Basic Qualification · B-007 Radio wave propagation · B-007-001-001
Quel genre de propagation est utilisé entre deux émetteurs-récepteurs VHF situés relativement près l'un de l'autre?
- APropagation aurorale
- BPropagation en visibilité directe
- CPropagation troposphérique guidée (par conduit)
- DPropagation ionosphérique
Correct answer: B — Propagation en visibilité directe. Question tirée de la banque officielle d'ISDE.
Why
VHF signals travel in straight lines like light, so two nearby radios usually communicate only if they can see each other directly without hills or buildings blocking the path. 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