The Tektronix 067-0609-00 is a common-mode rejection tester for 7000-series scopes which is used in conjunction with the 067-0587-00 Signal Standardizer Fixture to determine the CMRR of 7000-Series mainframe vertical interface amplifiers.
The 067-0609-00 CMR checker plugs into both mainframe vertical connectors at the same time. It accepts the 067-0587-00 Signal Standardizer through the left vertical compartment of the mainframe. The 067-0609-00 routes the CW signal from the 067-0587-00 to both mainframe vertical inputs, maintaining 50 Ω terminations to the signal standardizer. Precision-length coaxial cables introduce time delay to equalize arrival time of waveforms to each vertical connector.