Tektronix 7B53N User manual

TABLE OF
CONTENTS
Introduction
Simplified Block Diagram
Discussion
Main Sweep Mode
Delayed Sweep Mode
Mixed Sweep Mode
3-1
3-1
3-1
3-3
7B53N
Abbreviations and symbols used in this
manual are based on or
taken directly from IEEE
Standard 260 "Standard Symbols for
Units", MIL STD-12B,
and other standards of the
electronics
industry .
SECTION 1 SPECIFICATION
Page
SECTION 3 CIRCUIT DESCRIPTION
(cont)
Page
Introduction
1-1
Circuit Operation
3-3
Table 1-1
Electrical 1-1
General
Main Trigger
Preamp
3-3
3-4
Main
Sweep Triggering 1-1
Main Trigger
Generator 3-5
Delayed
Sweep Triggering 1-3
Main
Sweep Generator 3-8
Main Sweep Generator
1-4
Delayed Trigger Preamp
3-11
Delayed Sweep Generator
1-4
Delayed Trigger
Generator 3-12
Mixed Sweep, Variable
Time Delay 1-5
Delayed Sweep
Generator 3-13
Amplifier
Output
Signals 1-5 1-6
Horizontal Preamp
3-16
Table 1-2
Environmental Characteristics 1-7
SECTION 4
MAINTENANCE
Table
1-3 Physical 1-7
Introduction 4-1
SECTION 2
OPERATING INSTRUCTIONS
Preventive Maintenance
4-1
Troubleshooting 4-2
General
2-1
Corrective
Maintenance 4-6
Installation 2-1
Controls and Connectors
2-2
SECTION 5
CALIBRATION
General
2-2
Main
Triggering Controls
2-2
Introduction
5-1
Sweep
Controls
2-4
Tektronix Field
Service 5-1
Delayed Trigger Controls
2-4
Using This
Procedure 5-1
Front-Panel Connectors
2-5
Test
Equipment Required
5-1
Sweep Calibration
2-6
Preliminary Control Settings
5-2
Simplified
Operating Instructions 2-6
Part 1 Performance Check
5-4
Main
Sweep
2-6
Index to Part I-Performance
Check 5-4
Magnified Display
2-6
Preliminary
Procedure for
Delayed Sweep Display
2-6
Performance Check
5-4
Mixed Sweep Display
2-7 Trigger
System Check
5-5
General
Operating Instructions 2-7
Horizontal System Check
5-11
Pushbutton Switch
Logic
2-7
Output Signals Check
5-17
Triggered Light
2-7
Part 11 Adjustment
5-18
Main Trigger Mode
2-7
Index to Part
11-Adjustment 5-18
Main Trigger Coupling 2-8
Preliminary Adjustment
Procedure 5-18
Main Trigger Source
2-9
Trigger System Adjustment 5-19
Main Trigger Slope
2-10
Horizontal System Adjustment
5-25
Main Trigger
Level
2-10
Output Signals
5-29
Selecting
Sweep Rates
2-10
Time Measurement
2-10
SECTION 6 ELECTRICAL
PARTS LIST
Sweep Magnifier
2-12 Abbreviation
and Symbols
Main Sweep Operation
2-12
Parts
Ordering Information
Delayed Sweep
Operation 2-12
Index to Electrical Parts List
MixedSweep
Operation
2-13
Electrical Parts List
Delayed
Sweep Triggering
2-13
Delayed Gate Output
2-14
SECTION 7 DIAGRAMS AND
CIRCUIT BOARD
Applications
2-14
ILLUSTRATIONS
General
2-14
Comparison
Measurement Symbols
and Reference Designators 7-1
Techniques 2-14 Diagrams
Time Duration Measurements
2-15 Circuit Board Illustrations
Determining Frequency
2-16
Risetime
Measurements
2-16 SECTION 8
MECHANICAL PARTS LIST
Delayed Sweep
Measurements 2-17
Mechanical Parts List Information
Delayed Sweep
Magnification 2-18
Index of Mechanical Parts List
Triggered
Delayed Sweep
and Illustrations
Magnification
2-19
Mechanical
Parts List
Pulse Jitter Measurements
2-19
Accessories
SECTION 3 CIRCUIT DESCRIPTION

Introduction
The 7B53N
is a dual time base unit designed for use in
Tektronix 7000-Series Oscilloscopes without a readout
system
; however it is compatible with all 7000-Series
Oscilloscopes
. The 7B53N features calibrated sweeps from
5 seconds/division to 50 nanoseconds/division (5
nanoseconds/division
with X10 magnification) . The Main or
Delayed sweep rates may be varied continuously (uncali-
brated) between calibrated steps . Sweep triggering is pro-
vided to at least 100
megahertz, Separate trigger
controls
are provided
to select the desired triggering
for the main
and
delayed sweeps .
O
SECTION l
SPECIFICATION
TABLE 1-1
ELECTRICAL
MAIN SWEEP TRIGGERING
7B53N
Four display modes are provided . These include separate
display of the main sweep, an
intensified display, delayed
sweep, and mixed sweep
. The 7B53N can also be used as an
amplifier for X-Y
operation .
This instrument will meet the electrical characteristics
listed under Performance Requirement
in Table 1-1, fol-
lowing complete calibration
. The following electrical char-
acteristics apply over an ambient temperature range of 0 ° C
to +50 ° C, except as otherwise indicated . Warmup time for
given accuracy is 20 minutes .
Characteristic Performance Requirement Supplemental Information
Source
Internal from associated vertical unit . Selected by SOURCE switch .
Internal from AC power source .
External
External divide by ten .
Coupling AC Selected by COUPLING switch .
AC
low-frequency reject .
AC high-frequency reject .
DC
Polarity Sweep can be triggered from positive- Selected by LEVEL/SLOPE control .
going
or negative-going portion of trigger
signal .
Internal Trigger Sensitivity
AC 0 .3 division of deflection, minimum, 30 The specified upper -3 dB frequency
hertz to 10 megahertz ; increasing to 1 .5
of
the vertical system supersedes
the
divisions at
100
megahertz .
frequency limits given in the Internal
Trigger Sensitivity table when the
number in the table is greater
than the
upper -3 dB frequency of the vertical
unit .

Specification-7B53N
Performance
Requirement
0 .3
division of deflection, minimum,
30
kilohertz
to 10 megahertz ; increasing
to
1 .5
divisions at 100 megahertz
.
0 .3 division of
deflection, minimum, 30
hertz to 50
kilohertz .
0 .3 division
of deflection, minimum, DC
to 10
megahertz ; increasing to 1 .5
divi-
sion
at 100 megahertz .
100 millivolts, minimum, 30
hertz
to 10
megahertz
; increasing to 500
millivolts at
100 megahertz .
100
millivolts, minimum, 150 kilohertz
to 10 megahertz ; increasing to 500 milli-
volts at 100 megahertz .
100
millivolts, minimum, 30 hertz to 50
kilohertz .
100 millivolts, minimum, DC to 10
mega-
hertz ; increasing to 500 millivolts at
100
megahertz .
Stable display presented with signal
amplitudes given
under Internal and Ex-
ternal
Trigger Sensitivity above 30 hertz .
Presents
a
free-running sweep for lower
frequencies or in absence of a trigger
signal .
Main Sweep Generator produces only one
sweep when triggered . Further
sweeps are
locked out
until RESET button is
pressed . Trigger sensitivity same as given
for internal and external sensitivity .
1 nanosecond or less at
75 megahertz .
AC LF REJ
AC
HF REJ
DC
External Trigger Sensitivity
AC
AC
LF REJ
AC HF
REJ
DC
Auto Triggering
Single Sweep
Characteristic
Internal Trigger
Jitter
External Trigger Input
Input R and C
Maximum
Safe Input Voltage
TABLE 1-1 (cont)
Supplemental
Information
SOURCE switch set to EXT .
Trig-
gering signal requirements
increased 10
times for EXT=10 position
.
Approximately 1 megohm paralleled
by 20 pF .
500 volts (DC +
Peak AC)
.
500 volts
peak-to-peak AC at 1 kilohertz or less .

Level Range
EXT
TABLE 1-1 (cont)
Characteristic

I

Performance
Requirement
EXT
-
10
At least
+and
-1 .5 volts .
At least + and
-15 volts .
DELAYED SWEEP TRIGGERING
Specification-71353N
Supplemental
Information
Source
Internal from associated
vertical unit Selected by Delayed
Triggering
SOURCE switch .
External
Coupling
AC
Selected by Delayed Triggering
COUPLING switch .
DC
Polarity
Sweep can be triggered from positive- Selected by
Delayed Triggering SLOPE
going or negative-going portion of trigger
switch .
signal .
Internal Trigger Sensitivity
AC
0 .3 division of deflection,
minimum, 30
hertz to 10 megahertz
; increasing to 1 .5
divisions at 100 megahertz .
DC
0 .3 division of deflection, minimum,
DC
to 10 megahertz, increasing
to 1 .5 divi-
sions at 100
megahertz .
External Trigger Sensitivity
AC
100 millivolts, minimum, 30 hertz to 10 Delayed Triggering SOURCE switch
megahertz ; increasing to 500 millivolts at
set to EXT .
100 megahertz .
DC
100 millivolts, minimum, DC to
10 mega-
hertz ; increasing to
500 millivolts at 100
megahertz
.
Internal
Trigger
Jitter 1 nanosecond or less at 75 megahertz
.
External Trigger Input
Maximum
Safe Input Voltage
500 volts (DC + Peak AC) . 500 volts
peak-to-peak AC at 1 kilohertz or
less .
Input R and C
1 megohm paralleled by 20 picofarads .
Level Range
At least
+and
-1 .5 volts .

Specification-71353N
TABLE 1-1 (cont)
MAIN SWEEP
GENERATOR
DELAYED
SWEEP GENERATOR
Characteristic
Performance Requirement Supplemental Information
Sweep Accuracy
Measured in 7400- and 7500-Series
Oscilloscopes
Time Interval
+15 ° C to
+35
° C 0° C to +50 ° C
Over Center 8
Divisions Unmagnified Magnified Unmagnified
Magnified
50 milliseconds/division to
Within 2%
Within 2 .5% Within 3% Within 4%
0 .5 microsecond/division
5 seconds/division to
0 .1
second/division and 0 .2
Within 3%
Within
3.5%
Within 4% Within 5%
microsecond/division to
0 .05 microsecond/division
Sweep Linearity
Over
any 2 division portion with-
in center
eight divisions (all Within 5%
Within 7%
sweep rates)
VARIABLE Sweep Rate
Range Continuously variable between calibrated Extends
sweep rate to at least 12 .5
sweep rates .
seconds/division . VARIABLE control
internally switchable between Main
and Delayed Sweeps .
Sweep Hold-Off
Time
5 seconds/division
to 10 micro- 1 .5 times the TIM E/D IV setting or less
seconds/division
5 microseconds/division
to 0 .5 2 .5 microseconds or less
microsecond/division
Normal-Mag Registration Within 0 .5 division
Sweep Accuracy
Time Interval
Measured in
Oscilloscopes .
+15 ° C
7400-Series or
to +35 ° C
7500-Series
0 0 C
to
50 °
C
Over Center 8 Divisions
Unmagnified Magnified Unmagnified Magnified
50 milliseconds/division to
Within 3% Within 3.5% Within 4% Within 5%
0 .5 microsecond/division
0 .5 second/division to 0 .1
second/division and 0 .2
Within 4% Within
4
.5% Within 5%
Within
6%
microsecond/division to
0 .5 microsecond/division

Within 2% ± measured Main Sweep
error
Within
2%
Within 1%
Within 0 .2% of full scale (1 minor divi-
sion)
Less than 1 part in 20,000 of the maxi-
mum available
delay
time (10 times
the
Main
Sweep TIME/DIV switch setting) .
Sweep Accuracy
DELAY TIME MULT
Delay Accuracy over
center
eight
divisions
5 seconds/division to 1
second/division
0 .5
second/division to 1
microsecond/division
Multiplier Linearity
Delay Time Jitter
TABLE 1-1 (cont)
MIXED SWEEP, VARIABLE TIME
DELAY
AMPLIFIER
Specification-71353N
Exclude the following portions of
Mixed Sweep :
First
0 .5
division after start of MAIN
sweep display and 0 .2 division or 1
microsecond (whichever is greater)
after transition of MAIN to
DLY'D
sweep
10 millivolts/division within 10% .
100 mill
ivolts/division within 10% .
1
volt/division within 10% .
Deflection
Factor
EXT, MAG X10
EXT, MAG off
EXT= 10, MAG
off
Characteristic
Performance Requirement Supplemental Information
Sweep Linearity
Over any 2 division portion with-
in center eight divisions (all
Within 6%
Within 8%
sweep rates)
VARIABLE
Sweep Rate Range Continuously
variable between calibrated Extends sweep rate to at least
1 .25
sweep rates .
seconds/division . VARIABLE control
internally switchable between Main
and Delayed Sweeps .
Sweep Hold-Off Time
Determined
by the Main Sweep TIME/
DIV setting .

Specification-71353N
Performance Requirement Characteristic
TABLE 1-1 (cont) .
OUTPUT SIGNALS
Supplemental
Information
Delayed Sweep Gate
Available at front-panel DLY'D TRIG
IN connector
when operating in a
Waveshape
Rectangular pulse
delayed sweep mode with the Delayed
Triggering SOURCE switch set to INT .
Amplitude +3 .5 volts within 40°% with baseline at 0
to -1 volt .
Polarity
Positive-going
Duration For the time of the
delayed
sweep
Output
Resistance Approximately 1 kilohm
Loading
At
least
10
kilohms shunted by 100
picofarads or less .
Composite Sweep Gate Coupled to associated indicator
oscilloscope
by way of
pin
A1
on
In-
Waveshape Rectangular pulse .
terface
circuit
board .
Polarity
Positive-going
Duration
DISPLAY MODE
MAIN
SWP
Coincident with the main sweep interval .
INTEN Coincident with the main sweep interval
.
DLY'D
SWP Coincident with the delayed sweep in-
terval .
MIXED Coincident with the main sweep interval
plus the delayed sweep interval
.
Nominal
Frequency Response
System -3 dB points in 7400-Series or
7500-Series Oscilloscope .
AC
Lower -3 dB
40 hertz
Upper -3 dB
2 megahertz
AC LF REJ 16 kilohertz 2megahertz
AC HF REJ
40 hertz 100 kilohertz
DC DC
2 megahertz