A system and method for organizing and analyzing field warranty data including a warranty interface provided with warranty data from a warranty group. The powder process uses a unique combination of steps for packing, compacting and heat treating the powders. Also disclosed is a process for producing a metallic mirror, comprising the steps of forming the intermediate layer by vacuum deposition on a metallic polygonal mirror substrate metal, forming the metallic reflective layer of Cu by vacuum deposition on the intermediate layer, and forming the protective layer by vacuum deposition on the metallic reflective layer. The final blow tube is supported for vertical displacement between an up position where the open end of the final blow tube is proximate the top of a blown parison and a down position where the open end of the final blow tube is proximate the bottom of a blown parison. In this way there is obtained the delivery of air through the duct during the return travel to achieve the cleaning of the dispensing chamber and of the dispensing nozzle so as to prevent dripping of the foam and the development of mildew in case of a long interval before the next use. Alternatively, a frequency domain channel estimate for pilot subcarriers are converted to a time domain channel estimate and an improved frequency domain channel estimate is obtained based on the number of pilot subcarriers and a delay spread.