My wife just bought me a Masterbuilt vertical gas smoker from Sears. They assembled it and I am not sure I got all the pamphlets that came with it. Chart in the back of the pamphlet lists amount of time, temperatures, and amount of wood chips needed to cook a given item. One of the things on the chart says how much charcoal to add. Example...for a 12 lb turkey it says 3 cups of wood chips and 8-10 lbs of charcoal. I am a rookie at this so I am not understanding why I would use charcoal in the chip pan if it is a gas smoker. I am cooking a turkey right now using only wood chips (hickory and apple) but they smoke out in about 10-15 minutes. If I have smoke rooling the entire time this thing is cooking, I am going to need three bags of chips not three cups. Should it smoke the entire time or just for a while and should I be packing some charcoal on the pan as well next time?