ARRL Technician Practice Exam

What is the maximum power level that an amateur radio station can use at VHF frequencies before an RF exposure evaluation is required?

1. 25 watts PEP at the antenna

2. 50 watts PEP at the antenna

3. 100 watts PEP at the antenna

4. 150 watts PEP at the antenna

The correct answer is: 50 watts PEP at the antenna

The maximum power level that triggers the need for an RF exposure evaluation at VHF frequencies is set at 50 watts peak envelope power (PEP) at the antenna. This standard is grounded in concerns regarding potential health risks associated with exposure to radio frequency energy. When operating at or below this power threshold, the Federal Communications Commission (FCC) considers it sufficient that the amateur operator does not need to conduct a detailed evaluation of RF exposure. The rationale behind this limit is based on research and guidelines from agencies such as the Institute of Electrical and Electronics Engineers (IEEE) and the National Council on Radiation Protection and Measurements (NCRP), which outline exposure limits for both occupational and general public exposure. Power levels above 50 watts PEP necessitate an evaluation to ensure compliance with established safe exposure limits, reflecting a responsible approach to public health and safety in amateur radio operation.