What is the effect on plate current of the correct setting of a vacuum-tube RF power amplifier’s TUNE control?
The correct answer is B: A pronounced dip. The effect on plate current of the correct setting of a vacuum-tube RF power amplifier's TUNE control is a pronounced dip. When the amplifier is properly tuned to resonance, plate current dips to a minimum. For amateur radio operators, this is how you tune a tube amplifier - tune for minimum plate current. Understanding this helps when tuning amplifiers.
Exam Tip
Correct TUNE setting = pronounced dip in plate current. Think 'T'UNE = 'T'ube 'U'nity 'N'ulls current (dips). When properly tuned to resonance, plate current dips to minimum. Not peak, not no change, not oscillation - just dip.
Memory Aid
"Correct TUNE setting = pronounced dip in plate current. Think 'T'UNE = 'T'ube 'U'nity 'N'ulls current. When properly tuned to resonance, plate current dips to minimum. Standard tuning procedure for tube amplifiers."
Real-World Application
You tune a vacuum tube RF power amplifier. As you adjust the TUNE control, plate current changes. When you reach the correct setting (resonance), plate current dips to a pronounced minimum. This is how you know the amplifier is properly tuned. Tune for minimum plate current.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Plate current doesn't peak when properly tuned - it dips. Peak current indicates mistuning.
Option C: Incorrect. Plate current does change when tuning - it dips at resonance. No change would indicate the control isn't working.
Option D: Incorrect. Plate current doesn't oscillate when properly tuned - it dips to a steady minimum. Oscillation indicates instability.
题目解析
The correct answer is B: A pronounced dip. The effect on plate current of the correct setting of a vacuum-tube RF power amplifier's TUNE control is a pronounced dip. When the amplifier is properly tuned to resonance, plate current dips to a minimum. For amateur radio operators, this is how you tune a tube amplifier - tune for minimum plate current. Understanding this helps when tuning amplifiers.
考试技巧
Correct TUNE setting = pronounced dip in plate current. Think 'T'UNE = 'T'ube 'U'nity 'N'ulls current (dips). When properly tuned to resonance, plate current dips to minimum. Not peak, not no change, not oscillation - just dip.
记忆口诀
Correct TUNE setting = pronounced dip in plate current. Think 'T'UNE = 'T'ube 'U'nity 'N'ulls current. When properly tuned to resonance, plate current dips to minimum. Standard tuning procedure for tube amplifiers.
实际应用示例
You tune a vacuum tube RF power amplifier. As you adjust the TUNE control, plate current changes. When you reach the correct setting (resonance), plate current dips to a pronounced minimum. This is how you know the amplifier is properly tuned. Tune for minimum plate current.
错误选项分析
Option A: Incorrect. Plate current doesn't peak when properly tuned - it dips. Peak current indicates mistuning. Option C: Incorrect. Plate current does change when tuning - it dips at resonance. No change would indicate the control isn't working. Option D: Incorrect. Plate current doesn't oscillate when properly tuned - it dips to a steady minimum. Oscillation indicates instability.
知识点
TUNE control, Plate current, Pronounced dip, Vacuum tube amplifier
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.