5 Selecting the Communications Port © Tait Electronics Limited April 2006Power AmplifierPowerManagement UnitSelecting the Communications PortBefore you connect to a base station, you should first define thecommunications (COM) port that you want to use.To select the COM port1. Select Tools > Options.2. Select the port that you want to use from the COM Port list.Note: The available COM ports are detected by the program andappear in the list.3. Click OK.The COM port you selected is now shown on the status bar.Connecting to a Reciter Outside the SubrackField calibration procedures require access to the tuning holes, so you need toremove the reciter from the subrack and connect to it using a CTU.Equipment ■ Calibration and test unit (CTU)■ An IBM compatible PC■ 10-30 V DC power supply■ 16-way cable■ RS-232 cableProcedure Connection Equipment RequiredCalibrating the PA bias Inside subrack None requiredCalibrating the forward &reverse detector bias voltagesInside subrack None requiredCalibrating the PA power Inside subrack None requiredProcedure Connection Equipment RequiredOutput voltage calibration Inside subrack Digital multimeter