Advanced Qualification · A-006 Receivers · A-006-002-003
The first mixer in the receiver mixes the incoming signal with the local oscillator to produce:
- A a radio frequency
- B a high frequency oscillator (HFO) frequency
- C an intermediate frequency
- D an audio frequency
Correct answer: C — an intermediate frequency. From the official ISED question bank, verified word for word.
Why
The first mixer combines the incoming radio signal with a local oscillator to create a new, fixed frequency called an intermediate frequency, which is easier for the receiver to amplify and filter clearly. The full explanation — and one for every question — is in Pro.
Practise this section
Receivers: superheterodyne design, selectivity, sensitivity, images, AGC and noise.