MXi005U AMPLIFIER TECHNICAL SERVICE MANUAL LARCAN INC. 228 AMBASSADOR DRIVE MISSISSAUGA, ONTARIO CANADA L5T 2J2 PHONE: (905) 564-9222 FAX: (905) 564-9244 EMAIL: techservices@larcan.
MXi005U OPERATIONS AND MAINTENANCE CONTENTS 1 MXi005U AMPLIFIER.....................................................................................................................................................1 2 MXi CONTROLLER ........................................................................................................................................................2 2.1 MXi005U CONTROL BOARD ASSEMBLY AND JUMPER SETTINGS ....................................................................
MXi005U OPERATIONS AND MAINTENANCE FIGURE 8 TEST EQUIPMENT SETUP .............................................................................................................................................13 FIGURE 9 MXI005U CONTROLLER BOARD ASSEMBLY ..............................................................................................................
MXi005U OPERATIONS AND MAINTENANCE 1 MXi005U AMPLIFIER The RF section of the MXi005U Amplifier consists of a heatsink assembly that includes three cascaded broadband amplifier modules and a directional coupler. Figure 1 shows the layout of this assembly. Figure 1 MXi005U Amplifier Heatsink Assembly Also mounted on the heatsink is a thermal switch that protects the amplifier from over temperature conditions.
MXi005U OPERATIONS AND MAINTENANCE 2 MXi CONTROLLER The MXi control board (Assembly 31C1897) is a single-circuit assembly that provides all of the control functions required for the MXi series of transmitters on a single circuit board. This board can be configured for a number of different transmitter types, power levels, transmission standards and options. Figure 2 MXi Controller The MXi control board provides local front panel interface via ON/OFF and RESET buttons.
MXi005U OPERATIONS AND MAINTENANCE E2 Not used in the MXi005U transmitter Setting = no jumper installed E3 Not used in the MXi005U transmitter Setting = no jumper installed E4 Not installed in this assembly E5 Front Panel ON/OFF button Mode This jumper determines the function of the Front Panel ON/OFF button If E5 is in the ‘INT’ position, Remote ON/OFF Controls are disabled, Local Controls Only If E5 is in the ‘EXT’ position, Remote ON/OFF Controls are enabled, Local OFF Control Only More detail o
MXi005U OPERATIONS AND MAINTENANCE Setting = not Installed for all MXi005U transmitters E18 Direct Vswr Relay reset from the Remote Reset Command This jumper allows the Remote Reset Command to directly clear the VSWR trip relay Setting = Installed for all MXi005U transmitters E19 Forward Power Detection Type Setting = PK for all MXi005U transmitters 2.
MXi005U OPERATIONS AND MAINTENANCE Figure 4 Remote Command Inputs 2.3.2 Remote Telemetry Outputs There are only four remote telemetries available to the operator, these being RF forward power, RF reflected power, AGC voltage and Cutback voltage. In the table of remote signals, all remote commands have a RT_ prefix. The only further note on the telemetry outputs concern the AGC and Cutback telemetry levels. These levels are normally sent to the PreAmp attenuator and range from 0V to about 10V.
MXi005U OPERATIONS AND MAINTENANCE can be connected to maximum 30 VDC output. The active (true) condition whether high or low will depend on the specific status output. Figure 6 Remote Status Outputs 2.3.4 External1 Interlock There is a pair of terminals on the D-connector that is used for an external interlock to interface to any site alarms or shutdown conditions. These pins would expect a dry contact that is closed when there is no error condition.
MXi005U OPERATIONS AND MAINTENANCE The external1 interlock contacts are available in two separate locations. The first location is on the two pin terminal block on the rear of the MXi transmitter chassis. This is the more likely and convenient place for the External1 interlock to be connected. A second parallel set of contacts is located on the 15-pin Telemetry D-connector on the rear of the MXi transmitter chassis.
MXi005U OPERATIONS AND MAINTENANCE 3 AMPLIFIER INSTALLATION AND STARTUP The MXi Amplifier was fully tested at LARCAN before it was delivered. Under normal circumstances, the transmitter can be fully operational with minimal setup when turned ON. However, a good practice is to take the “start from scratch” approach, which means that you should take precautionary measures before the amplifier is allowed to run at full rated power. These important steps will avoid any catastrophic failures at start-up.
MXi005U OPERATIONS AND MAINTENANCE 3.3 BEFORE TURNING THE AMPLIFIER ON Check that all of the following conditions are met: 1. Modulator is Ready. • Usually in the application of AC, the Modulator goes through its warm-up sequence. Ensure that it has done so. 2. MXi CONTROLLER is ready. • If there were prior faults, clear them by pushing the RESET button. 3. INTERLOCKS are closed or OK. • Interlocks and Status are OK. 4. The TX is OFF. • Push the Front Panel ON/OFF button so that it is NOT pushed in.
MXi005U OPERATIONS AND MAINTENANCE 4 TEST AND TROUBLESHOOTING 4.1 BENCH TEST PROCEDURES The following procedures are test instructions for the amplifier modules comprising the MXi amplifier. 4.1.1 Front-End Module Bench Test Procedure • Connect a +28V (1A current limit) power supply to TP2. • Apply a 0dBm (1mW) RF input to the amplifier. • Turn RV2 fully clockwise. The front-end should have a gain of 13dB. Adjusting RV2 from one extreme to the other should vary the gain by a minimum of 20dB.
MXi005U OPERATIONS AND MAINTENANCE • • Apply +28V to the B+ terminal. Monitor the current and adjust R12 counter clockwise (CCW) for a total current of about 0.6A + 0.05A. • Proceed to the next step if a network analyzer or similar equipment is available. RF SWEEP: Adjust C7 for best frequency response. With the bias set at 0.6A, the gain in the range of 470MHz to 860 MHz should be 15 to 16dB. 4.
MXi005U OPERATIONS AND MAINTENANCE 5 MAINTENANCE Equipment which is regularly and carefully maintained is far less likely to be subject to sudden failure than that which is operated without regard to basic maintenance requirements. A detailed preventive maintenance program should be established to ensure that the original efficiency and picture quality is maintained throughout the life of the equipment.
MXi005U OPERATIONS AND MAINTENANCE 6 TEST EQUIPMENT SETUP Figure 8 Test Equipment Setup PUB06-76 Rev 2 July 18, 2007 06-76-13 MXi005U Operations and Maintenance
MXi005U OPERATIONS AND MAINTENANCE 7 SPECIFICATIONS Specifications are subject to change without notice. 7.1 ELECTRICAL AC Line Input .....................................................................................................................90 to 264VAC, 50 to 60Hz Power Consumption, black picture + 10% aural ................................................................................. 120VA (typical) 7.2 ENVIRONMENTAL Ambient Temperature ..................................................
MXi005U OPERATIONS AND MAINTENANCE Figure 9 MXi005U Controller Board Assembly PUB06-76 Rev 2 July 18, 2007 06-76-15 MXi005U Operations and Maintenance
MXi005U OPERATIONS AND MAINTENANCE NOTES PUB06-76 Rev 2 July 18, 2007 MXi005U Operations and Maintenance
