FCC Question Pool Review

Technician Class (Element 2) • 2022-2026

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Question T0A07

From subelement T0 - T0A

T0A07
Answer: D

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

AAt the output connector of a transceiver
BAt the antenna feed point
CAt the ac power service panel
DOn a grounded panel near where feed lines enter the building

Why is this correct?

Lightning arresters must be installed on a grounded panel near where feed lines enter the building to intercept lightning energy before it reaches your equipment inside. Installing at the transceiver (A) or antenna feed point (B) provides no protection for the feed line itself. The AC service panel (C) is unrelated to coaxial feed line protection. The arrester's job is to shunt lightning current to ground before it can travel down the coax into your shack.

Memory tip

Think location, location, location: lightning protection works best at the boundary between outside and inside. The entry point is your last chance to divert energy to ground before it reaches expensive equipment indoors.

Learn more

Lightning arresters follow the 'border guard' principle in RF safety systems. Just as border guards inspect travelers before they enter a country, lightning arresters inspect RF energy at the building entry point. They're connected to the station's single-point ground system, which bonds all equipment grounds together per Part 97.403 requirements. This creates a controlled impedance path that diverts transient energy while allowing normal RF signals to pass through to your transceiver.

Think about it

Why do you think placing a lightning arrester at the antenna feed point wouldn't protect the long coaxial cable run back to your station?