Technician exam question T9B02
Subelement T9, ANTENNAS AND FEED LINES· Group T9B
What is the most common impedance of coaxial cables used in amateur radio?
- A.8 ohms
- B.50 ohms (correct answer)
- C.600 ohms
- D.12 ohms
Why50 ohms is the most common impedance of coaxial cables used in amateur radio. 50 ohms is the standard characteristic impedance of coaxial cable used throughout amateur radio, chosen as a practical compromise between power handling and loss, and matched to the impedance most amateur equipment and antennas are designed around, answer B. 8 ohms and 12 ohms (A, D) aren't standard coax impedances at all, and 600 ohms (C) is closer to the impedance of open-wire ladder line, not coax.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2026-2030 NCVEC Element 2 pool (public domain); the explanation above is original writing, see our methodology.
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