Installation Note N9038-90018 23Option HL4 - High Performance Digital Signal Processing UpgradeRear Panel Installation50.Remove the hole plug that is installed in the AUX IF OUT port of the MP6 Rear Panel.51.Refer to Figure 5. Using the 5/16” nut driver insert the SMA end of the new W22 cable(8121-1859) into the rear panel AUX IF OUT port (3). Torque to 10 inch-lbs.52.While positioning the W22 cable between the two left chassis side panels install the MP6 RearPanel (1) onto the rear of the instrument.53.Attach the MP6 Rear Panel (1) to the instrument with the thirteen pan head screws (4)(0515-0372). Torque to 9 inch-lbs.54.If it exists, using the 3/16” nut driver attach the W9 LISN Control Ribbon Cable to the rearpanel AUX I/O port (6) with the two new hex standoffs (7) (0380-1858). Torque to 9 inch-lbs.55.Using the 9/16” nut driver attach the W21 External Reference Input Cable to the rear panelEXT REF IN port (2). Torque to 21 inch-lbs.56.Route the W22 Aux IF Out cable along the top of the instrument fans between the two leftchassis side panels and connect it to J1100 of the A15 Enhanced Front End Control boardassembly as shown in Figure 13. Leave the majority of the cable slack near the instrument rearpanel so it can be removed easier in the future.