ABOUT VALVES

Radio Record, Volume I, Issue 25, 6 January 1928, Page 14

ABOUT VALVES

USEFUL ADVICE. Radio valves, like living things, grow old, and finally come to the end of their existence. Formerly," when valves had_ golid tungsten filaments, a valve was. useful until the filaments would no longer light. To-day, however, economical valyes employ special filaments which continue to light even after the valve has become practically useless. So a lighted yalve is no proof that the valve is still good. Progressive radio dealers have valve testers with which to determine the characteristics of valves. When possible the, radio enthusiast should have doubtful valyes tested by his radio dealer and, as often as not, those same valves, provided they have X-IL or thoriated-tungsten filament, can be rejuvenated or reactivated as it is called, so as to deliver several hundred hours of additional service: AN EASY ‘LEST. To the radio listener in rural parts where a local radio dealer is a rarity, there is simple home-nade means for testing the efficiency of valves. ‘This involves nothing more than mere comparisou between a yalye of highest efficiency and the valye in the receiving set. Tirst of ali, the radio enthusiast should secure a new valve from a reliable dealer. ‘This valve is now substituted for one valve after the other in the receiving set. noting the difference in signal strength and tonal duality. In this manner the radio enthusiast or listener can tell which valves are getting weak, causing a loss in, signal Strength and even impairing the tonal qualitv, by direct comparison. Reliable valyes have a life well in excess of a thousand service hours, I‘urthermore, while efficient valves should be emploved for the audio amplifier sockets, the older valves can be used with good resuits for the radio frequency and detector sockets, en 8 tee er ene