What is a frequency discriminator?
The correct answer is D: A circuit for detecting FM signals. What is a frequency discriminator is a circuit for detecting FM signals. Frequency discriminators demodulate FM signals. For amateur radio operators, this is important for demodulation. Understanding this helps when working with FM receivers.
Exam Tip
Frequency discriminator = circuit for detecting FM signals. Think 'F'requency 'D'iscriminator = 'F'M 'D'etector. Frequency discriminators demodulate FM signals. Not FM generator, not filter, not band-switching - just FM detector.
Memory Aid
"Frequency discriminator = circuit for detecting FM signals. Think 'F'requency 'D'iscriminator = 'F'M 'D'etector. Frequency discriminators demodulate FM signals. Important for demodulation."
Real-World Application
A frequency discriminator: It's a circuit for detecting FM signals. The discriminator converts frequency variations into amplitude variations (audio). This is what it is - FM detector.
Key Concepts
Why Other Options Are Wrong
Option A (FM generator circuit): Incorrect. FM generator isn't discriminator - discriminator detects FM signals. FM generator isn't discriminator.
Option B (Circuit for filtering closely adjacent signals): Incorrect. Filter for adjacent signals isn't discriminator - discriminator detects FM signals. Filter isn't discriminator.
Option C (Automatic band-switching circuit): Incorrect. Automatic band-switching isn't discriminator - discriminator detects FM signals. Band-switching isn't discriminator.
题目解析
The correct answer is D: A circuit for detecting FM signals. What is a frequency discriminator is a circuit for detecting FM signals. Frequency discriminators demodulate FM signals. For amateur radio operators, this is important for demodulation. Understanding this helps when working with FM receivers.
考试技巧
Frequency discriminator = circuit for detecting FM signals. Think 'F'requency 'D'iscriminator = 'F'M 'D'etector. Frequency discriminators demodulate FM signals. Not FM generator, not filter, not band-switching - just FM detector.
记忆口诀
Frequency discriminator = circuit for detecting FM signals. Think 'F'requency 'D'iscriminator = 'F'M 'D'etector. Frequency discriminators demodulate FM signals. Important for demodulation.
实际应用示例
A frequency discriminator: It's a circuit for detecting FM signals. The discriminator converts frequency variations into amplitude variations (audio). This is what it is - FM detector.
错误选项分析
Option A (FM generator circuit): Incorrect. FM generator isn't discriminator - discriminator detects FM signals. FM generator isn't discriminator. Option B (Circuit for filtering closely adjacent signals): Incorrect. Filter for adjacent signals isn't discriminator - discriminator detects FM signals. Filter isn't discriminator. Option C (Automatic band-switching circuit): Incorrect. Automatic band-switching isn't discriminator - discriminator detects FM signals. Band-switching isn't discriminator.
知识点
Frequency discriminator, Circuit for detecting FM signals
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.