Basic Qualification · B-003 Station assembly, practice and safety · B-003-005-004
In an SSB/CW receiver, what is the purpose of the signal generated by the local oscillator?
- AIt is mixed with the incoming signal to produce the intermediate frequency
- BIt is mixed with the beat frequency oscillator signal to produce audio
- CIt is fed to the receiver input to provide band edge markers
- DIt is mixed with the intermediate frequency signal to produce a CW sidetone
Correct answer: A — It is mixed with the incoming signal to produce the intermediate frequency. From the official ISED question bank, verified word for word.
Why
The local oscillator creates a steady radio wave that the receiver mixes with the incoming signal from the antenna. 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