Basic Qualification · B-006 Feedlines and antenna systems · B-006-002-003
What kind of transmission line is made of two conductors held apart by insulated rods?
- AOpen-wire line
- BCoaxial cable
- CWindow line
- DTwisted pair
Correct answer: A — Open-wire line. From the official ISED question bank, verified word for word.
Why
Open-wire line fits the description because it uses two parallel wires kept apart by insulating rods or spacers, allowing the signal to travel between them without a surrounding shield. The full explanation — and one for every question — is in Pro.
Practise this section
Feedlines and antenna systems is section B-006 of the Basic exam: Getting the signal out: antennas, feedlines, SWR, baluns, matching, and why antenna length depends on frequency.
Drill B-006 — free, no account