An apparatus and method are provided for minimizing noise on a power supply line (105) of a mobile radio, such as generated in a vehicular environment. An adaptive power supply conditioner (100) detects unwanted noise on the vehicle's power supply line (105) and via the use of an adaptive noise canceller (140), generates a cancellation signal (145) having the same amplitude but opposite phase of the input signal's detected noise. The cancellation signal (145) is fed forward and combined with the power supply line (105) in order to minimize unwanted noise on the supply line (105) leading to the mobile radio. The conditioner's output (165) is checked for further error and is fed back to the adaptive noise filter (140) for further filtering and the generation of an updated cancellation signal based on current noise conditions.