TB9300 Installation and Operation Manual Replacing Modules 109© Tait Limited March 20168.4 Replacing a Power AmplifierNotice Before removing a PA, disconnect the DC input and RF inputfirst, followed by the RF output. After refitting the PA, reconnect the RFoutput first, followed by the RF input, and then the DC input.Removal 1. If you have not already done so, carry out the instructions in “Pre-liminary Disassembly” on page 105.2. At the front of the PA, unplug the DC input cable b and the RF inputcable c, and move both cables to one side. Unplug both ends of thesystem control bus cable d and remove it.3. At the rear of the PA, unplug the RF output cable.4. Loosen the screw securing the retaining clamp(s) e and rotate theclamp(s) through 90° to clear the module.5. Slide the PA out of the subrack, taking care not to damage any of thecables.Refitting 1. Slide the replacement PA into the subrack and secure it with theretaining clamp(s).2. At the rear of the PA, connect the RF output cable.3. At the front of the PA, connect the RF input cable, followed by theDC input cable.4. Reconnect all the other front and rear panel cables previouslydisconnected. Ensure the front panel cables are positioned correctly,and retained where required by the cable retaining clips in the top ofthe subrack (refer to “Appendix B – Inter-Module Connections” onpage 119).5. Tighten the nut on the SMA connector to a torque of 5lbf·in(0.6N·m).be dc bbd de cee(obscured)50W PA 100W PA
