A tunable slope equalizer comprising a waveguide (e.g., rectangular waveguide) and posts (e.g., cylindrical posts) configured to move inside the internal cavity of the waveguide is presented. The degree of depth the posts may be inserted into the cavity of the waveguide may determine the orientation of the frequency response slope, e.g., positive or negative, and the maximum (or approximately maximum) insertion loss at minimum (or approximately minimum) or maximum (or approximately maximum) operating frequency, respectively. Being a mechanical device, the tunable slope equalizer may be fabricated at a relatively higher level of precision, leading to lower variances in performance over production.