Tektronix 11A52 User manual

TEK
Service
-----------------------Manual
11A52
Extended Service
C OMMITTED TO EXCELLENCE

TEK
EXTENDED SERVICE
MANUAL
Part No. 070-7391-99
Product Group 47
11A52
Two Channel Amplifier
Extended Service Manual
First Printing NOV 1988
WARNING
The following servicing instructions are for use by qualified
personnel only. To avoid personal injury, do not perform any
servicing unless you are qualified to do so.
Refer to the Safety
Summary prior to performing any service. ·
Please check for CHANGE INFORMATION at the rear of this manual.
Serial Number
----------
lektron~
COMMITTED TO EXCELLENCE

INSTRUMENT SERIAL NUMBERS
Each instrument manufactured by Tektronix has a serial number on a panel insert, tag, or stamped on the chassis.
The first letter in the serial number designates the country of manufacture. The last five digits of the serial number
are assigned sequentially and are unique
to each instrument. Those manufactured in the United States have six
unique digits. The country
of manufacture is identified as follows:
B010000
G100000
E200000
J300000
H700000
Tektronix, Inc. Beaverton, Oregon, USA
Tektronix Guernsey, Ltd., Channel Islands
Tektronix United Kingdom, Ltd., London
Sony/Tektronix, Japan
Tektronix Holland,
NV, Heerenveen, The Netherlands
Instruments manufactured for Tektronix
by external vendors outside the United States are assigned a two digit al-
pha code to identify the country of manufacture (e.g., JP for Japan, HK for Hong Kong, etc.).
Tektronix, Inc., P.O. Box 500, Beaverton, OR 97077
Copyright© Tektronix; Inc., 1988. All rights reseNed. Tektronix products are covered by U.S. and foreign patents,
issued and pending. TEKTRONIX, TEK., SCOPEMOBILE and
~ are registered trademarks.
~
TEKPROBE ® is a registered trademark of Tektronix, Inc.
Printed in U.S.A.

Contents
List of Illustrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
List
of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi
Safety Summary ................................................................................... vii
Section 1- General Information
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Amplifier-to-Oscilloscope Compatibility
........................................................ 1-1
Initial Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Installing and Removing
the 11A52 Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Oscilloscope Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Packaging for Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Operating
Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Section 2-Theory of Operation
Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Input Attenuators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-4
Attenuators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Calibrate/Normal (#1 relay) ................ , ........................................ 2-4
AC/DC Coupling (#2 relay) . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
lOX/lX (#3 relay) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
lOX/lX (#4 relay) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Attenuator States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
DC .............................................................................. 2-5
Off .............................................................................. 2-5
AC .................................................... ; ......................... 2-5
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Input Overload Sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Fuse Check Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Relay Fast Power On (RFPO) ............................................................ 2-6
Kernel
..................................................................................... 2-7
Analog Control Voltage System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2- 7
Analog-to-Digital Converter
............................................................. 2-8
Random Access Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Read Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Write Mode ....................................................................... 2-9
Data Retention Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Calipration Buff er Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
MPV ................................................................................. 2-10
Oscillator ........................................................................ 2-11
Housekeeper
IC ....................................................................... 2-11
Digital-to-Analog Converter
............................................................. 2-13
Address Buffer Latch
.................................................................. 2-13
Output Latches ....................................................................... 2.=14
U1005 ................................................................................ 2-14
Reset Circuit ................. , .......................... · .............................. 2-14
l 1A52 Extended Service Manual i

Contents
Analog Control/Signal Amplifiers
............................................................. 2-14
Sample/Hold Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14 '
Coarse and Fine Offsets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15
High Frequency Adjust Signals . . . . . .
.. . . . . . . .. . . .. . . . . .. . . . .. . . .. . . .. . . . .. . . .. . . .. . . .. . . 2-15
Signal Amplifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16
Power Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17
Section 3-Maintenance
Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Amplifier Shield Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Exterior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Interior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2
Visual Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Semiconductor Checks .................................................................. 3-2
Periodic Electrical Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Corrective Maintenance
...................................................................... 3-3
Ordering Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Static-Sensitive Device Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Replacing Parts
........................................................................ 3-5
How to Replace Semiconductors ..................................................... 3-5
How to Remove the Housekeeper Integrated Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
How to Install
the Housekeeper Integrated Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
How to Replace Amplifier Hybrid Circuits
.. . . . . .. . . .. . .. . . .. . . . . . . . .. .. . . . . . . . .. . .. . . . 3-6
How to Replace Peltola Coaxial-Cable Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
How to Remove the Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11 '
v", How to Install the Front Panel o ••••••••••••• ., ................................................ 3-11
How to Replace a Front Panel Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
How to Remove
the Main Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
How to Install the Main Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
How to Remove and Replace a BNC Connector Assembly (BCA)
........................ 3-14
How to Remove
an Attenuator Assembly (AA) ......................................... 3-14
How to Install
an Attenuator Assembly (AA) .......................................... 3-14
Soldering Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
Troubleshooting Aids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
Circuit Board Illustrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
Component Color Coding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
Wiring Color Code
................................................................ 3-18
Semiconductor Lead Configurations
................. ·. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18
Multi-Pin Connector Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20
Troubleshooting Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21
Troubleshooting Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
Check Control Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
Check Associated Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
Visual Check . . . . . . . .
.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
Isolate Trouble to Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
Check Oscilloscope Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23
Check Individual Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23
Repair and Adjust
the Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24
ii 11A52 Extended Service Manual

(
!'
I
Contents
Section 4-Diagnostics
Diagnostics Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Kernel Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
SelfTests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Extended Diagnostics
................................................................... 4-5
Test Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Attenuator-Driver Test (RELAY DRVR)
.................................................. 4-6
Check Probecode Stability (PROBECODES) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4- 7
Check Signal Path Calconstant Checksum (CKSM PLUG)
.................................... 4-7
Check Probe Calconstant Checksum (CKSM PROBE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
Walking Ones Test (WALK ONES)
....................................................... 4-8
Analog-to~Digital Converter Test (ADC TEST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Fuse Test (FUSE TEST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Analog Control Voltage System Test (ACVS TEST)
......................................... 4-9
Calconstant Diagnostics
................................................................ 4-11
PROBE GAIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
ATTEN GAIN . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13
STEP GAIN
..................................................................... 4-13
BWLMATCH ................................................................... 4-13
GAIN
........................................................................... 4-13
OUTPUTERR ................................................................... 4-14
BALANCE
...................................................................... 4-14
COARSE DAC
.................................................................. 4-14
FINE DAC
...................................................................... 4-15
SPARE GAIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
PRB COARSE
................................................................... 4-15
PRB FINE
....................................................................... 4-15
PRB IMBAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
BIAS COMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
BIAS
ERROR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
Explain Cal (EXPLAINCAL)
............................................................. 4-17
ATTEN GAIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
STEP GAIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
BWL MATCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
GAIN
............................................................................ 4-19
Calconstant Dumper (CC DUMPER)
.. ." .................................................. 4-19
·GainOff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
GainOn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
Unreported Amplifier Calibration Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
Trigger Path Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21
Large Amplifier Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21
Old Calibration Constants
.............................................................. 4-21
Failures Reported Though Calibration Achieved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21
CKSM Plug Failure
at Power-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22
11A52 Extended Service Manual
iii

Contents
Section 5 - Replaceable Electrical Parts
Section 6 - Schematic Diagrams and Circuit Board Illustrations
Section 7 - Replaceable Mechanical
Parts
Change Information
Related Documentation
The Replaceable Parts Section at the rear of this manual lists the Tektronix part
numbers for all Standard and Optional Accessories provided with this product.
iv 11A52 Extended Service Manual

( List
of Illustrations
Figure 1-1
Figure 2-1
Figure 3-1
Figure
3-2
Figure 3-3
Figure
3-4
Figure 3-5
Figure 3-6
Figure 3-7
Figure 3-8
Figure
3-9
Figure 4-1
Figure 4-2
Installing
an Amplifier in an Oscilloscope ............................................ 1-2
11A52 Basic Block Diagram
........................................................ 2-3
Exploded View of Housekeeper IC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
Details of Hypcon Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
Peltola Coaxial Cable Connector Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
Nut blocks and Heat Sink Retaining Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
How
the Main Board fits in the Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
Recommended Desoldering Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
Resistor Color Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18
Semiconductor Lead Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19
Multi-Pin Connector Orientation
.................................................. 3-20
Sample LED Fault Code Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Diagnostic Test Results
........................................................... 4-11
11A52 Extended Service Manual v

List of Tables
Table 2-1
Table
2-2
Table 2.:...3
Table 2-4
Table 2-5
Table 2-6
Table
2-7
Table 3-1
Table 4-1
Table
4-2
Table 4-3
vi
The AID Converter Signal Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
Port Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
Miscellaneous Pins ............................................................... 2-11
U600 Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
DAC Latch Control Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
Bandwidth Limit
vs. BPO and BPI Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16
Gain Set by
GPO, GPl, and GP2 Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16
Relative Susceptibility to Damage from Static Discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
11A52 Diagnostic Routines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Bits to Sample-and-Hold Farm Pin Numbers
........................................ 4-10
Meanings of k, Z and j, Y characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
11A52 Extended Service Manual
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Safety Summary
Terms
In This Manual
As Marked on
Equipment
Symbols
In This Manual
As Marked on
Equipment
The general safety information in this part of the summary is for both operating
and servicing personnel. Specific warnings and cautions will
be found throughout
the manual where they apply, but may not appear in this summary.
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.
CAUTION indicates personal injury hazard not immediately accessible as one
reads
the marking, or a hazard to property including the equipment itself.
DANGER indicates a personal injury hazard immediately accessible as one reads
the marking.
@ Static-Sensitive Devices.
This symbol indicates where applicable cautionary or other information
is
to be found.
DANGER-High Voltage.
@ Protective ground (earth) terminal.
& ATTENTION-refer to manual.
11A52 Extended Service Manual vii

Safety Summary
Warnings
Power Source
Grounding
the Product
Danger Arising from
Loss
of Ground
Do Not Operate
in Explosive
Atmospheres
Do Not Service Alone
· Use Care When
Servicing
with
Power On
viii
This product is intended to operate in an oscilloscope connected to a power source
that will not apply more than 250 V rms between the supply conductors or between
either supply conductor and ground. A protective ground connection, by way of the
grounding conductor in the oscilloscope power cord, is essential for safe operation.
This product is grounded through the grounding conductor of the oscilloscope
power cord.
To avoid electric shock, plug the oscilloscope power cord into a prop-
erly wired receptacle before connecting
to the product input or output terminals.
A protective-ground connection, by way of
the grounding conductor in the oscillo-
scope power cord, is essential for safe operation.
Upon loss of the protective-ground connection, all accessible conductive parts (in-
cluding knobs and controls that may appear
to. be insulating), can render an electric
shock.
To avoid explosion, do not operate this product in an atmosphere of explosive gas-
ses.
Do not perform internal service or adjustment of this product unless another per-
son capable of rendering first aid and resuscitation is present.
Dangerous voltages exist
at several points in this product. To avoid personal injury,
do not touch exposed connections and components while power is on.
Disconnect power before removing protective panels, or replacing components.
11A52 Extended Service Manual
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General
Information
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Section
General
1
Information
This section gives all the information needed to apply power to the 11A52 Two Channel Amplifier.
Information
on installing and removing the amplifier, instrument options, packagingfor shipment, and ambient
temperature requirements is
included here.
Introduction
The 11A52 is a two-channel, wide-bandwidth amplifier that plugs into any compatible 1100-series Tektronix
oscilloscope.. All 11A52 functions are controlled by commands from the oscilloscope. The 11A52 front panel has
a momentary pushbutton and a back-lighted "display on" indicator for each input channel; these front-panel
buttons are functional extensionsof the host oscilloscope. The ID
button of any probe so equipped becomes an
11A52 control when that probe is connected to an 11A52 input connector. The oscilloscope candistinguish
between signals from
the 11A52 buttons and probeID buttons. All other controls and status indicators are
located
on the oscilloscope. Refer to the Tektronix Product catalog for complete compatibility information.
Input impedance of each channel is 50 .0.. Each channel's bandwidth can be limited to 20 MHz or 100 MHz.
Each channel provides a
display and a trigger output to the host oscilloscope. Each of those outputs may be
comprised of any oscilloscope-specified combination.of the two input signals. The 11A52 also provides an
auxiliary output from each channel to the oscilloscope. Display and trigger signals can be independently
inverted and summed.
Each channel
has a TEKPROBE™ input connector, which accepts Level 1 and Level 2 TEKPROBE™, any other
probe
with a BNC connector, or any BNC connector. The 11A52 will detect probe-encodinginformation and
automatically account for it to achieve the desired settings.
Amplifier-to-Oscilloscope Compatibility
The 11A52 is designed for use in compatible 11000-series Tektronix oscilloscopes.. 11A52 bandwidth varies
depending on host oscilloscope. Details about bandwidth are included in Part 4, Specification, of the User's
Reference Supplement, and in the Tektronix Product catalog. Refer to the Tektronix Product catalog for
complete compatibility information.
~nitial Inspection
This amplifier was inspected mechanically and electrically before shipment. Inspect the 11A52 for physical
damage that may have occurred during transit. You can verify the instrument performance by performing the
Checks
and Adjustment procedure given in Section 2 ofthe 11A52 Service Reference Manual. If you find damage
or deficiency, contact your local Tektronix field office or representative.
11A52 Extended Service
Manual
1-1

General Information
Installing and Removing the 11A5~ Amplifier
CAUTION
To avoid instrument damage set the oscilloscope ON/STANDBY switch to STANDBY before
installing or removing the 11A52.
If the green indicator light remains ON when the STANDBY position is selected, the switch has
been internally disabled. ·
To remove or reinstall amplifier units, use the Principal Power Switch (rear panel) to shut OFF the
power. This will prevent damage to either the amplifier or the oscilloscope.
To once again enable the ON/STANDBY switch, refer to the Maintenance section of the oscilloscope
service manual.
To install the 11A52 in any compatible 1100-series oscilloscope mainframe, set the oscilloscope ON/STANDBY
switch to STANDBY (see CAUTION above). Align the grooves in the top and bottom of the 11A52 with the
guides
in the oscilloscope amplifier compartment; then insert the 11A52 into the oscilloscope until its front
panel is flush
with the front panel of the oscilloscope.
To remove the 11A52 from an oscilloscope, set the oscilloscope ON/STANDBY switch to STANDBY (see
CAUTION above). Then pull the release latch (see Fig. 1-1) to disengage the unit from the oscilloscope, and
pull the 11A52 straight out of the amplifier compartment.
TOP GROOVE MAINFRAME
7391-101
Figure 1-1. Installing an Amplifier Unit in an Oscilloscope.
1-2 11A52 Extended Service Manual
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General Information
Oscilloscope Options
Option 25 includes two P6231 probes.
Packaging for Shipment
If this amplifier is to be shipped by commercial transportation, we recommend that it be packaged in the
original manner. The original carton and packaging material can be saved and reused for this purpose.
NOTE
Package and ship amplifier and oscilloscopes separately.
If the 11A52 is to be shipped to a Tektronix Service Center for service or repair, attach a tag to the amplifier.
On the tag, include the following information:
• Name and address of the instrument owner
• Name of a person at your firm who canbe contacted aboutthe instrument
• Complete instrument type and serial number and
• A description of the service required.
If the original package is not available or is not fit for use, package the 11A52 as follows:
1. Obtain a corrugated cardboard carton with inside dimensions at least six inches greater than the
amplifier's dimensions. Use a carton with a test strength of
at least 200 pounds.
2. Fully wrap the 11A52 with anti-static sheeting, or its equivalent, to protect the finish.
3. Cushion the 11A52 on all sides by tightly packing dunnage or urethrane foam between the carton and the
amplifier. Allow three inches of packing
on each side.
4. Seal the carton with shipping tape or with industrial staples.
5. Mark the address ofthe Tektronix Service Center and your return address on the carton in one or more
prominent places.
Operating Temperature
The 11A52 can beoperated in ambient temperatures between 0° and +50°C and can be stored in ambient
temperatures
between -40° to +75°C. After storage at temperatures outside the operating limits, allow the
chassis to reach
operating temperature limits before applying power.
l 1A52 Extended Service Manual
1-3

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Theory

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