Broadcasting (July - Dec 1936)

COVERAGE SERVICE WILL BE EXPANDED EDGAR H. FELIX, of New Rochelle, N. Y., announces that his Radio Coverage Reports service is to be the foundation of a national system of rating radio station coverage effectiveness. The first network station ratings, covering 46 cities of more than 100,000 population, have just been released to subscribing advertising agencies, advertisers and broadcasting companies, to be followed soon with figures for hundreds of smaller communities and larger geographical divisions. By these ratings, it is claimed, the reliable coverage attained by any list of radio stations may be compared and evaluated according to the needs of the individual advertiser. Radio Coverage Reports, as originally announced a few months ago, was planned only to analyze radio service to leading trading centers in which approximately 50% of the population reside, but it was soon found that subscribing agencies desired a more comprehensive view of radio coverage. Reports are now issued not only for large cities but for smaller communities and rural places as well, so that the effectiveness of stations can be studied throughout their areas and compared. The service has been issued for some 300 communities from Maine to Florida and as far west as Indiana in counties with a total population of 39,566,689, or 68.4% of the states covered and 32.2% of the total population of the United States. The percentage of radio sets is higher, being 73.5% of those in the area covered and 36.8% of those in the United States, this being due to the larger concentration of sets in cities. Following the issuance of network ratings for various classes of communities will be a state-by-state analysis of urban and rural service by network and independent stations to facilitate compilation of coverage valuations for any combination or grouping of stations for any area covered by the survey. NEW TUBE FOR ULTRA-HIGHS Bell Laboratories Devises Tube Having Two Sets Of Elements Within Single Envelope WPA Theatrical Project To Expand Its Activities EXPANSION of the radio activities of the WPA Federal Theater Project in New York, utilizing sustaining time donated by the stations, is planned by the project's radio division, according to Evan Roberts, its managing director. The New York headquarters are at Broadway and 52d St., where it is proposed to enlarge the staff of players and writers and produce more shows — some to be sent out on the road as touring units like those of Maj. Bowes' amateur hour. Most of the project's programs are dramatizations, all written and produced by its own staff, comprising artists, playwrights and directors on work relief. At present the project has three programs, Pioneers of Science, U-Arts Forum and History in Action, weekly on WHN, a Sunday Shakespearean series on WMCA and Safety Musketeers on CBS each Monday afternoon. Harry Wentworth is casting director, with Frank Curran, A. W. Hoeny and George Asness as directors. PLATE OF TUBE A GRID WIRES OF 4H ARB VISIBLE HERE SHIELD BELL LABORATORIES has designed a new vacuum tube (Western Electric No. 2404) for ultrahigh frequencies which is said to bring nearer the use of high radio power on apex frequencies and to offer possibilities for television. The tube has two sets of elements inside a new type of glass envelope about three inches in diameter and two inches long (see photos). Description of the apparatus was given at a recent meeting of the Institute of Radio Engineers, New York, by A. L. Samuels and N. E. Sowers, of Bell Laboratories. Plans are under way to construct it in larger sizes, with corresponding increase in power output. Push-Pull Arrangement AN OFFICIAL description of the tube's construction and operation follows : "A simple three-element tube of the type used at low frequencies will go into oscillation at high frequencies because of the internal capacitance of the tube. At moderate frequencies this capacitance can be neutralized as in the familiar "neutrodyne" circuit, but this is ineffective at very high frequencies. Another serious difficulty in this range is the fact that the time required for an electron to travel from the grid to the plate is quite comparable to the duration of one oscillation. "A large number of electrons will then be drawn up to the grid while it is positive, will pass through it and be repelled toward the plate while the grid is negative. The energy for this action on the electrons must come from the grid circuit, and since the grid circuit is one of high impedance, a serious loss in grid voltage will ensue. In the limiting case, the grid voltage falls so low that the system ceases to operate. This effect is minimized, first, by speeding up the electrons through the use of high voltages, and second, by spacing the tube elements very close together. The capacitance of the tube is neutralized by the addition of a screen grid. "The 240H tube has two sets of elements mounted inside the same glass envelope. These are connected to the external circuit to form a push-pull arrangement. Elaborate provisions have been made for shielding the two elements and using very short leads from the envelope to the active elements. Very small spacing between elements is provided by careful manufacture and long in SCREEN GRID APEX TUBE — Above are photographs of the new Western Electric No. 240H tube, with elements indicated. At left is a cross-section of the assembly. The tube is three inches in diameter, two inches long. sulation paths to permit high plate voltage. "As a result this tube has an input resistance at 150 million cycles of 30,000 ohms as compared to 1,000 ohms for a typical tube of the conventional type. At 300 million cycles the input resistance of the 240H vacuum tube is still above 5,000 ohms, while for conventional tubes it is so low as to make them completely inoperative. When operating as a class 'A' amplifier at 150 megacycles, an output of one watt is obtained with the distortion 40 db below the fundamental. Under these conditions the stage gain is 20 db. Outputs of 10 watts with a plate efficiency of 60 to 70% and a gain of 20 db are secured with class 'B' operation." KSFO Lease Hearing APPLICATION for voluntary assignment of KSFO, San Francisco, from Associated Broadcasters Inc. to CBS, under a proposed lease arrangement involving approximately $25,000 per year, was set for hearing Oct. 26 by the FCC Broadcast Division. The station on Dec. 29 will become the San Francisco outlet of CBS in lieu of KFRC of the Don Lee Broadcasting System. On that date, KNX, Los Angeles, CBS owned station, joins the network as the Don Lee Network of four stations becomes affiliated with Mutual Broadcasting System. Radio-Film Cooperation For Their Mutual Benefit Is Urged by Aylesworth WORKING arrangements to prevent interference between motion picture production and radio are advocated by M. H. Aylesworth, RKO board chairman, who long has believed that the movies and radio help each other. Mr. Aylesworth is a member of a film . industry committee named to study the radio-film problem, other members being Nicholas M. Schenck and Harry M. Warner. The committee, which also is eyeing television, is expected to report within a week or two. At a meeting held Oct. 14 at Rochester by motion picture engineers, Mr. Aylesworth had the following to say of television: "The entertainment industry is now faced with the development of television, which will be with us in a short time. I for one believe that the motion picture industry should work with those who are developing television so that when the history is written the motion picture, the theatre and television will work for each other and enhance the public interest in all three mediums of entertainment." Mr. Aylesworth suggested that broadcasters should "help develop the slogan for the motion picture and the theatre 'take your family to a motion picture theatre twice a week'." He pointed out that people like to get away from home for outside entertainment and a change from family habits. Dyer WEMP Sales Head COMMERCIAL management of WEMP, Milwaukee 100 watter which operates daytime on 1310 kc, has been taken over by Gene T. Dyer, operator of WGES and WSBC, Chicago, and WCBD, Zion, 111. President of WEMP is Herbert L. Mount, attorney; vice president, Thomas M. Duncan, financial secretary to Gov. La Follette; secretary-treasurer, Glenn D. Roberts, Madison attorney and a director of WIBA, Madison. Mr. Roberts is chief stockholder, with 72 shares, and Mr. Dyer owns 25 shares. Bar Dinner Set THE RECENTLY formed Federal Communications Bar Association will hold its annual dinner Nov. 18 at the National Press Club, Washington, according to an announcement made by its executive committee Oct. 27. Louis G. Caldwell, Washington attorney, is president, Ralph H. Kimball, of New York, vice president, and George O. Sutton, Washington attorney, secretary-treasurer. Arrangements for the dinner are under the immediate charge of Ben S. Fisher, member of the executive committee. Several speakers will be invited. The Association has a membership of 129, comprising attorneys engaged in practice before the FCC. Dr. Strasska Returns DR. STRASSKA LABORATORIES, Los Angeles, manufacturers of tooth paste, on Nov. 2 launched a six-week campaign through the Glassner Advertising Agency, Los Angeles, using the eight stations of the Don Lee-California network for a quarter-hour one night a week with George Fischer's Studio Whispers, gossip of the film studios. Page 42 • November 1, 1936 BROADCASTING • Broadcast Advertising