A wheeled cart like ball dispensing device for storing, transporting, and dispensing soccer balls by delivering soccer balls to a player in a variety of delivery modes for simulating game conditions for a player to practice responding to a variety of different shots. A buffer amplifier is inserted in series into a path through which a signal is transmitted. Alternatively the mandrel comprises a self-supporting metal material jacket. At least three spectra are obtained with one after a delay at above twenty degrees Celsius, and at least one at power levels different from the others.