Several measurements are required to verify that the performance of every pickup cartridge assembled on a production line meets its published specifications. Automatic testing makes faster and more accurate measurements possible, and with stored program control, statistical distributions of performance parameters in a production series can be computed. In addition, hard copy of test results, to be enclosed with the cartridge, can be obtained. A minicomputer-based production test system for stereo and quadraphonic cartridges is described, where, by employing a specially designed test record as signal source, the following parameters characterizing a cartridge are measured and compared against specifications: output voltage, channel difference, tracking ability, frequency response, and channel separation. With a reference cartridge calibrated by the two-speed method, variations in test record frequency response are measured automatically, and accounted for in test results. The system incorporates a strip printer for printout of calibration data, and a level recorder to plot frequency response. The total time, including handling, is less than 1 minute for the complete test of a cartridge.
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