DSO221SR32.768KHZ DSO221SR33.000MHZ DSO221SR50.000MHZ DSO221SR54.000MHZ DSO221SR72.000MHZ DSO221SR8.000MHZ DSO221SRAA33.3MHZ DSO221SRAB DSO221SRAB 11.2896M+-50 DSO221SRAB100.000MHZ