Basic Qualification · B-007 Radio wave propagation · B-007-007-010
En excluant les modes enrichis de propagation, quelle est la distance approximative moyenne de la propagation troposphérique d'un signal VHF?
- A1 600 km
- B800 km
- C2 400 km
- D3 200 km
Correct answer: B — 800 km. Question tirée de la banque officielle d'ISDE.
Why
Normal VHF signals travel in straight lines and are limited by the curve of the Earth, typically reaching about 800 km when atmospheric conditions are average. The full explanation — and one for every question — is in Pro.
Practise this section
Radio wave propagation is section B-007 of the Basic exam: How signals travel: the ionosphere and its layers, skip, ground wave, sporadic E, and which bands work when.
Drill B-007 — free, no account