Basic Qualification · B-006 Feedlines and antenna systems · B-006-006-001
Which of the following antenna system conditions will cause a modern solid-state HF transceiver to automatically reduce power?
- A Excessive impedance mismatch between transceiver and transmission line
- B Transmitting to a balanced antenna with an unbalanced transmission line
- C Open circuit in lightning surge protector ground connection
- D Excessive antenna element movement in high winds
Correct answer: A — Excessive impedance mismatch between transceiver and transmission line. From the official ISED question bank, verified word for word.
Why
Modern solid-state transceivers protect their final amplifiers by sensing reflected power, which rises sharply when there is an excessive impedance mismatch between the transceiver and transmission line. The full explanation — and one for every question — is in Pro.
Practise this section
Getting the signal out: antennas, feedlines, SWR, baluns, matching, and why antenna length depends on frequency.