How can conducted noise from an automobile battery charging system be suppressed?
By installing filter capacitors in series with the alternator leads
By installing a noise suppression resistor and a blocking capacitor at the battery
By installing a high-pass filter in series with the radio’s power lead and a low-pass filter in parallel with the antenna feed line
By installing ferrite chokes on the charging system leads✓Bonne réponse
Explication
Charging-system noise travels along the wiring as an in-phase RF component on multiple conductors, and ferrite chokes over those leads present a high impedance to it at radio frequencies while leaving the DC charging current untouched. Filter capacitors placed in series with the alternator leads would block the charging current itself.