If the visual inspection shows that a connector requires cleaning, see the application note 1MA99. The application note provides information on the means you can use and how to clean the thread and the inside of the connector.
Connecting to I/Q
The I/Q input connectors are female SMA connectors at rear panel of the R&S SZU, see "I/Q input connectors". They are color coded to assign the connectors and the matching cables.
Inspect the I/Q connectors of the R&S SZU visually to check that they are clean, undamaged and mechanically compatible.
Thus, you prevent insertion loss and mismatch, and even premature wear of the connectors.
Note:
Starting on the left with the BB I In connector, select the color matching differential I/Q cable from the differential IQ/USB cable set that was delivered with the R&S SZU.
Inspect the connector of the cable visually as described in step step 1.
Carefully align the connector of the cable and the connector of the R&S SZU along a common axis.
Mate the connectors along the common axis until the male pin of the cable connector engages with the female socket of the instrument connector.
Turn the nut of the outer cable connector until the connectors are coupled.
Tighten the nut as follows:
Use a calibrated torque wrench suitable for the type of connector.
Hold the opposite connector part stationary with a spanner.
Tighten the nut to the specified limit of 0.56 Nm.
Excessive tightening can damage the connectors. Too loose tightening can lead to inaccurate measurement results.