarter -wave lire vhenn or half -wave . ." MAC KEY @ $7.95 finest speed key point. always dy Tuns._ Figure 7 shows an interesting type of model e rSeti for or built; MAC OSC @ $3.95 ac ,s /dc oscil- antenna used in the experiments which is conomy ilh lator. Tone control; MAC CORD $1.00 Ihtnk of Inetnrtions. Tut credited to Marconi non. bile navy spfn speed key cord; MAC MA- by M. Luthi. This or rent. at lo, directional aerial consists of a series of fcost. Jost send ruts ' -tard RINE receiver 550-850 meters. r u or complete :lets i Is most intd? half -wave rods arranged a Few deluxe MAC KEYS @ in such manner to- $15.00 fm me that the entire resonant frequency INSTRUCTOGRAPH di. Wri me. T. R. McElroy, 23 Bayside is equal to twice the resonant Company, Dept. SW-7 St., Boston, Mass. u frequency of any one »- If by Mav Key wri rod. The use of this series 912 Lakeside Place, Ct :caoo, lu. me for xmy ipt & dsrh ifn. connection in- ,. ut.r :s.,, creases the radiation of the system over a Radio College of Canada, Ltd., 863 Bay st., Toronto single half -wave resonator. THE PERFECT Another interesting radiator is shown in Fig. 8. In this case, each of the open cubes formed by the crossed wires, forms a lea Mill /ON EXPERT reson- LEARN TELEVISION CODE TEACHER! ant circuit which is tuned to one- fourth of WITH RADIO NOW! the transmission I Iireu' opportunity! .et rads for the hot J lobs i ._.NEW MASTER TELEPLEX_... frequency. In the case of Radio, I etc.inons w ceps the country. Tu, a bog im this antenna, th? outer cubes act as re- h I onion. ( ana l es perncen averno,'ir Si rtlelteed operators, aand flectors, so a \\ X \I I .,rit, ala t m \\'tXOY. - to le that strongly polarized wave Irani i to sr l U .. ,:.I literature showing actual via t :l. Tins amazing new instrument will rosonl your is emitted. Sonic of most t leril ending the distant trans- ..n g opportunitly >. etc. , double me perforated parpaper and re- missions with 400 me. t I the rig of HB9AO ,...al I tuck A at nv , .: I t n ¡b. P., In non FIRST NATIONAL TELEVISION, INC. were accomplished with this radiating sys- Dept. e -7, v.,,.,., e L:tit Bldg., Manses City. Me. NO BATTERIES BUY IT OR RENT IT tem. NO WINDING Perhaps the most astounding fact in ALL , stn host to these interesting experiments ELECTRIC -., . of two . or this instrm. French amateurs is that communica- A D I O I.w yiwng -not i' h, al" II , . u It t`hllo Hit ,:r: tion was actually established beyond optical i ENGINEERING, " I d,, aniItul wrttiou d ,,nnplete course and range distances (line -of- sight) on this un- broadcasting. aviation and pollee radio, servicing. ma- J.: puliti to the \Cheat -, Meal fnstruetiou It it! rine radio teiegraphy and telephony. Morse telegraph, u trey -bark guar.ir I. usually high frequency-but rather that ',toile Perfnrn for anti I and reliwq accounting taught thoroughly. Engineer- Iunv nest. easy si the equipment and tubes were parts which Transmit ter. w h i c h ,lay ing course of nine months' duration eguiralent to three t\llte for iuhu :. . were readily obtainable on of soilage radio work. All expenses -I ,rpm $1,000. the market. low. Cata- elan. And remember -the signals -both voice log tree. School established 1574. and buzzer -modulated C.W. were picked up Dodge's Institute. Turner St., Valparaiso, In&. TELEPLEX CO. with R9 strength -no "imagined whispers" 72 Cortlandt St. New York City for these hams! RADIO ENGINEERING The New Master TeItpler "The Choice of Those Who Know- RCA Institutes offers an Intensive course of high standard embracing all phases of Radio. Prac- tical training n ith modern equipment at "{HAMS" TALK TO ENGLAND New York and Chicago schools. Also spe- COLLEGE cialized ur e Homemme Study Course. ON 5 METERS! under "Nos obligation'' plan. Catalog. Degree in 2 Years Dept. 5 5V -16. A 3450 mile two way short -wave phone Complete Radio Engi- conversation was carried on betwe. RCA INSTITUTES, Inc. 75 VariC Mercüan dseeMa Chicago neering course in 96 four amateurs in Troy, N.Y., and a Rino+ Smocci.,I :e 54 t. weeks. Bachelor shalt . of wave station in England, Science Degree. Radio according t (television, talking pic- press reports dated April 15. R. W. QUICKWAY tornake money in tures and the vast Schermerhorn, Malcolm Hormaats Modern receivers are electronic field) offers urn steal opportunities for and Frank Granger, of Troy, and Joseph demanding men with trained radio engineers. Courses also in Civil, Wright of Watervliet, are the young men RADIO modern training fer Electrical, Mechanical, Chemical. Aeronautical, concerned in this record -breaking 5 -meter rem -o w,rk. New training method Engineering; Business Administration and Ac- and semi,/ equipment offer starts counting. contact established across the broad At- Low tuition, low living costs. World lantic. You earning almost et once. Up to $$ famous for technical two -year courses. Those who an hour easy in a short time. write lack high school may make up work. Students This reported 3450 -mile jump on the today cor FREE book of details. from all parts of the world. 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www.americanradiohistory.com SHORT WAVE CRAFT tor JULY, 1936 179 "Ham" Antennas for the Low Frequency Bands By : RTHI'R H. LYNCH Data for Making Half Wave Doublets Suitable wall, the voltage breakdown between con- for Receivers As Well As Transmission ductors is very high, being well above Up to 250 Watts. 25,000 volts. THE business of providing amateurs Another and entirely new type of an- with doublet antennas for transmitters tenna wire is being placed on the market has, up to now, required more than ordin- and it is made up of 42 strands. It is ex- ary mechanical ability and the proposition tremely flexible and very easy to work. has resulted in a considerable expense. The new antenna wire clamps, shown in the The arrangement shown eliminates a lot insert, make it possible for the "ham" to of the difficulties which have existed in the provide himself with an antenna which is HRO JUNIOR past and provides the "Ham" with a ship- perfectly free from loose contacts, although shape antenna, which is both rugged and it is not necessary to use solder. The SUPERHETERODYNE inexpensive. manner in which the clamps are attached The and possibly the most import- to the antenna wire, as well as to the lead - The 111t0 JnmIor Is 1, rlq.cr h.bralrnr re- first, ceiver, ontatnndluq for Its t -,ihure 1,11,1 low ant, recent contribution to low frequency in wire, are shown in the insert. price. It Is designed expressly for those who "ham" radio, has been the introduction of The impedance of the transmission line ro Interested In world -wide short wave weep- a new Cable. By the elimination of all fab- is matched to any half-wave doublet, no Gin, and who demand the performance of it whether it is for use on 20, 40, onenerrinl -tie receiver. but olio not require matter the highly si seebi lizwl features that necessarily 42 STRAND 80 or 160 meters, by maintaining the di- WIRE nenvev the cost of a receiver designed ex- wiRE CLAMPS ANTENNA mensions, which are shown in the triangle pIi ssly for two -way commercial service. in the center of the figure. A nine tube circuit Iluolat1111g two stages The two quarter -wave portions of the of preselection and two stages of I.I'. with made longer air dielectric trimming condensers), a pre - antenna proper are slightly risiun ballt taring condenser. separate shielded than a quarter wavelength each and they 'rils. and strict adherence to \utlonnÍ's high NAVY STANDARD A0 INSULATORS are gradually reduced by manipulating the standard of quality permits the attainment of new antenna wire clamps at the two out- surpassed selectivity and sensitivity. Lab- until the total oratory Calibration of each coil range. plus the side ends of the antenna, luign easy-rending tuning dial Imo perplexing over -all length brings the antenna into i aterminghd tuning wades l Deo'h !es an ac- resonance with the crystal frequency of curate means for logging aid locating stations. ANTENNAIRE Fast or slow tuning is , eougdisIied by the IMPROVED -' CLAMP the transmitter. clever arrangement of the tuning drive Meehan. 'G,ANT-eILLERCABLE This procedure eliminates the necessity on. I tally one knob Is used -no Unhandy Detail of Antenna Here Described for cutting and a lot of extra soldering. double or twv, position knobs. been found that For those desiring the speelsllzed features of a In a few instances it has crystal filter. N meter and amateur bawl spread. we ric, the "wick effect" which has been both- obtaining the correct impedance match be- cud the standard hilt)! have been using other ering amateurs who tween the transmission line and the tank r winite for an illustrated description of bah re- types of twisted -pair lines, has been thor- circuit of the transmitter, has required a ecivers. oughly eliminated. The use of stranded delicate adjustment of the coupling. wire in each conductor makes the entire flexible. Pure Laytex is In many cases this adjustment has been NATIONAL CO., INC. assembly quite greatly simplified by placing a .0001 mmf. MASS. used for insulation for two reasons. variable condenser across the lower end of MALDEN, First the outside covering on each con- line. ductor may be made extremely thin, and the transmission for that reason the surge impedance of the This article has been prepared from data 82 supplied by courtesy of Arthur H. Lynch, line is kept quite low -approximately 215 to 1 BANDSPREAD ohms. Secondly, in spite of the very thin Inc. MAKES What Does It Cost to Become YOUR an Amateur? SET (Continued from page 157) EASIER transmitter, for radiophone work you must creased price. It is still the same trans- TO have a good quality microphone, speech am- former and the purchaser should govern his plifying equipment, and a modulator unit, selection by his pocket -book, confident in TUNE! all of which involve a rather substantial the knowledge that for performance pur- financial outlay, even for a very low - poses he will find either type identical. A Reap Precision Inst rument With Micrometer Drive: ob- Be guided, if possible, by other amateurs Ni , clatter shat kind of radio set you nail. It ti ill powered radio telephone. If cost is no he ititpltselt wt uh this 211 to 1 ratio llandsprrad 1 ject, well and good -you may expect to who are more experienced in their hobby in. Dial. Ilmuretla of stations you have timer e spend for a low- powered phone, suitable than you. When this cannot conveniently heard of the crowded short scare Letitia Can Dow t Is well - easily trued for consistent communication over a couple be done, put your trust in a reliable Make your nether a laboratory Instrument! Mom,. of hundred miles on the so- called "160 established radio supply house that sponsors In a Jiffy: weds only one screw bole Fits any ..' where your first operation no outrageous or "discounts." or 56 shaft. glade of gelatine Bakelite. alum - meter band," guarantees umut. and r tekletl brass. Friction clutch 111,11 1 will commence, approximately one -hundred To enter the amateur radio telephone vernier at will for coarse tuning. Regular prirs u dollars- divided as follows; a radio fre- field in a small way with equipment that ytount this dial on your front panel and I.r... ., rce OW y - be proud! quency unit, which must he a stable, modern will be acceptable both to the Federal Com- ORDER NOW! QUANTITY LIMITED! CW transmitter preferably crystal -con- munications Commission and to the amateur SPECIAL POSTPAID PRICE 79c $50 for at large, you should be prepared Two for $1.25 trolled, with at least three stages, fraternity GUARANTEED -Money Back If Not Satisfied! parts. The modulator unit for such a phone to spend at least one hundred dollars. Your ACE RADIO LABORATORIES, will take another $20, the speech amplifier ability to pick up good used equipment from 1619 Broadway. Dept. SW.7 N. Y. C. about $7.50 and the balance of your hun- other amateurs together with your con- dred dollars will go for the microphone and structional genius will enable you to reduce accessories such as the crystal and holder this figure quite substantially. A REAL POWER PACK at an unusually PRICE and also the transmitting antenna equip- A Low A CW Transmitter Cheapest to Start i Only 100 Model X left ment. 325 Volts PURE DC at 50 Milli- With 153 amperes and 2 Volts AC CT 5 Look Out for "Bargains" p Amps. Completely cf I . á heavy el chas- Remember, in this discussion we are con- If you are short of funds do not be dis- sis. finished in brown crackle. neces- A rare bargain. Uses type 80 sidering only GOOD apparatus, of reliable mayed by the above figures. It is not tut. hurry. betere they are all you enter upon your amateur m. i... manufacture-it is true that much equip- sary that SPECIAL PRICE, only ment may be had at "so- called" bargain activity as. a "phone man." You must learn prices, but unless the purchaser is familiar the code regardless of whether you plan to General Engineering Corp., Dept. S -7, Charlotte, Michigan with various items or apparatus and their use phone exclusively or not and with customary prices or is dealing with a re- limited funds, it is entirely possible to build putable supply house, he can go far astray. a simple, though efficient radio -telegraph Accordingly we are recommending that the transmitter; adding to your equipment as CALL LETTERS entrant in this field purchase his first equip- you can afford to and eventually acquiring to dross up your station. Beautifully mounted ment only from houses of established rep - the outfit which you desire. This can be on large glass panel and attractively framed. the simple equip- Letters d embossed real gold or slim. utation-he will find a large choice and done in such a way that 25CWonted nw1aleto and sent postpaid. only varying price range at most radio supply ment with which you start, need not be g a letter. Sneeify gold or siner. -Order stores. A transformer for example, may be discarded as your outfit advances, but be- direct, enclosing remittance. uncascd at a low figure, or supplied in vari- comes incorporated therein. G. F. EION CO. 1606 N. Paulin It, Chicago, ILL ous styles of enclosing housings at an in- (Continued on page 181) Please mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com 180 SHORT WAVE CRAFT for JULY, 1936 When to Listen In By M. Harvey Gernsback (All Schedules Eastern Standard Time) HOLLAND Press Wireless, Inc., who operates a 3:50 -8:05 a.m. on DJB, 8:05 -11 a.m. THE Dutch stations made another large number of telegraph transmit- on DJA and DJB. From 1:30 -3:30 change in their schedule on May ters at Hicksville. a.m. DJR and from 5:45 -7:30 a.m. 25th. PHI on 17775 kc. is on daily DJL. Both of these last two are ex- except Tues, and Wed. from 7:30 -9:30 AUSTRALIA perimental. a.m., with its regular programs for the A new station will shortly take the For Africa, 11:35 a.m.-4:20 p.m. on Dutch East and West Indies. On Sun. air in Western Australia. It is DJD and DJC. 12 n -2 p.m. on DJP by it is also on from 1 -2 p.m. with a pro- VK631E, operated the Amalgamated and 3 -4:20 p.m. on DJO. The last gram for Africa. PCJ on 15220 kc. Wireless of Australia, Ltd. The new two are experimental. broadcasts a program for East Asia on station will be located near Perth, W. From 4:50 -10:45 p.m. DJD is on for Sun. from 6:30 -7:30 a.m. and broad- Australia. It is expected to operate N. America, DJN for S. America and casts experimental programs on Tues. on the same frequency as VK2ME at DJA for Central America. In addi- from 4 -6 a.m. and on Wed. from 7 -11 Sydney, 9590 kc. It will broadcast the tion DJM is on experimentally for N. a.m. PCJ on 9590 kc. broadcasts each same type of programs as 231E. This America from 7:30 -9:30 p.m. Sun. for South America from 7 -8 p.m. station will be in operation by July 1st if all goes well. TIGPH The most important news is that PCJ A LETTER from the Director of on 9590 kc. is now broadcasting ex- ENGLAND TIGPH, "Alma Tica," Apartado perimental programs each Wednesday THE Daventry schedule for June 800, San Jose, Costa Rica, gives the from 7 -10 p.m. This marks the re- is as follows: Trans. 1, 11:30 p.m.- following schedule. Daily, 11 a.m. -1 turn of these famous programs to the 1:30 a.m. on GSB and either GSD or p.m., 6 -10 p.m. This station relays air after an absence of about 5 years GSN. Trans. 2, 6 -8:45 a.m. on GSG and long wave station TIX each evening as PCJ has not been operating on 9590 GSH or GSJ. Trans. 3, 9 -10:30 a.m. from 9 -10 p.m. kc. since 1931. on GSG and either GSF or GSJ; 10:30 PANAMA FRANCE a.m. -12 n. on GSG and GSF. Trans. A NEW station is reported at Colon. RADIO Colonial is now operating 4, 12:15 -3:40 p.m. on GSB, GSD and The call is HP50, address is Box 33. on "summer time." The schedule GSI; 3:40 -5:45 p.m. on GSB, GSD and The station operates daily from 7:30- 1 -4 kc., is a.m. on 11880 (TPA3) either GSO or GSG. Trans. 5, 6 -8 9 a.m., 12 n. -1 p.m. and 6 -9 p.m. on 4:55 -10 a.m. on 15245 kc. (TPA2), p.m. on GSC, GSD and GSP. Trans, 6005 kc. 10:15 a.m.-5 p.m. on 11880 kc., 5:15- 6, 9 -11 p.m. on GSC, GSD and pos- CANADA 9:15 p.m. and 9:45 p.m. -12 M. on sibly GSP or GSI. 11715 kc. VE9DR, sister station of VE9DN, at (TPA4). GERMANY Drummondville, Que., has returned HICKSVILLE The latest schedule of the German to the air. It is on daily, relaying A NEW experimental station, stations is: For E. Asia, 12:30- CFCF in Montreal, from 6 a.m. -11 p.m. W2XBG at Hicksville, L.I., 3:50 a.m. on DJN and DJQ, 3:50 -7 and on Sun., from 7 a.m. -9:15 p.m. has been reported broadcasting news a.m. on DJQ, 8:05 -11 a.m. on DJN and VE9DR is on 6005 kc. also. Address reports around 7:30 p.m. on 6010 and DJE. the station in care of the Canadian 6425 kc. This station is operated by For S. Asia, 12:30 -3 a.m. on DJA, Marconi Co.

because it is our Sixth Anniversary GIFTtoYOU! This year, SHORT WAVE CRAFT celebrates its Sixth Anniversary. Annual increases in circulation. plus authentic, exclusively short- wave editorial material, makes SHORT WAVE CRAFT unquestionably the leading magazine in its field. To commemorate t° is notable occasion, the Editors have written this outstanding book. With Your 51.00 Subscription to Wave Short Wave Craft Partial Contents of Short Guide YouBa Get This Short -Wave Questions and Best Aerials for Short -Wave Y u New Answers Reception Book. for FREE It Is impossible to publish each month lu The many elaborate antennas suitable short -wave rim -I Vera often present prob- The special subscription rate la 7 SHORT W.\ 1'1.; Clt. \l'T all the questions lems for set owners. SHORT WAVE moallta for $1.00. (Regular news- (and their ausoersl sent to us. we have GUIDE will help Silo decide which aerial stand rate le $1.T:.) printed with full illustrations. In SHOUT Is best for your rereher. 'tiny tores of Send the coupon today. with your WAVE GUIDE, hundreds of Important antenna are illustrated. remittance of ()ne dollar ($1.001. questions which have been recently re- Practical Hints on Short -Wave When your subscript ton is received. ceived. Tuning a rope of our SPECIAL ANNIVER- SARY GIFT will he sent to you Hundreds of short-wave stations are heard I'OSTI'AID. - Short -Wave Kinks. Illustrated by fans -and hu:ldreds mure mold be Fiery short -wave fan is interested In heard distinctly if only Suu kutw n You do not have to be a new subscriber Meant tuning them in. Expert advice on to receioe this gift. If you sub- w kinks and shortcuts. Dozens of kinks proper tnnl,g is included in SIIOItr a reach us every week In SHORT scriber at present, copy of r"SHO rr The -and WAVE CI'IllR. WAVE will be size GUIDE" sent you upon of SHORT WAVE WAVE GUIDE you will find a variety "Police Call" Receiver and How receipt of $1.00. and oe will advauto GUIDE of them. carefully illustrated. They will > ar to Build It mr subscription by seven months. funtl edawire prone very valuable to you. ins diagrams and phoéo9raphe. Phe most stirring signals on the air are polite calls and every fan wants to hear SHORT WAVE CRAFT, 990 Hudson Street. New York. N. Y. 7 s -Wave Re- Complete you For. Simple. Efficient Short these exciting alarms. details Gentlemen: Enetov0il will amt toy remittance of ONE Dollar ta ltinul (Canada and for and a "pollee Igo 51.30) for which enter Y subscription for Sev Months tu .1101íT WAYF. ('RAF r. ceivers Which Anyone Can building operating You ae also to d bsdtdely FREE. and postpaid, a coley of the Special Anniversary Build rail" receiver will be found. Gin Seek -SHORT WAVYE. GUIDE. A Simple "Ham" Transmitter Name Complete constructional plans for build - of who want lug malty 1, 2 and 3 -tnl,e receivers will There are thouaanda fans to Address it t Here be Schematic diagrams. lists bglld simple transmitter. is the also found. ideal It ter for beginners. It IS cil state to tratsut D New Sebscriber D Old Subscriber of parts -everything you need to know pratt lea I. Net luexpenslr'e to construct. remittance or Stamps. irorclgn: build these seta and make them function List of necessary pans. wlriug diagram.. itrternufl Money Orderl1l Begirt.. letterletterr If contains cash cor stamp it properly is Included. and construction details are included.

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www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 181

What Does It Cost to Become TUNE BY EYE An Amateur? (Continued from page 179) A CW telegraph transmitter is ridiculous- equipment necessary to get "on the air," ly simple as compared to the simplest phone. the really GOOD amateur station is faced It is merely necessary to purchase or con- with some slight additional expense in construct some form of radio frequency oscilla- nection with the operation and maintenance tor capable of generating a signal at some of it. No GOOD amateur would be without lawful frequency, arranged with a method one or two of the popular "Handbooks" Now you can add a genuine RCA Cath- of breaking up the output into dots and which contain ready references and con- ode Ray Tuning Indicator to almost dashes by keying, and you're "on the air "! structional data on all types of equipment. any receiver having automatic volume There are many forms of such radio fre- He should also be a subscriber to one or RCA Kit makes your set quency oscillators. These may be of the more of the leading radio magazines. He control! This type in which the control of the frequency will be required -by law -to have a suitable like a '36 model. Easily installed. Kit, rests entirely with the operator, or the more "log" book for recording his operations. including 6E5 tube, socket, escutcheon, advanced type in which the frequency is These may be made by ruling pages in a bracket, cable, everything necessary, controlled and fixed by means of a piezo- blank book, or "log" books already ruled Stock No. 9688. electric crystal -a quartz plate -and com- and printed for the purpose, are available only $$33.00. monly referred to by amateurs as crystal from several sources for a nominal sum. control. This latter type is by far the more Once you are in operation the many ama- desirable and the "new- comer" is warned teurs with whom you converse will send / UNIVERSAL AUDIO against the self -controlled type of oscillator. you acknowledgements of your communica- While a self -controlled oscillator is capable tion in post -card form; these are popularly TRANSFORMER - of very good results in the hands of an ex- known as "QSL" cards. You must also be perienced and capable operator, they are prepared with a supply of such cards with This replacement unit couples any dangerous for a beginner; we refer to the which to return their courtesy. These may general -purpose triode such as -01 -A, in them dangerous. It is be made by hand on Government postcards legal phase calling 26, 27, 37, 55, 56, 76, 85, 6C5, to so easy to allow them to oscillate at fre- or purchased from any number of printing 30, quencies outside of an amateur band and establishments at a small cost. the grid of any class A amplifier tube, also radiate illegal notes, broad waves and If you are going in for "message han- singly or push -pull similar undesirable characteristics, that dling," suitable message blanks may be pur- Metal Case. Size they are dangerous for the new- comer. chased also, The above, together with the Therefore we suggest that you "forget the apparatus itself, comprise the "complete" 2 x 2 -3/8 x self- controlled oscillator." amateur station. We can safely say that 2 -7/8 inches The range of a low -power CW transmitter $10 will purchase all the required books, including is considerably greater than a similar power magazine subscriptions, QSL cards and sta- lugs. Stock in a phone transmitter. Also certain fre- tionery required. So we can then arrive at quency bands are open to the new -comer the grand total of about $35 to put a com- No. 9632. in amateur telegraphy, that permit greater plete "CW" radio telegraph station on the Price $2. distance being covered, than is the case in air. If necessary to build a receiver, or re- the phone bands. Thus we may expect to vamp a non -oscillating type, our total sta- better the estimated 200 mile range of a tion cost will rise to about $42.50. simple low- powered phone considerably with The equivalent radio telephone station we RCA PARTS a simple crystal oscillator of low power. have already seen, will cost at least $100. We can then use the oscillator itself, with Count the pennies in the "teapot" and go RCA Manufacturing Co.,Camden,N.J. gratifying results. Unlike phone, additional forth on a shopping expedition that will re- A Strike of the Radio Corporation of America stages beyond the oscillator are not essen- sult in giving you entry into that wonderful tial for good operation. Doublers, buffers fraternity of world -wide friendships, the and amplifiers may be added to our oscilla- amateur radio game! tor later, as we can afford it. These are an absolute necessity though, when placing a phone on the air. He Talks Through His Hat Have You Seen the "Good" Crystal Best Purchase We need only pick a suitable circuit from and Gets Paid for It among the hundreds appearing in radio pub- (Cold hilted fr.ent lmge 135) New Magazine lications and build a simple crystal oscillator with its associated power supply. Most would suspect any trickery from an ordin- important of all is the purchase of a GOOD ary- looking car parked somewhere in the crystal and holder. It is possible to buy neighborhood? 8 crystals for as little as a dollar, and holders What the invisible "Power- plant" used THE VOCATIONAL DIGES for half that, though it is questionable by Mr. Hicks looks like is shown in the whether either represent the best. economy. accompanying illustration. The "B" bat- The crystal is something that will always tery unit installed in the small box at the Telling you bow to go about: be a part of your transmitter and it is left side consisted of 30 dry -cells each better to purchase a good one, even though of 3 volts, which resembled somewhat in When You are Tackling the the cost is a bit higher. Select a crystal its appearance an elongated 14 gauge shot- Job of Finding a Job; which resonates in the lowest frequency gun shell. The right -hand box contained band that you expect to use, in order that the 6 volt "A" battery for the filament cir- When You are I'lanning a you may operate in a higher frequency band cuits of the acorn tubes. In the same Career; after you have added a doubler stage to box there was also space provided for a your outfit. Select a crystal so that the even standard small -size flash -light battery of When You Want to Better harmonics of its natural frequency fall in 1!ti volts, to energize the pocket -size mic- Your Position. the higher frequency band. For the benefit rophone. A modulator unit installed in of all concerned it is urged that your initial the box between the "A" and "B" bat- The new magazine giving >ou every month a operating be confined to the band between teries and two switches to control the bat- digest of articles from magazines and news- 1715 and 1800 kilocycles. By so doing you tery current, completed the equipment of papers all u r the ,,, untre. will avoid a great deal of interference which the "power- plant." HOW AND WHERE, TODAY would otherwise make your early efforts in The transmitter and modulator con- radio telegraphy difficult, until you pick up struction is shown in the accompanying alert, resourceful men and women have suc- the knack of reading code signals through ceeded. where others. WHO DID NOT KNOW, circuit diagram. The lower box marked have failed. heavy interference. by dashes envelopes the modulator unit, "On the Air" for $25.00! which was installed in the center of the PRESENT -DAY JOB COMPETITION IS IN- You will find that including an excellent leather belt. Experienced amateurs will TENSE. ONLY TILE INFORMED MAN OR crystal and holder. the parts for your recognize that the modulator operates ac- WOMAN CAN STAY IN THE RACE AND WIN. crystal oscillator will be in the neighbor- cording to the methods of the well -known hood of ten dollars; a similar figure will also Heising system. "JOBS & CAREERS" be needed for the power -supply. Allow an- This modulator unit was connected with YOl'lt. GUIDEBOOK OF OPPORTUNITY other $5 for the key and transmitting the "silk -hat" transmitter by means of IS antenna equipment and what few mis- two wires leading to the coils both all cellaneous switches and insulators you will marked with "4 ". These coils are used as On newsstands 25c need and you have a complete, low -powered, R.F. chokes to avoid trouble by unwanted If your dealer cannot supply you, send a legal and efficiently operating radio -tele- radiation. The tubes used quarter and tee trill forscanl a copy at once. graph transmitter for sonic twenty -five dol- were of the lars! To this may be added equipment as triode type 955. The various parts of the desired until the station eventually becomes transmitter are, as the diagram and the JOBS & CAREERS complete. dimensions indicate, of quite tiny dimen- 520 N. Michigan Avenue. Sw7, Chicago, Illinois While the above figures represent actual sions. ,I Please mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com 182 SHORT WAVE CRAFT for JULY, 1936

CISIN'S SENSATIONAL Short Wave Scouts New Magic Electronic Eye (Continued from page 149) TWO GREAT Call Freq. Sched. Location W2XE -6120 kc.- Relays WABC. Atlantic B- "TEST -ALL" cast. Corp. N.Y.C. W2XE -11830 kc.- Relays WABC. Atlantic B- TUNING INDICATOR cast, Corp. N.Y.C. W2XE -15270 kc.- Relays WABC. Atlantic B- s-w 10C cast. Corp. N.Y.C. 95 WSXAL -6060 kc.- Relays WLW. Crosley Ra- BOOKS $ dio Corp., Cincinnati, Ohio. W3XAU -6060 kc.- Relays WCAU. Newtown Square. Pa. W3XAU Relays WCAU. Newtown Complete Kit of Parts. -9590 kc.- less tubes. with (tackle Square, Pa. Finish Metal Cabinet. W3XAL -6100 kc.- Relays WJZ. Nat. Broad - Aluminum Shield. Dla- casting Co.. Bound Brook, N.J. Pm. P,ndine U. S. grant and net :11101 In- &Hof No. so2.586 W3XAL -17780 kc.- Relays WJZ. Nat. Broad- atructions. casting Co.. Bound Brook, N.J. NEWEST SHORT WAVE ACCESSORY! W9XF -6100 kc.- Relays WENR. Nat. Broad- Tunes in those Elusive 8.W. and Foreign Stations. casting Co., Chicago, Ill. Tests Power Packs. Audio Distortion. Antenna Sys- W9XAA -6080 kc.- Relays WCFL. Chicago Fed. tems. Locates Opens, Shorts. Leakages. Lines up r.f. Labor, and t.t. stases. Measures halted y. a.c. and d.c. volt- Chicago, Ill. ages. Measures and compares resistances and capaci- W4XB -6040 kc.- Relays WIOD. Miami Beach, ties. Self -contained a.c. -d.c. power supply. Fla. EASY TO BUILD -EASY TO USE W1XAL -6040 kc. -World Wide Broadcasting Each book contains Kit of Matched Tubes II Metal Tubes, 1 Magic Corp., Univ. Club, Boston, Mass. 32 pages and num- Kyel $3.05 WIXAL -11790 kc. -World Wide Broadcasting erous Illustration,. H. G. CISIN, Chief Engineer Corp.. Univ. Club. Boston, Mass. Over 15,000 words ALLIED ENGINEERING INSTITUTE WRXK -6140 kc.- Relays KDKA. West. Electric in each book. Dept S-2S, a Park Piaui, Now York, N. Y. & Mfg. Co., Pittsburgh, Pa. WRXK -11870 ke.- Relays KDKA. West. Electric MAKE FOUR DOERLE & Mfg. Co., Pittsburgh, Pa. HOW TO WRXK -15210 kc.- Relays KDKA. West. Electric SHORT WAVE SETS SPORTS BINOCULAR & Mfg. Co.. Pittsburgh, Pa. 1TF:RALI.Y thousands of radio fans have built the' W8XK *r1 famous DOERLE Short Wave Radio Receivers. So A real high -power field -21540 kc.- Relaya KDKA. West. Electric Insistent has been the demand for these receivers. as glass that enables you to & Mfg. Co.. Pittsburgh. Pa. well as construction details. that this book has been enjoy such sporting events CANADA *aneelally published. as Baseball, Boat Races, Contains EVERYTHING that has ever been printed on CJRO -6150 kc. -6 -12 p.m. Jas. Richardson & these famous receivers. Three are the famous seta that Horse Races, etc. Most Sons, Winnipeg, Manitoba, Can. appeared in the following issues of SHORT WAVE useful on Auto Trips, CJRX -11720 kc. -6 -12 p.m. Jas. Richardson & CRAFT: "A 2-Tube Receiver that Readies the 12.500 Hunting, Sons. Winnipeg. Nile Mark," by Walter C. Doerle (Dec.. 1931 -Jan.. Outings, Manitoba. Can. 1932). "A 3 -Tube 'Signal Gripper.' ' by Walter C. Beaches, etc. It's a real VE9DN -6005 kc. -11:30 p.m. Saturdays. Ca- Doerle (November 1932). "lloerie '2- Toler' Adapted buy at a fraction of its nadian Marconi Co., Montreal, Quebec, Can. to A. C. Operation' (July 1933). "The Doerle 3 -Tube worth. *Signal- Gripper' Electrified." (August 19331 and "The MEXICO Doerle (toes Rand -Spread' " (May. 193M. PARCEL XEBT-6000 kc. a.m.-1 a.m. El Buen Tono, Due to a special arrangement with SHORT WAVE long, extends to -8 CRAFT. we present a complete 32 -page lank with still POST $150 6W. Lenses nearly tao Mexico. D.F. (3 blasts on horn) covers, on an extra grade printed heavy of paperper with PREPAID inches in diameter. Black *numerous Illustrations. Nothing has been leftout. Not crackle finish. Carping PANAMA only are all the DOERLE sets In this book. but an strap. excellent lowier park if rou wish to any HP5B -6030 kc. -12 n.-1 p.m. and 8 -10:30 p.m. electrify of the Money back guarantee. You can't lose! "Estacion Miramar," P.O. Box 910, Panama. DOERLE sets. is also desrribed. HP5J -9590 kc. -11:30 a.m.-1 p.m. and 7 -10 p.m. HOW TO MAKE THE MOST POPULAR "La Voz de Panama," Panama. Rep. of Pana- ALL -WAVE 1- and 2 -TUBE RECEIVERS GOLD SHIELD PRODUCTS CORP. ma. 17 West 60th St. Dept. S. New York City *'THERE has been a continuous demand right along ,.. CUBA 1 for a low-priced book for the radio perintenta, radio fan, radio Service Man, eke., who wishes to build COCH -9428 kc. -8 a.m. -12 p.m. General 1- and 2 -tube all -wave sets powerful enough to oper- &BACK NUMBERS Broadcasting Co.. Havana. Cuba. ate a loudspeaker. COCD-6130 kc. -11 a.m. -12 n. and 7 -10 p.m. This hook contains a number of excellent sets, some SHORT WAVE "La Voz del Aire," Havana. Cuba. of w /itch (case appeared in past lames of RADIO - kc. a.m.-1 CItAFT. These sets are not toys hut have been care- CRAFT COCO-6010 -9:30 p.m. and 7 -10 p.m. fully engineered. They are not experiments. To men - P.O. Box 98, Havana, Cuba. MAILED PREPAID tion only a few of the sets the following will give you 70c an Idea. CENTRAL AMERICA s* For a limited time only, and as long as The Megadyne 1 -Tube Pentode Loudspeaker Set, by they last, we will send you six back num- Ti -RCC -6550 kc. -6-7 p.m. Radioemisora Cato - lineo Oernaback. a Electrifying The ilegadyne. bers of SHORT WAVE CRAFT assorted, lica Costarricense, San Jose. Costa Rica. How To Make a 1 -Tube Loud- speaker Set, by W. TG2X -5940 kc. -11 p.m. "La Voz *P. Chesney. How To Make a Simple I -Tube MI. your choice, for 70 cents. -9 de la Po- Wave Electric Set. by F. W. Harris if How To Build The usual price for six copies would be licia Nacional," Guatemala City, Guatemala. A Four -In -Two All-Wave Electric Set. by J. T. $1.50 and most publishers charge a higher SOUTH AMERICA Beesley. and others. price for back numbers over one year old. Not only are all of these sets described in this hook, We can supply ostia the following YVIORSC -5720 kc. -6 -11:30 p.m. "La Voz de plk but It contains all of the illustrations. hookups. etc. - back numbers: Dec. 1930; Feb., April., Tachira," San Cristobal, Venez. And believe it or not. each book Contains over 15,000 June. Oct. 1991; Sept. 1932; Sept.. Nov., YVI2RM -6300 kc. -8-11 p.m. "Emisora 24 de p rds of new leg lido type. Each honk is thoroughly Dec. 1933; Jan.. Feb.. Mar., April, May, Julio," Maracay. Venez. *Modern and up -to -date. All the latest Improvements June, July, Aug., Sept., Oct.. 1934; YV6RV -6520 kc. -11 a.m. till 2 p.m. and 5.10 hace been incorporated Into the sets. 1935 issues; 1936 issues to a.m. "La Voz de Carobobo," Valencia. Venez. Remember. these banks sell at the extraordinary low -All -All Price of ten cents; you ran not possibly go wrong In date. YV3RC -6150 kc. -11 a.m. till 2 p.m. and buying them. Despite its lop' coat. our usual guaran- If you do not specify copies we will use 4 -10:30 p.m. "Radiodifusora Venezuela," Cara- tre goes with this book as well! our own judgment in sending assorted cas, Venez. IF TOT' DO NOT THINK THAT THESE ROOKS numbers to fill your order. Note we can- HJ3ABH -6010 kc. -11:30 a.m. till 2 p.m. and ARE WORTH TILE MONEY ASKED FOR THEM not exchange the copies for ones that 6 -11 p.m. "La Voz de la Victor," Bogota. RETURN THEM WITHIN TWENTY- FOt'It HOURS have been sent to you. Colombia. 4ND Torn MONEY WILL ItE INSTANTLY 101 Practically copy of SHORT H.I4ABC -6451 kc. -7 -10 p.m. "Ecos del Com- FUNDED. WAVE CRAFT contains important in- beima." Ibague, Colombia. There has never been such a formation that should have. is HJ1ABE -6115 kc. -9 "La Voz de la wealth of data published in you Here 7:30 p.m. low -priced radio hooks of this a chance to get those copies. Laboratorios Fuentes." Cartagena, Colombia. type in the history of the radio As we have only a small supply of back HJIABG -6042 ke. -12 -1 p.m. and 6.10:30 p.m. publishing business. numbers on hand, this offer will be with- "Emisora Atlantico," Barranquilla. Col. Take advantage of the special drawn as soon as they have been sold. HC2RL -6660 kc. -5:45 -7:45 p.m. Sundays and offer we- making and use the We accept U.S. stamps. U.S. coin, or 9:15 -11:15 p.m. Tuesdays. Quinta Piedad, coupon below. money order. Rush your order today. Guayaquil, Ecuador. RADIO PUBLICATIONS CEC -10670 kc. -7 -S p.m. Comp. Internacional 101 Hudson Street SHORT WAVE CRAFT de Radio, S.A. Santiago Chile. New York, N. Y. 99 -101 Hudson Street New York, N. Y. OAX4D -5780 kc. -Mon: Wed. -Sat. 9 -11:30 p.m. All America Cables. Lima. Peru. OAX4G -6230 kc. -7 -10 p.m. Roberto Grellaud RADIO PUBLICATIONS SW -7 -36 SHORT WAVE CRAFT 7 -36 & Cia, Lima. Peru. 101 Hudson Street 99 -101 Hudson Street. New York. N. Y. DOMINICAN REPUBLIC New Yark. N. Y. Please send immediately hooka checked: Gentlemen: I enclose herewith 70e. far which you HIH -6814 kc.- 12:15 -2 p.m. and 5:30 -9 p.m. lioe to Build Four Doerle Short -Wave Sets...... _...10o "La Voz de Higuamo," San Pedro de Macona, (lote to Make the Most Popular All -Wave 1- and are to send me six back number copies of SHORT Dom. Rp. 2 -Tube Receivers loo HIX -5980 kc.- 4:40 -5:40 p.m. Estacion Radio- I am enclosing c; the price of each hook sa 10c. difusora. HIX, Ciudad Trujillo. Dom. Rep. (Coin or U.S. Stamps acceptable.) Books are sent post- WAVE CRAFT as follows HIZ -6316 kc.- 5:30 -9 p.m. Estacion Radiodifu- paid. sore. HIZ, Ciudad Trujillo. Dorn. Rep. Hama - EUROPE Name EAQ ..._ ...._...._...._.__..._.._._.._- -9860 kc. -5:15 -9:30 p.m. Transradio Address Espanola. Madrid. Spain. Address - HAS -3 -15370 kc. -Sun. 9 -10 a.m. Radiolabor. City Budapest. Hungary. City..._...... _..__ _.._.._. »..._. ».._.__._._____._ State..._..__...._._ Please mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 183

HAT -4 -9125 kc. -Sun. 6 -7 p.m. Radiolabor, Bu- dapest. Hungary. PHI -11730 kc.-8:30 -11 a.m. except Tuesday and Wed. Philip's Radto- Huizen, Holland. New ! PCJ -15220 kc. -(See card.) Philip's Radio, New ! Eindhoven, Holland. 15245 kc. -7 -11 a.m. Station Radio Colonial, Parie, Franca kc. 11 a.m. 6 10e BOOKS GREATEST 11880 -4 -5 a.m. and till p.m. Station Radio Colonial, Paris, France. 11715 kc.- 6:15 -9 p.m. and 11 p.m. till 1 a.m. Station Radio Colonial, Pari, France. ORK -10330 kc.- 2:30 -4 p.m Radio Ruysselede. Brussels, Belgium. 2R0-3--9635 kc. -(See card.) E.I.A.R., Rome, Italy. GERNSBACK EDUCATIONAL LIBRARY N4 3 2R0 -4 -11810 kc. -10:15 a.m. till 12:30 p.m. and 1:30 -2:30 p.m. E.I.A.R., Rome, Italy. DJC -6020 kc. -11:35 a.m. till 4:35 p.m. and 4:55 -10:45 p.m. Deutscher Kurzwellensender. ffl?ERNITIJYG Berlin, Germany. DJN -9540 kc.- 12:30 -3 and 3:50 -11 a.m. and 4:55 -10:45 p.m. Deutscher Kurzwellensender, CURRENT Berlin. Germany. DJI -9675 kc. -5 -7 p.m. (now DZA). Deutscher FOR BEGINNERS Kurzwellensender. Berlin, Germany. DIQ -10290 kc.- Irregular (now DZC). Deut- DESIGN scher Kurzwellensender, Berlin, Germany. How dXPERawns DJD -11770 kc. -11:35 a.m. till 4:35 p.m. and GENERATORS INSTALLATION 4:55 -10:45 p.m. Deutscher Kurzwellensender, MOTORS DOUBLETS Berlin, Germany. OHM'S LAW -11 Deutscher Kurz- DOUBLE DOUBLETS DJB-15200 kc.- 3:50 a.m. NOUN WIRNG SYSTEMS wellensender, Berlin, Germany. APPLIANCES INVERTED "Lh DJE-17760 kc.- 8:05 -11 a.m. Deutscher Kurz- `TRANSFORMERS TRANSMISSION wellensender, Berlin, Germany. HVJ -15120 kc. -10:30 -10:45 a.m. Radio Vati - I, INDUCTANCES LINES cano, Vatican City, Rome, Italy. A.C. INSTRUMENTS AUSTRALIA VK2ME -9590 kc.-1 -3, 5 -9, 9:30 -11:30 a.m. Sun. "Voice of Australia," Sydney, N.S.W.. Australia. VK3ME -9510 kc. -4 -7 a.m., except Sunday. Mel- bourne. Victoria, Australia. 3LR -9580 kc. -3:15 7:30 a.m. except Sunday. RAD10 PUBLICATIONS. WI HUDSON St. NLIEYDAI.IIY. Nat. Broadcasting Service, Lyndhurst, Vic- `RADIO PUBLICATIONS, 101 ON ST.NEWIDNK,N.Y toria, Australia. ITEItAI.1.Y thousands of beginners each y( ar been we recent months the mdlo public has k the question 'HOW CAN 1 GET I. made aerial- ron.V Nnns by virtue of the many STARTED IN RADIO?" Jr order to under on articles and adsert lsements Aerial Fquip- elan 1 the theory of radio. It is necessary. first meni which have appeared in many radio nlaga- of a I. to hare a fundamental knowledge of eler- sines and literature. These articles have been leif ty and. particularly of alternating currents. so diversified. and In many eases so conflicting. We stress this point because radio is a study of that the tadin experimenter. fan and Service alte rating current, of a very high frequency Man are beginning to scratch their heads and not re. ask: "plays It all about t" As a nse. II this book, which is prepared especially for quenre. the demand for low- grind honk e rew beginners. we ex dalti In a simple, lurid plalnitlg in a clear. Meld manner the principles man ter: How Alternating Current Is Generated: underlying the design and Installation of effi- Wh t Its Properties Are; What The Laws Gov- cient aerials has become a crying nerd. Fur- erni y It Are. and How It Is Applied To Every- thermore. the steadily Increasing nuisance of day Household Use. Furthermore. o give In man -made statue, esttt ing In noisy radio re- slut le language detailed inns urtionsonyy how to reptian- pa rt irularly in connection with short- with alternating wave rereivers-has made the Imtortanre of a currpert tit ióac t cal experiments goal antenna a paramount issue. For the thou ALTERNATING CURRENT FOR BEGINNERS ands of radio fans. both short-wave and broad- 'rl is book contains even-thing necessary to rest. who wish to know lust what type of an- give the beginner his first foothold in the studs tenna they should use and why, this honk has of e eetrioliy and Radio. Electric circuits arc been especially published. expl [fled with simple analogies to hydraulic 'vol tile. Ohm's Law, one of the fundamental ALL ABOUT AERIALS Lose Of radii, to thoroughly eailla Ined; the gro- In simple. understandable language this book etat on of alternating current ; sine x ; th, explains the theory underlying the various types nit -volts. amperes. and watts are explained. of aerials: the Inverted the Doublet, the Condensers. transformers. A.C. Instruments. nm- "L." b rs and these are eta. It how noise -free generators-all thoroughly Double Doublet. explains disc used. Ilntse- wiring systems, electrical an- reception can be obtained. how low -impedance tulle lres and electric lamps- nothing has been transmission lines work: why transposed lead - left out. ins are used. It goes into detail on the ron- H re are some of the practical experiments nirwrtion of aerials suitable for long -wave which you can perform at home. Simple tests broadcast receivers. for eilon -wave receivers. and for Iiferentialing bruin ern alternating and di- for all -wave receivers. The book Is profusely ect current: how to light a lamp by induct iii,. how a simple electric how de- Illustrated in a manner which will appeal to the to make horn; to Meg etice o watch; how to test motor arma- most inexperienced in radio; clear, self- explana- ture : how to charge storage batteries front A.C. Is In so simple a style that It tory: it written o u0 t ; how to test rnmlensers with A.C.; how tl. will clear up the aerial situation In your mind. mak A.C. electro magnets; how to fry eggs on once and for all. Such a wealth of Information a cake of lee: how to make simple A.C. motors Is presented in this hook that you will wonder and many others. how it rail be done at this low price. Harold E. Bissell, J r., Of Tonii Road, TI e book mulleins 32 pages. profusely Illus. Oat d with clear. self -explanatory diagrams. It Believe it or nat. the book eontains over 15.- Stamford, Conn., this month's "Trophy runt ins over 15.000 words of Near. legible Ilia. 000 words of clear. legible type. It is thorough- Winner" and the receiver that clinched It is an education In Itself and lays the gmuud ly modern and up-to -date. the Trophy for Mr. Bissell -a 16 -tube cork for a complete study of radio and electri- Remember that this book sells at the extra- -wave set. ity. ordinary low price of 10e; you eannot possibly MIDWEST all A the extraordhtag price of IOC, you cannot Doss lily gn wrong. Despite tow go wrong in buying it. Despite its low Cost, its cost. tam- usual guarantee gue> with Ohi. b",k. our usual guarantee goes wits this book. en IF YOU DO NOT THINK THAT IF YOU DO NOT THINK THAT THIS BOOK IS WORTH THE MONEY THIS BOOK IS WORTH THE MONEY Before You Submit ASKED FOR IT. RETURN IT WITHIN ASKED FOR IT, RETURN IT WITH Read This 24 HOURS AND YOUR MONEY WILL BE INSTANTLY REFUNDED. BE ISNTYORDWILL ED. "Veri" Cards! NTALEF has a There has never been such a There never been such Many listeners submit cards for the "Trophy wealth of data published in a y in a wealth of data published low- radio book at this Contest" which do NOT specifically verify re- priced radio book of this low - priced type in the history of the radio price in the history of radio bus- The form of these cards is: ception. general publication business. Take ad- n....., adyaniage of this acknowledge receipt of your reception re- "We o tine of this special oflrr we n. r ue making and you very !l below. port of date. Thank much." art caking and use the coupon This is NOT a verification! below. RADIO PUBLICATIONS Unless the card specifically says: "We VERI- RADIO PUBLICATIONS 101 Hudson Street FY your reception of date," or. "Your 101 Hudson Street New York, N. Y. report of date is correct." the card is New York, N. Y. NOT considered as a "verification" for this con- MI= ==--- = - - - -- test. 4)- SW -7 -3(i So. be sure that all cards submitted really are PUBLICATIONS (No. 3) SW -7 -36 RADIO PUBLICATIONS (No. RADIO 101 Hudson Street "verify eat inns. " -Ed Her 101 Hudson Street New York. N. Y. New York, N. Y. Please send immediately your book "ALL ABORT Please send immediately your book "ALTT7tNATlNG AERRIAL.S." for which I encline 10e tanin or It. 8. stamps. CURRENT FOR THE ISFGINNF:11." for which I enclose acceptable). ]took Is to be sent prepaid to me. 10e (coin or 1-. S. stamps acceptable ). Book is to be lent The August issue will contain ar- prepaid to me.

Name . ticles which you can't afford to Anten- Name Adehesr miss, on such subjects as- Address nas, 5- meter- Sets and S -W Broad- City State cast Receivers. City State Please mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com 184 SHORT WAVE CRAFT for JULY, 1936 Cut Prices on Many Popular Radio Books IMPORTANT-The 25 hooks listed are :U.l. different ones from those listed in last month's ad. THE RADIO AMATEUR'S PHOTOCELLS AND THEIR AP- HANDBOOK. 'New Revised Edi- PLICATION. !Second We herewith present a selected collection of recent important radio Edition.. V. Zworykin HOW TO ORDER books. We have. alter an exhaustive study, selected these volumes tion), by A. Frederick Collina. by K. and E. D. Wilson. Cloth covers. sise 5 aIS" because they represent the foremost radio books of their kind in Cloth covers, else 5%s1% ", 394 We cannot ship C.O.D. Our 110 332 180 illustra- print today. There is such a great variety that we are sure It will pages. Illustrations. $1.87 pages. $2. 88 prices are net. as shown. Some Price I inns. Price as,PLL.. 0000 satisfy any taste as well as any requirement that the student of of the books sent prepaid (in radio might have. If you with to become radio Does this book tell you why and U. S. only). Those that are Wo publish no catalog and ask you to be kind enough to order amateur (radio ham) this book how to use light-sensitive cell.? not thus listed will be shipped direct from this page. Prompt shipments will be made to you tells you how. Everything In re- The answer to that the first edi- by express collect if sufficient direct from the publishers. We merely act as a clearing house for relying and transmitter sets and tion s "sell out. ' and the postage is not included by you. a number of radio publishers and OUR PRICES ARE AS LOW OR how to build them. second sedition. brought right up LOWER THAN WILL BE FOUND ANYWHERE. Remit by to date. Is even a better volume. money order or certified cheek. Register all letters containing cash. Enough said. RADIO THEORY AND OPERAT- NEW LOW PRICED SHORT WAVES, by C. R. Lents OFFICIAL SHORT -WAVE ING, by M. T. Loomis, 5th re- and lt. B. Gable. Stiff Covers. RADIO MANUAL. Volume I. by vised Edition. Cloth- bound; Mee ELECTRONICS. by R. C. Hud- RADIO BOOKS sire gab ". 384 pages, 258 Illus- Hugo Gernsback and H. W. Seem, 5u4s8at 4" thick; 1.000 pages; son. Cloth cover., size 619 ", 131 trations. Pelee was formerly $2.98. with 352 pages. Illustrations. Flez- over 300 se.lu; 450 review quw- 45 ilWstratIon,. are 12 new. up-to -date look NEWIaRICE NOW. Ible, Looseleaf Leatherette Binder. Price iero i l e a . and answrrs. $1.88 y mates. is ame radio subject. $100 Sire 9z12. Price Price $4.38 n )'repaid $2.00 This book is written for the ost published. Modern In m ry The biggest and most complete Written In textbook style, tre- reader who may wish to know use. .'eLL 110l1CA UNDID( book 011 short naves. Covers every mendous amount of useful something shout what is going on veut 61 to 72 pages; 50 to 120 including S. W. The one and only short -wave manual infor- imaginable phase, mation hat been trammed into and who has not heretofore given !lust ratinas. Ail looks written b Superheterodynes. Television. Air- published. Contains constructional the matter murk attention." says cell -knee") radio authors. Orale craft Radio. Ultra Short Waves. Information on the most important this thin-paper, compact reference the work. Radio tranemiesion and re- author. Head It and learn by Nmnler. Directional Antennae, etc. The Short-Wave Receivers. sections on how dry rectifiers, vacuum tubes. No. I RADIO SET ANALYZERS authors are famous short -wave S.W. Transmitters. filtra Short ception have been covered, "from batteries, television tubes, 'evates, soup to A book. and No. 2 MODERN RADIO VACU suthorltles. This is the best book S.W. Beginner's section. nuts. truly great o'her apparatus. work: get the UM TUBES en Sheet -Waves in print today. 1l winding. AC. -SW. Poorer "low down" on electrons and atom.. No. 3THE SUPERHETERO Parks. kinks. etc., for S.W. Ex- DYNE BOOK perimenters, entions on S.W. Con- certera. MODERN RADIO ESSENTIALS. No. I MODERN RADIO HOOK PRACTICAL TELEVISION, by Antennae, Superhetern- UPS. by R. It Washbunm E. T. Larner. Cloth covers, else dynes, Amateur ['hone Transmit- by Kenneth A. IIall,away. Cloth covers, sire 81,485% ", over 200 SHORT WAVE RADIO HAND No. 5 HOW TO BECOME A RA 114z$% ", 333 pages, ter,. Super Regeneration in S.W. BOOK, by Clifford E. Denton. MAN d.á.69 Receivers, S.W. Therapy, S.W. pages. and over 100 DIO SERVICE 12T illustrations. Pries s illustrations. l'rlce $1.95 Paper covers, size 61/4s81/4". 128 No. 6 BRINGING ELECTRIC Physics, etc. pages, 150 illustrations. $1.00 (RADIO) SETS UP TO This book ...plains televbton In NEW! Unlike most books dealing elementary - Price DATE. by C. E. Denton full. including aria ss radio fundamentals. Baths- h Coll No. 7 RADIO KINKS & WRIN- Iplee. photo- electric cells. and all ,' a! ' new hook Is arranged for data. elnult data, testing lets data. K LES I for Experimenters Important types of televielen quick use by the prartiral techni- R.F. nd A.F. amplifier data as well as basic principles of op- -In fart, alet us say, 'data of No. 8 RADIO QUESTIONS & cian. In addition. It hrings the ANSWERS. by It. D. tics, Image., mlrrore, lintel, etc. RADIO PHYSICS COURSE (2114 nadar right up-to -date on essent- every Imaginable sort -In connec- enlarged edition). by Alfred A. ial radio theory. tion with short -wave radio recep- Washbuneo (Oilseed'. Cloth rovers. size 7 tim." No. 9 AUTOMOBILE RADIO B SERVICING ELEMENTS OF RADIO COM- 9112 penes, 510 lllusl ratlnes. numerous tables. No. 10 HOME RECORDING MUNICATION ( Seond Edition). $3.89 ANO ALL ABOUT IT. by John IL alorecroft. Cloth cov- hitr V FOUNDATIONS OF RADIO, by Rudolph PRINCIPLES OF RADIO, by Geo. J. Saliba en, sise 6 z 91 ", 286 traces. L. Ihmran. Cloth movers by The sire ..4x8'. 246 145 Illus- Keith Denney, Pb. A. Cloth rever.. No. 11 POINT -TO -POINT RE- 341 illustrations finest and most popular )sack pages. SISTANCE MEASURE- Price $2.98 en electricity and radio. Each I rat b)IS. Numerous $247 Hsu pages. subject is clearly dismissed, with tables. Iiee 306 illustration.. Price $3.46 MENTS by C. E. Denton An Introductory volume, written No. 12 PUBLIC ADDRESS IN- the aid of dorm. of excellent This textbook gives you the funds- A marvelously written tertbook In easily understandable Byte. to drawings. Chapters on talkies. ION A N D mentale of electricity as molted with the latest radio prineiplee SERVICE the more comprehenstve, 'Tsrin- television, elevodas and service to radio. It equips you Including citele. of for further screen grid and pen- l'IGCFI PREPAID Radio Communication." work. rte. iticeesl buy In radin. study In the geld of radio. tode. amplifiers, etc. $ I -Atli souk e45 RADIO PUBLICATIONS, 97 HUDSON ST., NEW YORK, N. Y. EVERYDAY SCIENCE 5 and 10 Meter Crystal Transmitter AND MECHANICS (Contitntcd frac). page 145) Is internationally popular measuring the plate current of all three age to the first 802 and to one side of the for its many Nelentifir and stages and the grid current of the last amplifier switch. The last operation is to stage. These jacks are located along the turn SW3 on and adjust the final stage. teehniral artirleN- lower edge of the panel and a plug is used Then, for turning the transmitter on and to switch the two meters from one jack off, during communication, it is only neces- to another. sary to operate switch SW1, and all three stages may be turned on and off simul- SCIENCE Capacity Across Cathode Coil Kept EYE,RYDAYAND :MECHANICS taneously. is the finest scientific - High! technical - mechanical - With a Power Supply construction magazine In tritet oscillator it is necessary to the field. lip-to- the -min- keep the capacity across the cathode coil The power supply consists of a heavy - ute with news flashes of relatively high, in order that low crystal duty transformer with a rating of 465 scientific events. Dozens current will be maintained. The capacity volts each side of With of constructional art orles center. the con- and mati' popular experi- here should be at least 140 mmf. The coil denser input arrangement and the use of ments. Ideas from which is designed so that the condenser plates are the 83V rectifier tube, the output voltage you ran make things to seal. nearly all the way in. The other circuits, under full load of the transmitter during Edited by i.e., the plate circuits of the amplifier operation is 500 volts. The power supply stages and oscillator plate circuits, are de- should be capable of delivering at least 150 HUGO GERNSBACK signed for very low C. Of course, on 10 ma. Two 8 mf, electrolytic condensers are A Host of Interesting meters there is more than sufficient exci- connected in series to form 4 mf. on each Subjects Covered tation for the last 802, but when the final side of the filter choke. The voltage is Over 150 illustrations Wcsm'orklns - Photogra- amplifier is operated on 5 meters and the slightly too high to permit the use of a phy -Magic- l'atrnts and Inventions -Book Reviews-Metal-Working-Chemistry- first 802 is a frequency doubler, there is single condenser, because when the trans- Eon Imo ring- 51leroscOI,y - -Elect rical 1:smelnnants -1 lolse- just sufficient excitation to provide a good mitter plate circuits are open, the voltage hold Helps-Astronomy-Prise Contests -and other subjectg. plate efficiency. When we say plate effi- rises to a point where the condensers will ciency, we really mean it- because meas- break down. 1 OC the Everyday Science and Mechanics urements have shown an efficiency of nearly In the final amplifier we modulate both copy 99 -C Hudson St. 50 per cent in the plate circuit of the final the plate and screen on the power supply (On all newsstands/ New York, N. Y. amplifier. side of the screen voltage -dropping resist- The layout of the transmitter is identi- or. A modulator capable of supplying cal to the drawing; the stages follow each 20 watts of audio should be entirely satis- other according to their functions. The factory. The transmitter is straight for- rear view of the transmitter clearly shows ward in so far as adjustment is concerned, how the parts are placed, and the tube on and no "tricks" are necessary in order to WOMAN'S the extreme right is the amplifier tube, maintain efficient and stable operation. The while the small tube, of course, is the 6C6 excitation or grid tap for the final 802 is oscillator. The switching arrangement is not connected directly to the plate side of progressive; with all three switches in the the coil. Two or three turns in from the DIGEST off position we can on plate will give results. Some OPENS A NEW ERA IN WOMEN'S MADAZINES.Tt presents today's turn the oscillator satisfactory problem. for m.iaerimÿr unu.nal naa"...,..fl° .ion :bidet hum,. aññe:'p by SW1. This applies voltage to one side experimentation will be necessary here, be- ":...1. "in 1,. I...1 tertli,,,..,t...a nformamn. of SW2, which is the buffer or doubler plate cause the position which gives optimum Send IOe for sample eopy or S1.00 for the next 5 Issue& Sold at bettor newsstands, switch. After the oscillator is properly efficiency will depend a lot upon the par- WOMAN'S DIGEST. 99 -SW Hudson St.. New York City tuned, SW2 is turned on, this applies volt- ticular tubes in use and also the arrange- Please mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 1,55 ment of the circuit. When operated on 10 1 -50 inmf. variable condenser. National. meters, the final amplifier plate current 2-split stator condensers, 50 mmf. per section, is National. (off resonance condition) approximately 11-.001 mf. mica condensers. 1,000 volt, Cornell - 80 ma., and at resonance will drop down to Dubilier. IIITRTIC about 10 ma. For 5 -meter operation, the 3 -100 mmf. mica condensers, 1,000 volt, Cor- off resonance plate current of the amplifier nell- Dubilier. with the particular set described, was '75, 4 -8 mf. 500 -volt electrolytic condensers, Cor- at resonance was nell-Dubilier. while the plate current 1- 50.000 ohm resistor. 20 watts, Electrad. slightly over 20 ma. 3-50.000 ohm resistors, 60 watt, Electrad. The antenna coupling arrangement will 1 -3.000 ohm resistor, 50 watts, Electrad. depend entirely upon the antenna system 1- 25,000 ohm 50 watt resistor. Electrad. used with this transmitter. Any of the 4 -2.5 mh. R.F. chokes, National. 1 -5 prong isolantite socket. National. matched impedance type antenna or tuned 2 -7 prong (large) isolantite socket, National. feeder type may be coupled through a small 4 -closed circuit jacks, I.C.A. coil. Direct coupling is not recommended, 4-toggle switches. T.C.A. unless the antenna is a single -wire feed 1 -power transformer, Thordarson. 1 -150 ma., 20 henry (approx.) filter choke, affair. Thordarson. Complete data on the coils will be found 1 -20 -meter crystal. Bliley. in the coil table. As for results, this trans- 1-6C6. R.C.A. Radiotron. mitter gave excellent performance on both 2- 802's, R.C.A. Radintron. 5 and 10 meters and proved, especially on 1 -83V, R.C.A. Radiotron. 1 -50 ma. meter (small). Triplett. 5 meters, a crystal- controlled carrier -0 that 1 -0 -100 ma. meter (small), Triplett. or any really stable carrier, produces a 3 -4" dials. Crowe. better all- around signal for any given 1- 10x17x3" eleetralloy chassis, I.C.A. amount of input. With a transmitter of 1-10 1_. x19x t/" crackel- finished electralloy panel, this type, the power is concentrated in one I.C.A. narrow band of frequencies where on a 2 -phone plugs. I.C.A. transmitter having a considerable degree of 1- crystal microphone, Astatic. our frequency modulation we are spreading Coil Data For 5 -10 Transmitter carrier over a wide band and results, of 5 AND 10 METER course, are poor reception. On 10 meters LI -6 turns, 1'4" diameter. it is absolutely necessary that a transmitter L2 -5 turns. 1 ? ' diameter. 7 5 meters. TRANSMITTERS be controlled. While this trans- L3 -10 meters. turns l'Y' diameter. crystal- 4 turns " diameter. mitter does not have the power output L4 -10 meters, 8 turns 1,3" diameter. 5 meters, which can be compared with larger types, 4 turns 1" diameter. Use the ASTATIC it is entirely possible to "work" the entire Note:-All coils are wound with 12 tinned world with it, under favorable conditions. copper wire. L2. 3, and 4 are spaced to a length of 1 ?á ". Ll is spaced the diameter of D -104 Parts List For 5 -10 Transmitter the wire. L5 will depend entirely upon the type of antenna used. 1 -140 mmf. variable condenser, National. Crystal Microphone for QUALITY

See Your Jobber and The 804 Power Oscillator Ask the Ham Who Ones One (Continued from page 137) MICROPHONE LABORATORY, Inc. or arrangements should efficiency and there is no reason for ex- ASTATIC and plate circuits O., U. S. A. be made to facilitate the measurement ceeding them. Dept. SW., YOUNGSTOWN, of the screen and plate currents at any particular moment. It is always ad- Parts List for 804 Oscillator visable, of course, to incorporate the meters 2 -250 mmf. condensers, National, T.M.S. Westinghouse directly in the circuit, especially in an oscil- 1- grooved coil form 2'4" in diameter. 26 lator of this type, in order that the current turns. National XR -10 may be checked constantly. This oscillator, 6 -.001 mf. mica condensers, 1 -2,500 W.V., Power Generator Manufactured for U. S. Signal Corp. as was the 830 -B amplifier, is mounted on a 4 -1,000 W.V., Cornell -Dubilier 7%" x 17" x l' board which has been given 1- 10.000 ohm 25 -watt resistor. I.R.C. 200 Watt 110 V. AC a coating of black paint in order to improve 1- 30.000 ohm 75 -watt resistor, I.R.C. (with its appearance. Of course, a metal base or 1 slider) chassis may be used should the builder de- 1 -2.5 mh. R.F.C.. National sire to go to the extra expense. 2 -5 prong isolantite socket, National 1- Single -pole double-throw midget switch, How to Mount Power Tube I.C.A. 1 -0.50 ma. meter. Triplett two condensers and the coil forni are The 1 -0 -150 ma. meter. Triplett mounted on stand -off insulators in order to board, re- 1- quartz crystal, Bliley prevent any leakage through the stand -off insulators, GS -5 membering that occasionally wood may 8- National The 1 -804 pentode R.C.A. Radiotron prove to be a very poor R.F. insulator. type knobs. Crowe tube is mounted horizontally, as can be seen 2- pointer 1 -base board 7 ?1 x 17 x 1" (paìnt,d black) in the hotograph. The base support consists of an aluminum angle- bracket which holds the socket and to which are connected POWER the screen and suppressor by -pass con- S A. C. ELECTRICAL densers. This metal plate is connected to World -Wide -W from a Windmill. from available Waterpower. from your Automobile, from your Motorcycle, front your Bicycle. Foot the ground support or B negative. In order pedals or Handerank (for transi' Matte Radio Transmitters. to the other end of the tube, we Review Smog Floodlights. At, en'sing Signs): do you want to support light system,: have a small block of wood, ( Continued front pope operate AC Radio sets from 32 V. PC farm constructed 147) operate two generators In serles to get 200 V AC; obtain which has been slightly rounded out at the AC. etc.. etc. understand the principle of operation. two phase and three phase top. The tube merely lies on this wooden There Are Over 25 Applications support. Do not attempt to support the tube It is stated by the writer, W. P. Cargill (C5LR) that the unit will operate quite Some of which are: by the plate cap, and also do not make a A.C. Dynamo lighting from eight to ten 20 Watt 110 rigid mechanical connection to this cap; the well on either 14 or 7 mcs. by simply Volt lamps. Short wave Transmitter emptying 110 Volts be flexible in order to changing the crystal. He says: "The cost AC for operating "llam" transmitter. Operating 110 V. connection should AC 60 Cycle Radio Receiver In DC districts. Motor Gen- allow for expansion of the glass. If the tube of the 14 mc. crystal is no more than that erator. Public Address Systems. Electric Sirens on motor were mounted solid in some form of recep- of a frequency- doubler stage, and this ar- 'mate. yachts. etc. Camp Lighting. Shoo Warr artificial rangement has certain advantages is "fever" apparatus. Television. Felton Watenrheel for tide, considerable strain may be present in -it Holding or other purposes. Airplane: for lighting strong the glass after the tube has heated. compact, has only one tuning control and search light or electric Mgrs. Laboratory work. etc.. etc. is ready for use at once, without neutraliz- to 't II. P. needed to run generator Coupling to Antenna ing or other adjustments, and to change BLUE -PRINT 22 x 28 In. and Four -Page from one frequency to the other takes but 854 X 12 In. INSTRUCTION SHEETS No antenna coupling arrangement has a few seconds." FREE with Generator. been specified, other than a single -turn link. Generator. as descried. Including four re- e 90 For the plate coil, 12 turns are used on placement cartoon brushes. Blue -print and e7V which is coupled to the input of the 830 -B 7 rocs. and 8 turns on 14 mcs., but the Instruction amplifier. When used as a complete trans- smaller coil functions quite well on both Send 22.00 denoslt balance C.O.D. mitter alone, this oscillator was link -coupled bands, with a decrease of about 5 per cent Shipping weights 18 lbs. to an antenna tuning unit. in the output on 7 me. as compared (Replacement carbon hntehes bought separate $1.50 per with ,et of four. Set inatrurtiane bought separate $1.00.1 In no case was the screen current allowed that when using the larger coil. Using MONFY.11ACR: f l'AR.A \TEE to exceed 30 ma., and the plate current was one coil only, the frequency may be quickly always kept in the neighborhood of 90 ma. changed by plugging in the other crystal WELLWORTH TRADING COMPANY These values provided maximum operating and shiftingone dial. 560 West Washington Bird., Dept SW136, Chicago, Illinois Please mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com 186 SHORT WAVE CRAFT for JULY, 1936

Without doubt you will have to go a long way to buy better make the study of this field of radio much simpler. The volumes books on short waves than you find on this page. Each book is on this page are the finest books on short -waves which are pub- written by a well -known authority on short waves ... each book lished anywhere today. Order one or more copies today . find has been carefully illustrated with photographs and diagrams to out for yourself how fine they are. Prices are postpaid.

101 SHORT-WAVE HOOKUPS How to Get Best Short - t,00rmleu by the hdlto,. .1 511,.11 I A A, h CRAY l' WAGS and .ter, boot -up and diagram Illuseated i. also .r nied by thorough .. len.ar,n of what thk - Wave Reception hook -up ntpli.he.. I,.t pane re required. "'il:nuts,°'ninding u By M. GEItSSRACK information. value. of real r c. in leer. N0W IiAHVEI everything you want to know is order to build) the et or to TO GET This honk tells you everything you ever wanted to know look up H unt .hoeve . ePlion To .urmedl of the important ens whkb have appeared - BEST 'rh.) oiler.. nÁeasion.l radio listener wd die hit for print during the past five years are in tl,i. valuable I elk. loot perunr. rye rio r.ceptioo Seto mush aa the ousel.. Dinsmore. the "1Y' l'winples. lid YII rte l e. Yale flu i)enilllnlyn.. Denton Sta ,1 -hy:' M.to.lyne Triples '1 HORTWWE Why i radi,, li. enabled in pull in . In. ihnbe- Trotter. 2.Tube Superheat. linid glthatobe ,all `Ito, .. .000 tile.. x D era' aml,e Bauery. "rued, Y°S--tube Sat. eÄ.thei 'the t tell,,, :iii . much bee teen. "lioerle atuM A.C.. Doane" S.t,M A C. roerle i aA the ... 1 RECEPTION + peel: , Posed., n !.ripper." Duo R.P. ¿robe Receiver. The Sargent i Pr without nth 9.33 Tapped Coil Receiver. :lohe- Gir.11e. 7. The ,Tuba uo. 1.. . fine °reason wiirr a knowledge of short w` and )rrnp'' -2 Tithe. Equal a. Ham-Band 1-Tub. Pee - they helm,.. tIle are the chapters of this new bwook: wee' Wyeth AII.W.y a. Denton Economy 3. 2,Tith. I. What re Short Wave. and whet can the Deleon beer -OvìRodrne" will he found her.. with loll on dee'ripti.na. In many case.. w` have elan Included picture k! 2. o w °tune and` vten i,, listen in to, the short wave. I.ssk-,,p for those who don wish to follow the re.itlnr 3. Hoe to identify short-save . Y nolic hook-p. but i.h to have. menhir di. 4. rvarnal cheers in hur rertan This is very bandy volume. monotony for ir.those " ' Ty1, of r . or ram ytk n. to mud', ems to ll.e.hurt wave et. (r..u. e. Aerial n u, It .hurl -w.v troOr Ott.ot uiehu to ', theet,. 7. Venmation. from shortmaye . r The even ka. f -old.[ There are á.ic`eli,n .hon-o teuot Ion that even lo ëere do not 0 0. stn 100 Illustrations, 72 Pages, e(. it. Stiff, flexible covers SOC 40 Illustrations, 72 Pages. Stiff, flexible covers HOW TO BECOME AN AMATEUR i 50c RADIO OPERATOR 'E show, l.ierrt. burt,',, F r..1.1, t',, eh. in ntlte tt,i. booíok be orine n tideline. or n r. he wu ihïruewr of radio HOW TO BUILD AND OPERATE telegraphyaphy et the N.C.A. Institute. lie is a ember of the ÌÁ.E. nrutitute of Radio Engineer,. oleo the et.r.n °Wire. SHORT -WAVE RECEIVERS Imo Operators. Aw . io mule operator. rl,111ti is the blest and most up-to-dote hook u to takekeuup ttlrrindi. .irk re,erttualt,- thie te hew book you must the subject. It is edited lind prepared by the net. Y editors of SHORT WAVE CRAFT, and contains Partial List of Contenta a Wealth of material on the building and oiler Ways of learning the Staten, re elv- ration. not only of typical short wave receivers. with 1Ì ,,lt'.word. kdending and but short-wave as Dozens `rr : many r eat, utñorpt. dita.. converters well. of uf laws., irle( Jae o1 c short-waves stets are found In this book, which ,.r,iy sed mee 01 eWle equipment.p Thk chapter .'time Om i of oneraor. Graphic .y'nebul contains hundreds of illustrations; actual pho- e ',,Iio n'nouar tïn ro r. raed to in,ikata the earn.. parley( ..das circuit.. General tographs of sets built, hookups and diagrams tullotulira tlrw,Y' c lard .P Bee u ore bgimw'e liba g:l lore. there:`:. ñdelir s :'hen war mere no a atino into, t n.ivwFoo,l.rnentsl lee. ul lectrk This book is sold only at ridiculously low 4ul.rlY tM,as nerd ir. .Aio ee e.nle,t..J prier because it is per rim to pot tills Vil)R sed :roiga LUic eieuie are adl ,.mI. Ueertptinn uI on able work into the hands of every short -wavy A.t a. bin. meal 'dot cecee by amateurs. You eoi,l uUkewt uith t . t nehusiast. u rAo knmh.q w We knew that If you are at all Interested In Bien 50C150 Illustrations. io s . aaes huit wrd ewee ° i. fiar file , . waves you will not wish to do without this book. It 72 Poses. Stitt, itlt flexible covers l[ oÏ ,i the pub t *b1,et .raÌÌ it most Important and timely radio publication the int 1 Vk.d.t. . ye n Jih.1.. r ` . reference tun, a.. etr. 150 Illustrations, 72 Pages. Stiff, TEN MOST POPULAR SHORT -WAVE flexible covers 50c RECEIVERS -HOW TO MAKE AND WORK THEM

SHORT -WAVE 1 THE t BEGINNER'S 11 ,.1 BOOK rlY F. edivn. Sllhnlss% sr I ,1ht.e. td

book that wl,n your .her , oblea -ese. . HERE:r i . fro pde.t fundamental., reed ih complete.oleo :oderrepresentation. stmt.e of the[ .k,1, sky I the milt I. .ions. roter. Ì. ue ui and mirednl[refer e book on. short e for lire beg er the de. 1o.k l.r ',toroth-1y rated- t -technical... 1. y. .aril eT. Fe om iiÌ '.,, nnn mathematicshe and n Jargon. given tu h.receiver set complete. give.r tremendous of important shown bus tuoperate to in maximum efficient,. elm A i nlve all n

nation. alms! radiar tu°Mnwd ea roil[ .riling audl. - CONTENTim..r tinnnl The Docile 2 -Tube Iteeeicer That Reach.. the 12,500 . [tile Mark. by Welter C. Urerle. o having auf Tuned MOST ttAH Partial List N Contents Radio Frequency. byV(liiliirdvEE. I.'ntotwond iÌ. W. Sector. SNORT WAVE Getting Started in short Sly de l.u.e S -W Receive. Edward i'. 1 .c Weve-the fundamental. of elec- Rinnenp 2,Tuhe 12.000 Mile Reesto., I,yr A. tricity. the Short Rend of Radio-how to reed whe- The DX ts ,diagram.. Short Wave C,il. -varkue types and kind. in Ilinuewea. Jr. Asking the[ Build e .irrt -Weye Receiver in your "Brief- Cue." I.Y RECEIVERS 11,00 Oernebek and Clifford E. Dentin. NOW TO MARC AND r Shot Wave fniel-the int. that d .tes tool aerial Do earl The Denton al'ule A11 ;Wye Recelver. by Clifford E. WORK THEM The Tr. Lead in for S tarie. Denton. The Ik[ SI. t.Wwver Receiver -a simple one tube et The Denton "Ptand'BYh by Clifford E. Denton. th anyone1,r rm. ebu`ld. The "StandORy" Electrified A hart -Wave Receiver. by' Ilse How t lr the Sl pl; Ware Set -tolling the important mint* COAT -POKET to .:c .ba ck and Clifford E. Denton. MCP Au,lio Amplifiers or 1,W Nee The P'W PENTitee n.. Iry ,Ain M. E Louie Marline idea of A Ü nur' : W REtEIVER. 1., I. e greater mont with ths S.W e t. erÏneth °fO tao: .daran. Wire ('hurt -b, maul in the e,.htnweun of ail.. 75 Illustrations, 40 Pages, 75 Illustrations, 40 Pages. Stiff, flexible covers 25c 25C Stiff, flexible covers OVERSEAS All the books shown SHORT WAVE CRAFT, 99 -101 Hudson Street, New York, N. Y. SW -7 -36 on this page are pub- Gentlemen, I enilo,e herewith my remittance for the amount of for which you are to send READERS! n e. Matpnid, the hooka checked IMow. These books can be obtained fron lished exclusively by ( ) How to Get Best Short -Wave Recep- ( ) How to Become an Amateur Radio the following houses: tion soc each Ope 50e each GREAT BRITAIN ( Ten Most Popular Short -Wave Re- Corrine.', SHORT WAVE ( ) 101 Short -Wave Hook -tap Soc each coi How to Make and Work Street, Leicester Them 2Sc each 9a. Green CRAFT ( How to Build and Operate Short -Wave ( ) Short Wave Baeinner'e Bookook London. England SOc each Receiver each 2k FRANCE 99 -101 Hudson Street, Name Editions Radio Addrwr 42 Rue Jacob New York, N. Y. Paris state City AUSTRALIA (Send remittance in form of check or money order. If letter contain. rash or untied C. S. ¡'0.1.,. McGill', C L I P -M A IL Stamp, mentor it.) 193.195, 215 Elirabeth St. L Melbourne. C. 1 Please mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 187

READS AND Can 5 Meter Waves Ex- NO ONE THEN DISCARDS tend Beyond the CONTINENTAL SHORT WAVE CRAFT 5 -TUBE Horizon ? AUTO RADIO (Conan nod rerr page 138) sensitive detector of the receiver at the =_------..... ^. - ...j.- distance given on the ordinate. It is interesting to note, however, that the slope of this curve falls off rapidly as the height of the transmitter increases, particularly above 2,000 feet. Since the early days of 5 -meter working it has been known that a slight bending of the waves occurs, resulting in slightly larger distances being covered. The same thing appears to occur with light rays, for local inhabitants claim that the Eddystone lighthouse can be seen from the summit This is the finest 5 -tube set of Cader Idris (2,927 ft.) on a clear day, a ever offered. Regular price 4, 695 distance of 170 miles. Since the writer has $29.95 Special never been up Cader Idris on a clear day Complete with 5 tubes, ready to use. he cannot substantiate this claim! Fig. 2 Nothing else to buy. shows the effect of this bending property. 5 -tube superheterodyne circuit -very se- Extremely long distances have recently lective, extra sensitive, marvelous tone. Can be installed in 15 minutes in any car. Readers keep their copies for years as a been covered. The Berlin television trans- Ni, suppres rs required. Mounts under dash. steady reference and thousands of letters at missions from the Brocken Mountains have test to this. been received daily by the English Post 4 -Tube 7 Watt Office Engineers, and the German author- It is now possible to save your copies and Amplifier Kit for this purpose we designed a splendid ities have recently been receiving enthus- Buenos A beautifully de- hinder for you which holds twelve copies. It iastic reports from amateurs in signed amplifier, con- is made of beaty substantial material and is Aires and New York. In the last two cases servatively rated at covered with black grain leatherette. The has not the reliability of the reception 7 l watts. Utilizing a name of the magazine is stamped in gold on been maintained. 57 tube and 2- 2A5's. the cover. In the United States of America, con- 80 rectifier. Designed An ingenious mechanical arrangement is sistent two -way communcation between the for 100 to 190 volts, provided which makes it possible to bold the Blue Hill Observatory of Harvard Uni- 50 -60 cycles, A.C. copies flat when reading from the binder. Sold complete with versity and West Hartford has been regu- all parts; chassis, awe, hardware, etc.. obtained at a distance of ninety SHORT WAVE CRAFT Binder as larly -three ready to assemble and wire. Detailed dia- described, prepaid in the United$125 miles. Scheduled reception on 234 days out gram included. Ship wt. 15 lbs. States 1 of 239 days has occurred, and the condi- No. AD 112 7t,¢ Watt Amplifier í49S tions were such as to make it a commer- Kit, less tubes. unwind Canada and foreign countries 25c extra. cial proposition. Farther, Chicago and Amplifier. Completely Wired -....$1.00 extra or cash. We accept money order, check. stamps New York City have been linked by 5- Set of 4 Matched Tubes $1.95 extra meters, the distance in this case being no FREE: 64 -page catalog. Send stamp to cover SHORT WAVE CRAFT less than 720 miles! postage 99 -101 HUDSON ST.. NEW YORK. N. Y. Turning to our own country, we had Mr. AIREX RADIO COMPANY Douglas Walters (G5CV) radiating a small 58 MARKET ST., Dept. 7, NEWARK, N.J. signal from the top of Snowdon and being picked up 207 miles away. Further, the Eddystone transmitter (GGSL), situated at Short Birmingham, 400 feet above sea level, has 1936 WET WAVE WW[ been received South of London, a distance 1.7r--:-a : of 110 miles. The latter is not a freak ¶ThLw! Wave result, since the transmitter is situated in EDITION the heart of a big city, as the accompanying League photograph shows. The theoretical reception distances of the last two stations have 360 PAGES been indicated on the curve of Fig. 1. THE Letter- Two questions arise out of the above reports. First, what atmospheric conditions OVER 400 heads cause such results, and, secondly, what can RADIO we learn from these pioneering experi- ILLUSTRATIONS ments? HANDBOOK AND Designed Readers are well acquainted with the in- DIAGRAMS FOR AMATEURS for direct ray method of reception used on or- 1 4 1 dinary short wavelengths. On the broad- AND EXPERIMENTERS Members cast band the direct ray becomes attenuated Complete after fifty to eighty miles -on short waves it disappears after about twenty miles, Radio Course but signals reappear in the form of an in- AND This is the official letterhead direct wave, perhaps 5,000 miles away. It Valuable is not too fantastic to presume that on the ultra -short wave -lengths, where the direct Reference ray is purely optical, that the indirect ray Guide It is invaluable when it becomes nec- appears at such a distance that it only 0 essary to deal with the radio industry, comes back to this earth during rare at- 0 mospheric conditions. * A meteors and experimenters ".wear mail order houses, radio manufacturers. Io. the facts in this new Ilandlaa,k. It seems to the writer that these long - No apace has been wasted on matter It can be used in many ways and gives distance records should be divided into two which is not of practical use. Nothing been omitted. The hook you a standing. No mem- categories, namely: of value has professional - üconcise. to the faint and profusely ber of the LEAGUE can afford to be (a) Reception from 20 to 100 miles. lmtrated. l'AIRTIAI. LIST t (6) Reception at great distances, i.e., CONTENTS: Learning the Code. without this letterhead. Fundamental Theory of Electricity. above 1,000 miles. Theory of Vammni Tubers. Loth r ing and trans- we some valuable mitting. Receiver Design. Crystaleu Filters. A.V.C., This can only be used by members of Taking case (a), have Operation information available from the American Audio Circuits. Construction and of trans. one else can millers. Fao,oa. Soues h:xeiter. Numerous ( oil Wind- the LEAGUE. No pur- experiments, covering reception up to 100 Ming ('harts. Radio Telephony. Controlled Carrier chase it. odulation. Complete 53 page chapter of lo Meter miles. These experiments have shown that and Ultra-High Frequency Equipment. Complete stratification of the lower atmosphere bends 25 page chapter on All Types of Antennas. Power Take advantage of this opportunity the ultra -short waves over a much larger Supplies. T'est Imtnunent,. Cathode Ray (bcilloceope and Its Application to Short -Wave Receivers and Trans - to handle your LEAGUE correspondence path of reception. Photographic recordings itters. Itegnlatione of the Federal Communication taken over a long interval of time have Commission and Board of l'ire Underwriters. Complete in a business -like manner. List of "Q" Signals, etc.. etc. Sise e'0'. Flexible card- shown that there is a close relation between board covers. See Page 190 for order blank. the periods of large temperature inversion in the lower atmosphere and the periods of ORDER Send rfcaM IM./. .1;11:11..0 Reel... iaÌwM.Iyocamad cub very strongly received signals. The term l ï;TODAY.a SHORT WAVE LEAGUE "temperature inversion" should be defined. 99 -101 Hudson St., New York, N. Y. Normally, as is generally known, the RADIO PUBLICATIONS temperature of the air decreases, or has a (Continued on page 189) 101 Hudson Street New York Please mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com 188 SHORT WAVE CRAFT for JULY, 1936 The only SHORT -WAVE RADIO MANUALS in the radio field-and every fan" needs them!

T HERE has been tremendous progress made in short -waves during the and construction, servicing all -wave receivers or tube changes. or new past few years, and only in the OFFICIAL SHORT -WAVE RADIO scientific discoveries in the short -wave field, all are published chronologi- MANUALS you will find a true picture of the important developments. cally in the OFFICIAL SHORT -WAVE RADIO MANUALS. No other book today tells in accurate detail about the changes that have The OFFICIAL SHORT-WAVE RADIO MANUALS are edited by Hugo come from time to time. Whether the advancement has been in set design Gernsback. Editor of SHORT WAVE CRAFT and H. W. Secor. Managing Editor. 1935 Official Short -Wave Radio Manual 29 * FEATURES 1 I- Short -Wave Ntlnnnrn * 167SueRe[enep r- votive Short-Wave Receivers-lout 7t[ "Pb6Wr r: l.:. I.: u.1' riu,tint Ìan new e "0_rle endt .arve,r.lrt ".""'" n[' Forelan" end...Dometic" Short -W.,. * 2-Short wave Receivers-All era,. I with .u. n_ Wawa and pi . -Tire hot woe. ste. which w1e'..ring * Hlah Fieelnr' -u.. to dn.in it in soon -w.. the .05.nÌ ,Pilot tint v e. detail. me e..wonran. i them, aloe. "öaa Sprea.lin' the UoteI.. 5-tune 'r. R.F. Receive... * The best ShortWave Questions and .wane of rh Receivers 1 -2. k 3 tube wets *3 -B.Rery Shen -Wave - I.. The best Short -Way. of the wars all the r.l 6-tune .0 wrneterodyne. designed * "Rinks" especially for battery operation. 4- "S- Meter" Depanme, t -All the lai -clope"-in- R* Forel[n Short-Way. Review -Nov.1 cocotte apw- Pt Iedin '4,trg lair improved "high oof,.i Y ter '-er.1et- -m r u': ee.i. honk u 31 -Tubes for Sh ortWas. pu ^pesas -lnclr lin ,Ix S- Shore.Waw "Artllleialet 1. Went . , r ra it and Noh'sla.t.asil * -Wave Trr' nslmmer[ .trout the new "Lon. re -All therapeor I.i. pShun *61 Shen -Waved Caper S.. ore-welted with * asho .N' Kink.. *23- MURi-PUrpaa Tebea -II.,. dun ea short N':. which lhe ual t 2e- Ire Receivers. Short Waves- \...,.. r 5...o.,. .t perstw. en.l * Audio Amplifiers" ShatWave Ci,. Ìk2-Ultrar,.iterib n"I in this1l1. 1 5-Commercial "Short-Wwa" ml "All -W. Rm .cive.. 25"Bene- spread -w.w to .prod the al.owr over m s, -Pill Seri-icing 1.,:.. 1.,, ..r. t,. n :.. and * .0.11nr :.-. rein *9 -Now to build "Power Supply" Units is t Short Were 1as "Mono-Coil" Receivers-110.rV[ l ea to mIlinld Receivers. *26 r p.. :il ehmmae l.-r. .In n -Latest Shol -wave Converters-tt.n servicing data CIA"'n,e.t terItr. nSecetetc. .. en tairronweral al-, ur *27- Boosters. PnempUMn and Beat Oscillators- *lo PA tii..,- work. with c...tr etinn I riel.. .l races, .- etc. * II-The Short Warn Ante I l l Äieldel ille. 25- POrtebl Short-Way. Receivers and Transmitters Rednr '. n l a Ilen ln r Double. Doublet. PC -Tr a emitter rower supply from Ford 'ode. etc. *12- Short-Waver SuperheterodYn.s -From 3 to II I.l... ne en n. oral -Ian. radier.. r n.e aryl . oars including AND FOR SERVICr MFR all-wave 13-Phone Transmitters for Amelur Stations-Ii,,w e din w ne. * * .i. .ñ eth. i -i Distance -Heaviside layer. etc. -.. oth, words. W« low beer. Iroorididi line..will ne found yin enlarged ,- *14-"Skip"idolised: pysic. sil :fart W., n. tl:r..n,ri OVER 240 BIG PAGES OVER 1000 ILLUSTRATIONS Size 9x12 /nebes- Flexible Leoreleal Leatherette Binder

1934 Official Short -Wave Radio Manual 411.1 71112. I 15 Valuable Features A large section featori ng the iiu.t Shot t- \Vale IL .rit' eI :(lori how to construct them. Short -Wave Transmitters in all their phases. A complete Ultra Short -Wave Section featuring construction of 1. 3 5 and 10 meter receivers. A complete Short -Wave Beginner's section. These vary from 1 to 7 tube receivers. A section devoted exclusively to coil winding with all information about it. A section on Commercial Short -Wave Receivers. Every important commercial receiver, including all -wave sets, is represented. Full servicing data is included which makes it invaluable for Service Men. A section devoted to A.C. Short -Wave Power Packs and how to build them. A section for the Short -Wave Experimenter and short -wave kinks-hundreds of them. A section on the important new art of Short-Wave Therapy (treatment of diseases by short waves). A section devoted to Short -waive Converters and their construction. Full servicing data on all commercial models is included. . A special section on Short-Wave Antennae and noise eliminating procedures. A section on Short -Wave Sii perheterody nec. This section tells how to build them. including many commercial models of receivers. The latter with complete service data. A section on Amateur 'Phone Transmitters and how to build them. A Short -Wave Physics section on theoretical short -wave data for the advanced experimenter and radio student. A most interesting section on Super- Regeneration in Short -Wave Receivers. Over 2111 Big Pages-Over 1,000 IIIumtraa ions Flexible. Looseleai Leatherette Binder Special Combination Offer! SHORT WAVE CRAFT SWC 736 MAIL 99.101 Hudson Street, New York, N. Y. To give every short -wave enthusiast the opportunity to add Gridiculen: I enclose luira ills toy TVIIIIII3111.0 far vhirh send nc COUPON both SHORT -WAVE RADIO MANUALS to his library postage prepaid. my ropy of Oæ OFFICIAI. SHORT WA \'E 11:11)111 I Volume I and 2) both books, if bought together. can be ]IAN1'a I. as indicated helo,v. TODAY purchased at a saving. Each Manual sells regularly for 1 19tt OFFICIAL SHORT WAVE RADIO MANUAL-P.2.50 52.50. If both are bought. NOW, the price is S1.50. t 1 Peli OFFICIAI. SHORT WAVE RADIO MANUAL-V.741 YOU CAN SAVE FIFTY CENTS BY BUYING THE TWO Roth Manuals -$4.50 MANUAI.S.

Neme A dilress SHORT WAVE CRAFT Pity State 99 -101 Hudson Street New York, N. Y. ('lease mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 189 5 Meter Waves Beyond the Horizon (Coa.tinued from page 187) CLASSIFIED are inserted at 5c word to strictly amateurs, or 10c a word to manufacturers lapse of 1 deg. C. for every 300 feet Advertisements per or rate dealers. Each word in a name and address is counted. Cash should accompany all orders. Copy rise in elevation. Sometimes, however, the for the August issue should reach us not later than 5. temperature does not fall as rapidly as this, June in fact it may rise, and a temperature inversion is said to take place. To put it GENERATORS INSTRUCTION SHORT WAVE COMPONENTS simply, a layer of warm air on top of a layer of cool air causes good reception 4 BAKELITE l'1.I (i IN COILS, if a sub- TURN St'tlAI' INTO ]CONEY. RADIO SUMMER SCHOOL - wound on tube bases .30. tall fonos .10, conditions. It was found that Autopower shows you how easily and 'nurses for Amateure, Senicemen, six prong .60. Noel, 728 Birch, normal lapse rate occurred between 900 ecommnically auto generators can I.e Conmw'reial Operators. Classroom, lab- Scranton, Pa. and 7,500 feet high, then a large signal converted Into A.C. or D.C. generators oratory anti field oork. June 15 to and D.C. motors. 2 to 1000 vnita; for August 8. Perlman Engineering SHORT WAVE RECEIVERS was obtained over the path of reception. sound, radio, power, light, or welling. Srhmd, Valparaiso. Indiana. When the air mass conditions were not so No previous experience necessary-com- IG -Nlac plete Information all in new book. with RADIO ENGINEERING. BROAD - :CEIV17lt5- AND USED. heterogeneous and a normal temperature simple Instructions and illustrations. casting, aviation and pollee radio. Serv- Bold and traded in. Ilanmarl unis. dropped back to Endorsed by thousands. Only $1.00 icing. marine and Morse Telegraphy Nationals, Itn1I7, Skyrider. :kiuvar lapse rate occurred, signals taught thoroughly. All expenses low. Radio Service, 15 Lawrence of hourly postpaid. Autopooer, Inc., 414 S. Ave., very low levels. Comparison Hoyt Ave., Chicago. Catalog free. Dodge'. Institute. Colt Dumont. N. J. readings taken shows that signal strength St-, Valparaiso, Ind. and high during the INSTRUCTIONS It DISTANCE is lowest at mid -day RADIO INSTRUCTION-El. a les- Costal Sets -record 2100 miles; 'Its - 10 p.m. 7 a.m. So clearly do the son Iñtuipnrnt ]tented. Missouri liedntlbler" period to "HAM" OFFERS AND WANTS Srh,ol, year, 2e laboratories, measure- Technical 3907 N. 25th. SL 151 -A Liberty. San Francise,. signal strength and lapse rate I ui , \I ments coincide that it is even suggested BI,Y YO110 UDC/AVER ON that 5 -meter receivers and transmitters $lvYRIDER BARGAINS. ALI. MISCELLANEOUS Hinds' "Easy Payment" flan. write models. ell or trade. 19hilm 16 -5 u may be used in the future by the meteorolo- Hinds & Edgerton. 19 S. Wella BL. Lund chassis, new $36.00 Erica Cam- OHM'S LAW Chicago, Illinois. gist. In the case of extremely long eras. \Nelle- $toith Radio Corp.. 28 CAT,CiII.ATOR- North Wells Street. Chicago. Illinois. Lightning Slide Rule: mires all prob- beig covered (b), the mely idistances lems of Voltage. Current and Resist- TELEVISION able is very vague. Some authorities have ance, Power, Wire Slzes, etc. Range I micro-amp. to 1000 amps.: 1 micro-volt WANTID COPY OF LODGES TELEVIS(IIts. KITS. $13.00. $6.00, suggested that the sky wave pierces the 10.000 volts: 1 to 10 meg- "Signalling Through Spare Without to micro-ohm $4.00. Arthur ('old. 2134 l'aluns, De- upper ionized layers and is finally reflected Wires." State price and condition. ohms; I micro-watt to 10 megawattts; troit, \llrh. W. Short Wave wire Ore. 0 to 36 R. A S. gauge. In- back from some heavenly body! II. Seer, % Craft. $1.00 99 Hudson Ht., New York CRY. troductory price prepaid. The However, it is highly probable that a Dalaprint Co., Box 322, Ramsey. N.J. TRANSMITTING EQUIPMENT highly ionized layer does exist well above Heaviside and Appleton layers, as TRADE GROSS CR2S CWTRANS- 081- CARDS -SWL A COMPLETE CRYSTAL CON- the Iller. output 25 to 30 watts, complete. trolled transmitter for $20! Includes shown in Fig. 3 (a), and signals are not One All -Star Jr. Receiver. And one SHORT WAVE LISTENER'S. prever supply. crystal. rolls. all tubes. wired often heard, either because of the limited monitor. l'or all wave radios. or what GSI.s Cards. Reedy getters - Samples and tested. Write for details. have you. Dleyford Ogle, Gatllnburg. (Stamps/. W- S- E -S -N. Is27 ('our, (:ustombuilders, 113 'Pest 57th Ht., number of listening posts or else the layer Tenn. Toledo. Ohio. New York City. is insufficiently ionized for reflection. Al- a few miles QSL CARDS. NEAT. ATTRAC- ALL METAL CRYSTAL 1101.1)ER. ternately, two layers hundred SACItIFICE NATIONAL SWl. tire. reasonably priced. samples free. for Transmitters. guaranteed $1.77. above the earth's surface could cause dis- 1st t:Nrelsine Minn 'filler. Printer. Ambler. Pa. Schwarz Radio Service. Titoism!. N. .1. tant signals by a combination of refraction and reflection, as indicated in Fig. 3 (b). Which of these thories is correct time THE ONE AND ONLY and experiment alone will tell, and up to the time of writing we can draw the following conclusions for an elevated transmitter of relatively high power (25 -50 Encyclopedia on Short Waves watts):- (a) 5 -meter signals give good reliable signals for police working, etc., up to By C. R. Leutz and R. B. Gable five or six miles in densely populated areas. (b) Thirty miles is the normal reliable ;.IIOIt'l' R'AVl.S` is ritten by l.rutz and Gable, two foremost radio be authorities. T ou mill fi remember t' ha ries R. Leutz as one of the pinneer-. distance over which reception can In radio. also designer and manufacturer of the famous LECTz Transoceanic obtained under usual circumstances, i.e., Receivers. Mr. Robes Gable owned and operated one of the finest loo power broadcasting stations in the country. Ile is well known as an experimenter over flat, open country. and research storker in scientific fields. (e) Signals up to 100 miles can he Considering the value of this lack for data alone, Its est should redly be received only if the lapse rate of the more than originally asked. But ohen you see the Illustrations in the book You will mane) at how this hook could be sold for ONE DOLLAR. It lower atmosphere is subnormal. originally sold for $2.98. (d) Greater distances are obtained The book is printed on a very expensive super- ralendered paper. It contains conditions. 384 pages with over 345 photographic illustrations and diagrams. The supply during rare atmospheric of these laa.ks is not expected to last long. Once they are gone no additional IVirrle.sa World, London. copies will I.e available. 0111)510 NOW -he sure to tell your friends about this remarkable book value. Send the coupon today for your copy of '51111101' WAVES- by Leulz and Gable. YOU SAVE 51.98 JUST AS LONG AS THE The All -Wave SUPPLY OF THIS BOOK LASTS! THIS 384 Pages -Over BOOK ORIGINALLY SOLD FOR $2.98 "Aircraft 3" 345 Illustrations (Continued from page 141) Bound hand- SHORT WAVES" is the most important and compre- somely In red hensive volume of short -waves ever published. This book creased with the variable condenser all the has EVERYTHING on short -waves -it literally contains linenl stiff a complete education on short- waves. way out. covers. Size6X9' The 140 mmf. condenser and the 325 mmf. condenser have the ends of the last plates slightly nicked so that when the Partial Contents of ''Short Wares" MAIL COUPON TODAY! condensers are all the way open they be- Hence, when using HISTORICAL REVIEW come short- circuited. SHORT WAVE PROPAGATION RADIO PUBLICATIONS. Dept. SWC -7.36 on broadcast band or on the COMMERCIAL RADIO TELEPHONY the set the AND TELEGRAPHY 103 Hudson Street. New York, N.V. short waves, the 325 mmf. is opened fully, TO RADIO TELEPHONY SHIP SHORE .., t.m.n' l: uA,....i .n il luu,l my remittance al Mae u,Ito,.Sil thus being shorted out of the circuit. On DIRECTIONAL ANTENNAE ..n. money a der ,. pew U. r gran., I,, .hieh end .,. nn. operation, the 140 mmf. con- TELEVISION uapr al ...SHORT WAVE, 1., Lentz +ml 0n1,í . I der and long -wave AIRCRAFT RADIO EQUIPMENT OM. tom. .ahe n. du . ils Ì n ..,oat denser is shorted out in the same way, per- SHORT WAVE BROADCAST RECEIVERS neehonk ...,, n1i y money refunded. 325 mmf. variable to tune the ULTRA SHORT WAVES (Medical and Sol-gloat mitting the Applications) long -wave coil and bring in the desired AMATEUR SHORT -WAVE EQUIPMENT long -wave stations. NAniH...... _..._...._..__....___.-._.-...... _.-._.___.-..._ Don't forget that this comprehensive volume is sold on a MOSEY -BACK GUARANTEE. If you are not setl.- Detection Used days for refund. Use Grid -leak fied with R. return it within three ADDRESS . ._ the coupon at the left for ordering your copy of "SHOAT The other features of the circuit are WAVES" by Leutz and Gable. more or less conventional, including grid - CITY ___ ...... STATF. leak detection and the standard method of RADIO PUBLICATIONS dnebde a g]so ehargosl regeneration control. Although it is pos- 103 Hudson St. New York, N. Y. fér:ian eeunerl:sng sible to operate a small magnetic speaker on a great many of the strong stations 8 11 /16''x1 /16" in thickness, fastened to a condensers. The other parts are mounted with this set, it has been designed es- wood base or sub -panel by means of wood on the aluminum panel. Be sure to insulate pecially for earphone reception. screws. the 325 mmf. variable from the panel. The The three tube sockets are mounted in a illustration shows the arrangement very Construction of Set row on the wood base; also, the grid -leak clearly. The plug-in coil can be seen at An aluminum panel was selected, 7% "x and condenser and a few other small fixed (Continued on page 191) Please mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com 190 SHORT WAVE CRAFT for JULY, 1936 ... SHORT WAVE ESSENTIALS FOR MEMBERS OF THE SHORT WAVE LEAGUE .. SHORT WAVE LEAGUE LETTERHEADS Application for Membership A beautiful letterhead bus been designed fur weathers' correspondence. It Is the official letterhead fur all members. The letterhead is Invaluable when it SHORT WAVE LEAGUE becomes necessary to deal with the radio industry, mall order houses. radio manu- SHORT WAVE LEAGUE 7.36 facturera, and the like; as many houses have offered to give members who write 99 -101 Hudson Street, New York, N. Y. on the LEAGUE'S letterhead u preferential discount. The letterhead Is also I. the undersigned. herewith desire to apply for mem- absolutely essential when writing for verification to radio stations either Isere oor bership In the SHORT WAVE LEAGUE. In Joining the abroad. It automatically gives you a professional standing. 50Ca 1 assessed for mem- LEAGUE I understand that am not A -SHORT WAVE LEAGUE letterheads, per 100 ev77VV bership and that there are no duel and no fees of any kind. I pledge myself to abide by all the rules and reg- OFFICIAL SHORT WAVE LISTENER MAGAZINE ulations of the SHORT WAVE LEAGUE, which rules The finest magazine of Its kind ever published different in get -up and you are to send to me on receipt of this application. -totally contents (rural any other. t 'out o I consider myself belonging to the following class (put ins the largest listing of short wave stations In an X in correct Apace): Short Wave Experimenter the world, up -tu- the- adaute, Including " Police,'' -Television" sod short -wave Short Wave Fan D Radio Engineer Student stations, as well as a special list of the star short -wave sULLions with their fre- I own the following radio equipment: quencies and call letters. Also contains photos and descriptions of short -wave A -50e par 100 broadcasting stations in various parrs of the world with photos of short wave Transmitting ._ studio artists -How to locate "wen k" distance stations, and other hints for the short -wave Iish.uer "- truest ion and Answer Department for the 'llstewr'- Sllver Clip Trophy Is -vi at t0 Call fetters...... _..___.._..__.___.-- ._._'__ for pled,' readers' listening "Pasts," eta B- Official Short Wave Listener Magazine.._.._ _.._ Prepaid 15C Receiving RADIO MAP OF THE WORLD AND STATION FINDER The finest device of Its kind published. The world's mop on heavy board is Name divided Into 23 sections, white the ruts ry disc shows you imuledin tel)' the exert time in any foreign gives Address country. Invulnnble In loggiug foreign stations. Also call letters assigned to all nations. Size 11 "x__ . C Map 5c City and Stete -Radio of the World and Station Finder.._.._- .. -.. -- Prepaid GLOBE OF THE WORLD Country This highly inglortant essential Is an ornament for every den or study. It is at awtage and for my Member. `lobe. 6 in. in diameter, in fifteen glazed such a way can .loo Tor printed colors. in that it 1aáóé los he washed. This globe helps you to intelligently log your foreign stations. The base is of solid walnut, and the send-meridian of at nickel -like metal Fntire device substantially made, and will give an attractive appearance to every B -15e per copy station. emphasizing the long -distance work of the operator. D -Globe of the World Prepaid 89c A FEW WORDS AS TO THE PURPOSE OF THE LEAGUE SHORT WAVE LEAGUE LAPEL BUTTON This beautiful button Is made in hard enamel in four colors, red. white, blue The SHORT WAVE LEAGUE was founded and gold. It measures three quai riera of an inch in allai meter. I3y wearing this in 1930. Honorary Directors are as follows: button, other members will recognize you nod It will give you a professional air. Dr. Lee de Forest, John L. Reinartz, D. Made in bronze, gold filled. not plated. Muet be seen to be appreciated. E. Replogle, Hollis Baird. E. T. Somerset, E -SHORT WAVE LEAGUE lapel button Prepaid39e Baron Manfred von Ardenne. Hugo Gerns- EE-SHORT WAVE LEAGUE lapel button, like the one described back, Executive Secretary. above but in solid gold Prepaid $2.00 The SHORT WAVE LEAGUE is a scien- SHORT WAVE LEAGUE SEALS tific membership organization for the pro- These seals or stickers are executed in three colors and measure I% in. in motion of the short wave art. There are diameter, and are gummed on one side. They are used by members to affix to no dues, no fees, no initiations, in connec- stationery, letterheads, envelopes. pastel cards and the Il ke. The sell ignifias tion with the LEAGUE. No one makes any that you are s member of the SHORT WAVE LEAGUE. Sold in 26 slots or money from it; no one derive. any salary. multi ffirs only. + The only income which the LEAGUE has is G -SHORT WAVE LEAGUE seals per 25. Prepaid from its short wave essentials. A pamphlet SHORT WAVE MAP OF THE WORLD setting forth the LEAGUE'S numerous as- This benutifut map, measuring 15:20 in. and printed in IR colors is indis- pirations and purposes will be sent to any- pensable when hung in sight or placed "under the glass" on the table or wall of one on receipt of a 3c stamp to cover the short waive enthusiast. It contains a wealth of information such as disumces postage. to all parts of the world, political nature of the country in which a broadcast tation is lontted. etc.. and from the manner in which the snap is hll asked off Elves FREE MEMBERSHIP CERTIFICATE the time In different parts of the world at a glance. F -SHORT WAVE Map of the World Prepaid 25c As ss,. as are enrolled 1 member, PLEASE NOTE THAT ABOVE ESSENTIALS ARE SOLD ONLY TO a beautiful certi tics to with the y LEAGUE'S MEMBERS OF THE LEAGUE -NOT TO NON -MEMBERS WITH EXCEP- seal Will be sent to you. providing 10e in TION OF ITEM B. stamps or coin is sent for mailing charges. Send all orders for short wave essentials to SHORT WAVE LEAGUE. Members are entitled to preferential dis- 99 -101 Hudson New counts when buying radio merchandise from Street, York City. firms who have agreed to allow lower If vim do not wish to mutilate the mnzagine. you may copy ..inter or both coupons numerous on li st,vq of lasts -r. prices to all SHORT WAVE LEAGUE members. SHORT WAVE LEAGUE 99 101 Hudson St., New York, N. Y.

itri qr ÿ Ain, a 40'c# Shod Ur6.f dgIlr r ' w - :or i y.....e .. K1:1.é / e D-69c each

ï , all ! , f G-16e for 25

g . v is LL,itl. L ...i.r.:.r. :.A. I.ttr-An.A AAA E 31e each F--25c each

on the Free menthe, If you wish your name engraved WAVE LEAGUE. 0v -ini iiudwn street. New York. N. Y. statue. please send 27a` SHORT ship certificate. as illustrated Gentlemen to emer cost . I ern already an nrolled member in the SHORT WAVE LEAGUE SHORT WAVE ESSENTIALS LISTED HERE SOLD I an, new I read the as lheted a,, chudewtieem.nl: ONLY TO SHORT WAVE LEAGUE MEMBERS lee,. mer lollo.io.t abortnosc.....monde They canner be bought by anyone unless he has already enrolled as one of the members of the SHORT WAVE LEAGUE or signs the blank on this page (which automatically enrolls him as a member, always provided that Ile is a short wave experimenter. a short wave to. oleic» I enelu.e a here* die fan, radio engineer, radio student, etc.). cash or new U. S. Sump. In any desumkmtion. Reutner eneh nod Mamma i The LEAGUE .eupte money orde.. Inasmuch as the LEAGUE Is International. Nam. It makes no difference whether you are a or any other Addis citizen of the United States and SIM. elan to all SC City touutrv. 'l'h,. LI<.V :1'r is Coven

11casc mention SHORT WAVE CRAFT when writing advertisers

www.americanradiohistory.com SHORT WAVE CRAFT for JULY, 1936 191 "Aircraft 3" Index to Advertisers I I (Continued from page 189) the upper left, with the station selector at the top center. The four battery leads A come out of the panel at the lower right. Ace Radio Laboratork, 173, 179 Aerovox Corporation 169 Complete List of Parts Required for the Airex Radio Company.. 187 All Wave Aircraft Three Allied Engineering Imt irone 182 Allied Radio Corp - 176 CI- Hammarlund Star Midget Variable Con- American Microphone t'o._. _. .173 denser type SM -l5 Amperite Company ttiU, 173 C2- Cornell -Dubilier Mica Condenser, .00005 mf., Arco Tube Company 174 type 5W -5Q5 ANYEARN$30 S40,S50andUP,aWEE? Astatic Microphone LaboratGo Imo. 185 C3- Hammarlund Midget Variable Condenser, a Others go in business and make type MC -140 -M up to and more a year! B Variable Condenser. 55,000 C4- Hammarlund Midget on't care if you are l6or 40 yearsold,Gaeta-kit a offers Bliley Electric Co 171 -M 177 type MC -325 u an opportunity to forever say good -bye tolayoffs low Brush Development Co., The C5- Cornell -Dubilier Mica Condenser, .0001 mf., and uncertamies. Decide today, to get into a line money- Bud Radio, Inc 170 making field where opportunities really exist for real money type 2W -5T1 rmaking jobs or where at is easy to start a business of your own, C C6- Cornell -Dubilier Mica Condenser, .0005 mf., Cameradio Co 171 type 5W-5T5 I'LL FINANCE YOUR TRAINING! Co 178 Dubilier "Cub" Tubular Condenser. Hundreds of v students get Coyne trainingfkst ... Candler System C7 -Cornell- then pay their tuition in easy monthly payments out of increased Chicago Radio Apparatus Co., Inc 173 .01 mf. type BA-4S1 earnings after they graduate. Send lay for details of Classified Advertisements 189 Cornell -Dubilier "Cub" Tubular Condenser, 5, y Tuition Auer Graduation' áf: C8- Ñgetmay my training d do not have to start paying bark until Cornell -Dubilier Corporation 167 01 mf. type BA -4S1 from data you start school, or GO dal, after your re- Coyne Electrical & Radio School 129, 191 C9- Cornell -Dubilier "Dwarf Tiger" Condenser, quired 12 -weeks training period la over. Crowe Name Plate & Mfg. Co 172 .005 mf., type DT -6D5 Tubular Condenser, Learn By Doing In Coyne Shops D C10- Cornell -Dubilier "Cub" Come to Chicago and get your training in the great Dataprint Company 176 1 mf.. type BA -4P1 Coyne Sleeps. l'rnrneat work-not books. You don't need previ- Mica Condenser. .0005 mf., ous experience or lot . f book learning. Many while Dodge's Institute 178 Cil- Cornell -Dubilier eming.` employment service after graduation. type 5W -5T5 Malt coupon today for my big free hook all details of w, E Resistor, 1 meg., ?!, watt training. m al offer of Diesel Engine,sa Electrical Refie- R1- I.R.C. Metallized and Air Conditioning instructon, and my Pay After Eagle Radio Co 169 R2- Electrad Regeneration Control Poten- Gationraduation" Plan. Eilen Radio Laboratories 165, 172 tiometer with Switch (Sw2), 76,000 ohms. Electrad. Inc 177 type 202 COYNE ELECTRICAL SCHOOL Everyday & Mechanics 184 500 5. Pauline Street, Dept.B6 -e2, Chicago, Ill. Science R3- I.R.C. Metallized Resistor, 170,000 ohms, .,k F 14 watt COYNE ELECTRICAL SCHOOL. N.C. Lewis,Pres ; First National Television. Inc 178 R4- IA Metallized Resistor. 1 meg., % watt 500 S. Paulin St., Dept. Bel-83 Chicago, ill. R5- I.R.C. Metallized Resistor, 170,000 ohms, Send your tree (took and special ouer to nay for my training in I G t_ easy monthly payments after I graduate. General Engineering Corp 179 watt 179 R6- Í.R.C. Metallized Resistor, 1 meg.. 1/t watt HAM? G. F. Sign Co Electrad Filament Control, 30 ohm, type Goldentone Radio Co 172 R7- I ADDRFSS Cold Shield Products Co 166, 172 182 270 -W Guy Stokely Radio Corp. Inside Front Cover SW I- Single -Pole. Single- Throw, Rotary Switch STATE SW2- Switch on Electrad Potentiometer R2 L a Mail In envelope or poste on p -[sand H BPI- Antenna Binding Past, Eby Hallicrafters, Inc. 175 BP2- Ground Post, Fahnstock Clip (Fastens di- I fammarlund Manufacturing Co., Inc 167 rectly to panel) Harrison Radio Company 166 VI, V2, V3 -30 -type Tubes I LI -Set of Five Hammarlund 4 -prong Plug -in Tnstructograph Company 178 Coils. covering 17 to 550 meters Insuline Corp. of America 173 LI- Special Long -wave Coil (See directions in text) MAILING LISTS .1 Coil Socket .Toby & Careers 181 1- Four -prong Alden 3 .4 -prong Wafer Sockets for tubes GET OUR FREE K 1 -Four lead battery Cable with different col- Korrol Mfg. Co., Inc 176 ored wires L 1 -Blan Aluminum Panel 77i, "x8 11'16 "x1 /16" REFERENCE Lancaster. Allwine & Romme' 176 1 -Wood Base (sub -panel) Lejay Manufacturing Co 177 1- Carrying Case, (see sketch) WWI Lynch, Arthur H., Inc 172 5 -Knobs BOOK Mc 1 -Bar Knob MAILING 1- Crowe Calibrated Dial and Crowe Name- McElroy. T. R 178 plates LIST CATALOG M 1 -pair of light -weight Acme earphones, with M. & H. Sporting Goods Co 170 ear cushions Marine Radio Company 173 2- Compact type 45 -volt "B" Batteries Midwest Radio Corp 172 2- Compact type l'h2 volt dry cell ( "A" bat- N teries). Eveready National Company. Inc 179 1 -Roll Hook -up Wire. push -hark type National Radio Institute Back Cover Assorted Hardware. a. od screws. etc, Gives counts and prices on accurate guaranteed o mailing lists of all classes of business enter- Oxford -Tartak Radin Corp 176 prises in the U. S. Wholesalers-Retailers- P Short Wave Scout Manufacturers by classification and state. Also Polk. R. L., & Co 191 hundreds of selections of individuals such as R News professional men, auto owners, income lists, etc. pa' +lo & Television Institute. In ". 178 (Continue,1 Horn pope 156) Write today for your copy Radio Constructors Labs Inside Rack Cover Radio-Craft .....191 At this time, this station can be heard Radio Handbook. The _1117 almost any morning at 6 a.m., E.S.T. Radio Publications 1'2. 183 164 DZB, 10.04 mc. heard very well on the R. L. POLK & CO Radio Training Assn. of America _.. 176 24 at 3.15 p.m., E.S.T. Also HI3U, Santia- Polk Bldg.- Detroit, Mich. RCA Institutes. inc. . 178 go City, Dom. Rep. on 6.38 mc. at 6.25 RCA Manufacturing Co., Inc 181 etc., coming in a good QSA5, R8. Branches in Principal Cities S At 6:35 p.m.. E.S.T. on 24th March, World's Largest City Directory Publishers Sargent, E. M.. Co _.. _. 171 W2XAD on 15.33 me. sent a special test Mailing List Compilers. Business Statis- Short Wave Coil Book 174 well. Producers et Direct Mail Advertising. Short Wave League 173, 187. 190 program which was received very tics. Short Wave Manuals 186 TISWS, Puntarenas, "Ecos del Pacifico.' Short Waves 189 on 7,55 mc. heard with a fair signal, but T badly QRm'd and plenty atmospherics. Teleplex Co 172. 17R Time 9:28 p.m., E.S.T. Triplett Electrical Instrument Co. 170 TIEP, "La Voz del Tropico, 6.71 mc. re- RADIO'S Tri -State College...... _ _... esse 17R ceived very well at 9:35 p.m., E.S.T. on Try -Mo Radio Co., Inc ..170 March 24, QSA 5 R9. LIVEST MAGAZINE U CO9WR, Sancti Spiritus. Cuba, on 6.28 Edited by HUGO GERNSBACK Ultra High Frequency Products Company ....173 10 p.m., on Radio me. with an R9 signal at E.S.T. Uncle Dave's Shack is devoted to gen- _. __176 28th March, The address given was P. 0. RAD10 -CRAFT United Radio & Tel. Co.__ Cuba. eral Radio in all Its phases, to United Radio Company...... 168 Box 85, Sancti Spiritus, Radio Servlring and to the ail W VE9HX, Halifax, 6.11 mc. was heard at ramrod set builder and Radio Tech- 172, 185 7:30 p.m., badly heterodyned by another nician. Kinks show simple ways Wellworth Trading Company out of difficult problems. The lat- Wholesale Radio Service Co., Inc 175 Spanish station on the same frequency, est radio equipment Is Illustrate[ Woman's Digest ....184 HJ4ABP. and described. Wright- DeCoster, Inc 166 RNE, Radio Centre, Moscow, on 12 mc. 8 X and was Months for RADIO -CRAFT Is fully Illustrated now heard in the afternoons, re- with photographs, diagrams and R.L. Radio Laboratories 171 ceived here with R8 signal XECR 738 me sketches. Each Issue contains over came in with a beautiful signal QSA5R8. $1.00 150 illustrations. Sample copy -I5r. ALBERT J. YOUNG, (While every precaution is taken to insure accuracy, we cannot guarantee against the pos- General Pcst Office, RADIO -CRAFT sibility of an occasional change or omission in Port of Spain, 99C Hudson Street New York, N. Y. the preparation of this index.) Trinidad, B.W.I. Please mention SHORT WAVE CRAFT when writing advertie' -

www.americanradiohistory.com 192 SHORT WAVE CRAFT for JULY, 1936

Yes! The globe revolves!

NEVER in the six years that SHORT WAVE CRAFT has been published. have we found anything that is as useful and ornamental as the WORLD -GLOBE LAMP we now offer free to our readers. This beautiful WORLD -GLOBE LAMP measures 171/2" high. The attractively colored shade, with nautical and map designs, is 8" in height and 16" in diameter. It is made of fine quality parch- ment, highly glazed, to assure long life. A slightly damp cloth quickly removes dust from the shade. The 61/4" globe, printed in many colors, has a full meridian, and rotates. Hundreds of names -countries, cities, rivers, oceans and others are clearly printed on the globe. Another feature on this WORLD -GLOBE LAMP is the 7norable hour scale found at the north pole. This permits determining the correct time in any part of the world. The metal parts are finished in antique bronze. A piece of heavy green felt is glued under the base, therefore it may be placed anywhere, without fear of marring table, desk, etc. The weight of the WORLD -GLOBE LAMP is nearly three pounds. When packed for shipping, six pounds. Here is the way to get this beautiful prize. Fill in the coupon in the left hand corner -cut it out and mail it to us together with your remittance of $2.50. You will receive a full year's subscription (12 months) to SHORT WAVE CRAFT -the greatest short -wave magazine in the world today. In addition, we will send you absolutely FREE one of these handsome WORLD -GLOBE LAMPS. Old sub- scribers may renew their subscription now for another year following expiration of their present one and still receive this WORLD -GLOBE LAMP. MAIL Only a limited number of WORLD -GLOBE LAMPS are available. Take advantage of this offer without delay in order to insure receiving your free gift. RUSH THE COUPON TODAY. COUPON Just a Word About SHORT WAVE CRAFT The magazine you are now reading clearly indicates the contents of future issues. Over a quarter of a MILLION of the TODAY! most successful SHORT WAVE technicians in all parts of the world obtained their radio education through the Regular departments appearing in each issue Hugo Gernsback's Editorials -forward looking Radio Amateur Course-complete series. World Wide Short Wave Review- exc/usire. Short Wave Scout News. SHORT WAVE CRAFT SWC -736 What's New in Short Vinave Apparatus. 99 Hudson Street. New York, N. Y. Constructional articles on tested and approved sets. C nnlooep: Enclosed sou will rind my remittance of $1.30 igl% Short Wave Stations of the World -corrected monthly. ruts shinning charges) for which enter my subscription for SHORT Short Wave Questions and Answers -educational. This amount chilli le. i WVEA CRAFT for une year U2 Issues I. Short Waves and Long Raves -our readers' FORUM. to a WORLD-GLOBE LAMP free. See chart nett to coupon for shipping chargea on WORLD -GLOBE LAMP. Short Wave Kinks " -with prize offerings. send me me Short Wave League- discussions of our members. 1 1 Enclosed tied my remittance of $2.30. please WORLD- GLOIIF. LAMP by express, collect. When to Listen In- naming the best foreign programs. Every issue contains over 150 photographs and wiring diagrams. Reed SHORT WAVE CRAFT eer) month to keep abreast trills ut tr things happening in this field. Name How to Order Your WORLD -GLOBE LAMP Simply till In the rntla111 at the left and mail together unit check or money order. Register .Address letter If rash or coin is sent. To cover shipping charges on WORLD- MI.OIIE LAMP, aid to your remittance the amount Indicated. If you are located: East of the Mississippi sold 47 . t.: Between the Mississippi and the west Coast add 70 rents; Foreign Countries add 84 cents. d Any City _. _.. _.. State excess remittance %ill be refunded. I Send remittance In form of chuck or money order- register letter if it rnttalne rash. stamps. or eurnttey' SHORT WAVE CRAFT J 99 HUDSON STREET NEW YORK. N. Y. Please mention SHORT WAVE CRAFT when writing advertisers

R.t%t.F: ltRO+. CO., PRINTERS

www.americanradiohistory.com HAYNES RSR 5 -TUBE RECEIVER 21/2 TO 555 METERS HAS BEEN ACCEPTED AS THE "IDEAL EXPERIMENTER'S SET" ENTHUSIASTIC reports from the hundreds of R -S -R users testify to the consistent, fine foreign reception these receivers are delivering all over the country.

NOT just another radio, but a really fine Look at These Features! regenerative receiver, properly engineered from beginning to end. * Self contained power supply. Smooth, stable regenerative control with electrical bandspread over * Multi -band switching (no plug -in coils) down to 15 meters. its entire tremendous tuning range plus extremely sensitive super- regener- * High efficiency plug -in coils below 15 meters with ative action below 15 meters. Whether it is long distance foreign recep- super- regeneration. * Electrical plus mechanical band -spread. tion you want or a 40 megacycle, high fidelity local broadcast -a flip of a * Dual regeneration control. switch and "you're with R -S -R. there" the HAYNES * Hiss control un super -regeneration. * Perfect lugging and absolute stability on super -regeneration. * Dynamic speaker and earphone reception-

EDITORIAL COMMENTS * Tubes used -2 6K7's, 1 MG25Z5, 1 MG43. The New York Sun; Mar. 7th: - and 1 76. Circnrits worthy of space are not numerous this season, bru the R -S -R is an exception. When demonstrated to the editors, the receiver functioned so smoothly that it was obvious its many features would appeal to the home experimenter. NOTE Here in one cabinet is a receiver that reach from the lop of the broadcast will The R -S -R is already being copied. We ex- band down through the short -wave channels ultra short -wave all to the band, pected this. When a job is well done it is al- where the two-way police systems are active and where television uill soon be ways imitated. We could produce the R -S -R carving its way. -Ed. Note. a little cheaper by cutting corners here and Radio there: using a cheaper speaker: etc - News; May '36:- 'l'his, however. is nut our idea of good econ- "A Real Go- Getter -Under test in two New York City Listening Posts, the re- omy. The R -S -R is built to Mr. Haynes' ex- ceiver considerably exceeded expectations. Short -wave stations were tuned in, all act specifications and every part we use in it on the loudspeaker, from Spain, Italy, England, France, Germany, Colombia, has been approved by him. Cuba, Canada (and of course the U.S.), on the 25 -, 31- and 49 -meter hands. Ama- There is only ONE authentic HAYNES R -S -R teur stations were tuned in on all bands, the most distant being on the 20- and 75- and it is built by RACO. meter bands." ORDER DIRECT FROM THIS AD Short Wave News & Technical Review; May '36:- "11 (the R -S-R) is a well -designed regencralire and super -regenerative circuit Complete R -a -R set: wired. tested, I with exceptionally fine control and, given a fair location and good antenna, ex- tubes. ,speaker. and rabinet. heady io g and operate I cellent long distance reception can he accomplished with it on all of the short pm In ware hands It is a whole lot of receiver for very little money." speaker. tanned, 'nit wires ,bmamle( e ... I speaker, poster nned and ring) tesI l ü I -And Many Others, Too Numerous To List. ,.il assembly (less cabinet and tubes).... I These opinions are the result of actual unbiased tests made by the editors of these publications.

A 3 -TUBE POWER TRANSCEIVER

That Tops Them All ! 3 -Tube Portable Transceiver t Ilene Is the latest model All Electric 2 -Tube Transceiver 'completely self eon - tand i unity coupled of the well -known For the ham or be- ureter transceiver 5 and 10 mtttr ginner looking for usina two 10 tula.s transceiver whirr permanent Instal- and mie 30. An un- made such nai lation, completely usually posrer111, record for A.C. operated, wo bog range batten high gttnlit) recommend this 3 iransreiver possess- sial. Uses ing excellent stabil- ts In 1 balanced com- all SO 2t ti- ity and good modu- bination t r a i l s- put to plates. st reiner. lation. )loran's Push-pull 19 os- Ìdirect from 110 volt A.C. The tubes used are ulator with two 1m. Scutt rit te regener- 1 dual -53 purpose 'lase p u a h -p u 11 ation and volume controls triode. l -NO retu- class It audio Ir on rectpt ion : Mint Ion t 1 e r. Absolutely ,tth sending anti control on hnwless when work- transmission, positions 1 : Ives powerful speaker ii.g 5 and 10 nu.- ivirlitging true 5 trr bauds. Extreme- tube nteption. or automatic nerfortaure. Rat - earphone Jack cuts ont ly sensitive. and ex- teriea used: 3 -95 speaker. This Job Is in a tra ordinary long t',It. anti 2 No. 0 tuning and receiv- try relis. elms by Itself mnong ing range. Complete klt, less transceivers and Is !wonting Complete Nì1 of Parts. less tubes, eabi net, cabinet, tulles, too well known to renuire unwired additional praise by us. un- Wired and Assembled fired.... . t1/.o6 Complete kit, less speaker. tubes anti cabinet. un- Crystallized Cabinet Assemblent. 3.00 wired 511.50 wired Kit of 2 Tubes 1.10 Cabinet and speaker 2.75 Wiring ollagram 1m1 w I 11101 ,ae1i k i' ttinet 1.50 watched tubes 1 -55 Wiring .. 3.50 3 tubes I.6n

SREETM RADIO CONSTRUCTORS LABS. RAP DEPT. NEW

www.americanradiohistory.com WILL HELP YOU START A SPARE TIME OR FULL TIME RADIO SERVICE BUSINESS I. E. Smith President National Radio Institute WITHOUT CAPITAL One million dollars is being spent on two sta- Free Book Tells How. tions. Receiving sets are being designed and built. New opportunities -many of them -are Mail Coupon! right ahead. My book tells you of the opportunities in these fields, also in aviation Radio, . sets for home The world -wide use of police Radio, short wave Radio, automobile entertainment has made mat* opportunities for time Radio Radio and other new branches of this fast grow- you to have a spare time or full Get it. HERE ARE A FEW EXAMPLES service business of your own. The day you en- ing industry. roll I start sending you Extra Money Job Sheets OF THE KIND OF MONEY which quickly show you how to do Radio repair jobs common in most every neighborhood. Many I Train You at Home N. R. I. men make $5. $10, $15 a week extra in I TRAIN MY MEN TO MAKE spare time while learning. I show you how to in Your Spare Time all types of receiving sets. I install and service Hold your job until your e ready for another. give you Radio equipment and instructions for building circuits Give me only part of your spare time. You do conducting experiments for not need a high school or college education. and testing equipment, and for making tests that Has Business Radio experience. Hundreds with only a common school education Now Fine will give you broad practical through N. R. I. Graduate below and my free 64 -page have won bigger pay "I have a fine bu .iness servicing Clip the coupon get jumped from $35 to $100 a week. in gives you a J. A. Vaughn sets. I am making a good living-sel- book, "Rich Rewards Radio"-it Fred Dubuque doubled his earnings in one year. full story of the success of N. R. I. students and dom have a week under $40. If it spare The National Radio Institute is the Pioneer and N. R. 1., I would graduates, and tells how to start a time devoted wasn't for probably business on money World': Largest organization exclusive- be tramping the streets. or full time Radio service ly to training men by Home Study for good Glenn C. King, made in spare time while learning. jobs in the Radio industry. 46 Division Ave., S., Grand Rapids, Mich Many N. R. I. Men Make You Must Be Satisfied $15 a Week in Spare Time $5, $10, 'tea a Week Extra I will give you an agreement to refund every penny of your money if you are not satisfied "My spare time earnings average in Spare Time While Learning with my Lesson and Instruction Service when $15 a week. Since studying with you complete my Training. And I'll not only you I have earned about $7,000 to Many of the twenty million sets now in use give you thorough training in Radio principles. $8,000 in Radio. I owe my success are less than 50'% efficient. I will show you how practical experience in building and servicing R. you to the good method of the N. I." to cash i on this condition. I will show sets, but also Advanced Specialized Training in C. N. Heffelfinger. the plansn and ideas that have enabled many the type of Radio work you choose. R. F. D. No. 1. others to make $5. $10, $15 a week in spare Temple, Penna. time while learning. George W. Honert. 248 Water St., Ligonier, Ind.. made over $600 from the tart of the Course to its completion. Get My Free Book of Facts Best Equipped Shop in Town Mail the coupon for "Rich Rewards in Radio." It's free to any ambitious fellow over 15 years "In the last year, we have moved old. tells you about Radio's spare time and our Radio shop and we now have Get Ready Now for a Radio It full time opportunities ; about my training; the best equipped Radio Repair Shop Business of Your Own and what others who have taken it are doing and in East Toledo. We also have a making. Mail coupon now +hop at 624 Milton Street. We or paste have three fellows working us." for Jobs Like These in an envelope, for it on a lc post card. W. R. Brown, engineer.. operators, 309 Main St., Broadcasting station- station managers, and pay up to $5,000 a year. J. E. SMITH, Pres. Toledo, Ohio. inspectors, Radio manufacturers use testers, Dept. 6GB3 foremen, engineers. servicemen and buyers and pay up to $6.000 a year. Radio dealers and job- National Radio You Get PRACTICAL EXPERIENCE bers employ hundreds of servicemen, salesmen, managers. and pay up to $75 a week. Television I nstitute with Radio Equipment I Give You promises many good jobs soon. Television is leaving the laboratory in an impressive way. Washington, D. C. Ji I'll show you how to -. .cial lts,Ij. ,quip r nient for conducting .,,,,vitavots and 1. iii ling circuits which Ilhtstrat, uurva loot principivs used In such well -known sot. as %vestinghouse. .meat! Electric, l'alleo. R.I'. A., Vlet r. Atwater-Kent. mid others. You work out with your own hands many Get My FREE LESSON of the things you read In our lesson books. This 50.11) method of training amkes on Radio Servicing Tips learning nt Inuit... easy, interesting, fascinating. intensely lrae- J. E. SMITH. President. . 1,u 11,1 tIrnI. Yon born how wets work. niono a A'um .r understand that it is just tNot vint to d to Institute, why they work, how to u.n ke lo National Radio thdu. work. mister Itnd lo. \li' sample lesson text. Rund Iteeeiver Troubles -their l'anse mal Remedy Dept. 6GB3, veers a long list of Radio nsei yer troubles In A.C.. 0.1'.. battery, universal. auto, Washington, D. C. snfar- heterodyu,, all -ware, :mil other tykes of wets. And it cross referent, system Leeeu,`ICdamour Without the ci ers you the probable Patin and it quick uny hook sott full time to locate and remedy these set troubles. A Radios opportuenities. how I for tuen, at home sitecinl section Is devilled to receiver cheek -uph in and inn ran train alignment. balancing. neutralising and testing. t ;t this turion Fr, e. So bligatlon. - JUN/ ee eeee e eeeei Nance Aye.-- - COUPON NOW MAIL 1 Address

7uld out about* World Famous Course that Pays for Itself City State 14x1

If you do not want to cut this cover- simply write us on a post card