When using a directional antenna, how might your station be able to communicate with a distant repeater if buildings or obstructions are blocking the direct line of sight path?
The correct answer is B: Try to find a path that reflects signals to the repeater. When buildings or obstructions block the direct line-of-sight path to a repeater, you can use a directional antenna to find a reflected path that bounces signals around the obstruction to reach the repeater.
Radio signals can reflect off buildings, terrain, or other objects. By pointing your directional antenna in different directions, you might find a reflection path that gets your signal to the repeater even though the direct path is blocked. This is a common technique in urban areas where buildings block direct paths. You experiment with different antenna directions to find a reflection that works.
Exam Tip
Blocked path = Find reflection. Remember: When obstructions block the direct path, use a directional antenna to find a reflection path that bounces signals around the obstruction to reach the repeater.
Memory Aid
"**B**locked **P**ath = **B**ounce **P**ath (think 'BP = BP' = Bounce Path, find reflection)"
Real-World Application
You're in a valley and a hill blocks your direct line-of-sight to a repeater on the other side. You use a directional Yagi antenna and experiment with different directions. You find that pointing the antenna toward a large building on a nearby ridge creates a reflection path - your signal bounces off the building and reaches the repeater, even though the direct path is blocked.
FCC Part 97.3Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Changing polarization might help slightly, but it won't solve a line-of-sight blockage. Finding a reflection path is more effective.
Option C: Incorrect. 'Long path' refers to signals traveling the long way around the Earth, not to finding alternative paths around local obstructions.
Option D: Incorrect. Increasing antenna SWR doesn't help with obstructions. High SWR indicates an antenna problem, not a solution to blocked paths.
题目解析
The correct answer is B: Try to find a path that reflects signals to the repeater. When buildings or obstructions block the direct line-of-sight path to a repeater, you can use a directional antenna to find a reflected path that bounces signals around the obstruction to reach the repeater. Radio signals can reflect off buildings, terrain, or other objects. By pointing your directional antenna in different directions, you might find a reflection path that gets your signal to the repeater even though the direct path is blocked. This is a common technique in urban areas where buildings block direct paths. You experiment with different antenna directions to find a reflection that works.
考试技巧
Blocked path = Find reflection. Remember: When obstructions block the direct path, use a directional antenna to find a reflection path that bounces signals around the obstruction to reach the repeater.
记忆口诀
**B**locked **P**ath = **B**ounce **P**ath (think 'BP = BP' = Bounce Path, find reflection)
实际应用示例
You're in a valley and a hill blocks your direct line-of-sight to a repeater on the other side. You use a directional Yagi antenna and experiment with different directions. You find that pointing the antenna toward a large building on a nearby ridge creates a reflection path - your signal bounces off the building and reaches the repeater, even though the direct path is blocked.
错误选项分析
Option A: Incorrect. Changing polarization might help slightly, but it won't solve a line-of-sight blockage. Finding a reflection path is more effective. Option C: Incorrect. 'Long path' refers to signals traveling the long way around the Earth, not to finding alternative paths around local obstructions. Option D: Incorrect. Increasing antenna SWR doesn't help with obstructions. High SWR indicates an antenna problem, not a solution to blocked paths.
知识点
Signal reflection, Directional antenna, Obstruction, Path finding
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.