Safety
RF and electrical safety
The General exam tests RF exposure, high-voltage safety, grounding, and tower safety. Know that RF exposure limits depend on frequency and power density, and that the safe distance increases with power and antenna gain. Know that you must not touch an antenna while transmitting and that you should never work on an antenna near power lines.
Grounding and lightning
Know that a station ground should be bonded to the building's electrical ground and that a lightning arrestor should be installed on the feed line. Know that a ground rod should be driven at least 8 feet deep and bonded to the electrical service ground. Never rely on a single ground rod for lightning protection; use a low-impedance path and bond everything together.
Towers and batteries
Know that tower work requires fall protection, that antennas must be clear of power lines, and that batteries can release hydrogen gas and must be ventilated. Know that lead-acid batteries can deliver enormous current and should be fused. Know that a dummy load gets hot and should not be touched after use.
Worked example
If a question asks how to protect a station from lightning, the best answer is: bond the station ground to the electrical service ground, install a lightning arrestor on the feed line, and disconnect antennas when not in use. A single ground rod alone is not sufficient.
Common traps
Assuming a ground rod alone protects against lightning. Forgetting that RF exposure distance grows with antenna gain. Touching a dummy load or antenna immediately after transmitting.