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Representing the 3rd generation of CD jitter meters, the LE 1854 extend the range of this powerful performance gauge to meet the needs of rapidly expanding CD applications. Designed for disc mastering, disc production, player production and quality control, the instrument assists in production tuning, optimization and documentation.
RF levels and jitter readings are shown simultaneously with selectors to read 3T and 11T levels of the EFM (eight to fourteen modulation) signal. The sigma s measuring mode displays the amount of jitter error within ±1 standard deviation of the mean. This produces a near steady state meter reading to facilitate accurate measurements and adjustments. Displayed values are objective and not subject to the kind of interpretation errors experienced when viewing EFM signals on an oscilloscope. The LE 1854 reads jitter in Sigma values only. A polarity selector for jitter references the readings to either the rising (pit-to-land) or the falling (land-to-pit) transitions to show asymmetric differences. Signal processing partially corrects 3T asymmetry to minimize the effect on the jitter reading at higher speeds. In addition to 3T and 11T level readings, a buffered output allows oscilloscope observation of ratio and symmetry.
Of particular value in production and QC operations, the GO/NO GO judgement section provides adjustable thresholds for 3T and 11T peak levels as well as jitter limits. Front panel GO/NO GO indicators are augmented by rear panel outputs for remote indicators or alarms. DC meter analogs are also provided on the rear panel for remote level and jitter indicators. |
