General exam question G9A03
Subelement G9, ANTENNAS AND FEED LINES· Group G9A
G9A03
What is the nominal characteristic impedance of “window line” transmission line?
- A.50 ohms
- B.75 ohms
- C.100 ohms
- D.450 ohms (correct answer)
WhyWindow line transmission line has a nominal characteristic impedance of 450 ohms. "Window line," a ladder-line style open-wire feed line with molded windows between conductors, has a nominal characteristic impedance around 450 ohms, answer D. 50, 75, and 100 ohms are typical coaxial or twisted-pair impedances, not the figure associated with window line's wide conductor spacing.
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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