Ham Radio Guide
Search

Learn / Technician course

Lesson 10: Safety

Lesson 10 of 10, syllabus topic T0. The exam asks 3 questions from this topic, one from each of its 3 groups.

Safety comes last because it draws on everything before it: electrical hazards, antenna work and RF exposure.

What you will learn

  • T0A Power circuits and hazards: hazardous voltages, fuses and circuit breakers, grounding, electrical code compliance; Lightning protection; Battery safety
  • T0B Antenna safety: tower safety and grounding, installing antennas, antenna supports
  • T0C RF hazards: radiation exposure, proximity to antennas, recognized safe power levels, radiation types, duty cycle

1. Read

  1. Electrical and antenna safety: How electric shock harms youHelps with T0A
  2. Electrical and antenna safety: Fuses, breakers and GFCIsHelps with T0A
  3. Electrical and antenna safety: Grounding and bondingHelps with T0A
  4. Electrical and antenna safety: LightningHelps with T0A
  5. Electrical and antenna safety: BatteriesHelps with T0A
  6. Electrical and antenna safety: Towers, masts and power linesHelps with T0B
  7. RF exposure and your station: What RF does to the bodyHelps with T0C
  8. RF exposure and your station: Maximum permissible exposureHelps with T0C
  9. RF exposure and your station: What changes your exposureHelps with T0C
  10. RF exposure and your station: How to evaluate your stationHelps with T0C
  11. RF exposure and your station: Practical stepsHelps with T0C
  12. Putting up antennas: Plan around power lines firstHelps with T0B
  13. Putting up antennas: Masts, tripods and roof mountsHelps with T0B
  14. Putting up antennas: Lightning protection where the coax comes inHelps with T0A, T0B
  15. All 36 T0 questions with their answers and explanationsEvery group, with the rule or source behind each answer

2. Explore

  • RF exposure evaluator

    Double the distance to the antenna and watch the power density fall to one quarter: in the far field it falls with the square of the distance.

  • RF exposure evaluator

    Cut the duty cycle from 100 to 50 percent. The average power density halves, which is why the allowable power density doubles.

    This is exam question T0C03.

3. Practice

Practice one group at a time. A group is ready when you have answered every one of its questions and learned at least 80 percent of them; a question counts as learned when your last three answers to it were correct. To review quickly, go through this lesson’s questions as flashcards.

Loading practice questions…