had new alternater but still get a whine when revving the engine

Yes the noise did not come back for about two months after the first alternater change, my repair shop puts refurbished alternaters as replacements to save me the cost of a new one,when I ask if this could be the reason he said they use them all the time and they are guaranteed. He is checking this Tuesday! he is a good mechanic so I trust him. Jim

Good luck , hope you get a good one next time.