Basic Qualification · B-006 Feedlines and antenna systems · B-006-002-003
Quel type de ligne de transmission est faite de deux conducteurs, tenus séparés par des tiges isolantes?
- AUne ligne ouverte, dite "en échelle"
- BUn câble coaxial
- CUne ligne bifilaire ajourée ("window line")
- DUne paire torsadée
Correct answer: A — Une ligne ouverte, dite "en échelle". Question tirée de la banque officielle d'ISDE.
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