hello nmr wikier I am using Z-gradiant BBI probe on bruker AV-500 since last weak I am facing tuning and matching problem both by atma command and manually atmm command.ON atma command it is abroted in all standard sample and on atmm the coarse button did not arive only fine button active on proton channel while carbon channel work fine and befor reaching in mid of the curve the button reaches at end and curve goes away from center.I have tried by enlarging wbsw by 2o 40 60 but it is not working.I have also tried all command which are in BASH like atma coarse atma exact but the problem is still thair. Thanks for replaying in advance with best regard Feroon