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Nautel NX50 Troubleshooting Manual

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NX50 Transmitter
Troubleshooting Manual
Document:NHB-NX50-TRB
Issue:
6.0 2019-04-01
Status:
Standard

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  • Page 1 NX50 Transmitter Troubleshooting Manual Document:NHB-NX50-TRB Issue: 6.0 2019-04-01 Status: Standard...
  • Page 3 The comparisons and other information provided in this document have been prepared in good faith based on publicly available information. The reader is encouraged to consult the respective manufacturer's most recent published data for verification. © Copyright 2019 NAUTEL. All rights reserved.

  • Page 5: Table Of Contents

    NX50 Troubleshooting Manual Table of contents Contents Release control record Responding to alarms Corrective maintenance Electrostatic protection Identifying an alarm Troubleshooting an alarm Accessing the Inside of the Transmitter 1-42 Troubleshooting Tips 1-43 Removing and reinstalling RF power modules 1-51...
  • Page 6 NX50 Troubleshooting Manual RF Voltage Probe Replacement 1-93 RF Current Probe Replacement 1-95 Parts Lists Parts information Family tree How to locate information about a specific part Column content Common abbreviations/acronyms Wiring/connector lists Wiring lists provided Wiring lists not provided...
  • Page 7 NX50 Troubleshooting Manual Mechanical Drawings Identifying mechanical drawings Content of mechanical drawings List of terms Issue 6.0 2019-04-01 Page vii...
  • Page 8 NX50 Troubleshooting Manual Page viii Issue 6.0 2019-04-01...

  • Page 9: Release Control Record

    NX50 Troubleshooting Manual Release control record Issue Date Reason 2019-04-01 Supports release 6 of hardware (NARA53E) and software version NX SW 4.7 or higher. Issue 6.0 2019-04-01 Page ix...
  • Page 10 NX50 Troubleshooting Manual Page x Issue 6.0 2019-04-01...

  • Page 11: Responding To Alarms

    NX50 Troubleshooting Manual Responding to alarms Section 1: Responding to alarms This section provides instructions you need when performing troubleshooting on the NX50 transmitter. This section includes the following topics: • Corrective maintenance • Electrostatic protection - see page 1-3 •...
  • Page 12 NX50 Troubleshooting Manual Responding to alarms On-air troubleshooting On-air troubleshooting can be performed from a remote location, or locally at the transmitter site. Remote troubleshooting Remote on-air troubleshooting consists of monitoring the transmitter's radiated signal using an on-air monitor or via a LAN connection, and observing the status of each remote fault alarm indicator.
  • Page 13 NX50 Troubleshooting Manual Responding to alarms It is recommended that the transmitter’s output be connected to a precision 50  resistive dummy load (rated for 1.5 times the rated transmitter carrier power) before starting off-air troubleshooting procedures. If an appropriate dummy load is not available, troubleshooting for a majority of faults can be performed with the RF power stage turned off.
  • Page 14 NX50 Troubleshooting Manual Responding to alarms Stress current protection Every precaution should be taken to ensure the static sensitive semiconductor devices are protected from unnecessary stress current. This is achieved by ensuring that current is not flowing when an electrical connection is broken, and that voltages are not present on external control/monitoring circuits when they are connected.

  • Page 15: Identifying An Alarm

    NX50 Troubleshooting Manual Responding to alarms Identifying an alarm You can identify an alarm by viewing the Transmitter Status page (Figure 1.1), either locally on the front panel of the transmitter, or remotely through an ethernet connection. After successfully identifying an alarm, attempt to determine the cause of the alarm and correct it (see “Troubleshooting an alarm”...
  • Page 16 NX50 Troubleshooting Manual Responding to alarms Click the Status button to view the Transmitter Status page (Figure 1.1 on page 1-5), which displays a list of active alarms. Alarms are listed by their origin (Device column), then by name (Alarm column), and then by severity (Level column).

  • Page 17: Troubleshooting An Alarm

    4. If troubleshooting and subsequent replacement of a suspect PWB or module causes the alarm to disappear, the alarm has been successfully cleared. If the fault condition does not clear contact Nautel Customer Service for assistance. Issue 6.0 2019-04-01 Page 1-7...
  • Page 18 NX50 Troubleshooting Manual Responding to alarms Table 1.1: Troubleshooting Alarms Alarm (with Prefix) Description and Troubleshooting Action Controller: Audio Loss This alarm occurs if the modulation level is below the preset Shutdown threshold for the designated period of time set in the Audio Loss settings of the current preset, and the desired action was set to RF Inhibit.

  • Page 19: Control/Interface Pwb Replacement

    NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Controller: Controller This alarm is only visible in the transmitter logs, and indicates the Reset controller was reset because its +5 V power supply voltage was less than 1.4 V, which normally happens due to a loss of ac power.
  • Page 20 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Controller: EEPROM This alarm occurs when the transmitter is unable to read its Failure: Thresholds configuration for transmitter type and rack interface serial numbers from EEPROM upon boot-up. The transmitter will revert to its initial default settings, which may be different from the values set before the transmitter was shipped.

  • Page 21: Digital Am Exciter Pwb Replacement

    NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Controller: Exciter A (or This alarm occurs when the controller is configured to expect B) Not Responding exciter A (or B) is installed, and it has failed to receive any serial response from that exciter.
  • Page 22 PWB is not damaged. If not, verify the Fast SWR Shutback threshold is set properly (contact Nautel to obtain the correct setting for your transmitter). If this threshold is set...

  • Page 23: Gps Sync Pwb Replacement

    NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Controller: GPS Not This alarm indicates the transmitter is configured to use a GPS Responding sync PWB as a frequency and phase reference, but the controller is not receiving communication from the GPS sync PWB. The...
  • Page 24 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Controller: High RF This alarm indicates the controller's RF Drive Duty Cycle meter Drive has risen above 60% for longer than 10 seconds. This alarm will cause an exciter changeover, if automatic changeover is enabled and the transmitter is operating on the main exciter.
  • Page 25 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Controller: Internal This alarm will only be seen in transmitter logs, and indicates that Watchdog Reset the controller was reset by its internal watchdog. If this alarm persists, replace the control/interface PWB (see “Control/interface...
  • Page 26 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Controller: Low RF Drive This alarm indicates the controller's RF Drive Duty Cycle meter has fallen below 40% for longer than 10 seconds. This alarm will cause an exciter changeover, if automatic changeover is enabled and the transmitter is operating on the main exciter.
  • Page 27 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Controller: Rack 1 Not This alarm indicates that the controller is no longer receiving serial Responding communication from Rack 1. No action is taken. Check the wiring and connections between the control/interface PWB and the rack interface PWB and verify there is no damage.
  • Page 28 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Exciter A/B: Audio Loss This alarm occurs as a result of the modulation being below the specified threshold for the designated period of time set in the remote AUI’s Audio Loss tab for the current preset.
  • Page 29 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Exciter A/B: Cutback The forward power has been reduced due to multiple shutbacks. “ Cutback:” on page 1-12 of the Operations & Maintenance Manual for a description of the cutback routine. Check for associated alarms and refer to their troubleshooting information to determine the specific cause of the cutback.
  • Page 30 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Exciter A/B: High B+ This alarm indicates that the B+ voltage measured by the exciter Voltage exceeded the B+ setpoint by more than 20 V for at least ten (10) seconds.
  • Page 31 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Exciter A/B: High This alarm indicates either the average temperature of the 10 Temperature Foldback hottest power modules in the transmitter has exceeded 80 degrees Celsius, or the rectifier heatsink temperature has...
  • Page 32 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Exciter A/B: No B+ This alarm indicates the exciter’s B+ voltage sample is below 40 V Sample for more than 10 seconds. If there is an associated Low B+ voltage alarm, follow the troubleshooting information for that alarm.
  • Page 33 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Exciter A/B: No IBOC This alarm indicates there is no modulation data being provided Data by the embedded Exgine when the transmitter is running in an IBOC mode of operation. This alarm will trigger the Digital Input Loss alarm.
  • Page 34 If the operating frequency has been changed inadvertently, change the frequency back to its original setting. If a frequency change has been performed, recalibrate the exciter per the Nautel provided frequency change procedure. Exciter A/B: SWR...
  • Page 35 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Exciter A/B: SWR This alarm indicates the transmitter’s peak reflected power has Shutback exceeded the factory set peak reflected limit. This alarm causes the transmitter to immediately shut down its RF output, then recover.

  • Page 36: Exgine Pwb Replacement

    NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Exgine: AM/FM Mode This alarm indicates the Exporter mode does not match the Mismatched Exgine mode. Reconfigure the Exporter or Exgine to the correct mode. Exgine: DPLL Unlocked...
  • Page 37 Exgine: System Error This alarm acts as a summary alarm for a number of unexpected Exgine system conditions, such as failed memory checks or internal configuration errors. Contact Nautel Customer Service to troubleshoot this issue. Module: +15V Fail This alarm indicates the RF power module’s +15 V power supply is below +13.5 V or above +16.5 V.
  • Page 38 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Module #: High DC This alarm indicates that the RF power module's DC Current Current meter has exceeded 22 A, or the RF power module's peak DC current has exceeded the threshold applied to the microcontroller's comparator.
  • Page 39 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Module #: Invalid This alarm indicates there is a problem with the associated RF Thermistor Sample power module's temperature sample. When this alarm occurs, the associated RF power module will disable itself until the condition is cleared.
  • Page 40 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Module #: Low RF Drive This alarm indicates the RF drive duty cycle of the affected RF power module is below 35%. The affected RF power module is immediately disabled.

  • Page 41: Rack Interface Pwb Replacement

    NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Module #: RF Drive Fault This alarm indicates that the duty cycle of the RF drive or the dead time between RF drive signals on the associated RF power module is not as expected.
  • Page 42 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Rack #: High AC Voltage This alarm indicates the rack interface’s Ac Sample meter is above 384 V. The alarm clears when the sample falls below this voltage.
  • Page 43 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Rack #: High Rectifier This alarm indicates that the rectifier heatsink temperature has Temperature exceeded 100 degrees Celsius. The exciter should reduce the transmitter’s output power before this alarm occurs (see “Exciter: High Temperature Foldback”...
  • Page 44 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Rack #: Power Module # This alarm indicates that the rack interface PWB is not receiving a Not Responding response from the associated RF power module. Try swapping the affected RF power module with an RF power module in another location.
  • Page 45 NX50 Troubleshooting Manual Responding to alarms Alarm (with Prefix) Description and Troubleshooting Action Rack #: +30 V A (or B) This alarm occurs if the associated 30 V power supply’s output Fail voltage is outside its acceptable range of 25 V to 35 V. Suspect a faulty dc-dc converter on the rack interface PWB.
  • Page 46 NX50 Troubleshooting Manual Responding to alarms Table 1.2: Troubleshooting Summary Alarms Summary Alarm Name, AUI (front Description and Triggering Alarms panel UI) Audio Loss Summary This summary alarm is triggered if any of the following audio loss related alarms (Audio Loss Summary)
  • Page 47 NX50 Troubleshooting Manual Responding to alarms Table 1.2: Troubleshooting Summary Alarms Summary Alarm Name, AUI (front Description and Triggering Alarms panel UI) External Fault This summary alarm is triggered if any of the following external alarms occur: Summary (External Summary)
  • Page 48 NX50 Troubleshooting Manual Responding to alarms Table 1.2: Troubleshooting Summary Alarms Summary Alarm Name, AUI (front Description and Triggering Alarms panel UI) Maintenance Fault This summary alarm is triggered if any of the following maintenance related Summary alarms occur: (Maintenance...
  • Page 49 NX50 Troubleshooting Manual Responding to alarms Table 1.2: Troubleshooting Summary Alarms Summary Alarm Name, AUI (front Description and Triggering Alarms panel UI) Off Air Summary This summary alarm is triggered if any of the following off-air related alarms (Off Air Summary)
  • Page 50 NX50 Troubleshooting Manual Responding to alarms Table 1.2: Troubleshooting Summary Alarms Summary Alarm Name, AUI (front Description and Triggering Alarms panel UI) Power Supply Fault This summary alarm is triggered if any of the following power supply related Summary alarms occur:...
  • Page 51 NX50 Troubleshooting Manual Responding to alarms Table 1.3: Module Replacement Procedures Module Replacement Procedure RF Power Module page 1-51 Power Amplifier MOSFET page 1-60 Modulator MOSFET or Free-Wheel Diode page 1-62 Control/Interface PWB page 1-64 Remote Interface PWB page 1-66...
  • Page 52 OF PERSONNEL. Rear Access The rear of the NX50 has a lockable hinged door for safety purposes. Opening the door allows access to the power transformer (T1), Rectifier Assembly (A48), Rack Interface PWB (A6), RF Combiner Backplane PWB’s (A1 - A5), RF Voltage and Current Sample PWB (A41 & A42), Arc Detector assembly (A47), +15 V power supply (U3 &...
  • Page 53 NX50 Troubleshooting Manual Responding to alarms Troubleshooting Tips Controller: External PDM Inhibit A Controller: External PDM Inhibit alarm indicates that an external PDM inhibit command is present. The alarm could be caused by an short circuit in the external wiring path to the control/interface PWB or a fault in the switching circuitry on the control/interface PWB.
  • Page 54 NX50 Troubleshooting Manual Responding to alarms Controller: Interlock Open A Controller: Interlock Open alarm indicates an external interlock is open. The transmitter’s RF output will be inhibited. The external interlock input is wired to the control/interface PWB by the end user and triggered by the conditions that they set (e.g., the state of the door to the transmitter room).
  • Page 55 NX50 Troubleshooting Manual Responding to alarms RF Power Module faults There are many alarms on the AUI, prefixed by the text Module , that indicate faults related to one or more of the 20 RF power modules in a cabinet. The number that appears after Module or PM, identifies the serial identification of the affected RF power module.
  • Page 56 NX50 Troubleshooting Manual Responding to alarms Figure 1.3: RF Module Status Screen (all modules) Figure 1.4: RF Module Status Screen (individual module) Page 1-46 Issue 6.0 2019-04-01...
  • Page 57 NX50 Troubleshooting Manual Responding to alarms RF power module fault validation Each RF power module has a multi-colour LED on its front panel, which can help in identifying a fault and allowing you to determine whether remedial action is required now or later.
  • Page 58 A Rack #: Low B+ Voltage alarm is triggered when the B+ voltage is at least 25% below its expected level. Recovery from this alarm is automatic when the B+ voltage rises to an acceptable level. NOTE: An NX50 transmitter has only one rack (or cabinet) and will only display Rack 1. Page 1-48 Issue 6.0 2019-04-01...
  • Page 59 Recovery from this alarm is automatic when the ac voltage rises to an acceptable level. NOTE: An NX50 transmitter has only one rack (or cabinet) and will only display Rack 1. If the transmitter does not automatically recover from this alarm, the low ac voltage is normally caused by low ac mains voltage or improper primary taps on the power transformer.
  • Page 60 Manual. If necessary, turn off the transmitter, lock out the ac input voltage and retap the power transformer for the next lower voltage. 2. If the transformer taps are correct, the monitoring circuit is suspect. Contact Nautel for troubleshooting information.
  • Page 61 NX50 Troubleshooting Manual Responding to alarms Removing and reinstalling RF power modules Removing an RF power module 1. Confirm the location of the RF power module that is being removed. Note the alarm text includes a Module serial address that is also identified on the front panel of each RF power module.
  • Page 62 NOTE: To maintain proper airflow in the transmitter, install the dummy module assembly (Nautel part # 207-1038, located in the NX50 ancillary kit) if a replacement RF power module is not readily available after removing the defective module.
  • Page 63 AUI’s Upgrade Software page under the System Settings menu by running an upgrade using the existing .tgz file already installed on the transmitter. See the NX50 Operations and Maintenance Manual for detailed instructions Issue 6.0 2019-04-01 Page 1-53...
  • Page 64 NX50 Troubleshooting Manual Responding to alarms Figure 1.6: RF Power Module Locations RF Power Modules Front Door Removed for Clarity Page 1-54 Issue 6.0 2019-04-01...
  • Page 65 NX50 Troubleshooting Manual Responding to alarms Optimizing RF power module Performance When swapping damaged RF power modules with new RF power modules, it is possible that spurs of the fundamental PDM frequency (fc ± 155 kHz) may appear at the output of the transmitter.
  • Page 66 • A torque screwdriver with a torque range of 0.0 to 2.3 N-m (0 - 20 in.-lbs). Required for installing MOSFET attaching hardware. • A soldering iron and desoldering tool. • An NX50 spares kit (contains replacement semi-conductors). Electrostatic Precautions The RF power module contains semiconductor devices that are susceptible to damage from electrostatic discharge.
  • Page 67 NX50 Troubleshooting Manual Responding to alarms 5. If the measurements in Step 3 Step 4 are satisfactory, but the RF power module continues to display alarms when installed in the transmitter, replace the RF power module. Resistance measurements Complete the following resistance measurements for each suspect RF power module.
  • Page 68 2. If the diode is not satisfactory, replace it by desoldering its surface-mount leads and case from the PWB. A replacement diode can be purchased from Nautel (Part # QM64). Note the correct orientation when soldering the replacement to the PWB.
  • Page 69 NX50 Troubleshooting Manual Responding to alarms Figure 1.7: RF Power Module MOSFET and Diode Location Free-wheel diodes (CR19, CR20 and CR21) CR20 CR21 CR19 G D S G D S G D S Modulator MOSFETs (Q11, Q12 and Q13) Protection diode...
  • Page 70 5. Ensure the surface of the heatsink is clean and free of debris. 6. Obtain a replacement MOSFET (Nautel Part # QR68) and a new thermal pad (Nautel Part # HAK55) from the spares kit, if purchased, and install them on the RF power module chassis using the two M4 screws removed in step 3.
  • Page 71 NX50 Troubleshooting Manual Responding to alarms Figure 1.8: Power Amplifier FET Replacement Issue 6.0 2019-04-01 Page 1-61...
  • Page 72 7. Obtain a replacement device (modulator FETs are Nautel Part # QR75; free-wheel diodes are Nautel part # QK50) from the spares kit, if purchased. Apply a thin film of thermal compound (Nautel Part # HAG39, from the ancillary kit) to the device.
  • Page 73 NX50 Troubleshooting Manual Responding to alarms 8. Install the device on the heat sink using the punched hole in the heat sink as an alignment aid. Apply downward pressure on the device and wiggle it slightly left and right and up and down to release trapped air and excess thermal compound. Reinstall...
  • Page 74 6. Remove and retain 13 sets of mounting hardware from the control/interface PWB (A11A1). 7. Obtain a replacement control/interface PWB (Nautel Part # NAPC160B/01). 8. Set the EXT CONT INTLK (E1) and REMOTE SUPPLY (E3) jumpers on the replacement PWB to the same positions as the defective PWB.
  • Page 75 NX50 Troubleshooting Manual Responding to alarms installed on the transmitter. See the NX50 Operations and Maintenance Manual for detailed instructions. 11. Re-enter all the AUI information recorded in Step 12. Set the time using the front panel AUI’s Factory Settings - Time Setup page.
  • Page 76 NX50 Troubleshooting Manual Responding to alarms Remote interface PWB replacement 1. Set the transmitter to its RF Off state. Open the front door to gain access to the exciter panel (see Figure 1.9 on page 1-65). 2. If applicable, label each of the connectors connected to the remote interface PWB to indicate their connection point.
  • Page 77 PROGRAM position (shorting pins 1 and 2). Press RESET switch S1, located directly above E1. 4. Obtain the NCode Uploader application from Nautel’s FTP site: ftp://www3.nautel.com/Utilities/NCodeUploader/ 5. From the PC, run the NCode Uploader (version 1.8 or higher) application (see Figure 1.11 on page...
  • Page 78 In this case, repeat Step 2 through Step 7 for the operational exciter’s digital AM exciter PWB. If there is no operational exciter, contact Nautel for the required calibration data. Page 1-68 Issue 6.0 2019-04-01...
  • Page 79 12. Obtain a replacement digital AM exciter PWB (Nautel Part # NAPE78A/01). 13. Install the new digital AM exciter PWB by reversing...
  • Page 80 NX50 Troubleshooting Manual Responding to alarms 16. On the digital AM exciter PWB’s MODE program header E1 (see Figure 1.10 on page 1- 67), install the shorting jumper in the PROGRAM position (shorting pins 1 and 2). Press RESET switch S1, located directly above E1.
  • Page 81 3. Carefully remove and retain four (4) sets of mounting hardware from the GPS sync PWB from the exciter panel. 4. Obtain a replacement GPS sync PWB (Nautel Part # NAPX46). Remove the jack screws from 9-pin D-sub connector J1 on the new GPS sync PWB before installing it.
  • Page 82 3. Carefully remove and retain four (4) sets of mounting hardware from the USB audio interface PWB from the exciter panel. 4. Obtain a replacement USB audio interface PWB (Nautel Part # NAPI151). 5. Install the new USB audio interface PWB by reversing...
  • Page 83 PWB. 3. Remove and retain six (6) sets of mounting hardware. 4. Remove the defective PWB from the transmitter. 5. Obtain a replacement PDM Drive Distribution PWB (Nautel Part # NAPI154). 6. Reverse Step 2...
  • Page 84 NX50 Troubleshooting Manual Responding to alarms RF drive distribution PWB replacement WARNING: Lethal voltages exist inside the transmitter when the power is turned on. Turn off (disable) and lock out the power at the source and verify no dangerous ac or dc voltages are present before removing any connections or PWBs.
  • Page 85 NX50 Troubleshooting Manual Responding to alarms Figure 1.17: Rack Interface Cover RF Drive PWB Rack Interface PWB Note the two (2) white wires Location of six (6) M3 screws that passing through the cover secure the Rack Interface Cover Figure 1.16 Figure 1.17 on page...
  • Page 86 NX50 Troubleshooting Manual Responding to alarms 6. Obtain a replacement RF Drive Distribution PWB (Nautel Part # NAPI98). 7. Reverse Step 2 through Step 5 to install the replacement PWB. Ensure all connections are tight. For connector mating assistance, refer to the connector mating tables in Section 3, “Wiring/connector lists”...
  • Page 87 PWB disengages from the three (3) D-sub connectors on the front edge of the board which mate to the power module interface PWBs. 7. Obtain a replacement Rack Interface PWB (Nautel Part # NAPI152C) and set DIP switch S1 as follows:...

  • Page 88: Scr Rectifier Inspection/Replacement

    NX50 Troubleshooting Manual Responding to alarms SCR Rectifier Inspection/Replacement WARNING: Lethal voltages exist inside the transmitter when the power is turned on. Turn off the power at the source and verify the 20 bright green LEDs on the power module interface PWBs are off before removing any connections or PWBs.
  • Page 89 4. Remove and save (6) sets of M5 mounting hardware that support the SCR rectifier assembly. 5. Carefully lift and remove the SCR rectifier assembly from the transmitter. 6. Obtain a replacement SCR rectifier assembly (Nautel Part # 207-7055-05). 7. Reverse Step 3...

  • Page 90: Rectifier Fan Inspection/Replacement

    Philips screws securing it to the top of A48. 4. Replace the fan with a suitable replacement (Nautel Part # 207-8378). 5. Secure the replacement fan to the SCR rectifier assembly and connect the fan’s wiring as it was previously installed.

  • Page 91: Low Voltage Power Supply Replacement

    NX50 Troubleshooting Manual Responding to alarms Low Voltage Power Supply Replacement WARNING: Lethal voltages exist inside the transmitter when the power is turned on. Turn off (disable) and lock out the power at the source and verify no dangerous ac or dc voltages are present before removing any connections or PWBs.
  • Page 92 NX50 Troubleshooting Manual Responding to alarms Figure 1.19: Location of Low Voltage Power Supplies 15 V Power Supplies U3 (A) and U4 (B) 48 V Power Supplies U5 (A) and U6 (B) 12 V Power Supply U7 Back Door and Side Panel Removed for Clarity 3.
  • Page 93 Responding to alarms 6. Obtain a replacement power supply module noting: • The +15 V power supply module is Nautel Part # UG53 • The +48 V power supply module is Nautel Part # UG54 • The +12 V power supply module Nautel Part # UG57 7.

  • Page 94: Rf Power Module Fan Tray Replacement

    You can also replace an individual fan of a fan tray assembly. See “RF Power Module Fan Tray Cooling Fan replacement” on page 1-85. 5. Obtain a replacement fan tray (Nautel Part # 207-8133). 6. Reverse Step 1 through Step 4 to install the new fan tray assembly.

  • Page 95: Rf Power Module Fan Tray Cooling Fan Replacement

    3. Remove and retain the cooling fan’s two (2) M4 screws that secure the fan to the tray. 4. Obtain a replacement fan (Nautel Part # ZAP37) from the site spares kit, if purchased (vendor part # is Sanyo Denki America Inc. 109E5748C503).

  • Page 96: Touchscreen Monitor Replacement

    4. Remove the four (4) brackets securing the monitor (see Figure 1.22) and retain all hardware (M4 nuts, split washers and flat washers). Remove the defective monitor. 5. Obtain a replacement monitor (Nautel Part # UR108). Reverse Step 1 through Step 4 to install.

  • Page 97: Single Board Computer (Sbc) Replacement

    NX50 Troubleshooting Manual Responding to alarms 6. The new monitor may require calibration after installation. If necessary, connect a USB mouse to a USB port on the Single Board Computer and do the following: • On the local AUI, go to Menu > System Settings > Screen Configuration .
  • Page 98 4. Disconnect the remaining connectors from the current SBC. Remove the SBC from the front door by removing its seven (7) M3 securing screws. 5. Locate or obtain the replacement SBC (Nautel Part # 207-8710-01). Obtain the flash card (see Figure 1.23 on page...
  • Page 99 NOTE: If the AUI fails to load, confirm the BIOS boot option setting is correct. Download IS18005* from the Nautel FTP site for further instructions; ftp:// www3.nautel.com/NX_Series/ 8. Once the AUI is rebooted, go to the System Settings page and select Upgrade Software to view the files in the Select Upgrade File list.

  • Page 100: Arc Detector Uv Sensor Replacement

    NX50 Troubleshooting Manual Responding to alarms Arc Detector UV Sensor Replacement WARNING: Lethal voltages exist inside the transmitter when the power is turned on. Turn off (disable) and lock out the power at the source and verify no dangerous ac or dc voltages are present before removing any connections or PWBs.
  • Page 101 PWB (U1) through the hole on top of the enclosure (see Figure 1.26 on page 1-92). 4. Obtain a replacement UV sensor (Nautel Part # UB89). WARNING: Take special care when handling the UV sensor after removing it from the packaging so it does not receive impact shock.
  • Page 102 NX50 Troubleshooting Manual Responding to alarms Figure 1.26: Arc Detector Assemble UV Photo Tube Sensor (UB89) Cathode Lead Anode Lead Assembly may not be exactly as shown Figure 1.27: UB89 Orientation on Driver PWB U1 Connect Anode Connect Cathode Lead here...

  • Page 103: Rf Voltage Probe Replacement

    NX50 Troubleshooting Manual Responding to alarms RF Voltage Probe Replacement WARNING: Lethal voltages exist inside the transmitter when the power is turned on. Turn off (disable) and lock out the power at the source and verify no dangerous ac or dc voltages are present before removing any connections or PWBs.
  • Page 104 4. Remove and retain the two M5 screws that secure the voltage probe to the side of the transmitter’s chassis. 5. Obtain a replacement RF Voltage Probe (Nautel Part # 207-6111-01). 6. Complete the replacement procedure by reversing Step 2 Step 7.

  • Page 105: Rf Current Probe Replacement

    NX50 Troubleshooting Manual Responding to alarms RF Current Probe Replacement WARNING: Lethal voltages exist inside the transmitter when the power is turned on. Turn off (disable) and lock out the power at the source and verify no dangerous ac or dc voltages are present before removing any connections or PWBs.
  • Page 106 7. Using a 13-mm socket, remove and retain the three M8 bolts and hardware. When re- installing the bolts, tighten appropriately (no torque setting recommended). 8. Obtain a replacement RF Current Probe (Nautel Part # 207-6213-10). 9. Complete the replacement procedure by reversing...
  • Page 107 NX50 Troubleshooting Manual Responding to alarms Figure 1.30: Location of Mounting Hardware M8 BOLTS Partial View; Rear Door and LHS Quantity 3 panel removed for clarity M12 BOLT Issue 6.0 2019-04-01 Page 1-97...
  • Page 108 NX50 Troubleshooting Manual Responding to alarms Page 1-98 Issue 6.0 2019-04-01...

  • Page 109: Parts Lists

    Nautel configuration control number. • Locate the part's reference designation and associated Nautel Part # in the list provided at the end of this section. In a PDF manual, use Ctrl-F (find) to quickly locate the reference designation.

  • Page 110: Column Content

    This number represents the level of a component in relation to the highest level parts list. In this case the highest level parts list is the NX50’s overall parts list, or the top block in the family tree shown in (Figure 2.1...
  • Page 111 Note: This section includes Nautel part numbers only. It does not include original equipment manufacturer (OEM) information (i.e., vendor part numbers). Some vendor information is provided in the Responding to Alarms section of this manual, otherwise contact Nautel to order a replacement part or to request assistance to find a suitable replacement.

  • Page 112: Common Abbreviations/Acronyms

    NX50 Troubleshooting Manual Parts Lists Common abbreviations/acronyms The following abbreviations/acronyms may appear in the Description of Part column: • SMT Denotes item is designed to be installed using Surface Mount Technology. • MTA Denotes item is a Mass Termination Assembly connector.
  • Page 113 NX50 Troubleshooting Manual Parts Lists Figure 2.1: NX50 Family Tree (Sheet 1 of 2) 50 kW AM BROADCAST TRANSMITTER NARA53E A1 - A5 RF COMBINER BACK PLANE RACK INTERFACE PWB RF DRIVE DISTRIBUTION PWB NAH57C/01 NAPI152C NAPI98 A1A1 - A5A1...
  • Page 114 NX50 Troubleshooting Manual Parts Lists Figure 2.2: NX50 Family Tree (Sheet 2 of 2) DIRECTIONAL COUPLER STATIC DRAIN CHOKE CAPACITOR ASSEMBLY NAFP106B/01 183-6059 NOT USED 207-7120-04 A43A1 DIRECTIONAL COUPLER PWB NAPP10/01 ARC DETECTOR ASSEMBLY 25/50 kW RECTIFIER ASSEMBLY 215-8065 207-7055-05...
  • Page 115 Capacitor, Ceramic, 0.1uF 10% 100V CS68 Capacitor, Non-Polarized, 10uf , +/-20%, 35V UR92 Rectifier, (BeO), SCR, 3-PH, 400VDC, 250A 207-7120-04 Capacitor Assy-NX50 RLS 3 & 4 207-8611-01 Discharge Relay Assy KC76 Relay, 12KV, NC, 180V, AUX SW, Ext Range CT54 Capacitor,Elect.,10,000uf,450V dc...
  • Page 116 UA82 Cable, 6 ft.,9-pin D-Sub,M/F, Straight-Through W66, W67 UB75 Cable 6ft, 18AWG, Plug Ø 2.1mm /5.5mm 207-8505-02 Cableform, B+ P/S, NX50, RLS 3 207-8508-01 Cableform, RF NX50 (RLS 3) UA201 Cable, Ethernet, 70", Shld, Bl ack, 28AWG, 80degC, W25, W27 UA203 Cable, Ethernet, 56", Shld, Bl ack, 28AWG, 80degC,...
  • Page 117 Equipment Hardware Kit (Metric ) 207-1038 Dummy Module Assy Nx Series 207-8428 AC Entry Adapter Plate Asy for WG53 207-8517-01 Cableform, AC/Rect O/P & Stn GND, NX50, RLS 4 215-8065 Arc Detector Shielded Assy CCF06 Capacitor, Tantalum, Epoxy, 1u F 10% 35V U01CX JT157 Header, 4-pin, Square, Pol, 0.1", Rt Angle, PCB mo...
  • Page 118 NARA53E Page 4 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation CCFS10 Cap,SMT,Ceramic,1uF,10%,25V, ,X7R,1206 C003, C004, C011, C012, C013, C014, C019, C020, C021, C023, C025, C027, C031, C035, C043, C044,, C045, C046, C080, C082, C084, C090, C092, C094, C099, C102, C105,...
  • Page 119 NARA53E Page 5 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation JT121 Conn, Dual, D-Sub, F/M, 9 pin, Rt. Angle, PWB JT61 Conn, BNC, Recept, 50ohm,Insul , Rt Angle J07, J08 JT87 Conn,3-pin,PWB Mount, Fem, XLR...
  • Page 120 NARA53E Page 6 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation RAD55Z Resistor,SMT,150 Ohms,, 1%,2W R180 RAE02 Resistor, SMT, MF, 121K Ohms, 1% 1/4W R004, R005, R007, R008 RAE34 Resistor,SMT,MF,49.9R,1%,1/10W 0603 R001, R002, R061, R062, R103, R104, R115, R116, R119,...
  • Page 121 NARA53E Page 7 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation RFFS50 Resistor,SMT,MF,10.0Kohms,1%, 1/10W,0603 R014, R023, R034, R063, R064, R070, R074, R075, R076, R081, R082, R094, R101, R102, R107, R112,, R113, R123, R124, R125, R140, R146, R151, R153, R158, R159, R160,...
  • Page 122 NARA53E Page 8 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation UDLS04 IC,SMT,CMOS,8-Bit Shft Reg,Par I/P, SOIC-16 U69, U71 UDLS05 IC,SMT,CMOS,8-Bit Shft Reg,Par O/P, SOIC-16 U26, U27, U72, U73 UDLS06 IC,SMT,CMOS,Quad Tri-State Buf fer, SOIC-14...
  • Page 123 NARA53E Page 9 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation CCFS10 Cap,SMT,Ceramic,1uF,10%,25V, ,X7R,1206 C013, C017, C028, C029, C070, C074 CCFS23 Cap,SMT,Ceramic,18pF,2%,50V, C0G,0603 C069, C077 CCFS24 Cap,SMT,Ceramic,22pF,2%,50V, C0G,0603 C001, C004 CCFS32 Cap,SMT,Ceramic,100pF,2%,50V, C0G,0603...
  • Page 124 NARA53E Page 10 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation LS21 Inductor,SMT,390nH,375mA,2520 L01, L03, L04, L06 QDLS01 Diode, SMT, LED, Green, (560nm), 0603 DS01, DS02, DS03, DS04 RAE34 Resistor,SMT,MF,49.9R,1%,1/10W 0603 R21, R23, R36, R38, R39, R40, R43, R54, R55, R56 RFFS02 Resistor,SMT,MF,1.00ohms,1%, 1/10W,0603...
  • Page 125 NARA53E Page 11 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation UP95 IC,SMT,Stereo ADC,24bit,96kHz, TSSOP-28 UT100 Oscillator,SMT,25MHz,3.3V UT124 Oscilitor, SMT, VCXO,158.76MHz LVPECL, 3.3V, 9x14m UT93 IC,SMT,Voltage Regulator,5V, 1A, D2PAK UT98 Oscillator,SMT,TCVCXO,10MHz, 3.3V,2ppm UW109...
  • Page 126 R13, R14, R15, R16 SA60 Switch,SMt,Mom.,1PSTNO S01, S02, S03, S04, S05, S06, S07, S08, S09, S10, S11, S12, S13, S14, S15, S16 NAFP106B/01 Directional Coupler (FWD/REFL PWR) for NX50 207-6052-01 Transformer Current Assy CCG42 Capacitor, Ceramic, 50pF +10% 15000V NAPP10/01...
  • Page 127 NARA53E Page 13 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation JU02 MTA, Standard Dust Cover, 4 pi n JU27 MTA, Keyed Closed End Housing, 4 pin,22AWG KA60 Relay, Latching, 100A, Dbl Coi l, Reverse Polarity...
  • Page 128 NARA53E Page 14 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation CCFS07 Cap,SMT,Ceramic,0.1uF,10%,50V, X7R,0805 C001, C006, C007, C008, C011, C012, C013, C014, C017, C018, C022, C026, C027, C044, C049, C058,, C061, C062, C066, C068, C069, C072, C075, C078, C080, C082, C083,...
  • Page 129 NARA53E Page 15 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation RAD14 Resistor, SMT, MF, 121 Ohms, 1% 1/4W R046, R047, R076, R094 RAD17 Resistor, SMT, MF, 221 Ohms, 1% 1/4W R014, R015...
  • Page 130 NARA53E Page 16 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation UT93 IC,SMT,Voltage Regulator,5V, 1A, D2PAK UX184 IC, SMT, Micro, ADC, PWM, TQFP-32, 16k Flash XFPS11 Crystal, SMT, Fund, 11.0592MHz QR68 Transistor, FET, N Channel, 500V, 0.05ohm fast...
  • Page 131 NARA53E Page 17 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation HR26 Connector, Quick-Dis, M, 1/4 Tab, PWB E01, E02 JF47 Conn, Header,Square Post,Gold, Dual,40-pin JQ34 Conn, Socket, D-Sub, 9 pin, PW B Mt...
  • Page 132 NARA53E Page 18 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation RFFS40 Resistor,SMT,MF,1500ohms,1%, 1/10W,0603 R006, R048, R153, R155, R163, R164, R165 RFFS41 Resistor,SMT,MF,1820ohms,1%, 1/10W,0603 R007 RFFS42 Resistor,SMT,MF,2210ohms,1%, 1/10W,0603 R136 RFFS44 Resistor,SMT,MF,3320ohms,1%, 1/10W,0603 R104...
  • Page 133 NARA53E Page 19 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation UDLS06 IC,SMT,CMOS,Quad Tri-State Buf fer, SOIC-14 UDMS01 IC, SMT, SRAM, 32Kx8, SOIC-28 (Wide) UDMS02 IC, SMT, Micro, ADC, PWM,Flash , TQFP-64 UDOS01...
  • Page 134 NARA53E Page 20 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation RFFS01 Resistor,SMT,MF,0.0ohms,Jumper ,0603 R01, R02, R03, R04, R05, R06, R07, R08, R09, R10, R11, R12, R13, R14, R15, R16 RFFS34 Resistor,SMT,MF,475ohms,1%, 1/10W,0603...
  • Page 135 NARA53E Page 21 of 21 StockCode: Description: Final Assy, NX50, RLS 6, Component Lvl, StockCode Description Reference Designation FD24 Fuse, 70A, 600V, Class J, Open Indicator F01, F02, F03, F04, F05 JDP26 Conn, Coax, BNC, Recept, 50ohm RD45 Resistor, Film, 68.1K Ohms, 0.1%, 1W...

  • Page 136: Wiring/Connector Lists

    NX50 Troubleshooting Manual Wiring/connector lists Section 3: Wiring/connector lists This section contains the wiring information for the hard-wired assemblies of the transmitter, and applicable connector mating information. Wiring lists provided Wiring lists are provided in tabular format. Table 3.1 on page 3-2 lists the tables containing wiring information.
  • Page 137 Table # Description Table 3.3 NX50 Transmitter - Wiring List (page 3-2) Table Fan Tray Assembly (Nautel Part # 207-8133) - Wiring List, (page 3-2) Table 3.2: Connector Mating Information Provided Table # Description Table 3.5 NX50 Transmitter - Connecting Mating Information...
  • Page 138 NX50 Troubleshooting Manual Wiring/connector lists Table 3.3: NX50 Transmitter - Wiring List (Continued) Source Destination Wire # Color Size Remarks A3A1E2 A46C3-(-) Black A4A1E2 A46C4-(-) Black A5A1E2 A46C5-(-) Black A46C6-(-) A46C5-(-) Black A46U8-(AC1) A46C1-(+) White A46U8-(AC2) A46C2-(+) White A46U9-(AC1) A46C3-(+)
  • Page 139 NX50 Troubleshooting Manual Wiring/connector lists Table 3.3: NX50 Transmitter - Wiring List (Continued) Source Destination Wire # Color Size Remarks P05-01 P07-04 White P05-02 GND near A39 Black P05-03 P06-23 White P05-04 P07-05 White P05-05 GND near A39 Black P05-06...
  • Page 140 NX50 Troubleshooting Manual Wiring/connector lists Table 3.3: NX50 Transmitter - Wiring List (Continued) Source Destination Wire # Color Size Remarks P09-17 A48U1TB3-16 Centre 1-Conductor shielded P09-04 A48U1TB3-17 Shield P09-18 A48U1TB1-8 Centre 1-Conductor shielded P09-06 A48U1TB2-3 Shield P09-19 A48U1TB1-4 Centre 1-Conductor shielded...
  • Page 141 NX50 Troubleshooting Manual Wiring/connector lists Table 3.3: NX50 Transmitter - Wiring List (Continued) Source Destination Wire # Color Size Remarks P13-01 U4-(V+) White P13-02 U4-(V-) Black P17-01 P27-04 White Coax,50 Ohms RG188A/U P17-06 P27-01 Shield P17-03 P23-Centre Centre Coax,50 Ohms RG188A/U...
  • Page 142 NX50 Troubleshooting Manual Wiring/connector lists Table 3.3: NX50 Transmitter - Wiring List (Continued) Source Destination Wire # Color Size Remarks U7-L A46K1-TB1-1 White U7-N A46K1-TB1-2 White A48U1TB3-4 A46K1-AUX-NO Center A48U1TB3-18 A46K1-Chassis Shield P33-6 A11A1TB1-11 Centre Coax,50 Ohms RG188A/U P33-8 A11A1TB1-12...
  • Page 143 NX50 Troubleshooting Manual Wiring/connector lists Table 3.3: NX50 Transmitter - Wiring List (Continued) Source Destination Wire # Color Size Remarks T1-LOAD1 T1A1XF1-1 White T1-LOAD0 T1A1XF1-3 White T1A1U1-2 T1A1XF1-1 White T1A1U2-2 T1-LOAD2 White T1A1U3-2 T1-LOAD3 White T1-LOAD1 A48U1-AC1 Black T1-LOAD2 A48U1-AC2...
  • Page 144 NX50 Troubleshooting Manual Wiring/connector lists Table 3.4: NX50 Transmitter - Connector Mating Information (Continued) Connector Mate Note A47U1J1 Arc Detector PWB U3CN3 To U3: +15V P/S A36J1 Fan Tray U4CN3 To U4: +15V P/S A42J1 Current sample A41J1 Voltage sample...
  • Page 145 NX50 Troubleshooting Manual Wiring/connector lists Table 3.4: NX50 Transmitter - Connector Mating Information (Continued) Connector Mate Note W18P2 A8J4G W19P1 A24A1J1 W19P2 A8J5F W1P1 A15A1J1 W1P2 A8J1B W20P1 A34A1J1 W20P2 A8J5G W21P1 A7J3F W21P2 A1A1J11 W22P1 A7J3D W22P2 A1A1J12 W23P1...
  • Page 146 W70P2 A5A1J6 W7P1 A18A1J1 W7P2 A8J4B W8P1 A28A1J1 W8P2 A8J4C W9P1 A19A1J1 W9P2 A8J5B Table 3.5: Fan Tray Assembly (Nautel Part # 207-8133) - Wiring List Source Destination Wire # Color Size Remarks J1-01 J1-02 Black J1-03 Yellow TACH J1-04...
  • Page 147 NX50 Troubleshooting Manual Wiring/connector lists Table 3.6: Fan Tray Assembly (Nautel Part Number: 207-8139) - Connector Mating Information Connector Mate Note B1E1 Fan 1 Red Wire (V+) B1E2 Fan 1 Black Wire (V-) B1E3 Fan 1 Yellow Wire (TACH) B2E1...

  • Page 148: Reading Electrical Schematics

    • Resistor power ratings are not shown when less than 0.5 W • Capacitor values are shown in microfarads (uF) • Unidentified diodes are part number 1N4938 (Nautel Part # QAP29) Graphic symbols The graphic symbols used on electrical schematics are in accordance with American National Standard ANSI Y32.2-1975 - Graphic Symbols for Electrical and Electronic Diagrams.

  • Page 149: Unique Symbols

    NX50 Troubleshooting Manual Reading Electrical Schematics Unique symbols Nautel uses unique symbols on electrical schematics to describe logic (two-state) signals. These signals differ from single-state signals or analog signals that may have multiple values. Type of inputs and outputs On electrical schematics, names used to describe logic (two-state) input and output signals are prefixed with a # symbol.

  • Page 150: Structure Of Schematics

    Section 2, “Parts Lists” on page 2-1. Follow the family tree branches to the block that contains the desired reference designation, and associated Nautel nomenclature (e.g., NAPA34A Modulator/Power Amplifier PWB ). Note the reference designations and Nautel nomenclatures of all higher assemblies in the path.

  • Page 151: Locating A Part Or Assembly On A Schematic

    2-1. 2. Follow the family tree branches to the block that contains the desired reference designation, while noting the Nautel nomenclatures and names of all higher assemblies in the path. Example: A15 NAP39A RF Power Module > A15A1 NAPA34A Modulator/ Power Amplifier PWB .
  • Page 152 NX50 Transmitter - Exciter Stage SD-3 NX50 Transmitter - Control/Monitor Stage SD-4 NX50 Transmitter - RF Power Stage (Sheet 1 of 2) SD-5 NX50 Transmitter - RF Power Stage (Sheet 2 of 2) SD-6 NX50 Transmitter - NX50 RF Power Block...
  • Page 153 NX50 Troubleshooting Manual Reading Electrical Schematics Page 4-6 Issue 6.0 2019-04-01...
  • Page 154 INHIBIT 48V (B) - INTERNAL BUS (+) INTERNAL BUS (-) +15V U1J1 DETECTOR ASSY # ARC DETECT - 12V POWER CONTROL/ +12V SUPPLY MONITOR 200W STAGE 207-8500-05 SCH02 VA Figure SD-1: NX50 Transmitter - Ac-Dc Power Stage Issue 6.0 2019-04-01 SD-1...
  • Page 155 EXT 10 MHz # RF DRIVE LATCH (EXCITER B) - REFLECTED POWER SAMPLE STREAMING BUS (EXCITER B) FROM RF POWER +15V STAGE RF VOLTAGE SAMPLE -15V RF CURRENT SAMPLE S2070233 V2 Figure SD-2: NX50 Transmitter - Exciter Stage Issue 6.0 2019-04-01 SD-2...
  • Page 156 SYNC (GPS) CONTROLLER INTERNAL BUS (+) (OPTIONAL) GPS ANTENNA # INTERLOCK - # ADDRESS (GPS) - (N/U) # SYNK OK (GPS) - INTERNAL BUS (+) S2070234 V5 AES/EBU AUDIO (*) Figure SD-3: NX50 Transmitter - Control/Monitor Stage Issue 6.0 2019-04-01 SD-3...
  • Page 157 W61P2 NOTE: SEE FIGURE SD-6 FOR 10 kW RF POWER BLOCK DETAIL PDM 1 (+) PDM 1 (-) (PART 1 OF 5) (PART 2 OF 5) (PART 3 OF 5) (PART 4 OF 5) (PART 5 OF 5) PDM 2 (+) PDM 3 (+) GROUP A PDM 3 (-)
  • Page 158 CAPACITOR BANK 3 RF TRANSFORMER PART OF A5 (SAME AS ABOVE) CAPACITOR BANK 1 CAPACITOR BANK 2 RF OUT TO ANTENNA CONTROLLED SURGE DIRECTIONAL SPARKGAP GROUND 50pF STATIC TO SHEET ? ARRESTOR COUPLER SWITCH DRAIN 5000V STN GND (OPTIONAL) * DENOTES FREQUENCY DEPENDENT COMPONENTS (REFER TO CUSTOMER CONFIGURATION SHEET FOR CAPACITOR VALUES) 1000...
  • Page 159 PDM 3 (+) A1J1 A1J1 PDM 3 (-) PDM 3 (-) 1N4004 1N4004 PDM 2 (-) PDM 2 (-) 207-8500-05 SCH01 VA DUMP (+) DUMP (+) DUMP (-) DUMP (-) Figure SD-6: NX50 RF Power Block Issue 6.0 2019-04-01 SD-6...
  • Page 160 MINOR MAJOR LOCAL REMOTE RF ON RF OFF INHIBIT ALARM ALARM C142 C152 C163 C160 R202 R209 R214 R217 R222 R233 R241 I/O7 PH2/XCK2 I/O6 PH3/OC4A AVCC I/O5 C144 PH4/OC4B I/O4 PH5/OC4C U56:H I/O3 RF_DRIVE_SAMPLE PH6/OC2B FROM SHEET 2 PF0/ADC0 U56:G I/O2 PH7/T4...
  • Page 161 MINOR MAJOR LOCAL REMOTE RF ON RF OFF INHIBIT ALARM ALARM C142 C152 C163 C160 R202 R209 R214 R217 R222 R233 R241 I/O7 PH2/XCK2 I/O6 PH3/OC4A AVCC I/O5 PH4/OC4B C144 I/O4 PH5/OC4C U56:H I/O3 RF_DRIVE_SAMPLE PH6/OC2B FROM SHEET 2 U56:G PF0/ADC0 I/O2 R139...
  • Page 162 TP51 #PDM_LATCH_RESET- FROM SHEET 1 #PDM_LATCH- U43:A +3.3V +3.3V TO SHEET 1 10.0K MODULATION_SAMPLE 10.0K U43:B 1.00M U29:C 10.0 10.0K +3.3V 10.0K U2:A U43:E 1.00M U29:A MM74HC00M PDM 1 C129 +3.3V U15:A U30:E PDM 1 MC3302D 1.00M U30:C U5:A +3.3V PDM 1 74LVC257APW 1000...
  • Page 163 CR45 U55:A DIGITAL TO ANALOG R195 +15V -15V CONVERTER 10.0K C166 CR43 R194 R199 R200 220pF 2210 BALANCED R189 R182 DACA ANALOG C213 U74:A ANALOG OUT (RMT I/FACE) 1 BALANCED R257 AUDIO 0.01 R309 C264 R345 ANALOG SHIELD 10.0K 10.0 10.0 C211 C210...
  • Page 164 REMOTE INPUTS REMOTE INPUTS R286 R278 4750 4750 +15V-A +15V-A R328 R320 +15V +15V (REMOTE) R308 C247 U82:A R300 C239 U78:A 4750 4750 C268 CR76 CR68 10.0K 0.01 MOCD223-M 10.0K 0.01 MOCD223-M RXE110 # DIGITAL INPUT 01 - # DIGITAL INPUT 09 - R285 R277 4750...
  • Page 165 REFLD_PWR_SAMPLE RF MON S5:A FWD PWR SAMPLE RF MONITOR R226 R225 VINP VOUT 3320 R180 10.0K U60:A R213 C174 FDBK 1000 U83:C R329 REFLD S5:B # DIGITAL OUT 01 - REFLD PWR SAMPLE R208 C226 C222 U83:D 12.1 R330 RESET R224 R211 1000...
  • Page 166 TP49 1 PPS (GPS) 74LVC257APW 74LVC257APW 1 PPS (EXCITER A) 1KHz (GPS) R116 1 PPS (EXCITER B) 49.9 10MHz (GPS) R101 R102 R113 10.0K 10.0K 10.0K 1 PPS (EXGINE) R115 49.9 1 PPS (COMB CONT) U45:A 10MHz (EXGINE) R119 R134 C120 49.9 R135...
  • Page 167 +15V +15V +15V +15V +15V +15V +15V +15V # DIGITAL INPUT 01 - # DIGITAL INPUT 01 - DS1:B DS1:A DS2:B DS2:A DS9:B DS9:A DS10:B DS10:A E1:1 E1:3 E2:1 E2:3 E9:1 E9:3 E10:1 E10:3 # DIGITAL INPUT 02 - # DIGITAL INPUT 02 - STATUS ALARM STATUS...
  • Page 168 TP10 +3.3V +3.3V LP38500TS-ADJ REF3033AIDBZT VREF 10.0K +3.3V 2210 +3.3V 10MHz #RECEIVER_ENABLE- +3.3V VOUT I/O/GCK3 OC14C-10M000 49.9 DAC8531E 10.0K +3.3V +3.3V MCP120T-270I/TT # SYNC OK - F3M3 RESET PD6/WR 49.9 +3.3V PC4/TCK/A12 SYNC +3.3V +3.3V PWRIN SCLK 1 PPS F2M4 FDC640P 0.001 F4M4...
  • Page 169 U2:A VBUS DOUT AES/EBU 22.1 OUTPUT 1 SSPND U2:D SHLD VOUTL 22.1 VOUTR PSEL 1500 TEST1 PCM2705DB TEST0 U2:C DGND 1500 ZGND AGNDL AES/EBU OUTPUT 2 AGNDR HID0/MS U2:B PGND SHLD HID1/MC HOST HID2/MD VCOM VCCL U2:E VCCR SN74AHC86D 12.000MHz 18pF 1.00M VCCP...
  • Page 170 RESET SERIAL INTERFACE MOSI DO/RI MISO DC_CURRENT INTERNAL BUS TP54 (IN) R182 R202 AC_SAMPLE FROM 4750 4750 10.0K DO/RI R181 SHEET 2 RESET PE0/RXD0/PDI ADM803MAKS B+_LEVEL DS36C278TM S1:3 S1:4 TP57 RESET LAST INTERNAL BUS MISO RACK R180 R193 R194 (OUT) PROG VCC PE1/TXD0/PDO 49.9...
  • Page 171 CTRL RACK B+ SAMPLE S1:7 U12:D B+ SAMPLE S1:5 6810 S1:8 NX25 TP69 S1:6 R164 R204 1500 U27:C CTRL RACK 68.1K R188 # 15V PS OK A - R166 C174 0.47 TP38 DC_CURRENT TP68 AC_SAMPLE R165 U20:A TO SHEET 1 1500 U27:B R138...
  • Page 172 +15V TO SHEETS 1 & 2 +15V TO SHEETS 1 & 2 +48V-A_SAMPLE PWB PART: HR67_S R175 C137R143 C116 22.1K R176 475K +15V 1000 C145 C144 APXW012A0X3 STPS40L15CW +15V (RECTIFIER) +5V (CONTROL) RT11 +48V-B_SAMPLE VOUT RUEF600 ON/OFF TO SHEET 2 +15V (CONTROL) R174 C136...
  • Page 173 U31:D RF DRIVE 1 U31:A U16:A U20:A U24:A 82.5 82.5 U16:B U20:B U24:B C102 U4:A U8:A U12:A IDT74FCT807CTSO U4:B IDT74FCT807CTSO U8:B IDT74FCT807CTSO U12:B C101 U15:A U19:A U23:A U15:B U19:B U23:B U3:A U7:A U11:A U3:B U7:B U11:B ENABLE ENABLE RF DRIVE 1 RF DRIVE 1 RF DRIVE 1 U31:E...
  • Page 174 U31:C RF DRIVE 2 U31:B U16:C U20:C U24:C 82.5 82.5 U16:D U20:D U24:D U4:C U8:C U12:C IDT74FCT807CTSO U4:D IDT74FCT807CTSO U8:D IDT74FCT807CTSO U12:D ENABLE ENABLE U19:E U15:C U19:C U23:C DS26C31TM U15:D U19:D U23:D ENABLE ENABLE U7:E DS26C31TM U3:C U7:C U11:C U3:D U7:D U11:D ENABLE...
  • Page 175 U7:A U15:A U23:A U31:A U39:A PDM_A1 PDM 1 PDM_A1 PDM 1 PDM_A1 PDM 1 PDM_A1 PDM 1 PDM_A1 PDM 1 U7:B U15:B U23:B U31:B U39:B PDM_A2 PDM 2 PDM_A2 PDM 2 PDM_A2 PDM 2 PDM_A2 PDM 2 PDM_A2 PDM 2 MODULE MODULE MODULE...
  • Page 176 U1:C PDM_A1 ENABLE ENABLE ENABLE ENABLE PDM 1 U1:E U20:E DS26C32ATM DS26C31TM 82.5 82.5 ENABLE ENABLE ENABLE ENABLE U2:E U21:E DS26C32ATM DS26C31TM U1:D PDM_A2 PDM 2 ENABLE ENABLE U22:E DS26C31TM 82.5 82.5 GROUP A ENABLE ENABLE U23:E ENABLE ENABLE U1:A U6:E DS26C31TM PDM_A3...
  • Page 177 # MODULE U1:B 1000 #MODULE_ENABLE- ENABLE - 10.0K 82.5 82.5 33.2K MODULATION C146 33.2K B+_SAMPLE DO NOT CONNECT PIN 76 33.2K ON BACKPLANE BOARD 1.00M 1.00M 1.00M 28.7K ACS756KCA-050B-PFF 1.00M VOUT PA_VOLTS_SAMPLE 22.1 0.15 CR19 1.00M 0.15 CSD10060A 1.00M 1.00M 1.00M 28.7K 1.00M...
  • Page 178 10.0K # RESET - RESET #MODULE_ENABLE- U21:E FROM SHEET 1 INT1 TLV2374ID XTAL2 3320 10-14MHz 18pF AIN1 XTAL1 10.0K 18pF +15V 3320 R102 OVER CURRENT TEST AIN0 10.0K #MOD_DRIVE_ENABLE+ CR10 10.0K 0.01 27.4K 1N4448HWS 10.0K DC_CURRENT IRLL110 ADC0 PB.1 +15V 100K SHEET 2 +15V...
  • Page 179 Section 2, “Parts Lists” on page 2-1. Follow the family tree branches to the block that contains the desired reference designation and Nautel nomenclature (e.g., NAPA34A Modulator/Power Amplifier PWB ). Note the reference designations and Nautel nomenclatures of all higher assemblies in the path.
  • Page 180 Then, repeat this procedure until the desired part or assembly is found. Table 5.1: List of Mechanical Drawings Figure # Title MD-1 NX50 Transmitter (Front View) MD-2 NX50 Transmitter (Rear View) MD-3 NAH57C/01 RF Combiner Back Plane MD-4...
  • Page 181 RF CURRENT PROBE FAN TRAY ASSEMBLIES (A42) (A35-A39) PDM DRIVE DISTRIBUTION ASSEMBLY (A8) B+ DISTRIBUTION ASSEMBLY (A9) FRONT DOOR (A40), INNER & OUTER SIDE PANELS and TOP REMOVED FOR CLARITY Figure MD-1: NX50 Transmitter (Front View) Issue 6.0 2019-04-01 MD-1...
  • Page 182 (A7) are mounted on the underside of grill FUSE & MOV B+ DISTRIBUTION ASSEMBLY (A45) ASSEMBLY (A9) STATION REFERENCE GROUND REAR DOOR, INNER & OUTER SIDE PANELS and TOP REMOVED FOR CLARITY Figure MD-2: NX50 Transmitter (Rear View) Issue 6.0 2019-04-01 MD-2...
  • Page 183 Power Module Interface PWB A2 & A3 Transformer Assemblies Figure MD-3: NAH57C/01 RF Combiner Back Plane Issue 6.0 2019-04-01 MD-3...
  • Page 184 Figure MD-4: NAPI95A/01 Power Module Interface PWB Issue 6.0 2019-04-01 MD-4...
  • Page 185 Control/ Interface PWB Remote Interface PWB USB Audio Interface PWB (optional) Exgine PWB (optional) GPS Sync PWB (optional) Digital AM Digital AM Exciter PWB (A) Exciter PWB (B) Figure MD-5: NAE96C/01 Control/Exciter Panel Issue 6.0 2019-04-01 MD-5...
  • Page 186 (LOWER) FILTER SERIAL +15V +15V RACK DISTRIBUTION STREAMING BUS R145 R361 RF MONITOR 10 MHz SYNC (TO AUI) (UPPER) C122 COMBINER SYSTEM INTERLOCK (TO AUI) CR80 SAMPLE CONTROL INHIBIT C134 R150 C168 AES 2 AES 1 BALANCED ANALOG AUDIO CR15 CR77 RF MONITOR R122...
  • Page 187 J2-19 DIGITAL AM EXCITER NAPE78 SER. TP14 -15V TP10 C100 C120 C132 TP15 +15V TP13 C218 C101 +5V-A C118 C131 C212 C185 C202 C153 C190 C213 C186 C203 C159 C191 C219 C187 C204 +1.8V C209 TP12 C154 C192 +5V-D C128 +3.3V-A C140 TP11...
  • Page 188 Figure MD-8: NAPI106 Remote Interface PWB Issue 6.0 2019-04-01 MD-8...
  • Page 189 LOCK ACQUIRE UNLOCK +3.3V 1PPS 1 kHz +3.3V 10MHz TP10 GPS SYNC NAPX46 SER. 1PPS M2130004 V3 Figure MD-9: NAPX46 GPS Sync PWB (Optional) Issue 6.0 2019-04-01 MD-9...
  • Page 190 USB AUDIO INTERFACE NAPI151 SER. M2060292 V1 Figure MD-10: NAPI151 USB Audio Interface PWB (Optional) Issue 6.0 2019-04-01 MD-10...
  • Page 191 POWER SUPPLY NEXT RACK CONTROL/INTERFACE C147 TP29 1 2 3 4 5 6 7 8 RT21 TP27 R195 R197 RT17 RT18 C159 C160 OPEN R193 R152 R188 C146 R154 TP65 TP66 R203 R180 R135 R132 TP54 TP57 TP52 TP53 R182 C121 TP26 TP5 TP8...
  • Page 192 Figure MD-12: NAPI98 RF Drive Distribution PWB Issue 6.0 2019-04-01 MD-12...
  • Page 193 (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (LOWER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) (UPPER) C100 C101 C102...
  • Page 194 Rear View Front View Figure MD-14: NAX243B/01 B+ Distribution Assembly Issue 6.0 2019-04-01 MD-14...
  • Page 195 MODULATOR / POWER AMPLIFIER PWB CUTAWAY FROM A1 TO SHOW LOCATION / ORIENTATION FRONT VIEW OF FETS Q7 TO Q10 Figure MD-15: NAP39C RF Power Module Issue 6.0 2019-04-01 MD-15...
  • Page 196 R115 CR13 CR11 C114 CAUTION! CR38 HIGH VOLTAGE PRESENT ON THIS ASSEMBLY C108 C100 R105 R108 R110 R100 MODULATOR/POWER AMPLIFIER CR14 R126 R128 NAPA34 R112 SER. C137 R106 C106 R109 C107 C138 CR12 C102 CR18 R116 CR39 C140 C101 R111 C139 C118 C119...
  • Page 197 CABLE 2 CABLE 1 207-1150-03 MCH02 VA REAR Figure MD-17: NAPA34C Modulator/Power Amplifier PWB (Rear View) Issue 6.0 2019-04-01 MD-17...
  • Page 198 Figure MD-18: Fan Tray Assembly (207-8133) Issue 6.0 2019-04-01 MD-18...
  • Page 199 REAR VIEW WITH FILTER PANEL VOLTAGE PROBE REMOVED FOR CLARITY Figure MD-19: Voltage Probe (207-6111-01) Issue 6.0 2019-04-01 MD-19...
  • Page 200 Rear View Front View Figure MD-20: Current Probe (207-6213-10) Issue 6.0 2019-04-01 MD-20...
  • Page 201 A1 DETAIL Figure MD-21: NAFP106B/01 Directional Coupler Issue 6.0 2019-04-01 MD-21...
  • Page 202 NX50 Troubleshooting Manual List of terms Section 6: List of terms This section defines some of the terms that are used in Nautel documentation. Analog to Digital Converter. ADC. Audio Engineering Society/European Broadcasting Union (AES/EBU) is the name AES-EBU. of a digital audio transfer standard. The AES/EBU digital interface is usually implemented using 3-pin XLR connectors (the same type connector used in professional microphones).
  • Page 203 Preset. time-of-day and date basis. Exciters can be configured on a preset for a specific operating mode (for example, Exciter A - conventional AM, and Exciter B - IBOC). The NX50 allows you to pre-program multiple presets. A complete loss of RF output power, caused by any one of a variety of faults, Shutback.
  • Page 205 Phone: +1.902.823.3900 or Fax: +1.902.823.3183 Nautel Inc. 201 Target Industrial Circle Bangor, Maine USA 04401 Phone: +1.207.947.8200 Fax: +1.207.947.3693 Customer Service (24-hour support) +1.877.628.8353 (Canada & USA only) +1.902.823.5100 (International) Email: support@nautel.com Web: www.nautel.com © Copyright 2019 NAUTEL. All rights reserved.

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