Tektronix p2221 passive 1x 10x voltage probe tektronix p2221 p the tektronix p2221 is a 200mhz passive voltage probe that permits selection of 1x or 10x attenuation using a switch located on the probe head this probe will provide high reliability and accuracy for basic oscilloscope measurements the p2221 is compatible with mso2000 and dpo2000 series oscilloscopes p p applications relative low frequency measurements low frequency computer and telecom measurements power supplies and l