A system for the estimation of the complex gain of a transmission channel is designed for parallel type modulatorsdemodulators that can be used in digital radio broadcasting. The air gun includes a quick load port for inserting projectiles into the gun chamber, and a compressed air circuit including an air control valve operated by a trigger for admitting a compressed air charge into the chamber, and for venting the chamber to ambiance on release of the trigger. Some embodiments allow tiles to be individually addressed, globally addressed, or addressed based on their tile types. The values added by each accumulator is a set of values starting with the value at the offset corresponding to the accumulator. In one aspect, information stored in the warehouse may be network management data. The dosage form does not contain an enteric coating.