TSM20-378 MXi030U 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.
MXi030U TECHNICAL SERVICE MANUAL TSM20-378 MXi030U TECHNICAL SERVICE MANUAL CONTENTS 1 INTRODUCTION .............................................................................................................................................................1 2 SAFETY NOTICES...........................................................................................................................................................2 2.1 BERYLLIUM OXIDE WARNING ................................................
MXi030U TECHNICAL SERVICE MANUAL 7 TEST EQUIPMENT SETUP..........................................................................................................................................12 8 SPECIFICATIONS .........................................................................................................................................................13 8.1 8.2 8.3 8.4 8.5 ELECTRICAL ............................................................................................................
MXi030U TECHNICAL SERVICE MANUAL 2.2 JUMPER OPTIONS ..........................................................................................................................................................4 2.2.1 BDM Slide Switch S2 ...........................................................................................................................................4 2.3 FRONT PANEL AND CONTROL INDICATORS ..................................................................................................
MXi030U TECHNICAL SERVICE MANUAL 3.6 4 GENERAL SCREEN ......................................................................................................................................................25 SETUP PROCEDURES ..................................................................................................................................................27 4.1 RF DETECTOR .........................................................................................................................
MXi030U TECHNICAL SERVICE MANUAL 1 INTRODUCTION This Technical Service Manual contains publications (PUBs) describing the technical details of the MXi030U amplifier, as well as the overall operating instructions, including the bench test procedures of the amplifier stages incorporated in this unit. It also covers the transmitter’s start-up operation, and troubleshooting, as well as basic transmitter maintenance guidelines.
MXi030U TECHNICAL SERVICE MANUAL 2 SAFETY NOTICES This section provides general guidance and information for the operation, maintenance, and service personnel who are familiar with the hazards of working with high-powered electronic circuits. This manual does not detail all of the safety precautions which should be observed when servicing this or any other electronic equipment.
MXi030U TECHNICAL SERVICE MANUAL Rule #1 KILL THE AC POWER BEFORE IT KILLS YOU Under no circumstances should any person reach within the cabinets for the purpose of servicing or adjusting the equipment without first disconnecting the AC power or without the immediate presence of another person capable of rendering aid. The “buddy” system is encouraged for transmitter work. Rule #2 DO NOT TAMPER WITH INTERLOCKS OR SAFETY SHIELDS Under normal circumstances, no safety shield should be removed.
MXi030U TECHNICAL SERVICE MANUAL Avoid wearing loose clothing and personal jewelry such as rings, watches, and chains when working near energized circuits. Make a habit of removing all jewelry and storing it in a safe place as soon as you enter the transmitter building. Before beginning work, shut off all AC to the transmitter power supplies. Tag and lockout the switches.
MXi030U TECHNICAL SERVICE MANUAL 3 LARCAN PARTS, ASSEMBLIES, ASSEMBLY DRAWINGS AND SCHEMATIC NUMBERS 3.1 VENDOR STANDARD PART NUMBERS Vendor or original manufacturer part numbers are indicated for most components. 3.
MXi030U TECHNICAL SERVICE MANUAL 3.3 LEADED RESISTORS Generic carbon composition resistors with leads are numbered as follows: nnnx 3R P - or - nnx Power Rating Resistance Value * 152 = 1/4W nn - 77 = 1/2W Tolerance first digits of K =10% resistance (5, 10% tol.) 78 = 1W nnn - 79 = 2W resistance (1% tol.) J =5% first digits of H =1% x - x10 multiplier For values between 1Ω and 10Ω, a letter “R” will appear in the resistance value to indicate the decimal place.
MXi030U TECHNICAL SERVICE MANUAL Example: 9C08052A1001FK (Size 0805, Power Rating 1/10W, Resistance 1kohm, Tolerance 1%, Temperature Coefficient 100ppm/°C) 3.5 SURFACE MOUNT CAPACITORS There is no specifically recommended supplier of these parts.
MXi030U TECHNICAL SERVICE MANUAL A revision letter or number may follow the model or group number marked on the nameplate, chassis, or circuit board; or on the parts list (where it is an "R" followed by a dash and a number). Whenever a revision letter or number appears, it should be quoted in any communication regarding the equipment.
MXi030U TECHNICAL SERVICE MANUAL 4 GLOSSARY The following glossary lists terms and abbreviations found in this and other LARCAN documentation.
MXi030U TECHNICAL SERVICE MANUAL CMOS J COMPLIMENTARY METAL OXIDE SEMICONDUCTOR CONN CONNECTOR K CONTACTOR (MAGNETICALLY OPERATED) S CONTACTOR (MANUALLY, MECHANICALLY, THERMALLY OPERATED) Y CW CONTINUOUS WAVE CTRL/CTL CLG CONTROL COOLING CORR CORRECTION CCW COUNTERCLOCKWISE CPLR COUPLER B/CPLR COUPLER BI-DIRECTIONAL D/CPLR COV COUPLER DIRECTIONAL COVER XTAL CRYSTAL DEFL DEFLECTOR DEMUX DELAY LINE DEMULTIPLEXER DET DETECTOR CR CURRENT REGULATOR DL DIFF DIFFERENTIAL DIG DI
MXi030U TECHNICAL SERVICE MANUAL FREQ FREQUENCY FDM FREQUENCY DIVISION MULTIPLEX FM FSK FREQUENCY MODULATION FREQUENCY SHIFT KEYING FR FRONT F FUSE X FUSEHOLDER G GENERATOR GROM GND GROMMET GROUND GRP DEL GROUP DELAY E HALL ELEMENT HDL HANDLE H J HR HARDWARE HDR HEADER HEATER HR HEATING RESISTOR HTSK HEATSINK HCMOS HIGH DENSITY CMOS HMOS HP HIGH PERFORMANCE MOS HIGH POWER HCT HIGH SPEED CMOS HV HIGH VOLTAGE HPS HIGHPASS FILTER HORIZ HORIZONTAL HSG HOUSING HYBRID CIRCUI
MXi030U TECHNICAL SERVICE MANUAL FL LP LOW POWER LV LOW VOLTAGE LWR LPS LOWER LOWPASS FILTER E MAGNETIC CORE Vcc MAIN POWER SUPPLY M MALE MPT MALE PIPI THREAD MATL MATERIAL MECHANICAL INTERLOCK MP MEDIUM POWER MP MP MECHANICAL PART MOS METAL OXIDE SEMICONDUCTOR MOSFET METAL OXIDE SEMICONDUCTOR FET MOV MTR METAL OXIDE VARISTOR METER M METER MK MICROPHONE E MISCELLANUS ELECTRICAL PART HY MXR MOD MIXER MODEL MOD MODULATION MODEM MODULATOR/DEMODULATOR MON MONITOR B U M
MXi030U TECHNICAL SERVICE MANUAL P PRIMARY PCA PRINTED CIRCUIT ASSEMBLY PCBOARD PCM PRINTED CIRCUIT BOARD PULSE CODE MODULATION Q QUADRATURE QAM QUADRATURE AMPLITUDE MODULATION RU RACK UNIT 1 3/4" RF RFIC RADIO FREQUENCY RADIO FREQUENCY INTEGRATED CIRCUIT Y J K QUARTZ RFI RADIO FREQUENCY INTERFERENCE RAM RANDOM ACCESS MEMORY ROM READ ONLY MEMORY RCVR RECEIVER RX RCPTL RECEIVING RECEPTACLE REF REFERENCE RFL REFLECTED REJ REJECT RL RLY REJECT LOAD RELAY K RELAY REM R REM
MXi030U TECHNICAL SERVICE MANUAL TEMP TEMPERATURE TERM TERMINAL TERMBLK TERMINAL (INDIVIDUAL) TERMINAL BLOCK E TB TERMINAL BLOCK RT TERMISTOR TC TERMOCOUPLE TP TEST POINT TP M X TEST POINT THERMOMETER TSSOP THIN SHRINK SMALL OUTLINE PACKAGE TSOP THIN SMALL OUTLINE PACKAGE XFMR TRANSFORMER T TRANSFORMER Q TTL TRANSISTOR TRANSISTOR TRANSISTOR LOGIC XLTR TRANSLATOR XMTD TRANSMITTED XMTR TRANSMITTER TX TRANSMITTER TRANSMITTER / TRANSMITTING TRIM TRIMMING TX UHF ULTRA HIGH FR
MXi030U TECHNICAL SERVICE MANUAL EBU EUROPEAN BRODCASTING UNION DVB EUROPEAN DIGITAL TV FCC GPIB FEDERAL COMMUNICATION COMMISSION GENERAL PURPOSE INTERFACE BUS GPS GEOGRAPHIC POSITIONING SYSTEM HP HEWLETT PACKARD HDTV HIGH DEFINITION TELEVISION HD HIGH DENSITY HTTP ICPM HYPERTEXT TRANSFER PROTOCOL INCIDENTAL CARRIER PHASE MODULATION INC INCORPORATED ISO INDUSTRIAL STANDARDS ORGANIZATION IEEE INSTITUTE OF ELECTRICAL AND ELECTRONIC ENGINEERS IEC INTERNATIONAL ELECTROTECHNICAL COMMISSION
MXi030U TECHNICAL SERVICE MANUAL TECHNICAL TERMS AD ANODE ATM ASYNCHRONOUS TRANSFER MODE BIN BINARY CAD COMPUTER AIDED DESIGN CAE DEC COMPUTER AIDED ENGINEERING DECIMAL HEX HEXADECIMAL IRQ INTERRUPT REQUEST OCT OCTAL VSB VESTIGIAL SIDEBAND MODULATION VM VOLTMETER UNITS OF MEASURE, MEASUREMENTS, ORDERS OF MAGNITUDE pico/ p nano/ n TSM20-378 Rev 0 July 18, 2007 1.00E-12 1.00E-09 micro/ u 1.00E-06 mili/ m 1.00E-03 kilo/ k 1.00E+03 Mega/ M 1.00E+06 Giga/ G Tera/ T 1.00E+09 1.
MXi030U TECHNICAL SERVICE MANUAL W WATT ACS ACCESS MISCELLANEOUS TSM20-378 Rev 0 July 18, 2007 BSC BASIC BLK BLACK BLU BRN BLUE BROWN CARR CARRIAGE CHNG CHANGE DCR DECORATIVE DEV DEVIATION DOS FAX DISK OPERATING SYSTEM FACSIMILE GRY GRAY GRN GREEN HEPA HIGH EFFICIENCY PARTICULATE AIR h JPEG HOUR JOINT PHOTOGRAPHIC EXPERTS GROUP MRI MAGNETIC RESONANCE IMAGINARY MAX MAXIMUM MIN MINIMUM MISC MISCELLANEOUS MOD ORN MODIFICATION ORANGE LBS POUNDS QUOT QUOTATION R READ
MXi HALF PALLET OPERATIONS AND MAINTENANCE CONTENTS 1 MXi AMPLIFIER..............................................................................................................................................................1 2 MXi CONTROLLER ........................................................................................................................................................2 3 AMPLIFIER INSTALLATION AND STARTUP .......................................................................
MXi HALF PALLET OPERATIONS AND MAINTENANCE FIGURE 13 BOTTOM VIEW OF MXI .............................................................................................................................................10 FIGURE 14 FAN ARRAY ..............................................................................................................................................................10 FIGURE 15 FAN ATTACHMENT TO MOUNTING PLATE ........................................................................
MXi HALF PALLET OPERATIONS AND MAINTENANCE 1 MXi AMPLIFIER The RF section of the MXi 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 MXi Amplifier Heatsink Assembly Also mounted on the heatsink is a thermal switch that protects the amplifier from over temperature conditions.
MXi HALF PALLET 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.
MXi HALF PALLET OPERATIONS AND MAINTENANCE Forward (FWD) and Reflected power (RFL), AURal power, AGC and CUTBack (VSWR) control voltage, as well as the heatsink TEMPerature (Optional) can be displayed by selecting the AMP submenu as shown in Figure 5. Figure 5 Amplifier (AMP) Submenu Pressing the power supply ‘P/S’ submenu from the Main Menu will display the power supply voltage and current consumption as well as its status.
MXi HALF PALLET 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.
MXi HALF PALLET OPERATIONS AND MAINTENANCE Figure 8 Main Menu 3.3 BEFORE TURNING THE AMPLIFIER ON From the Main Menu, the status of the amplifier is displayed and shows if the amplifier is ready for operation. Status legends, when lit, such as the INTK (INTERLCOK), usually signify OK conditions and that the transmitter is ready to be turned ON. Check that all of the following conditions are met: 1. EXCITER or Channel Processor is Ready.
MXi HALF PALLET OPERATIONS AND MAINTENANCE • Push the Front Panel ON/OFF button so that it is NOT pushed in. 3.4 AMPLIFIER ON SEQUENCE Upon depressing the ON button, the fans start and at the same time the +32V power supply is enabled, thus applying B+ to the MXi Amplifier. Since the Exciter or Channel Processor is on hot standby (RF is always applied), the amplifier normally produces output power immediately. 3.4.1 Turning ON MXi Amplifier 10.
MXi HALF PALLET 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 +32V (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.
MXi HALF PALLET OPERATIONS AND MAINTENANCE • • Apply +28V to the B+ terminal. Monitor the current and adjust R12 counter clockwise (CCW) for a total current of about 2.5A + 0.1A. • 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 2.5A, the gain in the range of 470MHz to 860 MHz should be 15 to 16dB. 4.
MXi HALF PALLET 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.
MXi HALF PALLET OPERATIONS AND MAINTENANCE 6 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. 6.1 REMOVING THE FAN ARRAY The MXi fan array consists of four 4” muffin-type fans which are attached to the mounting plate.
MXi HALF PALLET OPERATIONS AND MAINTENANCE 6.2 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 6.1. 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 five mounting screws. Note: Screws only need to be snug; do not overtighten. 6.
MXi HALF PALLET OPERATIONS AND MAINTENANCE 7 TEST EQUIPMENT SETUP Figure 15 Test Equipment Setup PUB07-03 Rev 1 July 17, 2007 07-03-12 MXi Half Pallet Operations and Maintenance
MXi HALF PALLET OPERATIONS AND MAINTENANCE 8 SPECIFICATIONS Specifications are subject to change without notice. 8.1 ELECTRICAL AC Line Input .....................................................................................................................90 to 264VAC, 50 to 60Hz Power Consumption ............................................................................................................................ 260VA (typical) 8.2 ENVIRONMENTAL Ambient Temperature ..........................
MXi HALF PALLET AMPLIFIER CHASSIS CONTENTS 1 MXi HALF PALLET AMPLIFIER.................................................................................................................................1 FIGURES FIGURE 1 FRONT VIEW OF MXI AMPLIFIER ..................................................................................................................................1 FIGURE 2 REAR VIEW OF MXI AMPLIFIER ...............................................................................................
MXi HALF PALLET AMPLIFIER CHASSIS 1 MXi HALF PALLET AMPLIFIER The MXi Amplifier Chassis Assembly 41D2047G2 consists of a standard 19" rack mountable 5.25" (3RU) enclosure containing the amplifier heatsink assembly, a fan array assembly consisting of four DC cooling fans, a controller board with built-in RF detectors, and a front panel consisting of ON/OFF, RESET switches and an LCD/Touchpad, and a rear panel assembly with connectors for interfacing to external equipment.
MXi HALF PALLET AMPLIFIER CHASSIS The heatsink cooling fans are the +12DC, 4" muffin model. Typically, they come ON at the same time B+ is applied to the power amplifier. It is connected to the controller PC board connector, J8. As built, the cooling fans push air from the front panel through the heatsink and through the perforations in the rear panel. This assembly is located underneath the MXi Controller board.
MXi 500W POWER SUPPLY CONTENTS 1 MXi 500W POWER SUPPLY LAR500-32-P5337..........................................................................................................1 2 POWER SUPPLY MANUAL REPRINT ........................................................................................................................3 FIGURES FIGURE 1 MXI 500W POWER SUPPLY ..........................................................................................................................................
MXi 500W POWER SUPPLY 1 MXi 500W POWER SUPPLY LAR500-32-P5337 The LAR500-32-P337 power supply used in the MXi single pallet amplifier is a free-standing, power factor corrected 500W unit. It has the capability to deliver up to 15 Amps when the power supply output is set to +32VDC. The design of this unit results in a highly efficient power supply ideal for the MXi power level.
MXi 500W POWER SUPPLY 8. NOT USED 9. NOT USED 10. GND AC GND 11. N AC Neutral 12.
MXi 500W POWER SUPPLY 2 POWER SUPPLY MANUAL REPRINT The following pages are a reprint of the operating manual of LAR500-32-P337 switching power supply, with permission from Absopulse Electronics Ltd.
MXi 500W POWER SUPPLY PUB05-67 Rev 1 July 17, 2007 05-67-4 MXi 500W Power Supply
MXi 500W POWER SUPPLY PUB05-67 Rev 1 July 17, 2007 05-67-5 MXi 500W Power Supply
MXi 500W POWER SUPPLY PUB05-67 Rev 1 July 17, 2007 05-67-6 MXi 500W Power Supply
MXi AMPLIFIER CONTROLLER BOARD REV.2 CONTENTS 1 INTRODUCTION .............................................................................................................................................................1 2 GENERAL OPERATIONS ..............................................................................................................................................3 2.1 CONNECTOR AND SIGNAL DEFINITIONS ......................................................................................
MXi AMPLIFIER CONTROLLER BOARD REV.2 3.2.7 FAN2..................................................................................................................................................................18 3.2.8 FAN3..................................................................................................................................................................18 3.3 POWER SUPPLY SCREEN .....................................................................................................
MXi AMPLIFIER CONTROLLER BOARD REV.2 7.1 7.2 7.3 ADDENDUM 1– CDS51405 DISPLAY CONTROLLER ....................................................................................................46 ADDENDUM 2–DUAL DIGITAL POTENTIOMETER WITH EEPROM .............................................................................49 ADDENDUM 3–SPI/MICROWIRE-COMPATIBLE UART AND +/-15KV ESD-PROTECTED RS-232 TRANSCEIVERS WITH INTERNAL CAPACITORS .............................................................................
MXi AMPLIFIER CONTROLLER BOARD REV.2 1 INTRODUCTION This manual describes revision 2.0 or higher of the circuit board. 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.
MXi AMPLIFIER CONTROLLER BOARD REV.2 Figure 3 Main Menu Screen Forward (FWD) and Reflected power (RFL), AURal power, AGC and CUTBack (VSWR) control voltage, as well as the heatsink TEMPerature (Optional) can be displayed by selecting the AMP submenu as shown in Figure 4. Figure 4 Amplifier (AMP) Submenu Pressing the power supply P/S submenu from the Main Menu will display the power supply voltage and current consumption as well as its status.
MXi AMPLIFIER CONTROLLER BOARD REV.2 2 GENERAL OPERATIONS 2.1 CONNECTOR AND SIGNAL DEFINITIONS The connectors on the MXi control board are all shown in Figure 26, which is sheet #3 of the Schematic. The individual signals that are associated with each pin of the connector are also given. A brief description of each of the connectors on the board follows. 2.1.1 J1 BDM (Background Debug Mode) Connection This is used by the software developer to debug the software programmed into the HC08 CPU.
MXi AMPLIFIER CONTROLLER BOARD REV.2 2.1.7 J7 Transmitter Switch Interface This uses a nine-wire ribbon cable to send status/telemetry and receive commands from the rear panel nine-pin D-shell connector. Although J7 has 10 pins, only the first nine are actually used with pin 10 being left open. This ribbon cable may not be installed if there is only a single transmitter system or if there is no transmitter switching unit included in the RF system. 2.1.
MXi AMPLIFIER CONTROLLER BOARD REV.2 2.2.1.2. Jumper E1–Debug/Normal Mode This jumper allows factory programming and debug of the HC08 microcontroller. This should always be in the Normal position for proper operation in the field. 2.2.1.3. Jumper E2–Remote Control Reset This jumper allows the operator to use the remote Reset command to effect a reset of the HC08 microcontroller.
MXi AMPLIFIER CONTROLLER BOARD REV.2 2.2.1.10. Jumper E9–Forward RF Detector Color Burst Trap When installed, this jumper enables the filter that removes the color burst from the RF signal. This would only be installed on the analog transmitters, as the digital amplifier does not have a color burst. 2.2.1.11. Jumper E10–Forward RF Detector Sound Carrier Trap When installed, this jumper enables the filter that removes the sound carrier from the RF signal.
MXi AMPLIFIER CONTROLLER BOARD REV.2 2.2.1.20. Jumper E19– Peak or Sync Detection This jumper allows the forward power sample to be either a Peak detection or Back Porch detection using the visual sync. The optional Aural detection piggyback board must be installed to provide the sync detection facility. For most applications (including all of the digital modulation standards), jumper E19 would be set for peak (Pk) since there is no vertical sync interval that can be locked onto for these signals.
MXi AMPLIFIER CONTROLLER BOARD REV.2 that a VSWR trip/Lockout does not change the ON/OFF state of the transmitter, it just opens an interlock to shut it down. The LED beside this pushbutton shows the state of the VSWR relay K2. When there is a VSWR trip, the MXi controller resets it automatically until three trips occur in a one minute span. When a VSWR trip occurs, this LED momentarily flashes, indicating that a trip did occur but the CPU has reset the trip.
MXi AMPLIFIER CONTROLLER BOARD REV.
MXi AMPLIFIER CONTROLLER BOARD REV.2 Note the AGC voltage from the LCD, if it is near to a value of 0 (i.e., under 0.1V), then there is no AGC action left and the power cannot be raised any further. If the amplifier power is under 100%, then check the RFL power level and CUTBACK voltage to verify that the amplifier is not reducing power to protect from a VSWR condition. The cutback circuit checks the level of reflected power as displayed on the LCD screen above [RFL=00.1%].
MXi AMPLIFIER CONTROLLER BOARD REV.2 2.6.2 Soft Interlocks There are parameters that the CPU monitors and if they indicate an error condition, the CPU will issue and OFF command to the ON/OFF relay and set the appropriate error flag. Note: if the Local or Remote ON/OFF commands are jumpered to the Override state, the CPU will be unable to shut off the amplifier via K2. For this reason it is recommended that the ON/OFF controls are left jumpered in the normal positions unless an emergency condition exists.
MXi AMPLIFIER CONTROLLER BOARD REV.2 2.7.2 Remote Controls (Individual) Connector J6 provides for individual lines of control/status/telemetry that would normally be connected to an external vendor remote control system (such as Moseley or Gentner). This 16-pin connector would usually have a 15-wire ribbon cable attached that would route the signals from the first 15 pins of J6 to a 15-pin D-shell connector Jxx on the rear panel. The details of the signals on this connector are given in Section 5. 2.7.
MXi AMPLIFIER CONTROLLER BOARD REV.2 3 LCD GUI INTERFACE AND TOUCHPAD The user interface to the transmitter is mainly accomplished with the front panel LCD that incorporates a touchpad as an integral part of the unit. The touchpad consists of a thin membrane attached to the LCD surface which implements a software-driven menu selection system. The LCD has the capability of displaying a number of different screens, which are selected by the operator via the touchpad.
MXi AMPLIFIER CONTROLLER BOARD REV.2 reference for the current transmitter power (not the bar graph). This display has a maximum value of 169% power when the transmitter detectors are set up for a DC output of 4.0 at full power. This value is derived from the fact that the detector can output a maximum of 5.0VDC to the telemetry circuits, which translates to an output power of 169%.
MXi AMPLIFIER CONTROLLER BOARD REV.2 • Not Lit when there are no current Log entries 3.1.5 AMP Status that indicates the RF amplifier is currently active and is operating properly. • Lit when the amplifier is ON, forward power is OK and reflected power is low. • Not Lit when the amplifier is either OFF or has some operational problems. If the amplifier has indeed been set to ON and the front panel ON LED is lit then an error is present.
MXi AMPLIFIER CONTROLLER BOARD REV.2 Figure 9 Amps Submenu The first line shows the three possible RF powers. The first item is the forward power denoted as FWD that represents the total output RF power from the amplifier and would be the same value that is displayed on the Main LCD menu. This is represented as a percentage of the full rated output power of the transmitter. The second item on the first line is the reflected power from the amplifier.
MXi AMPLIFIER CONTROLLER BOARD REV.2 3.2.1 TRIP VSWR Trip Status • Lit when the system has seen at least one VSWR trip, can be reset by operator using LCD touchpad. • Not lit when there have been no VSWR trips since the last time this was cleared. Note that this does not mean that there is a current VSWR trip but that one did occur. The operator may have this status as true (with no Lockout status) and still have the RF amplifier active. 3.2.
MXi AMPLIFIER CONTROLLER BOARD REV.2 3.2.7 FAN2 Status that shows if FAN2 is currently operational. When the transmitter is turned ON, all the fans are turned on. • Lit when fan rotational status is true, this only happens if the fan is actually rotating. • Not lit when the fan is not rotating; if the other fans are OK, this indicates a failure. 3.2.8 FAN3 Status that shows if FAN3 is currently operational. When the transmitter is turned ON, all the fans are turned on.
MXi AMPLIFIER CONTROLLER BOARD REV.2 normally), OFF NORMAL (turned off by operator) or OFF TRIPPED (off due to an error). Note: if the power supply is OFF, there will be no voltage or current telemetries. The third line has four status lights that will tell the operator which element has caused the power supply to shut off. 3.3.1 OK STAT Power Supply OK status, the 32V power supply generates this internal status that all is OK. • Lit when the Power Supply is ON.
MXi AMPLIFIER CONTROLLER BOARD REV.2 needed and the fan interlock status would then normally be OFF. This makes it important to indicate to the operator the intended state of the transmitter as either ON or OFF to correctly interpret the subsequent status.
MXi AMPLIFIER CONTROLLER BOARD REV.2 The operator may have this status as true (with no Lockout status) and still have the RF amplifier active. This can be reset by the operator using the LCD touchpad button RST or by the front panel Reset button. 3.4.2 L/O VSWR Lockout Status • Lit when there is no VSWR Lockout condition. • Not lit when the system has seen three VSWR trips in under 1 minute. When a VSWR trip occurs, the MXi controller will reset the trip automatically and repower the RF amp.
MXi AMPLIFIER CONTROLLER BOARD REV.2 • Lit when fan rotational status are all true, this only happens if the fan is actually rotating. • Not lit when at least one fan is not rotating. The bottom line represents the menu selection buttons with a possible option of eight different submenu selections. The operator just needs to press the touchpad (lightly) either on or just above the desired menu select button. The first button is the RST button that clears any VSWR trips or Lockouts when pressed.
MXi AMPLIFIER CONTROLLER BOARD REV.2 from the individual J6 commands are not counted. The operator can uses this information along with the CNT value from line #1 of the LCD to determine the source of the remote command. If the CNT increments but the RCNT does not, then the recent remote command came from J6. If both the CNT and the RCNT increment, then the recent remote command came from the RS232 stream.
MXi AMPLIFIER CONTROLLER BOARD REV.2 3.5.5 Error Serial Input Stream Error The external computer will send a four-byte serial stream of a specific format to ask for a certain action to be taken. The MXi monitors the format of this four-byte serial stream and sets the Error status if the stream has the wrong format. This is useful in determining if there is a serial transmission problem between the external computer and the MXi. This bit can be cleared by the CLR menu button on the LCD.
MXi AMPLIFIER CONTROLLER BOARD REV.2 Figure 15 Logs Submenu Screen The logs are displayed up to three at a time, in the order in which they were detected in the controller. That is, the logs are in chronological order from the time they were received. The seventh menu button on the fourth line of the LCD shows the total number of log entries [our example shows 2 entries #=02]. A maximum of 99 log entries can be held in the log table.
MXi AMPLIFIER CONTROLLER BOARD REV.2 Figure 16 General Submenu Screen The eighth menu button is labeled OUT and will cause the LCD screen to return to the Main Menu. PUB06-82 Rev 1 July 17, 2007 06-82-26 MXi Amplifier Controller Board Rev.
MXi AMPLIFIER CONTROLLER BOARD REV.2 4 SETUP PROCEDURES The following sections detail the various set up procedures for the MXi transmitter system. These procedures should only be done by qualified personnel. If the calibrations and setups are done improperly, it can result in the transmitter being prone to damage. The transmitter is normally set up in the factory for the particular operating power required when first installed.
MXi AMPLIFIER CONTROLLER BOARD REV.2 For Digital service, the above four jumpers would not be installed. If the desired transmitter output power is the same as what the transmitter was originally set up for at the factory, there should be no need to change the gain jumpers on the RF detectors.
MXi AMPLIFIER CONTROLLER BOARD REV.2 At this point, the operator should proceed to verify cutback and VSWR trip functions, as described in the next two sections. 4.2 AGC AND CUTBACK PROTECTION Before the operator attempts to set up the AGC or cutback circuitry, the forward and reflected power levels must be properly set up to calibrated levels as described in Section 4.1. 4.2.1 AGC Setup The AGC is simply set up using the Amps submenu that is accessed from the Main menu of the LCD.
MXi AMPLIFIER CONTROLLER BOARD REV.2 To check the VSWR trips, a power sample must be fed into the reflected power connector of the MXi board that is –10dB down from the forward power sample level. The most convenient way to accomplish this is to take this sample from the RF monitor port on the rear of the transmitter chassis. 1. Disconnect the AGC control connector J10 from the MXi board to remove any possible AGC or cutback action while verifying the Reflected power.
MXi AMPLIFIER CONTROLLER BOARD REV.2 screen is the new baud that is not yet programmed. Note: The MXi will still operate at the original baud until the new one is saved. If the user presses the STOP menu button, then the number of stop bits in the serial format will toggle between 1and 2. The new desired number of stop bits will be displayed in the second line of the LCD within the 8B-1S-NoP section where the stop bits will be either 1S or 2S in this string.
MXi AMPLIFIER CONTROLLER BOARD REV.2 5 REMOTE CONTROL CONNECTIONS MXi TRANSMITTER On the rear of the transmitter Chassis, the remote control connections are available on a 15-pin male D-shell connector J6. This includes all of the remote controls, status and telemetries available to the operator. These remote signals are routed from the MXi Control board via a 15-wire ribbon cable from connector J6 of the MXi Control board.
MXi AMPLIFIER CONTROLLER BOARD REV.2 TX D-Connector PC Board Connector Designation Description Pin 1 J6 Pin 1 RC_TX_On Turns Transmitter ON Pin 9 J6 Pin 2 RC_TX_Off Turns Transmitter OFF Pin 2 J6 Pin 3 RC_Reset Resets VSWR Trip Pin 4 J6 Pin 7 RC_VOR VOR On Controls Pin 12 J6 Pin 8 Ground Ground Reference Pin 15 J6 Pin 14 EXT1+ Secondary Ext1 Intk Pin 8 J6 Pin 15 EXT1– Secondary Ext1 Intk Remote Control 5.1.
MXi AMPLIFIER CONTROLLER BOARD REV.2 5.1.3 RC_TX_VOR Remote Transmitter VOR Control The following discussion is assuming that jumper E5 is in the EXT position and jumper E7 is not installed. The VOR (Video Operated Relay) control is a specialize input that performs a very rudimentary control of a network of transmitters. The VOR is a signal that is active when video has been present for a specified length of time, typically around 30 seconds or longer.
MXi AMPLIFIER CONTROLLER BOARD REV.2 5.2.1 Status Outputs Figure 22 Status Outputs These are current sinking open collector outputs, out of quad pack MPQ2222 (2N2222A) NPN transistors driven by opto-isolator devices. The available output sink current is dependent on the gain of the NPN and the optoisolator transfer ratio. Generally, one can expect at least 100mA of sinking current for each output listed here.
MXi AMPLIFIER CONTROLLER BOARD REV.2 TX D-Connector PC Board Connector Designation Description Pin 5 J6 Pin 9 RT_FWD Forward RF power level Pin 13 J6 Pin 10 RT_RFL Reflected RF power level Pin 6 J6 Pin 11 RT_AUR Aural RF power level (optional) Pin 15 J6 Pin 12 RT_AGC AGC voltage (1/2 scale) Pin 7 J6 Pin 13 RT_CUTB Cutback voltage (1/2 scale) Pin 12 J6 Pin 8 Ground Ground Reference Remote Controls PUB06-82 Rev 1 July 17, 2007 06-82-36 MXi Amplifier Controller Board Rev.
MXi AMPLIFIER CONTROLLER BOARD REV.2 6 CIRCUIT DESCRIPTIONS 6.1 MC68HC908 MICROPROCESSOR The Motorola MC68HC908GT microprocessor (often referred to as the CPU or HC08) performs all of the control interface and communications in the MXi transmitter system. It is a 44-pin surface mount PLCC type device that is permanently soldered to the circuit board and is not field serviceable or easily replaced without special surface mount tooling.
MXi AMPLIFIER CONTROLLER BOARD REV.
MXi AMPLIFIER CONTROLLER BOARD REV.2 The MXi board has a built-in Hall Effect current sensor that is able to measure the current drawn by the RF amplifier from the +32 volt power supply. The standard MXi low power transmitter would have a 25 amp current sensor. There are two possible sensors that could be installed in the MXi which depend on the actual current level that is to be measured. A higher power MXi transmitter would be fitted with a 40 amp current sensor.
MXi AMPLIFIER CONTROLLER BOARD REV.2 6.3 ON/OFF RELAY K1 The ON/OFF relay K1 and associated circuitry is shown in Figure 25. Relay K1 is a four-pole, single-side stable relay that requires a constant voltage applied to its coil to maintain contact closure. The contacts of this relay provide the control signals to activate the +32V power supply and the cooling fans. There are two elements that determine if power is applied to the coil of K1.
MXi AMPLIFIER CONTROLLER BOARD REV.2 The reflected power sample is send to OpAmp U17C which compares this with the reference level set by potentiometer R15 and test point TP6. This reference level is set up by sending –16dB of the transmitter forward power into the reflected port and adjusting R105 until the MXi begins to just start reducing the transmitters output power.
MXi AMPLIFIER CONTROLLER BOARD REV.2 The UART has its own 1.8432MHz crystal to generate the appropriate bauds. The CPU program sets up the baud as 9600 as the default but this can be altered by user command via the LCD touchpad menus. An interrupt line is provided by the UART to signal the HC08 CPU when it is available for more data to transmit or when new data has been received. The device can also interrupt the HC08 in the presence of certain types of serial transmission error conditions.
MXi AMPLIFIER CONTROLLER BOARD REV.2 Finally, Q4 serves as a low impedance video source. Jumper E9 is used to introduce color subcarrier trap FL1. An alternate trap consisting of C43, C25 and L1 (marked with asterisks) can also provide this function. The alternate trap can also be easily changed in values to provide different frequency traps for other systems (like PAL). Note: only one of either FL1 or the Inductor/Capacitor traps would be installed but never both.
MXi AMPLIFIER CONTROLLER BOARD REV.2 Because a single supply op-amp is used at U14D, the output seen on TP4 will contain a small DC offset which must be minimized because low level signals are near ground/earth potential. With no RF input, this offset voltage is adjusted by potentiometer R80 as near as possible to ground/earth. The setting can be seen when using a DC-coupled scope. Adjust R80 to move the DC level toward ground/earth potential; stop turning the potentiometer immediately the DC ceases moving.
