Which of these emission modes is best for auroral propagation?
The correct answer is A: CW. Which of these emission modes is best for auroral propagation is CW. CW works best with auroral propagation because it's narrow bandwidth and less affected by auroral distortion. For amateur radio operators, this is important for auroral operation. Understanding this helps when operating auroral propagation.
Exam Tip
Best mode for auroral propagation = CW. Think 'A'uroral 'P'ropagation = 'C'W best. CW works best with auroral propagation because it's narrow bandwidth and less affected by auroral distortion. Not SSB, not FM, not RTTY - just CW.
Memory Aid
"Best mode for auroral propagation = CW. Think 'A'uroral 'P'ropagation = 'C'W. CW works best with auroral propagation because it's narrow bandwidth and less affected by auroral distortion. Important for auroral operation."
Real-World Application
Auroral propagation: CW (Continuous Wave/Morse code) is the best emission mode. Auroral propagation causes signal distortion and Doppler shift, which affects voice modes (SSB, FM) more than CW. CW's narrow bandwidth and simple signal structure make it more tolerant of auroral distortion. This is the mode - CW is best for auroral propagation.
Key Concepts
Why Other Options Are Wrong
Option B (SSB): Incorrect. SSB doesn't work as well as CW - CW is best for auroral propagation. SSB isn't the best.
Option C (FM): Incorrect. FM doesn't work well with auroral propagation - CW is best. FM isn't the best.
Option D (RTTY): Incorrect. RTTY doesn't work as well as CW - CW is best for auroral propagation. RTTY isn't the best.
题目解析
The correct answer is A: CW. Which of these emission modes is best for auroral propagation is CW. CW works best with auroral propagation because it's narrow bandwidth and less affected by auroral distortion. For amateur radio operators, this is important for auroral operation. Understanding this helps when operating auroral propagation.
考试技巧
Best mode for auroral propagation = CW. Think 'A'uroral 'P'ropagation = 'C'W best. CW works best with auroral propagation because it's narrow bandwidth and less affected by auroral distortion. Not SSB, not FM, not RTTY - just CW.
记忆口诀
Best mode for auroral propagation = CW. Think 'A'uroral 'P'ropagation = 'C'W. CW works best with auroral propagation because it's narrow bandwidth and less affected by auroral distortion. Important for auroral operation.
实际应用示例
Auroral propagation: CW (Continuous Wave/Morse code) is the best emission mode. Auroral propagation causes signal distortion and Doppler shift, which affects voice modes (SSB, FM) more than CW. CW's narrow bandwidth and simple signal structure make it more tolerant of auroral distortion. This is the mode - CW is best for auroral propagation.
错误选项分析
Option B (SSB): Incorrect. SSB doesn't work as well as CW - CW is best for auroral propagation. SSB isn't the best. Option C (FM): Incorrect. FM doesn't work well with auroral propagation - CW is best. FM isn't the best. Option D (RTTY): Incorrect. RTTY doesn't work as well as CW - CW is best for auroral propagation. RTTY isn't the best.
知识点
Auroral propagation, Emission modes, CW, Best mode
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.