A system for reducing written-in high-frequency repeatable run-out track
mis-registration occurring during writing of servo information onto a
hard disk implementable in a hard disk drive is described. The system
includes an excitation frequency adjuster enabled to adjust excitation
frequencies away from mechanical modes to provide desired rotation speed
of a servo track writer. The mechanical modes are present in said hard
disk drive. The system also includes an excitation level adjuster enabled
to adjust excitation level to provide a desired DC gain level associated
with a motor controller of the servo track writer. The system further
includes an excitation frequency content adjuster enabled to adjust
excitation frequency content to provide desired current profile of the
motor controller, such that a reduction of written-in high frequency
repeatable run-out track mis-registration is realized.