3180

This tube is a tuning indicator consisting of 3 electroes, 2 short and 1 long, in an atmosphere of neon. It may be used in an A.V.C. receiver, where it gives, in the form of a glow spreading up the cathode (long electrode) , a visual indication of the correct tuning point, which point is indicated by the maximum height and intensity of the glow. It is activated by the rise and fall of the anode currents of the3 A.V.C. controlled variable-mu tubes. In use, a steady voltage of 145-160 is required to mmaintain the striking of the tube , and thiis will rise when the receiver is correctly tuned.

Bayonet-style Ba15D base, electrically equivalent to 3184.