What is the minimum safe distance from a power line to allow when installing an antenna?
The correct answer is D: Enough so that if the antenna falls, no part of it can come closer than 10 feet to the power wires. The minimum safe distance from a power line when installing an antenna is enough distance so that if the antenna falls, no part of it can come closer than 10 feet to the power wires. This accounts for the antenna's length and ensures safe clearance even if it falls. For amateur radio operators, this is a critical safety rule. The 10-foot minimum is a safety standard that prevents contact with power lines.
Exam Tip
Antenna distance from power line = 10 feet minimum if antenna falls. Think '1'0 feet = '1'0 feet minimum clearance. Must account for antenna falling, not just heights. Safety standard to prevent contact.
Memory Aid
"Antenna distance = 10 feet minimum if falls. Think '1'0 feet = '1'0 feet minimum clearance. Must account for antenna falling completely. Critical safety rule to prevent power line contact."
Real-World Application
You're installing a 20-foot vertical antenna. Power lines are 30 feet high. You position the antenna so that even if it falls over completely, the tip will be at least 10 feet away from the power lines. This might require the antenna base to be 30+ feet from the power line to account for the antenna's length when fallen.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Adding heights and multiplying by 1.5 isn't the correct method - the distance must account for the antenna falling, not just heights.
Option B: Incorrect. Just the power line height isn't sufficient - you must account for the antenna falling and maintaining 10-foot clearance.
Option C: Incorrect. Half-wavelength distance isn't related to power line safety - that's an antenna spacing consideration, not a safety distance.
题目解析
The correct answer is D: Enough so that if the antenna falls, no part of it can come closer than 10 feet to the power wires. The minimum safe distance from a power line when installing an antenna is enough distance so that if the antenna falls, no part of it can come closer than 10 feet to the power wires. This accounts for the antenna's length and ensures safe clearance even if it falls. For amateur radio operators, this is a critical safety rule. The 10-foot minimum is a safety standard that prevents contact with power lines.
考试技巧
Antenna distance from power line = 10 feet minimum if antenna falls. Think '1'0 feet = '1'0 feet minimum clearance. Must account for antenna falling, not just heights. Safety standard to prevent contact.
记忆口诀
Antenna distance = 10 feet minimum if falls. Think '1'0 feet = '1'0 feet minimum clearance. Must account for antenna falling completely. Critical safety rule to prevent power line contact.
实际应用示例
You're installing a 20-foot vertical antenna. Power lines are 30 feet high. You position the antenna so that even if it falls over completely, the tip will be at least 10 feet away from the power lines. This might require the antenna base to be 30+ feet from the power line to account for the antenna's length when fallen.
错误选项分析
Option A: Incorrect. Adding heights and multiplying by 1.5 isn't the correct method - the distance must account for the antenna falling, not just heights. Option B: Incorrect. Just the power line height isn't sufficient - you must account for the antenna falling and maintaining 10-foot clearance. Option C: Incorrect. Half-wavelength distance isn't related to power line safety - that's an antenna spacing consideration, not a safety distance.
知识点
Antenna installation, Power line clearance, Safety distance, Electrical safety
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.