User Manual 1502C Metallic Time-Domain Reflectometer 070-7169-05 This document applies for firmware version 5.04 and above. www.tektronix.
Copyright © Tektronix, Inc. All rights reserved. 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, Inc., P.O. Box 500, Beaverton, OR 97077 TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.
WARRANTY Tektronix 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, 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.
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.
Table of Contents 1502C MTDR User Manual General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Installation and Repacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii Safety Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi 1–1 Overview . . . . . . . . . . . . . .
Table of Contents Appendix D: Application Note . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D–1 Pulse Echo Testing of Electrical Transmission Lines Using the Tektronix Time-Domain Reflectometry Slide Rule . . . . . . . . . . . Terms and Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Relationships . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VSWR vs.
Table of Contents List of Figures Figure 1–1: Rear Panel Voltage Selector, Fuse, AC Receptacle . . . . . Figure 1–2: Display Showing Low Battery Indication . . . . . . . . . . . . . Figure 1–3: 1502C Front-Panel Controls . . . . . . . . . . . . . . . . . . . . . . . Figure 1–4: Display and Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 1–5: Vp Set at .30, Cursor Beyond Reflected Pulse (Set Too Low) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table of Contents iv Figure 1–32: Waveform Display with No Outgoing Pulses . . . . . . . . . Figure 1–33: A Captured Single Sweep . . . . . . . . . . . . . . . . . . . . . . . . . 1–30 1–32 Figure 2–1: Display Showing 3-ft Cable in Start-Up Conditions . . . . Figure 2–2: Cursor of Rising Edge of Reflected Pulse . . . . . . . . . . . . . Figure 2–3: Waveform with VERT SCALE Increased Showing an Open . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table of Contents Figure 2–33: Captured Single Sweep of Shorted Test Cable . . . . . . . . Figure B–1: Start-up Measurement Display . . . . . . . . . . . . . . . . . . . . . Figure B–2: Measurement Display with 3-foot Cable . . . . . . . . . . . . . Figure B–3: Cursor at End of 3-foot Cable . . . . . . . . . . . . . . . . . . . . . . Figure B–4: Cursor at End of 3-foot Cable, Vp Set to .30 . . . . . . . . . . Figure B–5: Flat-Line Display Out to 50,0000+ Feet . . . . . . . . . . . . . .
Table of Contents List of Tables vi Table i: Shipping Carton Test Strength . . . . . . . . . . . . . . . . . . . . . . . . ix Table 1–1: Fuse and Voltage Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . Table 1–2: Vp of Various Dielectric Types . . . . . . . . . . . . . . . . . . . . . . 1–2 1–12 Table A–1: Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . Table A–2: Environmental Characteristics . . . . . . . . . . . . . . . . . . . . .
General Information Product Description 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.
General Information Installation and Repacking Unpacking and Initial Inspection 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.
General Information Table 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.
General Information x 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.
General Safety Summary Power Source 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. Grounding the Product This product is grounded through the grounding conductor of the power cord.
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.
General Safety Summary xiv 1502C MTDR User Manual
Operating Instructions Overview Handling 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.
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 Voltage Selector, Fuse, AC Receptacle Table 1–1: Fuse and Voltage Ratings Fuse Rating Voltage Rating 250 V Nominal Range 0.3 AT 115 VAC (90 – 132 VAC) 0.15 AT 230 VAC (180 – 250 VAC) Care of the Battery Pack CAUTION. Read these instructions concerning the care of the battery pack.
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.
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.
Operating Instructions 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. 7 8 9 Tektronix 10 ac MENU VIEW INPUT 11 VIEW STORE 12 VIEW DIFF 13 METALLIC TDR 1502C CABLE TESTER POSITION 0.00 ft O N POSITION O F F O F F STORE O F F 1 avg 500 mr DO NOT APPLY EXT VOLTAGE NOISE FILTER VERT SCALE 0.2 ft DIST/DIV .4 .3 HORZ VERT 1 SET REF 2 3 4 .5 Vp .04 .6 .03 .
Operating Instructions Display Power Type Waveform Front-Panel to Cursor Distance Window Cursor ac View Input Indicator O N View Store Indicator O F F View Difference Indicator O F F Store Indicator O F F 0.00 ft Grid 1 avg Selected Noise Filter 500 mr Selected Vertical Scale 0.
Operating Instructions Front-Panel Controls 1. CABLE: A female BNC connector for attaching a cable to the 1502C for testing. 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.
Operating Instructions upper right corner of the LCD, showing the distance from the front panel BNC to the current cursor location. MENU VIEW INPUT 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.
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.
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 programmable 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.
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.
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).
Operating Instructions The following three illustrations show settings too low, too high, and correct for a sample three-foot cable. ac 3.000 ft O N O F F O F F O F F Figure 1–5: Vp Set at .30, Cursor Beyond Reflected Pulse (Set Too Low) ac 3.000 ft O N O F F O F F O F F Figure 1–6: Vp Set at .99, Cursor Less Than Reflected Pulse (Set Too High) ac 3.000 ft O N O F F O F F O F F Figure 1–7: Vp Set at .
Operating Instructions Cable Test Procedure Distance to the Fault Be sure to read the previous paragraphs on Vp. 1. Set the 1502C controls: POWER CABLE NOISE FILTER VERT SCALE DIST/DIV Vp On Cable to BNC 1 avg 500 mr (see below) (per cable) 2. If you know approximately how long the cable is, set the DIST/DIV appropriately (e.g., 20-ft cable would occupy four divisions on the LCD if 5 ft/div was used). The entire cable should be displayed. ac 0.
Operating Instructions ac 20.000 ft O N O F F Short O F F O F F Figure 1–9: Short in the Cable When the entire cable is displayed, you can tell if there is an open or a short. Essentially, a large downward pulse indicates a short (see Figure 1–9), while a large upward pulse indicates an open (see Figure 1–10). Less catastrophic faults can be seen as smaller reflections. Bends and kinks, frays, water, and interweaving all have distinctive signatures. ac 20.
Operating Instructions ac 452.000 ft O N Open O F F O F F O F F Figure 1–11: 455-ft Cable n o 5. Change DIST/DIV to 20 ft/div. The entire cable can now be inspected in detail on the LCD. Turn the POSITION control so the cursor travels to the far right side of the LCD. Keep turning and the cable will be “dragged” across the display. ac 452.000 ft O N O F F Short O F F O F F Figure 1–12: 455-ft Cable A “rise” or “fall” is a signature of an impedance mismatch (fault).
Operating Instructions Reflection Coefficient Measurements The reflection coefficient is a measure of the impedance change at a point in the cable. It is the ratio of the signal reflected back from a point, divided by the signal going into that point. It is designated by the Greek letter r and is written in this manual as rho. The 1502C measures the reflection coefficient in millirho (thousandths of a rho). To measure a reflection, adjust VERT SCALE to make the reflection one division high.
Operating Instructions similar to the Vertical Compensation for Higher Impedance Cable procedure (see the VERT SET REF section). Return Loss Measurements Return loss is another was of measuring impedance changes in a cable. Mathematically, return loss is related to rho by the formula: Return Loss (in dB) = –20 * log (base ten) of Absolute Value of Rho (Vref/Vinc) The 1502C can be made to display in dB instead of mr/div through the menu: 1. Press MENU. 2. Select Setup Menu. 3. Press MENU again. 4.
Operating Instructions Ohms-at-Cursor The 1502C can compute and display what impedance mismatch would cause a reflection as high (or low) as the point at the cursor. This measurement is useful for evaluating the first impedance mismatch (first reflection) or small impedance changes along the cable (e.g., connectors, splices). This function can be selected in the Setup Menu. Once it is enabled, the impedance value will be displayed under the distance in the distance window. ac 2.
Operating Instructions Using VIEW INPUT When pushed, the VIEW INPUT button displays the input at the front panel CABLE connector. When VIEW INPUT is turned off and no other buttons are pushed, the display will not have a waveform on it (see Figure 1–16). The default condition when the instrument is powered up is to have VIEW INPUT on. ac 0.
Operating Instructions Using VIEW STORE The VIEW STORE button, when pushed on, displays the waveform stored in the memory as a dotted line. If there is no waveform in memory, a message appears on the LCD informing you of this. ac 3.000 ft O F F O N O F F O N Figure 1–18: Display of a Stored Waveform Using VIEW DIFF When pushed on, the VIEW DIFF button displays the difference between the current waveform and the stored waveform as a dotted line. If no waveform has been stored, a message will appear.
Operating Instructions ac 3.000 ft O N O F F O F F O N Figure 1–19: Waveform Moved to Top Half of Display 2. Push STORE to capture the waveform. Remember, once it is stored, this waveform cannot be moved on the display. 3. Move the current waveform (the one you want to compare against the stored waveform) to the center of the display. 4. Push VIEW STORE and the stored waveform will appear above the current waveform. ac 3.
Operating Instructions ac 3.000 ft Stored Waveform VIEW STORE O N Current Waveform VIEW INPUT O N O N O N Difference VIEW DIFF Figure 1–21: Current Waveform Center, Stored Waveform Above, Difference Below Notice the VIEW INPUT waveform is solid, VIEW DIFF is dotted, and VIEW STORE is dot-dash. There are many situations where the VIEW DIFF function can be useful. One common situation is to store the waveform of a suspect cable, repair the cable, then compare the two waveforms after the repair.
Operating Instructions Using Horizontal Set Reference HORZ SET REF (D mode) allows you to offset the distance reading. For example, a lead-in cable to a switching network is three feet long and you desire to start the measurement after the end of the lead-in cable. HORZ SET REF makes it simple. ac 0.000 ft O N O F F O F F End of 3-ft cable O F F Figure 1–22: Waveform of Three-Foot Lead-in Cable 1. Turn the NOISE FILTER control to HORZ SET REF. The noise readout on the LCD will show: set D.
Operating Instructions 0.000 ft D ac O N O F F O F F O F F Figure 1–24: Cursor Moved to End of Three-Foot Lead-in Cable NOTE. Vp changes will affect where the reference is set on the cable. Be sure to set the Vp first, then set the delta to the desired location. 5. To exit HORZ SET REF, use the following procedure: a. Turn the NOISE FILTER control to HORZ SET REF. b. Turn DIST/DIV to .1 ft/div. If the distance reading is extremely high, you might want to use a higher setting initially, then turn to .
Operating Instructions Using Vertical Set Reference VERT SET REF works similar to HORZ SET REF except that it sets a reference for gain (pulse height) instead of distance. This feature allows zeroing the dB scale at whatever pulse height is desired. 1. Turn NOISE FILTER fully counterclockwise. “Set Ref” will appear in the noise averaging area of the LCD. 2. Adjust the incident pulse to the desired height (e.g., four divisions). It might be necessary to adjust n POSITION. o ac 0.
Operating Instructions ac 19.200 ft O N O F F O F F O F F Figure 1–27: Waveform of Short 75 ohm Cable n o 2. Adjust the screen. POSITION control to position the reflected pulse at center 3. Turn NOISE FILTER to VERT SET REF. 4. Adjust VERT SCALE so the reflected pulse (from open at far end of cable sample) is two divisions high. ac 19.200 ft O N O F F O F F O F F set vertical scale and press STORE Figure 1–28: Waveform Centered and Adjusted Vertically 5. Press STORE. 6.
Operating Instructions ac 1.840 ft O N O F F O F F O F F Figure 1–29: Cursor Moved to Desired Position The instrument is now set to measure reflections in millirho relative to the sample cable impedance. To measure reflections on a 50 W cable, the VERT SET REF must be reset. 8. To exit VERT SET REF, use the following procedure: a. Turn NOISE FILTER to VERT SET REF. b. Adjust VERT SCALE to obtain an incident pulse height of two divisions. c. Push STORE. d. Turn NOISE FILTER to desire filter setting.
Operating Instructions Additional Features (Menu Selected) Max Hold The 1502C will capture and store waveforms on an ongoing basis. This is useful when the cable or wire is subjected to intermittent or periodic conditions. The 1502C will monitor the line and display any fluctuations on the LCD. 1. Attach the cable to the 1502C front-panel CABLE connector. 2. Push MENU to access the main menu. 3. Scroll to Setup Menu and push MENU again. 4. Scroll to Acquisition Control Menu and push MENU again. 5.
Operating Instructions ac 0.000 ft O N Captured changes O N Figure 1–31: Waveform Showing Intermittent Changes 8. To exit monitor mode, push STORE again. 9. To exit Max Hold, access the Acquisition Control Menu again, turn off Max Hold, and push MENU repeatedly until the instrument returns to normal operation. Pulse On/Off This feature puts the 1502C in a “listening mode” by turning off the pulse generator. 1. Attach a cable to the 1502C front-panel CABLE connector. 2.
Operating Instructions 6. Repeatedly press MENU until the instrument returns to normal operation. CAUTION. This function is used mostly for troubleshooting by qualified technicians. It is not recommended that you use the 1502C as a stand-alone monitoring device. The input circuitry is very sensitive and can be easily damaged by even moderate level signals. NOTE. In this mode, the 1502C is acting as a detector only.
Operating Instructions ac 0.000 ft O F F O F F O F F O F F Figure 1–33: A Captured Single Sweep 8. To exit Single Sweep is: On, access the Acquisition Control Menu again, turn the Single Sweep back off, then repeatedly push MENU until the instrument returns to normal operation.
Operator Tutorial This chapter will show, step by step, the features and uses of the 1502C. What is the Tektronix 1502C? The Tektronix 1502C Metallic Time-Domain Reflectometer is a short range metallic cable tester capable of finding faults in metal cable. Tests can be made on coaxial cable, twisted pair, or parallel cable. How Does It Do It? The 1502C sends an electrical pulse down the cable and receives reflections back made by any discontinuities. This is known as time-domain reflectometry.
Operator Tutorial Getting Started Let’s start by inspecting a cable. For the next few examples, we will use the 3-foot precision test cable provided with the 1502C (Tektronix part number 012–1350–00). 1. Pull on the POWER switch. The instrument will initialize, give instructions for accessing the menu, and enter normal operation mode. 2. Set the 1502C front-panel controls to: CABLE NOISE FILTER VERT SCALE DIST/DIV Vp Attach 3-ft cable 1 avg 500 mr (default) 1 ft/div (0.25 m if using metric) .66 NOTE.
Operator Tutorial ac 0.000 ft O N O F F Figure 2–1: Display Showing 3-ft Cable in Start-Up Conditions n o 3. The rising pulse on the left is the test pulse (incident pulse) leaving the instrument. The rising reflected pulse on the right displays the echo coming back. Turn the POSITION control clockwise until the cursor rests on the rising edge of the reflected pulse. ac 3.
Operator Tutorial ac 3.000 ft O N Open O F F O F F O F F Figure 2–3: Waveform with VERT SCALE Increased Showing an Open 5. The n POSITION control moves the waveform up and down the display. o Adjust this for best viewing. 6. Short the end of the cable with an electrical clip or other suitable device. See the pulse take a dive? That is the classic signature of a short, a point of lower impedance. ac 3.
Operator Tutorial The Waveform Up Close It helps to know what makes up a pulse. Here is the waveform anatomy using the 3-foot test cable as an example: n o POSITION control counterclockwise until the distance window 1. Turn the reads –2.000 ft. The cursor will be on the far left side of the display and the reflected pulse will be near center. 2. Set the 1502C front-panel controls: CABLE NOISE FILTER VERT SCALE DIST/DIV Vp 3-ft test cable, no short 1 avg 500 mr 1 ft (0.25 m) .66 3.
Operator Tutorial ac –0.520 ft O N O F F O F F O F F Figure 2–6: 3-foot Cable with Cursor at Incident Pulse 5. Adjust the VERT SCALE control to approximately 25 mr. Adjust the n POSITION control to keep the middle portion of the pulse on the display. o The bumps following the incident pulse are the aberrations from the internal circuitry and reflections between the open end of the cable and the front panel. ac –0.
Operator Tutorial A Longer Cable Longer cables might not fit in the display. Let’s demonstrate that with a longer cable. Obtain a known length of 50 W cable. For this example, we are using a coaxial cable approximately 452 feet long. Your cable length will probably differ, but the following test procedure remains fundamentally correct for any cable length up to 2,000 feet. 1.
Operator Tutorial ac 362.800 ft Cursor O N O F F Cable Scrolling in this direction O F F O F F Figure 2–9: Scrolling Down the Cable NOTE. When testing a long cable, it is helpful to set DIST/DIV to a higher setting when scrolling to either end of the cable. For example, if testing a 1,500-ft cable, it would be very tiring to scroll the entire length from end to end at 1 ft/div. Ohms-at-Cursor Using the long cable as an example, we can find the impedance at the cursor. 1.
Operator Tutorial 50 W impedance plus 9.5 W series resistance. You can check this by putting a known reference on the end of the cable and measuring its impedance with ohms-at-cursor. The difference between the actual reading and the expected reference reading is the series resistance. ac 408.000 ft 59.5 W Ohms-at-Cursor Readout O N O F F O F F O F F Figure 2–10: Ohms-at-Cursor n o POSITION control to set the cursor near the beginning of the 7. Turn the cable.
Operator Tutorial ac 578.000 ft >=1 K W O N O F F O F F O F F Figure 2–12: Ohms-at-Cursor Beyond Reflected Pulse n o POSITION control to move the cursor to the far left side of the 9. Turn the display (–2.000 ft). Note that the ohms-at-cursor reading is now < 1 W. ac –2.000 ft <1 W O N O F F O F F O F F Figure 2–13: Ohms-at-Cursor Beyond Reflected Pulse If the cursor is placed too near a fault, the reflection will not have stabilized, which will make the ohms-at-cursor reading misleading.
Operator Tutorial Noise On a longer cable, “grass” might appear on the displayed waveform. This is primarily caused by the cable acting as an antenna, picking up nearby electrical noise. 1. Set the 1502C front-panel controls: n o CABLE NOISE FILTER VERT SCALE DIST/DIV Vp POSITION 3-ft cable 1 avg 500 mr 1 ft (0.25 m) .66 40.000 ft 2. Attach the 50 W terminator to the end of the test cable using the female-tofemale BNC adaptor (both of these items are supplied with the instrument). 3.
Operator Tutorial ac 40.000 ft O N O F F O F F O F F Figure 2–15: Noise Reduced 5. Increase the NOISE FILTER setting to 128. NOTE. The higher the setting, the more time the instrument takes to average the waveform. ac 40.000 ft O N O F F O F F O F F Figure 2–16: Noise Reduced to Minimum 6. Move the n POSITION control and notice how averaging restarts at a low o value to allow easy positioning. The 50 W terminator was used here because it gives a good impedance match.
Operator Tutorial Set Ref (Delta Mode) HORZ SET REF Horizontal Set Reference establishes the starting point at which the distance window begins reading the distance to the cursor. If, for example, you have a 3-foot cable leading to a patch panel, you could eliminate this jumper from your distance readings. 1. Set the 1502C front-panel controls to: CABLE NOISE FILTER VERT SCALE DIST/DIV Attach 3-ft cable 1 avg 500 mr (default) 1 ft/div (0.25 m) n o NOTE.
Operator Tutorial ac 3.000 ft O N O F F O F F return FILTER to desire setting . . . O F F Figure 2–18: Cursor at 3.000 ft 5. Turn the NOISE FILTER control to 1 avg. Note that the distance window now reads 0.00 ftD. This means that everything from the front panel BNC to the end of the cable is subtracted from the distance calculations. You have set zero at the far end of the test cable. 0.000 ft D ac O N O F F O F F O F F Figure 2–19: New Zero Set at End of Test Cable 6.
Operator Tutorial VERT SET REF This control is nearly the same as HORZ SET REF except it sets the vertical zero reference. It would be helpful to read the section of VERT SET REF in the Operating Instructions chapter to give you some technical background. The VERT SET REF function allows manual control of the vertical calibration of the 1502C. This can be used to compensate for cable loss or to increase the resolution of the millirho scale. The following example shows how to compensate for cable loss.
Operator Tutorial ac 0.000 ft O N O F F O F F O F F return FILTER to desired setting ... Figure 2–21: VERT SCALE adjusted to Make Pulse Two Divisions High 6. Return NOISE FILTER to the desired setting. The vertical scale now reads 500 mr/div. Return-loss measurements at the far end of the cable (or a similar cable in that bundle) can now be made using normal methods. To make measurements closer or farther from the instrument requires that you reset the VERT SET REF. NOTE.
Operator Tutorial VIEW INPUT This push button allows you to view what is coming in the CABLE connector, or to eliminate it from the display. 1. Set the 1502C front-panel controls to: CABLE NOISE FILTER VERT SCALE DIST/DIV Attach 3-ft cable 1 avg 500 mr 1 ft/div (0.25 m) 2. Press VIEW INPUT. The indicator block on the LCD should read OFF and the waveform should disappear from the display. ac 0.000 ft O F F O F F O F F O F F Figure 2–22: Display with VIEW INPUT Turned Off 3. Press VIEW INPUT again.
Operator Tutorial This function can be used to make the display less busy when viewing stored waveforms. STORE and VIEW STORE These functions allow you to store a waveform and view the stored waveform. 1. Set the 1502C front-panel controls to: CABLE NOISE FILTER VERT SCALE DIST/DIV Attach 3-ft cable 1 avg 500 mr 1 ft/div (0.25 m) 2. Make sure you have a waveform on the LCD, then adjust the n POSITION o control to place the waveform in the upper section of the display. ac 0.
Operator Tutorial ac 0.000 ft O N O F F O F F O N Figure 2–25: Waveform with Cable Shorted 7. Press VIEW STORE to view the stored waveform. What you see on the display is the waveform you stored previously with the open cable and the current waveform with the shorted cable. ac 0.
Operator Tutorial VIEW DIFF Press VIEW DIFF. This adds a waveform in the lower portion of the display that is the mathematical difference between the stored waveform and the current waveform. ac 0.000 ft O N O N O O FF N O N Difference VIEW DIFF Figure 2–27: Stored, Current, and Difference Waveforms NOTE. There must be a waveform stored before it can be compared by the VIEW DIFF function. Pressing this button with no waveform in storage will caused an error message to be displayed.
Operator Tutorial Menu-Accessed Functions NOTE. If you get lost or confused while in a menu, repeatedly press the MENU button until the instrument returns to normal operation mode. Max Hold 1. Set the 1502C front-panel controls to: CABLE NOISE FILTER VERT SCALE DIST/DIV Attach 3-ft cable 1 avg 500 mr (default) 1 ft/div (0.25 m) 2. Pull POWER on. 3. Press MENU to access the Main Menu. 4. Using the n POSITION control, scroll down to Setup Menu. o 5. Press MENU to accept this selection. 6.
Operator Tutorial 13. Press MENU again to enter normal operations mode. Note that the VIEW STORE and VIEW DIFF indicator blocks have disappeared. This tells you that both of these functions have been disabled. 14. Press STORE. This activates the Max Hold function. Notice that the STORE indicator block has darkened. 15. With a clip lead or other device, short the far end of the test cable, then remove the short. Note that both conditions now appear on the display. ac 0.
Operator Tutorial You can probably see how this function is useful for monitoring lines for changes over a period of time, or for intermittent conditions. For example: H A coastal phone line only has problems during high tide. Overnight monitoring reveals water in the line during the high tide period. H A data communications line is monitored for an intermittent short. Three days of monitoring reveals the shorts occur only during the hours of darkness. Rodents are found in the cable ducts.
Operator Tutorial ac 0.000 ft O N O F F O F F O F F Figure 2–31: Display with Pulse Turned Off CAUTION. This function is used mostly for troubleshooting by qualified technicians. It is not recommended that you use the 1502C as a stand-alone monitoring device. The input circuitry is very sensitive and can be easily damaged by even moderate level signals. 11. To turn the pulse back on, enter the Acquisition Control Menu again, scroll to Pulse is: Off and press MENU to turn the pulse back on.
Operator Tutorial 10. Press MENU repeatedly until the instrument returns to normal operation. The waveform on the display is the familiar test cable. ac 0.000 ft O N O F F O F F O N Figure 2–32: Test Cable 11. Short the far end of the test cable. 12. Press VIEW INPUT. The 1502C has done a single sweep, capturing just one frame. ac 0.000 ft O N O F F O F F O N Figure 2–33: Captured Single Sweep of Shorted Test Cable 13. Remove the short and notice that the waveform does not change. 14.
Operator Tutorial 15. To exit Single Sweep, access the Acquisition Control Menu again, toggle the Single Sweep is: line back to Off, then push the MENU button repeatedly until the instrument returns to normal operations. TDR Questions and Answers 2–26 Q1: What does TDR stand for? A1: Time-Domain Reflectometer. Q2: What is the difference between time domain and frequency domain? A2: Within the time domain, things are expressed in units of time (e.g., nanoseconds).
Operator Tutorial Q8: What is resistance? A8: Resistance is the opposition to DC current flow, or DC voltage divided by DC current. Q9: What is impedance? A9: Impedance is the total opposition (resistance plus reactance) a circuit offers to the flow of alternating current at a given frequency. Q10: What factors determine the resistance of a cable? A10: The cross sectional area (gauge), length, and the type of material the conductor is made of (usually copper).
Operator Tutorial 2–28 1502C MTDR User Manual
Options and Accessories The following options are available for the 1502C MTDR: Option 04: YT-1 Chart Recorder Option 04 instruments come equipped with a chart printer. Refer to the YT-1/ YT-1S Chart Recorder Instruction Manual that comes with this option for instructions on operation, paper replacement, and maintenance. Refer to the table on the following page for manual part numbers. Option 05: Metric Default Option 05 instruments will power up in the metric measurements mode.
Options and Accessories Test Data Record Option This option provides the test data record obtained during the Performance Verification of the instrument and is limited to the primary characteristics of this instrument type. Option DE German language firmware Tektronix part number 160-8999-xx.
Options and Accessories Connector, BNC female to Dual Banana Plug 103-0090-00 Connector, BNC male to Dual Binding Post 103-0035-00 Connector, BNC male to N female 103-0058-00 Connector, BNC female to N male 103-0045-00 Connector, BNC female to UHF male 103-0015-00 Connector, BNC female to UHF female 103-0032-00 Connector, BNC female to Type F male 103-0158-00 Connector, BNC male to Type F female 013-0126-00 Connector, BNC female to GR 017-0063-00 Connector, BNC male to GR 017-0064-00 Te
Options and Accessories 3–4 1502C MTDR User Manual
Appendix A: Specifications The tables in this chapter list the characteristics and features that apply to this instrument after it has had a warm-up period of at least five minutes. The Performance Requirement column describes the limits of the Characteristic. Supplemental Information describes features and typical values or other helpful information. Electrical Characteristics Table A–1: Electrical Characteristics Characteristic Performance Requirement Supplemental Information ≤200 ps (0.
Appendix A: Specifications Table A–1: Electrical Characteristics (Cont.) Characteristic Performance Requirement Supplemental Information 1.6 inches or ±1% of distance measured, whichever is greater For cables with Vp = 0.66 For delta mode measurements Error ≤0.5% for distance ≥27 ft Error ≤1.0% for distance ≥14 ft Error ≤2.0% for distance ≥7 ft Error ≤10% for distance ≥1.
Appendix A: Specifications Environmental Characteristics Table A–2: Environmental Characteristics Characteristic Performance Requirement Supplemental Information Operating –10°C to +55°C Battery capacity reduced at other than +15°C to +25°C Non-operating –62°C to +85°C With battery pack removed. Storage temp with battery pack in is –35°C to +65°C. Contents on non-volatile memory (stored waveform) might be lost at temps below –40°C.
Appendix A: Specifications Certifications and Compliances Category Standard or description EC Declaration of Conformity – Meets intent of Directive 89/336/EEC for Electromagnetic Compatibility.
Appendix A: Specifications Category Pollution Degree Standard or description A measure of the contaminates that could occur in the environment around and within a product. Typically the internal environment inside a product is considered to be the same as the external. Products should be used only in the environment for which they are rated. Pollution Degree 1 No pollution or only dry, nonconductive pollution occurs.
Appendix A: Specifications A–6 1502C MTDR User Manual
Appendix B: Operator Performance Checks This appendix contains performance checks for many of the functions of the 1502C. They are recommended for incoming inspections to verify that the instrument is functioning properly. Procedures to verify the actual performance requirements are provided in the 1502C Service Manual. Performing these checks will assure you that your instrument is in good working condition.
Appendix B: Operator Performance Checks off, these checks must be repeated again when the instrument is powered on again. Set Up Set the 1502C front-panel controls: NOISE FILTER VERT SCALE DIST/DIV Vp 1. Horizontal Scale (Timebase) Check 1 avg no adjustment 1 ft/div (0.25 m) .66 If the instrument fails this check, it must be repaired before any distance measurements can be made with it. 1. Turn the 1502C power on. The display should look very similar to Figure B–1. ac 0.
Appendix B: Operator Performance Checks ac 0.000 ft O N O F F O F F O F F Figure B–2: Measurement Display with 3-foot Cable n o POSITION control, measure the distance to the rising edge of 3. Using the the waveform at the open end of the cable. The distance shown on the display distance window (upper right corner of the LCD) should be from 2.87 to 3.13 feet (0.875 to 0.954 m). ac 3.000 ft O N O F F O F F O F F Figure B–3: Cursor at End of 3-foot Cable 4. Change the Vp to .30.
Appendix B: Operator Performance Checks ac 1.360 ft O N O F F O F F O F F Figure B–4: Cursor at End of 3-foot Cable, Vp Set to .30 6. Remove the 3-foot cable and connect the 50 W terminator. 7. Change the DIST/DIV to 200 ft/div (50 m/div) n o POSITION control clockwise until the distance window shows a 8. Turn the distance greater than 2,000 feet (> 600 m). The waveform should be a flat line from the pulse to this point. ac 2051.
Appendix B: Operator Performance Checks ac –2.000 ft O N O F F O F F O F F Figure B–6: Flat-Line Display at –2.000 ft This last step has set up the instrument for the next check. 2. Vertical Position (Offset) Check If the instrument fails this test, it can be used, but should be serviced when possible. Not all of the waveforms will be viewable at all gain settings. 1. Using the n o POSITION control, verify that the entire waveform can be moved to the very top of the display (off the graticule area).
Appendix B: Operator Performance Checks ac –2.000 ft O N O F F O F F Waveform O F F Figure B–8: Waveform at the Bottom of the Display 3. Noise Check If the instrument fails this check, it can still be usable for measurements of large faults that do not require a lot of gain, but send the instrument to be serviced when possible. A great deal of noise reduction can be made using the NOISE FILTER control. n o 1. Adjust the POSITION control to obtain 100.000 ft (30.500 m) in the distance window.
Appendix B: Operator Performance Checks 7. Press MENU again. 8. Using the n o POSITION control, select Noise Diagnostics. 9. Press MENU again and follow the instructions on the display. 10. Exit from Noise Diagnostics, but do not exit from the Service Diagnostic Menu yet. 4. Offset/Gain Check If the instrument fails this check, it should not be used for loss or impedance measurements. Send it to be serviced when possible. 1.
Appendix B: Operator Performance Checks 6. Aberrations Check If the aberrations are out of specification, the ohms-at-cursor function might be less accurate than specified. 1. Connect the 50 W precision terminator to the front-panel CABLE connector. 2. Set the DIST/DIV control to 5 ft/div (1 m/div). 3. Increase the VERT SCALE control to 50 mr/div. 4. Using the n o POSITION control, move the top of the pulse to the center graticule line. ac –1.
Appendix B: Operator Performance Checks All the aberrations, except the one under the cursor (see Figure B–12), must be within one division of the center graticule line from out to 10 feet (3.5 m) past the rising edge of the pulse. n o To verify distances past the right edge of the display, scroll along the waveform by turning the POSITION control clockwise. ac 0.000 ft O N O F F O F F O F F Figure B–12: Waveform Centered, Cursor at 0.000 ft 7.
Appendix B: Operator Performance Checks 3. Turn the VERT SCALE control clockwise until the leading edge of the incident pulse is five major divisions high (about 205 mr). 4. Position the waveform so that it is centered about the middle graticule line. ac –0.848 ft O N O F F Crosses Lowest Point O F F O F F Figure B–14: Cursor on Lowest Major Graticule that Rising Edge crosses n o POSITION control, and noting the distances displayed, verify 5.
Appendix B: Operator Performance Checks 8. Jitter Check Jitter is the uncertainty in the timebase. Its main effect is that the waveform appears to move back and forth a very small amount. If the jitter is too great, it will affect the repeatability of very precise distance measurements. 1. Set the VERT SCALE less than or equal to 1.0 mρ/div. 2. Watch the leading edge of the pulse move and verify that this movement is less than five pixels, or < 0.02 ft (0.006 m). ac –1.
Appendix B: Operator Performance Checks Conclusions If the instrument failed Jitter or Risetime checks, it is probably still adequate for all but extremely precise distance measurements. If it failed the Horizontal Scale check, you should not use the instrument until the cause of the failure has been identified and corrected. All of the previous checks only test the major functional blocks of the instrument that could prevent you from being able to make measurements.
Appendix C: Operator Troubleshooting For assistance in troubleshooting, use the following flow chart to determine if you have a simple problem you can fix or if the instrument needs to be sent to a Tektronix Service Center. Use this process to determine whether the instrument should be repaired or is OK to use when you have a problem.
Appendix C: Operator Troubleshooting Operator Troubleshooting (with cases on) Preset front panel and turn the power on. Is the power source a battery? YES NO Is there a greed display? YES Did “Initializing” message appear on LCD? YES NO NO Check line voltage switch for correct setting and change if necessary. With VOM, check wall outlet voltage and plug in somewhere else if no voltage. Check fuse and power cord for near zero Ohms. Using VOM, check for near zero Ohms in fuse.
Appendix C: Operator Troubleshooting Error Messages Any time the instrument displays an error message, the troubleshooting procedures should be used to judge the extent and severity of the problem. Some errors will still permit some kinds of measurements. If there is any doubt about the ability to make a particular kind of measurement, do not make that measurement until the problem has been corrected. Message: Option Port Device Not Responding... Please check for correct installation.
Appendix C: Operator Troubleshooting Occurrences: Meanings: At power on during initialization only. The instrument expects the pulse height to be slightly less than two major divisions high and adds gain to make the pulse exactly two divisions high. This message indicates that the pulse is non-existent, too small, or that the gain circuitry is not working correctly. If there is no pulse after pushing the MENU button, no measurements can be made. Have the instrument repaired.
Appendix C: Operator Troubleshooting Occurrences: At power on during initialization only. Meanings: The instrument changed the gain while adjusting the pulse to be two divisions high and the change in the gain circuitry did not make the expected change in the signal size. Remedies: Have the instrument repaired. If no other error messages occurred and the pulse is present, distance measurements can be made. Do not make loss measurements until the instrument has been repaired.
Appendix C: Operator Troubleshooting errors, which means that no measurements should be made with this instrument before it is repaired. C–6 Meanings: The instrument searches for a point on the leading edge of the pulse that is on the cable inside the instrument (about 10% up the pulse). This message indicates that the search failed. This could be because the pulse is not there, or because the sampler or gain circuitry is broken, or even because the timebase is not functioning properly.
Appendix D: Application Note Pulse Echo Testing of Electrical Transmission Lines Using the Tektronix Time-Domain Reflectometry Slide Rule Most people who make quantitative reflectometry tests or measurements should find the Tektronix TDR Slide Rule helpful. Those new to the subject will find the slide rule graphically summarizes a wealth of information on reflectometry. H Voltage Standing Wave Ratio vs. Percent Reflected Voltage H Return Loss, dB, vs.
Appendix D: Application Note Relationships ZO = (138 / pκ )* (log10 D / d) for coaxial cable % = r *100 VSWR = (1 + r) + (1 – r) for the case where VSWR is the same for all frequencies c = 30 cm / nanosecond = 0.984 ft / ns VF = 1 / pκ VP = 30 / pκ cm / ns = 0.984 / pκ ft /ns C = 7.36 κ + (log10 D / d) L = 140 log10 D / d 1 in = 2.54 cm 1 ft = 30.48 cm 1m = 3.28 ft VSWR vs.
Appendix D: Application Note NOTE. The relationship between % holds only when the loss is a single impedance discontinuity with negligible capacitive or inductive components (e.g., a 75 W termination at the end of a 50 W cable). The VSWR must be essentially the same for all sine-wave frequencies. Return Loss (dB) vs. Percent Reflected Voltage To find return loss in decibels, knowing the % (or vice versa), use the bottom scale of the Frequency Domain Conversions section of the slide rule (see Figure D–2).
Appendix D: Application Note Percent Reflected Voltage vs. Characteristic Line Impedance (50 or 75 ohm Source) To find the characteristic impedance of a line, or section of a line, knowing the reflection coefficient or the %, you should first know the impedance of the pulse generator. It should be as close as possible to the nominal impedance of the line and should be connected to the line through a length of cable having the same impedance as the source.
Appendix D: Application Note If the reflection is downward from the 50 W or 75 W reference level, set the reference level to the top of the chosen scale. If the reflection is toward a higher impedance than the reference level, set the reference level to the bottom of the chosen scale. Then count off the right number of divisions and subdivisions to locate the level corresponding to the peak of the reflection and read the corresponding impedance levels (Ohms) on the adjacent sliding scale.
Appendix D: Application Note Percent Reflected Voltage vs. Load Resistance To find the terminating load resistance (RL) of a line, knowing the percent reflected voltage or reflection coefficient, use the preceding instructions. If the load resistance is known, the previous procedures can be used to approximate the size of the return reflection. An error might be introduced if the impedance of the connecting cable does not match the source resistance of the pulse generator.
Appendix D: Application Note You should note that the peak level of any reflection that does not have a discernable plateau might be an erroneous indication of the impedance discontinuity that caused it. There might be several reasons for the error. 1) The discontinuity might occupy such a short segment of the line compared to the VP of the line and the risetime of the test pulse wavefront that part of the wavefront starts to emerge from the segment while the remainder is still entering.
Appendix D: Application Note Dielectric Constant vs. Velocity Factor Dielectric Constant and Velocity Factor appear on two identical scales next to a sliding scale labeled ROUND TRIP TIME. To find one, knowing the other, read across the sliding scale. Any major division on the sliding scale can be placed next to the known value to help read directly across the sliding scale. Time vs.
Appendix D: Application Note Time vs. Long Distances, in Meters or Feet (any dielectric) Distances to or between discontinuities farther apart than about three meters (10 feet) can be found on the METERS and FEET scale. Use the sliding ROUND TRIP TIME scale just below it and follow the same procedure as above. ONE–WAY DISTANCE TO OR BETWEEN FAULT, SPLICE, CONNECTOR, LOAD, END, OR OTHER IMPEDANCE DISCONTINUITY 20 30 40 50 60 70 80 100 METERS VELOCITY FACTOR 150ns 200ns 1.
Appendix D: Application Note D–10 1502C MTDR User Manual
Glossary Aberrations Imperfections or variations from a desired signal. In TDRs, a pulse of electrical energy is sent out over the cable. As the pulse-generating circuitry is turned on and off, the pulse is often distorted slightly and no longer is a perfect step or sine-shaped waveform. AC Alternating current is a method of delivering electrical energy by periodically changing the direction of the flow of electrons in the circuit or cable.
Glossary Characteristic Impedance Cables are designed to match the source and load for the electrical energy that they carry. The designed impedance is often called the characteristic impedance of the cable. The arrangement of the conductors with respect to each other is the major factor in designing the impedance of cables. Conductor Any substance that will readily allow electricity to flow through it. Good conductors are metals such as silver, copper, gold, aluminum, and zinc (in that order).
Glossary Impedance Mismatch A point in a cable or system where the incident electrical energy is redistributed into absorbed, reflected, and/or transmitted electrical energy. The transmitted electrical energy after the mismatch is less than the incident electrical energy. Incident Pulse The pulse of electrical energy sent out by the TDR. The waveform shown by the TDR consists of this pulse and the reflections of it coming back from the cable or circuit being tested.
Glossary means that each division is 0.5 rho (500 millirho). A pulse set to be four divisions high would make each division 0.25 rho (250 millirho). Noise Any unwanted electrical energy that interferes with a signal or measurement. Most noise is random with respect to the signals sent by the TDR to make a measurement and will appear on the waveform, constantly constantly moving up and down on the display.
Glossary Return Loss The amount of energy reflected or returned from a cable indicates how much the impedance in the system is mismatched. The ratio of the energy sent out by the TDR, divided by the energy reflected back, expressed in the logarithmic dB scale, is called return loss. Rho (r) (see Millirho) Risetime The time it takes a pulse signal to go from 10% to 90% of the change in voltage. RMS An acronym for Root Mean Squared.
Glossary denote changes resulting from environmental influences, such as temperature, humidity, vibration, and shock. TDR An acronym for Time-Domain Reflectometer. These instruments are also called cable radar. They send out pulses of energy and time the interval to reflections. If the velocity of the energy through the cable is known, distances to faults in the cable can be displayed or computed. Conversely, the speed that the energy travels through a cable of known length can also be computed.
Index A AC (see Power), xii Accessories, 3–2 Optional, 3–2 Standard, 3–2 accessories, standard, 3–2 Address, Tektronix, x Altitude Spec, A–3 B Battery (see Power), 1–2 Battery Pack Spec, A–2 BNC Connector, 3–2 C Cable Open, 1–15 Scrolling, 2–8 Short, 1–15, 2–19 Test Procedure, 1–14 Distance to Fault, 1–14 Horizontal Set Reference, 1–24 Reflection Coefficient, 1–17 Return Loss, 1–18 Store Waveform, 1–20 Vertical Set Reference, 1–26 View Difference, 1–21 View Input, 1–20 View Store, 1–21 Characteristics Ele
Index I Indicators, 1–6 Inspection, viii L List of Figures, iii List of Tables, vi Loss, 1–18 M Maintenance, C–1, D–1 Manual Changes, vii Max Hold (see Maximum Hold), 2–21 Maximum Hold, 1–29, 2–21 Menu, 1–8, 1–29, 2–1, 2–21 Cables, 1–8 Diagnostics, 1–9 Chart Recorder, 1–10 Head Alignment, 1-10 LCD Chart, 1-10 Front Panel, 1–10 LCD, 1–10 Alignment, 1-10 Contrast, 1-10 Drive Test, 1-10 Response Time, 1-10 Service, 1–9 Noise, 1-10 Offset / Gain, 1-10 RAM / ROM, 1-10 Sampling Efficiency, 1-9 Timebase, 1-10 D
Index Source, viii Voltage Rating, 1–2 Voltage Selector, 1–2 Voltages, 1–1 Product Description, vii Product support, contact information, x Pulse, 1–30, 2–1, 2–23 Incident, 2–3, 2–6, 2–13 Reflected, 2–3, 2–13 Q Physical, A–4 Store, 2–18 Store the Waveform, 1–20 T Table of Contents, i Tektronix, contacting, x Temperature, Low, 1–4 Terminator, 3–2 Troubleshooting, C–1, D–1 Tutorial, 2–1 Questions and Answers, 2–26 R References, vii Reflection Coefficient, 1–17 Repacking, viii Return Loss, 1–18 S Safety
Index Index–4 1502C MTDR User Manual
