Radio broadcast .. (1922-30)

Recently Issued Patents Wireless Telegraph and Telephone System. Lee De Forest, New York, assignor to DeForest Ra- dio Telephone and Telegraph Co., Jersey City, N. J., corporation of Delaware. Filed July 1, 1924, Serial No. 723,488. Renewed May 11, 1929. No. 1,740,577. Constant Scanning Disc, Charles Francis Jenkins, Washington, D. C., assignor to Jenkins Labora- tories, Washington, D. C. Filed Nov. 5, 1928. Serial No. 317,286. 10 Claims. No. 1,740,654. System of Secret Radiant Telephony and Teleg- raphy. John Hays Hammond, Jr., Gloucester, Mass. Filed Feb. 21, 1924. No. 1,740,859. Controlling Phase Relations Hetween Stations. Harry Nyquist, Milburn, N. Y., assignor to American Telephone and Telegraph Co., Filed Oct. 19, 1927. Renewed Sept. 13, 1929. 5 Claims. No. 1,740,867. Exclusive Radio Transmission and Reception. Frederick K. Vreeland, Montclair, N. J. Filed Sept. 13. 1922. Serial No. 587,909. 6 Claims. No. 1,740.964. Piezo-Elcctric Interference Eliminator. Herman A. Affel, Ridgewood, N. J., assignor to American Telephone and Telegraph Company. Filed July 17, 1926. No. 1,739,494. Radio Receiving Circuits. Ralph K. Potter, New York, N. Y., assignor to American Telephone and Telegraph Company. Filed December 4, 1926. No. 1,739,520. Electrical Transmission Circuits. Horace Whittle, Maplewood, N. J., assignor to Bell Telephone Laboratories, Inc., New York, N. Y. Filed August 30, 1926. No. 1,739,699. Wired Radio System. Albert H. Taylor, Washing- ton, D. C., assignor to Wired Radio, Inc., New York, N. Y. Filed January 23, 1926. No. 1,739- 773. Tuning of High-Frequency Circuits. Wendell L. Carlson, Schenectady, N. Y., assignor to Gen- eral Electric Co. Filed October 4, 1928. No. 1,- 740,331. Light Valve Transmitter. Charles Francis Jenkins, Washington, D. C., assig- nor to Jenkins Laboratories, Washington, D. C. Filed June 25, 1927. Split Switching Gear. Charles Francis Jenkins, Washing- ton, D. C., assignor to Jenkins Laboratories, Wash- ington, D. C. Filed Sep- lembcr 6, 1928. No. 1,740, Arrangement For Eliminat- ing Atmospheric Disturb- ances. Abraham Esau and Friedrich Lange, Berlin, Germany, assignors to Gesellschaft fur Drahtlose Hnrrv 4 Telegraphic m.R.H. Hal- „ "" £„ leschcs, Ufer, Berlin, Ger- Ueach, Mrom- many. Filed July 28, 1925, berg and in Germany Aug. 12, 1924. No. 1,743,124. Picture-Transmitting System. Leonard G. Abra- ham, Brooklyn, N. Y., assignor to American Tel- ephone and Telegraph Company. Filed August 18, 1926. No. 1,743,180. Method and Apparatus for Determining the Prop- erties of Acoustic Materials. Edward C. Wente, New York, N. Y., assignor to Western Electric Company, Inc., New York, N. Y. FUed July 13, 1926. No. 1,743,414. Vacuum-Tube Circuits. Sidney E. Anderson, Maplewood, N. J.. assignor to Western Electric Company, Inc., New York, N. Y. Filed De- cember 24, 1923. Renewed March 16, 1929. No. 1,743,701. Picture Transmission. Herbert E. Ives, Montclair, N. J., assignor to Western Electric Co., Inc., New York, N. Y. Filed August 20, 1925. Re- newed Jan. 13, 1928. No. 1,743,856. Photo-Amplifying System. Richard Howland Ranger, Newark, N. J., assignor to Radio Cor- poration of America. Filed November 18, 1924. No. 1,738,315. Method of and Arrangement for Stray Elimination in Radio Communication. Julius Weinberger, New York, N. Y., assignor to Radio Corpora- tion of America. Filed August 17, 1923. No. 1,738,337. Thermionic Amplifier. Edward Herbert Trump, London, England, assignor to Radio Corpora- tion of America. Filed Dec. 24, 1926, and in Great Britain Jan.9,1926. No. 1,738,408. C. M. Black- urn, National Union Adjudicated Patent (C. C. A. N. Y.) Hazeltine patent. No. 1,533,858, for method and means for neutralizing capacity coupling inaudions, claims 1,2, 5,9,11,1214, and 16 held valid and in- fringed. Hazeltine Corp- oration v. Wildennuth, 34 F. (2d) 635. Patent Suits 1,128.292. E. II. Colpitts, Electric wave amplifier; 1,432,022, R. A. Heising, Circuit connections of electron-discharge apparatus; 1,483,273 D. G. Blattncr, Circuit for heating the fila- ments of audions; 1,493,595, same. Amplifying with vacuum tubes; 1,504,537, H. D. Arnold, Power-limiting amplifying device; 1,544,943 E. O. Scribcn, Electric wave repeater for multiplex transmission, D. C., N. D. Ohio (W. Div.), Doc. E 997, Western Electric Co., Inc., et al. v. Silverphone Corp. Decree pro convesso (notice Sept. 20, 1929) 1,173,079. E. F. Alexanderson, Selective tuning system; 1,251,377, A. W. Hull, Method of and means for obtaining constant direct-current potentials; 1,313,094, I. Langmuir, System for amplifying variable currents, D. C., N. D. Ohio (E. Div.), Doc. 2692, Radio Corporation of America, et. al., v. The Sparks-Withington Co. Discontinued without prejudice Sept. 19, 1929. 1,183,875. R. V. Hartley, Electrical circuit; 1,231,764, F. Lowenstein, Telephone relay; 1,349,252, H. D. Arnold, Method of and means for utilizing thermionic currents; 1,403,475, same, Vacuum-tube circuit; 1,432,022, R. A. Heising, Circuit method connection of electron- discharge apparatus; 1,465,332, same, Vacuum- tube amplifier, D. C., N. D., Ohio (E. Div.), Doc. 2691, Radio Corporation of America, et. al., v. The Sparks-Withington Co. Discon- tinued without prejudice Sept. 19, 1929. 1,231,764 (b) F. Lowenstein, Telephone relay; 1,493,217, R. C. Mathes, Vacuum-tube circuit, D. C., N. D. Ohio (W. Div.), Doc. E 1000, Western Electric Co., Inc., et al., v. Silver- phone Corp. Decree pro coufesso (notice Sept. 20, 1929). 1.244.216. I. Langmuir, Electron-discharge appara- tus, and method of preparation; 1,244,217, same, Electron-discharge apparatus and method of operating same; 1,529,597, same, electron-emitting device and method of preparation, C. C. A., 3d Cir., Doc. 3800, General Electric Co. v. The DeForest Radio Co. Decree affirmed Oct. 3, 1929. 1.244.217, I. Langmuir, Electron-discharge appara- tus and method of operating same, C. C. A. 3d Cir., Doc. 3801, The DeForest Radio Co., v. General Electric Co. Decree affirmed Oct. 3, 1929. 1,558,436.1. Langmuir, Electrical discharge appara- tus and the process of preparing and using same, C. C. A., 3d Cir., Doc. 3799, General Electric Co. v. The DeForest Radio Co. De- cree affirmed Oct. 3, 1929. THE SERVICEMAN'S EQUIPMENT (Continued from page 269) stations which file these records will find them to be of inestimable value in follow- ing up such service calls, since a record is available of the kind of set which was serv- iced and how it functioned at that time, and a call in six to eight months will fre- quently result in a second request for ser- vice, which will probably result in the sale of a new set of tubes, at least. One must not forget the psychology of a serviceman entering a home with proper equipment. Shooting trouble, as we did in the old days with a screwdriver and a pair of pliers, pulling this and pushing that to see what happened, simply is not accepted to-day by the consumer who knows he will later be billed several dollars for the oper- ations of the so-called expert. However, when the serviceman shows up with a kit of instruments and proceeds to make an analysis of the entire radio set in a logical and methodical manner, it cannot help but react on the man who pays the bills and cause him to feel he has received his money's worth, even though all that was needed was a set of tubes. The serviceman who is making money to-day is the man with proper equipment. The service department may be an asset or a liability. It is sure to be a liability if much time is spent analyzing minor defects. But, if the serviceman can make eight to ten calls a day, analyze the trouble rapidly and ac- curately, and display his equipment to such advantage that the customer senses his knowledge of the facts, then sales of new tubes should result in velvet in addi- tion to a net profit when the accounts of the service department are totalled at the end of the year. POLYMET RESISTANCES Built to those high standards which have led 80% of the leading radio set manufacturers to adopt POLYMET PRODUCTS CARBON VOLUME CONTROLS WIRE-WOUND VOLUME CONTROLS DUAL CARBON AND WIRE VOLUME CONTROLS SLIDING CONTACT TUBE RHEOSTATS TAPPED VOLTAGE DIVIDERS WIRE-WOUND TUBULAR RESISTORS FLEXIBLE RESISTORS FLAT STRIP RESISTORS GRID LEAKS POLYTHOLS Ask for leaflet No. CL-1, giving diagrams of popular circuits including automobile radio receiver. A catalog ofPolymet Parts is available on application. POL.YOTET JVIFG. CORP. Paper and Mica Condensers — Resistors Electrical Coil Windings — Magnet Wire 837 East 134th Street NEW YORK CITY, N. Y A Radio Parts Guide THE NEW Catalog Send for it today for complete listings of Radio Convenience Outlets, Connector Plugs, Rheostats,Fixed and Grid Resistances, Jacks, Jack Switches, Phone Plugs, etc. YAXLEY MFG. CO. Dept. B, 1528W Adams St., Chicago, 111. LEARN RADIO In a school with a reputation for gra- duating competent men Dormitory— Laboratory— Workshop Subjects Taught: COMMERCIAL RADIO RADIO SERVICE RADIO BROADCAST NAVIGATION RADIO MATHEMATICS LABORATORY VITAPHONE-MOVIETONE Write for further information COMMeRClAL RADIO INSTITUTE BALTIMORC, MIX 38 W. BIDDL6 ST. • • RADIO BROADCAST FOR MARCH • 297