J. Kissel In order to improve the uncertainty on the parameters the lines are measuring, I've adjusted the line heights of a good fraction of the calibration lines. I'll leave them in like this overnight, and see if we get the expected improvement in the uncertainty (especially as reported by the front-end). Line Freq Former New PCALY 36.7 750 500 331.9 2900 5000 7.9 20000 5000 ETMY UIM 33.7 60 180 ETMY PUM 34.7 27 81 Note the reduction of the 7.9 and 36.7 Hz modes. We don't always increase line heights ;-).