Basic Qualification · B-003 Station assembly, practice and safety · B-003-019-005
You need to work on a power supply that has been taken offline. What is the first thing you should do once the cabinet is open?
- ADischarge the filter capacitors
- BBond the chassis to ground
- CPlace the unit on an insulating mat
- DShort the AC input leads together
Correct answer: A — Discharge the filter capacitors. From the official ISED question bank, verified word for word.
Why
Filter capacitors store dangerous electrical energy even after the power is turned off, acting like hidden batteries that can shock you instantly. The full explanation — and one for every question — is in Pro.
Practise this section
Station assembly, practice and safety is section B-003 of the Basic exam: Building a station safely: power supplies, grounding, RF exposure, lightning, feedline routing, and what a transmitter, receiver and transceiver actually do.
Drill B-003 — free, no account