A system for making high frequency measurements on a DUT includes a high frequency measurement instrument; a plurality of DUT probes; a first coaxial cable having a center conductor and a coaxial conductor for connection between the instrument and a first DUT probe; and a second coaxial cable having a center conductor and a coaxial conductor for connection between the instrument and a second DUT probe, at least one of the first and second cables being selectively shortable between the respective center conductor and coaxial conductor at a location near the respective DUT probe.