ABSTRACT: This is the user guide of the Maury Microwave Precision TNC Coaxial Calibration Kit (DC to 18 GHz) for models 8650CK10/11 and 8650CK20/21. This series of Precision TNC coaxial calibration kits is designed to provide accurate calibrations of network analyzers in the DC to 18.0 GHz range. Each of these kits includes all the necessary calibration standards and associated hardware needed for the accurate calibration of most network analyzers.