Abstract: Apparatus for detecting data in a sensor signal generated by a read sensor in a local probe data storage device comprises a differentiation for subtracting a value of the sensor signal from the succeeding value of the sensor signal to generate a ternary difference signal; and a convertor connected to the differentiator for converting the difference signal into a binary output signal indicative of the detected data. A local probe data storage device comprising such apparatus is also described.

Abstract: An improvement to a phase controlled mechanical oscillator consists of a balancing network which generates a feedback signal from two different input signals with adjustable weights. One of these input signals is directly derived from the oscillator signal, the other is derived from a phase tracking loop. Using the balancing network, adjustments can be made to adapt the feedback to the mechanical properties, in particular to the Q factor, of the oscillator. In a preferred embodiment, all major components are working at an intermediate frequency level, generated by mixing the oscillator frequency with a reference frequency. As a major advantage of this (heterodyne) mixing, the bandwidth of any applied frequency detector can be narrowed, thus increasing the achievable signal-to-noise ratio.