Tektronix 7B87 Generator
Manufacturer:
Model:
7B87
Date:
1986
Category:
Group:
Description:
Time Base Unit

Information

7B87 FEATURES The 7B87 Time-Base unit Pretrigger Acquire Clock provides calibrated sweep rates from 5 seconds lo 10 nanoseconds and triggering to 400 megahertz (or 7000 Series Oscilloscopes A X10 Magnifier increases each sweep rate by a factor of 10 and a VARIABLE TIME/ DIV control provides continuously-variable sweep rates between calibrated steps Variable holdoff and alphanumeric readout are provided Also, when operating in the AUTO TRIGGERING MODE, a bright baseline trace is displayed in the absence of a trigger signal The 7B87 can be operated as an independent time base or as a delayed-sweep unit with a companion delaying time-base unit Sweep mode is determined by the companion delaying time base The 7B87 also features an internally-generated clock and an external clock input for sequential single sweep acquisition when operating in a 7000 series digitizing Oscilloscope The frequency range of the internally generated clock is 20 48 mHz (millihertz) to 20 48 MHz as determined by the TIME DIV. X10 MAG. and INT - 1000 switches Also, an ACOUIRE-STOP DELAY function varies delay pickoff. and therefore pretrigger time, in compatible digitizing Plug-In oscilloscopes The portion of the Oscilloscope real time display between the triggering event and the end of delay time is intensified The exact delay time is displayed on the crt readout

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Service and User Manual
Manual type:
Service and User Manual
Pages:
128
Size:
35.97 Mbytes (37721496 Bytes)
Language:
english
Revision:
revised
Manual ID:
070-2788-00
Date:
1986 01 01
Quality:
Scanned document, all readable.
Upload date:
2017 04 23
MD5:
2a489022bb49891e6c5d6778b7c8569b
Downloads:
909

Information

PAGE PAGE LIST OF ILLUSTRATIONS ... iii LIST OF TABLES ... iv OPERATORS SAFETY SUMMARY ... v SERVICING SAFETY SUMMARY ... vii SECTION 1 OPERATING INSTRUCTIONS INSTALLATION ... 1-1 CONTROLS. CONNECTORS. AND INDICATORS ... 1-1 FUNCTIONAL CHECK ... 1-1 SETUP PROCEDURE ... 1-1 SWEEP FUNCTIONS ... 1-4 TRIGGERING FUNCTIONS ... 1-4 PRETRIGGER ACQUIRE CLOCK FUNCTIONS ... 1-5 GENERAL OPERATING INFORMATION ... 16 TRIGGERING SWITCH LOGIC ... 1-6 TRIGGERING MODES ... 1-6 TRIGGER COUPLING ... 1-9 TRIGGER SOURCE ... 1-9 TRIGGER SLOPE ... 1-11 TRIGGER LEVEL ... 1-11 HORIZONTAL SWEEP RATES ... 1-11 TIME MEASUREMENT ... 1-11 SWEEP MAGNIFICATION ... 1-11 VARIABLE HOLD OFF ... 1-12 MAINFRAME OPERATING MODES ... 1-12 APPLICATIONS ... 1-12 TIME INTERVAL MEASUREMENTS ... 1-12 RISE-TIME AND FALL-TIME MEASUREMENTS .. 1-13 PULSE WIDTH MEASUREMENTS ... 1-14 SECTION 2 SPECIFICATION STANDARD Accessories ... 2-4 THE REMAINING PORTION OF THIS TABLE OF CONTENTS LISTS SERVICING INSTRUCTIONS. THESE SERVICING INSTRUCTIONS ARE FOR USE BY QUALIFIED PERSONNEL ONLY. TO AVOID ELECTRICAL SHOCK. DO NOT PERFORM ANY SERVICING OTHER THAN THAT CALLED OUT IN THE OPERATING INSTRUCTIONS UNLESS QUALIFIED TO DO SO. SECTION 3 -THEORY OF OPERATION BLOCK DIAGRAM DESCRIPTION ... 3-1 TRIGGER Generator ... 3-1 SWEEP Generator ... 3-1 PICKOFF Amplifier AND DELAY GATE Generator ... 3 1 LOGIC ... 3-1 DIGITAL VOLTMETER ... 3-1 CLOCK Generator ... 3-1 DETAILED CIRCUIT DESCRIPTION ... 3-1 FRONT-PANEL DISTRIBUTION ... 3-3 TRIGGER Generator ... 3-3 EXTERNAL SOURCE ... 3-3 INTERNAL AND UNE SOURCE ... 3-3 TRIGGER SOURCE SELECTOR AND AMPLIFIER ... 3-3 PEAK TO-PEAK AUTO ... 3-3 SLOPE SELECTOR AND TRIGGER Generator ... 3 5 GATE Generator ... 3-5 LOGIC ... 3-5 SWEEP MODES ... 3-5 HOLD OFF TIMING ... 3-6 LOCKOUT BUFFER Amplifier ... 3-7 HOLD OFF OUTPUT Amplifier ... 3-7 SWEEP Generator ... 3-7 TIMING Current source ... 3-7 RAMP Generator ... 3 10 HORIZONTAL PREAMPLIFIER ... 3-10 SWEEP GATE Generator ... 3-10 DVM ... 3-10 DELAY TIME COMPARATOR AND DELAY GATE Generator ... 3-10 DIGITAL VOLTMETER ... 3-11 DELAY COMPARISON VOLTAGE TO RAMP CONVERTER ... 3-12 COMPARATOR ... 3-12 REFERENCE Current source ... 3-12 REFERENCE CURRENT INVERTER ... 3-12 Counter AND ENCODER ... 3-12 CLOCK Generator ... 3-12 CONTROL LOGIC ... 3-13 Oscillator ... 3-13 FIRST DIVIDER ... 3-15 XT XTO MULTIPLEXER ... 3-15 DECADE DIVIDER ... 3-15 INTERNAL CLOCK MULTIPLEXER ... 3-15 OUTPUT CLOCK MULTIPLEXER ... 3-15 INTENSIFY CIRCUIT ... 3-15 7B87 IN A HORIZ PLUG IN COMPARTMENT ... 3 16 INTERNAL BUTTON PRESSED ... 3-16 7B87 IN B HORIZ Plug-In COMPARTMENT ... 3-16 INTERNAL BUTTON PRESSED ... 3 16 TIME DIVISION AND READOUT SWITCHING ... 3-17 BASIC READOUT SYSTEM ... 3 17 TIME DIVISION READOUT ... 3-17 ACQUIRE-STOP DELAY TIME READOUT ... 3-17 Interface CONNECTIONS AND POWER SUPPLY ... 3-17 SECTION 4 MAINTENANCE PREVENTIVE MAINTENANCE ... 4 1 CLEANING ... 4 1 EXTERIOR ... 4-1 INTERIOR ... 4 1 SWITCH CONTACTS ... 4 1 ... 4-1 LUBRICATION ... 4-1 CAM SWITCH LUBRICATION ... 4-2 SEMICONDUCTOR CHECKS ... 4-2 ADJUSTMENT AFTER REPAIR ... 4-2 TROUBLESHOOTING ... 4-2 TROUBLESHOOTING AIDS ... 4-2 DIAGRAMS ... 4-2 VOLTAGES AND WAVEFORMS ... 4-2 CIRCUIT-BOARD ILLUSTRATIONS ... 4-2 SWITCH CAM IDENTIFICATION ... 4-4 DIODE COLOR CODE ... 4-4 WIRING COLOR CODE ... 4-4 SEMICONDUCTOR LEAD CONFIGURATIONS ... 4-4 INTER-BOARD PIN CONNECTOR IDENTIFICATION ... 44 MULTI-PIN CONNECTOR IDENTIFICATION ... 4-4 Interface CONNECTOR PIN LOCATIONS ... 4 5 PERFORMANCE CHECK AND ADJUSTMENT ... 4-5 STATIC SENSITIVE DEVICES ... 4 5 TROUBLESHOOTING EQUIPMENT ... 4-6 TROUBLESHOOTING TECHNIQUES ... 4-6 TROUBLESHOOTING PROCEDURE ... 4-6 CORRECTIVE MAINTENANCE ... 4-8 OBTAINING REPLACEABLE PARTS ... 4-8 SOLDERING TECHNIQUES ... 4-9 COMPONENT REMOVAL AND REPLACEMENT ... 4-10 CIRCUIT BOARDS ... 4 10 SWITCHES ... 4-12 SEMICONDUCTORS ... 4 15 INTERCONNECTING PINS ... 4-15 CIRCUIT BOARD PINS ... 4 15 FRONT-PANEL LIGHTS ... 4-16 ADJUSTMENT AFTER REPAIR ... 4 16 INSTRUMENT REPACKAGING ... 4 16 SECTION 5 PERFORMANCE CHECK ANO ADJUSTMENT PRELIMINARY INFORMATION ... 5-1 ADJUSTMENT INTERVAL ... 5-1 Tektronix FIELD SERVICE ... 5 1 USING THIS PROCEDURE ... 5-1 TEST EQUIPMENT REQUIRED ... 5-1 SPECIAL FIXTURES ... 5 1 TEST EQUIPMENT ALTERNATIVES ... 5 1 INDEX TO PERFORMANCE CHECK AND ADJUSTMENT PROCEDURE ... 5 4 PRELIMINARY PROCEDURE ... 5-4 A TRIGGERING SYSTEM ... 5-5 B HORIZONTAL/AQS SYSTEM ... 5-10 SECTION 6-INSTRUMENT OPTIONS SECTION 7 REPLACEABLE ELECTRICAL PARTS SECTION 8 DIAGRAMS AND CIRCUIT BOARD ILLUSTRATIONS SECTION 9 REPLACEABLE MECHANICAL PARTS CHANGE INFORMATION

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