Page 1: Noise Figure Analyzers
Keysight NFA Series Noise Figure Analyzers This manual provides documentation for the following analyzers: N8973B (10 MHz – 3.6 GHz) N8974B (10 MHz – 7 GHz) N8975B (10 MHz – 26.5 GHz) N8976B (10 MHz – 40 GHz) Notice: This document contains references to Agilent.
Page 2: Safety Notices
DOCUMENT OR ANY INFORMATION reproduce, release, perform, CONTAINED HEREIN. SHOULD display, or disclose commercial KEYSIGHT AND THE USER HAVE A computer software or SEPARATE WRITTEN AGREEMENT commercial computer software WITH WARRANTY TERMS documentation. No additional...
Page 3 Documentation is updated periodically. For the latest information about this instrument, including firmware upgrades, application information, and product information, click the website link below. http://www.keysight.com/find/nfa To receive the latest updates by email, subscribe to Keysight Email Updates at the following URL: http://www.keysight.com/find/MyKeysight Information on preventing instrument damage can be found at: www.keysight.com/find/PreventingInstrumentRepair...
Page 5: Table Of Contents
Keysight NFA Series Noise Figure Analyzer Overview ........
Page 6 Instrument Hangs at the Keysight Splash Screen ........
Page 7 Contents RF Section Description ............... 134 Purpose .
Page 8 Contents A14 L.O. Synthesizer Assembly Description ............270 Purpose .
Page 9 Contents 11. Front Panel/Motherboard Troubleshooting What You Will Find in This Chapter ............. 317 A8 Motherboard Description .
Page 10 RF Front End Assembly (N8973B, 74B, 75B) ........
Page 11 Contents Disk Drive Interconnect ..............437 Analog I.F.
Page 12 Contents Procedure ................510 Scale Fidelity.
Page 13: Overview
What You Will Find in This Chapter This chapter provides overview information on your spectrum analyzer. The following sections are found in this chapter: Keysight NFA Series Noise Figure Analyzer Overview on page 14 Analyzer Accessories on page 15 Before You Start Troubleshooting on page 18...
Page 14: Keysight Nfa Series Noise Figure Analyzer Overview
An external simulated LO to the input of a frequency translating device can be achieved by connecting to a Keysight signal generator over LAN, USB, or GPIB. LO control is adjusted from the NFA.
Page 15: Analyzer Accessories
Overview Analyzer Accessories Analyzer Accessories A number of accessories are available from Keysight Technologies to help you configure your analyzer for your specific applications. They can be ordered through your local Keysight Sales and Service Office and are listed below.
Page 16: 50 Ohm Load
909D: DC to 26.5 GHz 50 Ohm/75 Ohm Minimum Loss Pad The Keysight 11852B is a low VSWR minimum loss pad that allows you to make measurements on 75 Ohm devices using an analyzer with a 50 Ohm input. It is effective over a frequency range of DC to 2 GHz.
Page 17: Power Splitters
Overview Analyzer Accessories The Keysight 11947A Transient Limiter protects the analyzer input circuits from damage due to signal transients. It specifically is needed for use with a line impedance stabilization network (LISN). It operates over a frequency range of 9 kHz to 200 MHz, with 10 dB of insertion loss.
Page 18: Before You Start Troubleshooting
Any interruption of the protective conductor inside or outside of the product is likely to make the product dangerous. Intentional interruption is prohibited. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 19: Lithium Battery Disposal
A4 CPU assembly to power the instrument clock and back up data in SRAM. When the battery is exhausted and ready for disposal, dispose of it according to your country’s requirements. The Keysight part number is 1420-0356. The manufacturer’s part number is CR2032. You can return the battery to your nearest Keysight Technologies Sales and Service office for disposal, if required.
Page 20: Esd Information
1 megohm of isolation from ground. These techniques for a static-safe workstation should not be used when working on circuitry with a voltage potential greater than 500 volts. Figure 1-1 Example of a Static-Safe Workstation Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 21: Handling Of Electronic Components And Esd
For more information about preventing ESD damage, contact the Electrical Over Stress/Electrostatic Discharge (EOS/ESD) Association, Inc. The ESD standards developed by this agency are sanctioned by the American National Standards Institute (ANSI). Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 22: Service Equipment You Will Need
— USB Keyboard and Mouse — USB Storage Device — Test Equipment Calibration Application Software Information regarding the Keysight X-Series Signal Analyzer Calibration Application Software can be found at the following web site: http://www.keysight.com/find/calibrationsoftware Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 23: Front End Controller Troubleshooting Kit
Part of N9020-60005 Troubleshooting kit Cable, YTF Preselector E4410-60158 Part of N9020-60005 Troubleshooting kit Cable, Input Attenuators E4410-60157 Part of N9020-60005 Troubleshooting kit Cable, Troubleshooting 8121-1400 Connector, MMCX (f) to SMA (f) www.hubersuhner.com item number: 31_MMCX-SMZ-50-1/111_OE Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 24: Usb Keyboard And Mouse
Recommended size is 2 gigabytes minimum, to allow storing at least one instrument software installer file. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 25: Required Test Equipment List
Only the recommended and alternate equipment is compatible with the performance verification testing. Some tests can use various models of a particular equipment type. The “Recommended Keysight Model” is the preferred equipment. However, the “Alternative Keysight Model” is an acceptable substitute.
Page 26 AC Accuracy: ± 0.31% of reading Power Meter Dual Channel N1914A E4419A/B A, P Instrumentation Accuracy: ± 0.5% N1912A Power Reference Accuracy: ± 0.6% Compatible with 8480 series power sensors dB relative mode Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 27 2 GHz to 12.4 GHz: 1.15:1 12.4 GHz to 18 GHz: 1.20:1 18 GHz to 26.5 GHz: 1.25:1 26.5 GHz to 40 GHz: 1.30:1 40 GHz to 50 GHz: 1.50:1 Input Connector: 2.4 mm (m) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 28 Accuracy: < ±1 e10 Symmetricom 5071A-C001 50 MHz, Frequency Drift: < 2.5 kHz Z5602B Z5602A −25 dBm Calibrator Typical VSWR: 1.06:1 (Option H51) (Option H51) Output Power Variation: ±.004 dB Total Harmonic Content: −45 dBc Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 29 Connector: 3.5 mm (m, f) 20 dB Frequency: 10 MHz 8491A 8491B A, P Fixed Attenuator Loss: 20 dB (nominal) (Option 020) (Option 020) VSWR: 10 MHz: ≤ 1.20:1 Connector: Type-N (m, f) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 30 2 GHz to 3 GHz: 30 dB VSWR: ≤ 2 GHz: ≤ 1.15:1 ≤ 3 GHz: ≤ 1.22:1 Insertion Loss: ≤ 1.5, +0.1 dB/GHz (nominal) Coupling (nominal): 16 dB Connector: Type N (f) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 31 VSWR: ≤ 18 GHz: 1.4:1 Insertion Loss: 1.5 dB Frequency: DC to 10 MHz 8120-2582 10503A A, P, T (3 required) 50 Ω Coax BNC (m), both ends 120 cm (48 in.) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 32 Frequency: DC to 18 GHz 1250-1745 A, P (for 3.5 mm source) VSWR: ≤ 1.08:1 Type-N (f) to 3.5 mm (m) Frequency: DC to 18 GHz 1250-1750 A, P VSWR: ≤ 1.14:1 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 33 1 GHz Notch Filter Center Frequency: 1.0001 GHz Trilithic (for alternate Phase Noise CFN-2-1000.1 setup) a. Keysight model numbers unless otherwise noted. b. A = Adjustments, P = Performance Testing, T = Troubleshooting Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 34 Test uncertainty analysis. Lower cal factor uncertainties will translate to wider test margins. e. When ordering a new STD or CFT Power Sensor from Keysight to be used with the N7800A series applications, order with Option 1A7. The 1A7 option provides an ISO17025 calibration and includes calibration data.
Page 35 10 dB Step Attenuator Nominal Attenuation Attenuator Section Allowable Uncertainty (dB) (dB) (10 dB) (20 dB) (40 dB) (40 dB) 0 (Reference) < 0.010 < 0.015 < 0.020 < 0.025 < 0.030 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 36 10 dB Step Attenuator Nominal Attenuation Attenuator Section Allowable Uncertainty (dB) (dB) (10 dB) (20 dB) (40 dB) (40 dB) < 0.035 < 0.040 a. TME requires that Section 3 be characterized. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 37: After An Instrument Repair
After an Instrument Repair If any instrument assemblies have been repaired or replaced, perform the related adjustments and performance verification tests. These tests are done using the N7814A Keysight X-Series Signal Analyzer Calibration Application Software. Refer to Chapter 16, “Post-Repair Procedures,”...
Page 38: Contacting Keysight Technologies
1-4. In any correspondence or telephone conversations, refer to the instrument by its model number (ex. N8975B) and full serial number (ex. MY56080147). With this information, the Keysight representative can quickly determine whether your unit is still within its warranty period.
Page 39 (65) 6375 8100 Europe and Middle Country Phone Number Austria 0800 001122 Belgium 0800 58580 Finland 0800 523252 France 0805 980333 Germany 0800 6270999 Ireland 1800 832700 Israel 1 809 343051 Italy 800 599100 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 40 0800 0233200 Russia 8800 5009286 Spain 0800 000154 Sweden 0200 882255 Switzerland 0800 805353 Opt. 1 (DE) Opt. 2 (FR) Opt. 3 (IT) United Kingdom 0800 0260637 For other unlisted countries: http://www.keysight.com/find/contactus Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 41: Instrument Serial Numbers
Instrument Serial Numbers Keysight makes frequent improvements to its products enhancing performance, usability, or reliability. Keysight service personnel have access to complete records of design changes to each type of instrument, based on the instrument’s serial number and option designation.
Page 42: How To Return Your Instrument For Service
How to Return Your Instrument for Service How to Return Your Instrument for Service Service Order Number If an instrument is being returned to Keysight for servicing, the phone numbers are mentioned in Table 1-4, “Contacting Keysight,” on page 39. In order for Keysight to expedite the repair please be as specific as possible about the nature of the failure.
Page 43: Other Packaging
5. Seal the shipping container securely with strong nylon adhesive tape. 6. Mark the shipping container “FRAGILE, HANDLE WITH CARE” to assure careful handling. 7. Retain copies of all shipping papers. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 44 Overview How to Return Your Instrument for Service Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 45: Boot Up And Initialization Troubleshooting
Fan(s) Are Not Operating on page 56 No Keysight Splash Screen Displayed on page 58 Instrument Hangs at the Keysight Splash Screen on page 59 PCI Enumeration Error on page 59 Instrument Cannot Completely Load or Run the Operating System...
Page 46: Check The Basics
Boot Up and Initialization Troubleshooting Check the Basics Check the Basics Before calling Keysight Technologies or returning the instrument for service, please make the following checks: 1. Is there power at the power outlet? At the power receptacle on the instrument? 2.
Page 47: Instrument Boot Up Process
By default all applications are checked and therefore, will preload when the XSA application is launched. Uncheck any applications to bypass the preloading process, select Apply, and then OK to close the Configure Applications window when finished. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 48 Boot Up and Initialization Troubleshooting Instrument Boot Up Process Figure 2-1 Configure Application Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 49: Typical Instrument Boot-Up Process Flow
Operating” section in this chapter. 5. The Keysight Technologies splash screen is displayed in white font on a dark background for ~5-10 seconds after the analyzer is turned on. If the Keysight Technologies logo is not displayed refer to the “No Keysight...
Page 50 291 in this manual. 8. The Keysight Technologies logo is displayed in white font on a black background while Windows finishes loading user preferences. This can take up to 4 minutes. If this does not occur refer to the “Instrument Cannot...
Page 51 Boot Up and Initialization Troubleshooting Instrument Boot Up Process Figure 2-2 Typical Instrument Sweep at Power-up Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 52: Potential Problems During Boot Process
2. Remove the AC power cord and then remove the instrument cover. Refer to the Chapter 15, “Assembly Replacement Procedures”, on page 389 this manual. 3. Refer to Figure 2-3, verify the +5.1V standby LED on the A7 Midplane board is on. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 53 A4 CPU board are not at fault, replace the A4 CPU board. If no: Replace the A6 Power Supply assembly. Before replacing the power supply, verify the midplane and motherboard interconnects are mechanically secure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 54: Green Power On Led Does Not Illuminate
Does the voltage at R867 measure 5 VDC? If yes: Proceed to step If no: Replace the A6 Power Supply assembly. Before replacing the power supply, verify the midplane and motherboard interconnects are mechanically secure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 55 A4 CPU board are not at fault, replace the A4 CPU board. If no: Replace the A6 Power Supply assembly. Before replacing the power supply, verify the midplane and motherboard interconnects are mechanically secure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 56: Fan(S) Are Not Operating
Measure the voltage level at TP1 on the A7 Midplane board. Is the TP1 voltage between +7 and +15 VDC If yes: Proceed to step If no: Replace the A6 Power Supply assembly. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 57 Replace the fan(s) that is not working If no: After verifying that the connections between the A7 Midplane board and the A8 Motherboard are mechanically and electrically secure replace the A8 Motherboard. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 58: No Keysight Splash Screen Displayed
No Keysight Splash Screen Displayed (Black background with white “Keysight Technologies” text) A problem of not displaying the Keysight splash screen could be caused by many different things. It could be due to a down power supply, a processor hardware problem, an instrument boot-up process error, a display section failure, etc.
Page 59: Instrument Hangs At The Keysight Splash Screen
Potential Problems During Boot Process Instrument Hangs at the Keysight Splash Screen A problem of the instrument hanging at the Keysight splash screen could be caused by many different things. It could be due to a down power supply, a processor hardware problem, an instrument boot-up process error, etc.
Page 60: Instrument Cannot Completely Load Or Run The Operating System
It could be due to a down power supply, a processor hardware problem, an instrument boot-up process error, corrupt hard drive, etc. This procedure assumes that the instrument can get past the Keysight splash screen at power on. If it doesn't, refer to the “Instrument Hangs at the Keysight Splash Screen”...
Page 61: Verify Video Signal Path Integrity
— Initializing Message Services (3 of 7) — Initializing Hardware (4 of 7) — Initializing Data Services (5 of 7) — Initializing SCPI Services (6 of 7) — Initializing Front Panel EEPROM Services (7 of 7) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 62: Fails An Initial Alignment
Assure there is no 50 MHz signal above 0 dBm applied to the signal analyzer input when the alignment routine is performed. This can cause errors. The description of the alignment and the alignment hardware dependencies are listed in Table 2-1, “Initial Alignments,”. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 63 A2 Analog IF A3 Digital IF or Algorithm A16 Reference Adjusts Centering, symmetry and dip of the crystal prefilter BW set to about 80 kHz Uses 322.5 MHz Comb Calibrator on the A-IF Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 64 Reference Measures the attenuation of all DC coupled, and one AC coupled (10 dB) settings of the RF input attenuators. Reference atten setting is 10 dB Narrow Band Step Cal Alignment Algorithm Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 65 Detects the level of the signal envelope before filtering at the 22.5 MHz IF, and compares that detected level against the trigger threshold DC level. Trigger Interpolation A3 Digital IF DIF 25 Pulse Stretcher Alignment Algorithm A3 Digital IF Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 66: Signal Level Verification
The analyzer low band path is functioning properly at least at 50 MHz. If no: Refer to Chapter 4, “RF Section Troubleshooting (N8973B, 74B, 75B Analyzers)” in this manual. It is possible that other input frequencies < 3.6 GHz could have an amplitude problem even though the 50 MHz calibrator is within tolerance.
Page 67: Signal Level Problem With Input Frequencies > 3.6 Ghz
The analyzer high band path is functioning properly at least at 4.8 GHz. If no: Refer to Chapter 4, “RF Section Troubleshooting (N8973B, 74B, 75B Analyzers)” in this manual. It is possible that other input frequencies > 3.6 GHz could have an amplitude problem even though the 4.8 GHz calibrator is within tolerance.
Page 68 Boot Up and Initialization Troubleshooting Signal Level Verification Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 69: Instrument Messages
Keysight NFA Series Noise Figure Analyzers Service Guide Instrument Messages Introduction The Error and Status messaging system of the instrument reports events and conditions in a consistent fashion, as well as logging and reporting event history. Event vs. Condition Messages —...
Page 70: Event And Condition Categories
Warnings are logged in the error queues. If the warning is a condition, both the Detected and Cleared event messages are logged. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 71: Event Message Format
An explanation is included with each error to further clarify its meaning. Some errors are specified in industry standards, and may include references to Section 21.8 of the 1999 SCPI Syntax & Style Standard (http://www.ivifoundation.org/docs/scpi-99.pdf). Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 72: Event Queues
However, a status condition is usually caused by an internal event that is not related to a particular interface, so the Detected/Cleared Events for status conditions are reported to all the queues. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 73 Logged with the same severity (Error or Warning) as the Condition b. Logged with a “green” severity (Condition Resolved) c. Not logged, unless the cause of the Advisory was remotely generated, in which case a Warning mes- sage, type –221, is logged. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 74: Advisory Messages
If Marker Function is off, changing the band has no effect Band Adjust has no effect with Mkr Function Off Turning on any high-pass or low-pass filter turns off band pass filters Band-pass filter set to Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 75 The LO fixed freq should be greater than the RF freq’s for an LSB or DSB (for DSB measurements the setup uses LSB values) downconverter setup. Use the graph icon on the DUT setup form to clarify the setup required Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 76 The LO fixed freq should be greater than the IF Stop freq for an LSB upconverter fixed LO setup. Use the graph icon on the DUT setup form to clarify the setup required Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 77 <port> The Keysight Smart Noise Source has been connected and the application is Reading SNS data… reading the device EEPROM data. Please wait until complete before continuing A file recall (open/load) was successfully completed Recalled File <filename>...
Page 78 DVB-T masks minimum. Results may be inaccurate. Zero span is a display at a single frequency, so there is no “sweeping” to set up Sweep Setup is not available in Zero Span Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 79 The measurement setup has changed such that the current cal data can be applied User Cal valid. Apply Cal to the results. To apply the cal, press Meas Setup/Cal Setup/Apply Calibration. A from Meas Setup menu new cal can be performed if required Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 80: Event Messages
–221, such as Settings Conflict; Function not available in Zero Span. This helps you understand the exact cause of the Settings Conflict error. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 81: 800, Operation Complete Event
–440 A query was received in the same program message after a query requesting an Query UNTERMINATED indefinite response was executed after indefinite response Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 82: -300 To -399, Device-Specific Errors
Verbose/Correction Information –300 An instrument error occurred and the exact problem cannot be specifically Device-specific error identified. Report this error to the nearest Keysight Technologies sales or service office –310 An internal system-type error has occurred. The exact problem cannot be System error;...
Page 83 Memory error –312 Protected user data saved by the *PUD command has been lost PUD memory lost –313 The nonvolatile calibration data used by the *CAL? command has been lost Calibration memory lost Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 84 There was a problem with instrument remote communications. The exact Communication error problem cannot be specifically identified –360 The Keysight Smart Noise Source connected to the instrument has failed to be Communication error; read by the application. Please disconnect and reconnect the SNS. If this SNS data read continues to fail, then the SNS may have had its EEPROM corrupted or another failure.
Page 85: -221 Settings Conflict Errors
Source mode –221 Base Transceiver Station gain correction is not available in some Modes, or in Settings conflict; some measurements (for example, the SA measurement) BTS gain is not available in this Mode Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 86 Fixed marker –221 The continuous peak feature cannot be used while you are also using the Settings conflict; signal tracking function Continuous Peak is not available with Signal Track on Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 87 –221 This functionality is not a part of the instrument you are using, but may be Settings conflict; found in other models in the X-Series Feature not supported for this model number Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 88 Settings conflict; Function only available in Tracking Source mode –221 You cannot center or adjust the preselector because the Microwave Settings conflict; Preselector is currently off Function unavailable with MW Presel off Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 89 Type is set to FFT –221 The gated video function is not available if you have selected the FFT sweep Settings conflict; type Gated Video is not available while Sweep Type is set to FFT Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 90 Increase Mask unavailable for or decrease the span to display the mask current Span. Increase to display mask. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 91 View is on –221 The Normalize function works by doing trace manipulation, so if trace math is Settings conflict; on you cannot turn on normalization Normalize is not available while Trace Math is on Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 92 –221 To do Relative Triggering in this measurement requires optional hardware Settings conflict; that is not present in this analyzer Relative Trigger needs hardware support for this meas Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 93 –221 You cannot send the remote command to set the sweep time to auto while Settings conflict; you are in zero span Sweep Time cannot be auto-coupled while in Zero Span Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 94 If Point Trigger is being used with an external trigger input to synchronize an Settings conflict; external source to the analyzer, that trigger input is unavailable for triggering Trigger input in use for source synchronization Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 95 Detectors and Average detector can’t be used together –221 Frequency is limited to 1GHz while RF Input 2 is enabled Settings conflict;Freq > 1 GHz is not available while RF Input 2 enabled Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 96: -200 To -299, Execution Errors
This section lists all messages in the range except –221 error messages. For details of –221 messages, see “–221 Settings Conflict Errors” on page Note that Execution Errors are divided into subclasses, as follows: –21x Trigger errors –22x Parameter error Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 97 Algorithm failed to center the preselector. This maybe caused by the signal Execution Error; peak being too low in amplitude, or it could be due to excessive CW input Preselector centering signal, alignment error, or hardware failure failed Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 98 The signal selected is not the list. You only can perform the operation on signal Signal Selected is that is already available in the list not in the Signal List –201 The command cannot be executed while the instrument in Local control Invalid while in local Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 99 –223 A data element (of block, expression, array type, or string type) had more data Too much data then allowed by the command, or by the available memory Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 100 When querying the LXI Event Log or the Servo Log, an index may be used to Illegal parameter look at a specific entry. This error occurs if the index provided does not point to value; Index out of a valid entry range Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 101 Data corrupt or data from must be the current active measurement. Maybe you have not stale; Measurement initiated the measurement, or it has not completed all the sweeps/averages data is not available needed Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 102 A problem was found with the mass storage device (memory, disk drive, etc.). Mass storage error; The exact problem cannot be specifically identified –250 Access is denied Mass storage error; Access denied –250 The specified path is invalid Mass storage error; Bad path name Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 103 You have used the *RCL command to recall a state register that wasn’t error previously saved with the *SAV command –250 The process cannot access the file because another process has locked a Mass storage error; portion of the file Lock violation Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 104 A legal command or query could not be executed because there was an error File name error; with the file name on the device media. For example, maybe you tried to copy to a duplicate file name Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 105 Indicates that a syntactically legal macro label in the *GMC? query could not be Macro header not executed because the header was not previously defined found –280 There was an execution error in a down-loaded program. The exact problem Program error cannot be specifically identified Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 106 Out of memory –292 Referenced name does not exist –293 Referenced name already exists –294 Indicates that the type or structure of a memory item is inadequate Incompatible type Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 107: -100 To -199, Command Errors
The mantissa of a decimal-numeric contained more than 255 digits, excluding Too many digits leading zeros –128 A legal numeric data element was found, but that is not a valid element at this Numeric data not position in the command allowed Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 108 A problem was found with a macro element. The exact problem cannot be Macro error specifically identified –181 Indicates that a macro parameter placeholder was encountered outside of a Invalid outside macro macro definition definition Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 109: Error
0 Error Err# Message Verbose/Correction Information The queue is empty. Either every error in the queue has been read, or the queue No error was cleared by power-on or *CLS Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 110: Condition Messages
STATus:QUEStionable:CALibration register, as described in section “Condition Errors 36 to 64, Calibration Needed or Failed” on page 111. Err# Bit in Message Error or More Information status Warning register Align RF Skipped unused unused unused unused unused Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 111 PTRansition filter set, or a true-to-false transition with the NTRansition filter set, in any of the :CALibration sub-registers :SKIPped, :EXTended:NEEDed or :EXTended:FAILure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 112 This bit is the summary bit for the Align Skipped Sum Summary only STATus:QUEStionable:CALibration:SKIP ped sub-register. Align Now, RF required unused In PSA, this was error 64 Align Now, All required Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 113 Corrected measurements have been Input Attenuation not requested and the required RF front-end calibrated setting of x dB has not been calibrated. unused unused unused unused unused unused unused unused unused unused Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 114 In PSA, this was error 13751 Align 30MHz to 1GHz failed The preselector characterization routine failed. Characterize Preselector failure unused unused unused unused unused unused unused unused unused unused unused unused Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 115: Condition Errors 101 To 199, Measurement Integrity
To calculate Timing and Phase results in the No Result;Turn on MCE Code Domain Power view of Mod Accuracy, the "Multi Channel Estimator" must be set to ON. Otherwise these results are invalid. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 116 A measurement is attempted or a SCPI query Insufficient Data; Loss of a before or after loss table is made and there table empty are no entries in the relevant loss table Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 117 AF Spectrum RBW or the RF Spectrum RBW, decrease the Channel BW, and/or decrease the Demod Waveform Sweep Time. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 118: Condition Errors 201 To 299, Signal Integrity
When the condition is cleared, an event with the error number plus 1000 is generated. These error numbers can be viewed in the Show Errors screen, along with the DETECTED and CLEARED indicators. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 119 You may need to extend the search length. In PSA, this error was reported as one of the following error numbers: 10772, 13104, 10160, 10286, 10420, 10454, 10614, 10904, 10928, 13074, 10287 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 120 Failed to find the uplink slot, which caused the Sync synchronization with the Midamble to fail. Error;Midamble sync fail Burst type is "Data" or "Preamble" and the Sync measurement cannot find a Preamble Error;Preamble length zero Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 121 This may be caused by an interval too incorrect data capture. short There is no active channel detected. Demod Error;No active channel There is no active slot detected. Demod Error;Not an active slot Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 122: Condition Errors 301 To 399, Uncalibrated Integrity
Condition Errors 301 to 399, Uncalibrated Integrity This series of errors corresponds to the bits in the STATus:QUEStionable:INTegrity:UNCalibrated sub-register. The second column in the table shows the corresponding bit in that register. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 123 Signal ID on No Long Code Phase AC input coupling will function at lower AC coupled: Accy frequencies, but the performance is not specified unspec’d <10 MHz below 10 MHz. User cal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 124 (UNCAL) The measurement frequency range has been User Cal; Cal will be changed such that it is a subset of the calibrated interpolated range. (~CAL) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 125 Preamp will function at lower frequencies, but the Preamp: Accy unspec’d performance is not specified below XX kHz (XX is <XX kHz model number specific). unused unused unused unused unused unused unused Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 126: Condition Errors 401 To 499, Power
Condition Errors 501 to 599, Frequency This series of errors corresponds to the bits in the STATus:QUEStionable:FREQuency register (s. The second column in the table shows the corresponding bit in that register. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 127 In PSA, this error was reported as error The pulse reference signal is missing or is Ref missing or out of not within the correct amplitude range. range; Pulse unused unused unused unused Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 128: Condition Errors 601 To 699, Error Summaries
STATus:QUEStionable:TEMPerature sub-register. status bit This bit is the summary bit for the Frequency only STATus:QUEStionable:FREQuency sub-register. unused unused status bit This bit is the summary bit for the Calibration only STATus:QUEStionable:CALibration sub-register. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 129: Condition Errors 701 To 799, Operation
Warning register status bit Calibrating only status bit Settling only unused status bit Sweeping only status bit Measuring only status bit Waiting for Trigger only status bit Waiting for Arm only Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 130: Condition Errors 801 To 899, Temperature
“Condition Errors 601 to 699, Error Summaries” on page 128. Err# Bit in Message Error or More Information status Warning register (not currently in use) Reference Oscillator Oven Cold Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 131 Instrument Messages Condition Messages Err# Bit in Message Error or More Information status Warning register unused unused unused unused unused unused unused unused unused unused unused unused unused unused Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 132 Instrument Messages Condition Messages Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 133: Rf Section Troubleshooting (N8973B, 74B, 75B Analyzers)
Keysight NFA Series Noise Figure Analyzers Service Guide RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) What You Will Find in This Chapter The following information is found in this chapter: 1. Theory of operation of the RF section 2. Isolating the cause of an hardware problem by verifying the functionality of assemblies in the RF section signal path.
Page 134: Rf Section Description
RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) RF Section Description RF Section Description Purpose This section covers only those model numbers listed below for the NFA Series Noise Figure Analyzers. — N8973B (10 MHz - 3.6 GHz) — N8974B (10 MHz - 7 GHz) —...
Page 135 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) RF Section Description The RF section is comprised of the following major assemblies: — A9 Input Attenuator A — A10 Input Attenuator B — A11 Low Band Switch Assembly — A12 YTF Preselector —...
Page 136 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) RF Section Description 1. RF input frequencies < 3600 MHz route through the low band path. Refer Chapter 12, “Block Diagrams” for details. The RF input signal level can be optimized by either Input Attenuator A or Input Attenuator B.
Page 137 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) RF Section Description 3. RF input frequencies from 13.6 GHz to 26.5 GHz go through high band path #2. Refer to Chapter 12, “Block Diagrams” for details. This signal level can be optimized by either Input Attenuator A or Input Attenuator B.
Page 138: Rf Section Theory Of Operation
Align routine will perform a rough centering during the preselector two-point tuning algorithm. However, when troubleshooting, press Amplitude, Signal Path, Presel Ad just to manually center the preselector. The YTF Preselector is not present in the N8973B. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 139 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) RF Section Description A14 L.O. Synthesizer Assembly The L.O. Synthesizer Assembly provides the 1st L.O. power that is required for the A13 RF Front End Assembly. The 1st L.O. has a frequency range from 3.80 to 8.70 GHz.
Page 140 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) RF Section Description A13 RF Front End Assembly This assembly is a self-contained microcircuit that is repaired at the assembly level. See Figure 4-1. Figure 4-1 A13 RF Front End Assembly View from Front Panel...
Page 141 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) RF Section Description Table 4-2 A13 RF Front End Signals Signal Name Description From RF Input 9 kHz to 3.59 GHz RF Input A11J2, Low Band Switch A13J2 Microwave Input 3.6 GHz to 26.5 GHz...
Page 142: Troubleshooting
RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Troubleshooting Quick Check to Verify the Low Band Signal Path The analyzer has an internal 50 MHz amplitude reference signal that is used to verify the low band path. Refer to Chapter 12, “Block Diagrams”...
Page 143 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Disconnect the W15 or W36 cable from A13J7 on the RF Front End Assembly (1) 322.5 MHz output. See Figure 4-2. Figure 4-2 W15 or W36 Location Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 144 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Connect A13J7 output to a functioning spectrum analyzer and verify the 322.5 MHz intermediate frequency is measuring −28.5 ± 3 dB using the same analyzer settings as in Figure 4-3. Figure 4-3 322.5 MHz Intermediate Frequency...
Page 145 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting If this power level is incorrect, the following assemblies need to be verified in the order listed using the 50 MHz internal calibrator signal. Be sure the 50 MHz calibrator is turned on Input/Output, RF Calibrator, 50 MHz when verifying the performance.
Page 146: Troubleshooting A Low Band Problem
RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Troubleshooting a Low Band Problem 1. Reference Assembly Verification Remove cable W19 from A9 Input Attenuator A (1) and measure the 50 MHz calibrator signal on the cable end with a functioning Spectrum Analyzer. Refer Figure 4-5.
Page 147 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting If the Reference assembly calibrator is functioning properly the 50 MHz calibrator signal will measure 50 MHz at −25 dBm ± 3 dB. See Figure 4-6. If this level is incorrect, the Reference assembly is most likely defective.
Page 148 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting 2. L.O. Synthesizer Assembly Verification Press the following keys on the analyzer: FREQ, 1 GHz Zero Span Refer to Figure 4-7. Disconnect cable W4 at A14J740 of the L.O. Synthesizer Assembly (1).
Page 149 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Connect the functioning Spectrum Analyzer and appropriate high frequency cable and connector to A14J740. Adjust the functioning Spectrum Analyzer to measure a signal at 6122.5 MHz at +16 dBm ± 4 dB as seen in Figure 4-8.
Page 150 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting If this power level is incorrect remove W6 at A14J200. Refer to Figure 4-7. Adjust the functioning spectrum analyzer to measure a signal at 4.800 GHz at +4.5 dBm ± 2 dB. See Figure 4-9.
Page 151 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting 3. Front End Control Assembly Verification Verifying the Front End Control Assembly requires the RF Front End Troubleshooting board E4410-60115 or kit number N9020-60005. The kit includes the troubleshooting board and associated interconnect cables. The...
Page 152 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Figure 4-10 RF Front End Troubleshooting Board Figure 4-11 RF Front End Troubleshooting Board Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 153 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting — Turn the instrument on and allow it to complete its full boot up process to the signal analyzer application. — Turn Auto Align off by pressing System, Alignments, Auto Align, Auto Align, Off on the analyzer.
Page 154 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Figure 4-12 Front End Troubleshooting Board Attenuation LEDs Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 155 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting When the input attenuation is changed from 0 dB to 2 dB, the 2 dB Step LED DS15 should illuminate. When the input attenuation is changed from 2 dB to 4 dB, DS15 and DS16 should be illuminated as per Table 4-3.
Page 156 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting 5. Input Attenuator B Control Logic Verification Press AMPTD, Attenuation, Mech Atten, 6 dB and verify the 6 dB Step LED DS17 is illuminated. Enter the input attenuation settings found in Table 4-4...
Page 157 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting 6. Low Band Switch Control Logic Verification Press Mode Preset on the analyzer. Press FREQ, 50 MHz, Span, 2 MHz on the analyzer. Connect the DVM positive lead to one of the In1A test points, and the negative lead to the bottom of R46 (blue resistor near the bottom) on the Front End Troubleshooting board.
Page 158 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting 7. YTF Preselector Control Logic Verification (All except N8973B) In order to properly measure the preselector tune output from the A15 Front End Control Assembly, the following items are required: — E9637A Banana plug to BNC (f) adapter —...
Page 159 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting If any of the preselector control currents do not match the levels shown in Table 4-8, the most probable causes are a misaligned YTF or the A15 Front End Control Assembly. Perform the YTF characterization (press System, Alignments, Advanced, Characterize Preselector) and re-check the control current at various center frequencies.
Page 160 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting 8. Front End Assembly Control Logic Verification Since the RF Front End Troubleshooting board is connected, now is a good time to test out the remaining control circuits from the A15 Front End Control Assembly.
Page 161 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Table 4-9 Front End Control Logic Test Point Description Instrument Settings Vol tage Tolerance (VDC) (VDC) S14B Sets path to either band 1 & 2 mixer or band CF 5 GHz +9.67 ±0.5...
Page 162 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Input Attenuator A Power Level Verification Press Mode Preset, Input/Output, RF Calibrator, 50 MHz, AMPTD, Attenuation, Mech Atten, 0 dB on the analyzer. Refer to Figure 4-13, remove cable W11 from A9 (1) Output. Measure the 50 MHz calibrator signal on the output of the attenuator using a functioning Spectrum Analyzer.
Page 163 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting The level should be −25 dBm ± 2 dB as shown in Figure 4-14. Figure 4-14 50 MHz Calibrator Signal on Output of Attenuator A Press Mech Atten and enter 2 dB. The 50 MHz calibrator signal measured on the functioning Spectrum Analyzer should measure 2 dB lower than the previous step (~−27 dBm).
Page 164 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Input Attenuator B Power Level Verification Press AMPTD, Attenuation, Mech Atten, 0 dB. Remove output cable W9 from A10 (2). Refer to Figure 4-13. Measure the 50 MHz calibrator signal on the output of the attenuator using a functioning Spectrum Analyzer.
Page 165 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Since the analyzer is equipped with standard Option FSA, press Mech Atten and enter 6 dB. The 50 MHz calibrator signal measured on the functioning Spectrum Analyzer should measure 6 dB lower than the previous step (~−31 dBm) as shown in...
Page 166 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Press Mech Atten and enter 10 dB. The 50 MHz calibrator signal measured on the functioning Spectrum Analyzer should measure 10 dB lower than the first step (~−35 dBm). Continue testing all the attenuation settings as described in Table 4-10.
Page 167 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting 1. It may be difficult to measure the higher attenuator settings using the -25 dBm internal calibrator signal. Use an external source with the frequency set to 50 MHz and adjust the output level to 0 dBm. This will increase the measured power levels noted in the table above by 25 dB.
Page 168 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting When the analyzer is tuned to a center frequency of 50 MHz, the Low Band switch should have minimal loss. Press Input/Output, RF Calibrator, 50 MHz, AMPTD, Attenuation, Mech Atten, 10 dB on the analyzer. Measure the 50 MHz calibrator signal on the output of A11J2 using a functioning Spectrum Analyzer.
Page 169: Quick Check To Verify High Band Rf Path #1
RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting If all the power levels and biasing from the A15 Front End Control Assembly measure correctly up to this point, the most probable cause would be the A13 RF Front End Assembly.
Page 170 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Disconnect cable W15 or W36 at A13J7, 322.5 MHz output on the Front End Assembly (1). See Figure 4-19. Figure 4-19 W15 or W36 Location Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 171 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Connect A13J7 output to a functioning spectrum analyzer and verify the 322.5 MHz intermediate frequency is measuring −32 ± 4 dB as shown in Figure 4-20. Figure 4-20 322.5 MHz Intermediate Frequency If this power level is correct the entire RF section is operating correctly in high band.
Page 172 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting High Band #2 RF signal path utilizes a high band mixer internal to the A13 RF Front End Assembly for RF input frequencies from 13 GHz to 26.5 GHz. Since all the control voltages and biasing were already fully tested, failures from 13 GHz - 26.5 GHz will most likely be caused by the A13 RF Front End...
Page 173: Troubleshooting A High Band Problem
RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Troubleshooting a High Band Problem 1. Reference Assembly Verification Refer to Figure 4-22. Remove cable W19 from A9 Input Attenuator A (1). Measure the 4.8 GHz calibrator signal on the cable end with a functioning Spectrum Analyzer.
Page 174 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting If the Reference Assembly calibrator is functioning properly the 4.8 GHz calibrator signal will measure 4.8 GHz at −28 dBm ± 3 dB as shown in Figure 4-23. If this level is incorrect, the Reference Assembly is most likely defective.
Page 175 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting 2. L.O. Synthesizer Assembly Verification Press the following keys on the analyzer: MODE/MEAS, Spectrum Analyzer, OK, Mode Preset FREQ, 5 GHz Zero Span Refer to Figure 4-24. Disconnect cable W4 at A14J740 of the L.O. Synthesizer Assembly (1).
Page 176 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Connect the functioning Spectrum Analyzer and appropriate high frequency cable and connector to A14J740. Adjust the analyzer to measure a signal at 5322.5 MHz at +16 dBm ± 4 dB as shown in Figure 4-25.
Page 177 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Adjust the functioning spectrum analyzer to measure a signal at 4.8 GHz at +4.5 dBm ± 2 dB as shown in Figure 4-26. Figure 4-26 4.8 GHz Signal If this power level is incorrect, the most probable cause is the A16 Reference Assembly.
Page 178 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting 3. Front End Control Assembly Verification If the Front End Control Assembly logic was verified in the 'Low Band Quick IMPORTANT Check' section above, skip to “Input Attenuator A Power Level Verification”...
Page 179 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Figure 4-27 RF Front End Troubleshooting Board Figure 4-28 RF Front End Troubleshooting Board Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 180 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting — Turn the instrument on and allow it to complete its full boot up process to the signal analyzer application. — Turn Auto Align off by pressing System, Alignments, Auto Align, Auto Align, Off on the analyzer.
Page 181 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Figure 4-29 Front End Troubleshooting Board Attenuation LEDs Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 182 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting When the input attenuation is changed from 0 dB to 2 dB, the 2 dB Step LED DS15 should illuminate. When the input attenuation is changed from 2 dB to 4 dB, DS15 and DS16 should be illuminated as per Table 4-11.
Page 183 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting 5. Input Attenuator B Control Logic Verification Press AMPTD, Attenuation, Mech Atten, 6 dB and verify the 6 dB Step LED DS17 is illuminated. Enter the input attenuation settings found in Table 4-12...
Page 184 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting 6. Low Band Switch Control Logic Verification Press Mode Preset on the analyzer. Press FREQ, 50 MHz, Span, 2 MHz on the analyzer. Connect the DVM positive lead to one of the In1A test points, and the negative lead to the bottom of R46 (blue resistor near the bottom) on the Front End Troubleshooting board.
Page 185 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting 7. YTF Preselector Control Logic Verification In order to properly measure the preselector tune output from the A15 Front End Control Assembly, the following items are required: — E9637A Banana plug to BNC (f) adapter —...
Page 186 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting In order to measure the control current correctly, press Restart on the analyzer in between each measurement. If any of the preselector control currents do not match the levels in Table 4-16, the most probable causes are a misaligned YTF or the A15 Front End Control Assembly.
Page 187 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting 8. Front End Assembly Control Logic Verification Since the RF Front End Troubleshooting board is connected, now is a good time to test out the remaining control circuits from the A15 Front End Control Assembly.
Page 188 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Table 4-17 Front End Control Logic Test Point Description Instrument Settings Vol tage Tolerance (VDC) (VDC) S14B Sets path to either band 1 & 2 mixer or band CF 5 GHz +9.67 ±0.5...
Page 189 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Tolerances should be used as a guideline. If any of the voltages measured do not match the levels in Table 4-17, the most probable cause is the A15 Front End Control Assembly. Once the switch control logic has been verified, turn off the instrument.
Page 190 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting The level should be −28 dBm ±2 dB as shown in Figure 4-31. Figure 4-31 4.8 GHz Calibrator Signal on Output of Attenuator A Press Mech Atten and enter 2 dB. The 4.8 GHz calibrator signal measured on the functioning Spectrum Analyzer should measure 2 dB lower than the previous step (~−30 dBm).
Page 191 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting The level should be −28 dBm ± 2 dB as shown in Figure 4-32. Figure 4-32 4.8 GHz Calibrator Signal on Output of Attenuator B Press Mech Atten and enter 6 dB. The 4.8 GHz calibrator signal measured on the functioning Spectrum Analyzer should measure 6 dB lower than the previous step (~−34 dBm).
Page 192 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting 1. It may be difficult to measure the higher attenuator settings using the -28 dBm internal calibrator signal. Use an external source with the frequency set to 4.8 GHz and adjust the output level to 0 dBm. This will increase the measured power levels noted in the table above by 28 dB.
Page 193 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Low Band Switch Power Level Verification (for High Band) Refer to Figure 4-33. Carefully disconnect both ends of the W8 cable at A11J3 and A12 (1) input. Figure 4-33 W8 Location Be careful not to short out components on the front panel interface board or the components on top of the A12 YTF Preselector when removing W8.
Page 194 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting Turn off auto align by pressing System, Alignments, Auto Align, Auto Align, IMPORTANT Off. Measure the 4.8 GHz calibrator signal on the output of A11J3 Low Band Switch high band output port using a functioning Spectrum Analyzer. The level should be −46 dBm ±...
Page 195 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting If the power level is correct, do not reconnect W8 at this time. Refer to Figure 4-35, disconnect W7 at A12 (1) output and install a connector such that the A12 YTF Preselector output can be measured.
Page 196 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting A12 YTF Preselector Power Level Verification Press Input/Output, RF Calibrator, 4.8 GHz, AMPTD, Attenuation, Mech Atten, 10 dB, Zero Span on the analyzer. Measure the 4.8 GHz calibrator on the output of W7 cable using a functioning spectrum analyzer. When the 4.8 GHz calibrator signal is used, there will be ~ 5 dB ±...
Page 197 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting • Input Attenuator A • Input Attenuator B • Low Band Switch • YTF Preselector • RF Front End Assembly — Input Attenuator A — Input Attenuator B — Low Band Switch —...
Page 198: High Band Preamp (Standard Option P07, P26)
RF Section Troubleshooting (N8973B, 74B, 75B Analyzers) Troubleshooting High Band Preamp (Standard Option P07, P26) The High Band preamp can be verified as follows: View the 4.8 GHz calibrator signal on screen. Press AMPTD, Signal Path, Internal Preamp, Full Range to activate the preamp. The expected operation is the signal level will not change more than ±...
Page 199: Rf Section Troubleshooting (N8976B)
Keysight NFA Series Noise Figure Analyzers Service Guide 5 RF Section Troubleshooting (N8976B) What You Will Find in This Chapter The following information is found in this chapter: 1. Theory of operation of the RF section. 2. Isolating the cause of an hardware problem by verifying the functionality of assemblies in the RF section signal path.
Page 200: Rf Section Description
This chapter will assume the default operation in Spectrum Analyzer mode. Therefore the IF frequency will be 322.5 MHz. IF Path Mode 10 MHz (standard) 322.5 MHz Spectrum Analyzer or IQ Analyzer 25 MHz (standard Option B25) 322.5 MHz IQ Analyzer Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 201 4800 MHz (2nd LO)). The 2nd IF output is at A13A1J7. This signal path is used for all frequency range options when the RF input frequencies are < 3600 MHz. The control voltages and biasing for these assemblies come from the A15 Front End Control assembly. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 202 The signal path for 34.5 GHz to 44 GHz operation is almost the same as the 3.6 GHz to 17.1 GHz path. The only difference is that Mixer #4 is used in this path. The LO is doubled for all tuned frequencies in this path. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 203: A9 Input Attenuator A
The preselector requires centering for optimum amplitude accuracy. The Auto Align routine will perform a rough centering during the preselector two point tuning algorithm. However, when troubleshooting, press Amplitude, Signal Path, Presel Ad just to manually center the preselector. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 204: A13 Rf Front End Assembly (N8976B)
This assembly contains the major front end conversion components. The A13 is repaired at the assembly level. Replacement A13 assemblies include the A13A1 1st IF Bandpass Filter. See Figure 5-1. Figure 5-1 A13 RF Front End Assembly View from Front Panel Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 205 — YTF Preselector (Input signals > 3.6 GHz) — Front End Assembly including switched filter — High Band Preamplifier — Low Band Preamplifier Refer to Chapter 6, “Front End Control Troubleshooting.” for detailed descriptions & troubleshooting procedures Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 206: Troubleshooting
To verify the high band path go to “Quick Check to Verify High Band RF Path” on page 216. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 207 Reconnect the W36 cable to A13J7. Flatness issues or power level problems at other input frequencies below 3600 MHz may exist. This type of problem can be diagnosed using an external source to verify performance. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 208 In order to gain access to the front end components, remove the front frame assembly, but leave the ribbon cable connected so you can still control the instrument. Remove the right side chassis. Refer to the removal procedures in Chapter 15, “Assembly Replacement Procedures.”. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 209: Troubleshooting A Low Band Problem
A11 Low Band Switch, the interconnect cables, or the control signals. The control signals are explained in Chapter 6, “Front End Control Troubleshooting”, on page 229. Figure 5-3 RF Section (N8976B) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 210 Power at A10 Input Attenuator Being Tested Attenuator Setting (dB) Output Port (dBm) (N8976B) 0 dBm (reference) Both set to through path −2 −4 −6 −8 −10 −20 −30 −40 −50 −60 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 211 Press the following keys on the analyzer: FREQ, 1 GHz Span Zero Span Refer to Figure 5-4. Disconnect cable W4 at A14J740 of the L.O. Synthesizer Assembly (1). Figure 5-4 W4 and W6 Location Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 212 A14J740. Adjust the functioning Spectrum Analyzer to measure a signal at 6122.5 MHz at +16 dBm ± 4 dB as seen in Figure 5-5. Figure 5-5 Measure 1st L.O. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 213 The input signal level was measured on W3 as part of the A11 Low Band Switch verification. The output signal level was measured at A13J7 during the quick check to verify the Low Band Signal Path. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 214 A13A1 IF Band Pass Filter is not separately replaceable, but being able to determine where the signal level is faulty, can aid in verifying the faulty assembly. See the block diagram for signal levels. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 215 Low Band second mixer: RF = LO + IF IF = RF − LO LO = RF − IF where RF in this case is the first IF signal (signal at A13J11) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 216: Quick Check To Verify High Band Rf Path
3.5 mm (m) to 2.4 mm (f) adapter To perform the following checks, it will be necessary to remove the outer cover and the top brace. See Chapter 15 for removal procedures. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 217 Turn off auto align by pressing System, Alignments, Auto Align, Auto Align, IMPORTANT Off. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 218 RF Section Troubleshooting (N8976B) Troubleshooting Disconnect cable W36 at A13J7, 322.5 MHz output on the Front End Assembly. See Figure 5-7. Select Span, 0 Hz. Figure 5-7 A13A1J7 Location (N8976B) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 219 4.8 GHz internal calibrator signal. 1. A11 Low Band Switch 2. A10 Input Attenuator B 3. A9 Input Attenuator A 4. A16 Reference Assembly (4.8 GHz calibrator) 5. A12 YTF Preselector 6. A13 Front End Assembly Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 220 Preselector adjust should be performed first before changing the A13 RF Front End Assembly. In order to gain access to the front end components, remove the side chassis (1) by removing the 16 screws (2). See Figure 5-9. Figure 5-9 Remove the Side Chassis Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 221: Troubleshooting A High Band Problem
To perform the YTF alignment, reconnect W7 cable, and press System, Alignments, Ad vanced, Characterize Preselector. The routine may take several minutes to align the YTF. Display the 4.8 GHz calibrator signal on Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 222 Input/Output, RF Calibrator, Off. If the signal level at the attenuator output is now correct, suspect the A9 Attenuator cal switch or a faulty control signal from the A15 Front End Controller assembly. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 223 Analyzer Under Test Power at A10 Output Input Attenuator Being Attenuator Setting (dB) Port (dBm) Tested 0 dBm (reference) Both set to through path −2 −4 −6 −8 −10 −20 −30 −40 −50 −60 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 224 Press the following keys on the analyzer: Mode Preset FREQ, 5 GHz Center Frequency Span, Zero Span Refer to Figure 5-12. Disconnect cable W4 at A14J740 of the L.O. Synthesizer Assembly (1). Figure 5-12 W4 and W6 Location Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 225 Figure 5-13 Measure 1st L.O. If this power level is incorrect remove W6 at A14J200. Refer to Figure 5-12. Connect the functioning spectrum analyzer to the cable output using the appropriate high-frequency cable. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 226 The input signal level was measured on W46 or W7 as part of the A13 Front End Input Verification. The output signal level was measured at A13J7 during the quick check to verify the High Band signal path. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 227 N is the harmonic mixing mode: N = 1 for 8.4 GHz to 17.1 GHz N = 2 for 17.1 GHz to 34.0 GHz N = 4 for 34.0 GHz to 44 GHz Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 228 RF Section Troubleshooting (N8976B) Troubleshooting Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 229: Front End Control Troubleshooting
Keysight NFA Series Noise Figure Analyzers Service Guide 6 Front End Control Troubleshooting What You Will Find in This Chapter The following information is found in this chapter: A15 Front End Control Description on page 230 A15 Front End Control Assembly Troubleshooting on page 235...
Page 230: A15 Front End Control Description
Depending upon the model number, one of two different A15 Front End Control board assemblies may be installed. The “EFEC-Lite” is installed in the N8973B, 74B, and 75B. The Enhanced Front End Control assembly (“EFEC”) is installed in the N8976B.
Page 231 A15 Front End Control Description Standard RF Assemblies Controlled by the A15: — A9 Input Attenuator A (4 dB total for the N8973B, 74B, and 75B, 10 dB total for the N8976B) — A10 Input Attenuator B (66 dB total for the N8973B, 74B, and 75B, 60 dB total for the N8976B) —...
Page 232 Front End Control Troubleshooting A15 Front End Control Description Figure 6-1 A15 Front View, Physical Connectors (EFEC) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 233 Front End Control Troubleshooting A15 Front End Control Description Figure 6-2 A15 Front View, Physical Connectors (EFEC-Lite) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 234 Preselector Tune Out N/A (test point only) J300 J300 YTF Bias Control Out To A12 J802 Low Noise Bypass Switch Logic Out Reserved for future use J100 J100 Motherboard Connector From A8 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 235: A15 Front End Control Assembly Troubleshooting
Input Attenuator B, Low Band Switch and some of the power supplies can be verified. The remaining control voltages and RF signals can be measured directly with a voltmeter, oscilloscope or functioning spectrum analyzer. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 236: Verifying Input Attenuator A, Input Attenuator B, Low Band Switch Logic And Power Supplies
Verifying Input Attenuator A, Input Attenuator B, Low Band Switch Logic and Power Supplies 1. Turn off the instrument. 2. Disconnect ribbon cables from A15J700 and A15J800 as shown Figure 6-3. Figure 6-3 Ribbon Cables at A15J700 and A15J800 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 237 N8973B, 74B, 75B N8976B 4. If the NFA is an N8973B, 74B, or 75B, also connect the Low Band Switch Control Cable, E4410-60160 between A15J700 and J2 of the RF Front End Troubleshooting board. Do not connect this cable if the model is an N8976B.
Page 238 7. Turn Auto Align off by pressing System, Alignments, Auto Align, Auto Align, Off on the analyzer. Resistors on the test board can get very hot. Handle with care. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 239 Chapter 2, “Boot Up and Initialization Troubleshooting”. Input Attenuator A Control Logic Verification (N8973B, 74B, 75B) Press MODE/MEAS, Spectrum Analyzer, OK, AMPTD, Attenuation, Mech Atten, 0 dB on the analyzer. Attenuation LED's DS15-20 on the test board should be off.
Page 240 DS14 through DS16 should be illuminated as per Table 6-5. Table 6-5 Input Attenuator A LED’s (N8976B) Attenuator Setting DS14 DS15 DS16 (dB) If this is incorrect, the most probable cause is the A15 Front End Control Assembly. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 241 Front End Control Troubleshooting A15 Front End Control Assembly Troubleshooting Input Attenuator B Control Logic Verification (N8973B, 74B, 75B) Press MODE/MEAS, Spectrum Analyzer, OK, AMPTD, Attenuation, Mech Atten, 6 dB on the analyzer and verify the 6 dB Step LED DS17 is illuminated.
Page 242 A15 Front End Control Assembly. Set the input attenuator back to 10 dB by pressing AMPTD, Attenuation, Mech Atten, 10 dB on the analyzer. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 243 In2A −9.90 In1B −10.0 In2B +10.0 If the voltages are not correct, the most probable cause is the A15 Front End Control board. The procedure above will not work on the N8976B. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 244 Low Band switch ribbon cable and the input attenuator ribbon that were originally plugged into the Front End Control board before testing the input attenuator and low band switch logic. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 245: Preselector Tune Output
Noise Figure application. Press Freq, Span, Zero Span on the analyzer. The preselector tune output voltage in high band should change when the center frequency of the analyzer is changed. Preselector tune output measurements are not valid for the N8973B. Table 6-10 Preselector Tune Output Voltages...
Page 246 A15 is changed out first before changing the YTF since the A15 board has easy access. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 247: Analog/Digital If Troubleshooting
Keysight NFA Series Noise Figure Analyzers Service Guide Analog/Digital IF Troubleshooting What You Will Find in This Chapter The following information is presented in this chapter: 1. Theory of operation of the IF section. 2. Isolating the cause of a hardware problem by verifying the functionality of assemblies in the IF section signal path.
Page 248 A2 Analog I.F. Troubleshooting on page 253 A3 Digital I.F. Assembly Description on page 260 A3 Digital I.F. Assembly Theory of Operation on page 261 A3 Digital I.F. Troubleshooting on page 263 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 249: 25 Mhz Bw If Section
LO Input (300 MHz signal from A16 Reference Assembly) 22.5 MHz Cal Comb Signal (from the A3 Digital I.F. Assembly) Outputs from the A2 22.5 MHz signal (to A3 Digital I.F. Assembly) RF Trigger Detector (to A3 Digital I.F. Assembly) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 250: A2 Analog I.f. Assembly Theory Of Operation
Assembly with the 22.5 MHz cal comb signal from the A3 Digital I.F. to allow calibration of the prefilters and overall passband phase and amplitude. The signal is attenuated by 20 dB if necessary. A limiter is used to reduce amplitude variation effects. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 251 The through path is used when the analyzer Res BW setting is 430 kHz and greater in analyzer swept mode. In IQ Analyzer mode or in Spectrum Analyzer mode with Sweep Type of FFT, the analyzer span setting determines the pre-filter settings. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 252 The Burst Carrier Trigger detector provides a binary signal to be used as a trigger based on the presence of an RF input signal or not. The variable gain amplifiers drive a detector and its output drives a comparator which generates the trigger signal. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 253: A2 Analog I.f. Troubleshooting
NFA is set to 10 dB. Look near the top of the display near the center and verify that Atten: 10 dB is visible. If needed change the input attenuator by pressing AMPTD, Attenuation, Mech Atten 10 dB on the analyzer. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 254 SMA connectors and cables. 10.Press Freq, 322.5 MHz, Span, 1 MHz, Peak Search on the functioning spectrum analyzer 11.The analyzer should read 322.5 MHz at −30 dBm ± 3 dBm as shown in Figure 7-2. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 255 Figure 7-2 A13 322.5 MHz Output If the 322.5 MHz signal is not measuring the correct power level, refer to Chapter 4, “RF Section Troubleshooting (N8973B, 74B, 75B Analyzers)” this service guide. Reconnect W15 at A13J7. Measuring at this location is for convenience. The 322.5 MHz signal is an IMPORTANT output at A13J7.
Page 256 Atten: 10 dB is visible. If needed change the input attenuator by pressing AMPTD, Attenuation, Mech Atten 10 dB on the analyzer. 8. Refer to Figure 7-3, carefully disconnect the W13 cable at A3J15. Figure 7-3 A3 Digital I.F. Cables Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 257 If the 22.5 MHz signal is within tolerance, carefully reconnect the W13 cable. You should hear a distinct snap when reconnecting the W13 cable. If this cable is not installed properly, intermittent signal fluctuations may occur on the analyzer display. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 258 Use an appropriate cable to go from the SMA connector to the RF input of a functioning spectrum analyzer. 3. Press Freq, 300 MHz, Span, 1 MHz, Amplitude, 10 dBm, Peak Search on the functioning spectrum analyzer. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 259 Reference Assembly troubleshooting section in this service guide. If the 300 MHz L.O. is measuring the correct power level and frequency and the 22.5 MHz signal is low, the most probable cause is the A2 Analog I.F. assembly. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 260: A3 Digital I.f. Assembly Description
— Noise Source Control — Dither for final I.F. — Provides the alignment sequence generator for wide band alignments — Provides wide band Comb Calibration Signal — Trigger interpolation and associated alignment Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 261: A3 Digital I.f. Assembly Theory Of Operation
The signal then passes through a 30 MHz to 90 MHz tripler. A 0 to 5V 30 MHz square wave is generated. Capacitors form a single-pole band pass filter to select the 3rd harmonic, 90 MHz. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 262 Messenger or LVDS. The implementation on the Digital IF is unidirectional, meaning it can only source data, not receive it. Common mode filtering is required to translate the digital ground referenced signals to analog ground at the rear panel. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 263: A3 Digital I.f. Troubleshooting
The marker readout should be 50 MHz at −25 dBm ± 3 dBm. If this reference signal is measuring incorrectly, see Chapter 4, “RF Section Troubleshooting (N8973B, 74B, 75B Analyzers)”, on page 133 in this service guide. 8. To continue verifying press FREQ, Zero Span. Verify the input attenuator on the analyzer is set to 10 dB.
Page 264 Use an appropriate cable to go from the SMA connector to the RF input of a functioning spectrum analyzer. 11.Press Freq, 22.5 MHz Span, 1 MHz, Peak Search on the functioning spectrum analyzer. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 265 The marker readout should be 50 MHz at −25 dBm ± 3 dBm. If this reference signal is measuring incorrectly, see Chapter 4, “RF Section Troubleshooting (N8973B, 74B, 75B Analyzers)”, on page 133 in this service guide. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 266 Use an appropriate cable to go from the SMA connector to the RF input of a functioning spectrum analyzer. 11.Press Freq, 10 MHz, Span, 1 MHz, Peak Search on the functioning spectrum analyzer. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 267 A3 Digital IF or the A4 CPU. It is difficult to separate these two assemblies given the architecture of the analyzer. Each assembly will have to be tried to see which one is causing the failure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 268 Analog/Digital IF Troubleshooting 25 MHz BW IF Section Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 269: L.o. Synthesizer/Reference Troubleshooting
Keysight NFA Series Noise Figure Analyzers Service Guide L.O. Synthesizer/Reference Troubleshooting What You Will Find in This Chapter The following information is found in this chapter: A14 L.O. Synthesizer Assembly Description on page 270 A14 L.O. Synthesizer Theory of Operation on page 271 A14 L.O.
Page 270: A14 L.o. Synthesizer Assembly Description
RF Front End Assembly. For more detailed description on the RF Front End Assembly, see Chapter 4, “RF Section Troubleshooting (N8973B, 74B, 75B Analyzers)” in this service guide. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 271: A14 L.o. Synthesizer Theory Of Operation
FM tune port to be formed. It has more than an octave of tuning range with relatively flat tuning sensitivity. — The LO Multiplier is a frequency multiplier with switched filters and amplifiers to produce the required output frequency. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 272: A14 L.o. Synthesizer Troubleshooting
— Measure L.O. Output Frequency. These items can be checked with a functioning spectrum analyzer using cables and connectors that function well up to 10 GHz. Figure 8-1 A14 L.O. Synthesizer Assembly Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 273: Verifying The 4800 Mhz Input Power & Frequency Stability
DS2 and DS3 will illuminate when the W6 cable is removed. This is normal. — Connect A14W6 cable end to the RF input of the functioning spectrum analyzer. Figure 8-2 W4 and W6 Location Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 274 L.O. Synthesizer/Reference Troubleshooting A14 L.O. Synthesizer Troubleshooting — The analyzer marker should read 4800 MHz at +4.5 dBm ± 2 dB as shown in Figure 8-3. Figure 8-3 4800 MHz Wide Span Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 275 — Reconnect the W6 cable to A14J200. Figure 8-4 4800 MHz Narrow Span If the 4800 MHz signal is not measuring the correct power level, see the “A16 Reference Assembly Troubleshooting” section later in this chapter. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 276: Verifying The 1St L.o. Output Power
— Turn on the analyzer and wait for the instrument to complete the boot up process. — If the analyzer is an N8973B, press FREQ, 600 MHz, Zero Span. If the analyzer is an N8974B, 75B, or 76B, press FREQ, 4.2 GHz, Zero Span.
Page 277 LO output expected frequency and power using the functioning spectrum analyzer. Perform the preselector peak or preselector centering on the functioning spectrum analyzer if any of the expected 1st L.O. power levels are not within tolerance. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 278 +16 ± 3 dB 5.8225 +16 ± 3 dB Figure 8-6 (see 2100 7.2225 +16 ± 3 dB 2200 7.3225 +16 ± 3 dB Figure 8-7 (see a. Does not apply to the N8973B. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 279 L.O. Synthesizer/Reference Troubleshooting A14 L.O. Synthesizer Troubleshooting Figure 8-6 5.8225 GHz 1st L.O. Measurement Figure 8-7 7.3225 GHz 1st L.O. Measurement Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 280: A16 Reference Assembly Description
The frequency accuracy of the analyzer is directly tied to the accuracy of the frequency reference that is being used. Diagnostic LEDs monitor the status of the various PLLs on the A16 Reference Assembly. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 281 1st IF to 322.5 MHz 2nd IF 4.8 GHz 1st LO Ref A16J703 2.4 GHz VCXO x 2 A14J4 4GHz reference for Offset Loop, only used in Dual-Loop operation Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 282: A16 Reference Assembly Troubleshooting
If not, the Reference Assembly is the most probable cause provided the power supply is operating correctly. Refer to “A7 Midplane Assembly Troubleshooting” on page 315 if the power supplies are suspect. Figure 8-8 A16 Reference Assembly Figure 8-9 A16 Reference LEDs Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 283 Figure 300 MHz A16J711 300 MHz +10 dBm LO AIF 8-16 100 MHz Ref B A16J716 100 MHz +13 dBm Figure 8-17 Figure 10 MHz Output A16J710 10 MHz +7 dBm 8-18 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 284 L.O. Synthesizer/Reference Troubleshooting A16 Reference Assembly Troubleshooting Figure 8-10 50 MHz Ecal Out Figure 8-11 4.8 GHz 2nd LO Out Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 285 L.O. Synthesizer/Reference Troubleshooting A16 Reference Assembly Troubleshooting Figure 8-12 4.8 GHz 1st LO Ref Out Figure 8-13 50 MHz Ref Out Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 286 L.O. Synthesizer/Reference Troubleshooting A16 Reference Assembly Troubleshooting Figure 8-14 4.8 GHz Ref Out Figure 8-15 2.4 GHz Ref Output Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 287 L.O. Synthesizer/Reference Troubleshooting A16 Reference Assembly Troubleshooting Figure 8-16 300 MHz LO AIF Figure 8-17 100 MHz Ref B Out Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 288 L.O. Synthesizer/Reference Troubleshooting A16 Reference Assembly Troubleshooting Figure 8-18 10 MHz Output Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 289: Diagnostic Leds
Is the 2.4 GHz reference PLL locked? On=Normal (locked) Off=Fault (unlocked) A16A1DS5 Green Is the 2.4 GHz VCXO working? On=Yes (alive) Off=Fault (not alive) A16A1DS6 Yellow When Program Code is loading On=Loading code from EEPROM Off=Ready Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 290 L.O. Synthesizer/Reference Troubleshooting A16 Reference Assembly Troubleshooting Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 291: Cpu/Disk Drive Troubleshooting
Keysight NFA Series Noise Figure Analyzers Service Guide CPU/Disk Drive Troubleshooting What You Will Find in This Chapter The following information is presented in this chapter: 1. Theory of operation of the Processor section. 2. Isolating the cause of a hardware problem by verifying the functionality of assemblies in the Processor section.
Page 292: A4 Processor Description
A4 Processor assembly. When the front panel power switch is pressed the A4 Processor assembly tells the A6 Power Supply assembly to turn on. Once the +12V D, +5.1V D, and +3.35V D supplies are all on and within Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 293: Rear Panel Connectivity
— 1 x High Speed USB 2.0 Host Port — DisplayPort Video Output — VGA Output — SD Memory Card Slot (Accessible only when A5 disk drive is removed) Figure 9-1 A4 Processor Assembly Rear Panel Connectivity Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 294: System Memory
A5 disk drive assembly has been changed and the calibration database needs to be transferred to it. The SD memory card is field replaceable. See Chapter 14, “Replaceable Parts” for the correct replacement part number. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 295: A4 Processor Assembly Troubleshooting
Accessing BIOS Setup Utility To easily navigate the BIOS Setup Utility you will want to have an external USB keyboard connected to the instrument. Then, when the initial Keysight Technologies splash screen is displayed at power-up, press the key on the keyboard specified on the initial boot screen (typically the DEL key).
Page 296: A5 Disk Drive Description
For information on how to backup this data see the “Calibration Data Backup and Restore” section in Chapter 16, “Post-Repair Procedures.”. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 297: Drive Partitioning
Data saved in this partition will not be lost if the Instrument Image Recovery process is run. E.This partition is reserved for Keysight's use. The primary use of the E: partition is for storing of the instrument calibration and alignment data. Do not change or overwrite the files on this partition. This could cause your instrument to not meet specifications, or even to stop functioning properly.
Page 298: Instrument Image Recovery System
The same is true for the instrument calibration database since it resides on the E: partition. To restore the C: drive using the image stored in this recovery partition see the section titled “Disk Drive Recovery Process” on page 300. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 299: A5 Disk Drive Troubleshooting
This procedure will not affect the instrument's calibration or user files. If this does not resolve the boot issue, or the instrument never boots the operating system proceed to the “Disk Drive Recovery Process”. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 300: Disk Drive Recovery Process
Using the Instrument Image Recovery System 1. Make sure the instrument is turned off 2. Turn on the instrument 3. After the "Keysight Technologies" screen is displayed the Windows Boot Manager screen as shown in Figure 9-2 will be displayed for 5 seconds...
Page 301: Replacing The Instrument Disk Drive
If the above two procedures did not resolve the booting issue, the disk drive should be replaced. Please refer to the “Disk Drive” on page 435 replacement section in Chapter 15, “Assembly Replacement Procedures”, on page 389. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 302 CPU/Disk Drive Troubleshooting A5 Disk Drive Troubleshooting Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 303: 10 Power Supply/Midplane Troubleshooting
Keysight NFA Series Noise Figure Analyzers Service Guide 10 Power Supply/Midplane Troubleshooting What You Will Find in This Chapter The following information is found in this chapter: A6 Power Supply Description on page 304 A6 Power Supply Basic Troubleshooting (Cover On) on page 310...
Page 304: A6 Power Supply Description
AC power input connector and then reconnected. The power supply assembly plugs into the A7 Midplane Assembly from the rear of the instrument. (see Figure 10-1.) Figure 10-1 Power Supply and Midplane Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 305: Power Supply Theory Of Operation
DCOM J107/J108 +15V A ACOM J103/J104 -15V A ACOM J105 +9V A ACOM J104 -7V A ACOM J105 +5.2V A ACOM J102 FAN POS FAN NEG J101 FAN NEG FAN POS J101 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 306 PS_TEMP is a read out of the internal temperature of the power supply. PS_FAULT PS_FAULT will be a TTL low level signal to indicate that the supply is experiencing an over voltage, over current, or over temperature condition. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 307 The A6 Power Supply assembly will protect itself by shutting down if it overheats. It will also reset itself with no user interaction after the temperature is reduced by approximately 10 degrees C. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 308 Off input, active low. Used to turn off all non-standby supplies. Fan_P Positive fan power supply. Fan_N Negative fan power supply. +12D 12 Volt Digital power supply. +5.1D 5.1 Volt Digital power supply. +5.1D_Sense Remote sense for +5.1 digital supply. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 309 DCOM_Sense Remote sense for DCOM. PWR_OK Power OK Output. PS_ONn Power supply turn on input, active low. ChassisCOM Power supply outer case. Connected to common ground point inside the power supply. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 310: A6 Power Supply Basic Troubleshooting
If these initial checks are functioning properly and yet the signal analyzer will not boot up properly, or the display is not turning on, refer to Chapter 2, “Boot Up and Initialization Troubleshooting” in this service manual. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 311 If any portion of the boot process fails, Chapter 2 describes a step-by-step troubleshooting procedure to help isolate the root cause of the failure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 312: A7 Midplane Description
If for some reason any of these cannot be remembered by the instrument there could be a problem with this memory and the A7 Midplane board assembly would need to be replaced. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 313 Other circuitry on the A7 Midplane include a circuit to phase lock the CPU clock to the analyzer's 10 MHz reference and a Complex Programmable Logic Device (CPLD) used as an Instrument Local Bus (ILB) buffer to A16 Reference Assembly connector at J21. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 314 A7 Midplane Assembly The L.O. Synthesizer, Front End Control Assembly, Analog IF, and Digital IF plug into the Motherboard. All other assemblies mentioned plug into the Midplane from the rear of the instrument. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 315: A7 Midplane Assembly Troubleshooting
These DC voltages can be verified with a voltmeter. Continuity measurements can also be performed on each power supply if a shorted condition is suspect. Refer to the table below for measurement details. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 316 -15 Volt Analog supply -15 ± 1.0 390 Ω Fan Positive supply 8.5 to 13.5 VDC 490 Ω ~8.8 VDC @ 25C Analog Common TP14 Digital Common TP12 Power OK +3.9 ± 0.75 9.2 kΩ Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 317: 11 Front Panel/Motherboard Troubleshooting
Keysight NFA Series Noise Figure Analyzers Service Guide 11 Front Panel/Motherboard Troubleshooting What You Will Find in This Chapter The following information is found in this chapter: A8 Motherboard Description on page 318 A1 Front Panel Assembly on page 320...
Page 318: A8 Motherboard Description
— Circuitry for fan speed control — 10 MHz Reference distribution Figure 11-1 Motherboard The Motherboard is a horizontally mounted, located near the bottom of the analyzer. The Motherboard has the following connector types: Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 319: A8 Motherboard Troubleshooting
B1, Fan #1 A14, L.O. Synthesizer Front Panel A15, Front End Control A8 Motherboard Troubleshooting There are no troubleshooting procedures for this assembly. If the Motherboard is suspect, it must be replaced. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 320: A1 Front Panel Assembly
USB connectors and the keyboard microcontroller. A1A3 LCD The LCD used is a 10.6 inch WXGA TFT touchscreen display, which as a resolution of 1280 x 768. It has two backlights that are not individually replaceable. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 321: What You Will Find In This Chapter
Keysight NFA Series Noise Figure Analyzers Service Guide 12 Block Diagrams What You Will Find in This Chapter The following sections are found in this chapter: RF Lowband Path Block Diagram on page 323 RF Highband Path #1 Block Diagram on page 324...
Page 322: Block Diagrams
Block Diagrams Block Diagrams Block Diagrams Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 323: Rf Lowband Path Block Diagram
N8973B, 74B, 75B NFA RF BLOCK DIAGRAM (Lowband Path - Input signals < 3.6 GHz) A15 FRONT END CONTROLLER J800 ATTENUATOR CONTROL J700 LOW BAND SWITCH CONTROL J300 J302 PRESELECTOR DRIVER CONTROL A12 YTF J900 P/O Enhanced to AIF Front End 322.5 MHz...
Page 324: Rf Highband Path #1 Block Diagram
N8974B, 75B NFA RF BLOCK DIAGRAM (Highband Path #1 - Input signals 3.6 GHz to 13.6 GHz) A15 FRONT END CONTROLLER J800 ATTENUATOR CONTROL J700 LOW BAND SWITCH CONTROL J300 J302 PRESELECTOR DRIVER CONTROL A12 YTF J900 P/O Enhanced to AIF Front End 322.5 MHz -33 dBm...
Page 325: Rf Highband Path #2 Block Diagram
N8975B NFA RF BLOCK DIAGRAM (Highband Path #2 - Input signals 13.6 GHz to 26.5 GHz) A15 FRONT END CONTROLLER J800 ATTENUATOR CONTROL J700 LOW BAND SWITCH CONTROL J300 J302 PRESELECTOR DRIVER CONTROL A12 YTF J900 P/O Enhanced to AIF Front End 322.5 MHz -19 dBm...
Page 326: N8976B Rf (Low Freq) Block Diagram
N8976B NFA RF BLOCK DIAGRAM (Lowband Path - Input signals < 3.6 GHz) A15 FRONT END CONTROLLER J800 ATTENUATOR CONTROL J700 LOW BAND SWITCH CONTROL J300 J302 PRESELECTOR DRIVER CONTROL A12 YTF J900 to AIF 322.5 MHz 23 dBm Preselector J901 Burst A11 LOWBAND...
Page 327: N8976B Rf (Highband Path #1) Block Diagram
N8976B NFA RF BLOCK DIAGRAM (Highband Path #1 - Input signals 3.6 to 17.1 GHz) A15 FRONT END CONTROLLER J800 ATTENUATOR CONTROL J700 LOW BAND SWITCH CONTROL J300 J302 PRESELECTOR DRIVER CONTROL A12 YTF J900 to AIF 322.5 MHz 35 dBm Preselector J901 Burst...
Page 328: N8976B Rf (Highband Path #2) Block Diagram
N8976B NFA RF BLOCK DIAGRAM (Highband Path #2 - Input signals 17.1 to 34.5 GHz) A15 FRONT END CONTROLLER J800 ATTENUATOR CONTROL J700 LOW BAND SWITCH CONTROL J300 J302 PRESELECTOR DRIVER CONTROL A12 YTF J900 to AIF 322.5 MHz 32 dBm Preselector J901 Burst...
Page 329: N8976B Rf (Highband Path #3) Block Diagram
N8976B NFA RF BLOCK DIAGRAM (Highband Path #3 - Input signals 34.5 to 44 GHz) A15 FRONT END CONTROLLER J800 ATTENUATOR CONTROL J700 LOW BAND SWITCH CONTROL J300 J302 PRESELECTOR DRIVER CONTROL A12 YTF J900 to AIF 322.5 MHz 36 dBm Preselector J901 Burst...
Page 330: Reference And Synthesizer Block Diagram
REFERENCE and SYNTHESIZER BLOCK DIAGRAM To A13J1 A16 REFERENCE A14 LO SYNTHESIZER A16A1 REFERENCE DAUGHTER 571 MHz to 4.8 GHz Serial Bus 1154 MHz 2nd LO FPGA FRAC-N (from A8) Symv/Int_Swp J702 4800 MHz CONTROLLER 2nd LO CONTROLLER J200 J703 2nd LO 2400 MHz 2400 MHz...
Page 331: 25 Mhz Bandwidth I.f. System Block Diagram
25 MHz BW IF SYSTEM BLOCK DIAGRAM A3 DIGITAL IF 10 MHz 10 MHz OUT From (BNC) A16J710 From A13J7 Capture IF 10 MHz REF Memory 10 MHz LVDS NOISE SOURCE To A3 DRIVE +28V Noise (BNC) 300 kHz/800 kHz A2 ANALOG IF Source 12 MHz...
Page 332: Nfa Computer Block Diagram
Block Diagrams Block Diagrams NFA Computer Block Diagram Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 333: 13 Service And Diagnostics Menus
System Settings Diagnostic menu and Spectrum Analyzer mode Measure Setup menu. The Service capabilities are intended for field service technicians. These technicians may be at a Keysight Service Center or at a self-maintaining customer site. There are two types of Service capabilities: 1.
Page 334: Controlling Access
2. “Secure service access” to the Service menu. This prevents the casual user from accessing and using these features. It is intended to provide this access to Keysight Service Centers or any customer who purchases the Service Guide. The “Service Functions” type of Service capability is defined above.
Page 335: Secure Service Access
At this point you will see the window shown in Figure 13-1. Enter the Service Code and press Login. The Service Code is: -2061 Figure 13-1 Service Code Entry Figure 13-2 Secure Service Menus (Accessed via System->Service) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 336 Service and Diagnostics Menus Overview Figure 13-3 Lock and LO (Accessed via Spectrum Analyzer Mode -> Meas Setup -> Lock and LO) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 337 Service and Diagnostics Menus Overview Figure 13-4 Diagnostics (Hardware Statistics) (Accessed via System -> Diagnostics) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 338 Service and Diagnostics Menus Overview Figure 13-5 Service Diagnostics (Corrections Menu) (Accessed via Spectrum Analyzer Mode -> Meas Setup -> Service Diagnostics) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 339: Service Key Descriptions
The adjustment is performed by changing the DAC setting controlling the reference. Once the reference is adjusted to the proper frequency, the DAC value can be saved in non-volatile memory by pressing the Save menu key. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 340: Alignments
The Advisory Event “Alignment complete” is displayed when the alignment is complete. Align LO can be interrupted by pressing the Cancel (ESC) front-panel key. When this occurs, no new LO alignment data will be employed. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 341 The Advisory Event “Alignment complete” is displayed when the alignment is complete. Align IF can be interrupted by pressing the Cancel (ESC) front-panel key. When this occurs, no new IF alignment data will be employed. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 342 The instrument will stop any measurement currently underway, perform the alignment, and then restart the measurement from the beginning (similar to pressing the Restart key). Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 343 Service and Diagnostics Menus Service Key Descriptions Show Software The Show Software screen displays revision information for Keysight internal software that comprises the embedded application and programmable hardware devices (FPGAs and PLDs). Figure 13-6 Show Software Screen Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 344: Corrections
The example spectrum below shows the effect of turning off RF Flatness Video. The yellow trace shows RF Flatness Video shift on, and the Blue trace shows RF Flatness Video shift off. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 345 ON/OFF to control the IQ alignment.) When Snapshot Alignments are OFF, the Advisory Event “Snapshot OFF” will be displayed. When Snapshot Alignments are ON, the Advisory Event “Snapshot OFF” will be cleared. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 346: Band Lock
Locks the analyzer to Band 1. Locks the analyzer to Band 2. Locks the analyzer to Band 3. Locks the analyzer to Band 4. Locks the analyzer to Band 5. Locks the analyzer to Band 6. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 347: Lo Band Lock
Locks the analyzer to LO Band 0. Band 1 Locks the analyzer to LO Band 1. Band 2 Locks the analyzer to LO Band 2. Band 3 Locks the analyzer to LO Band 3. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 348: Lo Control
EXT MIXER connector. External LO Turnoff Disconnects the 1st LO path which will minimize the effect of the 1st LO signal at the front panel EXT MIXER connector. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 349: Front Panel Key Test
The screen will display a series of lines. For each blue line, trace along the line with your finger to draw a matching line. Lines that deviate significantly from the blue trace line (i.e beyond the gray lines) will be marked in red. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 350 Service and Diagnostics Menus Front Panel Key Test Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 351: 14 Replaceable Parts
Figure 14-7, “Top Brace,” Figure 14-8, “RF Area - N8973B, 74B, 75B,” Figure 14-9, “RF Area - Millimeter Wave Instruments, N8976B,” Figure 14-10, “Front End Parts - N8973B, 74B, 75B,” Figure 14-11, “Front End Parts - N8976B,” Figure 14-12, “Front End Control Cables,”...
Page 352: How To Order Parts
— Description of where the part is located, what it looks like, and its function (if known) — Quantity required For a list of Keysight Technologies sales and service office locations, refer to “Contacting Keysight Technologies” on page Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 353: Replaceable Parts
Overlay, left for CXA TG Output N9020-80166 Overlay, BBIQ Bottom N9020-80163 Overlay, BBIQ top A1A2 Front Panel Control Board N9020-63274 A1A3 Liquid Crystal Display 10.6-in w/PCAP Touch 1280X768-Pixels 2090-1103 A1A4 Keyboard, PCA N9020-63294 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 354 Disk Drive Interconnect Board W1312-63079 A4A2 Memory card, SD 1819-1069 A4BT1 CPU Board Battery (CR2032) 1420-0356 Disk Drive Replacement Kit N9020-60202 A5MP1 W1312-40078 Disk Drive Tray A5MP2 W1312-00103 Disk Drive Rear Panel Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 355 Power Supply 0950-5012 Midplane Assembly N9020-63120 Motherboard Assembly N9000-66404 RF Attenuator A 0 to 4 dB (N8973B, 74B, 75B) 33360-60008 0 to 10 dB (N8976B) 33326-60013 RF Attenuator B 0 to 66 dB (N8973B, 74B, 75B) 33321-60083 0 to 60 dB (N8976B)
Page 356 N9020-60098 N8976B N9020-60172 Reference Assembly N9020-60200 B1-B2 3160-4199 Type-N (f) RF Input Connector Assembly (N8973B, 74B, 75B) 5002-0702 2.4 mm (m) Input Connector Assembly (N8976B) N9030-60011 EMI O-Ring 18.75 mm ID 8160-1637 (used between RF Input Connector and Front Frame)
Page 357 Strap Handle Plugs (Option PRC, Portable Configuration) N9020-40014 MP65 Reserved MP66-69 Bottom Feet (Benchtop Configuration) 5041-7906 MP70-71 Tilt Stands (Benchtop Configuration) 1460-1345 MP72-75 Bottom Feet Key Locks (Benchtop Configuration) 5021-2840 MP77 Reserved Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 358 N8973B, 74B, 75B N9020-20123 N8976B N9010-20005 Cable Assembly, A10 Output to A11J1 (semi-rigid) N8973B, 74B, 75B N9020-20153 N8976B N9010-20004 Cable Assembly, J1 to A9 Input (semi-rigid) N8973B, 74B, 75B N9020-20141 N8976B N9020-20133 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 359 Cable Assembly, A15J1100 to Rear Panel Port 9 (Flexible Coax) 8121-2028 Cable Assembly,A13J6 to A3J17 (Flexible Coax) 8121-1940 Cable Assembly, A2J601 to A3J19 (Flexible Coax) 8120-8868 Cable Assembly, A16J706 to A3J14 (Flexible Coax) 8121-1401 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 360 Front panel protective cover p/n N9020-40004 is optimized only for use on analyzers with the porta- ble configuration, Opt PRC. Although the cover will fit on analyzers with the benchtop configuration, its use on benchtop configurations is not recommended. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 361 Display Bracket 0515-1934 M2.5 X 0.45 Torx T-8 5 inch-lbs (6 mm long) Display Bracket & Front Front Frame 0515-0372 M3 X 0.5 Torx T-10 9 inch-lbs Panel (8 mm long) Interface/Speaker Bracket Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 362 Bracket (8 mm long) Midplane Assembly Midplane Bracket 0515-0375 M3 X 0.5 Torx T-10 9 inch-lbs (16 mm long) Motherboard Chassis Base 0515-0372 M3 X0.5 Torx T-10 9 inch-lbs (8 mm long) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 363 (6 mm long) Top Brace Chassis Components 0515-0372 M3 X 0.5 Torx T-10 9 inch-lbs (8 mm long) YTF Preselector Chassis 0515-0372 M3 X 0.5 Torx T-10 9 inch-lbs (except (8 mm long) N8973B) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 364: Hardware
CPU Replacement Kit (w/o disk drive) N9020-60247 A6 Power Supply 0950-5012 A16 Reference Assembly N9020-60200 A14 L.O. Synthesizer Assembly N9020-60118 A15 Front End Control Assembly Refer to Table 14-1 A7 Midplane Assembly N9020-63120 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 365 MP21-22 Strap Handles (Benchtop N9020-60252 Configuration) (includes screws) Screw M4 X 0.7 (25 mm long) 0515-1619 MP17-20 Rear Feet (Benchtop Configuration) 5041-7903 MP16 Dress Cover (includes magnetic gasket N9010-00002 and snaps) MP86 Accessory pouch N9010-60014 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 366 M4 X 0.7 (14 mm long) 0515-0435 MP41-44 Front Bumpers (Option PRC, Portable N9020-40016 Configuration) MP61-64 Strap Handle Plugs (Option PRC, Portable N9020-40014 Configuration) Screw M5 X 0.8 (14 mm long) 0515-5209 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 367 Item Description Keysight Part Number Screw M4 X 0.7 (25 mm long) 0515-1619 MP45-48 Rear Bumpers (Option PRC, Portable N9020-40015 Configuration) (includes screws) MP16 Dress Cover (includes magnetic gasket N9010-00002 and snaps) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 368 CPU Assembly Table 14-7 Item Description Keysight Part Number CPU Replacement Kit N9020-60202 A4BT1 CPU Board Battery (CR2032) 1420-0356 A4A1 Disk Drive Interconnect Board W1312-63079 Screw M3 x 0.5 (8 mm long) 0515-0372 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 369 (For rev 6 and earlier of drive tray. For rev 7 and later, use 0515-1035 M3 (8 mm Flat-HD)) Screw M2.5 x 0.45 (5 mm long) 0515-2219 Screw M3 x 0.5 (6 mm long) 0515-1946 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 370 Keysight Part Number MP7 Top Brace (includes foam strips) N9020-60018 Screw M3 X 0.5 (8 mm long) 0515-0372 Screw M3 X 0.5 (6 mm long) 0515-1946 Screw M3 X 0.5 (8 mm long) 0515-0372 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 371 A9 RF Attenuator A 33360-60008 A10 RF Attenuator B 33321-60083 A11 Low Band Switch Assembly E4410-60121 A12 YTF Preselector (not used in N8973B) 5087-7382 Cable Assembly, A11J2 to A13J2 (semi-rigid) N9020-20101 Cable Assembly, A12 Output to A13J9 (semi-rigid) N9020-20124 Cable Assembly, A11J3 to A12 Input (semi-rigid)
Page 372 A9 RF Attenuator A 33326-60013 A10 RF Attenuator B 33325-60020 A11 Low Band Switch Assembly N9020-60051 A12 YTF Preselector (not used in N8973B) 5087-7383 Cable Assembly, A11J2 to A13J2 (semi-rigid) N9020-20131 Cable Assembly, A12 Output to A13J9 (semi-rigid) N9010-20006 Cable Assembly, A11J3 to A12 Input (semi-rigid)
Page 373 A13W2 Cable Assembly, A13J10 to A13A1 Input (semi-rigid) N9020-20231 A12 YTF Preselector (not used in N8973B) 5087-7382 J1 Type-N (f) RF Input Connector Assembly (N8973B, 74B, 75B) 5002-0702 A11 Low Band Switch Assembly E4410-60121 Cable Assembly, A11J2 to A13J2 (semi-rigid)
Page 374 Cable Assembly, J1 to A9 Input (semi-rigid) N9020-20141 Cable Assembly, A13J7 to A2J100 (Flexible Coax) 8121-1400 Cable Assembly, A13J12 to A15J102 (Ribbon Cable) E4410-60156 Cable Assembly, A13J6 to A16J705 (Flexible Coax) 8121-1400 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 375 Cable Assembly, A13J10 to A13A1 Input (semi-rigid) N9020-20229 A13W2 Cable Assembly, A13J10 to A13A1 Input (semi-rigid) N9020-20046 A12 YTF Preselector (not used in N8973B) 5087-7383 J1 2.4 mm (m) Input Connector Assembly (N8976B) N9030-60011 A11 Low Band Switch Assembly N9020-60051...
Page 376 Cable Assembly, J1 to A9 Input (semi-rigid) N9020-20133 Cable Assembly, A13J7 to A2J100 (Flexible Coax) 8121-1400 Cable Assembly, A13J12 to A15J102 (Ribbon Cable) E4410-60156 Cable Assembly, A13J6 to A16J705 (Flexible Coax) 8121-1400 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 377 Cable Assembly, A9 & A10 to A15J800 (Ribbon Cable) E4410-60157 Cable Assembly, A13J12 to A15J102 (Ribbon Cable) E4410-60156 Cable Assembly, A11J4 to A15J700 (Ribbon Cable) Refer to Table 14-1 Cable Assembly, A15J300 to A12J1 (Wire Harness) N9020-60059 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 378 Cable Assembly, A16J701 to A9 Cal Signal Input/Port 2 Refer to Table 14-1 (semi-rigid) Cable Assembly, A13J6 to A16J705 (Flexible Coax) 8121-1400 Cable Assembly, Ext. Reference Cable (rear frame) to A16J704 8121-1402 (Flexible Coax) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 379 Replaceable Parts Hardware Figure 14-14 AIF/DIF Cables - Standard Instruments Figure 14-15 AIF/DIF Cables, bottom - Standard Instruments Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 380 Cable Assembly, A16J710 to A3J14 (Flexible Coax) 8121-1401 Cable Assembly, A2J601 to A3J15 (Flexible Coax) 8121-1411 Cable Assembly, A16J711 to A2J300 (Flexible Coax) 8121-1401 Cable Assembly, A13J7 to A2J100 (Flexible Coax) 8121-1400 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 381 A2 Analog I.F. Assembly N9020-60011 A3 Digital I.F. Assembly N9020-60119 Screw, M3 X 0.5 (8 mm long) 0515-0372 Cable, Interconnect from A2J820 to A3J20 N9020-60046 A3W1 Cable Assembly, Smart Noise Source (Wire Harness) E4410-60163 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 382 W1312-00137 Chassis Side, Right (Outer, attaches to Low Band Switch bracket, N9020-00034 Attenuator brackets, and Chassis bottom) Rear Panel Replacement Kit (includes foam strip) N9020-60298 MP36-37 Attenuator Bracket Refer to Table 14-1 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 383 Replaceable Parts Hardware Figure 14-18 Motherboard Table 14-19 Item Description Keysight Part Number A8 Motherboard Assembly N9000-66404 Screw M3 X0.5 (8 mm long) 0515-0372 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 384 Replaceable Parts Hardware Figure 14-19 Fan Hardware Table 14-20 Item Description Keysight Part Number 3160-4199 3160-4199 MP25-26 Fan Guard 3160-0281 MP27-34 Rivet, Fan Mounting (8 pieces) 0361-1272 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 385 Connector and Front Frame) Screw M3 X 0.5 (8 mm long) 0515-0372 Cable Assembly, J1 to A9 Input (semi-rigid) N8973B, 74B, 75B N9020-20141 N8976B N9020-20133 MP83 Gusset, Chassis (near RF Input connector) W1312-00093 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 386 A1MP10 Bracket front panel shield N9020-00064 A1A2 Front Panel Control Board N9020-63274 A1MP11 Display Bracket, Front Panel N9020-00078 A1W1 Flex Circuit, Display to Front Panel Control Board N9020-60273 A1W2 Cable Assembly, Backlight N9020-60217 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 387 Replaceable Parts Hardware Figure 14-22 Front Frame Exploded View Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 388 A1W1 Flex Circuit, Display to Front Panel Control Board N9020-60273 A1W2 Cable Assembly, Backlight N9020-60217 A1MP14 Shield N9020-00066 W1 Cable, Front Panel Interface Board to Motherboard N9020-60216 (Ribbon) a. Non-orderable item, see A1A1. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 389: 15 Assembly Replacement Procedures
“Top Brace” on page 398 “RF Area (N8973B, 74B, 75B)” on page 399 “RF Area (N8976B)” on page 409 “RF Front End Assembly (N8973B, 74B, 75B)” on page 420 “RF Front End Assembly (N8976B)” on page 422 “Front End Control Assembly” on page 424 “L.O.
Page 390: Before Starting
Failure to heed the safety precautions can result in severe or fatal injury. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 391: Tools You Will Need
Adjustments Tests after an instrument repair Refer to Table 16-1 on page 473 for information about post-repair procedures. If one or more instrument assemblies have been repaired or replaced, perform the related adjustments and performance verification tests. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 392: Major Assembly Locations
Table 15-2 Item Description A2 Analog I.F. Assembly/A3 Digital I.F. Assembly A4 CPU Assembly A6 Power Supply A16 Reference Assembly A14 L.O. Synthesizer Assembly A15 Front End Control Assembly A7 Midplane Assembly Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 393: Instrument Outer Case
3. Using the T-20 driver, remove the four screws (including washers) (3) (two on each side) that hold the rear feet (4) (two on each side) in place. 4. Pull the instrument cover (5) off towards the rear of the instrument. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 394 3. Replace the four rear feet to the rear of the instrument (two on each side). Torque the rear feet screws to 21 inch pounds. 4. Replace the handle straps on both sides of the instrument. Torque the handle strap screws to 21 inch pounds. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 395: Option Prc
(1) that hold the bail handle (2) to the front frame. Figure 15-4 Bail Handle Removal 2. Using the T-20 driver, remove the four screws (two on each side) (6) that hold the strap handle plugs (5) in place. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 396 (1) that hold the rear bumpers (2) (two on each side) in place. Figure 15-5 Option PRC Instrument Outer Case Removal 4. Pull the instrument cover (3) off towards the rear of the instrument. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 397 (2) to the front frame. Torque to 21 inch pounds. 5. Refer to Figure 15-5. Replace the four rear bumpers to the rear of the instrument. Torque to 21 inch pounds. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 398: Top Brace
Top Brace to the chassis and boards. Figure 15-6 Top Brace Removal Replacement 1. Refer to Figure 15-6. To replace the Top Brace place it into the correct position and attach the appropriate screws. Torque to 9 inch-pounds. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 399: Rf Area (N8973B, 74B, 75B)
15-7. The RF area consists of RF attenuator A (1), RF attenuator B (2), low band switch assembly (3), and YTF Preselector (4). The YTF Preselector is not typically installed on the N8973B. Figure 15-7 RF Area Components and Cables...
Page 400 3. Remove the front panel. Refer to the “Front Frame Assembly” removal procedure. 4. Refer to Figure 15-8. Remove the chassis side, right (1) by removing the thirteen screws (2) using the T-10 driver. Figure 15-8 RF Bracket Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 401: Low Band Switch - Standard Rf/Microwave Instruments
2. Remove the semi-rigid cables W3, W8, and W9 using the 5/16 inch wrench. W8 will not be present on the N8973B. 3. Remove the two screws (2) using the T-10 driver. The low band switch (1) can now be removed from the chassis.
Page 402 RF Area (N8973B, 74B, 75B) 4. Refer to Figure 15-10. To separate the switch from the bracket, remove the four screws (3) using the T-10 driver. Figure 15-10 Low Band Switch and Bracket Separation Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 403 3. Refer to Figure 15-9. Replace the semi-rigid cables W3, W8, and W9. Torque to 10 inch-pounds. W8 will not be present on the N8973B. 4. Replace the ribbon cable W18. 5. Refer to Figure 15-8. Position the chassis side, right onto the chassis and replace the thirteen screws.
Page 404: Attenuators - Rf/Microwave Instruments
3. Remove the two screws (3) or (4) for each attenuator bracket to remove from the chassis using the T-10 driver. 4. Remove the two screws to separate the attenuator from the bracket. Figure 15-11 Attenuators Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 405 3. Position the attenuator and bracket into the chassis and attach with the two screws. Torque to 9 inch-pounds. 4. Replace the ribbon cable and semi-rigid cables W9, W10, W11 and W19 to the attenuator. Torque the semi-rigid cables to 10 inch-pounds. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 406: Ytf Preselector - Rf/Microwave Instruments
YTF Preselector - RF/Microwave Instruments Removal 1. Refer to Figure 15-12. Remove cables W7 and W8 from the YTF Preselector (1). Figure 15-12 YTF Preselector Removal 2. Remove the wire harness W22. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 407 RF Area (N8973B, 74B, 75B) 3. Refer to Figure 15-13. From the bottom of the instrument, remove the four screws (2). The YTF Preselector can now be removed from the chassis. Figure 15-13 YTF Preselector Screws Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 408 7. Replace the front panel. Refer to the “Front Frame Assembly” replacement procedure. 8. Replace the top brace. Refer to the “Top Brace” replacement procedure. 9. Replace the instrument outer case. Refer to the “Instrument Outer Case” replacement procedure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 409: Rf Area (N8976B)
15-15. The RF area consists of RF attenuator A (1), RF attenuator B (2), low band switch assembly (3), and YTF Preselector (4). Figure 15-15 RF Area Components and Cables - N8976B Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 410 12.Remove the front panel. Refer to the Front Frame Assembly removal procedure. 13.Refer to Figure 15-16. Remove the chassis side, right (1) by removing the thirteen screws (2) using the T-10 driver. Figure 15-16 RF Bracket Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 411: Low Band Switch
3. Remove the two screws (2) using the T-10 driver. The low band switch and bracket (1) can now be removed from the chassis. Figure 15-17 Low Band Switch Cable Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 412 Assembly Replacement Procedures RF Area (N8976B) Figure 15-18 Low Band Switch Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 413 RF Area (N8976B) 4. Refer to Figure 15-19. To separate the switch from the bracket, remove the five screws (3) using the T-10 driver. Figure 15-19 Low Band Switch and Bracket Separation Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 414 6. Replace the front panel. Refer to the Front Frame Assembly replacement procedure. 7. Replace the top brace. Refer to the Top Brace replacement procedure. 8. Replace the instrument outer case. Refer to the Instrument Outer Case replacement procedure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 415: Attenuators
3. Remove the two screws (3) or (4) for each attenuator bracket to remove from the chassis using the T-10 driver. 4. Remove the two screws to separate the attenuator from the bracket. Figure 15-20 Attenuators Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 416 3. Position the attenuator and bracket into the chassis and attach with the two screws. Torque to 9 inch-pounds. 4. Replace the ribbon cable and semi-rigid cables W9, W10, W11 and W19 to the attenuator. Torque the semi-rigid cables to 10 inch-pounds. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 417: Ytf Preselector
RF Area (N8976B) YTF Preselector Removal 1. Refer to Figure 15-21. Remove cables W7 and W8 from the YTF Preselector (1). Figure 15-21 YTF Preselector Removal 2. Remove the wire harness W22. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 418 RF Area (N8976B) 3. Refer to Figure 15-22. From the bottom of the instrument, remove the four screws (2). The YTF Preselector can now be removed from the chassis. Figure 15-22 YTF Preselector Screws Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 419 6. Replace the front panel. Refer to the Front Frame Assembly replacement procedure. 7. Replace the top brace. Refer to the Top Brace replacement procedure. 8. Replace the instrument outer case. Refer to the Instrument Outer Case replacement procedure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 420: Rf Front End Assembly (N8973B, 74B, 75B)
W4, W5, W7, W15 or W36, and W20 attached to the RF Front End Assembly (1). W7 will not be present on the N8973B. 5. Remove the ribbon cable W17 from the RF Front End Assembly. 6. Remove the four screws (2) using the T-10 driver. The RF Front End Assembly can now be removed from the chassis.
Page 421: Replacement
3. Reattach the cables W3, W4, W5, W7, W15 or W36, and W20 to the RF Front End Assembly (1). Torque the semi-rigid cables to 10 inch-pounds. W7 will not be present on the N8973B. 4. Replace the front panel. Refer to the “Front Frame Assembly”...
Page 422: Rf Front End Assembly (N8976B)
5. Remove the ribbon cable W17 from the RF Front End Assembly. 6. Remove the four screws (2) using the T-10 driver. The RF Front End Assembly can now be removed from the chassis. Figure 15-25 RF Front End Assembly (N8976B) Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 423: Replacement
Front Frame Assembly replacement procedure. 5. Replace the instrument top brace. Refer to the Top Brace replacement procedure. 6. Replace the instrument outer case. Refer to the Instrument Outer Case replacement procedure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 424: Front End Control Assembly
15-26. Remove the ribbon cables W16, W17, and W18 and the wire harness W22 from the Front End Control assembly (1). W22 will not be present on the N8973B. N8976B will have the Enhanced Front End Control Assembly which will...
Page 425 Assembly Replacement Procedures Front End Control Assembly Figure 15-26 Front End Control Assembly Removal Figure 15-27 Enhanced Front End Control Assembly Cables Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 426: Replacement
W22 to the Front End Control assembly (1). If the instrument has the Enhanced Front End Control Assembly, reattach the additional cables as shown in.Figure 15-27. W22 will not be present on the N8973B. 3. Replace the instrument top brace. Refer to the “Top Brace” replacement procedure.
Page 427: L.o. Synthesizer Assembly
2. Reattach the cables W4 and W6 to the L.O. Synthesizer assembly (1). Torque to 10 inch-pounds. 3. Replace the instrument top brace. Refer to the “Top Brace” replacement procedure. 4. Replace the instrument outer case. Refer to the “Instrument Outer Case” replacement procedure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 428: Rear Panel
15-29. Place the rear panel (1) into position in the chassis. Replace the twenty screws (2) to attach the rear panel to the chassis. Torque to 9 inch-pounds. 3. Replace the instrument outer case. Refer to the “Instrument Outer Case” replacement procedure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 429: Reference Assembly
4. Refer to Figure 15-30. Remove cables W5, W6, W12, W14, W19, W20, and W23 from the reference assembly (1). Use the 5/16 inch wrench where necessary. Figure 15-30 Reference Board Cables Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 430: Replacement
4. Replace the rear panel. Refer to the “Rear Panel” replacement procedure. 5. Replace the top brace. Refer to the “Top Brace” replacement procedure. 6. Replace the instrument outer case. Refer to the “Instrument Outer Case” replacement procedure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 431: Power Supply Assembly
15-32. Remove the three screws (1) attaching the power supply (2) to the power supply bracket (3). 7. The power supply assembly can be removed from the chassis by pulling straight out the back. Figure 15-32 Power Supply Assembly Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 432: Replacement
5. Replace the top brace and reference bracket. Refer to the “Top Brace” replacement procedure. 6. Replace the rear panel. Refer to the “Rear Panel” replacement procedure. 7. Replace the instrument outer case. Refer to the “Instrument Outer Case” replacement procedure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 433: Cpu Assembly
Use the two ejectors to pull the CPU assembly out from the chassis. If the A4BT1 CPU board battery was changed, refer to Chapter 16, “Post-Repair Procedures.” for setup instructions. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 434: Replacement
Secure the board with the ejectors. 2. Refer to Figure 15-34. Replace the six screws (1) that attach the CPU assembly to the chassis. Torque to 9 inch-pounds. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 435: A5 Solid State Drive
CPU assembly from the chassis. Disk Drive Removal 1. Refer to Figure 15-35. Loosen the thumb screw (2) and pull the SSD (1) out of the CPU assembly. Figure 15-35 SSD Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 436 15-35. Slide the SSD into the CPU assembly and push to mate the connector. Secure the thumb screw to 9 inch-pounds. Refer to Chapter 16, “Post-Repair Procedures.” and perform all of the specified tasks for replacing the A5 Disk Drive assembly. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 437: A4A1 Cpu Memory Card
19 flat-head screws (2) and 3 pan-head screws (3). The 19 flat-head screws need to be discarded and replaced since they are precoated with a thread locking compound and new screws will need to be used when the cover is re-installed. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 438 (5) to the A4 CPU assembly. 5. Unplug and remove the A4A1 Disk Drive Interconnect board from the A4 CPU assembly by carefully sliding the board out towards the disk drive bay opening (6). Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 439 4. Re-install the A4 CPU assembly into the instrument. Refer to the CPU Assembly installation procedure. 5. Re-install the A5 Disk Drive assembly into the instrument. Refer to the Disk Drive installation procedure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 440: Analog I.f. (Aif)/Digital I.f. (Dif) Assembly
“Rear Panel” removal procedure. 3. Refer to Figure 15-39. Depending on the installed options, remove the appropriate cables from the bottom of the DIF assembly. Figure 15-39 W12, W13 Removal - Standard Instruments Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 441 Remove cables W13 or W41, W14, and W15 or W37 from the AIF assembly. 5. The AIF/DIF assembly can be removed from the chassis by pulling straight out the back. Figure 15-40 AIF/DIF Assembly Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 442: Separate Aif/Dif Assembly
1. Set the DIF in position over the AIF. Reinstall the three screws removed before. Torque to 9 inch-pounds, starting with the middle screw. 2. To reconnect the AIF and the DIF, reconnect the ribbon cable W2. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 443: Replacement
15-39. Replace the appropriate cables to the bottom of the DIF assembly. 4. Replace the rear panel. Refer to the “Rear Panel” replacement procedure. 5. Replace the instrument outer case. Refer to the “Instrument Outer Case” replacement procedure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 444: Midplane Assembly
6. Remove the power supply assembly. Refer to the “Power Supply Assembly” removal procedure. 7. Refer to Figure 15-42. Remove the power supply support bracket (1) by removing the two screws (2). Figure 15-42 Power Supply Bracket Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 445 15-43. Remove the six screws (2) attaching the midplane assembly (1) to the midplane bracket. The midplane assembly can now be pulled up from the chassis by leveraging up on the ejectors. Figure 15-43 Midplane Assembly Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 446: Replacement
6. Replace the top brace and reference bracket. Refer to the “Top Brace” replacement procedure. 7. Replace the rear panel. Refer to the “Rear Panel” replacement procedure. 8. Replace the instrument outer case. Refer to the “Instrument Outer Case” replacement procedure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 447: Motherboard Assembly
13.Remove the fan assembly. Refer to the “Fan Assembly” removal procedure. 14.Refer to Figure 15-44 Figure 15-45. Remove the midplane bracket (1) by removing the eight screws (2) (two on each side and four on the bottom). Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 448 Assembly Replacement Procedures Motherboard Assembly Figure 15-44 Midplane Bracket Removal Figure 15-45 Bottom Screws Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 449 Assembly Replacement Procedures Motherboard Assembly 15.Refer to Figure 15-46. Remove the left side chassis (same side as the fan) by removing the seven screws (four on the bottom). Figure 15-46 Chassis Side Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 450: Replacement
(2). Torque to 9 inch-pounds. 4. Replace the fan assembly. Refer to the Fan Assemblyreplacement procedure. 5. Replace the RF bracket. Refer to Figure 15-8 on page 400. Torque the screws to 9 inch-pounds. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 451 14.Replace the top brace and reference bracket. Refer to the “Top Brace” replacement procedure. 15.Replace the rear panel. Refer to the “Rear Panel” replacement procedure. 16.Replace the instrument outer case. Refer to the “Instrument Outer Case” replacement procedure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 452: Fan Assembly
15-48. Remove the eight screws (1) that attach the fan assembly to the chassis. Figure 15-48 Fan Assembly Removal 5. Unplug the fan wires from the motherboard. The fan assembly can now be lifted from the chassis. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 453 4. With the rivets center posts raised, snap the rivets into place through the fan grill and fan bracket and into the fan. Screw the center posts into place. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 454: Replacement
3. Replace the Front Frame Assembly. Refer to the “Front Frame Assembly” replacement procedure. 4. Replace the top brace. Refer to the “Top Brace” replacement procedure. 5. Replace the instrument outer case. Refer to the “Instrument Outer Case” replacement procedure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 455: Input Connector Assembly
(2) to the chassis. The connector assembly can now be lifted from the chassis. 5. To remove the gusset (5) remove the three screws (4), one on the side of the chassis and two on the bottom. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 456: Replacement
Torque to 9 inch-pounds. 4. Replace the Front Frame Assembly. Refer to the “Front Frame Assembly” replacement procedure. 5. Replace the instrument outer case. Refer to the “Instrument Outer Case” replacement procedure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 457: Front Frame Assembly
3. Refer to Figure 15-51. Using the T-10 driver, remove the eight screws (1), four on each side, to detach the Front Frame Assembly from the chassis. Figure 15-51 Front Frame Assembly Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 458: Replacement
Torque to 9 inch pounds. 3. If Option EXM, External Mixing, is installed attach semi-rigid LO/IF cable. Torque to 10 inch-pounds. 4. Replace the outer case. Refer to the “Instrument Outer Case” replacement procedure. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 459: Bail Handle Removal (Option Prc)
2. Using the T-20 driver, remove the two screws (3) on each front bumper (4) and remove from the front frame. 3. When replacing these parts, torque to 21 inch-pounds. Figure 15-53 Bail Handle and Front Bumpers Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 460: Front Frame Assembly Components
A1MP14 Shield A1A1 Front Frame A1MP10 Bracket front panel shield A1A2 Front Panel Control Board A1MP11 Display Bracket, Front Panel A1W1 Flex Circuit, Display to Front Panel Control Board A1W2 Cable Assembly, Backlight Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 461 Assembly Replacement Procedures Front Frame Assembly Figure 15-55 Front Frame Exploded View Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 462 A1MP11 Display Bracket, Front Panel A1MP10 Bracket front panel shield A1W1 Flex Circuit, Display to Front Panel Control Board A1W2 Cable Assembly, Backlight A1MP14 Shield W1 Cable, Front Panel Interface Board to Motherboard (Ribbon) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 463 3. When replacing the front panel shield, torque all screws to 9 inch-pounds, When replacing ribbon cable W1 press firmly on each side to ensure the hooks catch on the boards mating connector. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 464 1. Refer to Figure 15-57. To remove the Front Panel Control Shield (1), remove the two screws (2) (0515-1946) and the two screws (3) (0515-0372). Figure 15-57 Front Panel Control Shield and Board Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 465 Figure 15-58. To remove the Front Panel Control board (1), remove the seven screws (2) (0515-0372). When replacing the board torque the screws to 9 inch-pounds. Figure 15-58 Front Panel Control Board Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 466: Display Assembly
(3) (0515-1946). The display assembly (1) can now be lifted out of the front frame. When replacing the display assembly in the front frame, torque the screws to 9 inch-pounds. Figure 15-59 Display Removal Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 467 15-60. To separate the display and display holddown from the display bracket, remove the four screws (1) (0515-0365). When reassembling the display assembly, torque the screws to 2 inch-pounds. Figure 15-60 Display and Bracket Separation Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 468 To remove the keyboard (1), remove the eight screws (2) (0515-0430). When replacing the keyboard into the front frame, torque the screws to 9 inch-pounds. Replace the RPG knob by firmly pushing it onto the shaft. Figure 15-61 Keyboard Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 469 3. Remove the protective film from the new keypad (if replacing). Lay the keypad on the keyboard and pull up on the tabs from the back of the board to seat them in place. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 470 Assembly Replacement Procedures Front Frame Assembly Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 471: Post-Repair Procedures
Keysight NFA Series Noise Figure Analyzers Service Guide Post-Repair Procedures What You Will Find in This Chapter This chapter provides information that will enable you to return an instrument to full operation following the replacement of any instrument assembly. This information includes a table that shows which adjustments and/or performance tests must be executed after replacing an assembly.
Page 472: Post-Repair Procedures
The following procedures are also included in the “Additional Tasks” on page 476. — “Calibration Data Backup and Restore” — “BIOS Settings Verification” — “Operating System Initialization” — “FPGA Synchronization” — “Programming Model and Serial Numbers” Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 473 Frequency Response (All Tests) All Adjustments None Residual Responses Power Supply Displayed Average Noise Level Spurious Responses None Residual Responses Midplane board Displayed Average Noise Level None Residual Responses Motherboard Displayed Average Noise Level Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 474 Front End Control Displayed Average Noise Level System YTF Alignment (Press Assembly Absolute Amplitude Accuracy Alignments Ad vanced Frequency Response (All Tests) Characterize Preselector Front End Controller Attenuator Adjustment (Option CR3 or CRP) Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 475 See Chapter 18, “Instrument Software” for instructions on updating the instrument software to the latest version. Some Adjustment tests may be found in the Utility portion of the Test Plan. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 476: Additional Tasks
2. Connect a USB FLASH drive to one of the front panel USB port. 3. Press System, Alignments, Backup or Restore Align Data. 4. After the XSA application closes the Alignment Data Wizard window as shown in Figure 16-1 will appear. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 477 3. Using the mouse double-click on the Windows Explorer link on the desktop and navigate to the following folder: C:\Program Files\Agilent\SignalAnalysis\Physics 4. Double-click on BackupAndRestore.exe and the window shown in Figure 16-2 will appear. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 478 7. Select “Backup” and wait for the calibration database to be backed up. 8. When the backup has completed close the Calibration Data Backup And Restore window. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 479 Backup or Restore Align Data... The Alignment Data Wizard window as shown in Figure 16-1 will appear. 4. Follow the on-screen instruction to restore the previously saved calibration data from the USB FLASH drive. 5. Cycle instrument power. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 480 1. Connect an external USB keyboard to one of the front panel USB ports. 2. Turn on instrument power. 3. Confirm Keysight Technologies splash screen comes up within a few seconds. 4. Press the key on the keyboard specified on the initial boot screen to enter the setup utility.
Page 481 Initialization 1. With the new disk drive installed power the instrument on. 2. Within a few seconds you will see the initial Keysight Technologies splash screen, and then the boot selection menu as seen in Figure 16-3.
Page 482 If the initialization process would like to be postponed select “Do Not Agree” at this time to safely shut the instrument off. The next time this disk drive is powered on this process will be restarted. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 483 Figure 16-5 Anti-Virus Message 7. The disk drive in use is now ready for further configuration. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 484 3. Using the mouse double-click on the Windows Explorer link on the desktop and navigate to the following folder: C:\Program Files\Agilent\SignalAnalysis\Physics 4. In this folder find and execute the file named: FPGA_Prog.bat Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 485 7. The programming of the FPGA code could take a few minutes to complete. Once it has finished the instrument will reboot itself to use the new code and this process will then be completed. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 486 A7 Midplane board assembly replacement. To program the model and serial numbers into a replacement A7 Midplane board assembly the N7800A Keysight Calibration Application Software will be required. Information regarding N7800A Keysight Calibration Application Software can be found at: http://www.keysight.com/find/calibrationsoftware...
Page 487: 17 Functional Tests
Keysight NFA Series Noise Figure Analyzers Service Guide 17 Functional Tests Functional Test Performance Verification Functional tests are tests of various instrument parameters that give a high degree of confidence that the analyzer is operating correctly. They are recommended as a check of analyzer operation for incoming inspection or after a repair.
Page 488: Before Performing A Functional Test
Press System, Alignments, Align Now, Align Now All. Functional test accuracy depends on the precision of the test equipment used. Ensure that all of the test equipment is calibrated before running a functional test. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 489: Test Equipment
10 dB Step Attenuator Frequency: 50 MHz 8495A 8496A Range: 0 to 70 dB 10 dB Fixed Attenuator Frequency: 50 MHz 8493C Option 010 8493A Option (2 required) VSWR: < 1.2:1 8493B Option Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 490 Frequency: 50 MHz to 3.6 GHz 8481D 8485D 8487D Amplitude: –70 to –10 dBm Pxx other Low Power Sensor Frequency: 50 MHz to 44 GHz c 8487D than P03 Amplitude: –70 to –10 dBm Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 491 PSG model numbers: E8244A, E8254A, E8247C Option 520, E8247C Option H31 or 540, E8257D Option 520, E8257D Option 550, E8257D Option 567, E8267D Option 544. c. Maximum frequency equal to or greater than the maximum frequency of the preamplifier option. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 492: Displayed Average Noise Level (Danl)
Normal view. Press OK. Press Mode Preset on the analyzer. 3. Set up the signal analyzer by pressing: FREQ, Center Frequency, 10, MHz Input/Output, Input, RF Coupling, select DC FREQ, Span, 10, kHz Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 493 Table 17-2 on page 492. Press: FREQ, Center Frequency, [Table 2-1 Value], GHz 13.Repeat step 4 through step 12 to fill in the remainder of Table 17-2 on page 492 for your analyzer frequency range. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 494 2 GHz –145 –149 6 GHz –144 –142 13 GHz –140 –144 20 GHz –133 –142 26.5 GHz –129 –139 30 GHz –135 35 GHz –130 40 GHz –130 43.5 GHz –130 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 495: Frequency Readout Accuracy
Frequency: 10 MHz to 1.51 GHz 11500E 1 meter VSWR: < 1.4:1 Cable, BNC, 120 cm Frequency: 10 MHz 10503A Synthesized Sweeper Frequency: 10 MHz to 1.51 GHz a. For N8973B, 74B, 75B b. For N8976B Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 496: Procedure
17-4. 6. Change the synthesized sweeper frequency to match the center frequency of the analyzer. 7. Repeat step 4 through step 6 until the Marker Frequency Readout column Table 17-4 is complete. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 497 1505.44 MHz 54.1 1505 1504.8122 MHz 1505.1878 MHz 7.95 1505 1504.97240 MHz 1505.0276 MHz 0.106 1505 1504.999630 MHz 1505.000370 MHz 1.98 517.59 517.58316 MHz 517.59684 MHz 1.98 832.50 832.49316 MHz 832.50684 MHz Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 498: Second Harmonic Distortion (Shd)
Filter, 50 MHz Low Pass Cutoff Frequency: 50 MHz 0955-0306 Rejection at 65 MHz: > 40 dB Rejection at 75 MHz: > 60 dB Synthesized Sweeper Frequency: 50 MHz Spectral Purity: Better than –30 dBc Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 499: Procedure
7. On the analyzer, activate the marker delta function by pressing the Marker and Delta keys. 8. On the signal analyzer, press: FREQ, Center Frequency, 80, MHz Meas Setup, Avg/Hold Number, 20, Enter Trace, Trace Average Single Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 500 9. Press Peak Search. Enter the displayed value under the Measured Second Harmonic Distortion (dBc) heading in Table 17-5. Table 17-5 Second Harmonic Distortion Results Applied Frequency Measured Second Harmonic Distortion Mixer Level Specification (MHz) (dBc) (dBm) (dBc) –10 –55 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 501: Amplitude Accuracy At 50 Mhz
Amplitude Range: −25 dBm to 10 dBm 8485A Power Splitter 3.5 mm (f) connectors 11667B 6 dB loss Synthesized Sweeper Typical Temperature Stability: 0.01 dBc/°C a. For N8973B, 74B, 75B b. For N8976B Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 502: Procedure
CW, 50, MHz Power Level, -4, dBm RF (On) 6. Set up the signal analyzer by pressing: Input/Output, Freq Ref Input, Freq Ref Input External FREQ, Center Frequency, 50, MHz Span, 2, MHz Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 503 Amplitude Test Limit Source (dB) (MHz) Amplitude Amplitude Accuracy (dB) Amplitude Meas_amp Power_meter Error (dBm) (dBm) (dBm) (dB) ±1.2 dB ±1.2 dB ±1.2 dB ±1.2 dB ±1.2 dB ±1.2 dB ±1.2 dB Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 504: Testing Preamp Option (P03, P07, P26, P44)
Amplitude Accuracy Results (Option P03, P07, P26, P44) Nominal Res BW Span Measured Power Meter Amplitude Test Limit Source Low- band (kHz) (kHz) Amplitude Amplitude Accuracy (dB) Amplitude Preamp Meas_amp Power_meter Error (dBm) (dBm) (dBm) (dB) ±1.30 dB Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 505: Frequency Response (Flatness)
Cables, BNC 120 cm Frequency: 10 MHz 10503A Power Meter Compatible with power sensor E4418B Power Sensor Frequency Range: 50 MHz to 26.5 GHz 8485A Frequency Range: 50 MHz to 44 GHz 8487A Power Sensor Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 506: Procedure
Connect the power splitter to the signal analyzer input using the appropriate adapter. Do not use a cable. 3. Assure the signal analyzer’s built-in auto alignment has been performed within the last 24 hours. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 507 (Meas - Meas @ 50 MHz) Error Error 18.Enter the computed flatness error valu651e into the Flat column of Norm Table 17-8. 19.Compare the value of Flat to the test limit. Norm Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 508 26 GHz ±4.2 dB 29 GHz ±3.5 dB 32 GHz ±3.5 dB 35 GHz ±4.2 dB 38 GHz ±4.2 dB 41 GHz ±4.2 dB 42.5 GHz ±4.2 dB 43.5 GHz ±4.2 dB Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 509: Frequency Response (Flatness), Preamp On
Cable, 2.4 mm, 1 meter VSWR: < 1.55:1 Cables, BNC 120 cm Frequency: 10 MHz 10503A Power Meter Compatible with power sensor E4418B Attenuator, 30 dB Fixed Frequency: 50 MHz 11708A Accuracy: ±0.05 dB Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 510: Procedure
For Options P03, P07, and P26 b. For Option P44 Figure 17-6 Frequency Response Test Setup Procedure 1. Zero and calibrate the power meter and power sensor as described in the power meter operation manual. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 511 15.Repeat step 7 through step 14 and complete the remainder of Table 17-8 for the frequency range of your preamp. 16.Compute the measurement error (Meas = Meas - Power Error Meter Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 512 (Meas - Meas @ 50 MHz) Error Error 18.Enter the computed flatness error value into the Flat column of Table Norm 17-8. 19.Compare the value of Flat to the test limit. Norm Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 513 26 GHz ±4.0 dB 29 GHz ±4.0 dB 32 GHz ±4.0 dB 35 GHz ±5.0 dB 38 GHz ±5.0 dB 41 GHz ±5.0 dB 42.5 GHz ±5.0 dB 43.5 GHz ±5.0 dB Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 514: Scale Fidelity
VSWR: < 1.4:1 Cable, BNC 120 cm Frequency: 10 MHz 10503A Synthesized Sweeper Output Level Accuracy: 0 to –15 dBm: ±1.0 dB at 50 MHz a. For N8973B, 74B, 75B b. For N8976B Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 515: Procedure
Peak Search 5. Set the external 10 dB step attenuator to 0 dB. 6. Adjust the amplitude on the signal source until the marker amplitude on the analyzer reads –15 dBm ±0.2 dB. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 516 Check delta marker reading against the test limits. Table 17-10 Scale Fidelity Results Minimum Marker Del ta Value Maximum External Attenuator Setting (dB) (dB) (dB) Reference –11.0 –9.0 –21.0 –19.0 –31.0 –29.0 –41.0 –39.0 –51.0 –49.0 Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 517: What You Will Find In This Chapter
Keysight NFA Series Noise Figure Analyzers Service Guide 18 Instrument Software What You Will Find in This Chapter Instrument Software Overview on page 518 Software Licensing on page 519 Software Updates on page 520 Instrument Measurement Application Software on page 520...
Page 518: Instrument Software Overview
89601B VSA software is installed in each instrument as it left the factory, it must be updated, and kept in sync with the rest of the instrument application software independently. Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 519: Software Licensing
Instrument Software Software Licensing Software Licensing All application software needs to have a valid license in order to be available for use. This also includes the spectrum analyzer application (N9060C). Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 520: Software Updates
The latest revision of the software, along with complete installation instructions, can be obtained as follows: Web Download: The latest revision of the software can be downloaded from: http://www.keysight.com/find/N8973B_software http://www.keysight.com/find/N8974B_software http://www.keysight.com/find/N8975B_software http://www.keysight.com/find/N8976B_software Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 521 Band Lock menu description, part number, removal, basics, troubleshooting, troubleshooting, troubleshooting, battery A7 midplane assembly A16 reference assembly see A4BT1 CPU board battery part number, description, before troubleshooting, A8 motherboard Keysight NFA Noise Figure Analyzers Service Guide...
Page 522 382, 383, 384, 385, high band signal level verification, Measurement Guides and external VGA monitor, high band troubleshooting, 169, 173, Programming Examples Guides on 216, CD-ROM, memory card see A4A1 memory card Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 523 A5 SSD assembly see A12 YTF SSD module probes see A12 YTF see A5 SSD module AC and DC, standby LED, static safety accessories, static-safe workstation, status messages, storage device USB, Keysight NFA Series Noise Figure Analyzers Service Guide...
Page 524 This information is subject to change without notice. © Keysight Technologies 2017 Edition 1, August 2017 N8973-90008 www.keysight.com...

This manual is also suitable for:

N8974b N8975b N8976b

Keysight N8973B Service Manual

1 Overview

2 Boot up and Initialization Troubleshooting

3 Instrument Messages

4 RF Section Troubleshooting (N8973B, 74B, 75B Analyzers)

5 RF Section Troubleshooting (N8976B)

6 Front End Control Troubleshooting

7 Analog/Digital if Troubleshooting

8 L.O. Synthesizer/Reference Troubleshooting

9 Cpu/Disk Drive Troubleshooting

10 Power Supply/Midplane Troubleshooting

11 Front Panel/Motherboard Troubleshooting

12 Block Diagrams

13 Service and Diagnostics Menus

14 Replaceable Parts

15 Assembly Replacement Procedures

16 Post-Repair Procedures

17 Functional Tests

Quick Links

Noise Figure Analyzers

Troubleshooting

Related Manuals for Keysight N8973B

Summary of Contents for Keysight N8973B