Technician exam: safety
Electrical safety, RF exposure limits, tower and antenna safety, and batteries. 36 questions, 10 at a time, starting with ones you haven't seen.
Rules to remember10 key safety rulesShow the rules
- In US 120 V wiring, black is the hot wire, white is neutral, and green or bare is the equipment ground. (p. 72)
- A 20-amp fuse lets far more current flow than the circuit was designed for before it blows, so wiring can overheat and start a fire. (p. 72)
- Three-wire cords, a common safety ground, and discharging high-voltage capacitors before working inside equipment all protect against shock. (p. 72)
- Never climb a tower alone; a helper or observer must be there to assist or call for help in an emergency. (p. 74)
- Place the antenna far enough away that even if it falls, no part can come within 10 feet of the power lines. (p. 74)
- Never climb a crank-up tower unless it is fully retracted or locked with mechanical safety devices, because the sections can slide down. (p. 74)
- A tower should have separate eight-foot ground rods at each leg, bonded to the tower and to each other. (p. 75)
- You can evaluate exposure by OET Bulletin 65 calculations, by computer modeling, or by measuring field strength with calibrated equipment. (p. 76)
- Moving antennas farther from where people are is an effective way to reduce RF exposure. (p. 77)
- Duty cycle is the percentage of the averaging time that the transmitter is actually transmitting. (p. 77)
Taken from the explanations to checked practice questions; page numbers link to the official handbook.
Sample safety questions
1.Which of the following establishes grounding requirements for an amateur radio tower or antenna?
- ALocal electrical codes
- BFAA tower lighting regulations
- CFCC Part 97 rules
- DUL recommended practices
Show the answer
✓ A. Local electrical codes
Grounding requirements for towers and antennas come from local electrical codes, not from FCC amateur rules.
2.Which of the following is an important safety rule to remember when using a crank-up tower?
- AThis type of tower must not be climbed unless it is retracted, or mechanical safety locking devices have been installed
- BThis type of tower must never be grounded
- CThis type of tower must never be painted
- DAll these choices are correct
Show the answer
✓ A. This type of tower must not be climbed unless it is retracted, or mechanical safety locking devices have been installed
Never climb a crank-up tower unless it is fully retracted or locked with mechanical safety devices, because the sections can slide down.
3.Which of the following precautions should be taken when measuring high voltages with a voltmeter?
- AEnsure that the voltmeter has very low impedance
- BEnsure that the voltmeter is set to the correct frequency
- CEnsure that the circuit is grounded through the voltmeter
- DEnsure that the voltmeter and its leads are rated for use at the voltages being measured
Show the answer
✓ D. Ensure that the voltmeter and its leads are rated for use at the voltages being measured
Use a meter and test leads rated for the voltage you are measuring, because underrated equipment can fail and expose you to that voltage.
4.What should be done to all external ground rods or earth connections?
- AWaterproof them with silicone caulk or electrical tape
- BTune them for resonance on the lowest frequency of operation
- CKeep them as far apart as possible
- DBond them together with heavy wire or conductive strap
Show the answer
✓ D. Bond them together with heavy wire or conductive strap
All ground rods and earth connections should be bonded together with heavy wire or strap so they stay at the same potential during a lightning strike.