Nonlinear signal distortion, caused by passive intermodulation (PIM), presents a major challenge to modern multi-carrier communications and radar systems. Reverse PIM products generated by discrete nonlinear sources are analyzed in this paper, and the means of PIM mitigation are proposed. The developed model is validated experimentally using an open-ended coaxial waveguide with a movable iron insert, which acts as a main PIM source. The PIM generation mechanisms revealed in this study have identified alternative means for PIM mitigation. A novel circuit, proposed in the paper, enables an effective reduction ofthe reverse PIM for more than 44 dB.