Indianapolis Times, Volume 36, Number 260, Indianapolis, Marion County, 12 March 1925 — Page 20

RADIO MONOPOLY COMPLAINTiOBE AIRED NEXT WEEK Importance of Federal Trade Commission Hearing Declared Vital. By THOMAS STEVENSON WASHINGTON, March 12.—1 m portance of the hearings which will begin in New York, March 18, on the complaint of the Federal Trade Commission charging eight companies with an attempted monopoly In the radio field cannot be over-esti-mated. Untold benefits or damages may result ftim them. The compt tint is based primarily' on the patent situation and the crossagreements among the eight companies. Cross-Word Puzzle The trouble arises over existence of more than a thousand radio patents, ownership of which is scattered among many companies. Some of the patents are absolutely essential for the construction of a set while Others are practically valueless. Prior to the entrance of the United States Into the World War. a number of inventions covered by patents, could have been utilized in the manufacture of a large portion of modern radio apparatus, and also numerous Inventions covering various systems could have been employed In rendering a more efficient transoceanic radio communication service. These patents were, however, controlled by Opposing interests who refused to license one another. During War v Asa result of Government appeal during the war the concerns owning the patents disregarded all patent rights and engaged in the manufacture of radio apparatus and devices for the Government, upon the Government’s guarantee to protect them against all infringement suits. Regardless of the outcome of the hearings, it can safely be predicted that they may revolutionize the industry. Unquestionably they will be followed with the greatest Interest by all with whom radio has become so Important, (Copyright, 1925, by Stevenson Radio Syndicate) * INDIANAPOLIS RADIO SCHOOL lews radio ax a profusion or hobby NIGHT SCHOOL COURSE Call or Writ* P. O. DEEDS W Maple Rond Boulevard Phone, WAah. 1*43.

Cradey, Day Fan and Week Rite Neotrodya# Receiving Sets Cunningham Tubes. Manhattan, Herald, Thorofai sad Thoropborte Load Speakers. Rrta, Frost, Bernier, Bremer Tufly, Burge—and many other weO known Radio Prodocta. Cooper BAIHO^andoMITEBIES BMIWIi Map M M mm Mta iiaft mat prUm ? ip - .r The L J. Cooper Rubber Company \ Capital Aim mi Vonamt Si /

Route of Waves Through Broadcasting Station BROADCASTING STATIOtf RECEIVING SET T .cAwuEe "J N \vS \\\ ' f Mxr |7ctector) f I sileilt mooIIarj) ,I\ \ \ jz£~r :.r: 1 1*? 1 ! t £555• J 1 j e = =^ , ■ i f ' • ■"■■, r— — '■■■'' .f— .f— i ( *■ 1 , CONVWTIO 6WCRATCD If MOCULATTD (RAWOriWtICYj (AUWO-fRCOOCIICY) INTO 30UN0 DIAGRAM OF WHAT HAPPENS IN BROADCASTING.

What happens in a broadcasting station, and how the waves travel from the speaker in front of the microphone to your loud speaker, is an Interesting and appealing subject for every one who is interested in radio. When no sound is being made in front of the microphone, the electromagnet energy being sent out over the broadcasting aerial takes the form of a pure sine wave. Thts generated energy cannot be heard if passed through a telephone receiver and c!ln only be beard by a receiver that is oscillating. It then takes the form of the familiar carrier wave whistle. When the announcer begins to speak, the sound waves of his voice are carried over the telephone wires to the radio transmitting station, where they are impressed on the radio frequency or

b'ttefhdto Radio Editor Times: Saturday night I received a station called KFRU in thq State of Oklahoma. Where is it? Tonight I received one, WORD. Where is it located? Your radio section is a great help to me. ALBERT HUFF. 1825 a State Ave. Station KFRU is located Biretow, Okla. WORD is located at Batavia, IIL KFRU operates on a wave length of 296.9 meters and WORD on 275 meters. Radio Editor Times: Can you tell me where Jack Little and Paul Small are broadcasting from this week? INTERESTED FAN. Little and Small are in Clnicnnati this week, broadcasting from the Cincinnati stations.

THE INDIANAPOLIS TIMES

“carrier wave," as It is generated. The contour of the wave form no longer remains uniform, but is broken up into variations and molded into the shape of the waves from the speaker’s voice. This “modulated” current is then forced into the antenna, sending out electro-magnetic waves which have impressed on them “audiofrequency” vibrations of the speaker. These waves travel in all directions until they strike the receiving antenna system. The amount of energy that is "received” is very much smaller than* what is sent out over the broadcasting aerial, but it retains exactly the same wave form as sent out. The received current, when passed through a radio frequency amplifier, still retains Its form but becomes much stronger. The cur-

DIRECTIONS GIVEN DX DEVOTEES FOR AIR ADVENTURING He Is Knight Errant of Ether With Aerial for Scarlet Banner. The DX devotee, when he goes adventuring in the air, must see that his set is fully girded and prepared for the grand hunt. He Is the knight-errant of the ether, but instead of a scarlet banner he sends aloft an aerial, and instead of weapons of the crusader ho is armed with batteries, tubes and condensers. If you would pluck the prizes of the air, here are some of the things to look out for: 1. Good aerial installation. This Involves good insulation at points of support, the proper lead-in insulation and careful planning of the position of both horizontal and vertical portions of the wire with respect to metallic objects in the pronimity of the antenna. 2. The set should be shielded to prevent the effects of body capacity. Without this shield the operator's body, as he touches the tuning controls, forms one plate of a condenser, and permits some of the radio-fre-quency Impulses to leak off to ground. 3. Proper selection of tubes for the circuit used, and proper arrangement of the tubes, which mean changing them from socket to uocket until the best results are heard. 4. Care should be taken that all tuned radio-frequency circuits are in resonance. This may seem a small matter, but the fact is a minute shift of the dial may mean a world of difference in sharply tuned circuits. 5. Batteries should be kept fully charged, so that the set may be at Its highest efficiency and not go dead at the critical moment.

MICROPHONE SENSITIVE Speaker With False Teeth Barred by KGO. Disqualified from speaking over radio KGO because his false teeth made too much noise for the sensitive microphone to igne/e, Fred Mantle, San Francisco landscape gardener, is today considering a silencing grid to be used between the plates. KGO control room operators declared the noise of Fred's mouth crockery sounded like defect in their broadcasting machinery for changing words and music into electrical currents of varying Intensities.

rent then goes through the detector unit, after which It has approximately the form shown as “detected.” The original oscillations have disappeared, and we have instead a current flowing in one direction only, but varying in strength, or pulsating, according to the shape of the sound waves. Without this change in the shape of the wave it would be Impossible to actuate the telephone diaphragms. The current as it comes from the detector is generally not of sufficient strength to operate a loud speaker, so it is passed through an audio frequency amplifier. It now ebcomes strong enough to energize the magnets of the loud speaker, causing the diaphragm to vibrate and send out waves in the air which reproduce, more or less faithfully, those originally created in the studio. Thus Is completed the process which has within a few months transformed us into a Nation of radio enthusiasts.

INDIANA’S LARGEST RADIO HOUSE A Smashing Reduction MAGNAVOX SETS At Prices Within the Reach of Everybody! Broadcast Receiver TRF 50, Was $l5O A five-tube tuned radio frequency receiver consisting of two stages of frequency of special design, detector and two stages of audio frequency. A handsomely covered paneled cabinet contains built-in Magnavox reproducer unit and space for “B” bat. teries. Any standard storage battery or dry cell tubes can be used preferably. Magnavox Type A set is distinguished by single control tuning dial. (Without sllO 00 Complete—Tubes, Aerial AA and Batteries Broadcast Receiver TRF 5, Was sllO Ample space provided for large “B” battery, (Without tubes). 990.00 With Loud Speaker Magnavox Loud Speakers at New Low Prices Magnavox Loud Speaker R-3 Was $35.00 Now s26= Magnavox Loud Speaker M-4, Was $25.00 ff Now $ J o*oo jL Easy Terms If Desired KjhjsdGinnell Cfo Retail Service Wholesale / 33 WEST OHIO STREET—CircIe 6424

STUDY OF RADIO WAVESFOSTERED Eastern School Seeks ‘Dead Spots.’ An exhaustive study of radio receiving conditions in various sections of Philadelphia is to be undertaken by the Moore School of Electrical of the University of Pennsylvania. Investigation will be the basis of a contour map of the city, which will show the comparative signal strengths received In each locality, enabling the fan to tell whether he Is in a good or bad location for receiving. , In addition to determining the socalled “dead spots” in the city, the effect of high buildings will be noted. A small truck fitted out as a receiving station, will move about the city, making tests in all locations. To Test Condenser for “Shorts” The best way to determine whether the plates in a variable condenser toubh each other Is by connecting a ba.ttery and buzzer In series with the condenser. Should be buzzer ojperate with revolving rotary plates It indicates that the plates are touching. A little spark will also be seen at such points, and thus the trouble may be remedied. Another method to be used In locating the trouble is using a pair at phones and B battery connected In the same manner as the buzzer. To Keep Coils Dry A cloth bag containing lime, If it is placed Inside the cabinet, will prevent dampness in coftls or set.