Deep Dive: G4C05
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.
Why Other Answers 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.
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 Example
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.
Source & Coverage
Question Pool: 2023-2027 Question Pool
Subelement: G4C
Reference: 2023-2027 Question Pool · G4 - Amateur Radio Practices
Key Concepts
Verified Content
Question from the official FCC General Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the G4C topic.