Which of the following applies when the FCC rules designate the amateur service as a secondary user on a band?
The correct answer is C: Amateur stations must not cause harmful interference to primary users and must accept interference from primary users. When FCC rules designate the amateur service as a secondary user on a band, amateurs must not cause harmful interference to primary users and must accept interference from primary users. Secondary status means amateurs can use the band but must yield to primary users. For amateur radio operators, understanding secondary status helps explain why you might experience interference and why you must be careful not to interfere with primary services.
Exam Tip
Secondary user = no interference to primary, accept interference from primary. Think 'S'econdary = 'S'ubordinate - must yield to primary users. Can operate anytime but must not interfere and must accept interference. Not about recording call signs or time restrictions.
Memory Aid
"Secondary user = no interference to primary, accept interference. Think 'S'econdary = 'S'ubordinate. Must not cause harmful interference to primary users and must accept interference from them. Can operate anytime but must yield."
Real-World Application
You operate on a band where amateurs are secondary users. A primary service (like a government station) starts operating on your frequency. You must yield - either QSY (change frequency) or accept the interference. You cannot cause harmful interference to them, and you must accept any interference they cause to you. This is the nature of secondary status.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Amateurs don't need to record primary service call signs - that's not a requirement. The requirement is to avoid interference and accept it.
Option B: Incorrect. Amateurs can use secondary bands at any time, not just during emergencies. The restriction is about interference, not timing.
Option D: Incorrect. Amateurs aren't restricted to specific hours - they can operate 24/7, but must yield to primary users when they're active.
题目解析
The correct answer is C: Amateur stations must not cause harmful interference to primary users and must accept interference from primary users. When FCC rules designate the amateur service as a secondary user on a band, amateurs must not cause harmful interference to primary users and must accept interference from primary users. Secondary status means amateurs can use the band but must yield to primary users. For amateur radio operators, understanding secondary status helps explain why you might experience interference and why you must be careful not to interfere with primary services.
考试技巧
Secondary user = no interference to primary, accept interference from primary. Think 'S'econdary = 'S'ubordinate - must yield to primary users. Can operate anytime but must not interfere and must accept interference. Not about recording call signs or time restrictions.
记忆口诀
Secondary user = no interference to primary, accept interference. Think 'S'econdary = 'S'ubordinate. Must not cause harmful interference to primary users and must accept interference from them. Can operate anytime but must yield.
实际应用示例
You operate on a band where amateurs are secondary users. A primary service (like a government station) starts operating on your frequency. You must yield - either QSY (change frequency) or accept the interference. You cannot cause harmful interference to them, and you must accept any interference they cause to you. This is the nature of secondary status.
错误选项分析
Option A: Incorrect. Amateurs don't need to record primary service call signs - that's not a requirement. The requirement is to avoid interference and accept it. Option B: Incorrect. Amateurs can use secondary bands at any time, not just during emergencies. The restriction is about interference, not timing. Option D: Incorrect. Amateurs aren't restricted to specific hours - they can operate 24/7, but must yield to primary users when they're active.
知识点
Secondary user status, Harmful interference, Band sharing, FCC regulations
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.