The present invention discloses a method for pilot channel tracking based on multipath channel barycenter tracking loop, comprises steps of evaluating multipath fading channel parameters, calculating the barycenter of a multipath energy window, and loop filtering and adjusting the phase of spread spectrum sequence codes. The PLL circuit includes an oscillator control circuit for increasing and decreasing the PLL output frequency signal, a frequency detector for detecting a phase shift between the reference signal and the PLL output signal and produces an error signal, and a fast lock circuit for detecting when the output frequency signal passes the selected multiple of the reference signal. A second lead is mechanically coupled to a second surface of the die at a first surface of the second lead. An adjustment device provides for moving the linear stop from an inmost position to an outmost position, and simultaneously lowering the camming foot into the hole in the floor and moving the camming foot to urge the module into a fully seated position wherein the module is moved against the linear stop when the linear stop is in its outmost position. The apparatus includes a plate of sufficient thickness to impart strength in supporting a solid particle bed, and is milled to have narrow slots allowing the flow of fluid through the plate, while preventing the passage of catalyst through the plate.