Radio mirror (Jan-Oct 1923)

RADIO DIGEST ILLUSTRATED REBUILDING OF WBZ STRENGTHENS VOICE SURMOUNTS ETHER BAR TO ALL NEW ENGLAND Improved Springfield Station Uses Two Oscillators and Three Modulators of 250 Watts Each By B. F. Kin? Jlany Kadiophans have doubtless noticed that the voice of WBZ, the Westinghouse station at Springfield, Mass., is considerably louder and clearer than it was last winter. There is a good reason for this improvement. The station was entirely rebuilt during the summer and is now one of the finest in the country. The original station was opened in September, 1921, and was one of the pioneers in the broadcasting field. Only two or three stations now in operation have a longer period of operation record. WBZ was designed to serve New England only, so that its power was limited. But, though it was found to have a consistent range of about 500 miles south and west under good atmospheric conditions, it did not entirely fulfill its purpose. All New England. Hard to Beach New England is peculiar from a Radio standpoint, and for some unknown reason there were several areas in this section that WBZ could not reach. The new station, however, has remedied this situation and now can be heard clearly on a detector tube alone all over the northeastern part of the country. The new transmitting apparatus is of the same type as that used by Stations KDKA, KYW, and WJZ, although somewhat smaller. It has two oscillating tubes and three modulator tubes, each rated at 250 watts. Ten-volt alternating current for tjie filaments is supplied by a transformer from a 110-volt circuit, and 2000volt direct current for the plates is supplied by a motor-generator set located outside of the station and remotely controlled from the transmitter. The tubes are kept cooled by a fan mounted behind the transmitter. Antenna on 142-Foot Towers The transmitting antenna is supported by two structural steel towers, 142 feet high. These towers are located on the roof of the company's Radio factory so that the height of the antenna above the ground is 200 feet. The antenna is made up of six phosphor-bronze cables spaced five feet apart and is 220 feet long between insulators. A counterpoise, of similar dimensions, is suspended 130 feet below the antenna. Special arrangements have been made to prevent breakage of the antenna and counterpoise by ice, and a heavy current can be circulated through the antenna wires and down leads to prevent accumulations during ice storms. Shirred Monk Cloth Cuts Out Echoes The studio, which is located on the third floor of the building, is a room of 20 by 23 feet. Heavy carpets on the floor and shirred monk cloth on the walls and ceilings eliminate all echoes. Among the musical instruments used are a KnabeAmpico reproducing grand piano, a Victrola, and a Brunswick talking machine. The condenser type microphone, which is standard at present, is hung from a movable and adjustable stand. Its output passes through three stages of amplification before it goes to the transmitting room, where three more stages of amplification are provided. The studio amplifiers are housed in a cabinet padded with felt. A small receiver with a loop aerial is used to check the character of. the performances broadcast. Schedule of Operation WBZ operates every night from 7:30 to 9 P. M. Eastern time. Its regular weekly program includes children's stories, agricultural reports, addresses, and music. On Sunday, chapel services are broadcast at Z P. M. and church services at 8 P. M. A number of well-known people have addressed the Radio audience from WBZ, including the governor of every New England state, and Dr. Charles P. Steinmetz. It is stated that more than 2,000 hours of operating time, conservatively estimated to be worth $150,000, has been saved to navigation interests in the Great Lakes in a single season by Radio advice as to weather conditions. Carter " TV WA Y" Radio Plug take two head sets and all types cord tip terminals. Price $1.50. Write for Bulletin on Car ter "HOLD-TITE" Jacks and other products CARTER RADIO COMPANY, 209 South Slate Street, CHICAGO THE ONLY KNOB and DIAL WITHOUT A SET SCREW ASK YOUR DEALER "*->=. 4 in., $1.50 3 in., $1.00 'NOB & DIAL CO., Inc. eet NEW YORK CITY Growth in Radio Interest Keeps Uncle Sam's "Lab" Staff on Jump Information Service Installed for Fans, Experimental Investigations Conducted, Radio Relay Perfected, Improvement Made in Various Outfits as Part of Bureau of Standards Work WASHINGTON. — During the past year there has been a remarkable increase in popular interest in Radio communication, according to Dr. S. W. Stratton, former chief of the Bureau of Standards. Dr. Stratton continues in part: "This has been greatly stimulated by the fact that there has become available Radiophone apparatus of satisfactory performance, by means of which market and crop reports and other news, music, and entertainments have been transmitted broadcast and received by many persons. This general interest has resulted in a large increase in the bureau's correspondence on Radio subjects. Dozens of letters asking for Radio information are received each day, and many of these are of considerable importance. Badio Information Service Required "In order to answer such inquiries, as well as to keep the bureau's staff informed on current developments, it has been necessary to devote much time to the maintenance of a Radio information service. An unusually large number of visitors have called at the Radio laboratory, and in order to avoid continual interruption of the regular work in progress special arrangements have been made for demonstrating the exhibits of most general interest. Members of the bureau have delivered a number of lectures on Radio subjects. Electron-Tube Generator Research. "Theoretical and experimental investigations were conducted on the power output of electron-tube generators. A paper was prepared for publication on methods of testing and rating electron-tube generators. A special form of electron-tube generator was developed for producing sparks of high frequency for use with recording apparatus for recording the pressure cycle in a gas engine cylinder. Work on Badio and Audio Amplifiers "Special amplifiers, using both Radio frequency and audio frequency amplification, were developed for particular purposes, including direction finding, Radiophone communication with surfboats of the Coast Guard service and reception of material sent broadcast by Radiophony. "A 5-stage amplifier was developed which used 60-cycle alternating current to supply power for the filaments and plates, instead of the usual storage and dry batteries. Both Radio frequency and audiofrequency amplification are used in connection with a crystal detector. This amplifier has aroused considerable interest, and is described in a paper which has been published. A special amplifier was developed for amplifying variations in direct current, or low-frequency alternating currents. Badio Belay Perfected "A Radio-operated relay has been developed which employs audio frequency tuning and has been found effective for operating other mechanisms. Such a relay can be used for the remote control of BALDWIN Master Type Dealers: New Discounts Hudson-Ross, 123 W. Madison, Chicago 1UAGNJWOK JKl Sladid Dfie Reproducer Suprem® IN Radio, there are no substitutes for the Magnavox electrodynamic principle. When you purchase Magnavox apparatus you assure yourself the utmost satisfaction. R»2 Magnavox Radio with 18-inch horn (as illustrated) Forstore demonstration, large audiences, dance halls, etc. . $85.00 R-3 Magnavox Radio with 14-inch hotn For homes, offices, amateur stations, etc. $45.00 At gooddealers everywhere The Magnavox Co Oakland, Cal. mechanisms by Radio. The relay is rugged and highly selective, and is very useful when moderate strays or considerable interference exists. By proper audio frequency tuning it has made clear tape records of messages when interference was so severe that an experienced operator could not copy the message at all by the use of his phones. It can be used for reception at fairly high speeds. Relays of this type have been constructed for various applications in the Signal Corps and other branches of the Government service. Equip Surfboat; Communicate Five miles "At the request of the Coast Guard, Radiophone transmitting and receiving equipment was installed on a 36-foot motor-driven surfboat, and successful communication in both directions was maintained during a demonstration over a distance of about 5 miles from shore. "The antenna used on the boat was a single-turn coil antenna, of which the hull of the boat formed a part. A special multistage amplifier was constructed for use in this work. Pind Better Alcohol for Arcs "An investigation was conducted to determine the most satisfactory denaturing formula for alcohol used to supply hydrogen in the arc chamber of small arcs, and several kinds of denatured alcohol were found which gave more satisfactory operation than ethyl alcohol, which was used as a comparison standard. Preliminary developments were made on a short-wave arc using electrodes submerged in alcohol. "Improvements were made in a method of locating an airplane in flight transmitting Radio signals. Two trucks equipped with crossed-coil direction finders were used, and results of satisfactory accuracy were obtained. Other work has been done on direction finding and related problems for the Air Service. Test Makes of Receiving Sets "A comprehensive investigation has been made on the construction, design, and performance of representative types of Radio receiving sets. Methods of testing RADIO MAILING LISTS 12,400 Radio Dealers, i-overine U. S. by statee Per M $ 7. 50 1,614 Radio Mfr,.. coverine U.S. by states. PerliBt 15.00 1.757 Radio Supply Jobbers, coverinE U. S. by states. Per list 15. 00 260 'Radio Stations Pe: Ii?t 4.00 257 Mfre. who make and assemble complete Radio Sets Per list 4.00 25,000 Radio Amateurs & Mfrs. of Radio Stations. Per M 7. 50 Ask for price list covering Canada and England. Send remittance with orde . Trade Circular Addressing Co.. 16G W. Adams St., Chicago, III. and standards of performance have been developed for receiving sets, and publications covering various classes of sets are in preparation. Some of this, work has been conducted in co-operation with commercial testing laboratories and retail trade organizations. "The -bureau has co-operated with the National Fire Protection Association in the preparation of a revised rule for Radio installations for the National Electrical code." Makes Music on Glasses with Fingers for WEAF NEW YORK. — One outstanding musical novely of the present season broadcast from Station WEAF, of the American Telephone and Telegraph Company, was that of recent date when Charles Wold, famous for his work on musical glasses, gave a special program. For many years Mr. Wold has toured the country with these musical glasses, fifty-two in all. Mr. Wold wets his fingers and by rubbing over the edges of the glasses, which contain no water, the skill of his touch produces music of exquisite sweetness. Isaak Newlin, an Alaskan Eskimo, in his early twenties, is a Radio operator of marked ability. FOR YOUR RADIO Saves you 50% of the usual coat and you get an unconditional WRITTEN 2 YEAR GUARANTEE Best battery buy on the market to* day. Thousands of satisfied users. e-Voit 40 Amp. 'SIEIIcVaVIO^ 6 voit *« 950 6-voit $4 4.50 WAmp. J.4&=:|| 100 Amp. **»== AtA mboat our rubbtr container* WORLD BATTERY CO. 60 E. Roosevelt Rd. — Dept L. CHICAGO, ILLS. New York Of 370 Seventh Ave, 44T X J HEN happi V V ness °r ca" lamity is about to come, it can be known beforehand." — said Confucius. Insure complete Radio happiness with a Grebe Receiver. Licensed under Armstrong TJ. S. Pat. No. 1113149 A. H. GREBE & CO., Inc. Richmond Hill, N. Y. DELICATE SOLDERING Both the manufacturer's and amateur's problem on all fine work is readily solved by the instrument constructed for this particular purpose. A\ The Post Soldering Iron Platinum Heating Unit Interchangeable Tip Universal Current MSTS $6.00 ONE-HALF ACTUAL SIZB Awarded Certificate of Excellency. N. T. Evening Mall Badio Institute From your dealer or write $6.00 POST ELECTRIC COMPANY, D«" S'eV?or£""1s