Assembly Instructions

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MXI1503-2004 OPERATIONS AND MAINTENANCE

PUB13-10 Rev 1 1

CONTENTS

1 THE MXI1503-2004 TRANSMITTER ............................................................................................................................ 3

2 MXi AMPLIFIER ASSEMBLY ....................................................................................................................................... 4

3 MXi AMPLIFIER CONTROLLER ................................................................................................................................ 5

4 MAIN CONTROL CHASSIS ........................................................................................................................................... 6

5 AMPLIFIER INSTALLATION AND STARTUP .......................................................................................................... 7

5.1 BEFORE APPLYING AC TO THE UNIT ............................................................................................................................ 7

5.2 APPLYING AC TO THE UNIT .......................................................................................................................................... 7

5.3 BEFORE TURNING THE AMPLIFIER ON ......................................................................................................................... 7

5.4 AMPLIFIER ON SEQUENCE ............................................................................................................................................ 8

5.4.1 Turning ON the Transmitter ................................................................................................................................ 8

5.4.2 TYPICAL DATA read on the LCD ....................................................................................................................... 9

6 TEST AND TROUBLESHOOTING ............................................................................................................................. 10

6.1 BENCH TEST PROCEDURES ......................................................................................................................................... 10

6.1.1 Front-End Module, 21B2860G7, Bench Test Procedure ................................................................................... 10

6.1.2 Driver Pallet, 21B2708G3, Bench Test Procedure ............................................................................................ 10

6.1.3 PA Pallet 21B2729G1 Bench Test Procedure.................................................................................................... 10

6.1.4 Amplifier AGC Setup .......................................................................................................................................... 10

6.2 BASIC TROUBLESHOOTING TECHNIQUES .................................................................................................................... 12

6.2.1 No RF Output ..................................................................................................................................................... 12

6.2.2 Output Reduced by 45% (for MXi1503) or 60% (for MXi2004) ........................................................................ 12

7 MAINTENANCE ............................................................................................................................................................. 13

7.1 DAILY ......................................................................................................................................................................... 13

7.2 MONTHLY ................................................................................................................................................................... 13

7.3 SEMI-ANNUALLY AND ANNUALLY ............................................................................................................................. 13

7.4 TRANSMITTER COOLING SYSTEM ............................................................................................................................... 13

8 SERVICE ......................................................................................................................................................................... 14

8.1 REMOVING THE FAN ARRAY ....................................................................................................................................... 14

8.2 REPLACING THE ENTIRE FAN ARRAY ......................................................................................................................... 15

8.3 REPLACING A SINGLE FAN .......................................................................................................................................... 15

Summary of content (20 pages)

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MXI1503-2004 OPERATIONS AND MAINTENANCE CONTENTS 1 THE MXI1503-2004 TRANSMITTER ............................................................................................................................ 3 2 MXi AMPLIFIER ASSEMBLY ....................................................................................................................................... 4 3 MXi AMPLIFIER CONTROLLER .............................................................................................................
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MXI1503-2004 OPERATIONS AND MAINTENANCE FIGURES FIGURE 1 MXI AMPLIFIER HEATSINK ASSEMBLY ........................................................................................................................ 4 FIGURE 2 MXI CONTROLLER ........................................................................................................................................................ 5 FIGURE 3 MAIN MENU......................................................................................................
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MXI1503-2004 OPERATIONS AND MAINTENANCE 1 THE MXI1503-2004 TRANSMITTER This publication describes the operation and maintenance of both the MXi1503 and MXi2004. These transmitters are very similar, only differing in the number of amplifier and power supply modules. The MXi1503 is comprised of 3 Amplifier and 3 Power Supply modules where as the MXi2004 is comprised of 4 Amplifier and 4 Power Supplies. In both cases each power supply is connected to an individual amplifier.
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MXI1503-2004 OPERATIONS AND MAINTENANCE 2 MXi AMPLIFIER ASSEMBLY Each MXi Power Amplifier Assembly consists of a control board, fan-cooled heatsink and ten printed circuit board sub-assemblies. The first module is a pre-amplifier, known as the Front-End Module. Next is the Driver pallet, which is biased so as to pre-correct for the non-linearity in the final amplifier stage. The next stage is a five-way splitter that splits the RF power so it can be fed to the PA pallets.
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MXI1503-2004 OPERATIONS AND MAINTENANCE 3 MXi AMPLIFIER CONTROLLER The MXi amplifier control board (Assembly 31C1897) is a single-circuit assembly that provides all of the control functions required for the MXi series amplifier on a single circuit board. This board can be configured for a number of different amplifier types, power levels, transmission standards and options.
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MXI1503-2004 OPERATIONS AND MAINTENANCE 4 MAIN CONTROL CHASSIS The main control chassis located above the RF Amplifiers contains the main control board, LCD touch screen and RF splitter. The main control board (Assembly 31C1972) is a single-circuit assembly that provides all of the communications and controls to the MXi Amplifiers on a single circuit board. The controller uses a RS-232 connection to communicate with the Amplifiers.
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MXI1503-2004 OPERATIONS AND MAINTENANCE 5 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 one 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.
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MXI1503-2004 OPERATIONS AND MAINTENANCE  2. Usually in the application of AC, the modulator goes through its warm-up sequence and may take a few seconds before it is ready. POWER METERING is at Zero.  3. On the LCD (see Main Menu display in Figure 6), the PWR should be at 000% and the STATUS should be TX IS OFF, NORMALLY. MAIN CONTROLLER is ready.  4. If there were prior faults, clear them by pushing the RESET button on the power supply chassis front panel. INTERLOCKS are closed or OK.
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MXI1503-2004 OPERATIONS AND MAINTENANCE 2. Monitor the +50V power supply voltage and currents on the LCD. Check that the power supplies are operating by pressing the P/S touch button. The voltage readings should be about 50V and the currents should be about 45-50 Amps per module under full power. ALLOW THE AMPLIFIER SOME WARM-UP TIME! Only after the transmitter has been ON for approximately 15 minutes should you perform the fine adjustments.
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MXI1503-2004 OPERATIONS AND MAINTENANCE 6 TEST AND TROUBLESHOOTING 6.1 BENCH TEST PROCEDURES The following procedures are test instructions for the amplifier modules comprising the MXi amplifier. 6.1.1 Front-End Module, 21B2860G7, Bench Test Procedure  Connect +32V to TP2. Limit the power supply current 1A. Check that the current consumption is about 0.30A.  Apply a 0dBm (1mW) RF input to the amplifier.  Turn RV2 fully clockwise. The Front-End module should have a gain of about 14dB.
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MXI1503-2004 OPERATIONS AND MAINTENANCE  Turn the Amplifier ON with the drive level from the Modulator and up-converter, or Channel Processor turned all the way down  Increase the output power to 110%, using the output level control in the Exciter or Channel processor. Enable the AGC by inserting the AGC jumper, E16, on the control board.
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MXI1503-2004 OPERATIONS AND MAINTENANCE 6.2 BASIC TROUBLESHOOTING TECHNIQUES One of the best tools in troubleshooting is knowing what the nominal figures or typical values of the MXi amplifier are when it is at its normal performance. If a fault condition occurs, then you can compare the data taken previously with the present conditions and come up with a reasonable conclusion about what is at fault. The following describes some fault conditions and possible solutions. 6.2.
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MXI1503-2004 OPERATIONS AND MAINTENANCE 7 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.
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MXI1503-2004 OPERATIONS AND MAINTENANCE 8 SERVICE The MXi contains few user-serviceable parts; the modular surface-mount design makes module replacement and/or factory repair the most efficient repair method. The service most likely to be performed by users is the replacement of the fan array. 8.1 REMOVING THE FAN ARRAY The MXi fan array consists of four 4” muffin-type fans which are attached to the mounting plate.
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MXI1503-2004 OPERATIONS AND MAINTENANCE Figure 8 Fan Array 8.2 REPLACING THE ENTIRE FAN ARRAY In the event of a fan failure, LARCAN recommends replacing the entire array, as all fans have a similar lifespan. 1. Remove the fan array as described in Section 8.1. 2. Slide the new fan array into the MXi. The power connection is aligned so that it connects when the mounting plate is fully in place. 3. Insert and tighten the three mounting screws. Note: Screws only need to be snug; do not over tighten. 8.
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MXI1503-2004 OPERATIONS AND MAINTENANCE Figure 10 RF Flow for MXi1503 PUB13-10 Rev 1 16
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MXI1503-2004 OPERATIONS AND MAINTENANCE Figure 11 RF Flow for MXi2004 PUB13-10 Rev 1 17
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MXI1503-2004 OPERATIONS AND MAINTENANCE Figure 12 MXi1503 Interconnect Diagram PUB13-10 Rev 1 18
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MXI1503-2004 OPERATIONS AND MAINTENANCE Figure 13 MXi2004 Interconnect Diagram PUB13-10 Rev 1 19
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MXI1503-2004 OPERATIONS AND MAINTENANCE NOTES PUB13-10 Rev 1