Keysight N1911A/1912A P-Series Power Meters Service Guide
Notices © Keysight Technologies 2006 - 2014 Warranty No part of this manual may be reproduced in any form or by any means (including electronic storage and retrieval or translation into a foreign language) without prior agreement and written consent from Keysight Technologies as governed by United States and international copyright laws. The material contained in this document is provided “as is,” and is subject to being changed, without notice, in future editions.
Certification Keysight Technologies certifies that this product met its published specifications at the time of shipment from the factory.
Equipment Operation Warnings and Cautions This guide uses warnings and cautions to denote hazards. WA R N I N G A WARNING notice denotes a hazard. It calls attention to an operating procedure, practice, or the like that, if not correctly performed or adhered to, could result in personal injury or loss of life. Do not proceed beyond a WARNING notice until the indicated conditions are fully understood and met. CAUTION A CAUTION notice denotes a hazard.
General Safety Considerations The following general safety precautions must be observed during all phases of operation of this instrument. Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design, manufacture, and intended use of the instrument. Keysight Technologies assumes no liability for the customer’s failure to comply with these requirements.
Safety Symbols The following symbol on the instrument and in the documentation indicates precautions that must be taken to maintain safe operation of the instrument. Caution, risk of danger. The Instruction Documentation Symbol. The product is marked with this symbol when it is necessary for the user to refer to the instructions in the supplied documentation. Alternating current (AC). This symbol indicates the operating switch for ‘Stand-by’ mode.
PROTECTIVE CONDUCTOR TERMINAL. Frame or chasis TERMINAL. Equipotentiality. On (Supply). Off (Supply). Equipment protected throughout by DOUBLE INSULATION or REINFORCED INSULATION. Caution, risk of electric shock. Caution, hot surface. In position of bi-stable push control.
Out position of bi-stable push control.
Environmental Conditions This instrument is designed for indoor use. The table below shows the general environmental requirements for this instrument.
Regulatory Markings x The CE mark is a registered trademark of the European Community. This CE mark shows that the product complies with all the relevant European Legal Directives. The C-tick mark is a registered trademark of the Spectrum Management Agency of Australia. This signifies compliance with the Australia EMC Framework regulations under the terms of the Radio Communication Act of 1992. ICES/NMB-001 indicates that this ISM device complies with the Canadian ICES-001.
In This Guide ... 1 Specifications Chapter 1 lists the power meter’s specifications and describes how to interpret these specifications. 2 Performance Tests Chapter 2 contains procedures which allow you to test the power meter’s electrical performance to it’s specifications. 3 Adjustments Chapter 3 contains checks and adjustments that ensure proper performance of the power meter. 4 Theory of Operation Chapter 4 describes how each of the power meter’s individual assemblies operate.
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Contents Notices ii Certification iii Limitation of Warranty iii Exclusive Remedies iii Equipment Operation iv General Safety Considerations v Safety Symbols vi Environmental Conditions ix Regulatory Information ix Regulatory Markings x In This Guide ...
Linearity (Average Path) 32 Linearity (Peak Path) 33 Rise/Fall Time (Peak Path) 34 3 Adjustments Introduction 38 Power Reference Level Adjustment 39 4 Theory of Operation PPMC Assembly 42 Main Board Assembly 43 DAP Assembly 44 Calibrator Assembly 45 Front Panel Assembly 46 PSU Assembly 47 5 Troubleshooting Guide Introduction 50 Power-Up Problems 51 Instrument Self-Test 52 Extended Self-Test 54 Performance Test 55 Power Reference Level Adjustment Problems 56 Communication Interface Failures 57 Additional
Front Panel Disassembly Instructions 98 Front Panel Reassembly Instructions 103 Additional Repair Notes 108 Replacing the PPMC Assembly 110 Replacing the Calibrator Semi-Rigid/Split Ferrite 111 7 Contacting Keysight Technologies Introduction 114 Before Calling Keysight Technologies 115 Check the Basics 116 Instrument Serial Numbers 117 Keysight Sales and Service Offices 118 Returning Your Power Meter for Service 119 Useful Web Pages 120 N1911A/1912A P-Series Power Meters Service Guide xv
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List of Figures Figure 2-1 1 mW Power Reference Level Test Setup Connection Diagram 23 Figure 2-2 System Calibration Connection Diagram 26 Figure 2-3 Output SWR Test Setup - Open Connection Diagram 26 Figure 2-4 Output SWR Test Setup - Load Connection Diagram 26 Figure 2-5 Time Base Test Setup Connection Diagram 28 Figure 2-6 Rise/Fall Time Test Setup Connection Diagram 34 N1911A/1912A P-Series Power Meters Service Guide xvii
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N1911A/1912A P-Series Power Meters Service Guide 1 Specifications Introduction 2 Specification Definitions 3 General Features 5 P-Series Power Meter and Sensor 6 P-Series Power Meter Specifications 8 P-Series Wideband Power Sensor Specifications 10 Sensor Calibration Uncertainty9 11 1 mW Power Reference 12 System Specifications and Characteristics 15 Characteristics Peak Flatness 16 This chapter lists the power meter’s specifications and describes how to interpret these specifications.
1 Specifications Introduction This chapter details the power meter’s specifications and supplemental characteristics Specifications describe the warranted performance and apply after a 30 minute warm- up. These specifications are valid over the power meter’s operating and environmental range unless otherwise stated and after performing a zero and calibration.
Specifications 1 Specification Definitions There are two types of product specifications: Warranted specifications are specifications which are covered by the product warranty and apply over 0 to 55½ oC unless otherwise noted. Warranted specifications include measurement uncertainty calculated with a 95 % confidence. Characteristic specifications are specifications that are not warranted. They describe product performance that is useful in the application of the product.
1 Specifications Conditions The power meter and sensor will meet its specifications when: • stored for a minimum of two hours at a stable temperature within the operating temperature range, and turned on for at least 30 minutes • the power meter and sensor are within their recommended calibration period, and • used in accordance to the information provided in the user’s guide.
Specifications 1 General Features Number of channels N1911A P-Series power meter, single channel N1912A P-Series power meter, dual channel Frequency range N1921A P-Series wideband power sensor, 50 MHz to 18 GHz N1922A P-Series wideband power sensor, 50 MHz to 40 GHz Measurements Average, peak and peak-to-average ratio power measurements are provided with free-run or time gate definition.
1 Specifications P-Series Power Meter and Sensor Key System Specifications and Characteristics Maximum sampling rate 100 Msamples/sec, continuous sampling Video bandwidth ≥ 30 MHz Single shot bandwidth ≥ 30 MHz Rise time and fall time ≤ 13 ns (for frequencies ≥ 500 MHz)3 , see Figure 1-1 Minimum pulse width 50 ns4 Overshoot ≤ 5 %3 Average power measurement accuracy N1921A: ≤ ± 0.2 dB or ± 4.5 %5 N1922A: ≤ ± 0.3 dB or ± 6.
Specifications 1 Figure 1-1 Measured rise time percentage error versus signal under test rise time Although the rise time specification is ≤ 13 ns, this does not mean that the P- Series meters and sensors combination can accurately measure a signal with a known rise time of 13 ns.
1 Specifications P-Series Power Meter Specifications Meter uncertainty Instrumentation linearity ± 0.8 % Timbebase Timebase range 2 ns to 100 msec/div Accuracy ± 10 ppm Jitter ≤ 1ns Trigger Internal trigger Range –20 to +20 dBm Resolution 0.1 dB Level accuracy ± 0.5 dB Latency 6 160 ns ± 10 ns ≤ 5 ns rms Jitter External TTL trigger input High > 2.4 V Low Latency < 0.
Specifications 1 Trigger delay Delay range ± 1.0 s, maximum Delay resolution 1% of delay setting, 10 ns maximum Trigger hold-off Range 1 μs to 400 ns Resolution 1% of selected value (to a minimum of 10 ns) Trigger level threshold hysteresis Range ± 3 dB Resolution 0.05 dB 6 Internal trigger latency is defined as the delay between the applied RF crossing the trigger level and the meter switching into the triggered state.
1 Specifications P-Series Wideband Power Sensor Specifications The P- Series wideband power sensors are designed for use with the P- Series power sensor only. Sensor model Frequency range Dynamic range Damage level Connector type N1921A 50 MHz to 18 GHz -35 dBm to +20 dBm (500 MHz) +23 dBm (average Type N (m) power); -30 dBm to +20 +30 dBm (<1μs dBm (50 MHz to 500 duration)(peak MHz) power) N1922A 50 MHz to 40 GHz 35 dBm to +20 dBm (500 MHz) 2.
Specifications 1 Sensor Calibration Uncertainty9 Definition: Uncertainty resulting from non- linearity in the sensor detection and correction process. This can be considered as a combination of traditional linearity, cal factor and temperature specifications and the uncertainty associated with the internal calibration process. 9 Beyond 70 % Humidity, and additional 0.6 % should be added to these values. Frequency band N1921A N1922A 50 MHz to 500 MHz 4.5 % 4.3 % 500 MHz to 1 GHz 4.0 % 4.
1 Specifications 1 mW Power Reference NOTE The 1mW power reference is provided for calibration of E-Series, 8480 Series and N8480 Series sensors. The P-Series sensors are automatically calibrated do not need this reference calibration. Power output 1.00 mW (0.0 dBm). Factory set ± 0.4 % traceable to the National Physical Laborator (NPL) UK Accuracy (over 2 years) ± 1.2 % (0 to 55 oC) ± 0.4 % (25 ± 10 oC) Frequency 50 MHz nominal SWR 1.08 (0 to 55 oC) 1.
Specifications 1 Remote Programming Interface GPIB interface operates to IEEE 488.2 and IEC65 10/100 BaseT LAN interface USB 2.
1 Specifications Physical Characteristics Dimensions The following dimensions exclude front and rear panel protrusions: 88.5 mm H x 212.6 mm W x 348.3 mm D (3.5 in x 8.5 in x 13.7 in) ≤ 3.5 kg (7.7 lb) approximate N1911A Net weight N1912A Shipping weigh N1911A N1912A ≤ 3.7 kg (8.1 lb) approximate ≤ 7.9 kg (17.4 lb) approximate ≤ 8.0 kg (17.6 lb) approximate Environmental Conditions General Complies with the requirement of the EMC Directive 89/336/EEC.
Specifications 1 System Specifications and Characteristics The video bandwidth in the meter can be set to High, Medium, Low and Off. The video bandwidths stated in the table below are not the 3 dB bandwidths, as the video bandwidths are corrected for optimal flatness (except the Off filter). Refer to Figure 1- 2 for information on the flatness response.
1 Specifications Characteristics Peak Flatness The peak flatness is the flatness of a peak- to- average ratio measurement for various tone- separations for an equal magnitude two- tone RF input. Figure 1- 2 refers to the relative error in peak- to- average ratio measurements as the tone separation is varied. The measurements were performed at –10 dBm with power sensors with 1.5 m cable lengths.
Specifications 1 Noise and drift Sensor Model Zeroing Zero set < 500 MHz N1921A/ N1922A No RF on input Noise per sample Measurement noise (Free run)13 100 nW 2 μW 50 nW > 500 MHz 200 nW 550 nW RF present Zero drift12 200 nW 12 Within 1 hour after a zero, at a constant temperature, after 24 hour warm up of the power meter. This component can be disregarded with Auto zero mode set to ON.
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N1911A/1912A P-Series Power Meters Service Guide 2 Performance Tests Introduction 20 Complete Equipment List 21 1 mW Power Reference Level Test 23 Output Standing Wave Ratio (SWR) Test 25 Time Base Frequency Accuracy 28 Zero Set (Average Path) 30 Zero Set (Peak Path) 31 Linearity (Average Path) 32 Linearity (Peak Path) 33 Rise/Fall Time (Peak Path) 34 This chapter contains procedures which allow you to test the power meter’s electrical performance to it’s specifications.
2 Performance Tests Introduction The performance tests described in this chapter test the power meter’s electrical performance against the specifications detailed in Chapter 1. They are used for incoming inspection, the calibration cycle (also called periodic maintenance), or after repairs have been made.
Performance Tests 2 Complete Equipment List Instrument Critical Specifications Recommended Keysight Model Number Alternative Keysight Model Number N3383A N3381A N3382A 8753ES/ET Frequency: 10 MHz Gate Time: 10 seconds 53132A 53131A Dual channel Absolute Accuracy: +0.5 % E4419B E4419A Analyzers Network analyzer Counters Universal counter Meters Power meter Power sensor 2 required Power sensor Power Reference Accuracy: +0.
2 Performance Tests 81130A Pulse/Data generator 81131A Output modules required Power splitter required Frequency: DC to 6 GHz Insertion Loss: 6 to 7 dB, ≤ 3 GHz SWR: < 1.1 10 MHz to 2 GHz < 1.
Performance Tests 2 1 mW Power Reference Level Test Description The 1 mW power reference is used for the calibration of 8480 Series, N8480 Series and E- Series power sensors, and is traceable to national standards. This test uses an 8482A power sensor to transfer the power measured on an accurately calibrated E4419B or E4417A power meter to the DUT reference. Equipment • Required test equipment: 1 unit of E4419B or E4417A dual channel power meter, 1 unit of 8482A power sensor.
2 Performance Tests Test Method 1 Enter the recorded measurement uncertainty of the E4419B or E4417A 1 mW power reference 2 Using the E4419B or E4417A power meter and the 8482A sensor, measure the 1mW power reference of the E4419B or E4417A 3 Using the E4419B or E4417A power meter and the 8482A sensor, measure the 1 mW power reference of the DUT 4 Using all of these values, the N7832A software will calculate the power reference level of the DUT NOTE • The 1 mW reference of the E4419B or E4417A power met
Performance Tests 2 Output Standing Wave Ratio (SWR) Test Description Connector mismatch is the largest single contributor to measurement uncertainty, so this specification must be warranted to provide assurance of instrument accuracy. The 1 mW power reference level test must be carried out prior to this test, as the VSWR specification is only valid at 1 mW.
2 Performance Tests Load Port TYPE N MALE PORT 20 dB ATTENUATOR POWER METER POWER SPLITTERS POWER SENSOR Ch A CH B 30 dB ATTENUATOR Figure 2-2 System Calibration Connection Diagram P-SERIES POWER METER POWER METER Ch A 20 dB ATTENUATOR POWER SENSOR Load Port TYPE-N MALE OPEN Figure 2-3 Output SWR Test Setup - Open Connection Diagram P-SERIES POWER METER POWER METER Ch A 20 dB ATTENUATOR POWER SENSOR Load Port TYPE-N MALE LOAD Figure 2-4 Output SWR Test Setup - Load Connection Diagram 2
Performance Tests NOTE 2 For rear panel options, the connections will differ from the illustration shown here. Refer to the connector identification markings on the rear panel for further details Test Method 1 Obtain the S11 parameter of the calibration system. 2 Connect the measurement system to the calibration system and obtain its S21 (load) & S21 (open) parameters.
2 Performance Tests Time Base Frequency Accuracy Description The accuracy of the 100 MHz sample clock determines the accuracy of all measurements that are based on samples taken over time. This test measures the time base by dividing the sample clock by 10 (within the meter) and feeding it out of the trigger output connector, where it can be directly measured by a frequency counter.
Performance Tests 2 Test Method 1 Enable the path that routes the time base signal to the trigger output connector. 2 Using the 53132A, measure the frequency of the signal at the trigger output connector. NOTE • This test can be configured manually via the command SERV:BIST:TBAS:STAT ON, which enables the 10 MHz feed to the trigger output connector (refer to the programming guide for further details on the use of this command).
2 Performance Tests Zero Set (Average Path) Description Zero set is defined as the amount of residual offset error that is present following a zero operation. This offset error is caused by contamination from several sources, including circuit noise. This test measures the effectiveness of zero set by performing 15 back- to- back zero operations of the average path (with no sensor attached), after which the standard deviation of the results is calculated and returned as the measured value.
Performance Tests 2 Zero Set (Peak Path) Description Zero set is defined as the amount of residual offset error that is present following a zero operation. This offset error is caused by contamination from several sources, including circuit noise. This test measures the effectiveness of zero set by performing 15 back- to- back zero operations of the peak path (with no sensor attached), after which the standard deviation of the results is calculated and returned as the measured value.
2 Performance Tests Linearity (Average Path) Description Linearity over the full input voltage range of the measurement path is warranted to provide assurance of instrument accuracy. This test measures linearity by using a calibration DAC and a calibration ADC (built into the DUT) to stimulate and compare performance of the average path against the measurement ADC, returning the worst case percentage error.
Performance Tests 2 Linearity (Peak Path) Description Linearity over the full input voltage range of the measurement path is warranted to provide assurance of instrument accuracy. This test measures linearity by using a calibration DAC and a calibration ADC (built into the DUT) to stimulate and compare performance of the peak path against the measurement ADC, returning the worst case percentage error.
2 Performance Tests Rise/Fall Time (Peak Path) Description The rise and fall time performance of the instrument path has to be quantified accurately. The 81130A pulse generator is used to supply the appropriate pulse with defined rise and fall time. The instrument measures and processes the known signal which is then compared with defined acceptance limits. Overshoot, settling time and pulse recovery are also characterized.
Performance Tests NOTE 2 For rear panel options, the connections will differ from the illustration shown here. Refer to the connector identification markings on the rear panel for further details Test Method 1 Capture a train of 10 pulses with very fast rise/fall times. 2 Combine the sample data to create an equivalent pulse with 10 unit of the sample resolution of the DUT.
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N1911A/1912A P-Series Power Meters Service Guide 3 Adjustments Introduction 38 Power Reference Level Adjustment 39 This chapter contains checks and adjustments that ensure proper performance of the power meter.
3 Adjustments Introduction Attempts to correct the power reference level if the performance test has failed. Power reference level is controlled by the coarse and fine settings of a digital potentiometer. Adjustment of the coarse and fine settings can only be carried out via remote commands. Adjustment can be carried out without having to remove the outer covers from the DUT.
Adjustments 3 Power Reference Level Adjustment Equipment • As per the test equipment list for the power reference level performance test Test Method 1 Set: Coarse = 834, Fine = 550 2 Measure power ref. level as per the performance test: a If the result is > 1 mW, the increment COARSE by 1 b If the result is < 1 mW, the decrement COARSE by 1 3 Repeat step 2 until the result crosses the 1 mW boundary (in either direction) 4 Measure power ref.
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N1911A/1912A P-Series Power Meters Service Guide 4 Theory of Operation PPMC Assembly 42 Main Board Assembly 43 DAP Assembly 44 Calibrator Assembly 45 Front Panel Assembly 46 PSU Assembly 47 This chapter describes how each of the power meter’s individual assemblies operate.
4 Theory of Operation PPMC Assembly Purpose • Provides the main processor and memory for the power meter • Provides external interfaces for LAN and USB • Stores the power meter firmware in flash EEPROM • Stores the power meter serial number and option data Inputs • Power supplies [from PSU, via main board] • Control and data lines [from main board, DAP(s), and front panel] • LAN/ USB communications [from external equipment] • GPIB communications [from external equipment, via main board] Outputs • Contro
Theory of Operation 4 Main Board Assembly Purpose • Provides the average measurement path(s) • Provides the peak measurement path(s) to the DAP(s) • Provides external trigger input/ output and recorder output(s) • Provides the driver and the LVDS serialiser for the LCD display • Provides signal routing between the PPMC, DAP(s), and front panel Inputs • Power supplies [from PSU] • Sensed power level(s) [from sensor flexi(s)] • Trigger input [from external equipment] • Control, address, and data lines [fro
4 Theory of Operation DAP Assembly Purpose • Provides data acquisition and processing for the peak measurement path of a channel Inputs • Power supplies [from PSU, via main board] • Unprocessed peak path measurement samples [from main board] • Control, address, and data lines [from PPMC] Outputs • Processed peak path measurement data [to PPMC, via main board] • Control and data lines [to PPMC, via main board] 44 N1911A/1912A P-Series Power Meters Service Guide
Theory of Operation 4 Calibrator Assembly Purpose • Provides a 1 mW (0 dBm) power reference level at 50 MHz Inputs • Power supplies [from PSU, via main board] • Control, address, and data lines [from PPMC] Outputs • 1 mW (0 dBm) power reference [to external equipment] • Control and data lines [to PPMC, via main board] N1911A/1912A P-Series Power Meters Service Guide 45
4 Theory of Operation Front Panel Assembly Purpose • Provides a keyboard as the manual user interface • Provides an LCD display to assist with manual setups and measurements • Provides mounting for the sensor and power reference connectors (option 101) Inputs • Power supplies [from PSU, via main board] • Front panel control interface [from the PPMC LVDS LCD control lines, via main board] Outputs • Keypress data [to PPMC, via main board] • Information on the LCD display • Control and data lines [to PPMC,
Theory of Operation 4 PSU Assembly Purpose: • Provides various DC power supplies Inputs: • 100 Vac~ 240 Vac, 50 Hz~ 60 Hz, 150 VA Max [from an external source] • Control lines [from front panel, via main board] Outputs: • +12 Vdc [to main board] • +5 Vdc ]to main board] • - 5 Vdc [to main board] • - 12 Vdc [to main board] N1911A/1912A P-Series Power Meters Service Guide 47
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N1911A/1912A P-Series Power Meters Service Guide 5 Troubleshooting Guide Introduction 50 Power-Up Problems 51 Instrument Self-Test 52 Extended Self-Test 54 Performance Test 55 Power Reference Level Adjustment Problems 56 Communication Interface Failures 57 Additional Diagnostic Tests 58 This chapter contains troubleshooting flow charts designed to isolate faults in the Rmt I/O, GP- IB and RS232/422 interface ports.
5 Troubleshooting Guide Introduction This chapter enables qualified service personnel to diagnose suspected faults with the power meter Rmt I/O (Remote Input/Output) signal lines and RS232/422 serial port. If there is a problem when attempting to use the RS232/422 serial interface or the remote I/O functions, consult the user’s guide and confirm that all the user setups are correct before proceeding with the following fault finding flowcharts.
Troubleshooting Guide 5 Power-Up Problems Basic External Checks • Check the mains power source is live • Check the mains fuse is operational • Check the mains cable for any obvious damage • Check the line module fuse in the instrument is operational Basic Internal Checks • Check/reseat the cable between the line module and the PSU • Check/reseat the cable between the PSU and the main board • Green LED DS1: If this is off, then the PSU may be faulty • Green LED DS4: This should come on when the power butt
5 Troubleshooting Guide Instrument Self-Test Instrument Purpose Debug Tips Test point voltages Checks that all of the supply voltages are present Replace the PSU to see if this PSU (low probability) clears the faults Main board (high probability) Calibrator Verifies that the calibrator is working Check/reseat that cable Calibrator assembly (high between the Calibrator probability) Assembly and the Main Board Main board (low probability) Attempt to adjust the 1 mW Power Reference Level (Note: This
Troubleshooting Guide ChB peak path Verifies that the peak path of channel B is working (Note: This does not prove that the peak path meets its specifications) ChB CW path Verifies that the average path of channel B is working Replace the DAP assembly for channel B to see if this clears the fault DAP assembly, channel B (low probability) Not applicable Main board 5 Main board (high probability) (Note: This does not prove that the average path meets its specifications) ChB DAP check Executes an i
5 Troubleshooting Guide Extended Self-Test Instrument Purpose Keyboard Verifies the operation of every Not applicable key (apart from the power button) Front panel (defective keymat or key flex circuit) Bitmap display Verifies that all pixels in the display can be illuminated in various colors Front panel (defective display, display interface board, or inverter board) Time base Provides a means to measure Check that the BNC cable time base frequency accuracy being used is not damaged Check that t
Troubleshooting Guide 5 Performance Test Type of Failures Debug Tips Possible Faults 1 mW power reference level failures Attempt to adjust the 1 mW power reference level Calibrator assembly (high probability) Main board (low probability) VSWR failures Not applicable Calibrator assembly Time base frequency accuracy failures Check that the BNC cable being Main board used is not damaged Check that the BNC is connected to ‘Trig Out’, not ‘Trig In’ Zero set (average Path) failures Not applicable Ma
5 Troubleshooting Guide Power Reference Level Adjustment Problems Possible Faults • Calibrator assembly (high probability) • Main board (low probability) 56 N1911A/1912A P-Series Power Meters Service Guide
Troubleshooting Guide 5 Communication Interface Failures Type of Communication Debug Tips Possible Faults GPIB communication Check/reseat the ribbon cable connecting the PPMC to the main board Ribbon cable (low probability) PPMC assembly (low probability) Main board (high probability) LAN/USB communication Check visually to see whether or PPMC assembly not the connector is obstructed/damaged N1911A/1912A P-Series Power Meters Service Guide 57
5 Troubleshooting Guide Additional Diagnostic Tests Type of Functionality Reason Recommended Test Method USB/LAN functionality The N7832A software only tests functionality over GPIB Check the DUT responds when PPMC assembly *RST is sent to it via the USB/LAN interfaces Sensor functionality The N7832A software does not prove both paths of the sensor flex assembly Connect an E4412A sensor to Sensor flex assembly the DUT and ensure it can be zeroed/calibrated 58 Possible Faults N1911A/1912A P-Seri
N1911A/1912A P-Series Power Meters Service Guide 6 Repair Guide Introduction 60 Replaceable Parts 61 Front Panel Assembly 61 Main Board Assembly 69 PPMC (Processor PCI Mezzanine) Assembly 70 DAP (Digital Acquisition & Processing) Assembly 71 PSU (Power Supply Unit) 72 Rear Panel Assembly 73 Additional Spare Parts 76 Calibrator Assembly 77 Improved calibrator assembly 78 Outer Housing Components 79 Sundries 81 Tools Required 82 Required Torque Values for Fasteners 83 Disassembly Instructions 84 Reassembly I
6 Repair Guide Introduction This chapter contains details of some of the higher level components and assemblies which can be ordered from Keysight Technologies. It also details how to assemble and disassemble the power meter for repair.
Repair Guide 6 Replaceable Parts Front Panel Assembly Main Assembly The standard P- Series power meter has the reference calibrator at the front panel. Option is available to move the reference calibrator to rear panel.
6 Repair Guide Customization Details The standard P- Series power meters have the input sensor connector(s) and reference calibrator connector on the front panel. Option 003 is available to move the input sensor connector(s) and reference calibrator connector to the rear panel. Below are the customization details on front panel assembly.
Repair Guide 6 Customization Parts Keysight Part Number Description N1912-61806 Sensor flex assembly Visual Note: • The same assembly is used for all four sensor positions • The kit includes a spacer, required for fitting the flex to the rear panel • The sensor flex assembly is supplied straight, and so it must be folded to match the assembly being replaced (see “Additional Repair Notes” on page 108) N1912-21003 Calibrator plug N1912-21005 Front panel plug (small) N1912- 21004 N1912- 21005 N191
6 Repair Guide Keysight Part Number Description N1912-00025 Blank front panel dress label N1912-00026 N1911A front panel dress label N1912-00027 N1912A front panel dress label Visual N1912-00025 N1912-00026 N1912-00027 N1911-80001 N1911A nameplate N1912-80003 N1912A nameplate N1911-80001 N1912-80003 64 N1911A/1912A P-Series Power Meters Service Guide
Repair Guide 6 Replaceable Parts Keysight Part Number Description N1912-40003 Front panel sub-frame Visual Note: • This front panel sub-frame is used on all variants of the front panel assembly N1912-40002 Display support molding Note: • This display support molding is used on all variants of the front panel assembly N1912-40001 Keymat Note: • This keymat is used on all variants of the front panel assembly N1911A/1912A P-Series Power Meters Service Guide 65
6 Repair Guide Keysight Part Number Description N1912-66502 Key flex circuit Visual Note: • This key flex circuit is used on all variants of the front panel assembly N1912-20005 EMI shielded window Note: • This EMI shielded window is used on all variants of the front panel assembly N1912-00002 EMI Screen Note: • This EMI screen is used on all variants of the front panel assembly 66 N1911A/1912A P-Series Power Meters Service Guide
Repair Guide Keysight Part Number Description 2090-0825 Display 6 Visual Note: • This display is used on all variants of the front panel assembly Front View Rear View N1912-60002 Display interface board Note: • This display interface board is used on all variants of the front panel assembly N1911A/1912A P-Series Power Meters Service Guide 67
6 Repair Guide Keysight Part Number Description 0950-4111 Inverter board Visual Note: • This inverter board is used on all variants of the front panel assembly N1912-61002 Backlight cable assembly Note: • This backlight cable assembly is used on all variants of the front panel assembly N1912-00038 Split washer Note: • This split washer is used on all variants of the front panel assembly 68 N1911A/1912A P-Series Power Meters Service Guide
Repair Guide 6 Main Board Assembly Keysight Part Number Description N1911-61801 (non-video output option) N1911A main board assembly [new] N1911-66501 (video output option) N1911A main board assembly – video output option (Option H01) N1912-61801 (non-video output option) N1912A main board assembly [new] N1912-66501 (video output option) N1912A main board assembly – video output option (Option H01) Visual Note: • Refurbished main boards are not available • The part number for the lithium mangan
6 Repair Guide PPMC (Processor PCI Mezzanine) Assembly Keysight Part Number Description N1911-66500 (single-channel PPMC PCA) PPMC PCA N1912-66500 (dual-channel PPMC PCA) Visual Note: • The same assembly is used for both N1911A and N1912A models • N1911-66500 (single-channel PPMC PCA) comes pre-programmed with N1911A firmware • N1912-66500 (dual-channel PPMC PCA) comes pre-programmed with N1912A firmware • Refurbished PPMC assemblies are not available • The PPMC assembly must be programmed once it h
Repair Guide 6 DAP (Digital Acquisition & Processing) Assembly Keysight Part Number Description N1912-60004 Measurement board Visual Note: • The same assembly is used for both N1911A and N1912A models • Two identical DAP assemblies are fitted to the N1912A model • Refurbished DAP assemblies are not available Top/Bottom Views N1911A/1912A P-Series Power Meters Service Guide 71
6 Repair Guide PSU (Power Supply Unit) Keysight Part Number Description N1912-61808 Power supply assembly kit [new] Visual Note: • The same assembly is used for both N1911A and N1912A models • Refurbished PSUs are not available • Cables N4010-61846 and N4010- 61845 are supplied separately N401061846 N401061845 72 N1911A/1912A P-Series Power Meters Service Guide
Repair Guide 6 Rear Panel Assembly Main Assembly Keysight Part Number Description N1912-61007 Rear panel assembly [new] N1912-61031 Revised rear panel assembly [new] Visual Note: • The rear panel assembly must be customized to suit the hardware configuration of the unit being repaired • Refurbished rear panel assemblies are not available • Parts N1912-61007 and N1912- 61031 differ slightly with regards to the connector cutout positions • The revision of the main board can be used to help determine
6 Repair Guide Connector Option Details Part Number N1911A (front connectors option) 1 unit of sensor flex assembly 1 unit of N-Type connector 1 unit of lock washer 1 unit of hex nut 1 unit of washer 1 unit of rear panel plug (BNC) 1 unit of rear panel plug (Sensor) N1912-61806 E4418-20009 E4418-00016 2950-0132 3050-0916 6960-0081 6960-0024 N1912A (front connectors option) 1 unit of Recorder Output Cable 2 unit of rear panel plug (Sensor) 1 unit of rear panel plug (Calibrator) E4418-61015 6960-002
Repair Guide Keysight Part Number Description N1912-61806 Sensor flex assembly E4418-61015 Recorder output cable 6960-0081 Rear panel plug (BNC) 6960-0024 Rear panel plug (sensor) 6960-0178 Rear panel plug (calibrator) Visual (Two Views Shown For Each Part) 69600178 N1911A/1912A P-Series Power Meters Service Guide 6 69600024 69600081 75
6 Repair Guide Additional Spare Parts Keysight Part Number Description N1912-61036 Line module N4010-21025 Service connector cable 76 Visual N1911A/1912A P-Series Power Meters Service Guide
Repair Guide 6 Calibrator Assembly Keysight Part Number Description N1911-61001 Calibrator assembly (front connectors option). Visual For more information on the improved calibrator assembly, refer to “Improved calibrator assembly” on page 78.
6 Repair Guide Improved calibrator assembly The N1911A/N1912A calibrator assembly is improved with a new type- N calibrator connector for a better fit with the front panel assembly as shown in Figure 6- 1. The calibrator plug (N1912- 21003) will not be needed with the improved calibrator assembly. NOTE The N1911A/N1912A performance will not be affected with the improved calibrator assembly.
Repair Guide 6 Outer Housing Components Keysight Part Number Description 5041-7717 Clamshell (top) 5041-7718 Clamshell (bottom) N1912-61005 Fan assembly N1911A/1912A P-Series Power Meters Service Guide Visual 79
6 Repair Guide Keysight Part Number Description N1912-61025 Cable clamp 34401-86020 Bumper kit 34401-45021 Handle 80 Visual N1911A/1912A P-Series Power Meters Service Guide
Repair Guide 6 Sundries Keysight Part Number Description N1911-61004 Calibrator semi-rigid cable (rear option) N1912-80005 Split ferrite Note: • If the semi-rigid cable is replaced, then the split ferrite must be positioned correctly (see “Additional Repair Notes” on page 108) 2110-0957 Visual N1911-61004 (with N1912-80005) Line module fuse, 3.
6 Repair Guide Tools Required Keysight Part Number Description N1911-61004 • 3 unit of ¼” drive torque wrenches N1912-80005 Visual • 1 unit of calibrated to 2.37 Nm (21 lb-in) • 1 unit of calibrated to 1.02 Nm (9 lb-in) • 1 unit of calibrated to 0.68 Nm (6 lb-in) • 3 unit of torque screwdrivers • 1 unit of calibrated to 2.37 Nm (21 lb-in) • 1 unit of calibrated to 0.56 Nm (5 lb-in) • 1 unit of calibrated to 0.
Repair Guide 6 Required Torque Values for Fasteners Required tools and torque values for fasteners are listed below: Item Description/Default Range of Values 9/32” socket 0.68 Nm Special tooling kit (N1912-61807) 2.37 Nm Fit rear panel recorder output connectors 7/16” spanner 2.37 Nm Attach main board to clamshell T20 screwdriver 2.37 Nm Attach PPMC/DAP assemblies to main board T8 screwdriver 0.56 Nm Fit calibrator semi- rigid, both ends (Option 003) 5/16” spanner 1.
6 Repair Guide Disassembly Instructions The guidelines in this section describe the disassembly of the major assembling in the Keysight N1911A and N1912A power meters. Instructions Visual • This procedure focuses primarily on model N1912A, Option 101 (i. e. dual channel, with front panel sensor and power reference connectors) • Additional information is provided to assist in the disassembly of Option 003 units (i. e.
Repair Guide Instructions 6 Visual • Remove the top clamshell (Figure 6-3): Disconnect the mains power connector from the top clamshell. Disconnect the ribbon cable from the main board. Disconnect both earth spade connectors from the top clamshell. Remove top clamshell. Figure 6-3 • Remove the PSU safety cover (Figure 6-4): Use the T10 Torx screwdriver bit to remove the 4 screws attaching the PSU safety cover to the top clamshell. Lift and remove the safety cover.
6 Repair Guide Instructions Visual • Remove the PSU (Figure 6-5): Use the T10 Torx screwdriver bit to remove the 6 screws attaching the PSU to the top clamshell. Lift and remove the PSU.
Repair Guide Instructions • With reference to Figure 6-6 and Figure 6-7: • Lift and remove the cable clamp. • Disconnect the cable attaching the fan assembly to the main board. • Lift and remove the fan assembly • Disconnect the sensor RF connections from the main board. • Disconnect the sensor flex connection(s) from the main board. • Disconnect the calibrator cable connection from the main board. • Disconnect the analog recorder output connection(s) from the main board.
6 Repair Guide Instructions Visual • Disconnect the front panel cable (Figure 6-9): Depress both sides of theconnector holding the ribbon cable to eject it. Figure 6-9 • Disconnect the semi-rigid cable (Figure 6-10): Note: • This only applies to Option 003 units. Use the 5/16” spanner to disconnect the semi-rigid cable from the N-Type connector on the rear panel.
Repair Guide Instructions 6 Visual • Remove the front panel (Figure 6-11): Carefully lift and remove the front panel assembly. Figure 6-11 • Disconnect PPMC cables (Figure 6-6/Figure 6-7): Disconnect the service connector cable from the PPMC assembly. Disconnect the ribbon cable from the main board, whilst leaving it conected to the PPMC assembly.
6 Repair Guide Instructions Visual • Remove DAP/PPMC (Figure 6-12): Use the T8 Torx screwdriver bit to remove the screws attaching the DAP and PPMC assemblies to the main board. Carefully remove the PPMC assembly by lifting the end closest to the DAP assembly. Carefully remove each DAP assembly by lifting the end closest to the rear panel. Figure 6-12 • Remove the main board (Figure 6-13): Use the T20 Torx screwdriver bit to remove the 5 screws attaching the main board to the bottom clamshell.
Repair Guide Instructions 6 Visual • Remove the rear panel (Figure 6-14): Use the N1912-61807 special tooling kit to remove the asteners on the trigger connectors. Use the 9/32” Socket to remove the GPIB standoffs. Carefully pull the rear panel away from the main board.
6 Repair Guide Reassembly Instructions Instructions Visual • The reassembly process is simply the reverse of the disassembly process. However, there are various points to be aware of: • USB/LAN connectors must rest on top of the rear panels’ EMC spring fingers. • The position of the cable clamp depends on whether option 101 or 003 is fitted. • The main board connector from the PSU must be pushed firmly to fully engage it. • Take care not to trap any cables when fitting the top clamshell.
Repair Guide Instructions 6 Visual • Sensor RF connections (Figure 6-17): E – Channel A(+), Black cable F – Channel A(–), Black/White cable G – Channel B(+), Black cable H – Channel B(–), Black/White cable Note: • Only connect E and F for N1911A • Connect E, F, G, H for N1912A F H E G Figure 6-17 • PSU screw locations (Figure 6-18): A – Attach PSU to clamshell (6 screws) B – Attach PSU cable guide (1 screw) C – Attach PSU safety cover (4 screws) C A C B A Figure 6-18 N1911A/1912A P-Series Power
6 Repair Guide Instructions Visual • PSU cable routing (Figure 6-19): Ensure the PSU cables are positioned such that the cable guide does not trap them or pinch them.
Repair Guide 6 Disassembly vs Part Replacement Disassembly of Replacement Part Instructions Main board / Rear panel assembly / Bottom clamshell • Full strip-down required PSU / Top clamshell • Remove handle, bumpers, and top clamshell (including PSU) • PSU can now be removed from the top clamshell Fan assembly • Remove handle, bumpers, and top clamshell (including PSU) • Disconnect fan assembly from the main board • Fan assembly can now be removed PPMC assembly (front connectors option) • Remove
6 96 Repair Guide Disassembly of Replacement Part Instructions DAP assembly, Channel A (Rear connectors option) • Remove handle, bumpers, and top clamshell (including PSU) • Disconnect the sensor RF connections from the main board • Remove the 4 screws securing the DAP assembly to the main board • DAP assembly can now be removed DAP assembly, Channel B • Remove handle, bumpers, and top clamshell (including PSU) • Remove the 4 screws securing the DAP assembly to the main board • DAP assembly can now
Repair Guide Disassembly of Replacement Part Instructions Sensor flex assembly (rear connectors option) • Remove handle and front/rear Bumpers • Remove top clamshell (including PSU) • Disconnect the sensor RF connections from the main board • Disconnect the sensor flex connection from the Main Board • Use the N1912-61807 special tooling kit to remove the sensor flex assembly N1911A/1912A P-Series Power Meters Service Guide 6 97
6 Repair Guide Front Panel Disassembly Instructions Instructions Visual IMPORTANT NOTE: • The front panel assembly should only be repaired in a clean and dust-free environment. • Failure to do so may introduce contamination between the EMI shielded window and the display. • Also note that it may not be necessary to completely disassemble the front panel in order to repair or replace some of its parts. As such, this procedure should be tailored to suit the specific repair requirements.
Repair Guide Instructions Step 2: • Use ODU socket to remove N1912-61806 sensor flex assembly • Release the tab holding the flex cable to the display interface board, and then disconnect it 6 Visual Flex Cable White Plastic Plug Step 3: • Disconnect the white plastic plug from the display interface board Step 4: • Unlock the main plastic clip that holds the front panel sub-frame and display support molding together (situated beside the key flex circuit), and carefully pull them apart to separate them
6 Repair Guide Instructions Visual Step 5: • Remove the 4 screws that attach the display to the display support molding, and then disconnect it from the display interface board Step 6: • Lift the display interface board off of the plastic mounting lugs on the display support molding to separate them from one another 100 N1911A/1912A P-Series Power Meters Service Guide
Repair Guide Instructions 6 Visual Step 7: • Remove the 3 screws that attach the calibrator assembly to the display support molding, and separate them from one another Note: • Take care not to damage the EMI spring fingers on the calibrator assembly EMI Spring Finger Step 8: • Disconnect the backlight cable assembly from the display interface board and inverter board Step 9: • Remove the 2 screws that attach the display inter face board to the inverter board, and separate them from one another N1911A
6 Repair Guide Instructions Visual Step 10: • Release the metal tabs holding the EMI screen to the front panel sub-frame, and separate them from one another Step 11: • Disengage the rubber tabs that attach the key flex circuit to the keymat, and carefully lift it out Step 12: • Remove the EMI shielded window and the keymat from the front panel sub-frame 102 N1911A/1912A P-Series Power Meters Service Guide
Repair Guide 6 Front Panel Reassembly Instructions Instructions Visual Step 1: • Insert the keymat into the front panel Sub-Frame Step 2: • Insert the EMI shielded window into the keymat, ensuring that it is clean and free from fingerprints Step 3: • Overlay the key flex circuit onto the keymat, ensuring that all of the rubber lugs are engaged to hold it securely N1911A/1912A P-Series Power Meters Service Guide 103
6 Repair Guide Instructions Visual Step 4: • Overlay the EMI screen onto the key flex circuit, ensuring that all of the metal tabs are engaged to hold it securely Step 5: • Fit the display interface board onto the plastic mounting lugs on the display support molding 104 N1911A/1912A P-Series Power Meters Service Guide
Repair Guide Instructions 6 Visual Step 6: • Attach the inverter board to the display interface board using the 2 screws removed earlier Step 7: • Connect the inverter board to the display interface board using the backlight cable assembly Note: • The cable must be tucked under the plastic clip to prevent any fouling Step 8: • Attach the calibrator assembly to the display support molding using the 3 screws removed earlier Step 9: • Carefully spread the EMI fingers outwards, ensuring they extend beyond
6 Repair Guide Instructions Visual Step 10: • Fit the split washer to the calibrator assembly Step 11: • Attach the display to the display interface board using the 4 screws removed earlier Step 12: • Connect the white plastic plug to the display interface board 106 N1911A/1912A P-Series Power Meters Service Guide
Repair Guide Instructions 6 Visual Step 13: • Attach the front panel sub-frame to the display support moulding, ensuring that all plastic clips are engaged to hold it securely Step 14: • Connect the flex cable to the display interface board, and then tighten the locking tab Step 15: • Re-fit the calibrator plug • This step is only applicable for calibrator assembly with the calibrator plug. • For more information on the improved calibrator assembly, refer to “Improved calibrator assembly” on page 78.
6 Repair Guide Additional Repair Notes Replacing A Sensor Flex Assembly: • The Sensor flex assembly is supplied straight • Create A sharp bend (Figure 6- 20): The flex circuit must be bent at a right- angle where it meets the printed circuit board. It can only be bent after heat has been applied to it (i.e.
Repair Guide 6 Main Board vs.
6 Repair Guide Replacing the PPMC Assembly • The PPMC assembly is pre- programmed with N1912A firmware • Always perform a firmware firmware to the instrument if the PPMC assembly has been replaced NOTE • Fitting a PPMC assembly that has been pre-programmed with N1912A firmware to an N1911A power meter will generate errors; these errors will disappear once the firmware upgrade procedure has been carried out.
Repair Guide 6 Replacing the Calibrator Semi-Rigid/Split Ferrite Instructions • Separate the two halves of the ferrite (Figure 6-23) • Position the ferrite such that it’s furthest edge is 120 mm (4 ¾”) from the bend of the semi-rigid (Figure 6-24) • Hold the ferrite in place by applying a coating of silicone or silicone-rubber compound (e. g.
6 Repair Guide THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.
N1911A/1912A P-Series Power Meters Service Guide 7 Contacting Keysight Technologies Introduction 114 Before Calling Keysight Technologies 115 Check the Basics 116 Instrument Serial Numbers 117 Keysight Sales and Service Offices 118 Returning Your Power Meter for Service 119 Useful Web Pages 120 This chapter details what to do if you have a problem with your power meter.
7 Contacting Keysight Technologies Introduction Contacting Keysight Technologies This section details what to do if you have a problem with your power meter. If you have a problem with your power meter, first refer to the page titled “Before Calling Keysight Technologies”. This section contains a checklist that helps identify some of the most common problems.
Contacting Keysight Technologies 7 Before Calling Keysight Technologies Before calling Keysight Technologies or returning the power meter for service, please make the checks listed in “Check the Basics” on page 116. If your power meter is covered by a separate maintenance agreement, please be familiar with the terms. Keysight Technologies offers several maintenance plans to service your power meter after warranty expiration. Call your Keysight Technologies Sales and Service Center for full details.
7 Contacting Keysight Technologies Check the Basics Problems can be solved by repeating what was being performed when the problem occurred. A few minutes spent in performing these simple checks may eliminate time spent waiting for instrument repair. Before calling Keysight Technologies or returning the power meter for service, please make the following checks: • Check that the line socket has power. • Check that the power meter is plugged into the proper ac power source.
Contacting Keysight Technologies 7 Instrument Serial Numbers Keysight Technologies makes frequent improvements to its products to enhance their performance, usability and reliability. Keysight Technologies service personnel have access to complete records of design changes for each instrument. The information is based on the serial number and option designation of each power meter. Whenever you contact Keysight Technologies about your power meter have a complete serial number available.
7 Contacting Keysight Technologies Keysight Sales and Service Offices In any correspondence or telephone conversations, please refer to the power meter by its model number and full serial number. With this information, the Keysight representative can quickly determine whether your unit is still within its warranty period.
Contacting Keysight Technologies 7 Returning Your Power Meter for Service Use the information in this section if you need to return your power meter to Keysight Technologies. Packaging the power meter for shipment to Keysight Technologies for service • Fill in a blue service tag (available at the end of most hardcopy Keysight Service Guides) and attach it to the power meter. Please be as specific as possible about the nature of the problem.
7 Contacting Keysight Technologies Useful Web Pages • Main Product Page www.keysight.com/find/wideband_powermeters • Product Manuals www.keysight.com/find/pseriesmanuals • Product Firmware www.keysight.com/find/pseriesfirmware • Performance Test & Calibration Software www.cal.software.keysight.com • Service Notes www.literature.keysight.com/LitWeb/Admin/SNSelectForTM.
www.keysight.
This information is subject to change without notice. © Keysight Technologies 2006 - 2014 Edition 14, November 2014 *N1912-90015* N1912-90015 www.keysight.
