I have a Materbuilt 40" propane smoker, and I am having an issue with getting it to give me a tbs. I soak the chips for atleast half an hour or more. I have read about using a cast iron skillet which I have been and still no help. I am burning with the burner dial as low as it will go but I have yellow tipped flame closest to the chip tray. What am I doing wrong? Was there an installation error? Have I missed a mod from one of the other topics? Seems like within hald hour or hour my chips are burned up and smoked out. I run with the top back vent wide open. Any help would be appreciated.