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Earth and protect antennas and the radio room from lightning

Outdoor antennas and their cables can bring lightning surges into the house. Bring every cable into one protected entry point bonded to the electrical earth.

How

1. Plan a single-point ground panel where every coax and control line enters the house, as ARRL guidance describes, and bond it to the building's main earthing system.
2. Fit an in-line coax lightning protector on every antenna feed at that panel, chosen to add little loss.
3. Use short, straight, wide copper strap for the connection to the external ground, as the ARRL article advises; a thin wire to a water pipe is not enough.
4. Keep unprotected incoming cables apart from protected cables inside, so surges cannot jump across.
5. Bond each radio's chassis to the panel. ARRL suggests Type 3 surge protectors at the panel should be at least 10 m from the service panel, or add a Type 2 or Type 1 protector closer to the supply.
6. The NWS warns that typical surge protectors will not stop a direct strike and that you should not unplug equipment during a storm. Disconnect antennas before storms arrive, not during them.
7. Coordinate with the power module's earthing plan (power-19).

Safety: Stay away from radios, antennas and their cables during thunderstorms.

Do these first

• power-19

Sources

1. Grounding and Bonding for the Amateur. ARRL, accessed 2026-11
2. Lightning Protection for the Amateur Radio Station, Part 2 (QST, July 2002). ARRL, accessed 2026-11
3. Lightning Safety Indoors. US National Weather Service, accessed 2026-11

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