Basic Qualification · B-006 Feedlines and antenna systems · B-006-005-005
What is the main adverse effect due to operating with high SWR?
- AIncreased transmission line radiation
- BIncreased common-mode current
- CIncreased transmission line loss
- DIncreased receive noise level
Correct answer: C — Increased transmission line loss. From the official ISED question bank, verified word for word.
Why
When the standing wave ratio, or SWR, is high, much of the radio energy bounces back and forth along the feedline instead of reaching the antenna. 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