Basic Qualification · B-003 Station assembly, practice and safety · B-003-005-005
In an SSB/CW receiver, what is the purpose of the intermediate frequency (IF) filter?
- ASuppress spurious signals from the IF amplifier
- BReject RF from the product detector, passing only audio
- CProvide most of the selectivity of the receiver
- DFor SSB reception, select the desired sideband
Correct answer: C — Provide most of the selectivity of the receiver. From the official ISED question bank, verified word for word.
Why
The intermediate frequency filter shapes the signal path to block unwanted stations close in frequency, which is exactly what selectivity means. 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