What output is produced by a balanced modulator?
The correct answer is D: Double-sideband modulated RF. The output produced by a balanced modulator is double-sideband modulated RF. Balanced modulators suppress the carrier and produce only the two sidebands (USB and LSB). For amateur radio operators, this is the first step in SSB generation. Understanding this helps when designing SSB transmitters.
Exam Tip
Balanced modulator output = double-sideband modulated RF. Think 'B'alanced 'M'odulator = 'B'oth 'M'odulation sidebands. Balanced modulators suppress carrier and produce only the two sidebands (USB and LSB). Not FM, not audio, not audio extraction - just double-sideband RF.
Memory Aid
"Balanced modulator output = double-sideband modulated RF. Think 'B'alanced 'M'odulator = 'B'oth 'M'odulation sidebands. Balanced modulators suppress carrier and produce only the two sidebands. First step in SSB generation."
Real-World Application
A balanced modulator: Audio input modulates a carrier, but the carrier is suppressed. The output contains only the upper and lower sidebands (double-sideband, suppressed carrier). This is the first step in SSB generation - next, a filter selects one sideband. Balanced modulators produce double-sideband output.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Balanced modulators don't produce frequency modulated RF - they produce amplitude-modulated sidebands, not FM. FM is different.
Option B: Incorrect. Balanced modulators don't produce audio with equalized frequency response - they produce RF sidebands, not audio. Audio equalization isn't the output.
Option C: Incorrect. Balanced modulators don't extract audio from modulation signal - they produce RF sidebands. Audio extraction is for receivers, not modulators.
题目解析
The correct answer is D: Double-sideband modulated RF. The output produced by a balanced modulator is double-sideband modulated RF. Balanced modulators suppress the carrier and produce only the two sidebands (USB and LSB). For amateur radio operators, this is the first step in SSB generation. Understanding this helps when designing SSB transmitters.
考试技巧
Balanced modulator output = double-sideband modulated RF. Think 'B'alanced 'M'odulator = 'B'oth 'M'odulation sidebands. Balanced modulators suppress carrier and produce only the two sidebands (USB and LSB). Not FM, not audio, not audio extraction - just double-sideband RF.
记忆口诀
Balanced modulator output = double-sideband modulated RF. Think 'B'alanced 'M'odulator = 'B'oth 'M'odulation sidebands. Balanced modulators suppress carrier and produce only the two sidebands. First step in SSB generation.
实际应用示例
A balanced modulator: Audio input modulates a carrier, but the carrier is suppressed. The output contains only the upper and lower sidebands (double-sideband, suppressed carrier). This is the first step in SSB generation - next, a filter selects one sideband. Balanced modulators produce double-sideband output.
错误选项分析
Option A: Incorrect. Balanced modulators don't produce frequency modulated RF - they produce amplitude-modulated sidebands, not FM. FM is different. Option B: Incorrect. Balanced modulators don't produce audio with equalized frequency response - they produce RF sidebands, not audio. Audio equalization isn't the output. Option C: Incorrect. Balanced modulators don't extract audio from modulation signal - they produce RF sidebands. Audio extraction is for receivers, not modulators.
知识点
Balanced modulator, Double-sideband, Modulated RF, SSB generation
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.