What is a possible cause of high voltages that produce RF burns?
The correct answer is D: The ground wire has high impedance on that frequency. A possible cause of high voltages that produce RF burns is that the ground wire has high impedance on that frequency. High-impedance ground wires can't effectively carry RF to ground, causing RF voltage to build up on equipment. For amateur radio operators, this is a safety concern. Understanding this helps prevent RF burns.
Exam Tip
RF burns cause = ground wire has high impedance. Think 'H'igh 'I'mpedance = 'H'igh 'I'mpedance prevents grounding. High-impedance ground wires can't effectively carry RF to ground, causing RF voltage buildup. Not wire shape, not insulation, not resonance - just high impedance.
Memory Aid
"RF burns cause = ground wire has high impedance. Think 'H'igh 'I'mpedance = 'H'igh 'I'mpedance prevents grounding. High-impedance ground wires can't effectively carry RF to ground, causing RF voltage buildup and burns."
Real-World Application
Your ground wire is too long or has poor connections, creating high impedance at RF frequencies. RF can't flow effectively to ground, causing voltage to build up on equipment enclosures. When you touch the equipment, you get an RF burn. Proper low-impedance grounding prevents this.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Flat braid vs round wire isn't the issue - both can work if properly installed. The issue is impedance, not wire shape.
Option B: Incorrect. Insulated wire for ground would prevent grounding - that's a problem, but high impedance is the specific cause of RF voltage buildup.
Option C: Incorrect. Ground rods aren't 'resonant' in a way that causes problems - resonance isn't the issue. High impedance is the issue.
题目解析
The correct answer is D: The ground wire has high impedance on that frequency. A possible cause of high voltages that produce RF burns is that the ground wire has high impedance on that frequency. High-impedance ground wires can't effectively carry RF to ground, causing RF voltage to build up on equipment. For amateur radio operators, this is a safety concern. Understanding this helps prevent RF burns.
考试技巧
RF burns cause = ground wire has high impedance. Think 'H'igh 'I'mpedance = 'H'igh 'I'mpedance prevents grounding. High-impedance ground wires can't effectively carry RF to ground, causing RF voltage buildup. Not wire shape, not insulation, not resonance - just high impedance.
记忆口诀
RF burns cause = ground wire has high impedance. Think 'H'igh 'I'mpedance = 'H'igh 'I'mpedance prevents grounding. High-impedance ground wires can't effectively carry RF to ground, causing RF voltage buildup and burns.
实际应用示例
Your ground wire is too long or has poor connections, creating high impedance at RF frequencies. RF can't flow effectively to ground, causing voltage to build up on equipment enclosures. When you touch the equipment, you get an RF burn. Proper low-impedance grounding prevents this.
错误选项分析
Option A: Incorrect. Flat braid vs round wire isn't the issue - both can work if properly installed. The issue is impedance, not wire shape. Option B: Incorrect. Insulated wire for ground would prevent grounding - that's a problem, but high impedance is the specific cause of RF voltage buildup. Option C: Incorrect. Ground rods aren't 'resonant' in a way that causes problems - resonance isn't the issue. High impedance is the issue.
知识点
RF burns, High voltages, Ground wire impedance, RF safety
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.