General exam question G9D02
Subelement G9, ANTENNAS AND FEED LINES· Group G9D
What is the feed point impedance of an end-fed half-wave antenna?
- A.Very low
- B.Approximately 50 ohms
- C.Approximately 300 ohms
- D.Very high (correct answer)
WhyAn end-fed half-wave antenna has a very high feed point impedance. Feeding a half-wave antenna right at one of its ends, rather than at the low-impedance center, connects to a point of high voltage and low current, which corresponds to a very high feed point impedance, answer D. It isn't very low, isn't close to a coax-friendly 50 ohms, and isn't near the roughly 300-ohm impedance of some folded configurations, an end feed point on a plain half-wave wire is characteristically very high impedance, so A, B, and C are wrong.
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.
Related questions
- G9D01Which of the following antenna types will be most effective as a near vertical incidence skywave (NVIS) antenna for short-skip communications on 40 meters during the day?
- G9D03In which direction is the maximum radiation from a VHF/UHF “halo” antenna?
- G9D04What is the primary function of antenna traps?
- G9D05What is an advantage of vertically stacking horizontally polarized Yagi antennas?
- G9D06Which of the following is an advantage of a log-periodic antenna?