HRC is a software to easily compute the voltage, current, impedance, SWR, power and loss values in every point along a transmission line and other circuits, from the antenna to the RTX and viceversa. It can be used, with the only aid of a VNA, to exactly determine the efficiency of an antenna tuner, so as to establish a standard way of comparing different couplers you may review. Due to the very different impedance values present on the antenna port of the tuner, HRC does not take into account just the S21 parameters, but makes full use of the scattering matrix.
