General exam question G9C05
Subelement G9, ANTENNAS AND FEED LINES· Group G9C
What is the primary effect of increasing boom length and adding directors to a Yagi antenna?
- A.Gain increases (correct answer)
- B.Beamwidth increases
- C.Front-to-back ratio decreases
- D.Resonant frequency is lower
WhyThe primary effect of increasing boom length and adding directors to a Yagi antenna is that gain increases. Adding more directors and stretching the boom out longer increases the antenna's effective aperture and improves how the elements combine constructively in the forward direction, which is exactly what raises a Yagi's forward gain, answer A. A longer boom with more directors actually narrows the beamwidth rather than widening it, doesn't inherently worsen front-to-back ratio, and doesn't change the antenna's resonant frequency, so B, C, and D 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.
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