Technician exam question T9B11
Subelement T9, ANTENNAS AND FEED LINES· Group T9B
T9B11
Which of the following types of feed line has the lowest loss?
- A.50-ohm flexible coax
- B.Multi-conductor unbalanced cable
- C.Air-insulated hardline (correct answer)
- D.75-ohm flexible coax
WhyAir-insulated hardline is the type of feed line with the lowest loss. Air-insulated hardline uses air, rather than a lossy solid plastic, as its dielectric, which gives it the lowest loss of the common feed line types listed, answer C. Flexible 50-ohm and 75-ohm coax (A, D) both use solid dielectrics with more loss than hardline's air-spaced design, and multi-conductor unbalanced cable (B) isn't a low-loss RF feed line design at all.
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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