A technique for setting the initial servo track pitch for a servo system
of a hard disk drive (HDD) is based on using a secondary actuator, such
as a microactuator or a milliactuator. The actuator of the HDD is
positioned against a crash stop and a burst pattern is written on a hard
disk while the read/write head is in a first position. A bias voltage of
the secondary actuator is incrementally changed to change the position of
the read/write head and a burst pattern is written for each change. The
overlap is determined as a sum of the averaged amplitudes of the burst
patterns that are adjacent to a selected burst pattern divided by the
averaged amplitude of the selected burst pattern. The process is
terminated when the determined overlap for each selected burst pattern is
within a selected criterion of a target overlap value.