The oscillator circuit of a quartz crystal timepiece is provided with a tuning capacitor device consisting of a stepped variable capacitor and a continuously variable capacitor connected in parallel with each other and in series with said quartz crystal.

In a circuit particularly suited for producing oscillating signals and including a parallel coupled continuous variable capacitor and a step variable capacitor, the improvement comprising said step variable capacitor, and continuously variable capacitor being mounted to a base plate, first and second lower electrodes mounted on said base plate, and means mounted on said base plate electrically connecting said lower electrodes, said step variable capacitor being defined by a fixed dielectric mounted on said first lower electrode, and a plurality of upper electrodes mounted on said fixed dielectric, each of said electrodes having a different area overlapping said lower electrodes, a rotatable electrically conductive first switch contact member selectively positionable in electrical engagement with one of said upper electrodes, and said continuously variable capacitor being defined by an electrically conductive shaft rotatably mounted on said base plate out of electrical engagement with said first and second lower electrodes; a rotatable dielectric mounted for rotation with said shaft partly overlapping said second lower electrodes; a rotatable upper electrode supported by said rotatable dielectric in variable overlapping relation to said second lower electrode and electrically connected to shaft; said switch contact being supported by and electrically connected to said electrically conductive shaft.