Apparatuses, methods of assembling a resonator, and methods of tuning a resonator are provided. An example apparatus may include at least one resonator comprising a resonator hole defined within the resonator and defining an inner wall of the at least one resonator, a tuning cover comprising at least one hollow rod, and a tuning element comprising a bottom flanged portion. The tuning element may be configured to be inserted into the at least one hollow rod and the bottom flanged portion is configured to cover at least a bottom portion of the hollow rod. The bottom flanged portion of the tuning element is configured to be positioned between the at least one hollow rod and the inner wall of the at least one resonator.