Advanced Qualification · A-006 Receivers · A-006-001-006
In a dual-conversion superheterodyne receiver what are the respective aims of the first and second conversion:
- A selectivity and dynamic range
- B image rejection and noise figure
- C image rejection and selectivity
- D selectivity and image rejection
Correct answer: C — image rejection and selectivity. From the official ISED question bank, verified word for word.
Why
The first conversion uses a high intermediate frequency to push unwanted mirror signals far away, achieving image rejection, while the second conversion drops the signal to a low frequency where sharp filters can easily isolate the desired station, providing selectivity. The full explanation — and one for every question — is in Pro.
Practise this section
Receivers: superheterodyne design, selectivity, sensitivity, images, AGC and noise.