DSO221SRAB DSO221SRAB 11.2896M+-50 DSO221SRAB100.000MHZ DSO221SRDC 27MHZ DSO221SRDC27MHZ DSO221SW 8MHZ DSO221SW12.000MHZ DSO221SW12.288MHZ DSO221SW16.000MHZ DSO221SW20.000MHZ