Updated: Dec 9, 2025 | Source: 2022-2026 Question Pool | Topic: T0A
T0A07T0A

Where should a lightning arrester be installed in a coaxial feed line?

Deep Dive: T0A07

The correct answer is D: On a grounded panel near where feed lines enter the building. A lightning arrester should be installed on a grounded panel near where feed lines enter the building. This location provides protection by diverting lightning energy to ground before it can enter your station equipment. The arrester must be well-grounded and located at the entry point. For amateur radio operators, proper lightning protection is essential for equipment safety. Understanding arrester placement helps protect your investment from lightning damage.

Why Other Answers Are Wrong

Option A: Incorrect. Installing at the transceiver output doesn't protect the feed line or equipment - lightning can still enter through the feed line and damage equipment before reaching the transceiver. Option B: Incorrect. Installing at the antenna feed point doesn't protect equipment inside - the arrester needs to be at the building entry to protect interior equipment. Option C: Incorrect. Installing at the AC power panel doesn't protect RF feed lines - that's for power line protection, not antenna feed line protection.

Exam Tip

Lightning arrester = at building entry on grounded panel. Think 'L'ightning 'A'rrester = 'L'ocation 'A't entry. Protects equipment by diverting lightning to ground before it enters. Not at transceiver, antenna, or power panel.

Memory Aid

Lightning arrester = at building entry on grounded panel. Think 'L'ightning 'A'rrester = 'L'ocation 'A't entry. Protects equipment by diverting lightning to ground. Must be well-grounded.

Real-World Example

Your feed line enters your house through a wall. You install a lightning arrester on a grounded panel right at that entry point. If lightning strikes your antenna, the arrester diverts the energy to ground before it can travel down the feed line and damage your transceiver and other equipment inside. The arrester must be well-grounded to work properly.

Source & Coverage

Question Pool: 2022-2026 Question Pool

Subelement: T0A

Reference: 2022-2026 Question Pool · T0 - Safety

Key Concepts

Lightning arresters Lightning protection Feed line protection Station safety

Verified Content

Question from the official FCC Technician Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the T0A topic.