Tektronix 7623 User manual

STORAGE
SCILLOSCOPE
SERVICE

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SECTION 2

CALIBRATION
CONTENTS
SECTION 1

OPERATING INFORMATION

Page
Operating Voltage

1-1
Operating Temperature

1-1
Plug-In Installation And Removal

1-1
Operation

1-1
Non-Store Operating Set-Up Information

1-1
Front Panel Controls And Connectors

1-2
Rear Panel Controls And Connectors

1-3
Storage Modes

1-4
Variable Persistence Operating Set-Up Information

1-4
Fast Operating Set-Up Information

1-4
Multi-Trace Fast Operating Set-Up Information

1-4
Bi-Stable Operating Set-Up Information

1-4
Save Mode Operating Set-Up Information

1-4
Calibration Interval

2-1
Tektronix Field Service

2-1
Using This Procedure

2-1
General

2-1
Index

2-1
Performance

2-1
Partial Procedure

2-1
Complete Calibration Procedure

2-1
TEST EQUIPMENT REQUIRED
Special Calibration Fixtures

2-1
Calibration Equipment Alternatives

2-1
Test Equipment

2-2
Preliminary Control Settings

2-4
CALIBRATION PROCEDURE

2-5
Introduction -

2-5
Index To Calibration Procedure

2-5
Power Supply

2-5
Display And Z-Axis

2-5
Vertical Deflection System

2-5
Trigger System

2-5
Horizontal Deflection System

2-5
Z-Axis And Auto Focus

2-5
Calibrator

2-5
Signals Out

2-5
Readout Operation

2-6
Storage Operation

2-6
7623/R7623
Service

7623/R7623 Service
OF
CONTENTS (cont)
SECTION 3 CIRCUIT
DESCRIPTION
Page
Block
Diagram
3-1
Circuit Operation
3-1
Logic Fundamentals
' 3-3
Symbols
3-3
Logic Polarity
3-3
Input/Output Tables
3-6
Non-Digital Devices
3-6
MAIN
INTERFACE
3-6
LOGIC
CIRCUIT
3-6
Logic Block
Diagram
3-6
Z-Axis Logic
3-6
Clock Generator
3-9
Vertical Chopped Blanking
3-10
Chop Counter
3-11
Vertical Mode Control
3-13
Right
3-13
Chop
3-13
Alt 3-14
Add
3-14
Left
3-14
Vertical Binary
3-14
Plug-In Binary
3-15
Output Buffers
3-16
TRIGGER SELECTOR
3-16
Trigger Mode And Add Signals
3-16
General
3-16
Vert Mode
3-16
Left
3-16
Right
3-18
Trigger Channel Switch
3-18
Trigger Output Amplifier
3-18
Vertical Signal Buffer
3-18
VERTICAL INTERFACE
3-19
Vertical Channel Switch 3-19
Auxiliary Y-Axis Input Amplifier
3-20
Delay
Line Buffer
3-20
Delay
Line
3-20
VERTICAL
AMPLIFIER
3-20
Input Balance
3-21
Output Amplifier
3-21
Beam Finder Network
3-21
HORIZONTAL
AMPLIFIER
3-21
Horizontal
Channel Switch
3-21
Right Output Amplifier
3-22
Left Output Amplifier
3-22

TA
O
CONTENTS
(cont)
SECTION 3

CIRCUIT DESCRIPTION (cont)

Page
7623/137623 Service
CALIBRATOR And FRONT PANEL SWITCHING 3-22
Mode Switch Logic 3-23
Calibrator 3-23
Oscillator 3-23
Output Amplifier 3-23
Output Divider
3-23
CRT CIRCUIT
3-24
Z-Axis Amplifier 3-24
Auto Focus Amplifier 3-25
High
Voltage Oscillator 3-25
High
Voltage Regulator 3-25
High
Voltage Supplies 3-26
CRT Control Circuits 3-26
LOW-VOLTAGE POWER SUPPLY 3-27
Power Input 3-27
-50 Volt Supply 3-27
-15 Volt Supply 3-30
+5 Volt Supply 3-30
+15 Volt Supply 3-30
+50 Volt Supply 3-30
+130 Volt Supply 3-31
Graticule Light Supply 3-31
SIGNAL OUT BOARD 3-31
Vert
Sig Out 3-31
+Gate Out 3-31
+Sawtooth Out 3-31
READOUT SYSTEM 3-31
Display Format 3-32
Developing The Display 3-32
Circuit Analysis Of The Readout System 3-35
Timer 3-35
Time-Slot
Counter
3-40
Word Trigger 3-40
Channel
Counter 3-41
Single-Shot Lockout 3-41
Encoding The Data 3-41
Column And Row Data Switches 3-43
Display-Skip Generator 3-44
Column And Row Decoder 3-44
Zeros Logic
And Memory 3-44
Character Generators 3-47
Decimal
Point Logic And Character Position Counter 3-47
Format Generator 3-48
Y-Output Amplifier 3-48
X-Output Amplifier 3-48
Display Sequence 3-48

7623/137623
Service
TABLE
®F CONTENTS (confi)
SECTION 3

CIRCUIT
DESCRIPTION (cont)

Page
SECTION 4 MAINTENANCE
Panel Removal
4-1
Cabinet Model
4-1
Rack Model
4-1
Power-Unit
Removal
4-1
PREVENTIVE MAINTENANCE
4-1
General
4-1
Cleaning
4-1
Exterior
4-2
CRT 4-2
Interior 4-2
Lubrication 4-2
Semiconductor Checks
4-2
Recalibration 4-2
TROUBLESHOOTING 4-2
Introduction
4-2
Diagrams
4-3
Circuit Boards
4-3
Multi-Pin Connector Color-Code
4-3
Wiring Color-Code
4-3
Resistor Color-Code
4-3
Capacitor Marking
4-3
Diode Color-Code
4-3
Semiconductor Lead Configuration
4-3
Troubleshooting Equipment
4-3
Troubleshooting Techniques
4-6
STORAGE CIRCUITRY
3-50
Erase And Timing Circuits
3-50
Sweep Lockout Circuit
3-50
Auto Erase Circuit
3-50
Readout Shut Down Circuit 3-54
Persistence Pulse And Pump Pulse
Generator Circuits
3-54
Flood Gun Anode And CE2 Circuits
3-55
CES And CE2 Circuits 3-55
Collector Circuit
3-56
High Speed Mesh Circuit 3-56
Bi-Stable Mesh Circuit
3-56

CHANGE INFORMATION
OF CONTENTS (cont)
SECTION 4

MAINTENANCE (cont)

Page
7623/137623 Service
CORRECTIVE MAINTENANCE
4-10
Obtaining Replacement Parts
4-10
Special Parts
4-10
Ordering Parts
4-11
Soldering Techniques
4-11
Component Replacement
4-11
General
4-11
Circuit Board Replacement
4-11
Access To The Fan Motor 4-13
Access To The Fan Motor For The 137623 4-13
Semiconductor Replacement
4-14
Access To The Power Transistors
4-14
Interconnecting Pin Replacement 4-14
Cathode Ray Tube Replacement 4-15
Switch
Replacement 4-16
Graticule Bulb Replacement 4-16
Power 'Transformer Replacement
4-16
High-Voltage
Compartment 4-16
Fuse Replacement 4-16
Recalibration After Repair 4-16
Instrument Repackaging 4-17
SECTION 5 ELECTRICAL PARTS
LIST
SECTION 6 DIAGRAMS
SECTION 7 MECHANICAL PARTS LIST

7623/137623
Service
The TEKTRONIX 7623/137623 Storage Oscilloscope is a solid-state
instrument designed for fast writing rate storage
applications . The 7623 has four basic modes of operation
:
Fast, Bi-Stable, Variable
Persistence,
and
Non-Store . The in-
strument is designed to accept TEKTRONIX 7-Series plug-in units to form a complete measurement system . The
flexibility of this plug-in feature and the variety of plug-in units available allow
this system to be used for many measure-
ment applications . The 7623 features
a large cathode-ray tube (CRT) screen,
8 X 10 divisions, with small spot size, and
fast stored writing rate .
O

Operating Voltage
Operating Temperature
Plug-in Installation
and Removal
OPERATING INFORMATION
The
7623/R7623 can be operated from either a 110-volt
line or 220-volt
line source . In addition, three operating
ranges can be selected by a jumper located on the Rectifier
board
. See Fig . 1-1 . Select a range that is centered about
the average line voltage to which the instrument is
connected . See Table 1-1 for ranges and proper fuses .
Table 1-1
The 7623/R7623 can be operated where the ambient
air
temperature is between 0 ° C and +50 ° C . The 7623 is cooled
by
air drawn through the instrument .
Maintain about
two-inches
clearance for proper ventilation on all sides and
the top .
The feet
on
the bottom of the instrument provide
the necessary clearance
. The R7623 is cooled by air drawn
through the air filter on the rear of the instrument and
blown out through the holes on the right side . Maintain
two-inches of clearance on the right side for proper
ventilation . A thermal cutout switch in the
instruments
provides thermal protection, and interrupts
the power
to
the instrument if the internal temperature
exceeds a safe
operating level .
To install a plug-in unit into
one of the plug-in
compartments, align the slots in
the
top and bottom
of the
plug-in unit with the associated guide
rails in the plug-in
compartment . Push the plug-in unit firmly into
the plug-in
compartment until it locks into
place .
To
remove the
plug-in unit, pull the release
latch
on
the plug-in unit to
disengage it, and pull the unit out of the plug-in
compartment . Plug-in units can be removed or installed
without turning off the instrument power . Special purpose
plug-in units may have specific restrictions regarding the
plug-in
compartments in which they can be installed . This
information will be given
in the instruction manual for
these plug-in units .
Operation
The
following information provides
the necessary
controls and control settings to obtain a display,
which can
be used to verify basic operation or calibration
without
removing the covers or making any
internal adjustments . In
the NON STORE mode the 7623
functions the same as a
conventional oscilloscope . The
CALIBRATOR signal is a
convenient signal for verifying basic operation
and
calibration . Use the Operating
Set-Up Information as a
guide for setting the
front panel controls .
Non-Store Operating Set-Up Information
INTENSITY
READOUT

As desired
GRATICULE ILLUM

As desired
As desired (midrange)
FOCUS

Well defined display
TRIG SOURCE

VERT MODE
VERT MODE

Selected

for the plug-in
compartment with the
plug-in unit installed and
with signal input to be
displayed .
POWER

Pressed in
Section 1-7623/R7623 Service
+15 V Fuse

ALT fuse

Spare jumper
Fig . 1-1 . Location of Voltage-selector jumper, spare jumper, and
230
V fuse in power-unit (shown removed) .
Pins Regulating Range
Selected 110-volt
nominal
220-volt
nominal
Low 90 to 110 volts 180 to 220 volts
Med
99 to 121
volts
198 to
242 volts
Hi I 108 to 132 volts I 218 to 262 volts
Line Fu s e 3 .2
A
Sl o w-bl o w 1 .6
A
Sl o w-blow

Operating
Information-7623/R7623 Service
1 . INTENSITY-Controls the brightness of
the display .
2 . READOUT-Turns
on the Readout dis-
play, and controls the
brightness of the
Readout
display .
3 .
FOCUS-Screwdriver adjustment provides
adjustment for optimum display definition .
4 .
GRATICULE ILLUM-Controls graticule
illumination .
5 . BEAM
FINDER-When
pressed the display
is limited to within the graticule area .
6 . Camera Power-Three pin connector on the
CRT bezel, (top) +15 volt power source,
(middle) receives remote single sweep reset
signal from compatible camera system, and
(bottom) ground pin .
7 . VERT MODE-Selects vertical mode of operations .
LEFT : Signals from the left
plug-in compartment are dis-
played .
ALT : Signals from both vertical
plug-in compartments are
displayed (dual trace)
.
Display is switched from one
vertical
to the other after each sweep .
ADD : Signals from both
vertical plug-in compartments are
algebraically added, and
the sum is displayed .
CHOP : Signals from both vertical compartments
are dis-
played (dual trace)
.
Display switches from the left
vertical
compartment signal to the right vertical compartment
signal
at a one megahertz rate .
RIGHT : Signals
from the right plug-in compartment
are
displayed .
8 . TRIGSOURCE -Selects the source of the internal trigger signals
for the horizontal compartment .
9 . POWER-Switch and indicator ; switch
turns on instrument, and
the indicator is on when the instrument
is connected to a power
source and turned on .
LEFT : Trigger signals are from
the left vertical plug-in
compartment only .
VERT MODE : Trigger signals are from the vertical compart-
ment being displayed except in the CHOP and ADD modes ;
then the trigger signal is the algebraic sum of the trigger
signals from the left and right plug-in compartments .
RIGHT : Trigger signals are from the right vertical plug-in
compartment only .
10 . NON-STORE-Non-store operation .
Fig . 1-2
. Front Panel Controls and Connectors .
11 . VAR-PERSIST-Variable persistence storage mode . The
AUTO
VIEW TIME or PERSISTENCE control setting, controls the
retention of the stored display .
12 . FAST-For storing fast signals .
13 . MULTI-TRACE-(MULTI-FAST in early instruments)-For stor-
ing multiple fast signals . For each new signal to be stored the
ERASE (PREP IN MULTI TRACE FAST) must be pressed .
14
.
INTEG-For storing very fast repetitive signals
.
15 . BI-STABLE-For
storing slow signals for long periods of time .
16 . SAVE-Prevents accidental erasure
of
the stored display .
17 . SAVE INTEN-(STORED INTEN in early instruments) -Controls
the brightness of the stored display in the Save Mode .
18 . AUTO ERASE-Automatically erases the stored display, AUTO
VIEW TIME setting
controls the time
between erase
cycles
.
19 . AUTO VIEW TIME-(VIEW TIME in early instruments)-
Controls the time between erase cycles in the Auto Erase
Mode
.
20 .
MANE RASE-Erases the stored display .
21 . STORAGE LEVEL-(LEVEL in early instruments)-Controls
the writing rate in the FAST and BI-STABLE storage modes .
Controls
the writing
rate and brightness of the stored display
in the Variable persistence Mode .
22 . CALIBRATOR-Positive going square wave or DC voltage
selected by changing an internal jumper . Output voltage at pin
jacks
(4
V, 0 .4 V and 40 mV)
.

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1 . FUSE-Line voltage fuse
.
2 . REMOTE ERASE
IN-Provides external connection for remote
erase .
3 . EXT
S S RESET IN-Remote single sweep reset .
4 . EXT Z
AXIS IN-Input for intensity modulation of the CRT
display .
5 . V E RT SIG OUT-Vertical signal selected by
switch (LEFT, RIGHT, ALT and
ADD) .
6 . +GATE OUT-Gate signal selected by gate
(Main, Auxiliary,
and Delay) .
7 .
+SAWTOOTH OUT-Positive-going sawtooth
unit .
Fig .
1-
3 . Rear Panel Controls and Connectors .
Operating Information-7623/R7623
Service
TRIG
SOURCE
selector switch
from time-base
E

Operating Information--7623/R7623
Service
After obtaining a display in the NON Store mode
continue
to
the
Storage modes .
Storage Modes
Set the controls as given in the Operating Set-Up
Information for the Non-Store mode . Set
the storage
controls as given for Variable Persistence,
Fast,
Bi-Stable
and Save mode .
Variable
Persistence Operating
Set-Up Information
VAR PERSIST

In (Pressed in)
NON STORE

Out (released)
STORAGE LEVEL

As desired (no fading positive
of
the display)
PERSISTENCE

As desired (counterclockwise in the
detent
is maximum
retention ; in
the clockwise direction
the
retention decreases .)
SAVE

Out (released)
.
FAST Operating Set-Up
Information
ERASE

Press ERASE button
FAST

In (pressed in) .
VAR PERSIST

Out
(Released) .
AUTO ERASE

Out . Pressed
and released . (Only
one
sweep is stored . Press the MAN .
ERASE
button to erase the display,
and to start another sweep for
storing .)
STORAGE LEVEL As
desired (adjusted so stored
display does not fade into the
background) .
MULTI TRACE FAST Operating
Set-Up
Information
Obtain one stored display
in the fast mode .
MULTI TRACE

In
ERASE

Pressed and released . (Only one
sweep is stored, press the ERASE
button and another sweep will be
stored
without erasing the original
display .)
SAVE

Out (released) .
Bi-Stable Operating Set-Up Information
BI-STABLE

In (pressed in)
FAST

Out (released)
ERASE

Press
ERASE
button
SAVE Mode Operation Set-Up
Information
Obtain a stored display in any storage mode .
SAVE

In (Pressed in)
SAVE INTEN

Turning the SAVE INTEN control
clockwise increases the intensity of
the stored display . There is no erase
signal generated, and all sweep
signals are locked-out . Press the
SAVE button out (release) .
Auto ERASE

Pressed in
Auto VIEW TIME

As

desired

(counterclockwise
position maximum display time
before erase cycle starts . Clockwise
direction decreases time that a
stored display is present before an
erase cycle)
.
AUTO
ERASE

Pressed and released (out) .
For more detailed operating instructions, see the
7623/R7623 Operators Manual .

Calibration Interval
'To
assure instrument
accuracy, check the calibration
of
the 7623 every 1000 hours
of operation, or
every six
months
if used infrequently . Before complete calibration,
thoroughly
clean
and inspect
this instrument as outlined in
the Maintenance section
.
Tektronix Field Service
Tektronix, Inc . provides complete instrument repair and
recalibration at local Field Service
Centers
and
the
Factory
Service Center . Contact your
local Tektronix Field Office
or representative
for further information .
Using This Procedure
CALI
General . This section provides several features to facili-
tate calibration of
the 7623 . These are :
Index . An index is given preceding the calibration
procedure to aid in locating a step .
Performance Check
. The performance
of
this instrument
can be checked by performing
only the %/CHECK steps
.
The \/ preceding a step indicates that
performing
this step
checks the instrument against the tolerance listed as a
Performance
Requirement (see Specification Section in the
Operators Manual)
.
Partial Procedure .
A partial calibration is often desirable
after replacing components, or to
touch up the adjustment
of a portion of the instrument between major recalibra-
tions . To calibrate only part of the instrument, set the
controls as given under
Preliminary Control Settings and
start
with the nearest Equipment Required list preceding
the desired portion . To prevent unnecessary recalibration of
other parts
of
the instrument, re-adjust only if the tolerance
given in the CHECK-- part of the step is not met . If
re-adjustment is necessary, also check the calibration of any
steps listed in
the INTERACTION-part of the step .
Complete Calibration Procedure . Completion of each
step in the following calibration procedure ensures that this
instrument is both correctly adjusted and performing
within all given tolerances .
Section 2-7623/R7623
Service
TEST EQUIPMENT REQUIRED
The test equipment and accessories, or the equivalent,
given in the Test Equipment table is required for complete
calibration of the 7623 . Specifications given for the test
equipment are the minimum necessary for accurate calibra-
tion
. Therefore, the specifications of any test equipment
used must meet or exceed the listed specifications . All test
equipment is assumed to be correctly calibrated and
operating within the listed specification . Detailed operating
instructions for the test equipment are not given in this
procedure . Refer to the instruction manuals for the test
equipment for more information .
Special
Calibration Fixtures
Special Tektronix calibration fixtures are used in this
procedure only where they facilitate instrument calibration .
These special calibration fixtures are available from
Tektronix, Inc . Order by part number through your local
Tektronix Field Office or
representative .
Calibration Equipment Alternatives
All
of
the listed test equipment is required to completely
check and adjust this instrument . This
calibration
pro-
cedure is based on the first item of equipment given as an
example
of applicable
equipment
.
When other equipment is
substituted,
control settings or calibration setup may need
to be altered slightly to meet the requirements of the
substitute
equipment . If the exact item of test equipment
given as an example in
the Test Equipment table
is
not
available, first
check the Specifications column carefully
to
see
if any other equipment is available which might suffice .
Then check the Usage
column
to
see
what
this item of test
equipment is used
for . If used for
acheck or
adjustment
which is of little or no
importance to your measurement
requirements,
the
item
and corresponding step(s) can
be
deleted .
The following procedure is written to completely check
and adjust the 7623 to the limits given in Section 2 of the
Operators Manual and to allow interchanging 7000-series
plug-in units between 7000-series mainframes without the
need to recalibrate
the instruments each time . If applica-
tions for
which you will use the 7623 do not require the
full available
performance from the 7623 and plug-in units,
this procedure and
the required equipment list can be

Calibration---7623/R7623 Service
shortened accordingly . For example, the basic measurement
capabilities
of
this instrument can
be
verified
by checking
vertical deflection accuracy, vertical square-wave response,
and basic horizontal timing with 7000-series real-time
plug-in units and an accurate square-wave signal . Also, if the
Description
1 . Precision DC Voltmeter
3 . "Time-Mark Generator
4 . Medium frequency con-
stant amplitude signal gen-
erator
5 . Low frequency signal
generator
6 . Test oscilloscope system
(dual-trace)
2-2
Minimum Specifications
Range, zero to 150 Volts ;
accuracy, within 0 .2% .
Range, zero to 4000 Volts ;
accuracy, checked to with-
in 1% at 1500 Volts .
Marker outputs, 10 nano-
seconds to 0 .1 second ;
marker accuracy, within
0 .1% ; Trigger output, one
millisecond .
Frequency,
50 to 100
megahertz ; reference fre-
quency, 50 kilohertz ;
out-
put amplitude, variable
from 5 millivolts to 5
Volts peak-to-peak into 50
ohms ; amplitude accuracy,
constant within 3% of ref-
erence as output fre-
quency
changes .
Frequency, 35 kilohertz ;
output amplitude, variable
from
50 to 100 millivolts .
Bandwidth,
DC to 50
megahertz ; minimum
de-
flection
factor, 10
millivolts/div ;
accuracy,
within
3% .
TEST EQUIPMENT
7623 is to be used in a fixed system without the need to
interchange plug-in units,
all
tests can be made by substi-
tuting
vertical
plug-in units
and applicable test
signals for
the 067-0587-01 mainframe standardizer calibration fix-
ture .
Usage
Calibrator output accuracy
check and adjustment .
High
voltage power supply
check . Z-Axis
DC levels
adjustment .
CRT geometry
check and
adjustment
.
Horizontal
timing check and
adjust-
ment .
External Z-axis operation
check . Horizontal and Ver-
tical bandwidth check .
Vertical amplifier
isolation
check and storage writing
rate .
X-Y phase shift check and
storage writing rate .
Horizontal limit centering
adjustment and
+
GATE
OUT .
Examples of Applicable
Test Equipment
a . Tektronix 7D13 Digital
Multi-
meter
(test oscilloscope must have
Readout System) .
b . Fluke Model 825A Differential
DC Voltmeter .
.
Triplett Model 630-NA .
b . Simpson Model 262 .
a . Tektronix 2901 Time-Mark Gen-
erator .
b . Tektronix 184 Time-Mark Gen-
erator
.
a . Tektronix 191 Constant Ampli-
tude
Signal Generator .
b . General Radio 1215-C with
1263-C Amplitude Regulating
Power
Supply
.
a . General Radio
1310-B Oscillator
with a binding post
to
BNC
adapter
(274-QBJ General
Radio) .
a . Tektronix 7503 or 7504 oscillo-
scope with two 7A15A or 7A16
Amplifier and 7B50 and 7B53A
Time Base plug-in units
P6053 Probes .
and two
b . "Tektronix 453A oscilloscope
with two P6054
Probes .

Compatible with 713-series
external trigger input .
Description
7 . Vertical plug-in unit
(two identical units re-
quired), and a dual display
vertical unit .
8 . Time-base plug-in unit
9 . Mainframe standardizer
calibration fixture
10 . 10X passive probe
11 . T connector
12 .
Termination
13 . Dual-input coupler
14
.
Cable (two required)
15 .
GR in-line termination
16 . Cable
Tektronix
7A-series 65
megahertz
bandwidth
re-
quired for complete pro-
cedure as written .
Tektronix 713-series .
Impedance,
50-ohms ;
accuracy, ±2% ;
tors, BNC .
Connectors, BNC .
connec-
TEST
EQUIPMENT
(cont)
Usage
Used throughout pro-
cedure
to provide vertical
input
to
the instrument
under calibration . Identi-
cal units required for only
X-Y phase shift check .
Used through procedure
to
provide sweep .
Used throughout pro-
cedure
to standardize in-
strument
so plug-in units
can
be interchanged with-
out complete recalibra-
tion
.
Chopped mode operation
check
(adjustment pro-
cedure)
.
External Z-axis operation
check .
Horizontal timing check
and
adjustment . X-Y phase
shift check .
Added operation check .
X-Y phase shift check .
Calibration--7623/R7623 Service
Examples of Applicable
Test Equipment
a . Tektronix 7A15A and an 7A18
Amplifier (may be shared with an
7000-series test oscilloscope) .
b . Any 7A-series plug-in unit
(tol-
erances in some stpes
may be
lim-
ited
if low-frequency units used) .
a .
Tektronix 71353A
or 71352 Time
Base
.
b . Any 713-series plug-in unit
.
a . Tektronix Calibration Fixture
067-0587-01 .
b . Calibrated 7000-series plug-in
units with suitable signal sources
may be substituted if lower per-
formance is acceptable .
a . Tektronix P6053 or P6054
Probe (may be shared with test
oscilloscope) .
a .
Tektronix Part
No .
103-0030-00
.
a . Tektronix Calibration Fixture
067-0525-00 .
2- 3
Impedance, 50 ohms ; Used throughout pro- a . 'Tektronix Part No . 012-0076-00
type, RF-58/U ; length, 18 cedure for signal intercon- (18-inches) . Tektronix Part No .
and 42 inches ; connectors, nection . 012-0057-01 (42-inches) .
BNC
.
Impedance,
50 ohms ; External Z-axis operation a . Tektronix Part No . 017-0083-00 .
accuracy, ±2% ; connec- check . Vertical bandwidth
tors, GR874 input with check . Vertical amplifier
BNC male output . isolation check . Horizontal
bandwidth check .
Impedance, 50 ohms ; type External Z-axis operation a . Tektronix Part No . 017-0502-00 .
RG-213/U ; electrical check . Vertical bandwidth
length, five nanoseconds ; check . Vertical amplifier
connectors,
GR874 .
isolation check . Horizontal
bandwidth check .

Calibration-7623/R7623 Service
2- 4
NOTE
NO TE
NOTE
Three-inch
shaft, 3/32-
inch bit .
This
instrument should be adjusted at an
ambient
temperature of
+25 ° C ±5 ° C for best overall accuracy
.
1 . Remove the sides and bottom covers from the 7623
or the top cover and side panel from the
R7623 .
2 . Connect the instrument
to a power source that meets
the
voltage and frequency
requirements . The applied
voltage should be near the center
of the voltage range
marked on the rear panel (see Section
1 for information on
converting this instrument from one operating
voltage to
another) .
If correct line voltage is not available, use a
variable
autotransformer to provide the correct input
voltage .
3 . Set the controls as given under Preliminary
Control
Settings . Allow at least 20 minutes
warmup before pro-
ceeding .
Titles for external controls of this instrument are
capitalized in this procedure (e.g ., INTENSITY) .
Internal
adjustments are initial capitalized only (e.g .,
CRT Grid Bias) .
TEST EQUIPMENT (cont)
Usage
Added
operation check .
Trigger
source operation
check . Astigmatism
adjust-
ment .
Used throughout adjust-
ment procedure to adjust
variable resistors .
Used throughout adjust-
ment procedure to adjust
variable capacitors .
Vertical bandwidth check,
Storage writing rate check .
Preliminary Control Settings
Set the 7623 controls as follows :
INTENSITY
FOCUS
BEAM FINDER
GRATICULE ILLUM
VERT MODE
TRIG SOURCE
READOUT
NON-STORE
VAR
PERSIST
FAST
BI-STABLE
MULTI FAST
INTEG
SAVE
MANUAL
ERASE
AUTO ERASE
STORAGE LEVEL
STORED INTEN
AUTO VIEW TIME
(Persistance)
POWER
Examples of Applicable
Test Equipment
a . Tektronix Part No . 175-1178-00
(one supplied as standard acces-
sory) .
a . Xcelite R-3323
.
a . Tektronix
Part No . 003-0000-00 .
a .
Tektronix
Part No . 017-0064-00 .
Midrange
Adjusted for well-
defined display
Out
As desired
Left
VERT MODE
Midrange
In
Out
Out
Out
Out
Out
Out
Out
Out
Counterclockwise
Counterclockwise
Counterclockwise
in detent
ON

CALIBRATION PROCEDURE
7623 Serial No .
Calibration Date -
Calibrated By ___
Introduction
The following procedure
returns the 7623 to correct
calibration . All
limits and tolerances given in this procedure
are calibration
guides, and should not be interpreted as
instrument
specifications except as listed in Section 2 .
2-5
Calibration-7623/R7623 Service
16 .
Check Vertical Amplifier Bandwidth
Page 2-13
17 .
Check Vertical Amplifier Isolation
Page 2-14
18 .
Check Added Operation
Page 2-14
19 .
Check Alternate Operation
Page 2-14
20 .
Check Vertical Chopped Mode
Opera- Page 2-15
tion
Triggering System
21 . Check Trigger Source
Operation Page 2-16
Horizontal Deflection
System
22 . Adjust Horizontal
Amplifier Gain and Page 2-17
Low Frequency Linearity
23 . Adjust
Horizontal Amplifier Centering
Page 2-17
24
. Adjust Horizontal Amplifier Limit
Page 2-18
Centering
25 . Adjust High
Frequency Timing
Page 2-18
26 . Check X-Y
Phase Shift Page
2-19
27
. Check
Horizontal Bandwidth
Page
2-19
Z-Axis and
Auto Focus
28 . Adjust Z-Axis
Compensation
Page 2-20
29 . Adjust Auto
Focus Compensation and
Page
2-20
Operating
Levels
Calibrator
30 .
Adjust Calibrator Output Voltage
Page 2-21
31
. Check Calibrator
Repetition Rate Page
2-21
Signals Out
32 . Check SINGLE
SWEEP READY OUT
Page 2-22
33 . Check
EXT S S RESET IN
Page 2-22
34 . Check
VERT SIG OUT
Page
2-22
35 . Check +
SAWTOOTH OUT
Page 2-22
Index to Calibration
Procedure
Power Supply
1 . Adjust -50 Volt Power Supply
Page 2-7
2 . Check Remaining Power-Supply Voltages
Page 2-7
3 . Check High-Voltage Power Supply Page 2-8
Display and Z-Axis
4 .
Adjust
CRT Grid Bias
Page 2-9
5 . Adjust
Astigmatixm
Page 2-10
6
. Adjust
Trace Rotation Page
2-10
7 . Adjust
Y-Axis Alignment
Page 2-10
8 . Adjust Geometry
Page
2-10
9 . Check
External Z-Axis Operation
Page 2-11
10 . Check Beam Finder
Page 2-11
Vertical Deflection System
11 . Adjust Bias Adjustment
Page 2-12
12 . Adjust Vertical Centering
Page 2-12
13
. Check Vertical Gain Page 2-12
14 . Check Vertical Linearity Page
2-13
15
. Adjust Vertical
High-Frequency Com- Page 2-13
pensation

Calibration-7623/R7623 Service
36 . Check + GATE OUT Page 2-23
45 . Check ERASE and FAST Transfer Page 2-30
Pulses
Readout Operation
46 . Check High Speed Mesh Pump Pulses
Page 2-30
37 . Check READOUT SYSTEM Operation Page
2-24
47 . Check Pump Pulse Frequency
Page 2-30
38 . Check READOUT
Gate Triggered Oper- Page 2-24
ation
48 . Check/Adjust STORAGE LEVEL
Page 2-30
Range
Storage Operation
49 . Check FAST Writing Rate Page 2-31
39 . Check AUTO ERASE Function Page 2-25
50 . Check/Adjust FAST
Stability
Page 2-31
40 .
Check SAFE
Function Page 2-25
51 . Check/Adjust Variable Persistence
Mode
Page 2-31
41 . Check Readout Storage Operation
Page 2-26
and Voltage Levels
42 .
Check Storage Test Points
Page 2-27
52 .
Check/Adjust Variable Persistence Pulse Page 2-31
Amplitude
43 .
Adjust Bi-Stable Operating Level
Page 2-28
53 . Check/Adjust CE 2 and CE 3 Voltage
Page 2-32
44 . Check
Storage Test Points
Page 2-29
Levels

Equipment Required
1 . Precision DC voltmeter
2 . DC voltmeter (VOM)
3 . Three-inch screwdriver
Control Settings
Set
the controls as given in the
Preliminary Control
Settings .
1 .
Adjust -50 Volt Power
Supply
a . Set the
INTENSITY control
fully counterclockwise .
POWER
SUPPLY
Fig . 2-1 . (A) Location
of low-voltage and high-voltage test points
Iright side of instrument) (B)
Location of -50 V adjustment (Low
Voltage Regulator board) .
Calibration-7623/R7623 Service
b .
Connect the precision DC voltmeter between TP -50
(see
Fig
. 2-1
A)
and
chassis ground .
c . CHECK-Meter
reading ; -50 volts ±0 .1 volt .
d . ADJUST- -50
volts adjustment R881

(see
Fig . 2-1 B) for a meter
reading of exactly -50 volts .
e . INTERACTION-Change in
setting of R881 may
affect the operation of all circuits within the 7623 .
2 . Check Remaining
Power-Supply Voltages
a . CHECK-Table 2-1 lists
the low-voltage power
supplies in this instrument . Check
each supply with the
precision DC voltmeter for output voltage
within the given
tolerance
(connect meter ground lead to
chassis ground) .
Power supply test points are shown
in Fig . 2-1 A .
NOTE
Ripple and regulation
of the individual power
supplies can be
checked using the procedure given
under Troubleshooting
Techniques in Section 4 .
TABLE 2-1
Power Supply
Tolerance
2- 7
Power Supply
Test Point
Output Voltage
Tolerance
-50 Volt Pin 8 P1170
±0 .1 Volt
-15 Volt Pin 7 P1170 ±0 .1 Volt
+5 Volt Pin 5 P1170 ±0 .07 Volt
+15 Volt Pin 4 P1170
±0 .1 Volt
+50 Volt Pin 3
P1170 ±0 .3
Volt
+130 Volt Pin 2
P1170 ±5 .2
Volt

Calibration--7623/R7623 Service
3 . Check High-Voltage Power Supply

c . Pull out the power switch (turn on the instrument)
.
Check meter reading ; --1475 volts ±45 volts .
a . Push in the power switch (turn off the instrument) .
d . Push in the power switch (turn off the instrument)
.
Disconnect the DC voltmeter .
b . Set the DC voltmeter (VOM) to measure at least
1500 volts . Then, connect it between the high-voltage test
point (see Fig . 2-1 A) and chassis ground .

e .
Pull out the
power
switch (turn on the instrument) .