The document, ARRL FMT Technique with FLEX-6000 Series Radios, by Ron Panetta, WB2WGH whhich can be downloaded from the FlexRadio web site describes in great detail how to use a FLEX-6000 software defined radio to participate in the ARRL Frequency Measuring Test (FMT). For more information on the ARRL FMT, please refer to the link Try the FMT.