General exam question G4C10
Subelement G4, AMATEUR RADIO PRACTICES· Group G4C
What could be a symptom caused by a ground loop in your station’s audio connections?
- A.You receive reports of “hum” on your station’s transmitted signal (correct answer)
- B.The SWR reading for one or more antennas is suddenly very high
- C.An item of station equipment starts to draw excessive amounts of current
- D.You receive reports of harmonic interference from your station
WhyA ground loop in a station's audio connections can cause reports of hum on the station's transmitted signal. A ground loop creates small, uncontrolled currents in the station's audio wiring at the AC line frequency, and those currents typically show up as audible hum riding on the transmitted audio, which is what other stations report hearing, answer A. It doesn't cause a sudden SWR spike, excessive current draw by other equipment, or harmonic interference reports, those point to different problems.
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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