Service Manual SD-22 & SD-26 Sampling Head 070-7227-02
Contents
1. 2 2 1 press un Internal Clock ENHANCED ACCURACY button 11801 2 press UTILITY button 11801A B CSA 803 Series press Enhanced Accuracy 11801A B CSA 803 Series touch Calibrate All pop up menu Recall Defaults Step 2 Touch Offset Null in the Enhanced Accuracy menu 0 Step 3 Touch Manual Calibrate in the Offset Nulling pop up menu 0 Step 4 Touch the Offset Null M1 selector 0 and then Enter in the Numeric Entry amp Knob Res pop up menu Step 5 Touch the vertical icon and then set Vert Size M1 to 50mV div Step 6 Press the MEASURE button 0 Step 7 Touch Measurements and then Mean in the Measurements pop up menu Step 8 Touch Mean in the MEASURE major menu and then set Data Interval to whole zone in the Mean pop up menu L L Step 9 Check that Mean is 0 V 200 mV L Step 10 Press the UTILITY button and t ouch Enhanced Accuracy 11801A B and CSA 803 Series or press the ENHANCED ACCURACY button 11801 2 0 Step 11 Touch Offset Null Step 12 Touch Automatic Calibrate and then Proceed in the Offset Nulling pop up menu 0 Step 13 Press the MEASURE button L Step 14 Examine that the Mean offset is 0 V 2 Step 15 Repeat Steps 2 through 14 for CH 2 Checks and Adjustments Setup to Check Offset Change with Repetition Rate 1 500 Termination 11801 Time Mark Generator mmm2. The specification for the dot transient response at 1 V is that the amplitude is adjustable to 100 Checks and Adjustments Checks and Adjustments Setup to Check Dot Transient Response 11801B CH 1 5X Attenuator Pulse Generator LLLLLL 2X Attenuator Internal Clock Output HL not connected yet CSA 803A Generator Trigger Output 2X Attenuator Internal Clock Output not connected yet Procedure to Check Dot Transient Response L Step 1 Initialize the instrument settings then make the following set tings in the order listed Sampling Head CH 1 SELECT CHANNEL On Instrument Mainframe Vert Size 1 50 mV division TRIGGER GUION serios pee ae tere ep press Internal Clock Main POS scort al da Main Size x9 EIS 20 ns division Pulse Generator Back Terminator button pull out Trigger Source External Trigger par DET square wave SD 22 amp SD 26 Service Manual 2 11 Checks and Adjustments Examine dot response at 250 mV with automatic calibration set tings by performing Steps 2 through 32 Step 2 Set the pulse generator s amplitude for a 375 mV display C Step 3 Set the Vert Offset MI so that the step is approximately cen tered on the screen 0 Step 4 Press
3. 3 4 Changing the Sampling Head Identification Number 3 6 Theory of Operation Theory of Operation 4 1 System Functional Overview 4 1 Loop Gain unse 4 2 ecran eT 4 3 Replaceable Parts Replaceable Parts 5 1 Parts Ordering Information 5 1 Using the Replaceable Parts 5 2 ii Contents SD 22 amp SD 26 Service Manual List of Figures Figure 1 1 Sampling Head Compartments in an 11801B and a p EE 1 4 Figure 1 2 Installing a Sampling Head in an Instrument 1 5 Figure 2 1 Locations of Controls and Connectors on Mainframe Instruments e Ts Rosen itecto dte DR e orsi 2 7 Figure 3 1 Sampling Head Screw Locations 3 5 Figure 3 2 A5 Time Base Controller Board Jumper Location 3 7 Figure 4 1 SD 22 and SD 26 Sampling Head Block Diagram 4 1 Figure 4 2 Displayed Traces at Various Loop Gain Settings 4 2 Figure 5 1 Exploded View of the SD 22 and SD 26 Sampling Heads q IP 5 5 iii List of Figures iv Contents SD 22 amp SD 26 Service Manual List of Tables Table 2 1 Measurement Limits and Specifications 2 1 Table 2 2 Test Equipment 2 3 Table 2 3 Aberration Specifications 2 26 Tab
4. L Step 22 Touch Loop Gain and then the channel you are using in the Loop Gain Calibration pop up menu Checks and Adjustments SD 22 amp SD 26 Service Manual 0 Step 23 Checks and Adjustments Setthe Divide by Two Mode to On in the Loop Gain Calibration pop up menu 0 Step 24 L Step 25 C Step 26 Touch Exit in the Loop Gain Calibration pop up menu Touch Cursors at the top of the screen Set Cursor 1 to the average of the bottom of the pulse before the step L Step 27 Set Cursor 2 to the average of the bottom of the pulse under the step C Step 28 0 Step 29 0 Step 30 0 Step 31 VLN L Step 32 Read AV and then record this value as VL for later use Set Cursor 2 to the average of the top of the pulse Read AV and then record this value as VH for later use Examine that the negative dot response error H x 10096 is 5 Examine that the positive dot response error 100 x VH V V VL is 596 Check dot tings by Step 33 response at 500 mV with automatic calibration set performing Steps 33 through 53 Press the UTILITY button and touch Enhanced Accuracy 11801A B and CSA 803 Series or press the ENHANCED ACCURACY button Step 34 L Step 35 pop up Step 36 C Step 37 0 Step 38 L Step 39 C Step 40 11801 2 Touch Loop Gain Set Divide by Two Mode to Off in the Loop Gain Calibration menu Touch Exit Set the
5. Oregon For more information on exchanging your sampling head refer to Module Exchange in Section 5 Replaceable Parts Maintenance Removing and Replacing the Sampling Head Internal Circuitry To avoid damage to the sampling head set the instrument ON STANDBY switch to STANDBY and remove the sampling head from the instrument before removing or replacing the internal circuitry Perform the following procedures to remove and replace the internal circuitry in the sampling head See Figure 3 1 O E a oe 0 Step 1 Remove the SELECT CHANNEL On Off button by gently pulling on the plastic knob with small needle nose pliers Step 2 Remove the three small Pozidrive screws on each side of the sampling head casing see Figure 3 1 Step 3 Remove the short circuit terminations the front panel and the casing from the internal circuitry Step 4 Install the internal circuitry into the gray shipping casing Step 5 Replace the short circuit terminations on the sampling head inputs Step 6 Return the internal circuitry the circuit board and attached carrier for sampling head exchange or repair Step 7 To replace the internal circuitry follow the removal procedures in reverse order Maintenance SD 22 amp SD 26 Service Manual Maintenance Left Side Short Circuit Terminations Right Side Short Circuit Terminations Figure 3 1 Sampling Head Screw Locations 3 5 Maintenance Ch
6. Press the STORE RECALL button 0 Step 15 Touch Trace 2 in the Store Trace pop up menu C Step 16 Touch Recall Trace in the STORE RECALL major menu C Step 17 Touch STO 1 in the Recall Stored Trace pop up menu SD 22 amp SD 26 Service Manual 2 31 Checks and Adjustments O Step 18 Disconnect the calibration step generator remote head from 2 connect it to CH 1 and then press the CH 1 SELECT CHANNEL On Off button Step 19 Press the MEASURE button Step 20 Touch Measurements and then Prop Delay in the Measure ments pop up menu Step 21 Touch Prop Delay in the MEASURE major menu and then Trace 3 in the Prop Delay pop up menu eg 00 Step 22 Check that the magnitude of the Prop Delay is x 10 ps 2 32 Checks and Adjustments Part 8 Maximum Signal Voltage Checks and Adjustments This part shows the setup and lists the procedure to examine the maximum signal voltage Measurement Limit The measurement limit for the maximum signal voltage is 196 of the step amplitude Setup to Examine Maximum Signal Voltage CH 1 11801B a 2 3 al a o gt Calibration e Generator Trigger Output le 44191 E Fast Rise Trigger Input 50 Q Coaxial Cable Positive Output CH 1 CSA 803A Calibration Generator Trigger Output E Fast Rise Trigger Input 50 Coaxial Cable Positive Output SD 22 amp SD 26 Service Manual 2 33 Checks and Adjustments Procedure to Ex
7. To avoid damage to the instrument set the instrument s ON STANDBY switch to STANDBY before installing or removing the sampling head The SD 22 amp SD 26 Sampling Head slide into the one of the front panel compartments of the 11800 Series Digital Sampling Oscilloscopes or CSA 803 Series Communications Signal Analyzers Figure 1 1 shows the front panel of an instrument and the locations of the sampling head compartments Sampling Head Compartments 11801B E m E a E L Sampling Head Compartments CSA 803A mmm Power Only Sampling Head Compartments Figure 1 1 Sampling Head Compartments in an 11801B and a CSA 803A General Information General Information With the ON STANDBY switch set to STANDBY place the sampling head in a compartment and slowly push it in with firm pressure Once the sampling head is seated turn the lock down screw to tighten the sampling head into place See Figure 1 2 To prevent damage to your instrument or sampling head never install or remove a sampling head when the ON STANDBY switch is ON If the green indicator light remains on when the STANDBY position is selected then the switch has been left internally disabled after the servicing of the power supply To enable the ON STANDBY switch refer to the Maintenance section of the Service Manual for your mainframe instrument To remove the sampling head from an instrument set the instrument s ON STANDBY switch to STAND
8. limits that indicate whether the sampling head is operating properly these limits are not to be interpreted as electrical specifications Initialized and Stored Settings At the beginning of most steps the user is instructed to Initialize the instru ment as part of the setup The Initialize feature available through the UTILITY menu presets all instrument controls and functions to known val ues Initializing the instrument at the beginning of a step eliminates the possibility of settings from previous parts causing erroneous or confusing results Menu Selections and Measurement Techniques Details on measurement techniques and instructions for making menu selections are generally not included in this manual Comprehensive de scriptions of menus and instrument mainframe features are located in the User Manual for your instrument and the SD 22 amp SD 26 Sampling Heads User Manual 2 5 Checks and Adjustments 2 6 Setup Illustrations You can use any 11800 Series Digital Sampling Oscilloscope or the CSA 803 Series Communications Signal Analyzer as the mainframe instrument in these procedures A Mainframe Instrument is shown in each procedure the exact location of connectors on your mainframe instrument may differ from that shown in the illustration In particular the 11802 Oscilloscope and CSA 803 Series Communications Signal Analyzer have only two sampling head acquisition compartments as compared to four in the 11801 Ser
9. Adjustments Checks and 2 1 Test Equipment 2 3 Using These Procedures 2 5 Conventions in this Manual 2 5 Initialized and Stored Settings 2 5 Menu Selections and Measurement Techniques 2 5 Setup Illustrations 2 6 Part 1 Power On 2 8 Part 2 Dot Transient Response 2 10 Part 3 Offsel 2 ne Dc werde EE 2 16 Part ANOIS 2 2542202 4 la ia 2 20 Part 5 Rise Time 5 25 8 Rx 2 23 Part 6 Acquisition Aberrations 2 26 Part 7 Coincidence Between Channels 2 30 Part 8 Maximum Signal Voltage 2 33 Part 9 Isolation Between Channels 2 36 Maintenance Maintenance ei 3 1 Preventive Maintenance 3 1 Periodic Electrical Checks 3 1 SD 22 amp SD 26 Service Manual i Table of Contents Static Sensitive Device Classification 3 1 Exchanging Sampling Heads 3 3 Removing and Replacing the Sampling Head Internal e ach ke PX bec
10. Allow three inches of packing on each side L Step 5 Seal the carton with shipping tape or with industrial staples L Step 6 Mark the address of the Tektronix service center and your return address on the carton in one or more prominent places General Information Operating Environment SD 22 amp SD 26 Service Manual General Information The following environmental requirements are provided to ensure proper operation and long sampling head life Operating Temperature Operate the sampling head where the ambient air temperature is between 0 C and 50 C Store the sampling head in ambient temperatures from 40 C to 75 C After storage at temperatures outside the operating limits allow the chassis to reach the operating temperature range before applying power Allow a 20 minute warmup before performing the calibrations in the Enhanced Accuracy menu of the instrument mainframe Calibrations should be repeated if the temperature changes more than 5 C or if the sampling head is removed from the instrument 1 7 General Information 1 8 General Information Checks and Adjustments Checks and Adjustments This section contains procedures to check the specifications and measure ment limits listed in Table 2 1 The Specification or Measurement Limit is listed at the beginning of each part as well These procedures contain only check steps since the SD 22 amp SD 26 Sampling Heads have no internal adjustmen
11. Effective Dscont Code No 067 1338 05 1 FIXTURE CAL SAMPLING HEAD CAL UNIT 80009 067133805 SWITZERLAND 067 1338 06 1 FIXTURE CAL SAMPLING HEAD CAL UNIT 80009 067133806 JAPANESE SS 5 Y lt o 0 2 s gt S p lt lt m 2 gt fi PP A Figure 5 1 Exploded View of the SD 22 amp SD 26 Sampling Heads SD 22 amp SD 26 Service Manual 5 5 Replaceable Parts 5 6 Replaceable Parts
12. POWER SWITCH set to OFF connect the instrument to a suitable power source L Step 4 Set the rear panel PRINCIPAL POWER SWITCH to ON and then the instrument s front panel ON STANDBY switch to ON When the instrument is first installed the rear panel PRINCIPAL POWER SWITCH should be set to and remain in the ON position Then use the front panel ON STANDBY switch to perform all subsequent power switching 2 8 Checks and Adjustments Checks and Adjustments L Step 5 Power on the following test equipment so that it is warmed up with the instrument to be tested m Calibration generator m Calibration step generator m Time mark generator m Pulse generator A complete list of test equipment is listed in Table 2 2 m Allow a 20 minute warm up for the sampling head and test equip ment before doing the performance checks SD 22 amp SD 26 Service Manual 2 9 Checks and Adjustments Part 2 Dot Transient Response This part shows the setup and lists the procedures to check the dot tran sient response The dot transient response is examined at 250 mV and 500 mV with automatic calibration settings at 500 mV with default settings and checked at 1 V with manual calibration settings Measurement Limits The measurement limits for the dot transient response error are m lt 5 error when measured at 250 mV and 500 mV with automatic calibration settings m 20 error when measured at 500 mV with default settings Specifications
13. and 500 ps before the 10 point of the step is lt 1 0 vertical divisions from the horizontal centerline 4 of the step amplitude 0 Step 31 Set the Main Size to 50 ps div and then the Main Pos so that the rising edge of the step is at the right most edge of the screen L Step 32 Examine that the magnitude of the maximum positive and negative aberrations that occur between 500 ps and 20 ps before the 10 point of the step is lt 1 0 vertical divisions from the horizontal centerline 4 of the step amplitude Step 33 Repeat Steps 2 through 32 for CH 2 SD 22 amp SD 26 Service Manual 2 29 Checks and Adjustments Part 7 Coincidence Between Channels 2 30 This part shows the setup and lists the procedures to check the coincidence between channels Specifications The specification for the coincidence between channels is 10 ps Setup to Check Coincidence Between Channels Calibration Step Generator Remote Head 11801B Calibration Step Generator Power Supply Calibration Step Generator Control Unit mem Power Trigger On Suppl Input upply o ww Standby Calibration Step Generator Remote Head Calibration Step CSA 803A Generator Power Supply Calibration Step Generator Control Unit mm Power Trigger On Supply Input elle efe e I D oT Checks and Adjustments Checks and Adjustments Procedure to Check Coincide
14. diagnostics are complete press the UTILITY button and then touch RS 232 Parameters Step 7 Setthe Baud Rate to 4800 Bd the Parity to none and the Stop Bits to 1 in the RS 232 Parameters pop up menu Step 8 Insert the Sampling Head Utility Software floppy disk provided in this manual into the drive of the system controller b Step 9 On the PC type a and then press the return or enter key Maintenance Maintenance J860 Figure 3 2 A5 Time Base Controller Board Jumper Location O Step 10 Type id and then press the return or enter key The PC then displays the following message Make sure 11800 RS232 port is set up as follows Baud Rate 4800 Parity none Stop bits 1 Enter mainframe head number 1 4 NOTE When entering the sampling head number the 11802 Oscilloscope and CSA 803 Series Communications Signal Analyzers only have head number 1 and head number 2 The 11801
15. step display Step 71 Press the UTILITY button and touch Enhanced Accuracy 11801A B and CSA 803 Series or press the ENHANCED ACCURACY button 11801 2 Step 72 Touch Loop Gain Step 73 Touch the channel number you are using in the Loop Gain Calibration pop up menu Step 74 Setthe Divide by Two Mode to On and then touch Manual Calibrate in the Loop Gain Calibration pop up menu Step 75 Touch Exit OO OO Step 76 Check that the amplitude of the pulse measured from the average of the level under the pulse to the average of the top of the pulse can be set with the manual calibration settings to be gt 1V O Step 77 Repeat Steps 2 through 76 for CH 2 SD 22 amp SD 26 Service Manual 2 15 Checks and Adjustments Part 3 Offset This part shows the setup and lists the procedure to examine offset and check offset with repetition rate Measurement Limits The measurement limit for the offset is 2 mV Specifications The specification for the offset change with repetition rate is 5 mV Setup to Examine Offset CH1 50 Termination 11801B CSA 803A Checks and Adjustments SD 22 amp SD 26 Service Manual Checks and Adjustments Procedure to Examine Offset L Step 1 Initialize the instrument settings then make the following set tings in the order listed Sampling Head CH 1 SELECT CHANNEL On Off On Instrument Mainframe TRIGGER
16. the UTILITY button and touch Enhanced Accuracy 11801A B and CSA 803 Series or press the ENHANCED ACCURACY button 11801 2 Step 5 Touch Loop Gain L Step 6 Touch Automatic Calibrate and then Proceed in the Loop Gain Calibration pop up menu Step 7 Touch Exit in the Loop Gain Calibration pop up menu Step 8 Set the pulse generator s amplitude for a 250 mV step display Step 9 Press the WAVEFORM button and then touch Horizontal Desc L Step 10 Touch Main Record Length in the Horizontal Description pop up menu and then set the top knob for a Main Record Length of 512 Step 11 Press the UTILITY button and then Instr Options L Step 12 Set Vectored Trace to Off in the Instrument Options pop up menu Step 13 Touch Display Intensity in the Instrument Options pop up menu and then set the top knob for 9096 intensity L Step 14 Touch Exit 0 Step 15 Touch Cursors on the top of the screen 0 Step 16 Touch Cursor Type and then Horizontal Bars in the Cursor Type pop up menu 0 Step 17 Touch Exit C Step 18 Set Cursor 1 top knob to the average of the bottom of the pulse before the step Step 19 Set Cursor 2 bottom knob to the top of the step L Step 20 Read AV as the peak to peak step amplitude and then record this value as V for later use Step 21 Press the UTILITY button and touch Enhanced Accuracy 11801A B and CSA 803 Series or press the ENHANCED ACCURACY button 11801 2
17. to accommodate improved components as they become available and to give you the benefit of the latest circuit improvements Therefore when ordering parts it is important to include the following information in your order m Part number m Instrument type or model number m Instrument serial number m Instrument modification number if applicable If a part you order has been replaced with a different or improved part your local Tektronix service center or representative will contact you concerning any change in the part number Change information if any is located at the rear of this manual Module Replacement The SD 22 amp SD 26 Sampling Heads are serviced by module replacement so there are three options you should consider Module Exchange In some cases you may exchange your module for a remanufactured module These modules cost significantly less than new modules and meet the same factory specifications For more infor mation about the module exchange program call 1 800 TEKWIDE ext 6630 Module Repair You may ship your module to us for repair after which we will return it to you New Modules You may purchase new replacement modules in the same way as other replacement parts 5 1 Replaceable Parts Using the The tabular information in the Replaceable Parts List is arranged for quick retrieval Understanding the structure and features of the list will help you Replaceable find the all the inf
18. 1 E a m m m 4 L not connected yet Je RE Gable CH 1 50 Termination CSA 803A mm 12 RF Cable not connected yet Checks and Adjustments 2 20 SD 22 amp SD 26 Service Manual Checks and Adjustments Procedure to Examine Noise L Step 1 Initialize the instrument settings then make the following set tings in the order listed Sampling Head CH 1 SELECT CHANNEL On Instrument Mainframe TRIGGER button 2 222 press GOUTE 225 455 x REP Rede Internal Clock ENHANCED ACCURACY button 11801 2 press UTILITY button 11801A B CSA 803 Series press Enhanced Accuracy 11801A B CSA 803 Series touch Calibrate All pop up menu Recall Defaults L Step 2 Touch Loop Gain in the Enhanced Accuracy menu Step 3 Disconnect the 50 termination from the 1 input and con nect the CALIBRATOR to the CH 1 input through the 12 inch RF cable L Step 4 Touch the channel number you are using Automatic Calibrate and then Proceed in the Loop Gain Calibration pop up menu 0 Step 5 Disconnect the CALIBRATOR from the CH 1 input and recon nect the 50 termination Step 6 Press the WAVEFORM button and then touch Acquire Desc Step 7 Set Average N to On Step 8 Press the AUTOSET button O Step 9 Touch the vertical 1 icon Set the Vert Size M1 to 2 mV div 0 S
19. 1 TURNBULL CT 06611 4739 Replaceable Parts Fig amp Tektronix Serial No Qty amp Description Mfr Mfr Part No Index Part No Effective Dscont Code No 5 1 1 366 0673 00 2 KNOB O 096 ID X 0 24 OD X 0 299H TK1163 ORDER BY DESC 2 334 7624 00 1 LABEL FRONT PANEL SD22 0 05 ORDER BY DESC 334 7363 00 1 LABEL MARKED SD26 PANEL FRONT OKBO5 ORDER BY DESC 334 7638 00 2 MARKER IDENT MKD STATIC WARNING 0 05 ORDER BY DESC 3 211 0088 00 3 SCREW MACHINE 2 56 X 0 281 FLH 82 DEG STL TK0435 ORDER BY DESC 4 333 3427 01 1 PANEL FRONT 80009 ORDER BY DESC 5 380 0831 00 1 HSG SMPLG HEAD ALUMINUM TK1465 ORDER BY DESC 6 211 0087 01 3 SCREW MACHINE 2 56 X 0 188 FLH 82 DEG STL TK0435 ORDER BY DESC 657 0069 50 1 MODULAR ASSY FIELD REPLACEABLE UNIT SD22 80009 657006950 657 0065 50 010100 B020439 1 MODULAR KIT SD26 EXCHANGE MODULAR ASSY 80009 657006550 657 0065 51 020440 1 MODULAR ASSY SD26 FIELD REPLACEABLE UNIT 80009 657006551 STANDARD ACCESSORIES 015 1020 00 2 TERM COAXIAL SHORT CIRCUIT SMA 0GZV8 645 50 0 1 070 7226 02 1 MANUAL TECH USER SD22 SD26 80009 070722602 070 7227 02 1 MANUAL TECH SERVICE SD22 SD26 80009 070722702 OPTIONAL ACCESSORIES 011 0148 00 1 50 0 1 OHM PRECISION 3 5MM 20944 28K50 011 0149 00 1 50 OHM 26 5GHZ PRECISION 3 5MM 20944 28 50 011 0150 00 1 TERM COAX SHORT 34GHZ PRECISION 3 5MM 13047 360D 011 0151 00 1 TERM COAX SHORTING 34 G
20. 12 Touch Measurements and then Mean in the Measurements pop up menu Step 13 Touch Compare amp References in the MEASURE major menu Step 14 Touch Save Current Meas Values as References and then set Compare to On L Step 15 Setthe time mark generator s marker setting to 5 ms L Step 16 Wait until the Acquire Desc selector in the WAVEFORM major menu shows that eight averages have been completed 0 Step 17 Check that AMean offset with a repetition rate is 0 V 5 mV Step 18 Continue to decrease the time mark generator s marker set ting and repeat Step 17 for each setting down to 0 1 us Step 19 Press the CH 2 SELECT CHANNEL button L Step 20 Disconnect the 50 termination from the CH 1 input and connect it to the CH 2 input 0 Step 21 Repeat Steps 4 through 18 for CH 2 SD 22 amp SD 26 Service Manual 2 19 Checks and Adjustments Part 4 Noise This part shows the setup and lists the procedures to check noise from the sampling head Measurement Limits SD 22 The measurement limits for noise is 800 without smoothing and 400 uVnys with smoothing Measurement Limits SD 26 SN B020440 and above The measurement limit for noise is 1 2 mVams without smoothing and 550 uVpms with smoothing Measurement Limits SD 26 SN B010339 and below The measurement limit for noise is 2 0 mVgys without smoothing and 900 HVnws with smoothing Setup to Examine Noise 1 500 Termination 1180
21. 128 with the top knob L Step 9 Touch the vertical 1 icon and then set the Vert Offset M1 so that the average of the top of the pulse 500 ns after the step is on the horizontal centerline Step 10 Set Vert Size M1 to 5 mV div Step 11 Touch Vert Offset M1 and then Fine in the Numeric Entry amp Knob Res pop up menu Step 12 Set Vert Offset M1 so that the average of the top of the pulse 500 ns after the step is on the horizontal centerline DO Step 13 Set the Main Size to 200 ns div 2 34 Checks and Adjustments Checks and Adjustments L Step 14 Examine that the magnitude of the maximum positive and negative aberrations that occur between 200 ns and 800 ns from the rising edge of the step is lt 2 vertical divisions from the horizontal center line 196 of the step amplitude Step 15 Touch the horizontal icon and then set the Main Size to 20 ns div 0 Step 16 Set the Main Pos so that the step is within 1 2 division of the left most edge of the screen L Step 17 Examine that the magnitude of the maximum positive and negative aberrations between 10 ns and 200 ns from the rising edge of the step is lt 2 vertical divisions from the horizontal centerline 196 of the step amplitude Step 18 Repeat all of Part 8 for CH 2 SD 22 amp SD 26 Service Manual 2 35 Checks and Adjustments Part 9 Isolation Between Channels 2 36 This part shows the setup and lists the procedures to chec
22. 50 Q Coaxial Cable 50 Q Termination CH 1 50 Q Termination CSA 803A Generator 50 Q Coaxial Cable 500 Termination Procedure to Check Offset Change with Repetition Rate L Step 1 Initialize the instrument settings then make the following set tings in the order listed Sampling Head CH 1 SELECT CHANNEL On Instrument Mainframe ENHANCED ACCURACY button 11801 2 press UTILITY button 11801A B CSA 803 Series press Enhanced Accuracy 11801A B CSA 803 Series touch Calibrate All pop up menu Recall Defaults Time Mark Generator Marker Sec uscire ee xx dace dy CREE Pei 0 2 us 0 Step 2 Press the TRIGGER button and then touch Level L Step 3 Adjust the Trig Level until a trace appears 2 18 Checks and Adjustments Checks and Adjustments Step 4 Touch the vertical icon and then set the Vert Size M1 to 2 mV div Step 5 Set Vert Offset M1 so that the trace is vertically centered on the screen L Step 6 Set the time mark generator s marker setting to 10 ms 0 Step 7 Press the WAVEFORM button and then touch Acquire Desc Step 8 Set Average to and then touch Set Avg 0 Step 9 Set Average N to 8 with the top knob L Step 10 Wait until the Acquire Desc selector in the WAVEFORM major menu shows that eight averages have been completed Step 11 Press the MEASURE button Step
23. BY Turn the lock down screw and then slowly pull out the sampling head Mainframe Sampling Head Figure 1 2 Installing a Sampling Head in an Instrument SD 22 amp SD 26 Service Manual 1 5 General Information Packaging for Shipment If possible save and reuse the original carton and packaging to the pack age sampling head when shipping it by commercial transportation Attach a tag to the sampling head if it is shipped to your local Tektronix service center for service or repair Include the following information on the tag m Name and address of the instrument and sampling head owner m Name ofa person at your firm who can be contacted about the instru ment and sampling head m Complete instrument and sampling head type and serial number m A description of the service required Package the sampling head as follows if the original package is not avail able or is not fit for use L Step 1 Attach short circuit terminations to the sampling head inputs 0 Step 2 Obtain a corrugated cardboard carton with inside dimensions at least six inches 15 cm greater than the sampling head dimensions Use a carton with a bursting test strength of at least 200 pounds per square inch L Step 3 Fully wrap the sampling head with antistatic sheeting or its equivalent to protect the finish Step 4 Tightly pack dunnage or urethane foam between the carton and the sampling head to cushion the sampling head on all sides
24. HZ 3 5MM MALE 13047 360B 011 0152 00 1 50 OHM 6DB 40 0 GHZ 2 92MM 20944 41KC 6 011 0153 00 1 50 OHM 20DB 2 92MM 20944 41 20 015 0549 00 1 CONN RF ADPT SMA 50 OHM MALE FEMALE 0GZV8 335 50 0 1 015 0550 00 1 ADPTR RF PRCN 3 5MM FEMALE TO FEMALE 20944 335 5 50 015 0551 00 1 ADPTR RF PRCN 3 5MM MALE MALE 20944 335550 015 0552 00 1 ADPTR APC ELEC 3 5MM MALE TO FEMALE 02660 131 7053 015 0553 00 1 ADPTR SMA ELEC MALE FEMALE 98291 50 674 6324 99 015 0557 00 1 POWER DIVIDER DC 40 GHZ 2 92MM FEMALE 20944 K240C 015 0558 00 1 TERMINATOR ELEC 10 X 20DB DC 10 GHZ 66598 523 150 015 0561 00 1 CABLE DLY COAX 50 OHM 4NS W CONN MALE 0GZV8 SF104PE 920MM 2 015 0562 00 1 CABLE DLY COAX 50 OHM 1NS W CONN MALE 0GZV8 SF104PE 230MM 2 015 0563 00 1 CABLE DLY COAX 50 OHM 2NS W CONN 0GZV8 SF104PE 460MM 2 015 0564 00 1 CABLE DLY COAX 50 OHM 500PS W CONN 20944 120 6 020 1693 00 1 COMPONENT KIT SMA KIT 80009 020169300 067 1338 00 1 FIXTURE CAL SAMPLING HEAD CAL UNIT 80009 067133800 STANDARD 067 1338 01 1 FIXTURE CAL SAMPLING HEAD CAL UNIT 80009 067133801 EUROPEAN 067 1338 02 1 FIXTURE CAL SAMPLING HEAD CAL UNIT 80009 067133802 UNITED KINGDOM 067 1338 03 1 FIXTURE CAL SAMPLING HEAD CAL UNIT 80009 067133803 AUSTRALIAN 5 4 Replaceable Parts Replaceable Parts Fig amp Tektronix Serial No Qty Name amp Description Mfr Mfr Part No Index Part No
25. M1 to 2 mV div Step 10 Touch Vert Offset M1 and then Fine in the Numeric Entry amp Knob Res pop up menu Step 11 Set Vert Offset M1 so that the average of the top of the pulse between 100 ns after the step and the right edge of the screen is at the horizontal centerline Step 12 Examine that the magnitude of the maximum positive and negative aberrations that occur 100 ns after the step is lt 0 75 vertical divisions from the horizontal centerline 0 696 of the step amplitude Step 13 Touch the horizontal lt gt icon and then set the Main Size to 10 ns div Step 14 Set the Main Pos so that the rising edge of the step is at the left most edge of the screen Step 15 Examine that the magnitude of the maximum positive and negative aberrations that occur between 5 ns and 100 ns after the step is lt 1 5 vertical divisions from the horizontal centerline 1 296 of the step amplitude Step 16 Set the Main Size to 500 ps div and then the Main Pos so that the rising edge of the step is at the left most edge of the screen Step 17 Examine that the magnitude of the maximum positive and negative aberrations that occur between 300 ps and 5 ns after the step is 5 0 vertical divisions from the horizontal centerline 4 0 of the step amplitude Step 18 Touch the horizontal icon and then set the Main Size to 500 ns div Step 19 Touch the vertical icon and then set the Vert Size M1 to 10 mV div Checks and Ad
26. Series Oscillo scopes have head number 1 through head number 4 The head numbers correspond to the sampling head compartments and are in ascending order reading from left to right SD 22 amp SD 26 Service Manual 3 7 Maintenance L Step 11 To Enter the sampling head number type in the correct sam pling head number and then press the return or enter key The PC then displays the following message Current ID number is Enter new ID number 8 characters max NOTE The X s between the quotes represent the current ID number Eight is the maximum number of digits allowed and one is the minimum Any character is allowed except a space character L Step 12 Enter between one and eight characters for the new identifica tion number The instrument will then flash the message Change in channel M x configuration four times at the top of the screen 0 Step 13 Set the ON STANDBY switch to STANDBY and then switch it back to ON L Step 14 To verify the new identification number press the UTILITY button and then touch Identify The new identification number now appears under Mainframe Sampling Heads in the System Identification pop up menu O Step 15 Remove the short circuit jumper that was installed on J860 in Step 1 Maintenance Theory of Operation Theory of Operation The SD 22 Sampling Head is a two channel low noise 28 ps rise time sampling head The SD 26 Sampling Head is a tw
27. Service Manual Tektronix Y SD 22 amp SD 26 Sampling Head 070 7227 02 Warning The servicing instructions are for use by qualified personnel only To avoid personal injury do not perform any servicing unless you are qualified to do so Refer to the Safety Summary prior to per forming service Please check for change information at the rear of this manual First Printing May 1993 www tektronix com Instrument Serial Numbers Each instrument manufactured by Tektronix has a serial number on a panel insert or tag or stamped on the chassis The first letter in the serial number designates the country of manufacture The last five digits of the serial number are assigned sequentially and are unique to each instrument Those manufactured in the United States have six unique digits The country of manufacture is identified as follows B010000 Tektronix Inc Beaverton Oregon USA E200000 Tektronix United Kingdom Ltd London J300000 Sony Tektronix Japan H700000 Tektronix Holland NV Heerenveen The Netherlands Instruments manufactured for Tektronix by external vendors outside the United States are assigned a two digit alpha code to identify the country of manufacture e g JP for Japan HK for Hong Kong IL for Israel etc Tektronix Inc PO Box 500 Beaverton OR 97077 Printed in U S A Copyright Tektronix Inc 1989 1993 All rights reserved Tektronix products are covered by U S and foreign patents iss
28. Supply Input on ele ole e J 0 ee e EN Standby Procedure to Examine Acquisition Aberrations O Step 1 Initialize the instrument settings then make the following set tings in the order listed Sampling Head CH1 SELECT CHANNEL On Off On Instrument Mainframe ENHANCED ACCURACY button 11801 2 press UTILITY button 11801A B CSA 803 Series press Enhanced Accuracy 11801A B CSA 803 Series touch Calibrate All pop up menu Recall Defaults TRIGGER GUION 552525 ERG ERR press SOUFCE fic ikea eine Internal Clock Calibration Step Generator ON STANDBY switch ON SD 22 amp SD 26 Service Manual 2 27 Checks and Adjustments 2 28 O O O O O O O O O Step 2 Press the WAVEFORM button and then touch Acquire Desc Step 3 Set Average N to On and then touch Set Avg N Step 4 Set Average N to 128 with the top knob Step 5 Press the AUTOSET button Step 6 Touch the horizontal icon and then set the Main Size to 100 ns div Step 7 Setthe Main Pos so that the rising edge of the step is at the left most edge of the screen Step 8 Touch the vertical 1 icon and then set the Vert Offset M1 so that the average of the top of the pulse between 100 ns after the step and the right edge of the screen is at the horizontal centerline Step 9 Set the Vert Size
29. Vert Size M1 to 100 mV div Set the pulse generator s amplitude for a 500 mV step display Touch Cursors on the top of the screen Set Cursor 1 to the average of the bottom of the pulse before the step Step 41 Step 42 Set Cursor 2 to the average of the top of the pulse Read AV as the peak to peak step amplitude and then record this value as V for later use 0 Step 43 Press the UTILITY button and touch Enhanced Accuracy 11801A B and CSA 803 Series or press the ENHANCED ACCURACY button 11801 2 Checks and Adjustments Step 44 Touch Loop Gain and then the channel number you are using in the Loop Gain Calibration pop up menu 0 Step 45 Set Divide by Two Mode to On in the Loop Gain Calibration pop up menu 0 Step 46 Touch Cursors at the top of the screen L Step 47 Set Cursor 1 to the average of the bottom of the pulse before the step Step 48 Set Cursor 2 to the average of the bottom of the pulse after the step Step 49 Read the AV value and then record this value as VL for later use 0 Step 50 Set Cursor 2 to the average of the top of the pulse Step 51 Read and then record this value as VH for later use L Step 52 Examine that the negative dot response error VL VH x 100 is x 596 L Step 53 Examine that the positive dot response error 100 x VH V V VL is x 5 Check dot response at 500 mV with default settings by perform ing Steps 54
30. amine Maximum Signal Voltage L Step 1 Initialize the instrument settings then make the following set tings in the order listed Sampling Head CH 1 SELECT CHANNEL On Instrument Mainframe ENHANCED ACCURACY button 11801 2 press UTILITY button 11801A B CSA 803 Series press Enhanced Accuracy 11801A B CSA 803 Series touch Calibrate All pop up menu Recall Defaults TRIGGER 22 2222 22 press 5 m 5 us div Calibration Generator maximum amplitude Period ren ann ee eS 10 us Variable adjustment mid range L Step 2 Touch the vertical 1 icon and then set the Vert Offset M1 so that the waveform is vertically centered on the screen 0 Step 3 Set the calibration generator s amplitude so that it displays a 1 V peak to peak square wave 0 Step 4 Touch the horizontal lt gt icon and then set the Main Size to 500 ns div Step 5 Setthe Main Pos so that the positive going step is within 1 2 division to the right of the left most edge of the screen 0 Step 6 Press the WAVEFORM button L Step 7 Touch Acquire Desc and then set Average N to On in the Acquire Description pop up menu C Step 8 Touch Set Avg N and then set Average N to
31. anging the Sampling Head Identification Number The following procedure allows you to change the sampling head identifica tion number to fit the requirements of your application The following equipment in addition to 11800 Series or CSA 803 Series instrument and the sampling head is necessary to perform this procedure m IBM PC or any other compatible PC that has MS DOS and an RS 232 C serial port configured for COM1 m aserial cable Procedure to change the sampling head identification number Step 1 Set the instrument s PRINCIPAL POWER SWITCH to OFF Install one of the short circuit jumpers across the two J860 pins on the A5 Time Base Controller Board These short circuit jumpers are located on several jumper pins on the A5 Time Base Controller Board This board is located on the bottom of the instrument and can be accessed once the bottom panel is removed Refer to the Maintenance section in the Service Manual for your instrument for more information on accessing this board See Figure 3 2 for the location of jumper J860 0 Step 2 Boot up the PC with MS DOS operating Step 3 Connect the serial cable to the instrument s RS 232 C port located at the rear of the instrument Connect the other end of the cable to the COM1 port on the O Step 4 Install the sampling head in any sampling head compartment in the instrument Step 5 Setthe PRINCIPAL POWER SWITCH to ON and the ON STANDBY switch to ON Step 6 After the
32. bration Step Generator rise NOTE Calibration Step Generation rise is read from the calibration step generator Step 23 Check that the SD 22 Sampling Head rise time is 28 ps or that the SD 26 Sampling Head rise time is lt 17 5 ps 0 Step 24 Repeat Steps 2 through 23 for CH 2 SD 22 amp SD 26 Service Manual 2 25 Checks and Adjustments Part 6 Acquisition Aberrations 2 26 This part shows the setup and lists the procedure to check acquisition aberrations Measurement Limits The measurement limits for acquisition aberrations are listed in Table 2 3 Aberration Specifications Table 2 3 Aberration Specifications Time Difference from the Minimum Specification Rising Edge of Waveform 0 to 300 ps 7 x aberration lt 12 300 ps to 5 ns 496 x aberration 96 x 496 5 ns to 100 ns 1 296 lt aberration 1 296 100 ns and up 0 6 x aberration 96 x 0 696 10 ns to 20 ps 496 x aberration x 496 Checks and Adjustments Checks and Adjustments Setup to Examine Acquisition Aberrations Calibration Step Generator Remote Head 11801B Calibration Step Generator Power Supply Calibration Step Generator Control Unit Power Trigger On Input Standby Calibration Step Generator CSA 803A Remote Head Calibration Step Generator all ca 22 Power Supply a 3 gt Calibration Step e 4 Generator da Control Unit Power Trigger zu n ure
33. d wrist strap Step 4 Clear the work station surface of anything that can generate or hold a static charge Step 5 Keep the component leads shorted together whenever possible O O O Step 6 Pick up components by the body never by the leads O Step 7 Do not slide the components over any surface O Step 8 Avoid handling components in areas that have a floor or work surface covering capable of generating a static charge Table 3 1 Relative Susceptibility to Electrostatic Discharge ESD Semiconductor Classes Relative Susceptibility Levels MOS or CMOS microcircuits or discrete circuits or 1 linear microcircuits with MOS inputs most sensitive ECL 2 Schottky signal diodes 3 Schottky TTL 4 High frequency bipolar transistors 5 JFET 6 Linear microcircuits 7 Low power Schottky TTL 8 TTL least sensitive 9 1Voltage equivalent for levels voltage discharged from a 100 pF capacitor through resis tance of 100 Q 1 100 to 500 V 6 600 to 800 V 2 200 to 500 V 7 400 to 1000 V est 3 250 8 900 4 500 9 1200 V 5 400 to 600 V Maintenance SD 22 amp SD 26 Service Manual Maintenance Exchanging Sampling Heads If a sampling head fails any of the procedures in Section 2 Checks and Adjustments then it can be exchanged for a new sampling head Sampling head exchanges can be made with either your local Tektronix service center or the Central Tektronix Exchange Center in Beaverton
34. d rise time is 28 ps The speci fication for the SD 26 Sampling Head rise time is 17 5 ps Setup to Check Rise Time Calibration Step Generator Remote Head 11801B Calibration Step Generator 3 Power Supply Er Calibration Step Generator L Control Unit Power Trigger upply Input vr Standby Calibration Step Generator CSA 803A Remote Head Calibration Step Generator All Ca aa ED Power 3 Supply a x B Calibration Step e 4 Generator C3 e Control Unit Power Trigger Supply Input on ele ele o J 9 9 elle EN standby SD 22 amp SD 26 Service Manual 2 23 Checks and Adjustments Procedure to Check Rise Time L Step 1 Initialize the instrument settings then make the following set tings in the order listed Sampling Head CH 1 SELECT CHANNEL On Instrument Mainframe ENHANCED ACCURACY button 11801 2 press UTILITY button 11801A B CSA 803 Series press Enhanced Accuracy 11801A B CSA 803 Series touch Calibrate All pop up menu Recall Defaults TRIGGER button press chup PER Internal Clock Calibration step generator ON STANDBY switch ON C Step 2 Press the AUTOSET button Step 3 Press the WAVEFORM button and then touch Horizontal Desc Step 4 Touch Main Record Length and then set Main Reco
35. e Nose Pliers Pozidrive Screwdriver 6 dB attenuation 50 Tektronix Part 011 0069 02 one male and one female BNC 14 dB attenuation 50 Tektronix Part 011 0060 02 one male and one female BNC Tektronix Part 006 3415 01 Tektronix Part 006 3414 00 P1 tip Checks and Adjustments Using These Procedures SD 22 amp SD 26 Service Manual Checks and Adjustments Each part begins with a setup illustration that shows the test equipment and how to connect it Refer to Table 2 2 for an example of the test equipment for each part Conventions in this Manual In these procedures the following conventions are used m CAPITAL letters within the body of text identify front panel controls indicators and connectors for example MEASURE on the oscilloscope and sampling head m Bold letters identify menu labels and display messages m Initial Capital letters identify connectors controls and indicators for example Position on associated test equipment Initial Capital letters also identify adjustments inside the sampling head In some steps the first word is italicized to identify a step that contains a performance verification and or an adjustment instruction For example if Check is the first word in the title of a step an electrical specification is checked If Adjust appears in the title the step involves an electrical adjust ment If Examine is the first word in the title the step concerns measurement
36. epair or service the product b to repair damage resulting from improper use or connection to incompatible equipment or c to service a product that has been modified or integrated with other products when the effect of such modification or integration increases the time or difficulty of servicing the product THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THIS PRODUCT IN LIEU OF ANY OTHER WARRANTIES EXPRESSED OR IMPLIED TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE TEKTRONIX RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND EXCLUSIVE REMEDY PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES Table of Contents List Of FIQUICS ea an aite ean a o iii List of Tables ai General Information General Information 1 1 Introduction sur RR ea 1 1 Safety Summary 1 2 Installing and Removing the Sampling Head 1 4 Packaging for Shipment 1 6 Operating 1 7 Operating Temperature 1 7 Checks and
37. erty WARNING statements in manuals identify conditions or practices that could result in personal injury or loss of life Terms on Equipment CAUTION on equipment means a personal injury hazard not immediately accessible as one reads the marking or a hazard to property including the equipment itself DANGER on equipment means a personal injury hazard immediately acces sible as one reads the marking Symbols in Manuals 9 Static Sensitive Devices Symbols on Equipment 4 DANGER Protective ATTENTION High Voltage ground earth Refer to terminal manual Grounding the Instrument The sampling head is grounded through the grounding conductor of the oscilloscope s power cord To avoid electric shock plug the power cord into a properly wired receptacle before connecting to the product input or output terminal A protective ground connection by way of the grounding conduc tor in the power cord is essential for safe operation Danger Arising from Loss of Ground Upon loss of the protective ground connection all accessible conductive parts including knobs and controls that may appear to be insulating can render an electric shock General Information SD 22 amp SD 26 Service Manual General Information Do Not Operate in Explosive Atmospheres To avoid explosion do not operate the sampling head in an atmosphere of explosive gasses 1 3 General Information Installing and Removing the Sampling Head
38. ge change will be between the value of the last sample and the new voltage If loop gain is adjusted too high then the value of the first sample acquired after the input voltage change will be greater than the new voltage level Figure 4 2 shows the displayed trace results for the three loop gain conditions Unity Loop Gain Insufficient Loop Gain Excessive Loop Gain Figure 4 2 Displayed Traces at Various Loop Gain Settings Theory of Operation Offset Null SD 22 amp SD 26 Service Manual Theory of Operation The offset null adjustment removes unwanted DC offset that may be present in the sampling head This adjustment effectively zeroes the sampling head so that an input signal with 0 V of amplitude delivers a 0 V output If offset null is not adjusted correctly then measurements taken at the instru ment will be incorrect The absolute voltage values for any cursors displayed on the trace will be incorrect as well 4 3 Theory of Operation 4 4 Theory of Operation Replaceable Parts Parts Ordering Information SD 22 amp SD 26 Service Manual Replaceable Parts This section contains a list of the components that are replaceable for the SD 22 amp SD 26 Sampling Heads As described below use this list to identify and order replacement parts Replacement parts are available from or through your local Tektronix Inc service center or representative Changes to Tektronix instruments are sometimes made
39. he 50 O termination to CH 1 and then press the CH 2 SELECT CHANNEL On Off button Step 21 Press the AUTOSET button 0 Step 22 Touch the horizontal icon and then set the Main Size to 200 ps div Step 23 Press the CH 1 SELECT CHANNEL button 0 Step 24 Press the AUTOSET button Step 25 Press the WAVEFORM button L Step 26 Wait until the Acquire Desc selector in the WAVEFORM major menu shows that 1024 averages have been completed Step 27 Press the MEASURE button 0 Step 28 Record the CH 1 Peak Peak measurement for later use 0 Step 29 Press the 2 SELECT CHANNEL button 0 Step 30 Record the CH 2 Peak Peak measurement for later use Step 31 Check that CH 1 Peak Peak CH 2 Peak Peak x 100 lt 196 2 38 Checks and Adjustments Maintenance Preventive Maintenance SD 22 amp SD 26 Service Manual Maintenance This section contains information for performing preventive maintenance and procedures for exchanging faulty sampling heads removing and replacing sampling head internal circuitry and changing the sampling head identifica tion number Preventive maintenance performed regularly can prevent breakdown and may improve reliability of the instrument or sampling head The severity of the environment to which the sampling head is subjected determines the frequency of maintenance Periodic Electrical Checks To ensure accurate measurements perform periodic electrical checks on the in
40. ies Oscilloscopes Locations of controls and connectors on each instrument are shown in Figure 2 1 Checks and Adjustments Checks and Adjustments 11801 mm DU Sl Calibrator Output Left Sampling Head Compartment n LLLLLL Trigger Input Internal Clock Output Left Sampling Head E Sn Calibrator Output 11802 Trigger Input Internal Clock Output 11801A and CIL TH Tni UUU Output Antistatic Connection Trigger Input Internal Clock Output al Left Sampling Head Compartment CSA 803 and CSA STA aa Left Sampling Head Compartment Leite ee e3 1 Calibrator Output Antistatic Connection Trigger Inputs Internal Clock Output Figure 2 1 Locations of Controls and Connectors on Mainframe Instruments SD 22 amp SD 26 Service Manual 2 7 Checks and Adjustments Part 1 Perform this part within the ambient temperature range of 18 C to Power On en Setup to Power on 11801B Sampling 3 Head o L installed yet CSA 803A E za Sampling E Head C3 o e not installed yet Procedure to Power On 0 Step 1 Set the following in the order listed Sampling Head Not installed yet Instrument Mainframe ON STANDBY switch STANDBY Step 2 Install the SD 22 or SD 26 sampling head in the left plug in compartment 0 Step 3 With the instrument s rear panel PRINCIPAL
41. justments Checks and Adjustments 0 Step 20 Set the Vert Offset M1 so that the average of the top of the pulse between 100 ns after the step and the right edge of the screen is at the horizontal centerline C Step 21 Touch the horizontal icon and then set the Main Size to 50 ps Step 22 Set the Main Pos so that the rising edge of the step is at the left most edge of the screen L Step 23 Examine that the magnitude of the maximum positive aberra tion that occurs in the first 300 ps after the step is lt 3 0 vertical divisions from the horizontal centerline 1296 of the step amplitude 0 Step 24 Examine that the magnitude of the maximum negative aberra tion that occurs in the first 300 ps after the step is lt 1 75 vertical divi sions from the horizontal centerline 796 of the step amplitude Step 25 Touch the Main Pos selector and then Set to Min in the Numeric Entry and Knob Res pop up menu Step 26 Set the Main Size to 10 ns div L Step 27 Touch the vertical icon and then set Vert Offset M1 so that the average of the bottom of the pulse 10 ns before the step is at the horizontal centerline L Step 28 Touch the horizontal icon and then set the Main Size to 1 ns div L Step 29 Set the Main Pos so that the rising edge of the step is at the right most edge of the screen L Step 30 Examine that the magnitude of the maximum positive and negative aberrations that occur between 10 ns
42. k the isolation between channels Specifications The measurement limit for the isolation between channels is 196 Setup to Check Isolation Between Channels Calibration Step Generator Remote Head Calibration Step Generator Power Supply 11801B Calibration Step Generator Control Unit RE Power Trigger On Suppl Input upply o ww Standby 50 Termination Calibration Step Generator Remote Head Calibration Step CSA 803A Generator Power Supply Calibration Step Generator Control Unit mm Power Trigger On o Standby 50 Q Termination Checks and Adjustments SD 22 amp SD 26 Service Manual Checks and Adjustments Procedure to Check Isolation Between Channels L Step 1 Initialize the instrument settings then make the following set tings in the order listed Sampling Head CH 1 SELECT CHANNEL On Instrument Mainframe ENHANCED ACCURACY button 11801 2 press UTILITY button 11801A B CSA 803 Series press Enhanced Accuracy 11801A B CSA 803 Series touch Calibrate All pop up menu Recall Defaults TRIGGER button 2 22 press chip PER Internal Clock Calibration Step Generator ON STANDBY ON Step 2 Press the AUTOSET button L Step 3 Touch the h
43. le 3 1 Relative Susceptibility to Electrostatic Discharge ESD 3 2 List of Tables vi Contents General Information Introduction General Information This section gives all the information needed to apply power to the SD 22 amp SD 26 Sampling Heads Safety information as well as information on installing and removing the sampling head packaging for shipment and environmental conditions such as operating temperature is included here The SD 22 amp SD 26 Sampling Head Service Manual is designed for use by qualified service personnel It contains information necessary to check and maintain the SD 22 amp SD 26 Sampling Heads The SD 22 Sampling Head is a two channel low noise 28 ps rise time sampling head The SD 26 Sampling Head is a two channel 17 5 ps rise time sampling head The SD 22 amp SD 26 Sampling Heads are designed for use in the 11800 Series Digital Sampling Oscilloscopes the SM 11 Multi Channel Unit and the CSA 803 Series Communications Signal Analyzers SD 22 amp SD 26 Service Manual General Information Safety Summary 1 2 The general safety information in this part of the summary is for both operat ing and servicing personnel Specific warnings and cautions will be found throughout the manual where they apply but may not appear in this summary Terms in Manuals CAUTION statements in manuals identify conditions or practices that could result in damage to the equipment or other prop
44. nce Between Channels L Step 1 Initialize the instrument settings then make the following set tings in the order listed Sampling Head CH 1 SELECT CHANNEL On Instrument Mainframe ENHANCED ACCURACY button 11801 2 press UTILITY button 11801A B CSA 803 Series press Enhanced Accuracy 11801A B CSA 803 Series touch Calibrate All pop up menu Recall Defaults TRIGGER button ii eed week press SOUC DD Internal Clock Calibration Step Generator ON STANDBY switch ON C Step 2 Press the AUTOSET button 0 Step 3 Press the WAVEFORM button and then touch Horizontal Desc Step 4 Touch Main Record Length and then set Main Record Len to 1024 with the top knob Step 5 Touch Acquire Desc in the WAVEFORM major menu Step 6 Set Average N to On and then touch Set Avg Step 7 Set Average to 64 with the top knob 0 Step 8 Disconnect the calibration step generator remote head from CH 1 connect it to CH 2 and then press the CH 2 SELECT CHANNEL On Off button Step 9 Press AUTOSET L Step 10 Select the horizontal lt icon and then set the Main Size to 10 ps div L Step 11 Touch Acquire Desc and then set Average N to On in the Acquire Description pop up menu Step 12 Touch Exit L Step 13 Set the Main Pos so that the step is approximately centered on the screen L Step 14
45. o channel 17 5 ps rise time sampling head System Functional This section describes and illustrates the major functional blocks of the Overview SD 22 amp SD 26 Sampling Heads see Figure 4 1 500 Acquisition System Strobe Drive Strobe Strobe Dii To from Generator NIE Instrument Acquisition System 500 Figure 4 1 SD 22 SD 26 Sampling Head Block Diagram The strobe drive signal from the instrument mainframe controls the timing of the strobe assertion to each acquisition system and guarantees sampling coincidence between the two channels The strobe sense signal is a part of the strobe signal returned to the instru ment The instrument monitors the time duration of the strobe drive strobe sense loop and adjusts a delay line inside the instrument to maintain correct strobe timing SD 22 amp SD 26 Service Manual 4 1 Theory of Operation Loop Gain 4 2 Loop gain determines the sampling head s ability to accurately follow an input voltage change that occurs between two adjacent samples The accuracy with which the sampling head output follows the input signal is termed the dot transient response When loop gain is unity 1 the value of the first sample acquired after an input voltage change accurately reflects the voltage change indicating a good dot transient response see Figure 4 2 If loop gain is adjusted too low then the value of the first sample acquired after an input volta
46. on x 900 u Vnus Smoothing off lt 2 mVams Part 5 Rise Time yes SD 22 Sampling Head 28 ps SD 26 Sampling Head 17 5 ps Part 6 Acquisition no Aberrations with 067 1338 00 source 0 to 300 ps 796 to 12 300 ps to 5 ns 4 5 ns to 100 ns 1 2 100 0 6 10 ns to 20 ps 4 Part 7 Coincidence 10 ps no Between Channels Part 8 Maximum Signal 1 of step no Voltage amplitude Part 9 Isolation Between 1 no Channels 2 2 Checks and Adjustments Test Equipment SD 22 amp SD 26 Service Manual Checks and Adjustments Table 2 2 lists test equipment suggested for use with this manual Proce dure steps are based on the test equipment examples given but other equipment with similar specifications may be substituted Test results setup information and related connectors and adapters may be altered by the use of different equipment Table 2 2 Test Equipment Description Minimum Examples of Applicable Specification Test Equipment 11800 Series Tektronix digital Tektronix 11801 A B 11802 Oscilloscope or sampling oscilloscope Digital Sampling Oscilloscope CSA 803 Series Tektronix CSA 803 CSA Communications Signal Analyzer Pulse Generator Time Mark Generator Calibration Generator Calibration Step Generator System Controller 50 Termination SMA connectors 50 Termination BNC connectors Short Circuit Termination SMA connectors Coaxial Cable 50 2
47. orizontal gt icon and then set the Main Size to 200 ps div 0 Step 4 Press the WAVEFORM button and then touch Horizontal Desc O Step 5 Touch Main Record Length and then set Main Record Len to 1024 with the top knob O Step 6 Touch Acquire Desc in the WAVEFORM major menu 0 Step 7 Set Average N to On and then touch Set Avg N the Acquire Description pop up menu 0 Step 8 Set Average N to 1024 with the top knob 0 Step 9 Press the CH 2 SELECT CHANNEL button on the sampling head Step 10 Touch the vertical icon and then set the Vert Size M2 to 2 mV div O Step 11 Touch Acquire Desc in the WAVEFORM major menu and then set Avg N to On Step 12 Wait until the Acquire Desc selector in the WAVEFORM major menu shows that 1024 averages have been completed 0 Step 13 Touch the MEASURE button 0 Step 14 Touch Measurements and then Peak Peak in the Measurements pop up menu 0 Step 15 Record the CH 2 Peak Peak measurement for later use Step 16 Press the CH 1 SELECT CHANNEL button 2 37 Checks and Adjustments Step 17 Touch Measurements and then Peak Peak in the Measurements pop up menu Step 18 Record the CH 1 Peak Peak measurement for later use Step 19 Check that CH 2 Peak Peak CH 1 Peak Peak x 100 196 L Step 20 Disconnect the calibration step generator remote head from CH 1 and the 50 termination from CH 2 Connect the calibration step generator to CH 2 connect t
48. ormation you need for ordering replacement parts Parts List Item Names In the Replaceable Parts List an Item Name is separated from the descrip tion by a colon Because of space limitations an Item Name may some times appear as incomplete For further Item Name identification U S Federal Cataloging Handbook H6 1 can be used where possible Abbreviations Abbreviations conform to American National Standards Institute ANSI standard Y1 1 5 2 Replaceable Parts Replaceable Parts CROSS INDEX CODE NUMBER TO MANUFACTURER Mfr Manufacturer Code TK0435 LEWIS SCREW CO TK1163 XPOLYCAST INC TK1465 BEAVERTON PARTS MFG CO 0GZV8 HUBER AND SUHNER INC 0 05 NORTH STAR NAMEPLATE 02660 AMPHENOL CORP INDUSTRIAL TECHNOLOGY DIVISION ITD 13047 MAURY MICROWAVE CORP 20944 WILTRON CO 66598 CASCADE MICROTECH INC 80009 TEKTRONIX INC 98291 SEALECTRO CORP BICC ELECTRONICS SD 22 amp SD 26 Service Manual Address 4300 S RACINE AVE 9898 SW TIGARD ST 1800 NW 216TH AVE 500 WEST CUMMINGS PARK 1281 5 NE 25TH 720 SHERMAN AVENUE PO BOX 4340 8610 HELMS AVE 490 JARVIS DR 14255 SW BRIGADOON CT SUITEC 14150 SW KARL BRAUN DR PO BOX 500 40 LINDEMAN DR City State Zip Code CHICAGO IL 60609 3320 TIGARD OR 97223 HILLSBORO OR 97124 6629 WOBURN MA 01801 HILLSBORO OR 97124 HAMDEN CT 06514 CUCAMONGA CA 91730 4520 MORGAN HILL CA 95037 2809 BEAVERTON OR 97005 2360 BEAVERTON OR 97077 000
49. rd Len to 5120 with the top knob Step 5 Touch Acquire Desc in the WAVEFORM major menu Step 6 Set Average N to On and then touch Set Avg 0 Step 7 Set Average N to 128 with the top knob L Step 8 Touch the horizontal icon and then set the Main Size to 100 ns div Step 9 Touch Main Pos and then Set to Min in the Numeric Entry amp Knob Res pop up menu Step 10 Press the MEASURE button Step 11 Touch Measurements and then Rise in the Measurements pop up menu 0 Step 12 Touch Rise in the MEASURE major menu and then set Tracking to Off in the Rise pop up menu Step 13 Set the Main Size to 5 ns div L Step 14 Touch Baseline in the Rise pop up menu O Step 15 Touch a blank portion of the screen to exit this menu Step 16 Set the Baseline bottom knob to the average of the bottom of the pulse 10 ns before the step 0 Step 17 Touch the horizontal icon and then set the Main Pos so that the step is at the left most edge of the screen 2 24 Checks and Adjustments Checks and Adjustments Step 18 Set the Main Size to 20 ps div L Step 19 Set the Main Pos so that the step is approximately centered on the screen C Step 20 Touch Rise in the MEASURE major menu L Step 21 Record the Mean value in the Rise pop up menu for later use C Step 22 Calculate the sampling head rise time with the following formula sampling head _ 5 rise time Mean value Cali
50. required Serial Cable 1 ns rise time 5 V out put 10 Hz to 250 MHz frequency range 1 ns through 5 s markers in a 1 2 5 sequence at least 5 parts in 107 accuracy DC output 0 596 accuracy 1 V output amplitude Any compatible control ler with MS DOS and a serial port configured for COM 1 Impedance 50 O SMA male connector Impedance 50 O BNC connectors Male SMA compatible 50 Q 36 inch BNC male connectors 10 ft RS 232 C Cable 803A Communications Signal Analyzer Tektronix PG 502 Pulse Generator with a TM 500 Series Power Module Tektronix TG 501A Time Mark Generator with a TM 500 Series Power Module Tektronix PG 506A Calibration Generator with a TM 500 Series Power Module Tektronix Part 067 1338 0X Calibration Step Generator where X represents either a 0 1 2 3 5 or 6 depending on the power supply appro priate for your country Refer to Section 5 Replaceable Parts IBM compatible PC with terminal emulation software Tektronix Part 015 1022 00 Tektronix Part 011 0049 01 Tektronix Part 015 1020 00 Tektronix Part 012 0482 00 Tektronix Part 012 091 1 00 2 3 Checks and Adjustments Table 2 2 Test Equipment Cont Description Minimum Examples of Applicable Specification Test Equipment Adapter SMAto SMA male to BNC Tektronix Part 015 0554 00 BNC 2 required female Attenuator 2 x Attenuator 5 x Wrist Strap Static Control Mat Needl
51. strument and sampling head after each 2 000 hours of operation or every 24 months if used infrequently Procedures to perform periodic electrical checks are given in Section 2 Checks and Adjustments Static Sensitive Device Classification _caurion 9 Static discharge can damage any semiconductor component in the instrument or sampling head To prevent damage to the instrument or sampling head from electrostatic discharge follow all precau tions listed in this section The instrument and sampling head contain electrical components that are susceptible to damage from static discharge Table 3 1 gives relative sus ceptibility of various classes of semiconductors Static voltages of 1 kV to 30 kV are common in unprotected environments Observe the following precautions to avoid damage L Step 1 Minimize handling of static sensitive components L Step 2 Transport the sampling heads in their original containers and store the sampling heads on a metal surface or conductive foam Trans port the sampling heads with short circuit terminations on the inputs Label any package that contains static sensitive assemblies or components 3 1 Maintenance 3 2 0 Step 3 Discharge the static voltage from your body by wearing a wrist strap while handling these components Service of static sensitive assemblies or components should be performed only at a static free work station by qualified service personnel Use a static control mat an
52. tep 10 Touch Def Tra at the top of the screen O Step 11 In the Vertical Description pop up menu touch the following selectors in the order given Mainframe 11801 Series 1 Avg Mainframe 11801Series 1 Enter Desc 0 Step 12 Press the MEASURE button and then touch Measurements 0 Step 13 Touch RMS in the Measurements pop up menu and then RMS in the MEASURE major menu 0 Step 14 Set Data Interval to whole zone in the RMS pop up menu 2 21 Checks and Adjustments 0 Step 15 Examine that RMS is lt 800 HVnws for the SD 22 Sampling Head Examine that RMS is lt 1 2 mVnws for the SD 26 Sampling Head SN B020440 and above Examine that RMS is lt 2 mVnws for the SD 26 Sampling Head SN B010339 amp below Step 16 Press the WAVEFORM button L Step 17 Touch Sampling Head Fnc s and then set Smoothing to On in the Sampling Head Functions pop up menu 0 Step 18 Press the MEASURE button 0 Step 19 Examine that RMS is x 400 Vans for the SD 22 Sampling Head Examine that RMS is x 550 HVnws for the SD 26 Sampling Head SN B020440 and above Examine that RMS is 900 for the SD 26 Sampling Head SN B010339 amp below L Step 20 Repeat Steps 2 through 19 for CH 2 2 22 Checks and Adjustments Part 5 Rise Time Checks and Adjustments This part shows the setup and lists the procedure to check the rise time Specifications The specification for the SD 22 Sampling Hea
53. through 63 Step 54 Press the UTILITY button and touch Enhanced Accuracy 11801A B and CSA 803 Series or press the ENHANCED ACCURACY button 11801 2 Step 55 Touch Loop Gain 0 Step 56 Touch Recall Defaults in the Loop Gain Calibration pop up menu Step 57 Touch Exit Step 58 Touch Cursors at the top of the screen Step 59 Set Cursor 1 to the average of the bottom of the pulse before the step Step 60 Set Cursor 2 to the average of the bottom of the pulse after the step Step 61 Read the AV value and then record this value as VL for later use Step 62 Set Cursor 2 to the average of the top of the pulse and read AW Record this value as VH L Step 63 Examine that the negative dot response error VL VH x 100 is x 20 Checks and Adjustments Checks and Adjustments Check dot response at 1V with manual calibration settings by performing Steps 64 through 77 Step 64 Press the UTILITY button and touch Enhanced Accuracy 11801A B and CSA 803 Series or press the ENHANCED ACCURACY button 11801 2 Step 65 Touch Loop Gain Step 66 Set the Divide by Two Mode to Off in the Loop Gain Calibration pop up menu 0 Step 67 Touch Exit C Step 68 Remove the 5 x attenuator and then connect the 2 x attenuator between the channel you are using and the coaxial cable Step 69 Set the Vert Size M1 to 200 mV div Step 70 Set the pulse generator s amplitude for a 1 V 2
54. ts The procedures in this section provide a logical sequence of checks for performing a comprehensive performance verification procedure to verify that the sampling head meets specifications To functionally test the sam pling head perform the parts in Table 2 1 which have a yes in the Func tional Test column Refer to the SD 22 amp SD 26 Sampling Heads User Manual for more informa tion about specifications and sampling head operation Refer to Table 2 2 for information concerning test equipment used in the setups Table 2 1 Measurement Limits and Specifications Part and Description Measurement Specification Functional Limit Test Part 1 Power On none none yes Part 2 Dot Transient Response 250 mV with automatic lt 5 error yes calibration 500 mV with automatic lt 5 error no calibration 500 mV with default 2096 error no settings 1 0 V without automatic adjusted to 100 no calibration at1V Part 3 Offset Offset 2 mV yes Offset change with 5 no repetition rate SD 22 amp SD 26 Service Manual 2 1 Checks and Adjustments Table 2 1 Measurement Limits and Specifications Cont Part and Description Measurement Specification Functional Limit Test Part 4 Noise no SD 22 Sampling Head Smoothing on x 400 u Vnus Smoothing off lt 800 Vnus SD 26 Sampling Head SN B020440 and above Smoothing on x 550 u Vnus Smoothing off x 1 2 mVams SD 26 Sampling Head SN B010339 and below Smoothing
55. ued and pending The following are registered trademarks TEKTRONIX TEK TEKPROBE and SCOPE MOBILE WARRANTY Tektronix warrants that this product will be free from defects in materials and workmanship for a period of one 1 year from the date of shipment If any such product proves defective during this warranty period Tektronix at its option either will repair the defective product without charge for parts and labor or will provide a replacement in exchange for the defective product In order to obtain service under this warranty Customer must notify Tektronix of the defect before the expiration of the warranty period and make suitable arrangements for the performance of service Customer shall be responsible for packaging and shipping the defective product to the service center designated by Tektronix with shipping charges prepaid Tektronix shall pay for the return of the product to Customer if the shipment is to a location within the country in which the Tektronix service center is located Customer shall be responsible for paying all shipping charges duties taxes and any other charges for products returned to any other locations This warranty shall not apply to any defect failure or damage caused by improper use or improper or inadequate maintenance and care Tektronix shall not be obligated to furnish service under this warranty a to repair damage resulting from attempts by personnel other than Tektronix representatives to install r
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