Deep Dive: G4E02
The correct answer is D: To reduce RF voltage discharge from the tip of the antenna while transmitting. The purpose of a corona ball on an HF mobile antenna is to reduce RF voltage discharge from the tip of the antenna while transmitting. Corona balls are smooth, rounded objects that reduce sharp points where high RF voltage can cause corona discharge. For amateur radio operators, this prevents RF losses and interference. Understanding this helps when using mobile antennas.
Why Other Answers Are Wrong
Option A: Incorrect. Corona balls don't narrow operating bandwidth - they don't affect bandwidth. Bandwidth narrowing isn't the purpose. Option B: Incorrect. Corona balls don't increase antenna Q - they don't affect Q significantly. Q increase isn't the purpose. Option C: Incorrect. Corona balls don't reduce damage from striking objects - that's about antenna strength, not corona balls. Physical protection isn't the purpose.
Exam Tip
Corona ball purpose = reduce RF voltage discharge from antenna tip. Think 'C'orona 'B'all = 'C'ontrols 'B'right discharge (corona). Smooth, rounded object reduces sharp points where high RF voltage causes corona discharge. Not bandwidth, not Q, not physical protection - just corona reduction.
Memory Aid
Corona ball purpose = reduce RF voltage discharge from antenna tip. Think 'C'orona 'B'all = 'C'ontrols 'B'right discharge. Smooth, rounded object reduces sharp points where high RF voltage causes corona discharge. Prevents RF losses and interference.
Real-World Example
You operate an HF mobile antenna with high RF voltage at the tip. Without a corona ball, sharp points can cause corona discharge (visible glow, RF losses, interference). You add a corona ball (smooth, rounded object) at the tip. This reduces sharp points, preventing corona discharge and improving efficiency.
Source & Coverage
Question Pool: 2023-2027 Question Pool
Subelement: G4E
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 G4E topic.