Which of the following filters is used in a 2-meter band repeater duplexer?
The correct answer is B: A cavity filter. Which of the following filters is used in a 2-meter band repeater duplexer is a cavity filter. Cavity filters are used in repeater duplexers. For amateur radio operators, this is important for repeater design. Understanding this helps when working with repeaters.
Exam Tip
Filter in 2-meter repeater duplexer = cavity filter. Think 'C'avity 'F'ilter = 'C'ommon in 'F'repeater duplexers. Cavity filters are used in repeater duplexers. Not crystal filter, not DSP filter, not L-C filter - just cavity filter.
Memory Aid
"Filter in 2-meter repeater duplexer = cavity filter. Think 'C'avity 'F'ilter = 'R'epeater duplexer. Cavity filters are used in repeater duplexers. Important for repeater design."
Real-World Application
A 2-meter band repeater duplexer: A cavity filter is used. Cavity filters provide the high selectivity needed to separate transmit and receive frequencies in a duplexer. This is the filter - cavity filter for repeater duplexers.
Key Concepts
Why Other Options Are Wrong
Option A (Crystal filter): Incorrect. Crystal filter isn't used - cavity filter is used in 2-meter repeater duplexers. Crystal filter isn't the answer.
Option C (DSP filter): Incorrect. DSP filter isn't used - cavity filter is used in 2-meter repeater duplexers. DSP filter isn't the answer.
Option D (L-C filter): Incorrect. L-C filter isn't used - cavity filter is used in 2-meter repeater duplexers. L-C filter isn't the answer.
题目解析
The correct answer is B: A cavity filter. Which of the following filters is used in a 2-meter band repeater duplexer is a cavity filter. Cavity filters are used in repeater duplexers. For amateur radio operators, this is important for repeater design. Understanding this helps when working with repeaters.
考试技巧
Filter in 2-meter repeater duplexer = cavity filter. Think 'C'avity 'F'ilter = 'C'ommon in 'F'repeater duplexers. Cavity filters are used in repeater duplexers. Not crystal filter, not DSP filter, not L-C filter - just cavity filter.
记忆口诀
Filter in 2-meter repeater duplexer = cavity filter. Think 'C'avity 'F'ilter = 'R'epeater duplexer. Cavity filters are used in repeater duplexers. Important for repeater design.
实际应用示例
A 2-meter band repeater duplexer: A cavity filter is used. Cavity filters provide the high selectivity needed to separate transmit and receive frequencies in a duplexer. This is the filter - cavity filter for repeater duplexers.
错误选项分析
Option A (Crystal filter): Incorrect. Crystal filter isn't used - cavity filter is used in 2-meter repeater duplexers. Crystal filter isn't the answer. Option C (DSP filter): Incorrect. DSP filter isn't used - cavity filter is used in 2-meter repeater duplexers. DSP filter isn't the answer. Option D (L-C filter): Incorrect. L-C filter isn't used - cavity filter is used in 2-meter repeater duplexers. L-C filter isn't the answer.
知识点
Filters, 2-meter band repeater duplexer, Cavity filter
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.