🔍 Key Concepts

• Resonance in an antenna/plate tank circuit (maximum energy transfer at the resonant frequency) • Relationship between plate current and power transfer in a tuned RF final amplifier (class C or similar) • What happens to circulating current in the tank circuit as you tune through resonance

💭 Think About

• When the antenna circuit is at true resonance, is the load on the final amplifier tube closer to its proper design value or farther from it? How would that affect plate current? • Think about a typical "plate current dip" tuning procedure on older transmitters: as you tune the final, do operators look for a peak or a dip in plate current at resonance? • If output power is maximized at resonance for a given plate voltage, what tends to happen to the DC plate current at that precise tuning point compared with slightly off-resonance?

✅ Before You Answer

• Recall that at resonance, the reactive components (inductive and capacitive reactance) cancel, leaving a mainly resistive load to the plate circuit. • Verify in your study materials whether proper tuning of the final amplifier involves adjusting for a dip in plate current and a peak in RF output. • Before choosing, ask: does resonance in the antenna/plate circuit make the final amplifier work harder with more current, or more efficiently with less current for the same output?