DSO751SR-64.000MHZ DSO751SRAB-66.6666MHZ DSO751SU-80.0000M-50PPM DSO751SV 80MHZ DSO751SV 1.8432MHZ DSO751SV 10.000MHZ DSO751SV 100.000MHZ DSO751SV 12.288MHz DSO751SV 13.500MHz DSO751SV 16.000MHZ