A Screen-Grid Voltmeter and Its Application as a Resonance Indicator

A screen-grid voltmeter of high sensitivity is described and compared with a triode voltmeter. At low frequencies, using either the 222 or the 224 tube, it effectively covers a range of from 0.1 to 10 volts, r.m.s. At frequencies of the order of 10
⁸
cycles per sec., it serves as a supersensitive indicator for a Lecher wire system. For this purpose a tuned input is used.