Page 18 Advertisements Column 1

Timaru Herald, Volume CXL, Issue 20261, 9 November 1935, Page 18

Warning to Oladio &uHier6 and C&uu&Pi METAL VALVES SOME racism SHOULD KNOW 1%/TUCH discussion lias arisen as to whether metal valves or glass tubes are the best for modern radio reception. Radio owners and prospective buyers are naturally interested in the respective merits of the two forms of valve, and the following information is therefore timely. Firstly it should be noted that the new metal valves «are much smaller and must operate at a higher temperature, which is not only detrimental to tube life, but changes the characteristics of nearby coils, resistors, etc. This impairs the delicate balance of all the various parts of a radio, which is absolutely necessary for fine performance. Further, with the smaller metal valves, a greater number would be required to give the desired performance, which would demand more tube space. The inability to see inside a metal valve is a distinct disadvantage to the owner, as he cannot tell whether the valves are functioning correctly. With glass tubes the owner can see at a glance whether the tubes are working. Metal valves require twice as many vacuum seals as glass tubes. An air leak in a metal valve at any one of the sealing points would stop the radio from working, while in glass tubes loss of vacuum is practically unheard of. Glass tubes are today practically foolproof—their rugged, ness is attested to by the fact that they do not suffer injury in transportation and handling. High efficiency glass tubes are available in every conceivable single and multiple function type —metal valves are not. In short-wave reception experience shows glass tubes to be ideal. The main requisites in handling short-waves are good dielective properties and good insulation. Glass is inherently a good dielective and a good insulator, whereas metal is definitely not. CONSOLE; MODEIL 97X Philco's latest and greatest all-wave set. Metal Valves Cost Practically Double the Price of PHILCO High Efficiency Tubes. While a metal radio tube might develop possibilities in the future, it is today still in an experimental stage, and while the metal radio tubemight be of some interest to the public because of the novelty of the idea, its disadvantages are far greater than its present advantages. “PHILCO,” the world’s largest-selling radio, is equipped with high efficiency Glass Tubes throughout—and PHILCO is unsurpassed for glorious tone —pure, rich and perfectly natural. For real entertainment—for real music—for real world-wide reception, choose one of the marvellous PHILCO Models. PHILCO Sole N.Z. Agents for Philco: range for a Free Philco GLASS TUBES in your home improve the performance oj CHARLES BEGG AND CO., LTD., STAFFORD STREET AND ARCADE, TIMARU.