Basic Qualification · B-006 Feedlines and antenna systems · B-006-011-011
If the forward gain of a six-element Yagi is about 10 dBi, what would the gain of two of these antennas be if they were "stacked"?
- A 13 dBi
- B 7 dBi
- C 20 dBi
- D 10 dBi
Correct answer: A — 13 dBi. From the official ISED question bank, verified word for word.
Why
Stacking two identical antennas doubles the effective power in the desired direction, which adds exactly 3 decibels to the gain. 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.