Lightning Protection

Now that Spring has finally arrived, us dwellars of the colder climates start to think about antenna maintenance and replacement. I know I’m looking at my own antenna system and making plans for improvement and maintenance. I also have some trees that will need pruning back so they won’t interfere with my wire antennas.

The other harbinger of Spring is lightning and severe weather. I’ve been asked quite a few questions over the last two weeks about lightning protection. Here are my guidelines for a safe antenna installation:

  1. Lightning will follow the path of least resistance. Your antenna system should be bonded to an earth ground via a heavy copper or copper clad steel line connected to an eight foot ground rod.
  2. Lightning will also follow down your feedline. A lightning arrestor inline on your coax will minimize lightning’s effects. The arrestor needs to be bonded to the same earth ground as your other ground line.
  3. If you are grounding a mast or tower with multiple antennas, all antennas need to share the same ground system. Multiple grounds will cause more harm than good if lightning hits.

The ARRL has an excellent collection of resources for lightning protection. Almost all grounding recommendations are based on the National Electric Code and can change as the code is updated. I recommend that you visit the ARRL’s site for the latest information on grounding and lightning protection: http://www.arrl.org/tis/info/lightning.html

Finally, I’m not a licensed electrition, my advice may be contrary to your local ordinances. Please seek out an expert when an expert is necessary.