Radio age research, manufacturing, communications, broadcasting, television (1941)

NEW TUBE DETECTS LEAKS IN VACUUMS MICROSCOPIC leaks in the vacuum systems of cyclo- trons, electron microscopes, refrig- eration equipment, electron tubes, and vacuum stills can now be located quickly and simply by means of a new, portable leak locator developed by the Tube Department of the Radio Corporation of America. Operation of the unit depends on an ingenious tube of the ionization- gauge type which is sensitive only to hydrogen gas. In operation, the gauge tube and the device under test are connected into a vacuum system and a fine jet of hydrogen played over the areas suspected of leakage. Any openings, no matter how small, will suck in hydrogen which quickly reaches the gauge tube. The latter features a small plate of palladium which when hot allows hydrogen but no other gases to pass through into the tube thereby creating a change in the operating characteristics of the tube. This change is indicated on a sensitive meter. In .several years of factory tests, the indicator has been successful in locating tiny leaks in many types of vacuum tubes. When a small unex- hausted electron tube is tested, its exhaust tube is plugged directly into the leak detector before the air has been exhausted from the tube. A rotary vacuum pump is then used to establish a vacuum throughout the system, including the tube under test. Next, a hood is lowered over the tube and filled with hydrogen gas. If a leak is present in the tube, even though so minute that mole- cules of air can barely pass through, seepage of the hydrogen will show on the meter. This procedure merely demonstrates the presence of a leak. To locate the faulty spot exactly, the hood is removed and a fine jet of hydrogen played slowly over sus- pected areas until a movement of the meter marks the leak. The leak detector weighs only 25 pounds complete and can be handled THIS DETECTOR ISIM. XKW VACUUM GAUGE TUBE LOCATES LEAKS SO SMAU, THAT MOLECULES OF AIR CAN SCARCELY PENETRATE THROUGH OPENINGS. by non-technical personnel. RCA has developed several other types of vacuum-gauge tubes of ex- treme sensitivity. They are used for measuring gas pressures and as pro- tective devices in vacuum systems. HARRY C. KOPF JOHN H. MACDONALD NBC MAKES CHANGES IN EXECUTIVE STAFF REALIGNMENT of the execu- tive organization of National Broadcasting Company, resulting in the naming of three administrative vice presidents and the promotion of other personnel, was announced August 1, by Niles Trammell, NBC president, following a meeting of the network's Board of Directors. Harry C. Kopf, formerly vice president in charge of Sales, was appointed administrative vice presi- dent in charge of Network Sales, National Spot Sales, Owned and Operated Stations and Station Re- lations. George H. Frey was named director of Network Sales. James M. Gaines was named director of Owned and Operated Stations and will continue as manager of station WNBC. Ken R. Dyke was appointed ad- ministrative vice president in charge of Program, Continuity Ac- ceptance and Public Service Depart- ments of the company. Mr. Dyke will continue in charge of Broadcast Standards and Practices. John H. MacDonald, formerly vice president in charge of Finance, was appointed administrative vice president. Mr. MacDonald will have charge of finance and budget mat- ters and in addition, will supervise the following departments: Treas- urer's, Controller's, Personnel, Gen- eral Service and Guest Relations. I. E. Showerman, former man- ager of the Central Division, was elected vice president in charge of that Division. Mr. Trammell also announced the retirement of two executives of the company—A. L. Ashby, vice presi- dent and general counsel, who will continue to act as an advisor to the company on legal matters, and Clar- ence L. Menser, vice president of Production and Program Depart- ments. Henry Ladner was desig- nated acting general counsel of NBC. [30 RADIO AGE]