Basic Qualification · B-007 Radio wave propagation · B-007-006-007
At what point in the solar cycle does the 20-metre band usually support worldwide propagation during daylight hours?
- A Only at the minimum point of the solar cycle
- B Only at the maximum point of the solar cycle
- C At the beginning of the solar cycle
- D At any point in the solar cycle
Correct answer: D — At any point in the solar cycle. From the official ISED question bank, verified word for word.
Why
The 20-metre band is unique because it supports worldwide daytime communication regardless of where the Sun is in its eleven-year activity cycle. The full explanation — and one for every question — is in Pro.
Practise this section
How signals travel: the ionosphere and its layers, skip, ground wave, sporadic E, and which bands work when.