Basic Qualification · B-007 Radio wave propagation · B-007-007-006
Sur quelle bande du service de radioamateur la propagation par ionisation sporadique de la couche E permet-elle le plus souvent de grandes distances?
- A160 mètres
- B20 mètres
- C2 mètres
- D6 mètres
Correct answer: D — 6 mètres. Question tirée de la banque officielle d'ISDE.
Why
Sporadic-E occurs when dense patches of ionisation form in the lower atmosphere, acting like a mirror that bounces radio signals much farther than usual. 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