Abstract: A filter including a cavity, a resonator structure and having a plastic resonator support and plastic tuning assembly suitable for both manual and automatic tuning applications. The dielectric resonator structure comprises a substantially cylindrical ceramic resonator, and a plastic support having a plurality of spaced apart elements diverging from a shoulder of the plastic support, each of the elements terminating in a cantilevered stop, the cantilevered stops holding the ceramic resonator in a fixed relationship with respect to the plastic support and the cavity. A resonator tuning assembly is provided that comprises a substantially cylindrical ceramic tuning element and a plastic tuning shaft having a coupling means at a first end and being threaded along a portion of its length. A ceramic tuning element is affixed to the shaft at a second end.