Tektronix 1502C User Manual

User Manual

1502C Metallic Time-Domain Reflectometer

070-7169-05

This document applies for firmware version 5.04 and above.

www.tektronix.com

that in all previously published material. Specifications and price change privileges reserved. T ektronix, Inc., P.O. Box 500, Beaverton, OR 97077 TEKTRONIX and TEK are registered trademarks of T ektronix, Inc.

WARRANTY

T ektronix warrants that the products that it manufactures and sells will be free from defects in materials and workmanship for a period of one (1) year from the date of shipment. If a product proves defective during this warranty period, T ektronix, 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.

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 T ektronix, 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 T ektronix 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. T ektronix shall not be obligated to furnish service under this warranty a) to repair damage resulting from attempts by personnel other than T ektronix 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-T ektronix 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 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 CUST OMER 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.

Contacting Tektronix

Phone 1-800-833-9200*

Address Tektronix, Inc.

Department or name (if known) 14200 SW Karl Braun Drive P.O. Box 500 Beaverton, OR 97077 USA

Web site www.tektronix.com

Sales support 1-800-833-9200, select option 1*

Service support 1-800-833-9200, select option 2*

Technical support Email: techsupport@tektronix.com

1-800-833-9200, select option 3* 1-503-627-2400

6:00 a.m. – 5:00 p.m. Pacific time

* This phone number is toll free in North America. After office hours, please

leave a voice mail message. Outside North America, contact a Tektronix sales office or distributor; see the Tektronix web site for a list of offices.

General Information vii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Installation and Repacking viii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Safety Summary xi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operating Instructions 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Overview 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Preparing to Use the 1502C 1–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Display 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Front-Panel Controls 1–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Menu Selections 1–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

T est Preparations 1–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cable T est Procedure 1–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Additional Features (Menu Selected) 1–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operator Tutorial 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

What is the Tektronix 1502C? 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

How Does It Do It? 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

You, the Operator 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Menus and Help 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Getting Started 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The Waveform Up Close 2–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A Longer Cable 2–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Ohms-at-Cursor 2–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Noise 2–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Set Ref (Delta Mode) 2–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

VIEW INPUT 2–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

STORE and VIEW STORE 2–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

VIEW DIFF 2–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Menu-Accessed Functions 2–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TDR Questions and Answers 2–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Options and Accessories 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Option 04: YT-1 Chart Recorder 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Option 05: Metric Default 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Option 07: YT-1S Chart Recorder 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Power Cord Options 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

T est data record Option 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Option DE 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Accessories 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Appendix A: Specifications A–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Electrical Characteristics A–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Environmental Characteristics A–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Certifications and Compliances A–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Physical Characteristics A–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Appendix B: Operator Performance Checks B–1. . . . . . . . . . . . . . . . . . . .

Appendix C: Operator Troubleshooting C–1. . . . . . . . . . . . . . . . . . . . . . . .

Error Messages C–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Appendix D: Application Note D–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Pulse Echo Testing of Electrical Transmission Lines

Using the Tektronix Time-Domain Reflectometry Slide Rule D–1. . . . . . . . . . .

T erms and Symbols D–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Relationships D–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

VSWR vs. Percent Reflected Voltage D–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Return Loss (dB) vs. Percent Reflected Voltage D–3. . . . . . . . . . . . . . . . . . . . . . . . .

Percent Reflected Voltage vs. Characteristic Line Impedance D–4. . . . . . . . . . . . . .

Percent Reflected Voltage vs. Load Resistance D–6. . . . . . . . . . . . . . . . . . . . . . . . . .

Characteristic Line Impedance or Load Resistance vs. Reflection Amplitude D–6. .

Centimeters vs. Inches or Meters vs. Feet D–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Dielectric Constant vs. Velocity Factor D–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Time vs. Short Distances, in Centimeters or Inches (any dielectric) D–8. . . . . . . . . .

Time vs. Long Distances, in Meters or Feet (any dielectric) D–9. . . . . . . . . . . . . . . .

Glossary Index

1502C MTDR User Manual

List of Figures

Table of Contents

Figure 1–1: Rear Panel Voltage Selector, Fuse, AC Receptacle 1–2. . . . .

Figure 1–2: Display Showing Low Battery Indication 1–3. . . . . . . . . . . . .

Figure 1–3: 1502C Front-Panel Controls 1–5. . . . . . . . . . . . . . . . . . . . . . .

Figure 1–4: Display and Indicators 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 1–5: Vp Set at .30, Cursor Beyond Reflected Pulse

(Set Too Low) 1–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 1–6: Vp Set at .99, Cursor Less Than Reflected Pulse

(Set Too High) 1–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 1–7: Vp Set at .66, Cursor at Reflected Pulse

(Set Correctly) 1–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 1–8: 20-ft Cable at 5 ft/div 1–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 1–9: Short in the Cable 1–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 1–10: Open in the Cable 1–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 1–11: 455-ft Cable 1–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 1–12: 455-ft Cable 1–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 1–13: Reflection Adjusted to One Division in Height 1–17. . . . . . .

Figure 1–14: Return Loss 1–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 1–15: Ohms-at-Cursor 1–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 1–16: Display with VIEW INPUT Turned Off 1–20. . . . . . . . . . . . .

Figure 1–17: Display of a Stored Waveform 1–20. . . . . . . . . . . . . . . . . . . . .

Figure 1–18: Display of a Stored Waveform 1–21. . . . . . . . . . . . . . . . . . . . .

Figure 1–19: Waveform Moved to Top Half of Display 1–22. . . . . . . . . . . .

Figure 1–20: Current Waveform Centered, Stored Waveform

Above 1–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 1–21: Current Waveform Center, Stored Waveform Above,

Difference Below 1–23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 1–22: Waveform of Three-Foot Lead-in Cable 1–24. . . . . . . . . . . .

Figure 1–23: Cursor Moved to End of Three-Foot Lead-in Cable 1–24. . . Figure 1–24: Cursor Moved to End of Three-Foot Lead-in Cable 1–25. . .

Figure 1–25: Cursor Moved to 0.00 ft 1–25. . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 1–26: Incident Pulse at Three Divisions 1–26. . . . . . . . . . . . . . . . . .

Figure 1–27: Waveform of Short 75 ohm Cable 1–27. . . . . . . . . . . . . . . . . .

Figure 1–28: Waveform Centered and Adjusted Vertically 1–27. . . . . . . .

Figure 1–29: Cursor Moved to Desired Position 1–28. . . . . . . . . . . . . . . . .

Figure 1–30: Waveform Viewed in Normal Operation 1–29. . . . . . . . . . . .

Figure 1–31: Waveform Showing Intermittent Changes 1–30. . . . . . . . . . .

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Figure 1–32: Waveform Display with No Outgoing Pulses 1–30. . . . . . . . .

Figure 1–33: A Captured Single Sweep 1–32. . . . . . . . . . . . . . . . . . . . . . . . .

Figure 2–1: Display Showing 3-ft Cable in Start-Up Conditions 2–3. . . .

Figure 2–2: Cursor of Rising Edge of Reflected Pulse 2–3. . . . . . . . . . . . .

Figure 2–3: Waveform with VERT SCALE Increased Showing

an Open 2–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 2–4: Waveform with Short 2–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 2–5: 3-foot Cable with Cursor at Far Left 2–5. . . . . . . . . . . . . . . .

Figure 2–6: 3-foot Cable with Cursor at Incident Pulse 2–6. . . . . . . . . . .

Figure 2–7: 3-foot Cable with Cursor at Incident Pulse, Vertical

Scale at 25 dB 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 2–8: Cursor on End of Longer Cable 2–7. . . . . . . . . . . . . . . . . . . .

Figure 2–9: Scrolling Down the Cable 2–8. . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 2–10: Ohms-at-Cursor 2–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 2–11: Ohms-at-Cursor Near Beginning of Cable 2–9. . . . . . . . . . .

Figure 2–12: Ohms-at-Cursor Beyond Reflected Pulse 2–10. . . . . . . . . . . .

Figure 2–13: Ohms-at-Cursor Beyond Reflected Pulse 2–10. . . . . . . . . . . .

Figure 2–14: Noise on the Waveform 2–11. . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 2–15: Noise Reduced 2–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 2–16: Noise Reduced to Minimum 2–12. . . . . . . . . . . . . . . . . . . . . . .

Figure 2–17: Incident and Reflected Pulses with Cursor at 0.00 ft 2–13. .

Figure 2–18: Cursor at 3.000 ft 2–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 2–19: New Zero Set at End of Test Cable 2–14. . . . . . . . . . . . . . . . .

Figure 2–20: Display with 3-ft Cable and NOISE FILTER turned to

VERT SET REF 2–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 2–21: VERT SCALE adjusted to Make Pulse Two Divisions

High 2–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 2–22: Display with VIEW INPUT Turned Off 2–17. . . . . . . . . . . . .

Figure 2–23: Display with VIEW INPUT Turned On 2–17. . . . . . . . . . . . .

Figure 2–24: Waveform Moved to Upper Portion of the Display 2–18. . . .

Figure 2–25: Waveform with Cable Shorted 2–19. . . . . . . . . . . . . . . . . . . .

Figure 2–26: Waveform with Both Current and Stored Waveforms 2–19.

Figure 2–27: Stored, Current, and Difference Waveforms 2–20. . . . . . . . .

Figure 2–28: Display with VIEW STORE and VIEW DIFF Disabled 2–21

Figure 2–29: Short and Open Viewed via Max Hold 2–22. . . . . . . . . . . . . .

Figure 2–30: Waveform Strobed Down Display in Max Hold 2–22. . . . . .

Figure 2–31: Display with Pulse Turned Off 2–24. . . . . . . . . . . . . . . . . . . .

Figure 2–32: Test Cable 2–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1502C MTDR User Manual

Table of Contents

Figure 2–33: Captured Single Sweep of Shorted Test Cable 2–25. . . . . . . .

Figure B–1: Start-up Measurement Display B–2. . . . . . . . . . . . . . . . . . . . .

Figure B–2: Measurement Display with 3-foot Cable B–3. . . . . . . . . . . . .

Figure B–3: Cursor at End of 3-foot Cable B–3. . . . . . . . . . . . . . . . . . . . . .

Figure B–4: Cursor at End of 3-foot Cable, Vp Set to .30 B–4. . . . . . . . . .

Figure B–5: Flat-Line Display Out to 50,0000+ Feet B–4. . . . . . . . . . . . . .

Figure B–6: Flat-Line Display at –2.000 ft B–5. . . . . . . . . . . . . . . . . . . . . .

Figure B–7: Waveform Off the Top of the Display B–5. . . . . . . . . . . . . . . .

Figure B–8: Waveform at the Bottom of the Display B–6. . . . . . . . . . . . . .

Figure B–9: Waveform with Gain at 5.00 mr/div B–6. . . . . . . . . . . . . . . . .

Figure B–10: Top of Pulse on Center Graticule B–8. . . . . . . . . . . . . . . . . .

Figure B–11: Rising Edge of Incident Pulse in Left-most Major

Division B–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure B–12: Waveform Centered, Cursor at 0.000 ft B–9. . . . . . . . . . . . .

Figure B–13: Pulse Centered on Display B–9. . . . . . . . . . . . . . . . . . . . . . . .

Figure B–14: Cursor on Lowest Major Graticule that Rising Edge

crosses B–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure B–15: Cursor on Highest Major Graticule that Rising Edge

crosses B–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure B–16: Jitter Apparent on Leading Edge of Incident Pulse B–11. . .

Figure B–17: Jitter Captured Using Max Hold B–11. . . . . . . . . . . . . . . . . .

Figure D–1: Slide Rule of VSWR vs. Percent Reflected Voltage D–2. . . .

Figure D–2: Slide Rule of Return Loss vs. Percent Reflected

Voltage D–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure D–3: Slide Rule 50 ohm Source D–4. . . . . . . . . . . . . . . . . . . . . . . . .

Figure D–4: Slide Rule 75 ohm Source D–5. . . . . . . . . . . . . . . . . . . . . . . . .

Figure D–5: Calculating Resistance/Impedance from Waveform

Amplitude D–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure D–6: English-Metric, Metric-English Conversion Scales D–7. . . .

Figure D–7: Dielectric Constant and Velocity Factor, Short

Distance D–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure D–8: Dielectric Constant and Velocity Factor, Long

Distance D–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1502C MTDR User Manual

Table of Contents

List of Tables

Table i: Shipping Carton Test Strength ix. . . . . . . . . . . . . . . . . . . . . . . .

Table 1–1: Fuse and Voltage Ratings 1–2. . . . . . . . . . . . . . . . . . . . . . . . . .

Table 1–2: Vp of Various Dielectric Types 1–12. . . . . . . . . . . . . . . . . . . . . .

Table A–1: Electrical Characteristics A–1. . . . . . . . . . . . . . . . . . . . . . . . . .

Table A–2: Environmental Characteristics A–3. . . . . . . . . . . . . . . . . . . . .

Table A–3: Physical Characteristics A–5. . . . . . . . . . . . . . . . . . . . . . . . . . .

1502C MTDR User Manual

General Information

Product Description

Battery Pack

Options

The Tektronix 1502C Metallic Time-Domain Reflectometer (MTDR) is a short-range cable tester capable of finding faults in metal cable. Tests can be made on coaxial, twisted pair, or parallel cable.

The 1502C sends an electrical pulse down the cable and detects any reflections made by discontinuities. This is known as time-domain reflectometry. The 1502C is sensitive to impedance changes. Problems in the cable will be detected and displayed as changes in impedance along the cable. These will be displayed as hills and valleys in the reflected pulse. The 1502C is capable of finding shorts, opens, defects in the shield, foreign substances in the cable (e.g., water), kinks, and more. Even though other instruments might show a cable as “good.” the 1502C can show many previously undetected faults.

The waveform may be temporarily stored within the 1502C and recalled or may be printed using the optional dot matrix strip chart recorder, which installs into the front-panel Option Port.

The 1502C may be operated from an AC power source or an internal lead-acid battery that supply a minimum of five hours operating time (see the Specifica- tions appendix for specifics).

Options available for the 1502C are explained in the Options and Accessories chapter of this manual.

Standards, Documents,

and References Used

Changes and History

Information

1502C MTDR User Manual

Terminology used in this manual is in accordance with industry practice. Abbreviations are in accordance with ANSI Y1.1–19722, with exceptions and additions explained in parentheses in the text. Graphic symbology is based on ANSI Y32.2–1975. Logic symbology is based on ANSI Y32.14–1973 and manufacturer’s data books or sheets. A copy of ANSI standards may be obtained from the Institute of Electrical and Electronic Engineers, 345 47th Street, New York, NY 10017.

Changes that involve manual corrections and/or additional data will be incorporated into the text and that page will show a revision date on the inside bottom edge. History information is included in any diagrams in gray.

vii

General Information

Installation and Repacking

Unpacking and Initial

Inspection

Power Source and Power

Requirements

Before unpacking the 1502C from its shipping container or carton, inspect for signs of external damage. If the carton is damaged, notify the carrier. The shipping carton contains the basic instrument and its standard accessories. Refer to the replaceable parts list in the Service Manual for a complete listing.

If the contents of the shipping container are incomplete, if there is mechanical damage or defect, or if the instrument does not meet operational check requirements, contact your local Tektronix Field Office or representative. If the shipping container is damaged, notify the carrier as well as Tektronix.

The instrument was inspected both mechanically and electrically before shipment. It should be free if mechanical damage and meet or exceed all electrical specifications. Procedures to check operational performance are in the Performance Checks appendix. These checks should satisfy the requirements for most receiving or incoming inspections.

The 1502C is intended to be operated from a power source that will not apply more than 250 volts RMS between the supply conductors or between either supply conductor and ground. A protective ground connection, by way of the grounding conductor in the power cord, is essential for safe operation.

The AC power connector is a three-way polarized plug with the ground (earth) lead connected directly to the instrument frame to provide electrical shock protection. If the unit is connected to any other power source, the unit frame must be connected to earth ground.

Repacking for Shipment

viii

Power and voltage requirements are printed on the back panel. The 1502C can be operated from either 115 VAC or 230 VAC nominal line voltage at 45 Hz to 440 Hz, or a battery pack.

Further information on the 1502C power requirements can be found in the Safety Summary in this section and in the Operating Instructions chapter.

When the 1502C is to be shipped to a Tektronix Service Center for service or repair, attach a tag showing the name and address of the owner, name of the individual at your firm who may be contacted, the complete serial number of the instrument, and a description of the service required. If the original packaging is unfit for use or is not available, repackage the instrument as follows:

1. Obtain a carton of corrugated cardboard having inside dimensions that are at

least six inches greater than the equipment dimensions to allow for cushioning. The test strength of the shipping carton should be 275 pounds (102.5 kg). Refer to the following table for test strength requirements:

1502C MTDR User Manual

General Information

T able i: Shipping Carton Test Strength

Gross Weight (lb) Carton Test Strength (lb)

0 – 10 200 11 – 30 275 31 – 120 375 121 – 140 500 141 – 160 600

2. Install the front cover on the 1502C and surround the instrument with

polyethylene sheeting to protect the finish.

3. Cushion the instrument on all sides with packing material or urethane foam

between the carton and the sides of the instrument.

4. Seal with shipping tape or an industrial stapler. If you have any questions, contact your local Tektronix Field Office or represen-

tative.

1502C MTDR User Manual

General Information

1502C MTDR User Manual

General Safety Summary

The safety information in this summary is for operating personnel. Specific warnings and cautions will be found throughout the manual where they apply, but might not appear in this summary. For specific service safety information, see the 1502C Service Manual.

Safety Terms and Symbols

Terms 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.

Terms 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 in the Manual:

1502C MTDR User Manual

WARNING or CAUTION

Information

Symbols on the Product:

DANGER

High Voltage

Protective Ground

(Earth) T erminal

ATTENTION

Refer to

Manual

Double

Insulated

General Safety Summary

Power Source

Grounding the Product

Danger Arising from Loss

of Ground

Use the Proper Power

Cord

This product is intended to operate from a power source that will not apply more than 250 volts RMS between the supply conductors or between the supply conductor and ground. A protective ground connection, by way of the grounding conductor in the power cord, is essential for safe operation.

This product is grounded through the grounding conductor of the power cord. To avoid electrical shock, plug the power cord into a properly wired receptacle before connecting to the product input or output terminals. A protective ground connection by way of the grounding conductor in the power cord is essential for safe operation.

Upon loss of the protective-ground connection, all accessible conductive parts (including knobs and controls that appear to be insulating) can render an electric shock.

Use only the power cord and connector specified for this product. Do not use this instrument without a rated AC line cord.

The standard power cord (161-0288-00) is rated for outdoor use. All other

optional power cords are rated for indoor use only.

Use the Proper Fuse

Do Not Operate in

Explosive Atmosphere

Do Not Remove Covers or

Panels

Connecting Cables to the

Front-Panel BNC

Disposal of Batteries

Use only a power cord that is in good condition. Refer cord and connector changes to qualified service personnel.

To avoid fire hazard, use only a fuse of the correct type. Refer fuse replacement to qualified service personnel.

To avoid explosion, do not operate this product in an explosive atmosphere unless it has been specifically certified for such operation.

To avoid personal injury, do not remove the product covers or panels. Do not operate the product without the covers and panels properly installed.

To avoid possible damage to the front-end circuitry, connection of a cable that is, or can be, driven by active circuitry should be avoided if the voltage could exceed 400 V.

This instrument contains a lead-acid battery. Some states and/or local jurisdictions might require special disposition/recycling of this type of material in accordance with Hazardous Waste guidelines. Check your local and state regulations prior to disposing of an old battery.

xii

1502C MTDR User Manual

General Safety Summary

Tektronix Factory Service will accept 1502C batteries for recycling. If you choose to return the battery to us for recycling, the battery cases must be intact, the battery should be packed with the battery terminals insulated against possible short-circuits, and should be packed in shock-absorbant material.

Tektronix, Inc. Attn: Service Department P.O. Box 500 Beaverton, Oregon 97077 U.S.A.

For additional information, phone:1–800–TEK–WIDE

1502C MTDR User Manual

xiii

General Safety Summary

xiv

1502C MTDR User Manual

Operating Instructions

Overview

Handling

Powering the 1502C

The 1502C front panel is protected by a watertight cover, in which the standard accessories are stored. Secure the front cover by snapping the side latches outward. If the instrument is inadvertently left on, installing the front cover will turn off the POWER switch automatically.

The carrying handle rotates 325° and serves as a stand when positioned beneath the instrument.

Inside the case, at the back of the instrument, is a moisture-absorbing canister containing silica gel. In extremely wet environments, it might be be necessary to periodically remove and dry the canister. This procedure is explained in the 1502C Service Manual.

The 1502C can be stored in temperatures ranging from –62° C to +85° C if a battery is not installed. If a battery is installed and the storage temperature is below –35° C or above +65° C, the battery pack should be removed and stored separately (see 1502C Service Manual for instructions on removing the battery). Battery storage temperature should be between –35° C to +65° C.

In the field, the 1502C can be powered using the internal battery. See Figure 1–1. For AC operation, check the rear panel for proper voltage setting. The voltage selector can be seen through the window of the protective cap. If the setting differs from the voltage available, it can be easily changed. Simply remove the protective cap and select the proper voltage using a screwdriver.

1502C MTDR User Manual

The 1502C is intended to be operated from a power source that will not apply more than 250 V RMS between the supply conductors or between either supply conductor and ground. A protective ground connection by way of the grounding conductor in the power cord is essential for safe operation.

The AC power connector is a three-way polarized plug with the ground (earth) lead connected to the instrument frame to provide electrical shock protection. If the unit is connected to any other power source, the unit frame must be connected to an earth ground. See Safety and Installation section.

CAUTION. If you change the voltage selector, you must change the line fuse to the appropriate value as listed near the fuse holder and in the table below.

1–1

Operating Instructions

REMOVE

CAP TO SELECT

VOLTAGE

REMOVE CAP TO

REPLACE

FUSE

Voltage Selector

Line Fuse

AC Power Cord Receptacle

Figure 1–1: Rear Panel V oltage Selector, Fuse, AC Receptacle

T able 1–1: Fuse and Voltage Ratings

Fuse Rating Voltage Rating

250 V Nominal Range

0.3 AT 115 VAC (90 – 132 V AC)

0.15 AT 230 VAC (180 – 250 VAC)

Care of the Battery Pack

1–2

CAUTION. Read these instructions concerning the care of the battery pack. They contain instructions that reflect on your safety and the performance of the instrument.

The 1502C can be powered by a rechargeable lead-gel battery pack that is accessible only by removing the case from the instrument. When AC power is applied, the battery pack is charged at a rate that is dependent on the battery charge state.

The battery pack will operate the 1502C for a minimum of eight continuous hours (including making 30 chart recordings) if the LCD backlight is turned off.

1502C MTDR User Manual

Operating Instructions

Battery Charging

The battery pack will charge fully in 16 hours when the instrument is connected, via the power cord, to an AC power source with the instrument turned off. The instrument may be turned on and operated while the batteries are charging, but this will increase the charging time. For longest battery life, a full charge is preferred over a partial charge.

For maximum capacity, the batteries should be charged within a temperature range of +20° C to +25° C. However, the batteries can be charged within a temperature range of 0° C to +40° C and operated in temperatures ranging from –10° C to +55° C.

CAUTION. Do not charge battery pack below 0° C or above +40° C. Do not discharge battery pack below –10° C or above +55° C. If removing the battery pack during or after exposure to these extreme conditions, turn the instrument off and remove the AC power cord.

The battery pack should be stored within a temperature range of –35° C to +65° C. However, the self-discharge rate will increase as the temperature increases.

If the instrument is stored with the battery pack installed, the battery pack should be charged every 90 days. A fully charged battery pack will lose about 12% of its capacity in three to four months if stored between +20° C and +25° C.

Low Battery

If the battery is low, it will be indicated on the LCD (bat/low). If this is the case, protective circuitry will shut down the 1502C within minutes. Either switch to AC power or work very fast. If the instrument is equipped with a chart recorder, using the recorder will further reduce the battery level, or the added load might shut down the instrument.

bat/low 0.00 ft

O N

F F

1 avg

500 mr 500 ft

Low Battery Indicator

Figure 1–2: Display Showing Low Battery Indication

1502C MTDR User Manual

1–3

Operating Instructions

Protection circuits in the charger prevent deep discharge of the batteries during instrument operation. The circuits automatically shut down the instrument whenever battery voltage falls below approximately 10 V. If shutdown occurs, the batteries should be fully recharged before further use.

NOTE. Turn the POWER switch off after instrument shutdown to prevent continued discharge of the batteries.

Low Temperature

Operation

When the instrument is stored at temperatures below –10° C, voids might develop in the liquid crystal display (LCD). These voids should disappear if the instrument is placed in an ambient temperature ≥ +5° C for 24 hours.

When operating the 1502C in an environment below +10° C, a heater will activate. The element is built into the LCD module and will heat the display to permit normal operation. Depending on the surrounding temperature, it might take up to 15 minutes to completely warm the crystals in the LCD. Once warmed, the display will operate normally.

1–4

1502C MTDR User Manual

Preparing to Use the 1502C

Check the power requirements, remove the front cover, and you are ready to test cables. The following pages explain the front-panel controls.

Operating Instructions

0.2 ft

METALLIC TDR CABLE TESTER

POSITION

.04

.05

.03

.06

.07

.02

.08

.01

.09

.00

POWER

(PULL ON)

VIEW

INPUT

VIEW

STORE

VIEW DIFF

STORE

DO NOT APPLY

EXT VOLTAGE

Tektronix

1502C

ac 0.00 ft

O N

O F F

1 avg

NOISE FILTER VERT SCALE DIST/DIV

HORZ VERT

500 mr

SET REF

3 4 5 6

Figure 1–3: 1502C Front-Panel Controls

CAUTION. Do not connect live circuits to the CABLE connector. Voltages exceeding 5 volts can damage the pulser or sampler circuits.

Bleed the test cable of any residual static charge before attaching it to the instrument. T o bleed the cable, connect the standar d 50 W terminator and standard female-to-female BNC connector together, then temporarily attach both to the cable. Remove the connectors before attaching the cable to the instrument.

When testing receiving antenna cables, avoid close proximity to transmitters. Voltages may appear on the cable if a nearby transmitter is in use, resulting in damage to the instrument. Before testing, be sure that there are no RF voltages present, or disconnect the cable at both ends.

1502C MTDR User Manual

1–5

Operating Instructions

Display

View Input

Indicator

View Store

Indicator

View Difference

Indicator

Store

Indicator

Power

Type

Waveform Cursor

1 avg

Selected

Noise Filter

Vertical Scale

500 mr 0.2 ft

Selected

Figure 1–4: Display and Indicators

Front-Panel to Cursor

Distance Window

0.00 ft

Grid

Selected

Distance per

Division

1–6

1502C MTDR User Manual

Front-Panel Controls

Operating Instructions

1. CABLE: A female BNC connector for attaching a cable to the 1502C for

testing.

NOISE FILTER

HORZ

VERT

SET REF

VERT SCALE

DIST/DIV

2. NOISE FILTER: If the displayed waveform is noisy, the apparent noise can

be reduced by using noise averaging. Averaging settings are between 1 and

128. The time for averaging is directly proportional to the averaging setting

chosen. A setting of 128 might take the instrument up to 35 seconds to

acquire and display a waveform. The first two positions on the NOISE

FILTER control are used for setting the vertical and horizontal reference

points. The selected value or function is displayed above the control on the

LCD.

3. VERT SCALE: This control sets the vertical sensitivity, displayed in mr

per division, or the vertical gain, displayed in dB. Although the instrument

defaults to millirho, you may choose the preferred mode from the Setup

Menu. The selected value is displayed above the control on the LCD.

4. DIST/DIV: Determines the number of feet (or meters) per division across

the display. The minimum setting is 0.1 ft/div (0.025 meters) and the

maximum setting is 200 ft/div (50 meters). The selected value is displayed

above the control on the LCD.

A standard instrument defaults to ft/div. A metric instrument (Option 05)

defaults to m/div, but either may be changed temporarily from the menu. The

default can be changed by changing an internal jumper (see 1502C Service

Manual and always refer such changes to qualified service personnel).

.4 .5

POWER

(PULL ON)

n o

.03

.02

.01

.9 .00

POSITION

.04 .05

.06

.07

.08

.09

1502C MTDR User Manual

5. Vp: The two Velocity of Propagation controls are set according to the

propagation velocity factor of the cable being tested. For example, solid

polyethylene commonly has a Vp of 0.66. Solid polytetraflourethylene

(Teflon ) is approximately 0.70. Air is 0.99. The controls are decaded: the

left control is the first digit and the right control is the second digit. For

example, with a Vp of 0.30, the first knob would be set to .3 and the second

knob to .00.

6. POWER: Pull for power ON and push in for power OFF. When the front

cover is installed, this switch is automatically pushed OFF.

POSITION: This is a continuously rotating control that positions the

displayed waveform vertically, up or down the LCD.

POSITION: This is a continuously rotating control that moves a

vertical cursor completely across the LCD graticule. In addition, the

waveform is also moved when the cursor reaches the extreme right or left

side of the display. A readout (seven digits maximum) is displayed in the

1–7

Operating Instructions

upper right corner of the LCD, showing the distance from the front panel BNC to the current cursor location.

VIEW INPUT

VIEW

STORE

VIEW

DIFF

STORE

Menu Selections

9. MENU: This pushbutton provides access to the menus and selects items

chosen from the menus.

10. VIEW INPUT: When pushed momentarily, this button toggles the display

of the waveform acquired at the CABLE connector. This function is useful to stop displaying a current waveform to avoid confusion when looking at a stored waveform. This function defaults to ON when the instrument is powered up.

11. VIEW STORE: When pushed momentarily, this button toggles the display

of the stored waveform.

12. VIEW DIFF: When pushed momentarily, this button toggles the display of

the current waveform minus the stored waveform and shows the difference between them.

13. STORE: When pushed momentarily, the waveform currently displayed will

be stored in the instrument memory. If a waveform is already stored, pushing this button will erase it. The settings of the stored waveform are available from the first level menu under View Stored Waveform Settings.

Main Menu

There are several layers of menu, as explained below.

The Main Menu is entered by pushing the MENU button on the front panel.

1. Return to Normal Operations puts the instrument into normal operation

mode.

2. Help with Instrument Controls explains the operation of each control.

When a control or switch is adjusted or pushed, a brief explanation appears on the LCD.

3. Cable Information has these choices: a. Help with Cables gives a brief explanation of cable parameters. b. Velocity of Propagation Values displays a table of common dielectrics

and their Vp values. These are nominal values. The manufacturer’s listed specifications should be used whenever possible.

c. Impedance Values displays impedances of common cables. In some

cases, these values have been rounded off. Manufacturer’s specifications should be checked for precise values.

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1502C MTDR User Manual

Operating Instructions

d. Finding Unknown Vp Values describes a procedure for finding an

unknown Vp.

4. Setup Menu controls the manner in which the instrument obtains and

displays its test results.

a. Acquisition Control Menu has these choices:

i. Max Hold Is: On/Off. Turn Max Hold on by pushing MENU then

STORE. In this mode, waveforms are accumulated on the display . Max Hold can be deactivated by pushing STORE or the mode exited by using the Setup Menu.

ii. Pulse Is: On/Off. T urns the pulse generator of f so the 1502C does not

send out pulses.

iii. Single Sweep Is: On/Off. This function is much like a still camera; it

will acquire one waveform and hold it.

b. Ohms-at-Cursor is: On/Off. When activated, the impedance at thee

point of the cursor is displayed beneath the distance window on the display.

c. Vertical Scale Is: dB/mr. This offers you a choice as to how the vertical

gain of the instrument is displayed. You may choose decibels or millirho. When powered down, the instrument will default to millirho when powered back up.

d. Distance/Div Is: ft/m. Offers you a choice of how the horizontal scale is

displayed. You may choose from feet per division or meters per division. When powered up, the instrument will default to feet unless the internal jumper has been moved to the meters position. Instructions on changing this default are contained in the 1502C Service Manual.

e. Light Is: On/Off. This control turns the electroluminescent backlight

behind the LCD on or off.

5. Diagnostics Menu lists an extensive selection of diagnostics to test the

operation of the instrument.

NOTE. The Diagnostics Menu is intended for instrument repair and calibration. Proper instrument setup is important for correct diagnostics results. Refer to the 1502C Service Manual for more information on diagnostics.

a. Service Diagnostics Menu has these choices:

1502C MTDR User Manual

i. Sampling Efficiency Diagnostic displays a continuous efficiency

diagnostic of the sampling circuits.

1–9

Operating Instructions

ii. Noise Diagnostic measures the internal RMS noise levels of the

instrument.

iii. Offset/Gain Diagnostic reports out-of-tolerance steps in the program-

mable gain stage. This can help a service technician to quickly isolate the cause of waveform distortion problems.

iv. RAM/ROM Diagnostics Menu performs tests on the RAM (Random

Access Memory) and the ROM (Read Only Memory).

v. Timebase Is: Normal - Auto Correction / Diagnostic - No

Correction. When in Normal - Auto Correction, the instrument

compensates for variations in temperature and voltage. This condition might not be desirable while calibrating the instrument. While in Diagnostic - No Correction, the circuits will not correct for these variations.

b. Front Panel Diagnostics aids in testing the front panel. c. LCD Diagnostics Menu has these choices:

i. LCD Alignment Diagnostic generates a dot pattern of every other

pixel on the LCD. These pixels can be alternated to test the LCD.

ii. Response Time Diagnostic generates alternate squares of dark and

light, reversing their order. This tests the response time of the LCD and can give an indication of the effectiveness of the LCD heater in a cold environment.

iii. LCD Drive Test Diagnostic generates a moving vertical bar pattern

across the LCD.

iv. Contrast Adjust allows you to adjust the contrast of the LCD. It

generates an alternating four-pixel pattern. The nominal contrast is set internally . When in Contrast Adjust mode, VERT SCALE is used as the contrast adjustment control. This value ranges from 0 to 255 units and is used by the processor to evaluate and correct circuit variations caused by temperature changes in the environment. When the diagnostic menu is exited, the LCD contrast returns to that set by internal adjust.

d. Chart Diagnostics Menu offers various tests for the optional chart

recorder. i. LCD Chart allows adjusting the number of dots per segment and the

number of prints (strikes) per segment.

1–10

ii. Head Alignment Chart generates a pattern to allow mechanical

alignment of the optional chart recorder.

1502C MTDR User Manual

Operating Instructions

6. View Stored Waveform Settings displays the instrument settings for the

stored waveform.

7. Option Port Menu contains three items. Two items allow configuration of

the option port for communicating with devices other than the optional chart recorder and one item test the option port.

a. Option Port Diagnostic creates a repeating pattern of signals at the

option port to allow service technicians to verify that all signals are present and working correctly.

b. Set Option Port Timing allows adjustment of the data rate used to

communicate with external devices. The timing rate between bytes can be set from about 0.05 to 12.8 milliseconds.

c. Option Port Debugging Is Off/On. Off is quiet, On is verbose. This

chooses how detailed the error message reporting will be when communicating with an external device.

It is possible to connect the instrument to a computer through a parallel interface with a unique software driver. Because different computers vary widely in processing speed, the instrument must be able to adapt to differing data rates while communicating with those computers. With user-developed software drivers, the ability to obtain detailed error messages during the development can be very useful. For more information, contact your Tektronix Customer Service representatives. They have information describing the option port hardware and software protocol and custom development methods available.

The SP-232, a serial interface product, also allows for connection of the 1502C to other instrumentation, including computers, via the option port. SP-232 is an RS-232C-compatible interface. For more information, contact your Tektronix Customer Service Representative. They can provide you with additional details on the hardware and software protocol.

8. Display Contrast (Software Version 5.02 and above) a. Press the MENU button firmly once. If the display is very light or very

dark, you might not be able to see a change in the contrast.

b. Turn the VERTICAL SCALE knob slowly clockwise to darken the

display or counterclockwise to lighten the display. If you turn the knob far enough, the contrast will wrap from the darkest to lightest value.

c. When the screen is clearly readable, press the MENU button again to

return to normal measurement operation. The new contrast value will remain in effect until the instrument is turned off.

1502C MTDR User Manual

1–11

Operating Instructions

Test Preparations

The Importance of Vp

(Velocity of Propagation)

Vp is the speed of a signal down the cable given as a percentage of the speed of light in free space. It is sometimes expressed as a whole number (e.g., 66) or a percentage (e.g., 66%). On the 1502C, it is the percentage expressed as a decimal number (e.g., 66% = .66). If you do not know the velocity of propagation, you can get a general idea from the following table, or use the Help with Cables section of the Cable Information menu. You can also find the Vp with the procedure that follows using a cable sample.

NOTE. If you do not know the Vp of your cable, it will not prevent you from finding a fault in your cable. However, if the Vp is set wrong, the distance readings will be affected.

All Vp settings should be set for the cable under test, not the supplied jumper cable.

T able 1–2: Vp of Various Dielectric Types

Dielectric Probable Vp

Jelly Filled .64 Polyethylene (PIC, PE, or SPE) .66 PTFE (Teflon R) or TFE .70 Pulp Insulation .72 Foam or Cellular PE (FPE) .78 Semi-solid PE (SSPE) .84 Air (helical spacers) .98

Finding an Unknown Vp

1. Obtain a known length of cable of the exact type you wish to test. Attach the

cable to the CABLE connector on the front panel.

2. Pull POWER on.

3. Turn the DIST/DIV to an appropriate setting (e.g., if trying to find the Vp of

a three-foot cable, turn the DIST/DIV to 1 ft/div).

4. Turn the

POSITION control until the distance reading is the same as the

known length of this cable.

5. Turn the Vp controls until the cursor is resting on the rising portion of the

reflected pulse. The Vp controls of the instrument are now set to the Vp of the cable.

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1502C MTDR User Manual

+ 96 hidden pages