Extra exam question E4C13
Subelement E4, AMATEUR PRACTICES· Group E4C
What is reciprocal mixing?
- A.Two out-of-band signals mixing to generate an in-band spurious signal
- B.In-phase signals cancelling in a mixer resulting in loss of receiver sensitivity
- C.Two digital signals combining from alternate time slots
- D.Local oscillator phase noise mixing with adjacent strong signals to create interference to desired signals (correct answer)
WhyReciprocal mixing is local oscillator phase noise mixing with an adjacent strong signal to create interference to a desired signal. Reciprocal mixing happens when a local oscillator's own phase noise mixes with a strong signal on a nearby frequency, producing interference that lands right on top of a desired weaker signal even though that weaker signal itself did nothing wrong, answer D. It isn't two out-of-band signals producing an in-band spurious product, isn't in-phase cancellation in a mixer, and has nothing to do with combining digital signals from different time slots.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2024-2028 NCVEC Element 4 pool (public domain); the explanation above is original writing, see our methodology.
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