Extra exam question E9D06
Subelement E9, ANTENNAS AND TRANSMISSION LINES· Group E9D
What happens to SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?
- A.It is increased
- B.It is decreased (correct answer)
- C.It is unchanged if the loading coil is located at the feed point
- D.It is unchanged if the loading coil is located at a voltage maximum point
WhyUsing one or more loading coils to resonate an electrically short antenna decreases its SWR bandwidth. Using one or more loading coils to resonate an electrically short antenna decreases its SWR bandwidth, since the added coil raises the antenna's effective Q, and a higher Q always narrows the range of frequencies over which the antenna stays reasonably well matched, answer B. SWR bandwidth doesn't increase from loading, and it isn't unchanged regardless of where the coil sits, coil placement (and how much loading is used) directly affects the resulting bandwidth.
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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