Advanced Qualification · A-006 Receivers · A-006-002-009
What receiver stage combines a 14.25-MHz input signal with a 13.795-MHz oscillator signal to produce a 455-kHz intermediate frequency (IF) signal?
- A Multiplier
- B Mixer
- C BFO
- D VFO
Correct answer: B — Mixer. From the official ISED question bank, verified word for word.
Why
A mixer is the stage that takes two different radio frequencies and combines them to create a new frequency, which in this case is the difference between 14.25 MHz and 13.795 MHz, resulting in the 455-kilohertz intermediate frequency. The full explanation — and one for every question — is in Pro.
Practise this section
Receivers: superheterodyne design, selectivity, sensitivity, images, AGC and noise.