What is the effect on plate current of the correct setting of a vacuum-tube RF power amplifier’s TUNE control?
A pronounced peak
A pronounced dip✓Bonne réponse
No change will be observed
A slow, rhythmic oscillation
Explication
The TUNE control resonates the plate tank circuit, and at resonance a parallel-tuned circuit presents its maximum impedance to the tube, so the current drawn by the plate falls to a minimum. The correct setting is therefore the point of pronounced dip in plate current.