Tektronix 208 User manual

TEKTRONIX
( R )
208
STORAGE
MONITOR
WITH
OPTIONS
APRI
1975
SERVICE
INSTRUCTION
MANUAL
Tekt ronix ,
Inc.
P.O.
Box
500
Beaverton , Oregon
97077
Serial Num ber
070-1923-00 First Print ing MARCH 1975

H
WARRANTY
All TEKTRONIX inst rum ent s are warranted against
defective
m at erials and
workm anshi p
for
one year
.
Any quest ions wit h respect to the warranty should
be taken up wit h your TEKTRONIX Field Engineer or
representative
.
All
requests for
repairs and
replacem ent part s
should be directed to the TEKTRONIX Field Office
or representative in your area . This will assure you
the fast est possible service . Please include the
inst rum ent Type Num ber or Part Num ber and Serial
Num ber wit h all
requests for part s
or
service
.
Specifications and price change privileges reserved .
Copyright  1975 by Tekt ronix , Inc. , Beaverton ,
Oregon . Print ed in the Unit ed States of Am erica . All
right s
reserved .
Contents of this
publicat ion
m ay
not
be reproduced in any form wit hout perm ission of
Tekt ronix ,
Inc.
U.S.A. and foreign TEKTRONIX product s covered
by U.S. and
foreign patent s and / or
patent s pendi ng
.
TEKTRONIX is a regist ered t radem ark of Tekt ronix ,
Inc.

208
Service
TABLE
OF
CONTENTS
PAGE
vi
List of Illust rations
List
of
Tables
vii
SECTION 1
SAFETY
INFORMATION
AND
SPECIFICATIONS
1-1
Safety
Inform at ion
Power
Source
Safety
Specifications
1-1
1-2
SECTION
2
OPERATING
INFORMATION
Controls , Connect ors , and Indicators
2-1
Front
Panel
2-1
Rear Panel
2-2
2-3
Operating Power Inform at ion
Low Batt ery Indicator
Batt ery
Charging
2-3
2-4
2-4
2-5
Batt ery Replacem ent
AC Adapt er Connect ion
Operating
Tem perat ure
Hum idit y
2-5
2-5
SECTION
3
THEORY OF OPERATION
Sim pli fied
Block
Diagram
3-1
Power
Supply
3-1
3-1
3-1
3-1
ECG /
PULSE Am plifi ers and
Vertical
Am plifi er
Sweep
Generator
and
Horizont al
Am plifi er
Blanking Am plifi er
Erase , Storage , and Swit ching
Circuit
Description
ECG /
PULSE
and Audio
3-1
3-2
3-2
Circuit
Funct ions
3-2
3-3
3-3
ECG
and
Pulse
Am plifi ers
Float ing
Supply Oscillat or
Float ing Input Am plifi er
Current to Voltage Converter
ECG /
PULSE Swit ch
3-3
3-4
3-4
a
i

208
Operators
TABLE OF
CONTENTS
(
CONT
.
)
PAGE
SECTION
3
( CONT . )
AC - Coupled Am plifi er
3-4
Display
Am plifi er
3-4
Trace
Recovery
3-5
Audio Circuit
3-5
Audio Input Am plifi er
3-5
3-6
Free
-
Running
Multivibrat or
Audio
Output
Driver
3-6
Vertical and Horizont al Am plifi ers and Sweep
3-6
Circuit
Funct ions 3-6
Vertical
Am plifi er
3-6
Horizont al Am plifi er
3-6
Sweep
Generator
3-6
Erase
, Storage
,
and
Swit ching
3-7
Circuit Funct ions
3-7
Erase
and
Storage
3-7
Swit ching
3-7
3-10
3-10
3-11
Power Supplies and Crt
Circuit
Funct ions
Power
Supply
Prim ary
Oscillat or
Prim ary
Regulator
and
Low Voltage
Shutdown
Low Voltage Rect ifier and Regulator
High Voltage
Multiplier
3-11
3-11
3-11
3-11
3-11
Low Batt ery
Detect or
Run Current Am plifi er
3-11
Crt
Circuit ry
3-12
SECTION 4
MAINTENANCE
Prevent ive
Maintenance
4-1
Routine
Schedule
4-1
Operator
Inform at ion
4-1
4-1
External Cleaning
Inspect ion
4-1
ii
@

208
Service
TABLE
OF
CONTENTS (
CONT . )
PAGE
SECTION 4
(
CONT .
)
Service
Inform at ion
4-1
Cleaning
4-2
Calibration
4-2
4-2 Leakage Current
Check
Correct ive Maintenance
4-3
Tekt ronix Field
Service
4-3
4-3 Keeping a Service
Record
Soldering
Inform at ion
Obt aining Replacem ent Parts
4-3
4-3
Standard
Parts
4-3
Special
Parts 4-3
Ordering
Parts
4-3
Recalibrat ion
After Repair
4-3
Com ponent
Replacem ent
4-3
Tools
Required
4-5
Batt ery
Rem oval
4-5
Batt ery Replacem ent
4-5
Cabinet Top
Rem oval
4-5
4-5
4-5
4-5
Cabinet
Bottom
Rem oval
Cabinet
Replacem ent
Interconnecting Cable and Term inal Connect or
Replacem ent
ECG
Board
Rem oval
ECG
Board
Replacem ent
Storage
Board
Rem oval
Storage Board
Replacem ent
4-6
4-6
4-6
4-6
Audio
Board
Rem oval 4-6
Audio
Board
Replacem ent
4-6
4-6
4-7
Front Panel or Im plosion Shield Rem oval
Front Panel
or
Im plosion Shield
Replacem ent
Cent ral Interconnected Group Rem oval
Cent ral
Interconnected
Group Replacem ent
4-7
4-7
Main
Board Rem oval
4-8
Main
Board
Replacem ent
4-8
@
iii

208 Service
TABLE OF CONTENTS ( CONT . )
PAGE
SECTION
4
( CONT . )
Fuse
Replacem ent
4-8
4-8
Push Butt on Swit ch
Rem oval (
DISPLAY Push
Butt on Swit ches Only )
Push Butt on
Swit ch
Replacem ent
4-10
Light
Em it ting
Diode (
LED )
Rem oval
4-10
4-11
4-11
4-11
LED
Replacem ent
Circuit
Board Term inal
Pin and
Term inal Pin
Socket
Replacem ent
Sem iconduct or
Replacem ent
Troubleshooting
Troubleshooting Equipm ent
Troubleshooting
Aids
Diagram s
4-12
4-12
4-12
4-12
Circuit Boards
4-12
4-12
Sem iconduct or Lead Configurat ion
Troubleshooting
Procedure
Inst rum ent
Repackaging
4-12
4-16
SECTION 5
CALIBRATION
Calibration Interval
5-1
Test Equipm ent Required
5-1
Special
Test
Accessories
5-1
5-1
5-1
Equipm ent
Required
Index to
Calibration
Procedure
Prelim inary Test Setup
Calibration
Procedure
5-2
5-3
SECTION 6
INSTRUMENT
OPTIONS
SECTION 7
REPLACEABLE ELECTRICAL PARTS
iv

208 Service
TABLE
OF
CONTENTS (
CONT . )
PAGE
SECTION 8
DIAGRAMS
&
CIRCUIT
BOARD
ILLUSTRATIONS
SECTION 9
REPLACEABLE
MECHANICAL
PARTS
SECTION 10
ACCESSORIES
CHANGE
INFORMATION

208 Service
LIST OF ILLUSTRATIONS
FIGURE NO .
PAGE
Front ispiece
208
Storage Monit or .
viii
1-1
Dim ensional
drawing .
1-7
2-1
Front
panel .
2-1
2-2
Partial
front
panel
.
2-2
2-3
Rear
panel
.
2-3
2-4
2-4
2-5
2-5
3-1
3-2
Batt ery
replacem ent .
AC Adapt er
connect ed to
m onit or
.
Sim pli fied block diagram .
Audio circuit sim pli fied diagram .
Erase and Storage t im ing diagram .
Swit ching circuit sim pli fied diagram .
3-2
3-5
3-3
3-8
3-4
3-9
4-1
Board locator .
4-4
4-2
Term inal
connect ors .
4-5
4-3
Push - but t on swit ch rem oval and re - inst allat ion .
4-9
4-4
4-10
LED
replacem ent
.
Power
supplies
referenced
to +5.6
volt s .
4-5
4-14
4-6
Power
supplies
referenced to
-7 volt s .
4-14
4-7
Power
supplies
referenced
to -7
volt s .
4-15
5-1
5-3
Operating
current test
setup .
Test setup
for m easuring
gain . 5-2
5-5
5-3
ECG test cable
.
5-6
5-4
Signal
out
cable
.
5-6
5-5
5-9
5-6
5-11
5-7
5-12
Test setup for
adjust ing
charge
offset .
Display
of
sim ulat ed
pacer
pulse
baseline
offset .
Typical
display
of sag for
inst rum ent s
wit h Audio
board .
Typical
display
of sag
for
inst rum ent s wit hout
Audio
board .
Typical
display
of sag for
inst rum ent s
wit hout
Audio
board .
Test
setup to
check
Lead
Fault .
5-8
5-12
5-9
5-12
5-10
5-13
5-11
CMRR test fi xt ure
.
5-13
5-12
Test
setup to m easure
leakage
at 120 volt s
ac .
5-14
Sect ion 8 fi gures are located near their associated diagram on the
foldout
pages
.
Sem iconduct or lead configurations .
8-1
8-2
ECG board adjust m ent locations and test points .
vi

208 Service
LIST
OF
ILLUSTRATIONS
(
CONT
. )
FIGURE NO .
PAGE
8-3
8-4
8-5
8-6
8-7
8-8
8-9
8-10
Swit ch
board
test
points .
Storage board adjust m ent locations and test points .
Main
board adjust m ent
locations and test
points
.
Block
diagram
.
A1
ECG
circuit
board
.
A6 Audio circuit board .
ECG
board volt age and
waveform test
points .
A2 Main circuit board .
A4 Swit ch circuit board .
Main
board volt age and
waveform test
points
.
A3 Storage circuit board .
A2 Main circuit board .
A5 Batt ery Interface circuit board .
Main board volt age and waveform test points .
Troubleshooting chart .
8-11
8-12
8-13
8-14
8-15
8-16
8-17
10-1
10-2
10-2
Monit or holder m ount ing kit inst allat ion .
Monit or
holder
inst allat ion
.
ECG
cable
.
10-2
10-3 10-3
10-4
Pulse
sensor
.
10-3
LIST OF TABLES
TABLE NO .
PAGE
1-1
1-2
1-2
1-5
1-3
1-6
2-1
2-4
Electrical
Environm ent al
Physical
Typical Derat ing of Operating Tim e for Various Charge and
Operating
Tem perat ures
Routine Maintenance Schedule
Power Supply Operating Tolerance
Internal
Supplies
Option Inform at ion Locator
4-1
4-1
4-2
4-13
5-1
5-4
6-1
6-2
vii

208 Service
TEKTRONIX
SIZE
DISPLAY
SAVE
/
SEC
12.5
25.0
FULL
SPLIT
LOW
BATT
PWR
ON
OFF
SAVE
LEAD
FAULT
POS
PULSE
ECG
RE
2012
$
50
L.
NEART
RATE
BEATS
PER
MIN
AT
25m m
/
SEC
1923-03
208
Storage Monit or .
viii