Advanced Qualification · A-006 Receivers · A-006-001-009
A single conversion receiver with a 9 MHz IF has a local oscillator operating at 16 MHz. The frequency it is tuned to is:
- A 9 MHz
- B 7 MHz
- C 16 MHz
- D 21 MHz
Correct answer: B — 7 MHz. From the official ISED question bank, verified word for word.
Why
The receiver tunes to 7 MHz because the local oscillator mixes with the incoming signal to create the intermediate frequency, meaning the difference between the 16 MHz oscillator and the 9 MHz intermediate frequency equals the tuned signal. The full explanation — and one for every question — is in Pro.
Practise this section
Receivers: superheterodyne design, selectivity, sensitivity, images, AGC and noise.