Abstract: An arrangement for mechanically adjusting the oscillation frequency in a dielectric resonator oscillator which includes a base or support member, as a cover for the oscillator housing, involving two rotatable plates between which the aforesaid base is sandwiched. The base includes an opening extending therethrough, where a rotatable first plate overlies such opening on one side of the base, and a rotatable second plate overlies such opening on the opposite side of the base. The first rotatable plate includes an off-center opening adapted to receive a centrally disposed stem portion extending from the second rotatable plate, where a dielectric resonator is disposed off-center on the second rotatable plate and extends in an opposite direction to that of the stem portion. A fastening member encircles the stem portion and maintains the assembled rotatable first plate and rotatable second plate at a selected X and Y coordinate location.