Advanced Qualification · A-007 Feedlines and matching · A-007-006-007
Si le gain total de l'installation d'un radioamateur augmente de 3 dB, la puissance apparente rayonnée :
- Ademeure la même
- Bdiminue de moitié
- Cest doublée
- Ddiminue de 3 watts
Correct answer: C — est doublée. Question tirée de la banque officielle d'ISDE.
Why
A 3 dB increase in gain means the signal power has doubled because the decibel scale is logarithmic, where every 3 dB step represents a multiplication of power by two. The full explanation — and one for every question — is in Pro.
Practise this section
Feedlines and matching is section A-007 of the Advanced exam: Feedlines and matching at the advanced level: transmission line theory, impedance transformation, stubs and matching networks.
Drill A-007 — free, no account