Basic Qualification · B-006 Feedlines and antenna systems · B-006-010-010
Why is a loading coil often used with an HF mobile vertical antenna?
- A To lower the Q
- B To filter out electrical noise
- C To tune out capacitive reactance
- D To lower the losses
Correct answer: C — To tune out capacitive reactance. From the official ISED question bank, verified word for word.
Why
A short mobile vertical antenna acts like a capacitor because it is too small to be a full wave, creating capacitive reactance that blocks efficient power transfer. 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.