Service Manual
WCA230A & WCA280A
Portable Wireless Communication Analyzers
071-1257-01
This document applies to firmware version 2.4
and above.
Warning
The servicing instructions are for use by qualified
personnel only. To avoid personal injury, do not
perform any servicing unless you are qualified to
do so. Refer to all safety summaries prior to
performing service.
www.tektronix.com
Copyright © Tektronix, Inc. All rights reserved. Licensed software products are owned by Tektronix or its suppliers and
are protected by United States copyright laws and international treaty provisions.
Use, duplication, or disclosure by the Government is subject to restrictions as set forth in subparagraph (c)(1)(ii) of the
Rights in Technical Data and Computer Software clause at DFARS 252.227-7013, or subparagraphs (c)(1) and (2) of the
Commercial Computer Software – Restricted Rights clause at FAR 52.227-19, as applicable.
Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes
that in all previously published material. Specifications and price change privileges reserved.
TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.
Contacting Tektronix
Tektronix, Inc.
14200 SW Karl Braun Drive or P.O. Box 500
Beaverton, OR 97077 USA
For product information, sales, service, and technical support:
H In North America, call 1-800-833-9200.
H Worldwide, visit www.tektronix.com to find contacts in your area.
Warranty 2
Tektronix warrants that this product will be free from defects in materials and workmanship for a period of one (1) year
from the date of shipment. If any such product proves defective during this warranty period, Tektronix, at its option, either
will repair the defective product without charge for parts and labor, or will provide a replacement in exchange for the
defective product. Parts, modules and replacement products used by Tektronix for warranty work may be new or
reconditioned to like new performance. All replaced parts, modules and products become the property of Tektronix.
In order to obtain service under this warranty, Customer must notify Tektronix of the defect before the expiration of the
warranty period and make suitable arrangements for the performance of service. Customer shall be responsible for
packaging and shipping the defective product to the service center designated by Tektronix, with shipping charges prepaid.
Tektronix shall pay for the return of the product to Customer if the shipment is to a location within the country in which the
Tektronix service center is located. Customer shall be responsible for paying all shipping charges, duties, taxes, and any
other charges for products returned to any other locations.
This warranty shall not apply to any defect, failure or damage caused by improper use or improper or inadequate
maintenance and care. Tektronix shall not be obligated to furnish service under this warranty a) to repair damage resulting
from attempts by personnel other than Tektronix representatives to install, repair or service the product; b) to repair
damage resulting from improper use or connection to incompatible equipment; c) to repair any damage or malfunction
caused by the use of non-Tektronix supplies; or d) to service a product that has been modified or integrated with other
products when the effect of such modification or integration increases the time or difficulty of servicing the product.
THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THE PRODUCT IN LIEU OF ANY OTHER
WARRANTIES, EXPRESS OR IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. TEKTRONIX’
RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND EXCLUSIVE REMEDY
PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY. TEKTRONIX AND ITS VENDORS WILL
NOT BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS ADVANCE NOTICE OF THE POSSIBILITY
OF SUCH DAMAGES.
Table of Contents
Specifications
General Safety Summary xi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Safety Summary xiii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preface xv. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual Structure xv. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual Conventions xvi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Finding Other Information xvi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introduction xvii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Performance Check Interval xvii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Strategy for Servicing xvii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Product Overview 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Features 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Application 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Difference between WCA230A and WCA280A 1–2. . . . . . . . . . . . . . . . . . . . . . . . .
Real-Time Analysis 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Architecture 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 1–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Performance Conditions 1–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical Characteristics 1–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Physical Characteristics 1–23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Environmental Characteristics 1–23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Information
Installation 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Supplying Operating Power 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Environment 2–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Applying Power 2–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Powering Off the Analyzer 2–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Restart 2–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting Up the Stand 2–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Repackaging Instructions 2–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installed Options 2–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Instructions 2–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preparations 2–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Displaying Spectrum 2–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using Markers and Peak Search 2–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using Averaging and Comparison Displays 2–31. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Displaying a Spectrogram 2–34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spectrum Analysis 2–37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Modulation Analysis 2–41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using Windows XP 2–48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Turning Off the Power 2–50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WCA230A & WCA280A Service Manual
i
Table of Contents
Theory of Operation
RF Input Circuit 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RF3 Module 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RF2 Module 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RF5 Module 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RF4 Module 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A10 A/D Board 3–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A20 DDC Board 3–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A30 Trigger Board (Optional) 3–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A40 Memory Board 3–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Supply Circuit 3–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standby Power and On/Standby Switch 3–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A50 Mother Board 3–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A60 Front Key Board 3–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A62 Front Connection Board 3–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Performance Verification
Conventions 4–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brief Procedures 4–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional Check 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnostics 4–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Performance Tests 4–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prerequisites 4–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment Required 4–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto Tests 4–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual Tests 4–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Test Record 4–48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adjustment Procedures
ii
Requirements for Performance 5–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment Required 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preparation 5–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Self Calibration 5–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto Calibration 5–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reference Oscillator Frequency Adjustment 5–18. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reconfiguration of RF Modules 5–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WCA230A & WCA280A Service Manual
Maintenance
Table of Contents
Related Maintenance Procedures 6–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preparation 6–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Cleaning 6–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal and Installation Procedures 6–7. . . . . . . . . . . . . . . . . . . . . . . . . .
Preparation 6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Access Procedure 6–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Procedures for External Modules 6–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Procedures for RF Modules 6–27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Procedures for CPU Board and Disk Modules 6–31. . . . . . . . . . . . . . . . . . . . . . . . . .
Procedures for Mother Board and its Daughter Boards 6–36. . . . . . . . . . . . . . . . . . . .
Procedures for Power Supply Modules on the Instrument Bottom 6–43. . . . . . . . . . .
Procedures for RF1 Modules on the Instrument Bottom 6–48. . . . . . . . . . . . . . . . . . .
Procedures for Front Panel Modules 6–55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Procedures for Chassis Modules 6–61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting 6–67. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting Procedure 6–67. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Symptoms and Faulty Modules 6–80. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Notes for Changing Modules or Parts 6–82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Options
Electrical Parts List
Diagrams
Mechanical Parts List
Options and Accessories 7–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Options 7–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standard Accessories 7–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Accessories 7–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replaceable Parts 10–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Ordering Information 10–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using the Replaceable Parts List 10–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WCA230A & WCA280A Service Manual
iii
Table of Contents
List of Figures
Figure 1–1: Concept of the swept spectrum analyzer 1–3. . . . . . . . . . . . .
Figure 1–2: Sweep of resolution filter 1–3. . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 1–3: Concept of the real-time spectrum analyzer 1–4. . . . . . . . . .
Figure 1–4: Concurrent acquisition 1–4. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 1–5: Frame acquisition 1–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 1–6: Block diagram 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–1: AC Input (rear panel) 2–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–2: Principal power switch (rear panel) 2–5. . . . . . . . . . . . . . . . .
Figure 2–3: Front panel power switch (ON/STANDBY switch) 2–5. . . . .
Figure 2–4: Initial screen 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–5: RF INPUT connector 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–6: Setting up the stand 2–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–7: Cable connection 2–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–8: Principal power switch (rear panel) 2–13. . . . . . . . . . . . . . . . .
Figure 2–9: Power switch (ON/STANDBY) 2–13. . . . . . . . . . . . . . . . . . . . .
Figure 2–10: Initial screen 2–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–11: Frequency, span, and amplitude settings 2–16. . . . . . . . . . . .
Figure 2–12: Menu items for numeric value input 2–17. . . . . . . . . . . . . . . .
Figure 2–13: Numeric value entry keypad 2–18. . . . . . . . . . . . . . . . . . . . . .
Figure 2–14: Center frequency of 800 MHz, span of 15 MHz 2–18. . . . . .
Figure 2–15: Center frequency of 800 MHz, span of 100 kHz 2–20. . . . . .
Figure 2–16: Setting amplitude 2–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–17: Menu items for numeric value input 2–22. . . . . . . . . . . . . . . .
Figure 2–18: Reference level of 10 dBm 2–22. . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–19: Status indicator 2–23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–20: Measurement with a single marker 2–26. . . . . . . . . . . . . . . . .
Figure 2–21: Measurement with the delta marker 2–28. . . . . . . . . . . . . . . .
Figure 2–22: Searching for the peak 2–30. . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–23: Comparing a new waveform with an averaged
waveform 2–32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–24: Comparison display with averaged waveform 2–33. . . . . . . .
Figure 2–25: Concurrent display of spectrum and spectrogram 2–34. . . .
Figure 2–26: Tall display of spectrum and spectrogram 2–35. . . . . . . . . . .
Figure 2–27: Spectrogram view 2–36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
iv
WCA230A & WCA280A Service Manual
Table of Contents
Figure 2–28: Channel power measurement 2–38. . . . . . . . . . . . . . . . . . . . .
Figure 2–29: Channel power measurement (Channel Bandwidth
= 40 kHz) 2–39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–30: Carrier frequency measurement 2–40. . . . . . . . . . . . . . . . . . .
Figure 2–31: MODE keys 2–41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–32: IQ level measurement 2–42. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–33: Analysis range settings 2–44. . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–34: Frame and block 2–44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–35: Changing the acquisition length 2–45. . . . . . . . . . . . . . . . . . .
Figure 2–36: Single view display 2–46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–37: Scale settings 2–47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–38: USB ports (side panel) 2–48. . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 4–1: Spectrum of the calibration signal (50 MHz, –20 dBm) 4–5.
Figure 4–2: Setup display 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 4–3: Reference level setting and A/D overflow indicator 4–7. . . .
Figure 4–4: Spectrogram display 4–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 4–5: Diagnostic screen 4–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 4–6: Initial test hookup 4–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 4–7: Initial test hookup 4–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 4–8: Initial hookup for setting up the power meter and
sensor 4–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 4–9: Hookup for calibrating the power sensor 4–23. . . . . . . . . . . . .
Figure 4–10: Hookup for setting the signal generator output 4–23. . . . . . .
Figure 4–11: Hookup for checking the absolute amplitude
accuracy 4–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 4–12: Initial test hookup 4–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 4–13: Initial test hookup 4–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 4–14: Initial test hookup 4–35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 4–15: Initial test hookup 4–38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 4–16: Initial test hookup 4–41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 4–17: Initial test hookup 4–44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 5–1: Hookup for storing the cal factors in the power meter 5–5. .
Figure 5–2: Initial test hookup 5–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 5–3: Hookup for calibrating the power sensor 5–8. . . . . . . . . . . . .
Figure 5–4: UNCAL display 5–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 5–5: Calibration menu 5–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 5–6: Center offset 5–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 5–7: DC offset 5–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WCA230A & WCA280A Service Manual
v
Table of Contents
Figure 5–8: Initial test hookup 5–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 5–9: Initial test hookup 5–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 5–10: R232 location (top view of the card cage) 5–19. . . . . . . . . . . .
Figure 5–11: Test hookup 5–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 5–12: Test hookup 5–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–1: Analyzer orientation 6–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–2: External modules 6–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–3: RF modules 6–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–4: CPU board and disk modules 6–14. . . . . . . . . . . . . . . . . . . . . .
Figure 6–5: Mother board and its daughter boards 6–15. . . . . . . . . . . . . .
Figure 6–6: Bottom modules – Power supply 6–16. . . . . . . . . . . . . . . . . . . .
Figure 6–7: Bottom modules – RF1 (WCA230A) 6–17. . . . . . . . . . . . . . . . .
Figure 6–8: Bottom modules – RF1 (WCA280A) 6–18. . . . . . . . . . . . . . . . .
Figure 6–9: Front panel modules 6–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–10: Chassis modules 6–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–11: Guide to removal procedures 6–21. . . . . . . . . . . . . . . . . . . . . .
Figure 6–12: Line cord and cabinet removal 6–23. . . . . . . . . . . . . . . . . . . .
Figure 6–13: Front cushion removal 6–24. . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–14: Cabinet modules removal 6–26. . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–15: RF modules removal 6–28. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–16: CPU board removal 6–32. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–17: Disk module removal 6–34. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–18: A10 A/D board removal 6–37. . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–19: Daughter boards removal 6–40. . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–20: Mother board removal 6–42. . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–21: Power supply 1 and 2 removal 6–44. . . . . . . . . . . . . . . . . . . . .
Figure 6–22: Power supply modules removal 6–46. . . . . . . . . . . . . . . . . . . .
Figure 6–23: RF1 modules removal – 1 6–49. . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–24: RF1 modules removal – 2 (WCA230A) 6–51. . . . . . . . . . . . . .
Figure 6–25: RF1 modules removal – 2 (WCA280A) 6–53. . . . . . . . . . . . . .
Figure 6–26: Front panel assembly removal 6–56. . . . . . . . . . . . . . . . . . . . .
Figure 6–27: Front panel modules removal 6–57. . . . . . . . . . . . . . . . . . . . .
Figure 6–28: LCD display removal 6–60. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–29: Fan and side panel removal 6–62. . . . . . . . . . . . . . . . . . . . . . .
Figure 6–30: Board guide bracket removal 6–63. . . . . . . . . . . . . . . . . . . . .
Figure 6–31: Rear panel modules 6–65. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–32: Troubleshooting procedure 1 — Power supply system 6–68.
vi
WCA230A & WCA280A Service Manual
Table of Contents
Figure 6–33: Troubleshooting procedure 2 — Display and CPU
system 6–69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–34: Troubleshooting procedure 3 — Signal path 6–70. . . . . . . . .
Figure 6–35: Top view for cable interconnection 6–75. . . . . . . . . . . . . . . . .
Figure 6–36: Bottom view for cable interconnection (WCA230A) 6–76. . .
Figure 6–37: Bottom view for cable interconnection (WCA280A) 6–77. . .
Figure 6–38: A70 DC power supply board 6–79. . . . . . . . . . . . . . . . . . . . . .
Figure 9–1: Block diagram 9–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 9–2: Interconnect diagram (WCA230A) 9–5. . . . . . . . . . . . . . . . . .
Figure 9–3: Interconnect diagram (WCA280A) 9–7. . . . . . . . . . . . . . . . . .
Figure 10–1: External modules 10–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 10–2: Front-panel assembly – 1 10–7. . . . . . . . . . . . . . . . . . . . . . . . .
Figure 10–3: Front-panel assembly – 2 10–9. . . . . . . . . . . . . . . . . . . . . . . . .
Figure 10–4: RF modules 10–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 10–5: Mother board and its daughter boards – 1 10–13. . . . . . . . . .
Figure 10–6: Mother board and its daughter boards – 2 10–15. . . . . . . . . .
Figure 10–7: Disk modules 10–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 10–8: Bottom modules – Power supply 10–19. . . . . . . . . . . . . . . . . . .
Figure 10–9: Bottom modules – RF1 (WCA230A) 10–21. . . . . . . . . . . . . . . .
Figure 10–10: Bottom modules – RF1 (WCA280A) 10–23. . . . . . . . . . . . . . .
Figure 10–11: Bottom modules – Interconnection 10–25. . . . . . . . . . . . . . . .
Figure 10–12: Chassis modules – 1 10–27. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 10–13: Chassis modules – 2 10–29. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 10–14: Rackmount – 1 10–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 10–15: Rackmount – 2 10–33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WCA230A & WCA280A Service Manual
vii
Table of Contents
List of Tables
Table 1–1: Frequency 1–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–2: Spectrum purity 1–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–3: Noise sideband 1–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–4: Input 1–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–5: Amplitude 1–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–6: Dynamic range 1–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–7: Spurious response 1–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–8: Acquisition 1–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–9: Sampling rate 1–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–10: Frame time 1–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–11: Digital demodulation 1–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–12: Analog demodulation 1–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–13: RBW (Resolution Bandwidth) 1–19. . . . . . . . . . . . . . . . . . . . .
Table 1–14: Trigger 1–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–15: Measurement function 1–20. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–16: Display 1–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–17: Marker, trace, and display line 1–21. . . . . . . . . . . . . . . . . . . . .
Table 1–18: Controller and interface 1–21. . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–19: Power requirements 1–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–20: Power connector 1–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–21: Physical characteristics 1–23. . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 1–22: Environmental characteristics 1–23. . . . . . . . . . . . . . . . . . . . .
Table 1–23: Certifications and compliances 1–24. . . . . . . . . . . . . . . . . . . . .
viii
Table 2–1: Power-cord conductor identification 2–1. . . . . . . . . . . . . . . . .
Table 2–2: Power cord identification 2–2. . . . . . . . . . . . . . . . . . . . . . . . . .
Table 4–1: Span and RBW 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 4–2: Internal diagnostic program 4–8. . . . . . . . . . . . . . . . . . . . . . . .
Table 4–3: Test equipment 4–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 4–4: Spurious measurement 4–40. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 5–1: Test equipment 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 6–1: Relative susceptibility to static-discharge damage 6–3. . . . . .
Table 6–2: External inspection check list 6–5. . . . . . . . . . . . . . . . . . . . . . .
WCA230A & WCA280A Service Manual
Table of Contents
Table 6–3: Internal inspection check list 6–6. . . . . . . . . . . . . . . . . . . . . . .
Table 6–4: Summary of procedures 6–9. . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 6–5: Tools required for module removal 6–10. . . . . . . . . . . . . . . . . .
Table 6–6: Normal supply voltages 6–78. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 6–7: Test point voltages on A70 6–79. . . . . . . . . . . . . . . . . . . . . . . . . .
Table 6–8: Symptoms and faulty modules 6–80. . . . . . . . . . . . . . . . . . . . . .
Table 7–1: Power cord identification 7–2. . . . . . . . . . . . . . . . . . . . . . . . . .
Table 7–2: Standard accessories 7–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 7–3: Accessories for optional software 7–3. . . . . . . . . . . . . . . . . . . .
Table 7–4: Optional accessories 7–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WCA230A & WCA280A Service Manual
ix
Table of Contents
x
WCA230A & WCA280A Service Manual
General Safety Summary
Review the following safety precautions to avoid injury and prevent damage to
this product or any products connected to it. To avoid potential hazards, use this
product only as specified.
Only qualified personnel should perform service procedures.
To Avoid Fire or
Personal Injury
Use Proper Power Cord. Use only the power cord specified for this product and
certified for the country of use.
Ground the Product. This product is grounded through the grounding conductor
of the power cord. To avoid electric shock, the grounding conductor must be
connected to earth ground. Before making connections to the input or output
terminals of the product, ensure that the product is properly grounded.
Observe All Terminal Ratings. To avoid fire or shock hazard, observe all ratings
and markings on the product. Consult the product manual for further ratings
information before making connections to the product.
Do Not Operate Without Covers. Do not operate this product with covers or panels
removed.
Avoid Exposed Circuitry. Do not touch exposed connections and components
when power is present.
Do Not Operate With Suspected Failures. If you suspect there is damage to this
product, have it inspected by qualified service personnel.
Do Not Operate in Wet/Damp Conditions.
Do Not Operate in an Explosive Atmosphere.
Provide Proper Ventilation. Refer to the manual’s installation instructions for
details on installing the product so it has proper ventilation.
Symbols and Terms
WCA230A & WCA280A Service Manual
Terms in this Manual. These terms may appear in this manual:
WARNING. Warning statements identify conditions or practices that could result
in injury or loss of life.
CAUTION. Caution statements identify conditions or practices that could result in
damage to this product or other property.
xi
General Safety Summary
Terms on the Product. These terms may appear on the product:
DANGER indicates an injury hazard immediately accessible as you read the
marking.
WARNING indicates an injury hazard not immediately accessible as you read the
marking.
CAUTION indicates a hazard to property including the product.
Symbols on the Product. The following symbols may appear on the product:
WARNING
High Voltage
Protective Ground
(Earth) Terminal
CAUTION
Refer to Manual
xii
WCA230A & WCA280A Service Manual
Service Safety Summary
Only qualified personnel should perform service procedures. Read this Service
Safety Summary and the General Safety Summary before performing any service
procedures.
Do Not Service Alone. Do not perform internal service or adjustments of this
product unless another person capable of rendering first aid and resuscitation is
present.
Disconnect Power. To avoid electric shock, switch off the instrument power, and
then disconnect the power cord from the mains power.
Use Care When Servicing With Power On. Dangerous voltages or currents may
exist in this product. Disconnect power, remove battery (if applicable), and
disconnect test leads before removing protective panels, soldering, or replacing
components.
To avoid electric shock, do not touch exposed connections.
WCA230A & WCA280A Service Manual
xiii
Service Safety Summary
xiv
WCA230A & WCA280A Service Manual
Preface
Manual Structure
This is the service manual for the WCA230A and WCA280A Portable Wireless
Communication Analyzers. The manual contains information needed to service
the analyzer to the module level.
This manual is divided into sections, such as Specifications and Theory of
Operation. Further, some sections are divided into subsections, such as
Product Description and Removal and Installation Procedures.
Sections containing procedures also contain introductions to those procedures.
Be sure to read these introductions because they provide information needed to
do the service correctly and efficiently. The manual section name and a brief
description of each is given below.
H Specifications contains a description of the analyzer and the applicable
characteristics.
H Operating Information includes general information and operating instruc-
tions.
H Theory of Operation contains circuit descriptions that support service to the
module level.
H Performance Verification contains procedures for confirming that the
analyzer functions properly and meets warranted limits.
H Adjustment Procedures contains procedures for adjusting the analyzer to
meet warranted limits.
H Maintenance contains information and procedures for performing preventive
and corrective maintenance of the analyzer. These instructions include
cleaning, module removal and installation, and fault isolation to the module.
H Options contains information on servicing factory-installed options.
H Electrical Parts List contains a statement referring you to Mechanical Parts
List, where both electrical and mechanical modules are listed.
H Diagrams contains a block diagram and an interconnection diagram.
H Mechanical Parts List includes a table of all replaceable modules, their
descriptions, and their Tektronix part numbers.
WCA230A & WCA280A Service Manual
xv
Preface
Manual Conventions
This manual uses certain conventions that you should become familiar with.
Some sections of the manual contain procedures for you to perform. To keep
those instructions clear and consistent, this manual uses the following conventions:
H Names of front panel controls and menus appear in the same case (initial
capitals, all uppercase, etc.) in the manual as is used on the analyzer front
panel and menus. Front panel names are all upper-case letters; for example,
SPAN, TRIG, and SELECT.
H Instruction steps are numbered unless there is only one step.
Modules
Safety
Throughout this manual, any replaceable component, assembly, or part of the
analyzer is referred to generically as a module. In general, a module is an
assembly (like a circuit board), rather than a component (like a resistor or an
integrated circuit). Sometimes a single component is a module; for example, the
chassis of the analyzer is a module.
Symbols and terms related to safety appear in the Safety Summary near the
beginning of this manual.
Finding Other Information
Other documentation for the WCA230A and WCA280A analyzers includes:
H The WCA230A and WCA280A User Manual contains a tutorial to quickly
H The WCA230A and WCA280A Programmer Manual explains how to use the
describe how to operate the analyzer. It also includes an in-depth discussion
on how to more completely use the analyzer features.
GPIB interface to remotely control the analyzer.
xvi
WCA230A & WCA280A Service Manual
Introduction
This manual contains information needed to properly service the WCA230A and
WCA280A Portable Wireless Communication Analyzers as well as general
information critical to safe and effective servicing.
To prevent personal injury or damage to the analyzer, consider the following
before attempting service:
H The procedures in this manual should be performed only by a qualified
service person.
H Read the General Safety Summary and the Service Safety Summary,
beginning on page xi.
H Read Preparation for Use in section 2, Operating Information.
When using this manual for servicing, be sure to follow all warnings, cautions,
and notes.
Performance Check Interval
Strategy for Servicing
Generally, the performance check described in section 4, Performance Verification, should be done every 12 months. In addition, performance check is
recommended after module replacement.
If the analyzer does not meet performance criteria, repair is necessary.
Throughout this manual, the term “module” refers to any field-replaceable
component, assembly, or part of the analyzer.
This manual contains all the information needed for periodic maintenance of the
analyzer. (Examples of such information are procedures for checking performance.)
Further, it contains all information for corrective maintenance down to the
module level. To isolate a failure to a module, use the fault isolation procedures
found in Troubleshooting, part of section 6, Maintenance. To remove and replace
any failed module, follow the instructions in Removal and Installation Proce-
dures, also part of section 6. After isolating a faulty module, replace it with a
fully-tested module obtained from the factory. Section 10, Mechanical Parts
List, contains part number and ordering information for all replaceable modules.
WCA230A & WCA280A Service Manual
xvii
Introduction
xviii
WCA230A & WCA280A Service Manual
Specifications
Product Overview
The WCA230A and the WCA280A are portable wireless communication
analyzers capable of real-time spectrum analysis and modulated-signal analysis.
The analyzers enable transmitter characteristic evaluation required for mobile
communication systems. Large capacity memory that collects W-CDMA data
up to 2.5 seconds is standard, ensuring even accurate collection and analysis of
super frame signals defined in the 3GPP standard.
Features
H DC to 3 GHz (WCA230A) / 8 GHz (WCA280A) measurement
H 100 Hz to 3 GHz measurement span and 15 MHz vector span
H Real-time analysis for seamless capture of time-varying RF signals
H Spectrum analysis of power, ACPR, C/N, OBW, EBW, and spurious
H Analog modulation analysis of AM, PM, FM, ASK and FSK signals
frequency range
H Digital modulation analysis ranging from BPSK to 256QAM
H Time characteristic analysis including pulse measurements
H CCDF analysis
H AM/AM and AM/PM distortion analyses
H Time-correlated simultaneous views
H Spectrum display
H Spectrogram display (frequency versus time versus power)
H Time domain display (IS-95 standard)
H Analog demodulation display:
time versus modulation factor, phase, or frequency
H Digital demodulation display:
constellation, eye diagram, symbol table, or EVM
H 8.4 inch TFT color display and sturdy cabinet
WCA230A & WCA280A Service Manual
1-1
Product Overview
Application
The WCA230A and the WCA280A can perform real-time analysis for the
following purposes:
H Signal quality analysis of analog and digital modulation
H Understanding frequency and spectral occupancy behavior over time
H Capture and characterization of undesired, unknown, or interfering signals
H Device/system design or operational diagnostic measurement
H Getting answers to elusive EMI problems
H VCO/synthesizer design
H RFID device characterization
H General purpose digital modulation vector signal analysis
H Spectrum monitoring
H Radar measurements
H Characterization, troubleshooting, and verification of wireless designs
(Option):
H GSM/EDGE
H W-CDMA
H HSDPA
H cdma2000 1x
H cdma2000 1xEV–DO
H TD-SCDMA
Difference between WCA230A and WCA280A
The WCA230A and the WCA280A have the same functions except for their
measurement frequency ranges:
WCA230A DC to 3 GHz. . . . . . . . .
WCA280A DC to 8 GHz. . . . . . . . .
1-2
Descriptions in this manual apply to both the WCA230A and the WCA280A
unless otherwise noted.
WCA230A & WCA280A Service Manual
RealĆTime Analysis
Product Overview
This section explains real-time analysis with the comparison of conventional
swept spectrum analyzer and real-time spectrum analyzer.
Conventional Swept
Spectrum Analyzer
Figure 1–1 is a block diagram of the conventional swept spectrum analyzer.
There are two RF input signals in this example. The RF signal is converted to IF
(intermediate frequency) by the swept local oscillator. IF output goes through a
bandpass filter, where resolution of the spectrum analyzer is defined.
RF input
F
Mixer
Resolution
Local
oscillator
filter
Detector
Display
F
Figure 1-1: Concept of the swept spectrum analyzer
The filter is swept from F
start
to F
. See Figure 1–2. Only signals within the
stop
filter bandwidth are observed at one point in time. Signal A is detected first and
then signal B is detected and displayed.
NOTE. An intermittent signal, such as a burst phenomenon, will not be detected
unless it is present at the exact moment that the filter is being swept past it.
F
start
Figure 1-2: Sweep of resolution filter
WCA230A & WCA280A Service Manual
Sweep
AB
F
stop
1-3
Product Overview
RealĆTime Spectrum
Analyzer
The real-time spectrum analyzer is conceptually equipped with a series of
bandpass filters as shown in Figure 1–3. Signals passing through those filters are
concurrently observed and recorded continuously. Signals A and B are concurrently acquired and displayed as shown in Figure 1–4.
Resolution
filter 1
FF
RF input
Resolution
filter 2
Resolution
filter 3
Resolution
filter N
Detector 1
Detector 2
Display
Detector 3
Detector N
Figure 1-3: Concept of the realĆtime spectrum analyzer
Concurrent acquisition
AB
F
start
Figure 1-4: Concurrent acquisition
F
stop
1-4
WCA230A & WCA280A Service Manual
Product Overview
The method used to concurrently acquire signals in a certain frequency range is
not bandpass filters, but FFT (Fast Fourier Transformation). The WCA230A or
WCA280A first acquires a series of frames of data in the time domain, as shown
in Figure 1–5, and then performs the FFT process for each frame. This method
enables continuous analysis of spectra and ensures the capture of real-time
phenomenon such as burst signals in digital mobile communication. The
WCA230A and the WCA280A are equipped with a 51.2 MHz A/D converter to
analyze the spectrum by single scanning for spans up to 15 MHz.
Time
Frame
F F F
F F
Figure 1-5: Frame acquisition
WCA230A & WCA280A Service Manual
1-5
Product Overview
Architecture
Figure 1–6 shows the block diagram of the signal processing system.
RF input
Option
3 GHz / 8 GHz
down converter
External trigger input Trigger detection
Q input
I Input
IF sampling
A/D converter
(optional)
IF sampling
A/D converter
Memory controller
Digital
down converter
FFT
Extended trigger
(optional)
Data memory
64 MB (standard)
256 MB (optional)
Local bus
1-6
Display
Mass Storage
Devices
Figure 1-6: Block diagram
HDD
FDD
PCI bridge
Windows
board PC
USB
LAN
GPIB
VGA
Front panel key
External interface
WCA230A & WCA280A Service Manual
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