Extra exam question E9H05
Subelement E9, ANTENNAS AND TRANSMISSION LINES· Group E9H
What challenge is presented by a small wire-loop antenna for direction finding?
- A.It has a bidirectional null pattern (correct answer)
- B.It does not have a clearly defined null
- C.It is practical for use only on VHF and higher bands
- D.All these choices are correct
WhyA small wire-loop antenna's fundamental challenge for direction finding is that it has a bidirectional null pattern. A small wire-loop DF antenna's fundamental challenge is that it has a bidirectional null pattern, two opposite nulls rather than one, so a bearing taken from the null alone is ambiguous about which of the two possible directions the signal is actually coming from, answer A. It does have a clearly defined null (that's actually its strength for DF work), and small loops work fine well below VHF, they aren't restricted to VHF and higher, so neither B, C, nor "all these choices" fits.
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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