well, i have an error in my calculations of the frequency of the alternator whine - i estimated (did not have equipment to measure) the whine to be around 2-3 kHz, but i think it is much higher. The filter attenuates some of the whine on the lower end, when engine is just idling around 600-700 RPMs, but once the engine goes into road speeds, the whine is back... I am going to see if i can get the equipment at work to measure the spectrum of the whine, and then i will recalculate the filter - on the pictures i am missing 4700 mF capacitor, that is soldered into the filter... and I don't remember the number of winds - it is a 12 gauge speaker wire, about 20 feet long wrapped on the metal rod...