General exam question G8B01
Subelement G8, SIGNALS AND EMISSIONS· Group G8B
Which mixer input is varied or tuned to convert signals of different frequencies to an intermediate frequency (IF)?
- A.Image frequency
- B.Local oscillator (correct answer)
- C.RF input
- D.Beat frequency oscillator
WhyThe local oscillator is the mixer input varied or tuned to convert signals of different frequencies to an intermediate frequency. In a superheterodyne receiver, the local oscillator's frequency is the one that's varied or tuned, and mixing it against the incoming signal produces the fixed intermediate frequency the rest of the receiver is built around, answer B. The image frequency and RF input are the signals being received, not the tuning element, and a beat frequency oscillator is used later, for CW/SSB detection, not for the initial IF conversion.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2023-2027 NCVEC Element 3 pool (public domain); the explanation above is original writing, see our methodology.
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