Abstract: An HGA loader provides HGAs, in succession, to a multiple workstation head tester. An HGAs carrier station receives HGAs to be tested. An alignment station on the base includes an alignment surface which selectively rotates about an alignment axis. A camera generates images of an HGA on the alignment surface, which is rotated so that the HGA has a desired spatial orientation which is maintained as the HGA is transferred to an HGA testing workstation. A received, oriented HGA is positioned to enable read/write test operations on a disk rotating on an adjacent spinstand. To effect the successive position operations, a transporter includes a track overlying the workstations, and a carriage movable along the track, to pass from workstation to workstations. The loader is automatically operative under the control of a controller.

Abstract: An HGA loader provides HGAs, in succession, to a multiple workstation head tester. An HGAs carrier station receives HGAs to be tested. An alignment station on the base includes an alignment surface which selectively rotates about an alignment axis. A camera generates images of an HGA on the alignment surface, which is rotated so that the HGA has a desired spatial orientation which is maintained as the HGA is transferred to an HGA testing workstation. A received, oriented HGA is positioned to enable read/write test operations on a disk rotating on an adjacent spinstand. To effect the successive position operations, a transporter includes a track overlying the workstations, and a carriage movable along the track, to pass from workstation to workstations. The loader is automatically operative under the control of a controller.

Abstract: Radially-coherent data reading from, and data writing to, a magnetic disk use non-coherently written synchronization signals on the disk. In a form, the radially-coherent data reading and writing is performed using a magnetic head/disk tester which includes a spinstand for supporting a spinning magnetic disk, a magnetic head assembly, a write channel network for generating a write data signal for application to a write element of the magnetic head, a read channel for receiving a read-back signal from a read element of the magnetic head assembly, and a signal processing system that analyzes a read-back signal from a disk and provides synchronization signals for radially-coherent data reading and data writing.

Abstract: Radially-coherent data reading from, and data writing to, a magnetic disk use non-coherently written synchronization signals on the disk. In a form, the radially-coherent data reading and writing is performed using a magnetic head/disk tester which includes a spinstand for supporting a spinning magnetic disk, a magnetic head assembly, a write channel network for generating a write data signal for application to a write element of the magnetic head, a read channel for receiving a read-back signal from a read element of the magnetic head assembly, and a signal processing system that analyzes a read-back signal from a disk and provides synchronization signals for radially-coherent data reading and data writing.

Abstract: Disclosed is a method of equalization of a vector/signal analyzer including: providing a structured test signal within a selected frequency range. The structured test signal includes a plurality of frequency components each having a respective amplitude and phase. The method includes inputting the test signal to the analyzer; the analyzer operating to condition the test signal; determining information representative of frequency distortion of the conditioned test signal introduced by the analyzer; generating a set of equalization coefficients based on the information representative of the frequency distortion, the set of coefficients corresponding to the selected frequency range; and storing the set of equalization coefficients and the correspondence of the set of coefficients to the selected frequency range.

Abstract: Disclosed is a method of measuring frequency distortions characteristics of a device under test, the device configured convert an input signal in an input frequency range to an output signal in a different output frequency range. The method includes, for each test frequency fi, where i=1, . . . , N and N a positive integer, in a selected frequency range, providing a corresponding test signal with multiple frequency components having a measurement component with a frequency fi, a first reference component with a frequency fA, and a second reference component with a frequency fB; inputting the test signals into the device under test; measuring output test signals at the output of the device under test corresponding to the input test signals; and determining, for each test frequency fi, information representative of frequency distortions based on the corresponding input test signal and the corresponding output test signal.

Abstract: Disclosed is a method of equalization of a vector/signal analyzer including: providing a structured test signal within a selected frequency range, the structured test signal comprising a plurality of frequency components each having a respective amplitude and phase; inputting the test signal to the analyzer; the analyzer operating to condition the test signal; determining information representative of frequency distortion of the conditioned test signal introduced by the analyzer; generating a set of equalization coefficients based on the information representative of the frequency distortion, the set of coefficients corresponding to the selected frequency range; and storing the set of equalization coefficients and the correspondence of the set of coefficients to the selected frequency range.

Abstract: Disclosed is a method of measuring frequency distortions characteristics of a device under test, said device configured convert an input signal in an input frequency range to an output signal in a different output frequency range. The method includes, for each test frequency fi, where i=1, . . . ,N and N a positive integer, in a selected frequency range, providing a corresponding test signal with multiple frequency components comprising a measurement component with a frequency fi, a first reference component with a frequency fA, and a second reference component with a frequency fB; inputting said test signals into the device under test; measuring output test signals at the output of the device under test corresponding to the input test signals; and determining, for each test frequency fi, information representative of frequency distortions based on the corresponding input test signal and the corresponding output test signal.

Abstract: Analysis of a read back signal in a magnetic recording device is disclosed. The read back signal is converted to a digital read back signal, and a low frequency component of the digital read back signal is restored. A sample clock is recovered from the restored digital read back signal, and the restored digital read back signal is averaged using the recovered sample clock. A timing error is calculated based at least in part on the averaged restored digital read back signal.

Abstract: Analysis of a read back signal in a magnetic recording device is disclosed. The read back signal is converted to a digital read back signal, and a low frequency component of the digital read back signal is restored. A sample clock is recovered from the restored digital read back signal, and the restored digital read back signal is averaged using the recovered sample clock. A timing error is calculated based at least in part on the averaged restored digital read back signal.