Basic Qualification · B-006 Feedlines and antenna systems · B-006-005-004
Which of the following can cause a high SWR reading?
- AGrounding the shield of the coaxial cable at the building entrance
- BUsing a very long transmission line
- CReplacing RG-213 coaxial cable with RG-58
- DAn open or short circuit in the antenna system
Correct answer: D — An open or short circuit in the antenna system. From the official ISED question bank, verified word for word.
Why
An open or short circuit in the antenna system breaks the path for radio energy, forcing it to bounce back toward the transmitter instead of radiating out. 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