What is a characteristic of single sideband (SSB) compared to FM?
The correct answer is C: SSB signals have narrower bandwidth. A characteristic of single sideband (SSB) compared to FM is that SSB signals have narrower bandwidth. SSB uses about 3 kHz bandwidth, while FM uses about 15 kHz. This narrower bandwidth makes SSB more spectrum-efficient and better for weak-signal work, but it can make tuning more critical. For amateur radio operators, understanding bandwidth differences helps explain why SSB is used for weak-signal work and why FM provides better audio quality but uses more spectrum.
Exam Tip
SSB vs FM = SSB has narrower bandwidth. Think 'S'SB = 'S'maller bandwidth (~3 kHz vs ~15 kHz for FM). SSB is more spectrum-efficient. SSB is harder to tune and more susceptible to interference than FM.
Memory Aid
"SSB vs FM = SSB has narrower bandwidth. Think 'S'SB = 'S'maller bandwidth (~3 kHz). More spectrum-efficient than FM (~15 kHz). Main advantage for weak-signal work."
Real-World Application
On a crowded band, SSB's 3 kHz bandwidth allows more stations to operate in the same frequency range compared to FM's 15 kHz. However, SSB requires more precise tuning - being 500 Hz off makes it unintelligible, while FM is more forgiving. The narrower bandwidth is SSB's main advantage for weak-signal and DX work.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. SSB signals are actually harder to tune correctly than FM because the tuning is more critical - being slightly off-frequency makes SSB unintelligible, while FM is more forgiving.
Option B: Incorrect. SSB is actually more susceptible to interference in some ways because it doesn't have FM's capture effect. Strong signals can interfere with weak SSB signals more easily.
Option D: Incorrect. Since A and B are wrong, 'all of the above' cannot be correct. Only the narrower bandwidth is a true advantage of SSB.
题目解析
The correct answer is C: SSB signals have narrower bandwidth. A characteristic of single sideband (SSB) compared to FM is that SSB signals have narrower bandwidth. SSB uses about 3 kHz bandwidth, while FM uses about 15 kHz. This narrower bandwidth makes SSB more spectrum-efficient and better for weak-signal work, but it can make tuning more critical. For amateur radio operators, understanding bandwidth differences helps explain why SSB is used for weak-signal work and why FM provides better audio quality but uses more spectrum.
考试技巧
SSB vs FM = SSB has narrower bandwidth. Think 'S'SB = 'S'maller bandwidth (~3 kHz vs ~15 kHz for FM). SSB is more spectrum-efficient. SSB is harder to tune and more susceptible to interference than FM.
记忆口诀
SSB vs FM = SSB has narrower bandwidth. Think 'S'SB = 'S'maller bandwidth (~3 kHz). More spectrum-efficient than FM (~15 kHz). Main advantage for weak-signal work.
实际应用示例
On a crowded band, SSB's 3 kHz bandwidth allows more stations to operate in the same frequency range compared to FM's 15 kHz. However, SSB requires more precise tuning - being 500 Hz off makes it unintelligible, while FM is more forgiving. The narrower bandwidth is SSB's main advantage for weak-signal and DX work.
错误选项分析
Option A: Incorrect. SSB signals are actually harder to tune correctly than FM because the tuning is more critical - being slightly off-frequency makes SSB unintelligible, while FM is more forgiving. Option B: Incorrect. SSB is actually more susceptible to interference in some ways because it doesn't have FM's capture effect. Strong signals can interfere with weak SSB signals more easily. Option D: Incorrect. Since A and B are wrong, 'all of the above' cannot be correct. Only the narrower bandwidth is a true advantage of SSB.
知识点
SSB vs FM, Bandwidth comparison, SSB characteristics, Modulation comparison
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.