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SESK: Stuff Everyone Should Know · sesk.info/hamg-corona-ball

What is the purpose of a corona ball on an HF mobile antenna?

To reduce RF voltage discharge from the antenna tip.

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  1. To increase the Q of the antenna
  2. To reduce damage if the antenna hits an object
  3. To reduce RF voltage discharge from the tip of the antenna ✔

Why: The tip of a whip carries high RF voltage that can arc into the air. A rounded corona ball spreads out the electric field and reduces that discharge.

Huh, didn't know that: A capacitance hat electrically lengthens a physically short mobile antenna.

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References

Answer: To reduce RF voltage discharge from the tip of the antenna. The tip of a whip carries high RF voltage that can arc into the air. A rounded corona ball spreads out the electric field and reduces that discharge.

  1. NCVEC 2023-2027 General Class Pool and Syllabus (6th Errata, Feb 4 2026) ncvec.org/downloads/General%20Class%20Pool%20and%20Syllabus%202023-2027%20Public%20Release%20with%206th%20Errata%20Feb%204%202026.pdf
    To reduce RF voltage discharge from the tip of the antenna while transmitting
    Checked 2026-10-10.

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