🔍 Key Concepts
• How changes in resonance and loading affect plate current in an RF power amplifier
• The role of tube condition, bias voltage, supply voltages, and neutralization in controlling current and preventing oscillations
• What parasitic oscillations are and how they influence plate current and stability
đź’ Think About
• For each option, ask: would this condition tend to make the tube draw more current, less current, or stay about the same?
• Think about which factors make the amplifier run "harder" or less controlled: poor tuning, high voltages, low bias, or unwanted oscillations
• Consider whether the listed causes are independent ways that could each lead to excessive plate current, or if some do not really increase current but cause a different kind of problem
âś… Before You Answer
• For each listed cause, mentally trace what happens to plate voltage, grid bias, and current through the tube
• Check your understanding of off-resonance tuning vs. correct resonance: which way does mistuning usually push the current?
• Verify which items (defective tube, loading, bias, voltages, oscillations, neutralization) are known standard causes of excessive plate current in RF amplifiers