In a method of actively controlling slider fly height, a modulated radio
frequency (RF) carrier signal is received from a slider. The modulated RF
carrier signal comprises an amplitude modulated component which is
modulated onto the modulated RF carrier signal by vibration of the
slider. The amplitude associated with the amplitude modulated component
is measured. Thermal fly height control (TFC) voltage generation is
controlled by feeding back on the amplitude. A TFC voltage to apply to
the slider is generated such that a selected amplitude of the amplitude
modulated component is achieved and maintained. The selected amplitude is
associated with a particular preselected fly height of the slider above a
surface of a disk. The TFC voltage is provided to the slider.