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1. Options A1 A5 Internatlonal Power Cords Standard Optional 5 Instrument Enhancements llle Transportation Adds rr Cameras zs uum RT IESUS E EAR ee PEODOS cuc date eer edes qat e ala ei sape jean Viewing 05 APPENDIX A FACTORY SETTINGS APPENDIX B 067 0557 00 CALIBRATION FIXTURE 2246 1Y and 2246 Mod A Operators REV JUN 1989 7 45 7 45 7 46 7 47 7 47 7 48 7 48 7 50 7 50 7 51 7 52 7 53 7 53 7 54 7 55 7 55 7 56 7 56 LIST OF ILLUSTRATIONS Figure Page 1 1 The 2246A Oscilloscope 1 1 1 2 Optional power 1 5 2 1 CRT power and display 2 2 2 2 CH 1 and CH 2 vertical controls and connectors 2 4 2 3 Vertical connectors and CH 3 and CH 4 controls 2 6 2 4 Horizontal controls and indicators 2 8 2 5 Trigger controls and indicators 2 12 2 6 Rear panel u Rag 2 18 2 7 Menu controls ae aog v gece es TIC de SR xy C 2 20 3 1 Readout display 5 3 2 3 2 Graticule measurement markings 3 3 3 3 Voltmeter measurement channel menu
2. Within 496 2 3 MHz or more 3 degrees from dc to 100 kHz a i Performance Requirement not checked in manual 6 12 2246 1Y and 2246 Mod A Operators Performance Characteristics Table 6 1 cent Electrical Characteristics CHARACTERISTICS PERFORMANCE REQUIREMENTS EXTERNAL Z AXIS INPUT 1 8 volts or less Active Region Lower Threshold intensity decreases above this voltage Signal Required to Modu late an A or B Trace 3 8 volts or less provides noticeable modu lation of a normal intensity trace Usable frequency range is dc to 10 MHz External Z Axis signal does not affect the readout or the intensified zone intensity 30 V dc peak ac 30 V p p ac at 1 kHz or less 4 Maximum Input Voltage Represents less than one LSTTL load input Loading PROBE ADJUST OUTPUT Overshoot rising and 0 196 or less falling edge Output Voltage on PROBE ADJUST Jack Repetition Rate 0 5 V 1 into 1 load 1 kHz 25 FRONT PANEL SETUP MEMORY 2246 1Y Battery Life At least one year Two 1 5v 43 mAH silver oxlde button cells in series 2 FRONT PANEL SETUP MEMORY 2246 Mod A At least five years Battery Life 3 0 V 1200 mAH Type BR 2 3AE2P Lithium WARNING To avoid personal injury have battery replaced only by a qualified service person who understands proper han
3. 7 14 CH 1 and CH2 Vertical Deflection Accuracy 7 15 CH 3 and CH4 Vertical Deflection Accuracy 7 16 ADD Mode CH2 INVERT Deflectlon Accuracy 7 16 Vertical POSITION Range all channels 7 17 CH 1 to CH 2 Signal Delay Match 7 19 CH1 to CH 4 Signal Delay Match 7 19 CH 3 to CH 4 Signal Delay Match 7 20 CH 1 and CH 2 Vertical Bandwidth 7 20 CH and CH 4 Vertical 7 21 CH 1 CH 2 Aberrations 7 22 SCOPE BW Bandwidth Limit Accuracy 7 22 Common mode Rejection Ratio 7 23 Channel isolation Oa aoaia a ea ee 7 24 AC Coupled Lower 3 dB 7 25 Vertical ALT and CHOP 7 26 BEAM FIND Functional 7 26 A and B Trace 5 7 27 TRIGGERING 500 Hz Trigger 5 5 7 28 500 kHz Trigger 7 29 25 MHz Trigger 5 7 30 100 MHz Trigger 5 5 7 81 100 MHz NOISE REJ Trigger Sensitivity 7 82 Single Sweep 7 32 Trigger LEVEL Control Range 7 33 TV Field Trigger Sen
4. SO OBS GR Ae MODEL 2246 MOD A NSN 6625 01 275 4766 TA M CN A T 061 DAE DE D EM ib 5 t Y EEE Fat 4 gt BE Ro gt EXE 1 g ds A A i ae eRe ATTE ISO ARI A 56 AR 3 sty PR in Lin ie ed fe V UE AA SAT iol m dd As 7 E o 2 27 det ed ae Ton N T O 33A1 13 584 1 TE OPERATORS 070 7061 00 MANUAL Product Goup 46 22461 Y 2246 2H and 2246 Mod A PORTABLE OSCILLOSCOPES OPERATORS SN B100100 AND ABOVE Please Check for CHANGE INFORMATION at the Hear of This Manual THIS MATERIEL MAY BE REPRODUCED BY OR FOR THE U S GOVERNMENT PURSUANT TO THE COPYRIGHT LICENSE UNDER THE DFAR CLAUSE AT 52 227 7013 15 MAY 1987 DISTRIBUTION STATEMENT Distribution authorized to U S Government agencies only for administrative or operational use effective date is date of this manual Other requests for this document must be referred to San Antonio ALC MMEDT Kelly AFB TX 78241 5000 HANDLING AND DESTRUCTION NOTICE Comply with distribution statement and destroy by any method that will prevent disclosure of contents or reconstruction of the Tektronix COMMITTED TO EXCELLENCE First Printing JUN 1988 Revised JUN 1989 Copyright 1988 Tektronix Inc All rights reserved Contents of this publi cation may not be reproduced in any form without the written permission of Tektronix Inc
5. 3 6 3 4 Delay Time Delta Time channel menu 3 7 3 5 Voltmeter and Gated Measmt menus 3 9 3 6 Cursor Volts measurements menus 3 12 3 7 Time measurement 3 14 3 8 Service menu i e ee a re baden Ree Bees 3 20 3 9 Configure 3 22 3 10 Internal settings 3 24 4 1 Probe lt 4 4 5 1 PEAK voltage measurement and tracking cursors 5 4 5 2 Gated voltage 5 6 5 3 Voltage difference measurement using cursors 5 7 5 4 Voltage 5 9 5 5 Period measurement 5 11 5 6 Frequency 5 12 5 7 Rise time measurement 5 13 5 8 Making a phase difference measurement 5 16 5 9 Time difference between the two delays 5 19 5 10 A and B Track Trig Lvl cursors 5 20 5 11 Setting a specific trigger 5 23 vi 2246 1Y and 2246 Mod A Operators 5 12 Eliminating common mode signals 5 26 6 1 Maximum input voltage vs frequency derating curve for the CH 1 CH 2 CH 3 and CH 4 input connectors 6 15 6 2 Dimensional drawing standard cabinet 6 22 6 3 Dimensional drawing rackmount cabinet 2240 F
6. STANDARD INSTRUMENT Environmental instrument meets or exceeds the Requirements environmental requirements of MIL T 28800D for Type Ill Class 3 Style D equipment as described below Temperature Operating 10 C to 55 C 414 F to 4131 Non operating 51 C to 71 C 60 F to 160 F Tested to MIL T 28800D paragraphs 4 5 5 1 3 and 4 5 5 1 4 except in 4 5 5 1 3 steps 4 and 5 10 C operating test are performed ahead of step 2 7 51 C non operating test Equipment shall remain off upon return to room ambient during step 6 Excessive conden sation shall be removed before operating during step 7 Altitude Operating To 4 572 m 15 000 ft Maximum operating temperature decreases 1 C per 1000 ft above 5000 ft Non Operating To 15 240 m 50 000 ft Exceeds requirements of MIL T 28800D paragraph 4 5 5 2 Humidity Operating and Five cycles 120 hours referenced to Non operating MIL T 28800D paragraph 4 5 5 1 2 2 for type ill class 3 instruments Non operating and operating at 9596 096 to 4296 relative humidity Operating at 30 C and 55 C for all modes of operation Non operating at 30 C to 60 C Radiated and conducted Meets Category B Emission required per VDE 0871 a Performance not checked in manual 6 16 2246 1Y and 2246 Mod A Operators Performance Characteristics Table 6 2 cent Environmental Characteristics CHARACTERISTICS EMI Electrostatic Discharge Vibration operating
7. amp eee nr ABRE SUD eR 7 1 Test Equipment 7 1 Performance Check Interval 7 1 Preparation o cu s e ROS oec RR ease sce em ap ES 7 2 Index to Performance Check Procedure 7 6 DISPLAY an ara C 7 8 Trace Rotation gt ios doa osos 24 4 sa bee eh eae xci 7 8 Geomelty 2 6 uoto soos o oi out ies pas 7 9 VERTICALS 2 trt s dee re a ran 7 10 input COUPLING Functional Check 7 10 CH 1 and CH 2 VOLTS DIV Trace Shift 7 11 CH 3 and CH 4 VOLTS DIV Trace Shift 7 12 CH 1 and CH 2 VAR VOLTS DIV Trace Shift 7 12 CH 1 and CH 2 Input Coupling Trace Shift 7 13 CH 2 INVERT Trace Shift 7 13 2246 1Y and 2246 Mod A Operators iii CH 1 CH 2 VAR VOLTS DIV Range 7 13 Low Frequency Linearity Check 7 14 CH 1 and CH 2 Vertical Deflection Accuracy 7 15 CH 3 CH 4 Vertical Deflection Accuracy 7 16 ADD Mode and CH 2 INVERT Deflection Accuracy 7 16 Vertical POSITION Range all channels 7 17 CH 1 to CH 2 Signal Delay Match 7 19 CH 1 to CH 4 Signal Delay 7 19 CH 3 to CH 4 Signal Delay Match 2 7 20 Ch 1 and CH 2 Vertical Bandwidth 7 20 CH 3 and CH 4 Vertical Bandwidth 7 21 Ch 1 and CH 2 Aberra
8. ins n A AUTO LEVEL RUNS AFTER CH 1 DC As selected OFF A 1 Appendix A Table A 1 cont Factory Settings Controls Settings TRACKING CURSORS TRACK MEASMT MENU Displays OFF CONFIGURE Selections NO A INTEN INTEN READOUT As selected A 2 2246 1Y and 2246 Mod A Operators Appendix B 067 0557 00 CALIBRATION FIXTURE When connected to a Calibration Fixture Tektronix part number 067 0557 00 for GPIB control during calibration the 22461 Y or 2246 Mod A SN B1 00100 and up oscilloscope acts as a listener only GPIB device and allows control of front panel switches When the Calibration Fixture Is connected all front panel switches except POWER are disabled Front panel Indicators and crt displays are not disabled allowing the user to view oscilloscope control settings during calibration Front panel controls which are continuously variable e g Vertical POSITION controls cannot be con trolled via the GPIB and are always under operator control during calibration Installation To connect the Calibration Fixture to a 2246 1Y or 2246 Mod A 1 Remove the access cover located on the top of the instrument case 2 Connect the male connector from the Calibration Fixture to the female receptacle located under the access cover For More Information Refer to the 067 0557 00 Calibration Fixture Instruction manual for detailed operating instructions and the GPIB command set for controlling the 2246 1 Y or 2
9. BNC coaxial cable and a 50 BNC termination C Set generator for 2 ms time marks d CHECK sweep length of the A trace is greater than 10 divisions 7 36 2246 1Y and 2246 Mod A Operators Performance Check Procedure Set Horizontal MODE B B SEC DIV 1ms A B SELECT B Trigger TRIGGER MODE RUNS AFTER or DELAY Control CCW to the lowest DELAY readout value B INTEN For a visible display f CHECK the Delay Time readout is 0 000 ms and the B Sweep length is greater than 10 divisions 2 Horizontal POSITION Range a Set Horizontal MODE A Horizontal POSITION Fully CW b CHECK that the start of trace positions past the center vertical graticute line c Set Horizontal POSITION fully CCW d CHECK that the 1 1th time marker Is positioned to the left of the cen ter vertical graticule line 3 VAR SE C DIV Range a Set SEC DIV 1ms SEC DIV VAR Fully CCW Horizontal POSITION 12 o clock b Set time mark generator for 5 ms time marks c CHECK the time mark spacing is equal to or less than two divisions d Set SEC DIV VAR fully CW calibrated detent 2246 1Y and 2246 Mod A Operators 7 37 Performance Check Procedure 4 Magnifier Registration a Set X10 MAG on b Position the rising edge of a time marker to the center vertical graticule line Set X10 MAG off d CHECK for less than 0 5 division horizontal trace shift 5 A and B Timing Accuracy and Linearity a Set A SEC DIV t
10. DC Inverter Power Supply Service Manual Transportation Aids Carrying Strap Portable Instrument Cart Cameras Low Cost Scope Camera Motorized Camera High Performance Camera Probes Active Probe Power Supply for Active Probe Current Probes Environmental Probe High Voltage Probe 1 X1 10X Passive Probe Subminiature 10X Probe Ground Isolation Monitor Isolator for floating measurements Viewing Hoods Collapsible Viewing Hood Binocular Viewing Hood Polarized Collapsible Viewing Hood 2246 1Y and 2246 Mod A Operators Part Number 200 3232 00 016 0857 00 016 0848 00 337 2775 01 2240F1R 1105 070 7062 00 346 0199 00 K212 C5 Option 02 C7 Options 03 and 30 C30B Option O1 P6202A 1101A P6021 1 52 m P6022 1 52 m A63021AM503 A63031AM503 P6008 1 83m P6009 2 74m P6063B 1 83m P6130 2m A6901 A6902B 016 0592 00 016 0566 00 016 0180 00 REV JUN 1989 8 3 APPENDICES FACTORY SETTINGS 067 0557 00 CALIBRATION FIXTURE 2246 1Y and 2246 Mod A Table A 1 Factory Settings Controls VERTICAL MODE CH 1 CH 2 INPUT COUPLING CH 1 2 3 4 VOLTS DIV CH 2 INVERT SCOPE BW HORIZONTAL MODE X10 MAG A SEC DIV B SEC DIV A B SLOPE A B SELECT A TRIGGER MODE B TRIGGER MODE A and B TRIGGER SOURCE A and B TRIGGER COUPLING TRIGGER HOLDOFF MEASUREMENTS 2246 1Y and 2246 Mod A Operators Appendix A Settings CH 1 AND CH 2 DC 0 1V OFF OFF OFF 0 1 ms
11. Use the Trigger LEVEL control to position the trigger level cursor to about 3 V measured from the ground cursor For the assumed signal this level is ample to avoid triggering on the lower amplitude signals in the display For other waveforms the user must determine what trigger level is needed to obtain triggering on a specific waveform amplitude Apply the signal to the appropriate input channel connector and set the Input COUPLING to DC The waveform display will now appear assuming the A INTENSITY is set to a viewing level and it will be triggered on the larger amplitude pulses of the signal Once triggering is obtained the A SEC DIV setting may be set to a faster Sweep speed to expand the triggering pulse for making any measurements wanted Use of the Add Mode With the VERTICAL MODE set to ADD the resulting waveform is the algebraic sum of the signals applied to the Channel 1 and Channel 2 inputs CH 1 CH 2 A plus symbol appears In the readout between the CH 1 and CH 2 VOLTS DIV setting readout to indicate that ADD is active If the CH 2 INVERT feature is turned on INVERT button lit the waveform displayed is the difference between the signals applied to the Channel 1 and Channel 2 Inputs Neither the CH 1 nor CH 2 waveform needs to be displayed to obtain the ADD trace but any or ALL vertical input channels may be displayed at the same time if wanted by the user When the VOLTS DIV switches of CH 1 and CH 2 are bot
12. 8th 6 945 ms to 7 055 ms 9th 7 940 ms to 8 060 ms 8 935 ms to 9 065 ms 7 42 2246 1Y and 2246 Mod A Operators Performance Check Procedure e CHECK that the intensified dot is positioned at or after the 99th time marker located at a Delay Time of 9 9 ins f Disconnect the time mark generator from the 2246 1Y or 2246 Mod A 10 X AXIS Gain Accuracy a Set Horizontal MODE x Y VERTICAL MODE CH 2 CH 1 off CH 1 and CH 2 VOLTS DIV 10 mV CH 1 Input COUPLING DC CH 2 Input COUPLING GND b Connect calibration generator STD AMPL output to the CH 1 input via a 50 precision BNC coaxial cable c Set calibration generator for Std Ampl output 50 mV d CHECK X Axis amplitude is between 4 85 and 5 15 horizontal divisions e Disconnect calibration generator 11 X Y Phase Difference a Set HORIZONTAL MODE A A SEC DIV 1 ms CH 1 VOLTS DIV 0 2 v VERTICAL MODE CH 1 CH 2 off CH 1 Input COUPLING DC b Connect function generator FG 502 output to the CH 1 Input via a 50 BNC coaxial cable and a 50 BNC termination Set function generator output for six divisions of signal display ampli tude at 100 kHz 2246 1Y and 2246 Mod A Operators 7 48 Performance Check Procedure 12 Set Horizontal MODE X Y CH 1 Input COUPLING GND Position dot to graticule center Set CH 1 Input COUPLING to DC CHECK ellipse opening at the center is 0 3 division or less measured horizontally Disconnect functi
13. Bench Handling Test cabinet on and cabinet off DESCRIPTION Meets the following requirements in accordance with MIL T 28800D and MIL STD 461C CE 01 Part 2 narrow band require ments up to 15 kHz CE 03 Part 4 CS 01 Part 2 CS 02 Part 2 CS 06 Part 5 limited to 300 V RE 01 Parts 5 and 6 except meas ured at 12 inches RE 02 Part 2 full limits to 1 GHz RS 02 Part 2 part 1 RS 02 Part 2 part Il limited to 5 A at 60 Hz RS 03 Part 2 limited to 1 GHz Withstands discharge of up to 20 kV Test performed with probe containing a 500 pF capacitor with 1 series resistance charged to the test voltage Conforms to Tektronix Standard 062 2862 00 15 minutes along each of 3 major axes at a total displacement of 0 025 inch p p 4 g at 55 Hz with frequency varied from 10 Hz to 55 Hz to 10 Hz in one mlnute sweeps Hold for 10 minutes at 55 Hz In each of the three major axes All major resonances must be above 55 Hz Meets requirements of MIL T 28800D paragraph 4 5 5 3 1 Each edge lifted four inches and allowed to free fail onto a solid wooden bench surface Meets requirements of MIL T 28800D paragraph 4 5 5 4 3 2246 1Y and 2246 Mod A Operators 6 17 Performance Characteristics Table 6 2 cent Environmental Characteristics CHARACTERISTICS DESCRIPTION Transportation Meets the limits of the National Safe Transit Association test procedure 1A B 1 excursion of
14. Products of Tektronix Inc and its subsidiaries are covered by U S and foreign patents and or pending patents TEKTRONIX TEK SCOPE MOBILE and um are registered trademarks of Tektronix Inc Printed in U S A Specification and price change privileges are reserved INSTRUMENT SERIAL NUMBERS Each instrument has a serial number on a panel insert tag or stamped on the chassis The first number or letter designates the country of manufac ture 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 ldentified as follows B000000 Tektronix Inc Beaverton Oregon U S A G100000 Tektronix Guernsey Ltd Channel Islands E200000 Tektronix United Kingdom Ltd Marlow J300000 Sony Tektronix Japan H700000 Tektronix Holland NV Heerenveen The Netherlands HK00000 Hong Kong Repackaging for Shipment Save the original shipping carton and packing material in case it is ever necessary to reship the instrument by a commercial transport carrier If the original materials are unfit or not available then repackage the instru ment using the following procedure 1 Use a corrugated cardboard shipping carton with a test strength of at least 275 pounds and an inside dimension at least six inches greater than the instrument dimensions Enclose the following information owner s address name and
15. Provide Composite TV Video and Line Sync Signals Item and Description Example of Test Equipment Check TV TV Signal AR Trigger circuit Generator TEKTRONIX 067 0601 00 Calibration Fixture with 067 5002 00 525 60 and 067 5010 00 1201 60 plug ins TEKTRONIX DM501A Digital Multimeter Digital De Voits Range Power supply Multimeter 0 to 140 V De voltage checks DMM Voltage accuracy and adjustments 40 15 4 1 2 digit display BNC Coupling Capacitor CH1 CH2 Voltmeter DC rejection ratio check TEKTRONIX 015 0221 00 Coupling Capacitor 0 047 pF Requires a TM500 series power Module 2246 1Y and 2246 Mod A Operators Performance Check Procedure ISOM NAGTAWND gt e NN 8 SR SHMANAGTAWN gt INDEX TO PERFORMANCE CHECK PROCEDURE DISPLAY TRAGE ROTATION 423 2er enden 7 8 Geomelty don e hor er Eoo RUN a ROS D RE ee 7 9 VERTICAL input COUPLING Functional 7 10 CH 1 and CH 2 VOLTS DIV Trace 7 11 CH 3 and CH 4 VOLTS DIV Trace 7 2 CH 1 and CH 2 VAR VOLTS DIV Trace Shift 7 12 CH 1 and CH 2 input COUPLING Trace Shift 7 13 CH 2 INVERT Trace 5 7 13 CH1 and CH 2 VARVOLTS DIV 7 13 Low Frequency
16. Set A SEC DIV 1ms VERTICAL MODE CH 1 others off Horizontal MODE ALT B SEC DIV 0 5 ms A B SELECT B B Trigger MODE RUNS AFTER TRACE SEP Fully CW b Position the CH 1 trace below the center horizontal graticule line to display the separated B trace c CHECK for at least four divisions of upward trace separation between the B trace and the A trace d Set TRACE SEP fully CCW e Position the CH 1 trace above the center horizontal graticule line to display the separated B trace f CHECK for at least four divisions downward trace separation of the B trace from the A trace 2246 1Y and 2246 Mod A Operators 7 27 Performance Check Procedure TRIGGERING Equipment Required See Table 7 1 Leveled sine wave generator Function generator 50 BNC coaxial cable 10X BNC attenuator 2X BNC attenuator 50 Q termination Dual Input coupler TV signal generator 1 500 Hz Trigger Sensitivity a Set READOUT intensity For a viewable readout A INTEN For a viewable trace VERTICAL MODE CH1 CH 1 and CH 2 Input COUPLING DC CH 1 VOLTS DIV 0 1 v Horizontal MODE A A SEC DIV 2 ms A B SELECT A Trigger TRIGGER MODE AUTO LEVEL TRIGGER SOURCE VERT TRIGGER CPLG AC TRIGGER SLOPE positive going TRIGGER HOLDOFF Min FOCUS For best defined display Measurements All off press CLEAR DISPLAY three times Horizontal POSITION 12 clock b Connect function generator FG 502 output to the CH 1 input via a 50
17. VERTICAL MODE CH 1 CH 2 off CH 1 VOLTS DIV 10 mV SCOPE BW On b Set calibration generator AMPLITUDE to 20 mV c Move the test signal to the CH 1 Input d Position the top of the signal to top graticule line e Check the signal amplitude is between 1 9 and 2 1 divisions f Set bottom of the signal to bottom graticule line g Check the signal amplitude is between 1 9 and 2 1 divisions h Repeat the procedure for CH 2 7 14 2246 1 Y and 2246 Mod A Operators Performance Check Procedure g CH 1 and CH 2 Vertical Deflection Accuracy a Set CH 2 VOLTS DIV to 2 mV b Set calibration generator AMPLITUDE to 10 mV c Position the trace two graticule lines below the center graticule line d CHECK all positions of the VOLTS DIV settings for correct signal to graticule accuracy using the settings In Table 7 2 for the checks e Set calibration generator AMPLITUDE to 10 mV f Move the test signal to the CH 1 input g Set VERTICAL MODE CH 1 CH 2 off CH 1 VOLTS DIV 2 mV h Position the trace two graticule lines below the center graticule line 1 Repeat CHECK procedure for CH 1 Table 7 2 Signal to Graticule Accuracy Calibration Generator AMPLITUDE Setting VOLTS DIV Setting Deflection Accy in divisions 4 90 to 5 10 5 mV 3 92 to 4 08 10 mv 4 90 to 5 10 20 mV 4 90 to 5 10 50 mv 3 92 to 4 08 0 1V 4 90 to 5 10 0 2 V 4 90 to 5 10 0 5 V 3 92 to 4 08 1v 4 90 to 5 10 2V 4 90
18. and CH 2 input connectors via a 50 precision BNC coaxial cable a 50 BNC termination and a BNC dual input coupler Set the leveled sine wave generator output for an eight division signal display amplitude at 50 kHz Set ADD MODE On CH 2 VOLTS DIV 10 mV CH 2 INVERT On CH 1 VERTICAL MODE off SCOPE BW off Adjust CH 1 or CH 2 VAR VOLTS DIV for smallest signal amplitude as needed Set the leveled sine wave output frequency to 10 MHz Set CH 1 VERTICAL MODE On ADD MODE off Set the leveled sine wave output amplitude for an eight division display Set the VERTICAL MODE to ADD CH 1 off CHECK the signal Is less than 0 3 division In amplitude Set the leveled sine wave generator frequency to 100 MHz Set VERTICAL MODE to CH1 ADD off Set the leveled sine wave output amplitude for an eight division display Set the VERTICAL MODE to ADD CH 1 off CHECK the signal is less than 0 8 division in amplitude 2246 1Y and 2246 Mod A Operators 7 23 Performance Check Procedure 21 Disconnect the test setup Set both CH 1 and CH 2 VAR controls to their calibrated fully clock wise In detent positions Channel Isolation Set VERTICAL MODE CH 1 and CH 2 ADD off CH 2 INVERT off CH 1 CH 2 CH 3 and CH 4 VOLTS DIV 0 1 v TRIGGER SOURCE CH 1 Connect the leveled sine wave generator SG 503 output to the CH 1 input via a 50 precision BNC coaxial cable and a 50 BNC termination Set th
19. p p viewed over two seconds with Trigger LEVEL control set at mid level but not at control extremes COUPLING DC 0 35 division from dc to 25 MHz increasing to 1 0 division at 100 MHz NOISE REJECT 1 4 division from dc to 25 MHz increasing to 2 2 division at 100 MHz 0 5 division or less will not trigger HF REJECT 0 35 division from dc to 50 kHz attenuates signals above upper 3 dB cutoff frequency of 70 kHz LF REJECT 0 35 division from 100 kHz to 25 MHz increasing to 1 0 division at 100 MHz attenuates signals below the Iwer 3dB cutoff cutoff frequency of 50 kHz AC 0 35 division from 50 Hz to 25 MHz increasing to 1 0 division at 100 MHz attenuates signals below the lower 3dB cutoff frequency of 20 Hz TV LINE TV FIELD 0 5 division of composite sync will achieve a stable display Free Run Enable Frequency AUTO and The sweep will free run if trigger source AUTO frequency is less than 10 Hz LEVEL In AUTO LEVEL if the trigger source frequency is 25 Hz the range of the Trigger LEVEL control may be reduced 6 8 2246 1Y and 2246 Mod A Operators Performance Characteristics Table 6 1 cent Electrical Characteristics CHARACTERISTICS PERFORMANCE REQUIREMENTS LEVEL Control Range AUTO NORM t 20 divisions referred to the appropriate SGL SEQ vertical input This range is sufficient to allow triggering at any point on a displayed waveform for all modes except ADD In ADD the com bine
20. 4 1 Trace Rotation Adjustment 4 2 Probe Low Frequency Compensation 4 3 Vertical Deflection Check 4 4 Timirig Checks i uoo Rogo ht RE A ee 4 5 ii 2246 1Y and 2246 Mod A Operators SECTION 5 BASIC APPLICATIONS Introduction dee eee Mee ee e ub n ns 5 1 CH 1 CH 2 Voltmeter Measurements 5 1 Peak Voltage Measurement 5 2 Gated Voltage Measurement 5 4 Voltage Measurement 5 6 Voltage Difference 5 6 Ground Referenced 5 8 Time Measurement Cursors llle 5 10 Time Difference es 040 Le ee 5 10 Period 5 11 Frequency 5 11 Rise Time Measurements 5 12 Phase Measurements 5 14 Time Delay Measurement 5 17 Track Trigger Level Cursors 0 0 5 19 Setting Trigger 5 23 Use of the Add 5 24 SECTION 6 PERFORMANCE CHARACTERISTICS Introduction oer ms et SL ROR ewe uerus ee Me ES 6 1 Recommended Calibration 5 6 1 SECTION 7 PERFORMANCE CHECK PROCEDURE Introduction s ax
21. 5 5 3 3 GIOUNGING s Hr ee Beas a at re RR be ape hy es 3 3 Probes Ces tieu tu SR IN ea o aM n 3 4 Coaxial Cables 3 4 External Triggering gr PIDEN MV 3 4 MENU SYSTEM OPERATION 3 5 Introduetion SN un cee 3 5 Clearing the Menu and Cursors Display 3 5 Setting Measurement Channel 3 6 Recalling the Last Measurement Mode 3 8 Channel land Channel 2 Voltmeter 3 8 Voltmeter Measurements 1 3 10 Voltmeter Measurements Page 2 GATED Measurements 3 10 Cursors Measurements 3 11 Time Menus a 3 13 Conditions for Cursors Display 3 16 Measurement Cursors 3 16 Track Trig Lvl Cursors e 3 16 Track th Cursors 3 17 Behavior for Horizontal Mode Changes 3 17 Measurement Compatibility and Error Messages 3 18 Measurements in Single Sequence 3 19 Service Menu Features 3 20 Configure Menu 3 21 Self Cal 5 3 23 Internal Settings Menu 3 23 SECTION 4 OPERATOR CHECKS AND ADJUSTMENTS Introductions a n dom due I SC a 00 bo 4 1 Initial Setup sss 2a ok b e ee ea
22. 500 kHz 2246 1Y and 2246 Mod A Operators 7 29 Performance Check Procedure Add a 10X and a 2X BNC attenuator before the 50 BNC termination for a 0 35 division display amplitude CHECK that the display cannot be triggered in either HF REJ of NOISE REJ CPLG Set Horizontal MODE B A B SELECT B Trigger B SEC DIV 14S CHECK that the display cannot be triggered in HF REJ or NOISE REJ CPLG by adjusting the Trigger LEVEL control 3 25 MHz Trigger Sensitivity a Set Horizontal MODE A A B SELECT A Trigger TRIGGER CPLG DC A SEC DIV 50 ns b Remove the 10X and 2X BNC attenuators from the signal path Set leveled sine wave generator output to produce a 7 0 division dis play amplitude at 25 MHz d Add a 10X and a 2X BNC attenuator before the 50 BNC termination e CHECK that the display Is stably triggered in DC LF REJ and AC Trigger CPLG the display is not triggered in NOISE REJ and HF REJ Trigger CPLG settings Set TRIGGER CPLG AC Horizontal MODE B A B SELECT B Trigger B SEC DIV 20 ns CHECK that using the Trigger LEVEL control the display can be stably triggered in DC LF REJ and AC Trigger CPLG the display can not be triggered In NOISE REJ and HF REJ Trigger CPLG settings 7 30 2246 1Y and 2246 Mod A Operators Performance Check Procedure h Set leveled sine wave generator SG 503 to produce a 1 4 division display at 25 MHz i CHECK that the display can be stably triggere
23. 6 2246 1Y and 2246 Mod A Operators Performance Characteristics Table 6 1 cent Electrical Characteristics CHARACTERISTICS PERFORMANCE REQUIREMENTS HORIZONTAL DEFLECTION SYSTEM cont X10 Magnifier Expands the normal sweep by ten times around that portion of the sweep positioned at the center vertical graticule line Registration 2 divisions or less shift X10 to X1 Variable Control Range Continuously variable between calibrated SEC DIV settings Extends both the A and B sweep time per division by at least a factor of 2 5 Sweep Length Greater than 10 divisions Delay Time Delay Control Range Less than 0 1 division to 10 times the A SEC DIV switch setting Maximum value does not exceed end of the A Sweep Jitter 1 part in 20 000 or less peak to peak during a two second time interval Delta Time Delta Control Range From 0 5 division or less to the right of setting of DELAY control to within 1 5 divisions of the end of the A sweep a Performance Requirement not checked in manual 2246 1Y and 2246 Mod A Operators 6 7 Performance Characteristics Table 6 1 cent Electrical Characteristics CHARACTERISTICS PERFORMANCE REQUIREMENTS A AND B TRIGGER Sensitivity CH 1 through CH 4 AUTO LEVEL NORM AND SINGLE SEQUENCE Trigger sensitivity is defined as the minimum peak to peak sine wave trigger signal amplitude required to show the test signal with horizontal Jitter of less than 3 0 of one period
24. BNC coaxial cable and a 50 BNC termination c Set function generator FG 502 output to produce a 7 0 division sine wave display at 500 Hz d Add 10X and a 2X BNC attenuator before the 50 BNC termination for a 0 35 division display 7 28 2246 1Y and 2246 Mod A Operators Performance Check Procedure NOTE The TRIGGER LEVEL control may be used to obtain a stable display y CHECK that the display Is stably triggered with DC HF REJ and AC Trigger CPLG and that the display will not trigger on NOISE REJ or LF REJ Trigger CPLG Set TRIGGER CPLG DC A B SELECT B Trigger TRIGGER MODE NORM TRIGGER SOURCE VERT TRIGGER SLOPE positive going Horizontal MODE B B SEC DIV 0 5 ms DELAY Time 0 000 minimum delay time B INTEN For viewable display NOTE It may be necessary to adjust the TRIGGER LEVEL control to obtain a display g CHECK that using the Trigger LEVEL control the display can be h stably triggered in DC HF REJ and AC Trigger CPLG and that the display cannot be triggered in NOISE REJ or LF REJ Trigger CPLG Disconnect the test setup from the CH 1 input 2 500 kHz Trigger Sensitivity a Set Horizontal MODE A A B SELECT A Trigger A SEC DIV 2 us Connect a leveled sine wave generator SG 503 output to the CH 1 input via a 50 BNC coaxial cable and 50 BNC termination Set leveled sine wave generator output to produce a 7 0 division sine wave display amplitude at
25. PHASE Cursor positioning for delay and delta time setting are identical to the SEC mode The value displayed for the phase measurement readout has units of degrees and is calculated by the following formula time difference Phase in degrees reference time 360 The reference time is set using the l SET 360 gt I menu selection that appears along with the PHASE choice when phase measure ments are selected If the reference is already set to the desired reference value pressing the PHASE menu selection exits the menu and activates the phase measurement mode SET 360 Permits resetting of the 360 reference for the l PHASE measurements Cursor difference or delay time to delta time difference is taken as the reference value when exiting the SET 360 reference function Set the desired time that represents the complete 360 degrees of a reference waveform using the Ik OR 2246 1Y and 2246 Mod A Operators 3 15 Operators _Familiarization DELAY and controls then select I PHASE to exit the menu and continue the phase measurement Recalling the LAST MEAS MT when PHASE was the last selected measurement mode recalls the 360 degree reference as well SELF CAL Self characterizes the horizontal system SELF CAL may be performed at any time Suggested times are after a warmup period whenever the ambient operating temperature changes by 15 C and just prior to making any time measu
26. Peak and Peak to Peak Volts Accuracy Connect the leveled sine wave generator SG 503 output to the CH 2 input via a 50 BNC coaxial cable and a 50 BNC termination Set CH 2 VOLTS DIV to 20 mV Set leveled sine wave generator output for a readout of 100 0 mV 0 5 mV at 50 kHz Set leveled sine wave generator output for 25 MHz CHECK the readout is between 95 0 mV and 105 0 mV Set CH1 CH2 VOLTMETER to PEAK CHECK the readout Is between 46 0 mV and 54 0 mV Set CH1 CH2 VOLTMETER to PEAK CHECK the readout Is between 46 0 mV and 54 0 mV 100 MHz Peak Peak and Peak to Peak Volts Accuracy Set leveled sine wave generator SG 503 output frequency to 100 MHz CHECK the readout is between 34 4 mV and 54 0 mV Set CH1 CH2 VOLTMETER to PEAK CHECK the readout Is between 34 4 mV and 54 0 mV Set CH1 CH2 VOLTMETER to PK PK 2246 1Y and 2246 Mod A Operators 7 53 Performance Check Procedure f CHECK the readout is between 69 7 mV and 107 0 mV Disconnect the leveled sine wave signal from the 2246 1Y or 2246 Mod A Gated Volts Accuracy Set A SEC DIV 0 5 ms CH 2 VOLTS DIV 10 mV Set CH1 CH2 VOLTMETER to GATED PEAK Connect calibration generator PG 506 Std Ampl output to the CH 2 input via a 50 precision BNC coaxial cable Set the generator to Std Ampl output 50 mV Set delta TIME POSITION to minimum Intensified zone width CHECK that the width of the dot Is less than 0 2
27. Readout calculated from SEC 9 cursor positions 0 5 of reading 2 of the VOLTS DIV setting high frequency display errors 0 5 of reading 2 of the VOLTS DIV setting high frequency display errors Readout calculated from SEC cursor positions Within 0 05 vertical division Within 0 05 vertical division 2246 1Y and 2246 Mod A Operators REV AUG 1988 6 11 Performance Characteristics Table 6 1 cent Electrical Characteristics CHARACTERISTICS PERFORMANCE REQUIREMENTS TRACK GROUND Position Accuracy Within 0 05 vertical division Cursor position on waveform versus baseline displayed with grounded input DELTA TIME FUNCTIONS DELTA TIME Accuracy 15 C to 35 C 1 0 of reading 1 0 of one division of the A Sweep 10 C to 15 C and 35 C to 55 C 2 0 of reading 1 0 of one division of the A Sweep DELTA 1 TIME Accuracy Readouts calculated using DELTA TIME difference DELTA Phase Accuracy Readouts calculated using DELTA TIME difference Delay Accuracy A Sweep 0 5 of reading 5 0 of one division Trigger Point to Start of of the A Sweep 25 ns B Sweep X Y OPERATION Deflection Factors Same as Vertical deflection system with the VOLTS DIV variable controls in calibrated detent position Accuracy X Axis 15 C to 35 C 10 C to 15 C and 35 C to 55 C Horizontal X Axis 3 dB Bandwidth Phase Match DC Coupled Within 3
28. The 2246 1Y and 2246 Mod A operates on line voltages from 90 to 250 V with line frequencies ranging from 48 to 440 Hz No line voltage selecting is necessary Instruments are shipped with the power cord that was requested on the order The power cord must match the power source outlet if it does not contact your Tektronix representative or local Tektronix Field Office See Figure 1 2 for optional power cords available WARNING For electrical shock protection insert this plug into a power source outlet that has a properly grounded protective ground contact 1 4 2246 1Y and 2246 Mod A Operators Introduction Reference Standards b Plug Power Cord Line Configuration Plug Type Voltage ANSI C73 11 U S NEMA 5 15 P 120V 120V 83 UL 198 6 7 EURO I IV VII 220V 220V IEC 83 IEC 127 BS 1363 IEC 83 IEC 127 a AN 240V AS C112 240V IEC 127 Australian 240V ANS C73 20 North NEMA 6 15 P American 240V IEC 83 240V UL 198 6 Switzerland 220V 220V A 6A type C fuse is also installed inside the plug of the Option A2 power cord gt Reference Standards Abbreviations ANSI American Nationa Standards Institute AS Standards Association of Australia BS British Standards Institution CEE International Commission on Rules for the Approval of Electrical quipment IEC International Electrotechnical Commission NEMA Nation
29. UNWANTED LINE FREQUENCY COMPONENT CH 2 SIGNAL FROM LINE FREQUENCY SOURCE SIGNAL WITH LINE FREQUENCY COMPONENT CANCELLED Figure 5 12 Eliminating common mode signals 2246 1Y and 2246 Mod A Operators Basic Applications h Select ADD and then turn on CH 2 INVERT unless cancellation signal is already 180 out of phase Turn off the CH 1 and CH 2 displays and slightly readjust the CH 2 VOLTS DIV VAR control for maximum cancellation of the line frequency component see Figure 5 12B i The SEC DIV setting may be set to a faster sweep speed to expand the waveform and the display amplitude may be increased by advancing both VOLTS DIV switches and readjusting the VOLTS DIV VAR controls as necessary to maintain cancellation of the undesired signal component 2246 1Y and 2246 Mod A Operators 5 27 SECTION 6 PERFORMANCE CHARACTERISTICS 2246 1Y and 2246 Mod A Performance Characteristics Introduction Electrical characteristics in Table 6 1 apply when the 2246 1Y and 2246 Mod A has been calibrated at an ambient temperature between 20 C and 30 C has warmed up at least 20 minutes and is operating in an ambient temperature between 10 C and 55 C unless otherwise noted Items listed in the Performance Requirements column are verifiable quali tative or quantitative limits that define the measurement capabilities of the instrument Environmental Specificat
30. V square wave signal at about 1 kHz for compensating voltage probes and checking the vertical deflection accuracy Auxiliary Ground Jack Provides an auxiliary chassis ground con nection banana jack between the equipment under test and the 2246 1Y or 2246 Mod A 21 Channel 3 and Channel 4 POSITION Controls Adjust vertical position of Channel 3 and Channel 4 signal displays 22 3 and Channel 4 VOLTS DIV Switches Select two basic deflection factors for Channel 3 and Channel 4 0 5 volt division but ton lit or 0 1 volt division button not lit The VOLTS DIV switch setting displayed in the crt readout reflects the attenuation factor of coded attenuator probes that are connected to the vertical inputs 23 3 CH 4 Input Connectors Connect signals to the inputs of the Channel 3 and Channel 4 vertical attenuators Input coupling is dc only The input connectors are BNC with probe coding ring contacts the same as Channel 1 and Channel 2 The limited choice of deflection factors for the Channel 3 and Channel 4 inputs makes them useful for digital and trigger signals Horizontal Refer to Figure 2 4 for location of items 24 through 31 POSITION Control Adjusts the horizontal position of the waveform displays on the crt X10 MAG Switch Magnifies the normal sweep by a factor of 10 and extends the fastest sweep speed to 2 ns per division The center portion of an unmagnified sweep display will be
31. are used for this function also Set up all the controls and apply the signal to be measured in the same way but after pressing the VOLTMETER CH1 CH2 button select the TO GATED MEASMT MENU choice After that follow these additional steps to make the gated measurement MEASUREMENT PEAK VOLTAGE TRACKING PEAK AC DC OFFSET CURSOR J She BUBTAUBVAUAIBURTENE Se GROUND TRACKING CURSOR Figure 5 1 PEAK voltage measurement and tracking cursors 5 4 2246 1Y and 2246 Mod A Operators Basic Applications 1 Select GATED PEAK measurement mode The menu will be removed if configured to do so and any enabled tracking cursors will be displayed If none are enabled in page 2 of the CURSORS menu none will be displayed NOTE Only two of the possible three available selections may be dis played on a priority basis TRACK MEASMT has the highest priority followed by TRACK TRIG LVL and TRACK in that order Also the TRACK TRIG LVL cursors may only be displayed on the Trigger SOURCE signal The TRACK MEASMT cursor may be directed to either CH 1 or CH 2 input signal without regard to the trigger signal SOURCE 2 Adjust the B INTEN and A INTEN controls to provide a good viewing contrast of the intensified zone that appears on the A Sweep trace NOTE If the zone does not appear it may be positioned out of the viewing area but not past the end of the A Sweep trace Turn the OR DELAY control countercloc
32. dc offset NOTE It may be necessary to adjust the TRIGGER LEVEL control to ob tain a triggered display Set CH 1 input COUPLING to AC CHECK display amplitude is 4 2 division or more Set VERTICAL MODE to CH 2 CH 1 off Repeat the procedure for CH 2 Disconnect the test equipment from the 2246 1Y or 2246 Mod A 2246 1Y and 2246 Mod A Operators 7 25 Performance Check Procedure 23 24 cf vertical ALT and CHOP Modes Set VERTICAL MODE CH 1 CH 2 CH 3 CH 4 ALT CHOP off CH 1 and CH 2 VOLTS DIV 10 mV CH 3 and CH 4 VOLTS DIV 0 1 v CH 1 and CH 2 Input COUPLING DC Horizontal MODE A SEC DIV 1ms TRIGGER MODE AUTO LEVEL Position all traces for two divisions of separation with the CH 1 trace near the top then In order down the graticule area with the CH 4 trace near the bottom Set SEC DIV to 10 ms CHECK that four traces are sweeping across the screen alternately Set CHOP VERTICAL MODE On CHECK that four traces are sweeping across the screen simultaneously BEAM FIND Functional Check Push BEAM FIND in and hold CHECK the signal Is visible and compressed fully within the graticule area as the horizontal and vertical position controls are rotated through their ranges Release the BEAM FIND button Set all Vertical and Horizontal POSITION controls at the 12 o clock position 7 26 2246 1Y and 2246 Mod A Operators Performance Check Procedure 25 A and B Trace Separation a
33. display the correct vertical scale factors when properly coded probes are connected to the vertical input connectors The horizontal deflection system provides single dual or delayed sweeps from 0 5 s to 20 ns per division delayed sweep 5 ms to 20 ns per division The trigger system provides stable triggering over the full bandwidth of the vertical deflection system Alphanumeric crt readouts of the vertical and horizontal scale factors are displayed at the bottom of the screen On screen vertical and horizontal cursors provide accurate voltage time frequency and phase measure ments measurement values are displayed at the top of the crt The measurement features include voltage measurements for Peak Peak Peak to Peak and average DO or positionable cursors for measuring voltage difference time difference frequency and phase SmartCursors that visually track voltage measurements trigger levels and ground can be placed on displayed waveforms Delay time and delta delay measurements for time frequency and phase are available in ALT and B Horizontal Modes 1 2 2246 1Y and 2246 Mod A Operators Introduction Standard Accessories The following Items are standard accessories shipped with the 2246 1Y and 2246 Mod A instrument Probes 10X 2 meter with accessories Probe 1X 2 meter with accessories Power cord Power cord clamp CRT implosion shield blue plastic installed Fuse 2A 250 V slow blow Attaching
34. division Set the intensified dot to a positive peak of the displayed waveform CHECK the readout is between 47 0 mV and 53 0 mV Disconnect the test signal from the 2246 1 Y or 2246 Mod A 7 54 2246 1Y and 2246 Mod A Operators Performance Check Procedure EXTERNAL Z AXIS PROBE ADJUST AND FRONT PANEL SETUP FUNCTIONS Equipment Required See Table 7 1 Calibration generator Two 50 2 BNC coaxial cables 50 Precision BNC coaxial cable BNC T connector Test oscilloscope with a 10X probe Check External Z Axis Input Set READOUT Intensity A INTEN VERTICAL MODE CH 1 VOLTS DIV CH 2 INVERT SCOPE BW CH 1 Input COUPLING Horizontal MODE A SEC DIV A B SELECT TRIGGER MODE TRIGGER CPLG TRIGGER SOURCE TRIGGER SLOPE TRIGGER HOLDOFF MEASMN TS FOCUS Horizontal POSITION For a viewable readout For a viewable trace CH 1 Iv off off DC A 0 5 ms A Trigger AUTO LEVEL DC VERT positive going Min All off press CLEAR DISPLAY 3 times For best defined display 120 clock b Connect calibration generator PG 506 Std Ampl output to the CH 1 and the EXT Z AXIS inputs via a 50 precision BNC coaxial cable a BNC T connector and two 50 BNC coaxial cables Set generator to Std Ampl output 5 V C Set A INTEN to maximum intensity 2246 1Y and 2246 Mod A Operators REV AUG 1988 7 55 Performance Check Procedure d CHECK waveform display intensity starts decreasing at 1 8
35. operating mode features in the CONFIGURE menu seldom need to be changed A typical CONFIGURE menu is shown in Figure 3 9 Select CONFIGURE from the SERVICE MENU and answer YES or NO to each of the displayed questions For each answer YES or NO will be under lined to indicate how the instrument is presently configured The factory settings default is NO for all CONFIGURE questions After YES or NO is selected the next configuration choice is displayed After answering the last question the SERVICE MENU display returns To exit from the CON FIGURE menu without answering the remaining question s press the END button or the CLEAR DISPLAY button The CONFIGURE items are listed as follows KEEP MENU ON WHEN MEAS MT SELECTED Selecting NO clears the measurement menu items from the display after a measurement function is selected Measurement cursors remain displayed The AUTO TRACKING MENU remains on after a selection has been made Selecting YES allows a measurement menu to remain displayed after a function is selected The measurement menu Items can be removed at any time by pressing the CLEAR DISPLAY button once RECALL ONLY IN STORE RECALL This feature is not available on the 2246 1Y and 2246 Mod A However a selection must be made to continue through the CONFIGURE menu KEEP MENU ON WHEN S R SELECTED This feature is not available on the 2246 1Y and 2246 Mod A However a selection must be made to continue through the CONFIGUR
36. or if the menu is configured to remain on the display menu will remain on for making further choices until either MENU OFF is selected or the CLEAR DISPLAY button is pressed The service menu can be turned off by selecting QUIT from the menu or pressing the CLEAR DISPLAY button Clearing the Menu and Cursors Display The CLEAR DISPLAY button clears displayed menus turns off measure ment functions including TRACK MEASMT cursors and turns off the TRACK TRIG LVL and TRACK 77 cursors Depending on what menus and measurements are displayed at the time you may have to press the CLEAR DISPLAY button as many as three times to completely clear the display If a menu is on pressing the CLEAR DISPLAY will remove the menu and return the display to a normal operating mode Measurement functions are turned off with the second press or the first press if no menu is displayed Finally the TRACK TRIG LVL and TRACK m cursors are canceled with a third press or the first press if no menu is displayed and no measurement function is active 2246 1Y and 2246 Mod A Operators 3 5 Operators Familiarization Setting Measurement Channel Press SET MEAS MT CHANNEL button to call up one of two menus for setting the measurement channel s One menu is for voltmeter measure ments Figure 3 3 the other is a two page menu for delta time measure ments Figure 3 4 Each menu lists vertical input channels that can be selected for the active measurem
37. or the frequency Is below 10 Hz The set triggering level changes only when the TRIGGER LEVEL control is adjusted to a new level setting NORM Triggers the A sweep when the A Trigger LEVEL control is set within the peak to peak limits of an adequate trigger signal When the A sweep is not triggered no baseline trace is displayed TV LINE Starts the A sweep at the beginning of a video signal line SLOPE polarity must match the composite sync polarity i e _ 2246 1Y and 2246 Mod A Operators 2 13 Controls Connectors and Indicators SLOPE for positive sync to obtain TV LINE triggering on the hori zontal sync pulse TV FIELD Starts the A sweep at the beginning of a video signal field SLOPE polarity must match the composite sync polarity to obtain TV FIELD triggering SGL SEQ Single Sequence Sets up the A sweep for single sequence operation Each additional press of the down arrow MODE button when in single sequence mode resets the sweep and makes it ready to accept a trigger As in NORM trigger MODE the set trig gering level changes only when the TRIGGER LEVEL control is adjusted to a new level setting When triggered the sweep runs to produce a single sweep of each trace as required by the setting of the VERTICAL MODE and Hori ZONTAL MODE switches Each displayed sweep in the sequence requires a distinct A sweep triggering event The READY light remains on until the final trace in the sequence is completed The read
38. oscilloscope The TRACK TRIG LVL cursors provide both a visual indication of location and a numeric readout of the Trigger LEVEL control setting In ALT Horizontal MODE with the A Intensified and the B Delayed traces both displayed the A and the B TRACK TRIG LVL cursors will be displayed see Figure 5 10 The A Trigger LEVEL may be set when the trigger controls are directed to 2246 1Y and 2246 Mod A Operators 5 19 Basic Applications the A Trigger system by the A B SELECT switch and the B Trigger LEVEL may be set when the trigger controls are directed to the B Trigger system The Trigger LEVEL cursor will be displayed when enabled if the following conditions exist a The Trigger SOURCE is either CH 1 or CH 2 selected directly or with VERT SOURCE b The Trigger SOURCE channel is displayed QUESTION MARK A TRIGGER APPEARS WHEN LEVEL CURSOR B SWEEP IS NOT RUNS AFTER EVA WAC V TATANEN oa Se ele 15 a is S B TRIGGER LEVEL CURSOR Figure 5 10 A and B Track Trig Lvl cursors 5 20 2246 1Y and 2246 Mod A Operators Basic Applications c The Trigger CPLG is DC or NOISE REJ d The Trigger mode is AUTO LEVEL AUTO NORM RUNS AFTER or SGL SEG e TRACK MEASMT has not been selected or no measurements are active Additionally the A Trigger LEVEL cursor is displayed in A and ALT Hori zontal MODE and the B Trigger LEVEL cursor is displayed in ALT or B Horizontal MODE both displayed i
39. point 2246 1Y and 2246 Mod A Operators 3 1 Operators Familiarization MEASUREMENT NAME AND VALUE OR ERROR MESSAGE VOLTS DIV ote Gp ac Epes Sh oven ance Hig ce 4 i 2 gt gt s SEC DIV CH1 VOLTS DIV CH1 COUPLING CH2 VOLTS DIV OR X Y MODE SEC DIV BW 20 MHz UNCAL X10 CH2 COUPLING MAS SEC DIV UNCAL INPUT COUPLING SYMBOLS N GND 7 6558 10 Figure 3 1 Readout display locations 3 2 2246 1Y and 2246 Mod A Operators Operators Familiarization 1ST OR LEFT 11TH OR RIGHT VERTICAL VERTICAL GRATICULE LINE GRATICULE LINE RISE AND eee CENTER FALL TIME NE HORIZONTAL MEASUREMENT PERCENTAGE MARKERS CENTER VERTICAL GRATICULE LINE 6558 11 Figure 3 2 Graticule measurement markings Connecting Input Signals Grounding The most reliable signal measurements are made when the 2246 1Y or 2246 Mod A and the unit under test are connected by a common reference ground lead in addition to the single lead or probe The ground lead of the probe provides the best grounding method for signal interconnection and ensures the maximum amount of signal lead shielding in the probe cable A separate ground lead with a banana plug can also be connected from the unit under test to the 2246 1Y and 2246 Mod A ground jack on the front panel 2246 1Y and 2246 Mod A Operators 3 3 Operators _Familiarization Probes A probe pro
40. probe com pensation before making measurements 1 2 Perform Initial Setup procedure Connect the two supplied 10X probes to the CH 1 and CH 2 BNC input connectors Connect the probe tips to the PROBE ADJUST connector and the probe ground leads to scope ground Set CH 1 amp CH 2 COUPLING DC A SEC DIV 0 5 ms Set the CH 1 VOLTS DIV setting to 0 1 V 10 mV with probe discon nected and vertically center the PROBE ADJUST square wave signal Check the square wave signal for overshoot and rolloff see Figure 4 1 If necessary use the special adjustment tool supplied in the probe accessory package to adjust the low frequency compensation for a square front corner on the square wave displayed Press the CH 2 VERTICAL MODE button to turn CH 2 on in the display and press the CH 1 Mode button to remove the CH 1 trace from the display Set the CH 2 VOLTS DIV setting to 0 1 V 10 mV with probe discon nected and vertically center the PROBE ADJUST square wave signal Repeat Steps 5 and 6 for the second probe on the CH 2 BNC input connector 2246 1Y and 2246 Mod A Operators 4 3 Operator Checks and Adjustments CORRECT FLAT OVER COMPENSATED OVERSHOOT 7 UNDER COMPENSATED ROLLOFF 6558 15 Figure 4 1 Probe compensation NOTE Refer to the instruction manual supplied with the probe for more detailed information about the probes and
41. signal level 1 V Repe tition rate 1 MHz Rise time 1 ns or less Flatness 0 5 Marker outputs 5 ns to 0 5 s Marker accuracy 0 196 Trigger output 1 ms to 0 1 us time coincident with markers Item and Example of Description Test Equipment TEKTRONIX SG 503 Leveled Sine Wave Generator Leveled Sine Wave Generator Vertical hori zontal trigger ing measure ment bandwidth and Z Axis checks and adjustments Calibration Generator TEKTRONIX PG 506 Calibration Generator 2 Signal source for gain and transient re sponse checks and adjustments Time Mark Generator Horizontal checks TEKTRONIX and adjustments TG 501 Display adjust Time Mark ment Time Generator a cursor checks Function Generator Range less than 1 Hz to 100 kHz sinusoidal output amplitude variable up to greater than 10 V p p open circult with dc offset adjust TEKTRONIX FG 502 Function Generator Low frequency checks X Y phase check Requires a TM500 series power Module 2246 1Y and 2246 Mod A Operators 7 8 Performance Check Procedure Table 7 1 cont Item and Minimum Example of Description Specification Use Test Equipment Coaxial Cable impedance 50 Q Signal inter Tektronix Part 2 required Length 42 in connection Number Connectors BNC 01
42. to 5 10 3 92 to 4 08 2246 1Y and 2246 Mod A Operators REV AUG 1988 7 15 Performance Check Procedure 10 CH 3 and CH 4 Vertical Deflection Accuracy a Set VERTICAL MODE CH 3 CH 1 off CH 3 amp CH 4 VOLTS DIV 0 1 v Position the trace two graticule lines below the center graticule line Move CH 1 test setup to the CH 3 input Set calibration generator AMPLITUDE to 0 5 V CHECK the signal amplitude is between 4 90 and 5 10 divisions Move the test signal to the CH 4 input Set VERTICAL MODE to CH 4 CH 3 Off h Position the trace two graticule lines below the center graticule line Repeat CHECK for CH 4 Set CH 3 and CH 4 VOLTSIDIV to 0 5 V Set calibration generator AMPLITUDE to 2 V CHECK the signal amplitude Is between 3 92 and 4 08 divisions m Set VERTICAL MODE to CH 3 CH 4 off n 11 Move the test signal to the CH 3 input Repeat CHECK procedure for CH 3 Disconnect the test setup from the 22461 Y or 2246 Mod A ADD Mode and CH 2 INVERT Deflection Accuracy Set VERTICAL MODE ADD all others off CH 1 and CH 2 VOLTS DIV 0 1 v CH 1 and CH 2 Input COUPLING DC 7 16 2246 1Y and 2246 Mod A Operators Performance Check Procedure 12 Connect calibration generator STD AMPL output to the CH 1 and CH 2 inputs via 50 precision BNC coaxial cable and a BNC dual input coupler Set the calibration generator AMPLITUDE to 0 2 V Position the ADD signal to the center of the crt gr
43. 0 BNC termination For a viewable readout For a viewable trace CH 1 50 mV off off GND A 1ms A Trigger AUTO LEVEL DC VERT positive going Min DC For best defined display 12 o clock CHECK ground readout is 0 0 mV 1 2 mV Set calibration generator PG 506 internal Square Wave DC switch to 2246 1Y and 2246 Mod A Operators n Performance Check Procedure NOTE The PG 506 must be removed from the TM power supply to make the change to dc output from the generator Turn the power off before removing or inserting any plug in from the TM power supply Connect the calibration generator Std Ampl output to the CH 1 input via a 50 precision BNC coaxial cable Set calibration generator for Std Ampl output of 50 mV dc Set CH 1 VOLTS DIV 10 mV CH 1 Input COUPLING DC CHECK the readout is between 49 0 mV and 51 0 mV Set CH 1 VOLTS DIV to 0 1 V Set calibration generator for Std Ampl output 0 5 V CHECK the readout Is between 0 495 V and 0 505 V Set CH 1 VOLTS DIV to 1 V Set calibration generator for Std Ampl output of 5 V CHECK the readout is between 4 95 V and 5 05 V Disconnect Std Ampl signal from the CH 1 input DC Volts Normal Mode Rejection Ratio Set SEC DiV to 5 ms Connect function generator FG 502 output to the CH 1 input via a 50 BNC coaxial cable and BNC coupling capacitor Set function generator for a six division sine wave display amplitude at
44. 0 V 50 Hz 2 5 m 2246 1Y and 2246 Mod A Operators REV JUN 1989 8 1 Options and Accessories The The following additional standard accessories are Standard Accessories The following standard accessories are provided with both the 2246 1Y and 2246 Mod A 2 Probes 10X 2 meter with accessories 1 Probes 1X 2 meter with accessories Adapters probe tip Probe tips spring Power cord clamp oe WW CRT implosion shield blue plastic installed following additional standard accessories are 2 Operators manuals 2 Reference Guides 2 Service Manuals Mod A 8 2 1 Operators manual 1 Reference Guide REV JUN 1989 Attaching accessories pouch Accessory pouch ziploc Power cord Option 0 5 Protective front panel cover Fuse 2 A 250 V slow blow Part Number P6109 or equivalent P6101A or equivalent 103 0051 01 206 0060 00 016 0857 00 016 0537 00 As ordered 343 1213 00 200 3232 00 337 2775 00 159 0023 00 provided with the 2246 Part Number 070 7061 00 070 7062 00 070 7063 00 provided with the 2246 Part Number 070 7061 00 070 7063 00 2246 1Y and 2246 Mod A Operators Options and Accessories Optional Accessories The following optional accessories are recommended for use with the 2246 1Y or 2246 Mod A Instrument Enhancements Protective Front Panel Cover Attaching Accessories Pouch Protective Waterproof Vinyl Cover Clear Implosion Shield Rackmounting kit
45. 1 inch at 4 63 Hz 1 1 9 for 30 minutes on the bottom and 30 minutes on the side for a total of 60 minutes Meets the limits of the National Safe Transit Association test procedure 1A B 2 10 drops of 36 inches Packaged Vibration Test Package Drop Test RACKMOUNT INSTRUMENT Temperature Operating Inside Rack Cabinet Fan Exhaust Temperature 10 C to 55 C 15 minutes along each of 3 axes at a total displacement of 0 015 inch p p 2 3 g at 55 Hz with frequency varied from 10 Hz to 55 Hz in one minute sweeps Held 10 minutes at each major resonance or if none existed held 10 minutes at 55 Hz 75 minutes total test time Vibration at mounting points of Rack Adapter 30 g half sine 11 ms duration three shocks on each face for a total of 18 shocks Shock at mounting points of Rack Adapter operating and nonoperating 6 18 2246 1Y and 2246 Mod A Operators Mechanical Performance Characteristics Table 6 3 Characteristics CHARACTERISTICS DESCRIPTION STANDARD INSTRUMENT Weight With Front Cover Accessories and Accessories Pouch without manual With Power Cord Shipping Weight Domestic Overall Dimensions Height With Feet and Accessories Pouch empty Without Accessories Pouch Width with handle Depth With Front Cover on With Handle Extended Cooling Finish Construction 2246 1Y and 2246 Mod A
46. 1984 eingehalten werden TABLE OF CONTENTS Page LIST OF ILLUSTRATIONS 0 0 000000 e vi EIST OP TAB LEA um RR weak oh te held Gare ak BM des viii OPERATORS SAFETY SUMMARY ix SECTION 1 INTRODUCTION PRODUCT OVERVIEW LE nun eee e 1 1 Description es Sense ee ae Ge RAN ge 1 1 Standard Accessories 1 3 PREPARATION FOR USE 000002 ee 1 4 Sally est nae eed ea ee es ee we 1 4 AEE AE EE Sine aa rt Ur Car M iL ra d 1 4 Line Voltage and Power 1 4 Instrument 1 6 Start Ups ee e ets t nnne re arce FIERE 1 6 Repackaging for 5 1 7 SECTION 2 CONTROLS CONNECTORS AND INDICATORS CRT Power and 2 1 Vertical ER pn nt Rd RE 2 3 Horizontale e ESI RAE E ete put amb Gere eus rs 2 7 Trigger uri ait ate at ea e Ropa t e EU APER 2 11 A Trigger 2 13 B Trigger Modes ee Cot ne 2 14 Rear Panels cece ea eR RA ERU EA RU Ea 2 17 Menu System 2 19 SECTION 3 OPERATORS FAMILIARIZATION BASIC OPERATION ted ub Eta 3 1 Readout Display 2 4 rox RE een 3 1 Graticule Mr EE 3 1 2246 1Y and 2246 Mod A Operators Connecting Input
47. 1R 6 23 2246 1Y and 2246 Mod A Operators vii LIST OF TABLES Table Page 2 1 VERT Trigger SOURCE 22 2 16 3 1 Behavior for Horizontal MODE Changes 3 18 5 1 Trigger Cursor Channel 5 22 6 1 Electrical Characteristics 6 2 6 2 Environmental Characteristics 6 16 6 3 Mechanical Characteristics 6 19 7 1 Test Equipment Required nn nn nn 7 3 7 2 Signal to Graticule Accuracy 7 15 7 3 Settings for Timing Accuracy Checks 7 38 7 4 Delay Time Accuracy 7 42 A 1 Factory Settings c es A 1 viii 2246 1Y and 2246 Mod A Operators OPERATORS SAFETY SUMMARY The safety information in this summary is for operating personnel Warnings and cautions will also be found throughout the manual where they apply Terms in this Manual CAUTION statements identify conditions or practices that could result in damage to the equipment or other property WARNING statements identify conditions or practices that could result in personal injury or loss of life Terms as Marked on Equipment CAUTION indicates a personal injury hazard not immediately accessible as one reads the markings or a hazard to property including the equipment itself DANGER indicates a personal injury hazard immediately accessible as one reads the marking Symbols in this Manual cautionary or other information is to be found Fo
48. 2 0057 01 Precision Impedance 50 Used with PG Tektronix Part Coaxial Cable Length 36 in 506 Calibration Number Connectors BNC Generator and 012 0482 00 SG 503 Sine Wave Generator Termination Impedance 50 Signal termi Tektronix Part 2 required Connectors BNC nation Number 011 0049 01 10X Attenuator Ratio 10X Triggering Tektronix Part Impedance 50 checks Number Connectors BNC 011 0059 02 2X Attenuator Ratio 2X Triggering Tektronix Part Impedance 50 2 checks Number Connectors BNC 011 0069 02 Adapter Connectors BNC Signal inter Tektronix Part male to connection Number miniature probe 013 0084 02 tip Alignment Length 1 in shaft Adjust TRACE Tektronix Part Tool Bit size 3 32 in ROTATION pot Number Low capacitance Adjust variable 003 0675 00 insulated capacitors and resistors Test Bandwidth Z Axis Response TEKTRONIX Oscilloscope 20 MHz adjustment 2246A Dual Input Connectors BNC Signal inter Tektronix Part Coupler female to dual connection Number BNC male 067 0525 01 T Connector Connectors BNC Signal inter Tektronix Part connection Number 103 0030 00 Precision Input Resistance Input Capaci Tektronix Part Normalizer 1 Input tance adjust Number Capacitance ments 067 1129 00 20 pF 7 4 2246 1Y and 2246 Mod A Operators Performance Check Procedure Table 7 1 cont Minimum Specification
49. 2 2246 Y and 2246 Mod A Operators Controls Connectors and Indicators Vertical Refer to Figure 2 2 for location of items 10 through 17 CH 1 and CH 2 POSITION Controls Adjust vertical position of the Channel 1 and Channel 2 waveform displays 1 MODE Buttons Select the vertical channels for display CH 1 ADD channels 1 and 2 CH 2 CH 3 and CH 4 The CHOP ALT MODE button selects method for switching input channels on the display chopped or alternating Except for CHOP ALT modes pressing an unlit mode button turns on the mode and pressing a lit button turns off the mode CHOP is selected when the CHOP ALT button is lit ALT is selected when the button is not lit CH 1 CH 2 CH 3 and CH 4 Select vertical channels for display At least one of the channels or ADD is always on and cannot be turned off until another channel is first turned on CHOP ALT In the CHOP mode the display chops between selected input channels at a rate of about 625 kHz In the ALT mode the selected channels are displayed in sequence alternating at the end of each sweep ADD Displays the algebraic sum of the Channel 1 and Channel 2 input signals The ADD display is in addition to any other selected channel displays In the ADD mode a plus sign is displayed between the Channel 1 and Channel 2 VOLTS DIV readouts NOTE In ADD mode when AUTO LEVEL TRIGGER MODE or CHOP VERTICAL MODE is selected the algebraic sum of Channel 1 and Channel 2
50. 246 Mod A oscilloscope during calibration 2246 1Y and 2246 Mod A Operators B 1 MANUAL CHANGE INFORMATION At Tektronix we continually strive to keep up with latest electronic developments by adding circuit and component improvements to our instruments as soon as they are developed and tested Sometimes due to printing and shipping requirements we can t get these changes immediately into printed manuals Hence your manual may contain new change information on following pages A single change may affect several sections Since the change information sheets are carried in the manual until all changes are permanently entered some duplication may occur If no such change pages appear following this page your manual is correct as printed NOLLVINNYOANI 39NVHO Tektronix MANUAL CHANGE INFORMATION Up rie TEAS C5 1190 Date _11 26 90 Change Reference Product 2246 1Y and 2246 Mod A OPERATORS Manual Part Number DESCRIPTION Product Group 46 EFFECTIVE ALL SERIAL NUMBERS Page 7 28 Step 1 500 Hz Trigger Sensitivity Add the following setting to part a Scope BW On Page 7 29 Step 2 500 kHz Trigger Sensitivity Add the following setting to part a Scope BW off Page 7 32 Step 5 100 MHz NOISE REJ Trigger Sensitivity Replace step 5 entirely with the following procedure 100 MHz NOISE REJ Trigger Sensitivity Move test signal to the CH 1 input Set VERTICAL MODE to CH 1 others off Remove the 2X BNC attenua
51. 25 Hz to 10 MHz 2 0 of reading 10 of one vertical division 0 3 mV Gated Region Mini mum Width when gated 0 2 division 50 ns or fess PK PK VOLTS Accuracy Full Bandwidth 25 Hz to 25 MHz 2 0 of reading 15 of one vertical division 1 5 mV Greater Than 25 MHz to 100 MHz 0 5 dB 3 dB 1 5 mV Follows the 90 MHz at 35 C trigger system frequency response curve to 55 C Accuracy Bandwidth Limited 25 Hz to 10 MHz 2 0 of reading 10 of one vertical division 0 5 mV Gated Region Mini mum Width when gated 0 2 division 50 ns or less 6 10 2246 1Y and 2246 Mod A Operators Performance Characteristics Table 6 1 cent Electrical Characteristics CHARACTERISTICS CURSOR FUNCTIONS k SEC gt manually positioned cursors Accuracy 0 5 s div to 0 1 us div 50 ns div to 20 ns div k 1 SEC manually positioned cursors Accuracy k VOLTS manually positioned cursors Accuracy th VOLTS gt I manually positioned cursor Accuracy Ie PHASE manually positioned cursors Accuracy TRACK MEASUREMENT Position Accuracy Cursor position on waveform versus digitally displayed measurement value TRACK TRIG LEVEL Position Accuracy Cursor position on waveform versus digitally displayed trigger level value PERFORMANCE REQUIREMENTS 0 596 of reading 2 of the SEC DIV setting 1 2 of reading 2 of the SEC DIV setting
52. 50 Hz with CH 1 VOLTS DIV at 1 V Set CH 1 VOLTS DIV to 0 2 V 2246 1Y and 2246 Mod A Operators 7 51 Performance Check Procedure CHECK that the readout Is less than 0 010 V Disconnect the function generator signal from the 2246 1Y or 2246 Mod A Peak Peak Peak to Peak Volts Accuracy Set VERTICAL MODE CH 2 CH 1 off CH 2 VOLTS DIV 10mV CH 2 Input COUPLING DC CH1 CH2 VOLTMETER PEAK Set the calibration generator PG 506 internal Square Wave DC Switch for a square wave output signal NOTE It is necessary to remove the PG 506 from the TM power supply module to set the internal Square Wavel DC switch to square wave output Turn the power off before removing or inserting any plug in from the TM power supply Connect calibration generator Std Ampl output to the CH 2 input via a 50 Q precision BNC coaxial cable Set calibration generator for Std Ampl output of 50 mV dc CHECK that the readout is between 47 0 mV and 53 0 mV Set SCOPE BW on CHECK the readout is between 47 7 mV and 52 3 mV Set CH 2 INVERT On CH1 CH2 VOLTMETER PEAK CHECK the readout is between 47 7 mV and 52 3 mV Set SCOPE BW Off CHECK the readout Is between 47 0 mV and 53 0 mV 7 52 2246 1Y and 2246 Mod A Operators Performance Check Procedure Set CH1 CH2 VOLTMETER PK PK CH 2 INVERT off CHECK the readout Is between 46 5 mV and 53 5 mV Disconnect calibration generator 25 MHz Peak
53. CHANNEL menu is displayed changing the Horizontal MODE except between ALT and B clears the menu and turns off the active measurement mode LAST MEAS MT Recalls the last active measurement mode to the display and resets the measurement channel If the last active measurement mode is already displayed when the LAST MEAS MT button is pressed only the measurement channel is reset ser MENU MEASUREMENTS CLEAR MEASMT LAST VOLT DISPLAY CHANNEL MEAS MT METER CURSORS TIME MENU MEAS MT CURSORS 7061 04 Figure 2 7 Menu controls 2 20 2246 Y and 2246 Mod A Operators Controls Connectors and Indicators Measurement channel for VOLTMETER and VOLTS cursors measure ment modes is set to Channel 1 or Channel 2 when either is displayed alone otherwise it is set to Channel 1 Measurement channels for time measurements in ALT or B Horizontal mode are set to the lowest number displayed channel for the delay time and the next lowest number displayed channel for the delta delay time if more than one channel is displayed Both are set to the same channel when only one is displayed ADD is considered the highest numbered channel NOTE When the memory backup battery is dead or has just been rep aced the last measurement is initialized to SEC at power on The battery must be rep aced by a qualified service person 46 Measurement Select Buttons Calls up Measurement selection menus Measurements are selected from the list
54. CW A INTEN For a good viewing intensity Remove 10X and 2X BNC attenuators from the test signal path Increase leveled sine wave generator output level until a stably trig gered display is just obtainable Set TRIGGER LEVEL fully CW Set leveled sine wave generator output for a stable display if necessary Set CH 1 VOLTS DIV to 1 V CHECK that the CH 1 signal display amplitude is four divisions or more peak to peak Note that the signal is not triggered Disconnect the test setup from the 2246 1Y or 2246 Mod A 2246 1Y and 2246 Mod A Operators 7 33 Performance Check Procedure 8 TV Field Trigger Sensitivity a Set VERTICAL MODE CH 2 CH 1 off CH 2 VOLTS DIV 2V SEC DIV 0 2 ms TRIGGER SLOPE X negative going TRIGGER MODE TV FIELD TRIGGER LEVEL 12 o clock b Connect TV signal generator negative going sync pulse output to the CH 1 input via a 50 BNC cable C Set CH 2 VAR VOLTS DIV control for a 0 5 division composite sync signal d CHECK that a stable display is obtained e Set CH 2 INVERT On TRIGGER SLOPE 7 positive going CHECK that a stable display is obtained 9 TV Line Trigger Sensitivity a Set SEC DIV 20 us TRIGGER MODE TV LINE TRIGGER HOLDOFF For a single triggered display b CHECK that a stable display is obtained c Set CH 2 INVERT off TRIGGER SLOPE W negative going d CHECK that a stable display is obtained e Set CH 2 VAR VOLTS DIV to Detent Position cali
55. Configure Menu in the Service Menu Features part of this section The displayed readout is the value of the measurement at the instant it is displayed 2246 1 and 2246 Mod A Operators REV AUG 1988 3 19 Operators Familiarization GATED PEAK GATED PEAK and GATED PK PK measurements are not available during single sequence mode and will be canceled if active when SGL SEQ is selected B Trigger AUTO LEVEL acquisitions do not occur when the A Trigger MODE i SGL SEQ Service Menu Features Most of the items in the SERVICE MENU are for diagnostics trouble shooting and calibration However there are three menu selections that are also for operational use CONFIGURE SELF CAL MEASUREMENTS and MAKE FACTORY SETTINGS Press the top and bottom menu item Select buttons to display the SERVICE MENU as shown in Figure 3 8 SERVICE MENU DIAGNOSE CONF IGURE SELF CAL MEASUREMENTS INTERNAL SETTINGS MENU EXERCISER MENU Figure 3 8 Service Menu 3 20 2246 1Y and 2246 Mod A Operators Operators Familiarization Press the buttons opposite the displayed up and down arrows to move the displayed underline to the desired menu item of CONFIGURE SELF CAL MEASUREMENTS or INTERNAL SETTINGS MENU Press RUN or SELECT At any point in the CONFIGURE routine select END to return the display to the SERVICE MENU Select QUIT from the INTERNAL SETTINGS MENU or the main SERVICE MENU to return to the oscilloscope mode Configure Menu The
56. DE SOURCE CPLG SLOPE and LEVEL controls and Trigger lights TRIG D and READY to either the A or B Trigger system A when lit B when not lit Either A or B trigger can be selected for any Horizontal MODE how ever A B SELECT is preset to A when A Horizontal MODE is selected and B when ALT or B Horizontal MODE is selected No change occurs when switching from B to X Y Horizontal MODE SLOPE Button Selects the slope positive or negative going the trigger source signal that triggers either the A sweep or the B sweep Button lit positive going button not lit negative going HOLDOFF Control Varies holdoff time between the end of one A sweep and the start of the next A sweep 2246 1Y and 2246 Mod A Operators 2 17 Controls Connectors and Indicators Matin fF SLOPE r4 n ule A B SELECT A B AUTO AUTO NR LEVEL auto AM NORM NORM TV TV LINE LINE FROM A SOURCE SOURCE CPLG j C6 6558 07 Figure 2 5 Trigger controls and indicators The HOLDOFF control can increase the minimum holdoff time by at least 10 times Adjusting this control can Improve triggering stability of aperiodic signals i e complex digital waveforms LEVEL Control Sets the amplitude level on the trigger signal at which either the A or B sweep is triggered Adjusting the LEVEL control to either end of its range in the AUTO LEVEL trigger mode resets the limits of
57. DELAY control both cursors are positioned together Adjust the control for a reading of 800 0 us Check that the cursors are eight divisions apart Press the CLEAR DISPLAY button to remove the cursors from the display 2246 1Y and 2246 Mod A Operators 4 5 SECTION 5 BASIC APPLICATIONS 2246 1Y and 2246 Mod A Basic Applications Introduction The TEKTRONIX 2246 1Y and 2246 Mod A Oscilloscopes provide an ac curate and flexible measurement system After becoming familiar with the controls indicators menus and capabilities of the instrument you can develop convenient methods for making special measurements for your own applications The measurements given in this section are examples of typical applications that may assist in developing efficient techniques for your specific measurements A brief description of how the graticule markings are used in making measurements Is given In Section 3 of this manual When a procedure calls for Initial Setup refer to Section 4 Operator Checks And Adjustments Certain signals such as video or aperiodic sig nals non repeating and signals containing many unrelated frequency com ponents may require more trigger signal conditioning and or holdoff to ob tain the best display CH 1 CH 2 Voltmeter Measurements The CH 1 CH 2 Voltmeter measurements are continuous measurements of the DC PEAK PEAK or PK PK values of an applied signal The measurement value is displayed
58. E menu 2246 1Y and 2246 Mod A Operators 3 21 Operators Familiarization CONF IGURE KEEP MENU ON WHEN MEAS SELECTED YES NO RUNNING Figure 3 9 Configure Menu KEEP READOUT ON IN SGL SEQ Selecting NO will keep the readout off in Single Sequence Trigger Mode This mode is useful for single sequence waveform photography The readout is displayed briefly after the sequence is completed to expose the film then cleared to prevent overexposure Selecting YES keeps the readout on when in the Single Sequence Trigger Mode This mode lets you view any of the measurements that continue to be made during SGL SEQ trigger mode even if no waveform is being displayed The front panel control settings may also be made in SGL SEQ without having to select a different Trigger Mode to see the readouts as the controls are changed The measurement readout is especially useful for the Voltmeter measurements because the signal on the selected input channel is continually monitored GATED Voltmeter measurements are not per mitted in SGL SEQ Trigger MODE When the final question is answered the SERVICE MENU display returns 3 22 2246 1Y and 2246 Mod A Operators Operators Familiarization Self Cal Measurements This selection does a self characterization of the vertical channels 1 and 2 and the horizontal timing The SELF CAL MEASUREMENTS routine stores calibration constants that set the accuracy of the internal measurement system Voltage o
59. ER a greater than symbol gt will appear before the delay time readout The readout value displayed is the delay time between the A trig ger and the time a B trigger can be accepted by the trigger system A question mark will appear in front of the delay time readout for delay measurements when the DELAY time is set to 0 25 division or less from the beginning of the sweep lt SEC or e 1 SEC 9 Time Measurement is selected when in ALT or B Horizontal MODE and the B Trigger MODE is not RUNS AFTER the displayed error message is USE RUNS AFTER DELAY TRIG MODE If the oscilloscope in not triggered when a gated voltage measurement mode is selected the following error message is displayed LOW REP RATE STILL TRYING This can happen if the selected trigger channel has no trigger signal applied in NORM Trigger MODE or if the Trigger LEVEL control is not set to obtain a triggered display An improperly triggered display in either AUTO LEVEL or AUTO Trigger MODE will cause the measurement readout value to be unstable but no error message will be displayed Measurements in Single Sequence Mode The following measurements run continuously during SGL SEQ Trigger MODE DC PEAK PEAK PK PK ie VOLTS 3 77 VOLTS le SEC 1 SEC and PHASE 4 The readout and or cursors are displayed briefly during single sequence mode for making a photographic record or they may be configured to remain on see the discussion on
60. Figure 5 4 Voltage measurement 2246 1Y and 2246 Mod A Operators 5 9 Basic Applications Time Measurement Cursors Time measurement cursors may be used on any of the input waveforms only in the A Horizontal MODE Time measurements are also available in ALT and B Horizontal modes see Time Delay Measurement in this section The units of the time cursors may be selected to provide some automatic calculations for the user The units of the SEC cursors are time s ms ps and ns the 4 1 SEC cursors have units of frequency Hz KHz and MHz and the Kk PHASE cursor units are in degrees and Scaled to a 360 degree reference set by the user Time Difference Use the following procedure steps as a guideline in making time difference measurements using the k SEC I cursors As with the VOLTS gt l cursors the Jc OR DELAY control positions both cursors together and the control positions the independent cursor 1 Apply the signal to the input connector s 2 Set Vertical MODE As desired CH 1 and or CH 2 VOLTS DIV and POSITION So that entire signal is on screen Horizontal MODE A 3 Select a SEC DIV setting that provides the fewest number of cycles of the applied waveform necessary to display the measurement points of interest This is to improve the accuracy of cursor placement for the measurement 4 Press TIME button and select k SEC gt from menu NOTE The independent cursor cannot be positio
61. Frequency Reject Attenuates high frequency triggering signal components above 50 kHz HF REJ coupling is useful for providing a stable display of low frequency components of complex waveforms and eliminates high frequency interference from the trigger signal LF REJ Low Frequency Reject Attenuates low frequency trig gering signal components below 100 kHz and blocks the dc component of the trigger signal LF REJ coupling is useful for producing stable triggering on the high frequency components of complex waveforms and rejecting low frequency interference or power supply hum from the trigger signal AC Attenuates trigger signal frequency components below 50 Hz and blocks the dc component of the signal AC coupling is useful for triggering on ac waveforms that have a large dc offset Rear Panel Refer to Figure 2 6 for location of items 39 through 41 EXT Z AXIS INPUT Connector Connects external signals to the Z Axis amplifier for intensity modulating the crt display Signals applied to the EXT Z AXIS INPUT do not affect display waveshape Signals with fast rise times and fall times provide the 2246 1Y and 2246 Mod A Operators 2 17 Controls Connectors and Indicators most abrupt intensity change The active region threshold level is 1 8 V Z Axis voltage above the threshold voltage decreases the in tensity and 3 8 V or more produces noticable modulation The Z Axis signals must be time related to the displayed sign
62. H 1 VOLTS DIV 0 5 V use 0 2 V for the 5 ns time markers if necessary Align the rising edge of a time marker with the second vertical graticule line center the display vertically CHECK that the rising edge of the fourth displayed time marker to the right of the one positioned in step c crosses the center horizontal graticule line at between 8 27 divisions to 8 73 divisions Set SEC DIV to 5 ns Align a time marker to the second vertical graticule line CHECK that the tenth displayed time marker is within 0 24 division left or right of the tenth graticule line Repeat the timing and linearity checks for all SEC DIV settings between 10 ns and 0 5 s Use the SEC DIV and Time Mark Generator X10 MAG settings given in Table 7 3 Set Horizontal MODE A SEC DIV 2 ns with X10 MAG on Set time mark generator for 5 ns time marks Repeat the magnified accuracy and linearity for the A Sweep at all SEC DIV settings 7 40 2246 1Y and 2246 Mod A Operators N Ld Performance Check Procedure Delay Time Jitter Set X10 MAG off A SEC DIV 1ms Horizontal MODE ALT SEC DIV 0 5 ns Set time mark generator for 1 ms time marks Position the Intensified dot to the leading edge of the 10th time marker to display the rising edge on the B Trace using the jc OR DELAY control Set Horizontal MODE B B INTEN Fully CW maximum intensity CHECK that the jitter on the leading edge does not exceed one division over a two se
63. IV Settings 0 5 pF Maximum Input 400 V dc peak ac 800 V p p at 10 kHz Volts A or less 10 V dc peak ac at 1 MHz or less 5 V dc peak ac at 100 MHz or less VERTICAL DEFLECTION SYSTEM CH 3 AND CH 4 Deflection Factor Range 0 1 V per division and 0 5 V per division Accuracy 15 C to 35 C Within 296 10 C to 55 C Within 3 Frequency Response De to 100 MHz at the input BNC and with a 3 dB bandwidth 10X probe Step Response 5 division step Rise Time 3 5 ns or less calculated Delay Match CH 3 to CH 4 Less than 400 ps difference Trace Shift Between 1 division or less VOLTS DIV Settings Performance Requirement not checked in manual 6 4 2246 1Y and 2246 Mod A Operators Performance Characteristics Table 6 1 cent Electrical Characteristics CHARACTERISTICS Channel Isolation attenuation of deselected channel Input Characteristics Resistance Capacitance Maximum Input Volts A PERFORMANCE REQUIREMENTS 34 dB or more at 100 MHz Channel isolation tested with eight division input signal 1MQ 2 0 4 20 pF 2 400 V dc peak ac 800 V p p at 10 kHz or less 10 V dc peak ac at 1 MHz or less 5 V dc peak ac at 100 MHz or less VERTICAL DEFLECTION SYSTEM ALL CHANNELS Bandwidth Limit 3 dB bandwidth Low Frequency Linearity Relative to center screen Position Range TRACE SEP Control Position Range CHOP Mode Clock Rate Del
64. MHz NOISE REJ Trigger Sensitivity Move test signal to the CH 1 input Set VERTICAL MODE to CH 1 others off Remove the 2X BNC attenuator from the test signal path Set leveled sine wave generator output for a 2 2 division display ampli tude at 100 MHz CHECK that the display is stably triggered with NOISE REJ Trigger CPLG but Is not triggered with HF REJ Trigger CPLG Set TRIGGER CPLG DC Horizontal MODE B A B SELECT B Trigger Repeat 100 MHz NOISE REJ Trigger CPLG procedure for the B Trigger Single Sweep Mode Set Horizontal MODE A A SEC DIV 10 us A B SELECT A Trigger Remove the 10X and 2X BNC attenuators from the test signal path Set leveled sine wave generator output to produce a 7 0 division dis play amplitude at 50 kHz 7 32 2246 1Y and 2246 Mod A Operators N Performance Check Procedure Add a 10X and a 2X BNC attenuator before the 50 Q BNC termination Display should stably trigger with AUTO LEVEL finding the correct trigger level setting Set A TRIGGER MODE NORM CH 1 Input COUPLING GND TRIGGER MODE SGL SEQ CHECK that the Trigger READY LED turns on and remains on Set A INTEN 3 4 fully CW CH 1 Input COUPLING DC see CHECK below CHECK that the TRIG D LED flashes and the READY LED turns off after a single sweep and readout display occurs when the Input COUPLING switches to DC Trigger LEVEL Control Range Set TRIGGER MODE AUTO not AUTO LEVEL TRIGGER LEVEL Fully C
65. MODE CH 1 CH 4 off CH 1 VOLTS DIV 5 mV CH 1 COUPLING DC A SEC DIV 20 ns Connect calibration generator PG 506 FAST RISE _ output to the CH 1 input via a 10X 50 attenuator 50 precision BNC coaxial cable and 50 BNC termination Position top of waveform to 100 6 graticule marking Adjust calibration generator PULSE AMPLITUDE for five divisions of signal display CHECK that aberrations are lt 0 25 division peak to peak Repeat steps c through e for VOLTS DIV settings of 10 mV through 0 2 V Remove the 10X 50 0 attenuator when necessary to maintain a five division display Repeat the procedure for CH 2 Disconnect the test setup SCOPE BW Bandwidth Limit Accuracy Set VERTICAL MODE CH 1 CH 2 off CH 1 VOLTS DIV 10 mV SCOPE BW On A SEC DIV 0 1 ms Connect the leveled sine wave generator SG 503 to the CH 1 input via 50 precision BNC coaxial cable and 50 0 termination Set leveled sine wave generator SG 503 output for a six division signal amplitude at 50 kHz Set the leveled sine wave generator Frequency Range and Frequency Variable controls to produce a signal display amplitude of 4 2 divisions CHECK that the sine wave generator output frequency is between 17 MHz and 23 MHz Disconnect the test setup 7 22 2246 1Y and 2246 Mod A Operators 20 Performance Check Procedure Common mode Rejection Ratio Connect the leveled sine wave generator SG 503 output to the CH 1
66. MT TRACK TRIG LVL and TRACK 7r may be underlined but they cannot all be displayed at the same time Only two cursors at a time are permitted If enabled but not displayed in a particular waveform omitted cursors will be displayed when a higher priority cursor is turned off TRACK MEASMT cursors take priority over the TRACK TRIG LVL cursors TRACK TRIG LVL cursors take priority over TRACK th cursors The cursors dis played when a CURSOR VOLTS measurement is active take priority over all the Auto Tracking Cursors NOTE The CLEAR DISPLAY button will turn off the TRACK TRIG LVL and TRACK fh cursors if pressed the appropriate number of times To enable either or both of these it is necessary to re enter the Cursor Volts menu and reselect them The TRACK MEASMT cursors are also turned off by the CLEAR DISPLAY button but the function is not turned off the TRACK MEASMT cursor s will be displayed again when a CH 1 CH 2 Voltmeter measurement is called up 5 22 2246 1Y and 2246 Mod A Operators Basic Applications Setting Trigger Level The trigger level readout supplied by the TRACK TRIG LVL cursor may be used to set a specific trigger level for triggering on a displayed waveform As an example assume the following conditions a The signal to be examined is a mix of two different signal levels see Figure 5 1 1 b It is necessary to trigger on the larger amplitude signals to make a closer examination of their waveshape and take
67. OTE The reference and delta cursors will only track together as long as the reference delay plus the delta delay is less than 10 times the A SEC DIV setting 10 horizontal graticule divisions The cursors cannot be positioned left of the 1st or right of the 11th vertical graticule lines k OR DELAY This control has the following functions 1 Positions the reference and delta cursors together in a cursor measurement mode volts or time A Horizontal MODE 2 Positions the reference and delta delay together in the TIME measurement mode in the ALT or B Horizontal MODE 2246 Y and 2246 Mod A Operators Controls Connectors and Indicators 3 Sets the B sweep delay time in the ALT or B Horizontal Mode in DELAY measurement mode 4 Positions the intensified zone for GATED VOLTMETER measurements gt This control has the following functions 1 Positions the delta cursor in the cursor measurement mode 2 Sets the B sweep delta delay in TIME measurement mode when in the ALT or B Horizontal Mode 3 Sets the width of the intensified zone for GATED VOLTMETER measurements UNCAL Indicator Lights when the A AND B SEC DIV settings are uncalibrated variable function in effect G TRACE SEP Control Positions the B sweep trace vertically with respect to the A sweep trace when ALT Horizontal MODE is selected Trigger Refer to Figure 2 5 for location of items 32 through 38 32 A B SELECT Button Directs the MO
68. Operators 8 9 kg 19 5 Ib 7 9 kg 17 3 Ib 11 7 kg 25 8 Ib See Figure 6 2 Dimensional drawing Approx 176 5 mm 6 95 in 164 mm 6 44 in 362 mm 14 25 in 445 3 mm 17 53 in 521 mm 20 53 in Forced air circulation no air filter Tek Blue pebble grain finish painted on aluminum cabinet Aluminum alloy chassis Plastic laminate front panel Performance Characteristics Table 6 3 cent Mechanical Characteristics CHARACTERISTICS DESCRIPTION RACKMOUNT INSTRUMENT Weight With Power Cord Shipping Weight Domestic includes manual Overall Dimensions Height Overall Center of mounting rail to bottom of cabinet From cabinet top or bottom to respective front panel mounting holes Between front panel mounting holes Width Overall Between mounting hole centers Between outer edges of mounting rails Between handle centers 6 20 10 0 kg 22 0 Ib 14 2 kg 31 3 Ib See Figure 6 3 Dimensional drawing 168 mm 6 6 in 89 mm 3 5 in 38 mm 1 5 in 102 mm 4 0 in 483 mm 19 0 in 464 mm 18 3 in 427 mm 16 8 in 450 mm 17 7 in 2246 1Y and 2246 Mod A Operators Performance Characteristics Table 6 3 cent Mechanical Characteristics CHARACTERISTICS DESCRIPTION Depth Overall 516 mm 20 35 in Front panel to rear of mounting 465 mm 18 3 in rail inside Front panel to 472 mm 18 6 in rear of mounting rall outs
69. STORE RECALL SETUPS ADJUST VERTICAL OUTPUT Figure 3 10 Internal settings menu 3 24 2246 1Y and 2246 Mod A Operators SECTION 4 OPERATOR CHECKS AND ADJUSTMENTS 2246 1Y and 2246 Mod A Operator Checks and Adjustments Introduction The checks and adjustments in this section are for the operator and involve using only controls and adjustments on the outside of the instrument in ternal adjustments must be made by a qualified service person Before operating the instrument for the first time and before connecting the power refer to Section 1 Preparation for Use to prepare the instrument for the initial start up Verify that the POWER switch is OFF out position Plug the power cord into a power source outlet that supplies a voltage within the operating range of the instrument s power supply NOTE If you notice an improper indication or instrument malfunction during these procedures refer the instrument to a qualified serv ice person Initial Setup The following procedure may be used to set up front panel controls when the instrument is first turned on or when a signal is not being applied to the input connectors 1 Press in the POWER switch button ON and let the instrument warm up 20 minutes is recommended for maximum accuracy 2 Set the Instrument front panel controls to obtain a baseline trace Vertical Controls VERTICAL MODE CH 1 POSITION Center the trace VOLTS DIV 1V VOLTS DIV VAR Cal
70. Set CH 2 Input COUPLING to DC c CHECK trace shift does not exceed 0 25 division d Set VERTICAL MODE CH 1 CH 2 off CH 1 Input COUPLING GND e Position trace to center graticule line f Set CH 1 Input COUPLING to DC g CHECK trace shift does not exceed 0 25 division 6 CH 2 INVERT Trace Shift a Set VERTICAL MODE to CH 2 CH 1 off CH 2 Input Coupling GND b Position trace to center horizontal graticule line c Set CH 2 INVERT On d CHECK trace shift does not exceed one division e Set CH 2 INVERT off CH 2 COUPLING DC 7 CH 1 and CH 2 VAR VOLTS DIV Range a Set VERTICAL MODE to CH 1 b Position CH 1 trace to the center horizontal graticule line c Connect calibration generator PG 506 STD AMPL output to the CH 1 input via 50 precision BNC coaxial cable Set calibration generator to STD AMPL and AMPLITUDE to 50 mV 2246 1Y and 2246 Mod A Operators 7 13 Performance Check Procedure d Set CH 1 VOLTS DIV 10 mV CH 1 VAR VOLTS DIV Fully CCW e CHECK the signal amplitude Is two divisions or less f Set CH 1 VAR VOLTS DIV Detent calibrated VERTICAL MODE CH 2 CH 1 off CH 2 VOLTS DIV 10 mV g Position the CH 2 trace to the center horizontal graticule line h Move the test signal to the CH 2 Input 1 Set CH 2 VAR VOLTS DIV fully CCW 1 Repeat the CHECK procedure for CH 2 Set 2 VAR VOLTS DIV to detent calibrated position 8 Low Frequency Linearity Check a Set
71. V or less m e and the waveform is extremely modulated at 3 8 V Set A INTEN to midrange Disconnect the test equipment from the 22461 Y or 2246 Mod A PROBE ADJUST Output Set CH 1 VERTICAL MODE 10 mV SEC DIV 0 2 ms SCOPE BW On Connect a 10X probe to the CH 1 input connector and connect the probe tip to the 22461 Y or 2246 Mod A PROBE ADJUST output When using Tektronix coded probes the readout changes to 1 V CHECK For a 5 division vertical display of PROBE ADJUST square wave signal square wave period Is typically 1 ms within 25 Run MAKE FACTORY SETTINGS Routine a Press the top and bottom Menu Select buttons to display the SERVICE MENU Press the down arrow menu button three times and press SELECT to display the INTERNAL SETTINGS MENU Press the down arrow menu button once and press RUN to run the MAKE FACTORY SETTINGS routine When the routine Is finished press the CLEAR DISPLAY button to return to the normal oscilloscope mode THIS COMPLETES THE PERFORMANCE CHECK PROCEDURE 7 56 REV AUG 1988 2246 1Y and 2246 Mod A Operators SECTION 8 OPTIONS AND ACCESSORIES 2246 1Y and 2246 Mod A Options and Accessories OPTIONS AND ACCESSORIES Introduction This section lists the instrument options and accessories that were available at the time this manual was published To obtain additional information about these and other options and accessories refer to a current Tektronix Product Catal
72. a source of A and B trigger signals When you need a trigger signal source different from the one derived from displayed signals you can use any free vertical input channel CH 1 and CH 2 can condition a wide range of signals to produce triggers over the full vertical deflection range from millivolts to hundreds of volts CH 3 and CH 4 have two basic attenuation factors 0 1 and 0 5 volts division making them especially useful for triggering on and viewing digital signal levels 3 4 2246 1Y and 2246 Mod A Operators Operators Familiarization MENU SYSTEM OPERATION This subsection provides operating details of the measurement menus and Service menus Introduction Pressing one of the menu call up buttons causes a list of menu items to be displayed on the right hand side of the CRT beside a group of six Menu item Select buttons Pressing the menu button next to a menu item on the dis play selects that function i e to another menu page a measurement selection a measurement source channel service feature or menu off When a measurement mode measurement source channel or service feature in the menu list is selected that label is underlined Normally the menu display turns off after a measurement function is selected if not configured to remain on and the name and value of a Selected measurement function appears in the top line of the CRT readout However when it is possible to make more that one selection from the menu list
73. accessory pouch Accessory pouch ziploc Front Cover oa oa 2l 2l ll 4 The following Items are standard accessories shipped with the 2246 1Y instrument 2 Operators manuals 2 Service manuals 2 Reference guides The following Items are standard accessories shipped with the 2246 Mod A instrument 1 Operators manual 1 Reference guide See Section 8 Options and Accessories for part numbers and further information about standard accessories and a list of the recommended optional accessories For more information on accessories and ordering assistance contact your Tektronix representative or local Tektronix Field Office 2246 1Y and 2246 Mod A Operators REV JUN 1989 1 3 Introduction PREPARATION FOR USE Safety Refer to the Operators Safety Summary at the front of this manual for power source grounding and other safety information about the use of the instrument Before connecting the 2246 1Y and 2246 Mod A to a power source read this section and the Safety Summary Line Fuse This instrument can be damaged if the wrong line fuse is installed Verify the proper value of the power input fuse with the following procedure 1 Press in the fuse holder cap and release it with a slight counter clockwise rotation 2 Pull the cap with the attached fuse inside out of the fuse holder 3 Verify proper fuse value 4 Install the proper fuse and reinstall the fuse holder cap Line Voltage and Power Cord
74. al Electrical Manufacturer s Association SEV Schweizervischer Elektrotechnischer Verein UL Underwriters Laboratories Inc Figure 1 2 Optional power cords 2246 1Y and 2246 Mod A Operators 1 5 Introduction The detachable three wire power cord has a three contact plug for con nection to the power source and the protective ground The power cord is held to the rear panel by a clamp The protective ground contact on the plug connects through the power cord protective ground conductor to the accessible metal parts of the instrument Instrument Cooling To prevent instrument damage from overheated components make sure the internal airflow is not blocked Before turning on the power check that the ventilation holes on the bottom and side of the cabinet are not covered Start up At power on the instrument does a self diagnostic check If the instrument does not turn on and operate normally turn power off then on again If the instrument still does not turn on properly refer the instrument to a qualified service person TRIGGER MODE LEDs may be flashing to indicate the cir cuit location of a start up error you should report this information to the Service person When the instrument is turned on a self cal routine may run to set the voltage and timing measurement constants The power on self cal runs only if the stored constants have been lost possibly due to a dead memory back up battery The following warning message will b
75. al is received after the delay time condition has been met When there is no trigger signal there is no B sweep trace TV LINE FROM A SOURCE Starts the B sweep at the beginning of the video signal line received after the delay time has been met NOTE SLOPE polarity must match the composite sync polarity same as A Trigger SLOPE to obtain correct triggering on the horizontal sync pulse 37 source Up Arrow and Down Arrow Buttons and Indicators Select the trigger source for either the A or the B Trig ger system as directed by the A B SELECT button Pressing the Up Down Arrow SOURCE buttons selects the trigger source for A or B trigger system as shown by SOURCE lights VERT Selects the trigger signal from the displayed waveforms The TRIGGER MODE and VERTICAL MODE switch settings determine the trigger signal source selection When VERT is selected one or more of the SOURCE lights will be on to indicate the trigger signal source See Table 2 1 for VERT Trigger SOURCE selections CH 1 The signal applied to the CH 1 OR X input connector is the source of the trigger signal 2246 1Y and 2246 Mod A Operators 2 15 Controls Connectors and Indicators Table 2 1 VERT Trigger SOURCE Trigger and Vertical Modes Trigger Source Selected Algebraic sum of CH 1 and CH 2 input LEVEL signals or CHOP Lowest numbered vertical channel displayed Alternates between displayed vertical channels in
76. al to obtain a fixed intensity modulated crt display 40 Fuse Holder Contains the primary power fuse 4 Power Cord Receptacle Connects the ac power source to the instrument power supply CAUTION TO AVOID ELECTRIC SHOCK THE POWER CORO PROTECTIVE GROUNDING CONDUCTOR MUST CONNECTED TO GROUND DO NOT REMOVE COVERS REFER SERVICING TO QUALIFILD PERSONNEL DISCONNECT INPU POWER BEFORE REPLACING FUSE FOR CONTINUED FIRE PROTECTION REPLACE ONLY WITH SPECIFIED TYPE AND RATED FUSE 10 REMOVE POWER CORD DISCONNEC PLUG AND MAX VA 155 ROTATE RETAINER CLIP 99 FREQUENCY 4B 440H far 2 Ax S INPUT DECREASES INTENSITY 248v BIANAS AY Aus SWEEP THIS INSTRUMENT MAY PROTECTED BY OWE DR MORE US GA FOREICN UNE VOIPAGE RANGE PATENTS OR PATENT APPLICATIONS 30 50v Ac INFORMATION PROVIDED ON REQUEST ruft 250v i ipf SLOW TEKI ONIX ING BEAVERTON OREGON LSA 6558 08 Figure 2 6 Rear panel 2 18 2246 Y and 2246 Mod A Operators Controls Connectors and indicators The power cord protective ground connection is connected to the exposed metal parts of the instrument The power cord must be con nected to a properly grounded source for electrical shock protection Menu System Controls Refer to Figure 2 7 for location of items 42 through 46 42 Menu Item Select Buttons Select items from the list displayed on the right side of a displayed menu A Menu Item Select button that h
77. arization VOLTMETER DC PEAK PEAK PK PK SELF CAL TO GATED MEASMT MENU VOLTS PG 2 PEAK PEAK PK PK BACK TO PREVIOUS MENU Figure 3 5 Voltmeter and Gated Measmt menus 2246 1Y and 2246 Mod A Operators 3 9 Operators Familiarization Voltmeter Measurements Page 1 DC Measures the average DC level of the measurement channel waveform PEAK Measures the most positive screen relative voltage in the applied waveform PEAK Measures the most negative screen relative voltage in the applied waveform PK PK Measures the peak to peak voltage of the applied waveform SELF CAL Self characterizes the vertical system SELF CAL may be performed at any time Suggested times are after a warmup period whenever the ambient operating temperature changes by 15 C and just prior to making any voltmeter measurements requiring the best possible accuracy TO GATED MEASMT MENU Selects the gated measurement menu Voltmeter Measurements Page 2 GATED Measurements The oscilloscope must be properly triggered for gated measurements If there is no trigger signal in NORM Trigger MODE the message LOW REP RATE STILL TRYING will be displayed If there is no trigger signal in AUTO LEVEL or AUTO Trigger MODE the readout value will be unstable and meaningless Gated Voltmeter measurements are made within the gated intensified region on the displayed waveform The position of the gated zone Is set using t
78. as no corresponding menu item does nothing when pressed The menu display will clear when the item Is selected unless the SERVICE mode CONFIGURE menu is set for KEEP MENU ON WHEN ITEM SELECTED YES The factory settings default is NO You can access the Service Mode by pressing the top and bottom Menu ltem Select buttons at the same time See Service Menu Features in Section 3 for using the operational modes of the SERVICE MENU 43 CLEAR DISPLAY Clears displayed menus measurement functions and cursor functions in the following order 1 Menu display Service and Measurement menus 2 Measurement function including TRACK MEASMT cursors if displayed 3 TRACK TRIG LVL and TRACK 7 GASET MEAS MT CHANNEL Calls up menus for setting measurement source channels for active measurement modes There are two menus available one for voltmeter measurements and a two page menu for delay and delta time measurements Each menu lists input channels that can be selected for the active measure ment mode If the SET MEAS MT CHANNEL button is pressed for an invalid mode one of the following messages will be displayed for two seconds 1 SELECT A MEASUREMENT When no measurement mode is active 2246 1Y and 2246 Mod A Operators 2 19 Controls Connectors and Indicators 2 NO MEAS CHANNEL NEEDED When a selected measure ment mode such as cursor time does not require a measure ment channel to be set When a SET MEAS MT
79. aticule e Press TIME button to display the TIME menu 2246 1Y and 2246 Mod A Operators 7 45 Performance Check Procedure Press SEC 9 menu button to turn on time cursors g Position the reference cursor to the second time marker and the delta cursor to the tenth time marker h CHECK that the readout is 7 940 ms to 8 060 ms Press the TIME button to display the TIME menu Set t 1 SEC on k CHECK that the readout Is 124 Hz 126 Hz 2 Delta Time Accuracy a Set A TIME DIV to 1 us b Set the time mark generator for 1 us time markers c Position the trace to the upper portion of the crt display and align the time markers horizontally with the graticule d Set Horizontal MODE ALT B TIME DIV 50 ns B TRIGGER MODE RUNS AFTER l SEC 3 On e Center the first intensified zone over the time marker corresponding to the second graticule line and the second intensified zone over the time marker corresponding to the tenth graticule line Position the B sweep display to the lower portion of the crt using the TRACE SEP control and use the 9 control to align the delayed sweep so that the selected time markers overlap each other exactly g CHECK that the readout is between 7 910 us and 8 090 us 7 46 2246 1Y and 2246 Mod A Operators Performance Check Procedure 3 Je PHASE 4 Cursor Accuracy a Set generator for 1 ms time marks b Set Horizontal MODE A A TIME DIV 1ms c Set TIME menu on d P
80. aticule line by the reference waveform as shown in Figure 5 8A Select e PHASE 4 to continue with the phase measurement the reference value will then be saved Apply the phase shifted sine wave signal to be measured to the CH 2 Input connector using a 10X attenuator probe and turn CH 2 VERTICAL MODE on to display the signal Set the VOLTS DIV and VOLTS DIV VAR controls to match the ampli tude of the phase shifted signal to that of the reference waveform as shown in Figure 5 8B Use the VERTICAL POSITION control as necessary to align the two waveforms vertically Reposition the second cursor to the first positive crossing of the phase shifted signal and read the phase difference NOTE For increased resolution of the phase measurement the sweep many be increased and both cursors repositioned to the measure ment points see Figure 5 8 C The MAG feature may also be used in a similar manner by placing the measurement points at the center vertical graticule line before pressing the X10 MAG button you may want to reduce the A SEC DIV setting prior to turning on the X10 MA G feature 2246 1Y and 2246 Mod A Operators 5 15 Basic Applications BI Figure 5 8 Making a phase difference measurement 5 16 2246 1Y and 2246 Mod A Operators Basic Applications Time Delay Measurement When using ALT Horizontal Mode the TIME measurement mo
81. aticule with the CH 1 and CH 2 POSITION controls CHECK that the ADD signal amplitude is between 3 92 and 4 08 divisions Set CH 2 INVERT On CHECK the ADD signal amplitude is 0 08 division less than half a minor graticule division or less excluding trace width sweep will free run Disconnect the test setup from the 2246 1Y or 2246 Mod A Vertical POSITION Range all channels Set A SEC DIV 0 1 ms CH 1 VERTICAL MODE On ADD off CH 1 VOLTS DIV CH 2 INVERT off SCOPE BW off CH 1 and CH 2 Input COUPLING AC Connect the leveled sine wave generator SG 503 output to the CH 1 and CH 2 inputs via a 50 BNC coaxial cable a 50 BNC termina tion and a BNC dual input coupler Position trace to center horizontal graticule line Set leveled sine wave generator output for two division signal at 50 kHz Set CH 1 VOLTS DIV 0 1 v CH 1 POSITION Fully CW 2246 1Y and 2246 Mod A Operators 7 17 Performance Check Procedure f CHECK that the bottom of the waveform Is above the center horizon tal graticule line g Set CH 1 POSITION fully CCW h CHECK that the top of the waveform is below the center horizontal graticule line i Set CH 1 POSITION 12 o clock VERTICAL MODE CH 2 CH 1 off CH 2 POSITION Fully CW j CHECK that the bottom of the waveform is above the center horizon tal graticule line k Set CH 2 POSITION fully CCW 1 CHECK that the top of the waveform is below the cen
82. ay Match CH 1 or CH 2 to CH 3 or CH 4 20 MHz 25 Within 596 Linearity is measured by positioning a two division test signal anywhere on screen and noting the amplitude change At least 10 divisions from graticule center At least t 4 divisions 625 kHz 10 3 Less than 800 ps difference a Performance Requirement not checked in manual 2246 1Y and 2246 Mod A Operators 6 5 Performance Characteristics Table 6 1 cent Electrical Characteristics CHARACTERISTICS PERFORMANCE REQUIREMENTS HORIZONTAL DEFLECTION SYSTEM Sweep Range A Sweep 0 5 s div to 20 ns div in a 1 2 5 sequence 2 X10 magnifier extends maximum sweep speed to 2 ns div B Sweep 5 0 ms div to 20 ns div in a 1 2 5 sequence X10 magnifier extends maximum sweep speed to 2 ns div Accuracy Unmagnified Magnified 15 C to 35 C 2 3 10 C to 15 3 4 and 35 C to 55 C Sweep Accuracy applies over the center eight divisions Excludes the first 1 4 division or 25 ns from the start of the magnified sweep and anything beyond the 100th magnified division Sweep Linearity 5 Sweep Linearity applies over the center eight divisions of an unmagnified sweep Excludes the first 1 4 division or 25 ns from the start of the sweep Sweep linearity is determined by the error of a single time mark relative to two adjacent time marks spaced at one time mark per division pertormance Requirement not checked in manual 6
83. brated Disconnect the TV signal generator from the 2246 1Y or 2246 Mod A 7 34 2246 1Y and 2246 Mod A Operators Performance Check Procedure 10 Line Trigger Functional Check a Set CH 2 VOLTS DIV 0 1 V without a 10X probe attached CH 2 Input COUPLING DC A SEC DIV 5 ms TRIGGER MODE AUTO LEVEL TRIGGER SOURCE LINE TRIGGER CPLG DC b Connect a 10X probe to the CH 2 input connector c Attach the probe tip to a length of wire at least 4 in long Hold the wire near the instrument power cord d CHECK that the display can be triggered in both positive going and X negative going slopes e Disconnect the test setup 2246 1Y and 2246 Mod A Operators 7 35 Performance Check Procedure HORIZONTAL Equipment Required See Table 7 1 Time mark generator 50 BNC termination 50 Q BNC coaxial cable 1 A and B Sweep Length a Set READOUT intensity A INTEN VERTICAL MODE CH 1 and CH 2 Input COUPLING CH 1 VOLTS DIV Horizontal MODE A SEC DIV Horizontal POSITION A B SELECT TRIGGER MODE TRIGGER SOURCE TRIGGER CPLG TRIGGER SLOPE TRIGGER HOLDOFF TRIGGER LEVEL Measurements FOCUS For a viewable readout For a viewable trace CH 1 CH 2 off DC 0 5 v A 2 ms 12 o clock A Trigger AUTO LEVEL VERT AC _ positive going Min 12 o clock All off press CLEAR DISPLAY three times For best defined display b Connect time mark generator TG 501 to the CH 1 input via a 50
84. ck An Equipment Required block at the beginning of each subsection lists the equipment from Table 7 1 that is needed to do the checks in that subsection The Initial front panel control settings at the beginning of each subsection prepare the instrument for the first step of the subsection Do each of the steps in a subsection completely and in order to ensure the correct control settings for steps that follow To ensure performance accuracies stated in the Performance Characteristics Section 6 let the instrument warm up for 20 minutes and run the SELF CAL MEASUREMENTS routine To run the SELF CAL MEASUREMENTS routine Press the top and bottom menu item select buttons to display the SERVICE MENU Underline and select SELF CAL MEASUREMENTS Press RUN to start the routine then QUIT to return to the normal oscilloscope mode NOTE Performance accuracies are ensured only when the SELF CAL MEASUREMENTS is done AFTER the 20 minute warmup 7 2 2246 1Y and 2246 Mod A Operators Performance Check Procedure Table 7 1 Test Equipment Required Minimum Specification Frequency 250 kHz to above 150 MHz Output am plitude variable from 10 mV to 5 V p p Output impedance 50 0 Amplitude accuracy con stant within 1 596 of reference frequency to 100 MHz Standard amplitude signal levels Dc and Square wave 5 mV to 50 V Accuracy 0 25 High amplitude signal levels 1 V to 60 V Repetition rate 1 kHz Fast rise
85. cond Interval Disregard slow drift Delay Time Accuracy Set Horizontal MODE ALT B SEC DIV 10 us TRACE SEP Fully CCW maximum downward position CH 1 POSITION To display both the ALT and the B Delayed Traces Position the first time marker on the ALT trace to first vertical graticule line left most edge Position the intensified zone to full left position counterclockwise rotation of the Ic on DELAY control CHECK that the readout is 0 000 ms 2246 1Y and 2246 Mod A Operators 7 41 Performance Check Procedure e Position the intensified zone to the second time marker and align the leading edge of the time marker displayed on the B Trace to the left most first graticule line Using the Readout Accuracy Limits given in Table 7 4 check the delay time accuracy f Repeat the procedure for the third through t Oth time markers 9 Delay Time Position Range a Set time mark generator for 0 1 ms b Set A SEC DIV 1 ms B SEC DIV 5 ps k or DELAY control CCW to 0 000 c CHECK that the intensified zone is positioned at or before the second time mark d Turn the or DELAY control clockwise until the delay readout stops increasing largest number Table 7 4 Delay Time Accuracy Time Marker Readout Accuracy Limits 0 000 ms 2nd 0 975 ms to 1 025 ms 3rd 1 970 ms to 2 030 ms 4th 2 965 ms to 3 035 ms 5th 3 960 ms to 4 040 ms eth 4 955 ms to 5 045 ms 7th 5 950 ms to 6 050 ms
86. d on the crt face to provide parallax free viewing and enable accurate measurements see Figure 3 2 The graticule is marked with eight vertical and ten horizontal major divisions Major divisions are further divided into five sub divisions of 0 2 division each marked along the center vertical and horizontal graticule lines Percentage marks for rise time and fall time measurements are marked on the left side of the graticule Vertical deflection factors and horizontal timing are cali brated to the graticule so that accurate measurements can be made directly from the crt The waveform displays are calibrated to the crt graticule markings for making quick and very accurate measurements of waveform parameters Voltage measurements are done by counting the vertical graticule divisions and partial divisions occupied by the portion of the display being measured and then multiplying by the VOLTS DIV setting Time measurements using the graticule markings are done in a similar manner Count the number of horizontal graticule divisions and partial divisions occupied by the portion of the waveform being measured and multiply by the SEC DIV setting To improve the accuracy of the estimate position the display to take advantage of the 0 2 division minor graticule markings on the center graticule lines Also position one of the measurement points of the waveform as precisely as possible on one of the major graticule marks to be used as a measurement reference
87. d range of the two position controls exceeds the trigger level range making it possible though unlikely to pull a signal on screen for display but fail to trigger on it due to insufficient trigger level range AUTO LEVEL Does not exceed the peak to peak amplitude of the trigger signal that was present when the AUTO LEVEL limits were set TRIGGER LEVEL READOUT Accuracy 0 396 of reading 10 of one vertical division HOLDOFF Control Range Increases A Sweep holdoff time by at least a factor of 22 FUNCTIONS WITH DIGITAL READOUT Specifications for functions with digital readout are valid only when the ambient temperature is within 10 C of the temperature at the time of the last SELF CAL For maximum performance a recent SELF CAL is recommended VOLTMETER FUNCTIONS DC VOLTS 0 596 of reading 2 of one vertical division 250 nV Greater than 50 dB at 50 or 60 Hz Accuracy Normal Mode Rejection Ratio Performance Requirement not checked in manual 2246 1Y and 2246 Mod A Operators 6 9 Performance Characteristics Table 6 1 cent Electrical Characteristics CHARACTERISTICS PERFORMANCE REQUIREMENTS PLUS or MINUS PEAK Accuracy Full Bandwidth 25 Hz to 25 MHz 2 0 of reading 15 of one vertical division 1 mV Greater Than 25 MHz to 100 MHz 0 5 dB 3 dB 1 mV Follows the trigger 90 MHz at 35 C system frequency response curve to 55 C Accuracy Bandwidth Limited
88. d with NOISE REJ Trigger CPLG but does not trigger with HF REJ CPLG j Set Horizontal MODE A A B SELECT A Trigger k CHECK that the display is stably triggered with NOISE REJ Trigger CPLG but does not trigger with HF REJ CPLG The Trigger LEVEL control may be adjusted to improve display stability in NOISE REJ CPLG 4 100 MHz Trigger Sensitivity a Set TRIGGER CPLG to DC b Set leveled sine wave generator to produce a 1 0 division display at 100 MHz c CHECK that the display is stably triggered in DC LF REJ and AC Trigger CPLG the display is not triggered in HF REJ Trigger CPLG d Set Horizontal MODE B A B SELECT B Trigger e CHECK that using the Trigger LEVEL control the display can be stably triggered in DC LF REJ and AC Trigger CPLG the display can not be triggered in HF REJ Trigger CPLG f Set Horizontal MODE A VERTICAL MODE CH 2 CH 1 off CH 2 CH 3 and CH 4 VOLTS DUV 0 1 v A B SELECT A Trigger TRIGGER CPLG DC g Move test signal from CH 1 to the CH 2 input 2246 1Y and 2246 Mod A Operators 7 81 Performance Check Procedure D Set leveled sine wave generator output to produce a 1 0 division dis play amplitude at 100 MHz CHECK that a stable display can be obtained The Trigger LEVEL control may be adjusted to improve the display stability Repeat steps g through i for the CH 3 and CH 4 turn on the appro priate VERTICAL MODE and move the test signal as required 100
89. de provides two intensified zones on the A trace There are also two associated B delayed traces matching the intensified zones A direct readout of the delay difference between the two zones is displayed in the top line of crt readout Use the following procedure steps as a guideline for making delta time delay time measurements 1 Apply the signals that measurements are to be made on to the vertical input connectors Turn on the VERTICAL MODE channels needed to display the signals NOTE Probes are the most convenient for in circuit testing and coaxial cables are the most convenient when using signal generators as the source of the test signals Use correct terminations to match the output impedance of any signal generator used The CH 1 and CH 2 vertical channel provide the widest range of signs conditioning and the CH 3 and CH 4 vertical channels are most useful for digits signs levels 2 Use a VOLTS DIV setting that produces a usable vertical display ampli tude for viewing ease use an A SEC DIV setting that produces two to five repetitions or cycles of the signal across the graticule area NOTE When viewing multiple traces it is best to limit the vertical ampli tude to about two divisions so that good trace separation may be obtained in the display 3 Switch the Horizontal MODE to ALT Advance the SEC DIV setting at least one position to obtain a faster B SEC DIV setting 4 Set the B Trigger MODE to RUNS AFTER 5 Pre
90. displays provides the internal sig nal source for the trigger system when the trigger source is VERT Channel 1 and Channel 2 VOLTS DIV Switches Select cali brated deflection factors for Channel 1 and Channel 2 from 2 mV per division to 5 V per division in a 1 2 5 sequence of 11 steps 2246 1Y and 2246 Mod A Operators 2 3 Controls Connectors and Indicators VERTICAL POSITION lt gt POSITION CH2 BW INVERT COUPLING COUPLING ac Q 0c 20MH 9 o0 GND Born Der BOTH OFF 1 or IMS 20pF lt 400V pk 20pF lt 400V pk 6558 04 Figure 2 2 CH 1 and CH 2 vertical controls and indicators The switches are detented continuous rotation controls with no end stops The VOLTS DIV readouts reflect attenuation factors of coded attenuator probes connected to the vertical inputs 13 cH 1 AND CH 2 VOLTS DIV VAR Controls Allows the CH 1 and CH 2 vertical deflection factors to be increased up to at least 2 5 times 2 4 2246 Y and 2246 Mod A Operators Controls Connectors and Indicators Vertical deflection factors are greater than the VOLTS DIV switch setting when the UNCAL indicator is lit and a greater than symbol gt is displayed to the left of the associated VOLTS DIV readout UNCAL Indicator Lights when either CH 1 or CH 2 VOLTS DIV set tings are uncalibrated variable function in effect SCOPE BW Button Reduces the bandwidth of the vertical deflec tion system to 20 MHz when th
91. dling and disposal procedures for Lithium batteries 4 Performance Requirement not checked in manual 2246 1Y and 2246 Mod A Operators 6 13 Performance Characteristics Table 6 1 cent Electrical Characteristics CHARACTERISTICS PERFORMANCE REQUIREMENTS POWER SOURCE Line Voltage Range 90 Vac to 250 Vac 48 Hz to 445 Hz 2 A 250 V slow blow 100 Watts 155 Line Frequency Line Fuse Maximum Power Consumption CRT DISPLAY Display Area 8 by 10 cm Geometry Vertical 1 2 minor 0 1 div at 8 by 8 cm centered area t1 minor 0 2 div at 8 by 10 cm centered area Horizontal 1 2 minor 0 1 div at 6 by 10 cm centered area 1 minor 0 2 div at 8 by 10 cm centered area Trace Rotation Range Adequate to align trace with center horizontal graticule line Standard Phosphor 1 Orthogonality 0 1 division or less over eight vertical divisions No adjustment Nominal Accelerating 16 kV Voltage a Performance Requirement not checked in manual 6 14 2246 1Y and 2246 Mod A Operators Performance Characteristics o lt x lt 8 o a S 20 50 kHz 100 kHz 500 kHz 1 MHz 100 MHz FREQUENCY le Figure 6 1 Maximum input voltage vs frequency derating curve for the CH 1 CH 2 CH 3 and CH 4 input connectors 2246 1Y and 2246 Mod A Operators 6 15 Performance Characteristics Table 6 2 Environmental Characteristics CHARACTERISTICS DESCRIPTION
92. e displayed error message is OUCH TURN VOLTS DIV CCW NOTE When making DC measurements overranged signals will not cause an error message to be displayed but can display incorrect voltage readings To obtain accurate DC readings keep the waveform within the graticule limits The Channel 1 or Channel 2 Voltmeter measurement of DC cannot be made with the Input COUPLING set to AC the displayed error message is CH 1 or CH 2 SELECT DC COUPLING If GND Input COUPLING is in use a ground symbol is displayed after the readout value For PEAK PEAK and PK PK measurements the ac symbol will be displayed for AC Input COUPLING and the ground symbol will be displayed for GND Input COUPLING The symbols will be displayed after the readout units The following measurements cannot occur when the VOLTS DIV VAR con trol for the channel being measured is not in the detent position PEAK 3 18 2246 1Y and 2246 Mod A Operators Operators Familiarization PEAK PK PK DC GATED PEAK GATED PEAK GATED PK PK VOLTS and rh VOLTS A The displayed error message is MEAS SOURCE VAR OUT OF DETENT The following measurements cannot occur when the SEC DIV VAR control for the channel being measured is out of the detent position Ic SEC A I 1 SEC 341 PHASE and SET 360 l The displayed error mes sage is VAR SECS DIV OUT OF DETENT When in ALT or B Horizontal MODE and the B Trigger MODE is not RUNS AFT
93. e button is lit The full vertical deflection bandwidth is available when the SCOPE BW button is not lit 16 cH 2 INVERT Button Inverts the Channel 2 input signal when the INVERT button is lit The Channel 2 input signal in ADD mode and the Channel 2 trigger signal pickoff are also inverted A down arrow symbol is displayed between the Channel 1 and Channel 2 VOLTS DIV readout when the INVERT mode is on COUPLING Buttons Select the method of coupling input signals to the Channel 1 and Channel 2 attenuators GND Disconnects the Input signal and grounds the input of the associated vertical attenuator to provide a zero ground reference voltage display The COUPLING switch is in the ground position when the AC and the DC buttons are not lit A ground symbol s is displayed to the right of the associated VOLTS DIV readout The ground symbol is also displayed after the value readout of any of the VOLTMETER measurements AC Capacitively couples the input signal to the vertical attenuator when the AC button is lit Turning on AC Coupling turns off DC Coupling AC Coupling blocks the dc component of the input signal The lower 3 dB frequency limit is 10 Hz or less when using either a 1X probe or properly terminated coaxial cable it is 1 Hz or less using a compensated 10X probe With AC Coupling selected AC symbol is displayed to the right of the associated VOLTS DIV readout An ac symbol is also displayed after the value reado
94. e cursors move when the OR DELAY control is rotated Tracking Cursors Position Accuracy Press CLEAR DISPLAY press twice Set CH 1 VOLTS DIV 0 1 v MEASUREMENTS CURSORS Menu On AUTO TRACKING MENU On TRACK TRIG LVL On TRACK mh On MENU off TRIGGER MODE AUTO not AUTO LEVEL Connect calibration generator Std Ampl output via a 50 BNC cable to the CH 1 input Set calibration generator for Std Ampl output of 0 5 V Adjust TRIGGER LEVEL control to align trigger level cursor with the bottom of the signal CHECK the readout is 0 000 V 0 005 V and the GND cursor is aligned with the bottom of the signal 7 48 2246 1Y and 2246 Mod A Operators g Performance Check Procedure Set trigger level cursor to align with the top of the signal CHECK the readout is between 0 475 V and 0 525 V Press CLEAR DISPLAY Disconnect test equipment if ending here 2246 1Y and 2246 Mod A Operators 7 49 Performance Check Procedure CH1 CH 2 VOLTMETER MEASUREMENTS Equipment Required See Table 7 1 Calibration generator Leveled sine wave generator Function generator 1 DC Volts Accuracy a Set READOUT Intensity INTEN VERTICAL MODE CH 1 VOLTS DIV CH 2 INVERT SCOPE BW CH 1 Input COUPLING Horizontal MODE A SEC DIV A B SELECT TRIGGER MODE TRIGGER CPLG TRIGGER SOURCE TRIGGER SLOPE TRIGGER HOLDOFF CH1 CH2 VOLTMETER FOCUS Horizontal POSITION DC 7 50 50 BNC coaxial cable 5
95. e displayed for 5 seconds WARNING PROBABLE BATTERY FAILURE TURN OFF AND ON TO VERIFY If the message reappears after having turned the power off and on have the battery checked and or replaced by a qualified service person The instrument can still be used for accurate measurements by running the SELF CAL MEASUREMENTS routine from the SERVICE MENU after the instrument has warmed up for at least 20 minutes To run the SELF CAL MEASUREMENTS routine press the top and bottom menu item select buttons Press down arrow button to underline SELF CAL MEASUREMENTS Press RUN to start the routine then QUIT or CLEAR DISPLAY to return to the normal oscilloscope mode 1 6 2246 1Y and 2246 Mod A Operators Introduction Repackaging for Shipment Save the original shipping carton and packing material in case it is ever necessary to reship the instrument by a commercial transport carrier If the original materials are unfit or not available then repackage the instru ment using the following procedure 1 Use a corrugated cardboard shipping carton with a test strength of at least 275 pounds and an inside dimension at least six inches greater than the instrument dimensions 2 Enclose the following information owner s address name and phone number of a contact person type and serial number of the instrument reason for returning and a complete description of the service required 3 Completely wrap the instrument with polyethylene sheeting o
96. e leveled sine wave generator SG 503 output for a five division signal display amplitude at 100 MHz Set CH 2 CH 3 and CH 4 VERTICAL MODE On CH 1 off CHECK display amplitude is 0 1 division or less excluding trace width on the CH 2 CH 3 and CH 4 traces Move sine wave generator signal to the CH 2 input Set CH 1 CH 3 and CH 4 VERTICAL MODE On CH 2 off TRIGGER SOURCE CH 2 CHECK display amplitude is 0 1 division or less excluding trace width on the CH 1 CH 3 and CH 4 traces Move sine wave generator signal to the CH 3 Input Set CH 1 CH 2 and CH 4 VERTICAL MODE On CH 3 off TRIGGER SOURCE CH 3 7 24 2246 1Y and 2246 Mod A Operators Performance Check Procedure CHECK display amplitude is 0 1 division or less excluding trace width on the CH 1 CH 2 and CH 4 traces Move sine wave generator signal to the CH 4 input Set CH 1 CH 2 and CH 3 VERTICAL MODE On CH 4 off TRIGGER SOURCE CH 4 CHECK display amplitude is 0 1 division or less excluding trace width on the CH 1 CH 2 and CH 3 traces Disconnect the test setup 22 AC Coupled Lower 3 dB Point a Set A SEC DIV 50 ms VERTICAL MODE CH 1 ail others off TRIGGER SOURCE VERT TRIGGER MODE NORM Connect function generator FG 502 output to the CH 1 input via a 50 BNC coaxial cable and a 50 BNC termination Set the function generator output controls to produce a six division sine wave display at 10 Hz with no
97. e levels MENU first MEASUREMENT and TRACK MEASMT cursors second and TRACK TRIG LVL and TRACK lt cursor last The highest level being displayed is turned off each time the CLEAR DISPLAY button is pressed TRACK MEASMT Press to enable or disable the Channel 1 or Chan nel 2 Voltmeter measurement tracking cursors that show the waveform measurement points The state of the TRACK MEASMT feature does not affect the positionable rh VOLTS gt cur sor operation The CLEAR MENU button will not turn off the TRACK MEASMT feature it only turns off the present display of the TRACK MEASMT cursor when it turns off the active measurement mode The next time a Channel 1 or Channel 2 VOLTMETER measurement mode is selected the TRACK MEASMT cursor or cursors will again be displayed TRACK TRIG LVL Press to enable or disable the Trigger Level tracking cursor See Conditions For Cursors Display in this section for conditions required to display the Trigger Level tracking cursors TRACK 7 Press to enable or disable the ground level tracking cur sor The TRACK cursor follows the VERTICAL MODE in that it fol lows the lowest displayed channel of either CH 1 or CH 2 BACK TO PREVIOUS MENU Returns the first page of the Cursors menu MENU OFF Clears the menu from the display Time Menus Press the TIME button to call up the time measurement choices shown in Figure 3 7 Vertical cursors are displayed for use in setting the time
98. e signal is on screen VOLTS DIV and POSITION Horizontal SEC DIV so that at least 1 cycle is displayed Horizontal MODE A or X Y 3 Press the CURSOR VOLTS button to display the measurement selection menu and select the I VOLTS gt cursors The voltage cursors are initialized to the peak to peak levels of the lowest numbered displayed channel of either CH 1 or CH 2 see Figure 5 3 PK PK VOLTAGE Figure 5 3 Voltage difference measurement using cursors 2246 1Y and 2246 Mod A Operators 5 7 Basic Applications NOTE Voltage cursors are initialized to leve s seen by the peak detector circuitry Noise and other signals riding on the signal to be measured will cause a slight displacement of the cursors from the displayed waveform peaks and above 50 MHz the bandwidth rolloff of the trigger circuit will affect the initial cursor positions on the waveform 4 For a peak to peak voltage measurement slightly reposition the cur sors as necessary to precisely align them with the peak amplitudes of the waveform and the work is done The k OR DELAY control positions both cursors together keeping the original spacing and the control positions the independent cursor Then simply read the measurement value displayed in the top line of the readout 5 To make voltage difference measurements between any other locations on the waveform simply move the e cursor to the new point of interest and then position the independent cursor to
99. ection rate sweep speed for both the A sweep and the B sweep in a 1 2 5 sequence Calibrated sweep speeds are obtained with the A and B SEC DIV VAR control in the detent fully clockwise position The A SEC DIV switch setting is set only from the A Horizontal MODE and the B SEC DIV switch is set only from the ALT or B Horizontal MODE 2246 1Y and 2246 Mod A Operators 2 9 Controls Connectors and Indicators NOTE The B sweep speed can never be slower than the A sweep speed When the two sweep speeds are the same they are locked At this point A will follow B to slower SEC D V settings in ALT or B and B will follow A to faster settings in A A SEC DIV The calibrated A sweep speed is selected only in A Hori zontal MODE from 0 5 s per division to 20 ns per division X10 MAG off B SEC DIV The calibrated B sweep speed is selected either in ALT or B Horizontal MODE from 5 ms per division to 20 ns per division X10 MAG off 28 A and B SEC DIV VAR Control Provides continuously variable uncalibrated A and B sweep speeds to at least 2 5 times slower than the calibrated SEC DIV setting The VAR control extends the slowest A sweep speed to at least 1 25 sec per division The UNCAL indicator is lit and a greater than sign is displayed before each SEC DIV readout value when the sweep speeds are greater than the SEC DIV settings CURSORS TIME POSITION Controls Sets the reference and delta cursors on the display N
100. ent mode If the SET MEAS MT CHANNEL button is pressed for an invalid mode one of the following messages will be displayed in the top line for about two seconds SELECT A MEASUREMENT When no measurement mode is active NO MEAS CHANNEL NEEDED When a selected measurement mode such as cursor time does not require that a measurement channel be set SET MEASMT CHANNEL Figure 3 3 Voltmeter measurement channel menu 3 6 2246 1Y and 2246 Mod A Operators Operators Familiarization SET DELAY TIME CHANNEL CH4 CH2 CH3 CH4 ADD TO A CHANNEL MENU SET TIME CHANNEL Figure 3 4 Delay Time Delta Time channel menu 2246 1Y and 2246 Mod A Operators Operators Familiarization When a SET MEAS MT CHANNEL menu is displayed changing the Hori zontal MODE except between ALT and B clears the menu and turns off the active measurement mode Pressing a menu button next to a vertical channel number selects that choice as the source channel for the measurement For Channel 1 or Chan nel 2 Voltmeter measurements the selected source channel need not be displayed and Is not automatically turned on when selected It is possible therefore to view a Channel 1 display and have the Channel 2 voltage measurement value displayed by the readout and vice versa When setting the measurement channel for VOLTS 9 or fh VOLTS gt or when setting delay time and delta time channels a vertical channel that is selected in the m
101. enu is turned on if not previously selected and it remains displayed when deselected as the measurement source channel Any vertical channel traces turned on that are not wanted in the display must be turned off using the VERTICAL MODE buttons Recalling the Last Measurement Mode Press LAST MEAS MT to recall the last selected measurement mode if no measurement mode is active The LAST MEAS MT button may also be used to reinitialize an active measurement mode A press of the button cancels the active measurement and then recalls it in its initialized state This feature is quite useful for returning VOLTS cursors to their initialized positions after they have been adjusted away Channel 1 and Channel 2 Voltmeter Press VOLTMETER CH1 CH2 button to display the choices of page 1 shown in Figure 3 5 NOTE If a single channel CH 1 or CH 2 is selected for display it be comes the default measurement source channel If both CH 1 and CH 2 are being displayed the default measurement source channel upon each initialization is CH 1 Use the SET MEAS MT CHANNEL function to assign CH 2 as the measurement channel Turn off the CH 1 display if CH 2 is the desired default measure ment source channel If both CH 1 and CH 2 are turned off when a Voltmeter measurement is active the error message VOLT METER SOURCE CH 1 OR 2 ONLY will be displayed and the voltmeter measurement will be canceled 3 8 2246 1Y and 2246 Mod A Operators Operators Famili
102. erimposed waveforms horizontally to the center vertical graticule line Set X10 MAG On for 2 ns div sweep speed CHECK that the leading edges of the two waveforms have less than 0 2 horizontal division separation at the center graticule line excluding trace width CH 1 to CH 4 Signal Delay Match Set VERTICAL MODE to CH 1 and CH 4 CH 2 off Move the CH 2 signal to the CH 4 input connector 2246 1Y and 2246 Mod A Operators 7 19 Performance Check Procedure 15 16 Superimpose the CH 4 waveform on the CH 1 waveform CHECK that the leading edges of the two waveforms have less than 0 4 horizontal division separation at the center graticule line excluding trace width CH 3 to CH 4 Signal Delay Match Set VERTICAL MODE CH 3 and CH 4 CH 1 off TRIGGER SOURCE CH 2 Move the CH 3 trigger signal to the CH 2 input and the CH 1 signal to the CH 3 input Superimpose CH 3 and CH 4 waveforms at the center graticule line using the HORIZONTAL POSITION control if necessary CHECK that the leading edges of the two waveforms have less than 0 2 horizontal division separation at the center graticule line Disconnect the test setup CH 1 and CH 2 Vertical Bandwidth Set X10 MAG off VERTICAL MODE CH 1 CH 3 and CH 4 off SEC DIV 0 1 ms CH 1 VOLTS DIV 5 mV CH 1 and CH 2 Input COUPLING DC TRIGGER SOURCE VERT Horizontal POSITION 12 o clock Connect the leveled sine wave generator SG 503 output to the CH 1 I
103. fied on the back of your product and in Table 6 1 Do Not Operate in an Explosive Atmosphere To avoid explosion do not operate this product in an explosive atmosphere x 2246 1Y and 2246 Mod A Operators Do Not Remove Covers or Panels Excluding Front Panel Cover To avoid personal injury do not remove the product covers or panels Do not operate the product without the covers and panels properly installed 2246 1Y and 2246 Mod A Operators REV JUN 1989 xi SECTION 1 INTRODUCTION 2246 1Y and 2246 Mod A Introduction PRODUCT OVERVIEW Description The 2246 1Y and 2246 Mod A are 100 MHz four channel dual sweep portable oscilloscopes for general purpose use Figure 1 1 A microprocessor based operating system controls most of the functions in the instruments including a fully Integrated menu driven voltage and time measurement system with SmartCursors A menu driven service mode provides for configuring of certain menu and readout displays internal calibration and servicing diagnostics 7061 01 Figure 1 1 The 2246 1Y and 2246 Mod A Oscilloscope 2246 1Y and 2246 Mod A Operators 1 1 Introduction The vertical deflection system has four input channels Two channels have 11 basic deflection factors from 2 mV to 5 V per division and two channels have two basic deflection factors of 0 1 V and 0 5 V per division Basic deflection factors can be extended with attenuator probes VOLTS DIV readouts are switched to
104. gt menu choice Use the OR DELAY control to align the first cursor to the rising edge at the point it crosses the 10 reference graticule line Then use the 3 control to align the second cursor to the point the rising edge crosses the 9096 graticule line and read the rise time displayed in the top line of the crt readout see Figure 5 7 Phase Measurements Making a phase measurement is done by first setting a reference for the full 360 degree waveform period Use the following procedure as a guide 1 3 Apply the reference waveform to the CH 1 input connector any channel may be used but CH 1 and CH 2 provide the most signal scaling possibilities Use the standard 10X attenuator probe supplied with the instrument to make the signal connections as they produce very little signal loading to a circuit under test and produce matched delays For phase measurements external loading of a circuit and different delays in the signal connection paths will produce incorrect results Select CH 1 for display using the VERTICAL MODE buttons and set the Input COUPLING for CH 1 and CH 2 to DC AC may be used if the signals to be measured are riding on a dc voltage but set both Inputs to the same coupling AC coupling produces some signal phase shift especially at lower frequencies Set the CH 1 VOLTS DIV control to display the reference waveform with about five divisions of amplitude Vertically center the waveform Set the A SEC DIV
105. h set to the same setting the total deflection factor In the ADD mode is equal to the deflection factor indicated by either VOLT DIV readout The l VOLTS gt I 5 24 2246 1Y and 2246 Mod A Operators Basic Applications cursors may be used to make voltage measurements on the ADD trace if either CH 1 or CH 2 is displayed along with the ADD trace and of course both CH 1 and CH 2 at the same VOLTS DIV setting If any voltage measurement function is active turning off CH 1 and CH 2 to display the ADD trace by itself causes the message VOLTMETER SOURCE CH 1 or 2 ONLY to appear and cancels the measurement If calling for a voltage measurement with ADD displayed and neither CH 1 nor CH 2 displayed the CH 1 VERTICAL MODE is turned on and the measurement is initialized to the signal applied to the CH 1 input Two common uses for ADD mode are 1 providing a dc offset to bring an ac signal riding on top of a large dc voltage within the graticule viewing area and 2 canceling out a large line frequency signal component to view some small feature riding on the waveform in greater detail using common mode rejection The following general precautions should be observed when using ADD mode a Do not exceed the input voltage rating of the oscilloscope or probe b Do not apply signals that exceed the equivalent of about eight times the VOLTS DIV switch settings since large voltages may distort the display For example with a VOLTS DIV set
106. he I OR DELAY control and the width is set using the control Gated measurements are not allowed In SGL SEQ Trigger MODE active gated measurements will be canceled if SGL SEQ Trigger MODE is selected If the menu is displayed in SGL SEQ TRIGGER MODE a gated measurement selection will call up a NOT ALLOWED IN SSEQ message to be displayed for about two seconds GATED PEAK Measures the most positive screen relative voltage in the gated intensified portion of the waveform GATED PEAK Measures the most negative screen relative voltage in the gated intensified portion of the waveform 3 70 REV AUG 1988 2246 1Y and 2246 Mod A Operators Operators Familiarization GATED PK PK Measures the peak to peak voltage in the gated intensified portion of the waveform BACK TO PREVIOUS MENU Returns the first page of the Voltmeter menu Cursors Measurements Press CURSORS to display the measurement choices of menu 1 shown in Figure 3 6 NOTE Changing the Horizontal MODE will remove the Volts Cursors from the display Set Horizontal MODE back to A or X Y and press LAST MEAS MT button to redisplay cursors le VOLTS gt Measures the equivalent voltage difference between two horizontal cursors in either A Horizontal MODE or X Y Horizontal MODE Both cursors are positioned by OR DELAY control and the delta cursor is positioned by the control When the VOLTS cur Sors measurement is first turned on or recalled a
107. he menu by selecting the TO AUTO TRACKING MENU choice Of the three features avail able in page 2 select both TRACK MEASMT and TRACK fh Menu labels are UNDERLINED when the function is enabled The TRACK s cursor is especially useful for providing feedback to the user about dc offset of the signal from ground level NOTE In this menu the select buttons toggle the choices on and off with each press and all three choices may be selected but not all displayed together because only two cursors are allowed Also pressing CLEAR DISPLAY as many as three times may be necessary does turn off the TRACK TRIG LVL and TRACK th choices Press either MENU OFF in the menu selection list or CLEAR DISPLAY once to remove the AUTO TRACKING menu from the display NOTE If VOLTMETER PK PK measurement is selected two TRACK MEASMT cursors are required therefore the TRACK cursor will not be displayed See Figure 5 1 The test signal used for the example has a dc offset as shown by the position of the TRACK th cursor and PEAK value peak ac dc as indicated by the voltage readout 2246 1Y and 2246 Mod A Operators 5 3 Basic Applications Gated Voltage Measurement If you need to track the PEAK PEAK or PK PK voltage of a selected portion of a waveform that portion can be defined using the GATED MEASUREMENTS available in page 2 of the VOLTMETER menu The general steps given in the previous Peak Voltage Measurement procedure
108. htness of the A trace B INTEN Control Adjusts the brightness of the B Delayed sweep trace and the intensified zone on the A trace FOCUS Control Adjusts the focus of the crt displays traces readout and cursors TRACE ROTATION Control Aligns the crt trace with the horizontal graticule lines This is a screwdriver adjustment READOUT Control Adjusts the brightness of the crt readout display includes all alphanumerics and cursors SCALE ILLUM Control Adjusts the illumination level of the graticule NOTE Life of the graticule illumination lamps can be increased by setting the SCALE ILLUM control for the minimum intensity needed for viewing and turning off scale illumination when not needed 8 BEAM FIND Button Locates off screen and overscanned displays when the button is held in Limits the vertical and horizontal deflection within the display area and unblanks the CRT 2246 1Y and 2246 Mod A Operators 2 1 Controls Connectors and Indicators Tektronix 12246 100 Hz OSCILLOSCOPE BEAM FIND SCALE PROBE Ate A INTEN B INTEN ILLUM ER 9 Figure 2 1 CRT power and display controls CRT Displays waveforms and readouts in an 80 mm vertical by 100 mm horizontal graticule area Internal graticule lines provide parallax free viewing of trace and graticule lines 0 1096 90 and 100 points marked at the left edge of the graticule aid in making rise and fall time measurements 2
109. ibrated detent Channel 1 COUPLING GND 2246 1 and 2246 Mod A Operators 4 1 Operator Checks and Adjustments Horizontal Controls MODE POSITION X10 MAG A SEC DIV SEC DIV VAR Trigger Controls HOLDOFF A B SELECT MODE SOURCE CPLG Display INTEN FOCUS READOUT SCALE ILLUM MENU System Controls MEASUREMENT MODES TRACKING CURSORS and MENUS A Center the trace Off 0 1 ms Calibrated detent MIN A AUTO LEVEL VERT DC Desired brightness Best trace definition Desired brightness Desired brightness All off Press CLEAR DISPLAY three times to ensure all off Trace Rotation Adjustment Perform the Initial Setup procedure Position the trace vertically to align it with the center horizontal graticule line and check that the trace is parallel with the gratlcule line Normally NOTE the trace will be parallel to the center horizontal graticule line and the TRACE ROTATION adjustment will not be needed 4 2 2246 1Y and 2246 Mod A Operators 2 Operator Checks and Adjustments If necessary adjust the TRACE ROTATION to make the baseline trace parallel to the center horizontal graticule line Use a small straight blade screwdriver or alignment tool Probe Low Frequency Compensation Misadjustment of probe compensation is a possible source of measurement error The attenuator probes are equipped with compensation adjustments To ensure the best measurement accuracy always check
110. icule rise time measurement aids Notice that on the left edge of the graticule the numbers 10 90 and 100 are etched These marks provide convenient reference points when the signal to be measured is properly set up Use the following procedure steps as a guide line In making rise time measurements 1 Apply the signal to CH 1 Input connector 2 Set Vertical MODE CH 1 Horizontal MODE A 3 Set the VOLTS DIV and VOLTS DIV VAR controls to provide an exact five division vertical display 5 12 2246 1Y and 2246 Mod A Operators Basic Applications 4 Use the Vertical POSITION control to place the negative amplitude of the signal on the 0 reference line and the positive amplitude on the 100 reference line 5 Advance the SEC DIV setting to stretch out the rising edge of the waveform as much as possible to improve the cursor placement accuracy see Figure 5 7 NOTE If measuring fall time use negative SLOPE This places the trig ger point at the beginning of the sweep so that when the SEC DIV setting is advanced the slope of interest remains within the viewing area RISETIME Figure 5 7 Rise time measurements 2246 1Y and 2246 Mod A Operators Basic Applications 7 Increase the A INTEN control If necessary to brighten the beginning of the trace and use the Horizontal POSITION control to place the rising edge of the waveform at the center vertical graticule line Press TIME button and select the k SEC
111. ide Handles 44 mm 1 75 in Required Clearance dimensions Helght 2 178 mm 7 in Width 2 448 mm 17 5 8 in Depth 2 508 mm 20 in Cooling Forced air circulation no air filter Finish Tek Blue pebble grain finish painted on aluminum cabinet Construction Aluminum alloy chassis front panel frame and rear support Plastic laminate front panel Glass laminate circuit boards 2246 1Y and 2246 Mod A Operators 6 21 Performance Characteristics 6 44 164 6 16 5e 11 82 300 16 99 432 Dimensions are in inches mm Figure 6 2 Dimensional drawing standard cabinet 6 22 2246 1Y and 2246 Mod A Operators Performance Characteristics 2 0 in 51 mm CLEARANCE RECOMMENDED AT REAR AND SIDES FOR COOLING AND INSTRUMENT CONNECTIONS SIDE VIEW 183m en mm 19 0 in 483 mm FRONT VIEW 6556 37 Figure 6 3 Dimensional drawing rackmount cabinet 2240 F1R 2246 1Y and 2246 Mod A Operators 6 23 SECTION 7 PERFORMANCE CHECK PROCEDURE 2246 1Y and 2246 Mod A Performance Check Procedure Introduction This Performance Check Procedure verifies the Performance Requirements of the 2246 1Y or 2246 Mod A as listed in the Performance Characteristics Section 6 and helps determine the need for readjustment These checks may also be used as an acceptance test or as a preliminary troubleshooting aid You do n
112. ied Timing Accuracy and Linearity 7 40 Delay Time 7 41 Delay Time 7 41 Delay Time Position Range 7 42 Gain 7 43 X Y Phase Difference llle 7 43 X Axis Bandwidth 7 44 iv 2246 1Y and 2246 Mod A Operators TIME AND CURSORS MEASUREMENTS ic SEC A and e 1 SEC Cursor Accuracy Delta Time Ic PHASE 4 Cursor Ic VOLTS Cursor VOLTS 3 Cursor Accuracy racking Cursors Position CH 1 CH 2 VOLTMETER MEASUREMENTS DC Volts DC Volts Normal Mode Rejection Ratio Peak Peak Peak to Peak Voltage Accuracy 25 MHz Peak Peak and Peak to Peak Volts Accuracy 100 MHz Peak Peak and Peak to Peak Volts Accuracy Gated Volts EXTERNAL Z AXIS PROBE ADJUST AND FACTORY SETTINGS Functions 2 5 2222220 Check External Z Axis Input m onen PROBE ADJUST Run MAKE FACTORY SETTINGS Routine SECTION 8 OPTIONS AND ACCESSORIES Introd ctioh 2 322 PUER Usu e Etats Option 2R
113. in the crt readout Measurement tracking and or ground tracking cursors may be displayed to give the user instant feedback about where on the applied signal the measurement is being made and the location of ground level GATED modes of PEAK PEAK and PK PK measurements may be used to define the area of the measurement on the displayed waveform The position and width of the gated region is displayed as an intensified zone on the A trace of the waveform display Position of the gated region on the waveform is controlled by the OR DELAY control and width of the gated region is controlled by the control Some features of the CH 1 CH 2 Voltmeter function are a Measures CH 1 or CH 2 while viewing either channel Select the measurement source channel using the SET MEAS MT CHANNEL menu b Measures signal levels DC values and peaks in SGL SEQ single sequence Trigger MODE continuously Use CONFIGURE function in the Service Menu to get menus and readouts to remain on between single sequence triggers 2246 1Y and 2246 Mod A Operators 5 1 Basic Applications To c Finds peaks of signal applied not only just the displayed portions of the waveform d Defines a portion of the waveform GATED measurements are es pecially useful for making measurements on a multi level signal on which to make the selected measurement Use page 2 of the VOLTMETER menu to select a GATE D measurement mode NOTE Very narrow gated measu
114. int A Figure 5 9 and the B sweep display of that point is at the center vertical graticule line 8 Set the control so that the delta delay intensified zone Is positioned at the second point of interest point B Figure 5 9 and the B sweep display of that point is at the center graticule line The time difference between the two points of Interest Is displayed at the top of the screen Once the measurement points are identified the A Intensified Sweep traces may be removed from the display for ease in viewing the B Sweep traces by switching to B Delayed Horizontal MODE In B Horizontal MODE exact placement of the two delays may be obtained by positioning one trace over the other and then aligning the measurement point using the j control Additional resolution may be obtained by advancing the SEC DIV Switch setting to further expand the B Sweep traces 5 18 2246 1Y and 2246 Mod A Operators Basic Applications A FIRST POINT OF INTEREST TIME DIFFERENCE J REFERENCE SECOND POINT GRATICULE LINE OF INTEREST Figure 5 9 Time difference between the two delays Track Trigger Level Cursors For most general purpose applications the AUTO LEVEL Trigger MODE provides the user with the easiest method to obtain stable waveform trig gering When information regarding the actual trigger level setting is needed to set special triggering levels for NORM or SGL SEQ triggering the user may use the TRACKING CURSORS features of the
115. ions of the 2246 1Y and 2246 Mod A are in Table 6 2 and Mechanical Specifications are in Table 6 3 Recommended Calibration Schedule To ensure accurate measurements check the performance of this Instrument every 2000 hours of operation once each year if used infrequently When components are replaced affected circuits may have to be readjusted NOTE The silver oxide batteries used in the 2246 1Y MUST BE REPLACED AT LEAST EVERY 12 MONTHS to ensure proper operation of the instrument 2246 1Y and 2246 Mod A Operators 6 1 Performance Characteristics Table 6 1 Electrical Characteristics CHARACTERISTICS PERFORMANCE REQUIREMENTS VERTICAL DEFLECTION SYSTEM CH 1 AND CH 2 Deflection Factor Range 2 mV div to 5 V div In 1 2 5 sequence Accuracy Includes ADD MODE and CH 2 INVERT 15 C to 35 C Within 2965 10 C to 15 C 35 C to 55 C Within 3 2 Variable Range Increases deflection factor by at least 2 5 1 Frequency Response 3 dB bandwidth 2 mV to 5 V div Dc to 100 MHz at the Input BNC and with a 10X probe AC Coupled Lower 3 dB Point 1X Probe 10 Hz or less 10X Probe 1 Hz or less Step Response 5 division step Rise Time 2 mV to 5 V div 3 5 ns or less calculated 4 a Performance Requirement not checked in manual 6 2 2246 1Y and 2246 Mod A Operators Performance Characteristics Table 6 1 cent Electrical Characteristics CHARACTERISTICS Aberrations Positive G
116. kwise to move the gate zone closer to the beginning of sweep 3 Use the k OR DELAY control to position the intensified zone to the area of interest on the waveform to be tracked See Figure 5 2 4 The width of the gated zone Is controlled by the 34 control Adjust the width to define the gated measurement zone 5 The voltage value that appears In the readout Is the PEAK voltage that occurs within the zone 2246 1Y and 2246 Mod A Operators 5 5 Basic Applications GATED PEAK VOLTAGE ZONE IN GATED ZONE Figure 5 2 Gated voltage measurement Voltage Measurement Cursors Voltage cursors can be used to measure signals displayed on CH 1 or CH 2 Voltage measurements using cursors may be done on the CH 3 the CH 4 or the ADD waveform by setting the VOLTS DIV switch setting of the selected measurement channel to the same scale factor as the signal to be measured However the measurement accuracy on the CH 3 or CH 4 input signals will be less accurate than on the CH 1 or CH 2 input signals Volts cursors are also available for making measurements in both the A Hori zontal MODE and the X Y Horizontal MODE Voltage Difference Use the following procedure steps as a guideline in making voltage dif ference measurements using the positionable cursors 1 Apply the signal to the input connector s 5 6 2246 1Y and 2246 Mod A Operators Basic Applications 2 Set Vertical MODE As desired CH 1 and or CH 2 so that entir
117. measurement points in A Horizontal MODE In ALT Horizontal MODE the delay measure ment is made using either the Intensified zones as the measurement points or the alternate B delayed sweeps For B Delayed Horizontal MODE the delayed sweeps only are available for making timing measurements 2246 1Y and 2246 Mod A Operators 3 13 Operators Familiarization TIME ke SEC he 1 SEC He PHASE SELF CAL Figure 3 7 Time measurement menu When the Horizontal MODE is either ALT or B the B Trigger MODE must be set to RUNS AFTER if not the following message will be displayed USE RUNS AFTER DELAY TRIG MODE If the B Trigger MODE is switched away from RUNS AFTER using the front panel Trigger MODE buttons a selected TIME measurement will be canceled Pressing LAST MEAS MT will restart the last selected TIME measurement only if the B Trigger MODE is set to RUNS AFTER and no other measurement type has been selected first In the A Horizontal MODE cursors are used to make the time measure ments in ALT or B Horizontal MODE the timing measurements are made using either the intensified zones that appear in the A sweep trace in ALT Horizontal MODE or the B delayed waveforms in either ALT or B Horizontal MODE The OR DELAY control positions both cursors or delay times reference and delta together and the control positions the inde pendent delta cursor or delay when TIME measurements are selected A selected TIME measurement m
118. n ALT if conditions are met The labels for the Trigger Level cursors are A TL A trigger level B TL B trigger level The A and B Trigger LEVEL readouts include the sign the integer and decimal fractional value of the level and the units when a cursor is displayed For example A TL 43 25 mV NOTE In the AUTO LEVEL trigger mode when no waveform is displayed the trigger eve cursor will be positioned at the level at which triggering would occur The A and B Trigger Level Cursors are not guaranteed to reach the waveform if the Horizontal POSITION control is set fully clockwise Also since the Trigger LEVEL cursor may be located anywhere within the viewing area and beyond the labels for those cursors may overlap each other or the PK PK and DC or TRACK cursor labels in the displays The Trigger Cursor Channel is determined from the Trigger Source as indi cated in Table 5 1 2246 1Y and 2246 Mod A Operators 5 21 Basic Applications Table 5 1 Trigger Cursor Channel A or B Trigger Source A or B Cursor Channel VERT Lowest numbered channel displayed CH 1 or CH 2 CH 1 CH 1 CH 2 CH 2 CH 3 Not used CH 4 Not used LINE Not used To enable the TRACK TRIG LVL cursors press the CURSORS button to call up page one of the menu The last selection In the menu Is TO AUTO TRACKING MENU Press the menu select button for that choice to display page 2 with the tracking cursor choices All of the choices TRACK MEAS
119. nd or CH 2 VOLTS DIV VAR control is in detent Behavior for Horizontal Mode Changes If the Horizontal MODE is changed to a mode that cannot be used for the active measurement that measurement will be canceled without a mes sage being displayed Returning to a mode that may be used and pressing the LAST MEAS MT button will restore the canceled measurement mode if no other measurement selection is made first See Table 3 1 for com patible and incompatible modes The only Trigger MODE restriction is that gated voltage measurements will not run in SGL SEQ Trigger MODE Any gated measurement that is active will be canceled if SGL SEQ Trigger MODE is selected If a gated voltage measurement is selected while SGL SEQ is also selected the message NOT ALLOWED IN SSEQ is displayed for two seconds only if the menu is configured to remain on after the selection is made 2246 1Y and 2246 Mod A Operators 3 17 Operators Familiarization Table 3 1 Behavior for Horizontal MODE Changes Measurement Compatible Incompatible Mode Horizontal Horizontal Modes Modes fh VOLTS gt l l VOLTS A A ALT B Measurement Compatibility and Error Messages l SEC gt i ie 1 SEC 9 ec PHASE 9 DC PEAK PEAK PK PK A GATED PEAK GATED PEAK GATED PK PK Channel 1 or Channel 2 Voltmeter measurements except DC cannot be made when the signal is larger than the range of the B trigger level Th
120. ned in front of the reference cursor 5 Use the OR DELAY control to position the reference cursor to the point on the waveform to be measured from Use the control to position the independent cursor to the second point of interest Then read the time difference value in the top line of the crt readout 5 10 2246 1Y and 2246 Mod A Operators Basic Applications Period Measurement This measurement Is basically a time difference measurement The le SEC gt cursors are positioned to define a full period of the input waveform and the value is displayed Use the setup for making time difference measurement as a guideline for making period measurements see Figure 5 5 PERIOD Figure 5 5 Period measurement Frequency Measurement A frequency measurement is made the same as the period measurement the difference being that the e 1 SEC cursors are selected from the TIME menu The measurement value Is displayed with units of frequency When the exact period is defined by positioning the cursors the frequency of the signal Is displayed Use the same front panel setup as for making a time difference measurement as a guideline for making frequency measurements with cursors see Figure 5 6 2246 1Y and 2246 Mod A Operators 5 11 Basic Applications FREQUENCY Figure 5 6 Frequency measurement Rise Time Measurements Making rise time or fall time measurement requires some additional signal scaling to use the grat
121. nput via a 50 precision BNC coaxial cable and a 50 BNC termination Set the Leveled Sine Wave Generator output for a six division signal amplitude at 50 kHz Set the generator Frequency Range and Frequency Variable controls for a 100 MHz output signal 7 20 2246 1Y and 2246 Mod A Operators 17 Performance Check Procedure CHECK the displayed signal amplitude is 4 2 divisions or more Repeat the frequency setup and CHECK procedure for VOLTS DIV settings of 50 mV and 0 5 V Move the test signal to the CH 2 input Set VERTICAL MODE CH 2 CH 1 off CH 2 VOLTS DIV 5 mV Repeat the complete Bandwidth check procedure for Channel 2 CH 3 and CH 4 Vertical Bandwidth Set VERTICAL MODE CH 3 CH 2 off CH 3 and CH 4 VOLTS DIV 0 1 v Connect leveled sine wave generator SG 503 output to the CH 3 input via a 50 precision BNC coaxial cable and a 50 BNC termination Set the generator output for a six division signal display at 50 kHz Set the generator Frequency Range and Frequency Variable controls for a 100 MHz output frequency CHECK that the signal display amplitude is 4 2 divisions or more Repeat the procedure for 0 5 VOLTS DIV setting Move the test signal to the CH 4 Input Set VERTICAL MODE to CH 4 CH 3 off Repeat the procedure for CH 4 Disconnect test setup 2246 1Y and 2246 Mod A Operators 7 21 Performance Check Procedure 18 CH 1 and CH 2 Aberrations a 19 a set VERT
122. o 20 ns b Set time mark generator for 20 ns time marks C Position the time marker peaks vertically to the center horizontal graticule line allows use of the minor division graticule markings as an aid in making the accuracy checks d Position the second time marker to the second vertical graticule line e CHECK that the tenth marker is within 0 16 division of the tenth graticule line f CHECK that In any group of three time markers having the first and third markers aligned with their respective graticule lines the second marker is within 0 05 division of its graticule line g Repeat the procedure for all other SEC DIV settings Use Table 7 3 Settings for Timing Accuracy Checks for the SEC DIV and time mark generator settings h Set SEC DIV to 20 ns i Set time mark generator for 20 ns time marks j Set Horizontal MODE B B INTEN For a viewable display k Repeat the CHECK procedure for all B SEC DIV settings 7 38 2246 1Y and 2246 Mod A Operators Performance Check Procedure Table 7 3 Settings for Timing Accuracy Checks SEC DIV Setting Time Mark Setting Normal X10 MAG Norma X10 MAG 2246 1Y and 2246 Mod A Operators 7 39 Performance Check Procedure 6 A and B Magnified Timing Accuracy a b Set time mark generator for 5 ns time marks Set Horizontal POSITION 12 o clock Horizontal MODE A A SEC DIV 20 ns Horizontal MODE B X10 MAG On for 2 ns div sweep speed C
123. ode is underscored when the menu is dis played Only one active measurement at a time is allowed Making a 3 14 2246 1Y and 2246 Mod A Operators Operators Familiarization Selection removes the menu unless SERVICE mode CONFIGURE menu is set to keep menu on when measurement selected The selected measure ment type and value are displayed at the top of the screen k SEC Press to measure the equivalent time difference between the two vertical cursors displayed in the A Horizontal MODE or the two time delays in ALT or B Horizontal mode The position of both cursors or both delays is controlled by the Jc OR DELAY control the position of the delta cursor or the delta delay is controlled by the control The measured time difference between the two cursors or delays is displayed in the crt readout If the Horizontal MODE is X Y pressing the SEC button causes the message USE A ALT OR B MODEF to be displayed for two seconds Changing the Horizontal MODE to X Y after l SEC has been activated will cancel the measurement with no message le 1 SEC Measures the time difference in frequency units hertz between the cursor positions in A Horizontal MODE or between the delay time setting and the delta delay time setting in either ALT or B Horizontal MODE Measurement points are the left ends of the two intensified zones in ALT Horizontal MODE le PHASE 4 Calls up a lower level menu for phase measurement operation lec
124. of menu items at the right side of the menu display VOLTMETER CH1 CH2 Calls up the voltage measurement menu A selected measurement mode is shown by an underlined menu item Tracking cursors measurement ground trigger level may be dis played to provide visual feedback to the user about the measurement points on the displayed signal see CURSORS CURSORS Calls up the menu for selecting cursor volts measurement modes The first page of the menu lets you select positionable cur sors page 2 is for selecting the auto tracking SmartCursors TIME Calls up the menu to select the type of timing measurement to be made Menu choices are listed on the right side of the screen 2246 1Y and 2246 Mod A Operators 2 21 SECTION 3 OPERATORS FAMILIARIZATION 2246 1Y and 2246 Mod A Operators Familiarization BASIC OPERATION This subsection contains the basic operating information and techniques that should be considered before attempting any measurements For lo cation and function of Instrument controls connectors and indicators see CONTROLS CONNECTORS AND INDICATORS Section 2 of this manual Readout Display The crt readout display indicates how the instrument controls are set up No physical markings are on the rotating switches and control knobs to indi cate the control setting A key to the location and type of readout infor mation displayed is illustrated in Figure 3 1 Graticule The graticule is internally marke
125. og or contact your local Tektronix Field Office or representative Option 2R Rackmounted Instrument The 2246 2R Is a rackmounted 2246 1Y Oscilloscope It is shipped in a configuration that permits easy installation Into a 19 inch wide equipment rack Also an optional rackmounting kit may be ordered to convert the standard 2246 1 Y or 2246 MOD A to a rackmounted instrument See Section 6 Performance Characteristics for specifications and a dimensional drawing of the rackmounted instrument Refer to the Service manual for instructions on Installing a rack adapted instrument into an equipment rack or for converting the standard instru ment to a rackmounted instrument Except for the removal of the Front Cover the Standard Accessories for the 2246 2R are the same as those listed for the 2246 1Y instrument Options A1 A5 International Power Cords Instruments are shipped with the detachable power cord option as ordered by the customer Descriptive Information about the international power cord options Is provided in Preparation for Use subsection in Section 1 Order power cords only by option number and description The optional power cords available for the 2246 1 Y and 2246 Mod A are as follows Standard North American 120 V 60 Hz 74 in Option Al Universal Euro 220 V 50 Hz 2 5 m Option A2 UK 240 V 50 Hz 2 5 m Option A3 Australian 240 V 50 Hz 2 5 m Option A4 North American 220 V 50 Hz 2 5 m Option A5 Switzerland 22
126. oing Step 5 mV div to 0 5 V div 1 V div to 5 V div Negative Going Step Position Effect Temperature Effect Delay Match CH 1 to CH 2 Common Mode Rejection Ratio CMRR Channel Isolation attenuation of deselected channel 2 mV Div to 0 5 V Div Trace Shift as VAR VOLTS DIV is Turned Invert Trace Shift Trace Shift Between VOLTS DIV Switch Positions PERFORMANCE REQUIREMENTS 45 596 5 or less 1096 10 10 or less Add 2 to all positive going step specifications Aberrations measured anywhere on screen do not exceed those measured at center screen by more than 1 Add 0 15 per C above or below 25 C Less than 400 ps difference At least 25 1 up to 10 MHz and at least 10 1 up to 100 MHz for signals of eight divisions or less with VOLTS DIV VAR adjusted for best CMRR at 50 kHz 10 MHz 50 db 2316 1 or more 100 MHz 34 dB 50 1 or more Channel isolation tested with eight division input signal 1 division or less 1 division or less 0 2 division or less 2246 1Y and 2246 Mod A Operators 6 3 Performance Characteristics Table 6 1 cent Electrical Characteristics CHARACTERISTICS PERFORMANCE REQUIREMENTS Trace Shift Between GND and DC input Coupling 10 C to 35 C Less than 0 5 mV 35 C to 55 C Less than 2 mV Input Characteristics Resistance 1 MO 2 2 Capacitance 20 pF 2 pF Capacitance Match Between Any Two VOLTS D
127. on generator X AXIS Bandwidth Connect the leveled sine wave generator SG 503 output to the CH 1 input via a 50 precision BNC coaxial cable and a 50 BNC termination Set VERTICAL MODE CH 2 CH 1 off CH 1 VOLTS DIV 10 mV Set leveled sine wave generator output for six divisions of 50 kHz sig nal Set leveled sine wave generator to 3 MHz CHECK X Axis display is 4 2 horizontal divisions or more Disconnect the test equipment from the 2246 1Y or 2246 Mod A 7 44 2246 1Y and 2246 Mod A Operators Performance Check Procedure TIME AND CURSORS MEASUREMENTS Equipment Required See Table 7 1 Time mark generator Calibration generator 50 BNC coaxial cable 50 BNC termination 1 lt SEC gt and je I SEC gt Cursor Accuracy a Set READOUT intensity For a viewable readout A INTEN For a viewable trace VERTICAL MODE CH 1 all others off CH 1 VOLTS DIV 0 5 v CH 1 and CH 2 Input COUPLING DC Horizontal MODE A A SEC DIV 1ms A B SELECT A Trigger TRIGGER MODE AUTO LEVEL TRIGGER CPLG DC TRIGGER SOURCE VERT TRIGGER SLOPE f positive going TRIGGER HOLDOFF Min CH 2 INVERT off SCOPE BW off FOCUS For best defined display b Connect time mark generator TG 501 output via a 50 BNC coaxial cable and a 50 BNC termination to the CH 1 input C Set time mark generator for 1 ms time marks d Position first time marker horizontally to the first vertical graticule line left most edge of the gr
128. ot have to remove the wrap around cabinet from the 2246 1Y or 2246 Mod A to do this procedure All checks can be made with controls and connectors accessible from the outside Test Equipment Required Table 7 1 lists all the test equipment required to do the Performance Check Procedure Test equipment specifications described are the minimum necessary to provide accurate results For test equipment operating In formation refer to the appropriate test equipment instruction manual When you use equipment other than that recommended you may have to make some changes to the test setups If the exact example equipment in Table 7 1 is not available use the Minimum Specification column to de termine if any other available test equipment might be adequate to do the check Performance Check Interval To ensure instrument accuracy check the performance of the 2246 1Y or 2246 Mod A after every 2000 hours of operation or once each year if used infrequently If the checks Indicate a need for readjustment or repair refer the instrument to a qualified service person NOTE The silver oxide batteries used in the 2246 1Y MUST BE REPLACED AT LEAST EVERY 12 MONTHS to ensure proper operation of the instrument 2246 1Y and 2246 Mod A Operators 7 1 Performance Check Procedure Preparation This procedure is divided into subsections to let you check individual sec tions of the instrument when it is not necessary to do the complete Performance Che
129. out and cursors can be set to turn on briefly at the end of the sequence when using a camera factory settings default mode or they can be set to remain on by changing the instrument configuration from the CONFIGURE menu see Service Menu Features in Section 3 B Trigger Modes AUTO LEVEL Sets the range of the Trigger LEVEL control to the peak to peak limits of an adequate B Trigger source signal and trig gers the B sweep NOTE The B sweep operates in RUNS AFTER mode when the trigger source signal amplitude is too low or the frequency is below 10 Hz Switch to NORM triggering if the repetition rate is too slow for autoleveling The A Sweep must be run ning free running or triggered for B Sweep to trigger Once set autoleveling is repeated only if triggering is lost if TRIGGER LEVEL control is rotated to either end stop or if AUTO LEVEL 2 14 2246 Y and 2246 Mod A Operators Controls Connectors and Indicators Trigger MODE is reselected AUTO LEVEL mode is useful for quickly locating an appropriate triggering level RUNS AFTER Starts the B sweep immediately after the delay time selected by the lt OR DELAY control The Trigger MODE must be in RUNS AFTER before timing measure ments can be selected when the Horizontal Mode is ALT or B A time measurement will be canceled if the Trigger MODE is changed from RUNS AFTER while in the ALT or B Horizontal Mode NORM The B sweep is triggered when an adequate trigger sign
130. phone number of a contact person type and serial number of the instrument reason for returning and a complete description of the service required Completely wrap the instrument with polyethylene sheeting or equivalent to protect the outside finish and keep harmful substances out of the instrument Cushion instrument on all sides with three inches of padding material or urethane foam tightly packed between the carton and the instrument Seal the shipping carton with an Industrial stapler or strapping tape If the instrument was NOT purchased under Air Force Contract No F41 608 88 D 0087 address the shipping carton to the nearest Tektronix Service Center Please include your own return address on the shipping carton If purchased under Air Force Contract No F41608 88 D 0087 this instrument is warranted for 5 years in accordance with the terms of said contract NOTE Special Instructions for instruments purchased under Air Force Contract No F41 608 88 D 0087 If the instrument IS still under warranty contact your local Tektronix Service Center for shipping instructions If the Instrument IS NOT under warranty address the shipping carton to the nearest Tektronix Service Center Please Include your own return address on the shipping carton Certificate of the Manufacturer Importer We hereby certify that the 2246 AN AND 2246 MOD A OSCILLOSCOPES AND ALL INSTALLED OPTIONS complies with the RF Interference Suppression
131. pulse width and or rise time measurements To set the Trigger LEVEL to the appropriate level with no signal applied or with GND Input coupling use the TRACK s cursor feature The TRACK sh cursor menu choice Is reached through the same menu path as the TRACK TRIG LVL cursor The ground cursor provides feedback to the user so that the ground level may be positioned without the need for a ground baseline trace DC SYMBOL Figure 5 11 Setting a specific trigger level 2246 1Y and 2246 Mod A Operators 523 Basic Applications Set the VOLTS DIV control so that the displayed signal will have a good viewing amplitude For the assumed signal shown in Figure 5 11 a setting of 1 V div will produce a four to five division display amplitude Position the ground cursor using the VERTICAL POSITION control at about three graticule divisions below the center graticule line For negative going signals two divisions above the center graticule would about center the display and for bipolar signals centering the ground trace is appropriate Zeroing the Trigger LEVEL control may be useful if the cursor is positioned out of the viewing area Simply switch the Input COUPLING of the selected channel to GND and switch the Trigger MODE to AUTO LEVEL Once zeroed set the Trigger MODE to NORM so that the Trigger LEVEL you set will be maintained If AUTO LEVEL is left on the Trigger LEVEL will continue to follow the applied signal ground in this case
132. quipment Required See Table 7 1 50 Precision BNC coaxial cable 50 Termination Adapter BNC male to miniature probe tip Dual input coupler For a viewable readout For a viewable trace CH 1 and CH 2 1v DC A TRIGGER AUTO LEVEL VERT DC positive going 12 o clock Min 12 o clock A 0 5 ms For best defined display All off press CLEAR DISPLAY three times off off b Set Vertical MODE to CH 1 CH 2 off c Connect calibration generator PG 506 STD AMPL output to the CH 1 input via a 50 BNC coaxial cable 2246 1Y and 2246 Mod A Operators Performance Check Procedure d Set calibration generator to STD AMPL and AMPLITUDE to 5 V e Position the bottom of the signal to the center horizontal graticule line f Set CH 1 Input COUPLING to AC g CHECK display is roughly centered about the center horizontal graticule line h Move the test signal to the CH 2 input i Set VERTICAL MODE to CH 2 CH 1 off 1 Repeat the procedure for 2 k Disconnect the test signal from the 2246 1Y or 2246 Mod A 2 CH 1 and CH 2 VOLTS DIV Trace Shift a Set CH 1 and CH 2 VERTICAL MODE On CH 1 and CH 2 VOLTS DIV 2 mV CH 1 and CH 2 Input COUPLING GND SCOPE BW On b Set VERTICAL MODE to CH 1 CH 2 off C Position trace to center horizontal graticule line d Switch CH 1 VOLTS DIV through all positions from 2 mV to 5 V e CHECK trace shift does not exceed 0 2 division between
133. r equiva lent to protect the outside finish and keep harmful substances out of the instrument 4 Cushion instrument on all sides with three inches of padding material or urethane foam tightly packed between the carton and the instrument 5 Seal the shipping carton with an industrial stapler or strapping tape 6 f the Instrument was NOT purchased under Air Force Contract No F41608 88 D 008 address the shipping carton to the nearest Tektronix Service Center Please include your own return address on the shipping carton NOTE Special instructions for instruments purchased under Air Force Contract No F41608 88 D 0087 If the instrument IS under warranty contact your local Tektronix Service Center for shipping instructions If the instrument IS NOT under warranty address the shipping car ton to the nearest Tektronix Service Center Please include your own return address on the shipping carton 2246 1Y and 2246 Mod A Operators REV AUG 1988 1 7 SECTION 2 CONTROLS CONNECTORS AND INDICATORS 2246 1Y and 2246 Mod A Controls Connectors and Indicators CRT Power and Display Refer to Figure 2 1 for location of items 1 through 9 1 Power Switch Turns on or off instrument power Press for ON or OFF At least one VERTICAL MODE button will light when the power is turned on The front panel setup existing when the power is turned off will return when the power is turned on again 2 INTEN Control Adjusts the brig
134. r maximum input voltage see Table 6 1 i This symbol indicates where applicable Symbols as Marked on Equipment DANGER High voltage za Protective ground earth terminal A ATTENTION Refer to manual 2246 1Y and 2246 Mod A Operators ix Power Source This product is intended to operate from a power source that does not ap ply more than 250 V rms between the supply conductors or between either supply conductor and ground A protective ground connection by way of the grounding conductor in the power cord is essential for safe operation Grounding the Product This product is grounded through the grounding conductor of the power cord To avoid electrical shock plug the power cord into a properly wired receptacle before making any connections to the product input or output terminals A protective ground connection by way of the grounding con ductor 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 Use the Proper Power Cord Use only the power cord and connector specified for your product The power cord must be in good condition Read Section 1 for power cord and connector information Use the Proper Fuse To avoid fire hazard use only a fuse of the correct type voltage rating and current rating as speci
135. r time measurements can be calibrated separately by selecting the SELF CAL Item from the VOLTMETER or TIME Measurement Menus NOTE CALIBRATE MEASUREMENTS or SELF CAL can be performed anytime after a 20 minute warmup to ensure the accuracy stated in Section 6 Internal Settings Menu The INTERNAL SETTINGS MENU see Figure 3 10 consists of MAKE FACTORY SETTINGS LOAD STORE RECALL STORED SETUPS and ADJUST VERTICAL OUTPUT All INTERNAL SETTINGS menu items except ADJUST VERTICAL OUTPUT are for use by the operator To return to the main SERVICE MENU press the up arrow key to underline INTERNAL SETTINGS MENU and press the button again to display the SERVICE MENU To return to the oscilloscope mode select QUIT from the INTERNAL SETTINGS MENU or SERVICE MENU or press the CLEAR DISPLAY button MAKE FACTORY SETTINGS Sets the front panel controls and menu con figurations as described In Appendix B LOAD STORE RECALL SETUPS This feature is not available on the 2246 1Y and 2246 Mod A oscilloscopes However if selected the message THIS WILL DELETE PREVIOUSLY STORED SETUPS CONTINUE ap pears Pressing either YES or NO has no effect on instrument operation ADJUST VERTICAL OUTPUT This menu item is to be used by a service technician during calibration and troubleshooting It is not an operational function 2246 1Y and 2246 Mod A Operators 3 28 Operators Familiarization INTERNAL SETTINGS MENU MAKE FACTORY SETTINGS 7 MENU LOAD
136. rements at 20 ns per div sweep speed are impractical due to imprecise definition of the inten sified zone at that sweep speed Peak Voltage Measurement make a peak voltage measurement use the following procedure Apply the signal to be measured to CH 1 input connector Set CH1 VOLTS DIV so that entire signal is on screen and POSITION Vertical MODE CH 1 Horizontal SEC DIV so that at least 1 cycle is displayed Horizontal MODE A Press the VOLTMETER CH1 CH2 button to call up the selection menu and select the PEAK choice Any of the page one choices may be Selected as required for the waveform measurement wanted Depending on the way the CONFIGURE choices of the SERVICE menu have been made the menu will either go off when the measurement selection is made or it will stay on If the menu remains on press the CLEAR DISPLAY button once to remove it from the display See the SERVICE Menu discussion in Section 3 for further details 5 2 2246 1Y and 2246 Mod A Operators 4 5 Basic Applications NOTE The TRACK MEASMT cursor may be displayed with the waveform Pressing CLEAR DISPLAY in the initial setup removes the measurement tracking cursor from the display and also can cels the measurement but does not disable the feature once it has been enabled the next time a CH 1 CH 2 Voltmeter measurement mode is called for the measurement tracking cursor is again displayed Press the CURSORS button and display page 2 of t
137. rements requiring the best possible accuracy Conditions for Cursors Display The following information is an aid in understanding the order in which the menu measurement cursors are displayed Measurement Cursors One or two measurement cursors may be displayed if any one of the fol lowing conditions is met VOLTMETER CH1 CH2 TRACK MEASMT is underlined and measure ment source channel is on and the VOLTS DIV VAR control in detent CURSOR VOLTS Measurement source channel must be on and VOLTS DIV VAR control in detent TIME Horizontal MODE is in A Track Trig Lvl Cursors If one or no measurement cursor is displayed one or two trigger level cur sors not more than two cursors total will be displayed if the following con ditions are met TRACK TRIG LVL is underlined TRIGGER SOURCE switch is In CH 1 or CH 2 The trigger source channel is displayed Trigger source channel VOLTS DIV VAR control is in detent 3 16 2246 1Y and 2246 Mod A Operators Operators Familiarization TRIGGER MODE switch is in AUTO LEVEL AUTO NORM or SGL SWP TRIGGER CPLG switch is in DC or NOISE REJ Horizontal MODE switch is in A ALT or B Track th Cursors If one or no measurement or trigger level cursor is displayed up to two ground cursors not more than two cursors total may be displayed if the following conditions are met TRACK 7 is underlined and CH 1 and or CH 2 VERTICAL MODE is selected Trigger source channel CH 1 a
138. requirements of Amtsbl Vfg 1046 1984 The German Postal Service was notified that the equipment is being marketed The German Postal Service has the right to re test the series and to verify that it complies TEKTRONIX Bescheinigung des Herstellers Importeurs Hiermit wird bescheinigt da der die das 2246 1Y AND 2246 MOD A OSCILLOSCOPES AND ALL INSTALLED OPTIONS in bereinstimmung mit den Bestimmungen der Amtsblatt Verfugting 1046 1984 funkentstort ist Der Deutschen Bundespost wurde das Inverkehrbringen dieses Gerates angezeigt und die Berechtigung zur Uberpruf ng der Serie auf Einhalten der Bestimmungen eingeraumt TEKTRONIX NOTICE to the user operator The German Postal Service requires that Systems assembled by the operator user of this instrument must also comply with Postal Regulation Vfg 1046 1984 Par 2 Sect 1 HINWEIS fur den Benutzer Betreiber Die vom Betreiber zusammengestellte Anlage innerhalb derer dies Ger t eingesetzt wird mu ebenfalls den Voraussetzungen nach Par 2 Ziff 1 der Vfg 1046 1984 genugen NOTICE to the user operator The German Postal Service requires that this equipment when used in a test setup may only be operated if the requirements of Postal Regulation Vfg 1046 1984 Par 2 Sect 1 7 1 are complied with HINWEIS f r den Benutzer Betreiber Dies Ger t darf in Mefaufbauten nur betrieben werden wenn die Voraussetzungen des Par 2 Ziff 1 7 1 der Vfg 1046
139. ress PHASE menu selection to display the PHASE 3 and SET 360 menu choices e Set le SET 360 on f Position the first time marker to first gratlcule line Then position the Reference cursor to the leading edge of the second time marker and the delta cursor to the leading edge of the tenth time marker SET le PHASE gt on h Position delta cursor to the leading edge of the sixth time marker CHECK that the readout Is between 177 9 and 182 1 degrees j Disconnect time mark generator 4 VOLTS Cursor Accuracy a Set CH 1 VOLTS DIV 0 1 v SEC DIV 0 5 ms CURSORS Menu On Ic VOLTS gt CURSORS On b Connect calibration generator PG 506 STD AMPL output to the CH 1 Input via a 50 Q precision BNC coaxial cable c Set calibration generator to STD AMPL and AMPLITUDE to 0 5 V d Position bottom of the signal to the second horizontal graticule line from the bottom 2246 1Y and 2246 Mod A Operators 7 47 Performance Check Procedure Position the reference cursor to the bottom of the signal and the delta cursor to the top of the signal both cursors move with the e OR DELAY control CHECK that the readout Is between 0 495 V and 0 505 V 5 sh VOLTS gt Cursor Accuracy o Select MEASUREMENTS CURSORS menu then select th VOLTS gt CURSORS Position the control to align the delta cursor with the top of the waveform CHECK that the readout is between 0 495 V to 0 505 V and none of th
140. s Normal Mode Rejection Ratio 7 51 3 Peak Peak and Peak Peak Volts Accuracy 7 52 4 25 MHz Peak Peak and Peak to Peak Volts 7 58 5 100 MHz Peak Peak and Peak to Peak Volts Accuracy cx rU mA ded ne bole Sox et dr e 7 58 6 Gated Volts 7 54 EXTERNAL Z AXIS AND PROBE ADJUST AND FRONT PANEL SETUP FUNCTIONS 1 Check External Z Axis 7 55 2 PROBE ADJUST 7 56 3 Run MAKE FACTORY SETTINGS Routine 7 56 2246 1Y and 2246 Mod A Operators 7 7 Performance Check Procedure DISPLAY Equipment Required See Table 7 1 Time mark generator 50 BNC termination 50 BNC coaxial cable 1 TRACE ROTATION a Set READOUT intensity A INTEN VERTICAL MODE CH 1 VOLTS DIV CH 1 COUPLING A B SELECT TRIGGER MODE TRIGGER SOURCE TRIGGER CPLG TRIGGER SLOPE TRIGGER HOLDOFF TRIGGER LEVEL Horizontal MODE Horizontal POSITION A SEC DIV Measurements FOCUS SCOPE BW For a viewable readout For a viewable trace CH 1 0 1 v AC A Trigger AUTO LEVEL VERT DC _ positive going Min 120 clock A 120 clock 2 us All off press CLEAR DISPLAY three times For best defined display off b Position trace vertically to the center graticule line CHECK trace rotation control range Is adequate to align trace
141. s a last measure ment mode the peak voltages of the source channel signal are measured and one cursor is placed at the most positive peak and the other is placed at the most negative peak th VOLTS A Measures the equivalent voltage between cursor and ground Marks the ground position of the selected waveform display in either A Horizontal MODE or X Y Horizontal MODE The ground cursor follows the ground level of the source channel waveform as it is positioned vertically TO AUTO TRACKING MENU Selects CURSORS measurement page 2 choices All of the tracking cursor selections may be underlined but only two cursors of either type tracking or measurement may be displayed at a time If TRACK MEASMT is selected and a Channel 1 or Channel 2 Voltmeter measurement is active the TRACK 77 cursor is not displayed when TRACK TRIG LVL is also active If the measurement tracking cursor is turned off the ground tracking cursor will return to the display 2246 1Y and 2246 Mod A Operators 3 11 Operators Familiarization CURSOR VOLTS He VOLTS VOLTS gt TO AUTO TRACKING MENU CURSORS PG 2 TRACK MEASMT TRACK TRIG LVL TRACK BACK TO PREVIOUS MENU MENU OFF 7061 05 Figure 3 6 Cursors measurements menus 3 12 2246 1Y and 2246 Mod A Operators Operators Familiarization The CLEAR DISPLAY button may be used to turn off the MENU MEASUREMENT and TRACK TRIG LVL and TRACK cursors in a priority scheme of thre
142. setting in A Horizontal MODE to display at least one complete reference waveform period and no more than two if pos sible An excessive number of cycles of the reference waveform in the display reduces the users ability to make an accurate reference set ting Triggering on the negative slope of the sine wave may position the waveform correctly within the graticule area for ease in measurement when viewing a single cycle of the reference signal 5 Press the TIME button to display the measurement choices 5 14 2246 1Y and 2246 Mod A Operators 13 Basic Applications Select e PHASE 34 A second level phase measurement menu is then displayed with two choices one to continue the phase measurement and one to set the 360 degree reference Assume the present reference setting is not correct if it were selecting l PHASE again continues the measurement using the present reference value Press ie SET 360 34 to activate the reference setting function The position of the displayed cursors when e PHASE is again selected defines the full waveform period 360 degrees Position the first vertical cursor to the point that the reference waveform crosses the center horizontal graticule line in the positive direction see Figure 5 8A The Horizontal POSITION control may be used as necessary to center the waveform period in the viewing area Position the delta cursor to the second positive crossing of the center horizontal gr
143. sitivity 7 34 TV Line Trigger Sensitivity 0 0 0 0000000020000 7 34 Line Trigger Functional 7 35 2246 1Y and 2246 Mod A Operators Performance Check Procedure HORIZONTAL 1 and B Sweep Length 2 2 22m nme nenn 7 36 2 Horizontal POSITION 7 37 VAR SEC DIV 7 37 4 Magnifier 7 38 5 A and B Timing Accuracy and 7 38 6 A and B Magnified Timing Accuracy 7 40 7 Delay Time Jitter 7 41 8 Delay Time Accuracy 7 41 9 Delay Time Position 7 42 10 X Axis Gain 7 43 11 X Y Phase 7 43 12 X Axis 7 44 TIME AND CURSORS MEASUREMENTS 1 le SEC gt and e 1 SEC Cursor 7 45 2 Delta Time Accuracy 7 46 3 K PHASE Cursor 7 47 4 K VOLTS X Cursor 7 47 5 d VOLTS Cursor 7 48 6 Tracking Cursors Position Accuracy 7 48 CH1 CH2 VOLTMETER MEASUREMENTS 1 Volts Accuracy u us cR eR my Oe es 7 50 2 DC Volt
144. ss the TIME button then select the SEC gt menu choice This produces two Intensified zones on the A Sweep trace and two alternate B Delay Sweeps Use the TRACE SEP and VERTICAL POSITION 2246 1Y and 2246 Mod A Operators 5 17 Basic Applications controls to position the B Delay Sweeps vertically in the graticule area for ease of viewing the separate traces 6 Use the SET MEAS MT CHANNEL menu choices to select the desired channels to make the time measurements on NOTE When making delay measurements between two different signals for time or phase difference the SET MEAS MT CHANNEL choices must be set to the correct measurement source channel to obtain the desired measurement results BOTH delays must be set to the same channel source for making period pulse width or rise time and fall time measurements If only a single channel is selected for display both delays will default to that channel If a channel is selected as a measurement source it will be turned on if not already on but it will not be turned off when deselected as a measurement source Extra display channels must be turned off using the VERTICAL MODE buttons if a channel is displayed but not selected as a measurement source that waveform trace will not be intensified and no alternate B Delayed trace will be displayed for that channel 7 Set the OR DELAY control so that the reference delay Intensified zone is positioned at the first point of interest po
145. steps f Set VERTICAL MODE to CH 2 CH 1 off g Position CH 2 trace to the center horizontal graticule line h Switch CH 2 VOLTS DiV through all positions from 2 mV to 5 V i CHECK trace shift does not exceed 0 2 division between steps 2246 1Y and 2246 Mod A Operators 7 11 Performance Check Procedure 3 CH 3 and CH 4 VOLTS DIV Trace Shift a Set VERTICAL MODE to CH 3 CH 2 off b Position trace to the center horizontal graticule line c Switch CH 3 VOLTS DIV between 0 1 V and 0 5 V d CHECK trace shift does not exceed one division e Set VERTICAL MODE to CH 4 CH 3 off f Position trace to the center horizontal graticule line g Switch CH 4 VOLTSIDIV between 0 1 V and 0 5 V h CHECK trace shift does not exceed one division 4 CH 1 and CH 2 VAR VOLTSIDIV Trace Shift a Set VERTICAL MODE CH 1 CH 4 off CH 1 VOLTS DIV 2 mV b Position trace to center graticule line c Set CH 1 VAR VOLTS DIV fully CCW d CHECK trace shift does not exceed one division e Set CH 1 VAR VOLTSIDIV Detent calibrated VERTICAL MODE CH 2 CH 1 off CH 2 VOLTS DIV 2 mV f Position trace to center graticule line g Set CH 2 VAR VOLTS DIV fully CCW h CHECK trace shift does not exceed one division i Set CH 2 VAR VOLTS DIV to detent calibrated position 7 12 2246 1Y and 2246 Mod A Operators Performance Check Procedure 5 CH 1 and CH 2 Input COUPLING Trace Shift a Position trace to center graticule line b
146. sweep speed cannot be set slower than the A sweep speed attempting to do so forces the A sweep speed io follow the B sweep speed To increase the A sweep speed in the ALT MODE set the Horizontal MODE to A adjust the SEC DIV switch to a faster A sweep setting and reset the Horizontal MODE switch to ALT The B sweep speed and the length of the intensified zone are determined by the B SEC DIV switch setting B Select B sweep horizontal deflection The B sweep speed is determined by the B SEC DIV switch setting as displayed in the crt readout Whenever B MODE is selected the A B SELECT switch is set to B Trigger The start of the B sweep in RUNS AFTER mode or the arming of the B Trigger in any triggered mode is delayed from the start of the A sweep by a time determined by the setting of the OR DELAY control The B SEC DIV switch setting and the Delay Time Position setting are displayed In the crt readout A greater than sign is displayed in front of the Delay Time readout if the B Trigger MODE is not RUNS AFTER X Y The signal applied to CH 1 OR X input connector produces the horizontal X Axis deflection Signals applied to any vertical input connector or ADD may be selected to provide the vertical deflection Y Axis The X Y displays are horizontally positioned by the Horizontal POSITION control and vertically positioned by the associated vertical channel POSITION control A AND B SEC DIV Switch Selects the horizontal defl
147. ter horizontal graticule line m Set CH 2 POSITION to 12 o clock n Move the BNC dual input coupler from the CH 1 and CH 2 inputs to the CH 3 and CH 4 inputs Set VERTICAL MODE CH 3 CH 2 off CH 3 and CH 4 VOLTS DIV 0 1 v CH 3 POSITION Fully CW p CHECK that the bottom of the waveform Is above the center graticule line q Set CH 3 POSITION fully CCW r CHECK that the top of the waveform is below the center graticule line s Set CH 3 POSITION 12 o clock VERTICAL MODE CH 4 CH 3 off 7 18 2246 1Y and 2246 Mod A Operators 13 14 Performance Check Procedure Repeat the procedure for CH 4 Set CH 4 POSITION to 12 o clock Disconnect the test setup from the 2246 1Y or 2246 Mod A CH 1 to CH 2 Signal Delay Match Set VERTICAL MODE CH 1 and CH 2 CH 4 off CH 1 and CH 2 Input COUPLING DC CH 1 and CH 2 VOLTS DIV 0 1 v SEC DIV 20 ns TRIGGER SOURCE CH 3 Superimpose the CH 1 and CH 2 traces at the 100 graticule marking Connect calibration generator PG 506 FAST RISE rising edge signal to the CH 1 and CH 2 inputs via a 50 0 precision BNC coaxial cable a 50 BNC termination and a BNC dual input coupler Connect calibration generator TRIG OUT signal to the CH 3 input via a 50 BNC coaxial cable and a 50 BNC termination Set the calibration generator to FAST RISE and adjust PULSE AMPLI TUDE for five divisions of signal amplitude at 1 MHz Position the rising edges of the sup
148. the Trigger LEVEL control range to the peak to peak amplitude of the trigger source signal 2246 Y and 2246 Mod A Operators Controls Connectors and Indicators 36 Buttons Up and Down Arrows and Indicators Select the operating modes of the A and B trigger systems Pressing the Up Down Arrow buttons selects the operating modes as shown by the TRIGGER MODE lights Selections available for the A Trigger A B SELECT button lit are AUTO LEVEL AUTO NORM TV LINE TV FIELD and SGL SEQ Selections for the B Trigger A B SELECT button not lit are AUTO LEVEL RUNS AFTER NORM TV LINE FROM A SOURCE A Trigger Modes AUTO LEVEL Automatically sets the range of the Trigger LEVEL control to the peak to peak limits of an adequate A Trigger source signal and triggers the sweep Autoleveling is repeated if triggering is lost If the TRIGGER LEVEL control is rotated to either end stop or if AUTO LEVEL TRIGGER MODE is selected again AUTO LEVEL mode is useful for quickly locating and maintaining an appropriate triggering level NOTE The A sweep free runs to produce a baseline trace when the A trigger source signal amplitude is too low or the frequency is below 10 Hz Switch to NORM triggering if the repetition rate is too slow for autoleveling AUTO Triggers the same as the NORM Trigger MODE when an ade quate trigger signal is applied However the A sweep free runs to display a baseline trace when there is no trigger signal
149. the adjustment procedure Vertical Check The PROBE ADJUST square wave signal may be used to check the Channel 1 and Channel 2 vertical deflection system in the following procedure 1 Perform Initial Setup procedure Connect the two 10X probes supplied to the CH 1 and CH 2 input connectors 2 Connect both probe hook tips to the PROBE ADJUST connector 4 4 2246 1Y and 2246 Mod A Operators Operator Checks and Adjustments Set CH 1 amp CH 2 COUPLING DC VERTICAL MODE CH 1 Horizontal MODE A A SEC DIV 0 5 ms Set CH 1 and CH 2 VOLTS DIV switches to 0 1 V for the attached 10X probes Set the bottom of the trace of the PROBE ADJUST square wave signal to a convenient horizontal graticule line with the Vertical POSITION control Check for a five division display of the PROBE ADJUST square wave signal Select CH 2 VERTICAL MODE and repeat steps 6 and 7 Disconnect the probes from the Instrument Timing Checks The time measurement cursors may be used to check the horizontal deflection system 1 Preset instrument controls and obtain a baseline trace and set the A SEC DIV switch to 0 1 ms Vertically center the baseline trace Press the TIME button to call up the Time Measurement Mode menu on the crt and select t SEC function for measuring time difference by pressing the Menu Select button opposite menu label Align the reference cursor to the second vertical graticule line using the OR
150. the following order CH 1 CH 2 CH 3 CH 4 and ADD AUTO CH 2 The signal applied to the CH 2 input connector is the source of the trigger signal CH 3 The signal applied to the CH 3 input connector is the source of the trigger signal CH 4 The signal applied to the CH 4 input connector is the source of the trigger signal LINE The triggering signal is obtained from a sample of the ac power source waveform This trigger source is useful when the dis played waveform frequency is time related to the ac power source frequency 38 cPLe Up Arrow and Down Arrow Buttons and Indicators Select the method of coupling the input trigger signal to the A or B trigger system as directed by the A B SELECT button Pressing the Up Down Arrow buttons selects the trigger coupling as shown by the CPLG lights 2 16 2246 Y and 2246 Mod A Operators Controls Connectors and Indicators DC Couples dc and all frequency components of a triggering signal to the trigger circuitry DC coupling is useful for most signals but it is especially useful for providing a stable display of low frequency or low repetition rate signals NOISE REJ Noise Reject Couples all frequency components of the input signal to the trigger circuitry but increases the peak to peak signal amplitude required to produce a trigger event NOISE REJ coupling is useful for improving stability when the trigger signal is accompanied by low level noise HF REJ High
151. the second point on the waveform and read the voltage difference Ground Referenced Voltage Voltage measurements using ground as a reference are made using the th VOLTS cursors The ground tracking cursor is fixed at the ground level of the applied signal and the independent cursor above or below ground as necessary to measure the voltage at the cursor position Use the following procedure to set up ground referenced voltage measurements 1 Apply the signal to the input connector s 2 Set Vertical MODE As desired CH 1 and or CH 2 so that entire signal Ison screen VOLTS DIV and POSITION CH 1 CH 2 COUPLING DC Horizontal SEC DIV So that at least 1 cycle Is displayed Horizontal MODE A 5 8 2246 1Y and 2246 Mod A Operators Basic Applications 3 Press the CURSORS button to display the measurement selection menu and select the s VOLTS cursors The independent cursor is initial ized to the PEAK of the Input waveform 4 Position the independent cursor using the control to the measure ment point on the waveform and read out the value of the cursor position shown in Figure 5 4 The k OR DELAY control has no effect NOTE The test signal used for illustration purposes in Figure 5 4 is a video test signal For triggering on a video waveform select TV LINE Trigger COUPLING and negative _ Trigger SLOPE for other signal types no change of COUPLING or SLOPE is required MOVABLE CURSOR GROUND CURSOR
152. ting of 0 5 V the voltage applied to that channel should not exceed 4 V c Use CH 1 and CH 2 POSITION control settings which most nearly position the signal on each channel to mid screen when viewed separately This ensures the greatest dynamic range for ADD mode signal displays d To have similar responses for both channels use the same Input COUPLING for both CH 1 and CH 2 The following procedure shows how to eliminate an unwanted ac input power frequency signal component from the displayed signal a Perform the Initial Setup in OPERATOR CHECKS AND ADJUST MENTS Section 4 and center the baseline trace vertically b Apply the signal of interest containing the unwanted line frequency component to the CH 1 input connector c Apply a line frequency signal to the CH 2 input connector To maxi mize cancellation the signal applied to the CH 2 input must be exactly in phase or exactly 180 out of phase with the frequency component to be canceled from the CH 1 signal 2246 1Y and 2246 Mod A Operators 5 25 Basic Applications d Select CH 1 and CH 2 VERTICAL MODE e Set TRIGGER SOURCE switch to VERT f Set both VOLTS DIV switches to produce displays of about two or three divisions in amplitude g Adjust the CH 2 VOLTS DIV switch and VAR control so that the 5 26 CH 2 display is about the same amplitude as the component to be canceled in the CH 1 waveform see Figure 5 1 2A CH 1 SIGNAL WITH
153. tions 7 22 SCOPE BW Bandwidth Limit Accuracy 7 22 Common mode Rejection Ratio 7 23 Channel Isolation mE 7 24 AC Coupled Lower 3 dB 7 25 Vertical ALT and CHOP Modes 7 26 BEAM FIND Functional Check 7 26 and B Trace Separation 7 27 TRIGGERING es ur Sore turn dO Se mE ere 7 28 500 Hz Trigger 5 7 28 500 kHz Trigger 5 7 29 25 MHz Trigger 5 5 7 30 100 MHz Trigger 5 7 31 100 MHz NOISE REJ Trigger Sensitivity 7 32 Single Sweep Mode 7 32 Trigger LEVEL Control 7 33 TV Field Trigger 5 5 7 34 TV Line Trigger 5 7 34 Line Trigger Functional 7 35 HORIZONTAL 37 PE ca Ne s 7 36 and B Sweep 7 36 Horizontal POSITION 7 37 VAR SEC DIV 7 37 Magnifier Registration llle 7 38 and B Timing Accuracy and Linearity 7 38 A and B Magnif
154. tor from the test signal path Set leveled sine wave generator output for a 2 2 division display amplitude at 100 MHz CHECK that the display is stably triggered with NOISE REJ Trigger CPLG Page 1 of 1
155. ut of any Peak or Peak to Peak voltage measurement 2246 1Y and 2246 Mod A Operators 2 5 Controls Connectors and Indicators NOTE When AC Coupling is selected for DC voltmeter measure ments an error message SELECT DC COUPLING is displayed DC Couples dc and all frequency components of the input signal to the vertical attenuator when the DC button is lit Turning on DC coupling turns off AC coupling With DC Coupling selected a DC symbol is displayed to the right of the associ ated VOLTS DIV readout Input resistance Is 1 Mf to ground Refer to Figure 2 3 for location of items 18 through 23 18 CH 1 OR X and CH 2 Input Connectors Connect signals to the inputs of Channel 1 and Channel 2 vertical attenuators Input connectors are BNC type with an outer contact ring for recog nizing attenuation factors of coded attenuator probes A signal con nected to the CH 1 OR X input connector produces the horizontal deflection X Axis in the X Y horizontal mode Any of the vertical signal channels or ADD can provide vertical deflection Y Axis for an X Y display coupunc LJ LJ Bram ro Mac OMA i j Sonn dr wei ur AME 2 0200 4009 2007 400V pk MN 209F 5 400V pk 209 s 400v 6558 05 Figure 2 3 Vertical connectors and CH 3 and CH 4 controls 2 6 2246 Y and 2246 Mod A Operators Controls Connectors and Indicators PROBE ADJUST Connector Outputs a 0 5
156. vides the most convenient way to connect an input signal to the oscilloscope The standard 10X probes supplied with the 2246 1Y and 2246 Mod A are shielded against electromagnetic interference and have a high input impedance for low circuit loading The subminiature probe bodies are designed for probing circuitry with closely spaced leads SCALE FACTOR SWITCHING The VOLTS DIV scale factors displayed on the crt reflect the probe attenuation factor when Tektronix coded probes are used OPERATING CONSIDERATIONS To get the best waveform fidelity keep probe ground and signal leads as short as possible Misadjusted probe compensation can cause measurement error Check and adjust probe compensation whenever a probe Is moved to a different channel or oscilloscope For the probe compensation adjustment pro cedure see Section 4 Operator Checks and Adjustments For detailed operating considerations and probe maintenance see the instruction sheet supplied with the probe Coaxial Cables Signal input cable can greatly affect the accuracy of a displayed waveform To maintain original frequency characteristics of the input signal use only high quality low loss coaxial cables Coaxial cables must be terminated at both ends in their characteristic impedance to prevent signal reflections within the cable Use suitable Impedance matching devices External Triggering Any of the four vertical channels in the 2246 1Y and 2246 Mod A can be used as
157. with center graticule line using a small straight bladed alignment tool 7 8 ADJUST trace parallel to center horizontal graticule line 2246 1Y and 2246 Mod A Operators Performance Check Procedure 2 Geometry a Connect time mark generator TG 501 to CH 1 via a 50 BNC coaxial cable and a 50 BNC termination b Set generator for 0 2 uS time marks Position the bottom of the CH 1 signal below the bottom graticule line d CHECK devlatlon of any vertical line within the center eight horizontal divisions does not exceed 0 1 division half a minor division e Set CH 1 COUPLING to GND f Positlon trace slowly from the bottom graticule line to the top graticule line while making the following check g CHECK bowing or tilt of baseline trace doesn t exceed 0 1 division half a minor division within the eight vertical divisions h Disconnect test signal from the 2246 1Y or 2246 Mod A 2246 1Y and 2246 Mod A Operators 7 9 Performance Check Procedure VERTICAL Leveled sine wave generator Calibration generator Function generator 50 BNC coaxial cable 1 Input COUPLING Functional Check a Set READOUT Intensity A INTEN VERTICAL MODE CH 1 and CH 2 VOLTS DIV CH 1 and CH 2 Input COUPLING A B SELECT TRIGGER MODE TRIGGER SOURCE TRIGGER CPLG TRIGGER SLOPE TRIGGER LEVEL TRIGGER HOLDOFF Horizontal POSITION Horizontal MODE SEC DIV FOCUS Measurements SCOPE BW CH 2 INVERT E
158. within 0 5 division of the center of a magnified sweep display No action occurs in X Y mode When X10 MAG is on a X10 symbol is displayed next to the SEC DIV readouts The readouts reflect correct display sweep speeds for the X10 MAG displays and the unmagnified displays 2246 1Y and 2246 Mod A Operators 2 7 Controls Connectors and Indicators a gt 24 d ZTIME POSITION lt OR DELAY 6858 06 7061 03 Figure 2 4 Horizontal controls and indicators MODE Buttons Up Arrow and Down Arrow and Indicators Select the operating mode of the horizontal deflection system Pres sing the Up Down Arrow buttons selects the horizontal deflection mode as shown by the MODE lights Not all Menu Measurement modes are compatible with all horizontal deflection modes See Table 3 1 Behavior for Horizontal MODE Changes in Section 3 A Selects A sweep horizontal deflection The A sweep speed is determined by the A SEC DIV switch setting as displayed in the crt 2 8 2246 Y and 2246 Mod A Operators Controls Connectors and Indicators readout Whenever A MODE is selected the A B SELECT switch is set to A Trigger ALT Alternates between A sweep with an intensified zone repre senting B sweep and B delayed sweep Both A and B SEC DIV switch settings are displayed in the crt readout but only the B can be adjusted Whenever ALT MODE is selected the A B SELECT switch is set to B Trigger The B

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