8.1 Towers and Lightning

Mon, 01 Jan 0001 00:00:00 +0000

Section 8.1: Towers and Lightning #

A taller antenna is hard to resist when you’re chasing weak signals. Someone still has to put it up, and climb back up the day a connector lets in water. Before anyone climbs, the usual rules apply: never climb alone, check the harness rating and service life, lock out and tag circuits feeding the tower, and keep its antennas off the air. None of that replaces climbing training, suitable fall-protection equipment, and a rescue plan.

8.2 Evaluating RF Exposure

Mon, 01 Jan 0001 00:00:00 +0000

Section 8.2: Evaluating RF Exposure #

Strong RF fields heat body tissue, and the FCC’s exposure limits keep that heating well below harmful levels. The heating happens inside the body, though, where no station meter can reach.

Energy Absorbed by the Body #

The core limits cap the RF power each kilogram of tissue absorbs. Maximum permissible exposure (MPE) limits translate them into field strengths or power densities you can check where people may be. The MPE limits are tightest where the whole body absorbs most efficiently: at wavelengths of a few meters, where a person’s height suits the body as a receiving antenna.

8. Safety on The HamStudy Amateur Extra Class HamBook (2024 - 2028)

8.1 Towers and Lightning

Section 8.1: Towers and Lightning #

8.2 Evaluating RF Exposure

Section 8.2: Evaluating RF Exposure #

Energy Absorbed by the Body #