Tektronix 442 User manual

Tektronix
COMMITTED TO EXCELLENCE
WARNING
THE FOLLOWING SERVICING INSTRUCTIONS ARE
FOR USE BY QUALIFIED PERSONNEL ONLY. TO
AVOID PERSONAL INJURY, DO NOT PERFORM ANY
SERVICING OTHER THAN THAT CONTAINED IN
OPERATING INSTRUCTIONS UNLESS YOU ARE
QUALIFIED TO DO SO.
INSTRUCTION MANUAL
Tek ronix, Inc.
P.O. Box 500
Beaver on, Oregon 97077 Serial Number
070-2374-01 Firs Prin ing AUG 1977

WARRANTY
.Tek ronix warran s ha his produc is free from defec s in ma erials
and workmanship. The warran y period is one (1) year from he da e
of shipmen . Tek ronix will, a i s op ion, repair or replace he
'.produc if Tek ronix de ermines i is defec ive wi hin he warran y
' period and if i is re urned, freigh prepaid, o a service cen er
„ /. designa ed by Tek ronix.
Tek ronix is no obliga ed o furnish service under his warran y:
a. o repair damage resul ing from a emp s by personnel o her
han Tek ronix represen a ives o ins all, repair, orseVyipe he
produc ;
b. o repair damage resul ing from improper.’use or. from
connec ing he produc o incompa ible equipmen ;
' - ' c if personnel o her han Tek ronix represen a ives modify he
hardware or sof ware. -
There is no implied warranty of fitness for a particular purpose.
Tek ronix is no lia le for consequential damages.
Copyrigh © igZTi f 980 Tek ronix, Inc. All righ s reserved.
Con en s of his publica ion may no be reproduced in any
form wi hou he wri en permission of Tek ronix, Inc.
Produc s of Tek ronix, Inc. and i s subsidiaries are
covered by U S. and foreign pa en s and/or pending
pa en s.
TEKTRONIX, TEK. SCOPE-MOBILE, and S are reg
is ered rademarks of Tek ronix, inc. TELEQUIPMENTis
a regis ered rademark of Tek ronix U.K. Limi ed.
Prin ed in U.S.A. Specifica ion and price change
privileges are reserved.

442 Service
TABLE OF CONTENTS
Page
LIST OF ILLUSTRATIONS ................................... ii
LIST OF TABLES................................................... iv
SAFETY SUMMARY .............................................. v
Section 1 SPECIFICATION ................................ 1-1
ELECTRICAL CHARACTERISTICS . . 1-1
ENVIRONMENTAL
CHARACTERISTICS ......................... 1-4
PHYSICAL CHARACTERISTICS .... 1-5
ACCESSORIES................................... 1-5
Section 2 OPERATING INSTRUCTIONS............ 2-1
INTRODUCTION ................................ 2-1
INSTALLATION................................... 2-1
CONTROLS, CONNECTORS, AND
INDICATORS ....................................... 2-3
BASIC OSCILLOSCOPE OPERATION 2-8
Section 3 THEORY OF OPERATION ................ 3-1
GENERAL............................................ 3-1
BLOCK DIAGRAM DESCRIPTION . . . 3-1
DETAILED CIRCUIT DESCRIPTION . 3-2
VERTICAL INPUT ......................... 3-2
VERTICAL SWITCHING ................ 3-3
VERT OUTPUT AM PL, CRT, &
PROBE ADJ .................................. 3-5
TRIGGER ....................................... 3-6
SWEEP AND HORIZONTAL
AMPLIFIER ..................................... 3-8
HORIZONTAL OUTPUT AMPLIFIER 3-9
POWER SUPPLY............................ 3-9
Page
Sec ion 4 CALIBRATION PROCEDURE............ 4-1
GENERAL............................................ 4-1
In roduc ion..................................... 4-1
Tes Equipmen Required .............. 4-1
PERFORMANCE CHECK .................. 4-3
In roduc ion..................................... 4-3
Preliminary Procedure .................. 4-4
Procedure ....................................... 4-5
ADJUSTMENT PROCEDURE............ 4-12
In roduc ion..................................... 4-12
Preliminary Procedure ................... 4-14
A. DISPLAY AND POWER SUPPLY 4-17
B. VERTICAL AMPLIFIER .............. 4-19
C. HORIZONTAL............................ 4-23
D. TRIGGERING ............................ 4-25
Sec ion 5 MAINTENANCE .................................. 5-1
INTRODUCTION ................................ 5-1
PREVENTIVE MAINTENANCE ........... 5-2
TROUBLESHOOTING ....................... 5-4
CORRECTIVE MAINTENANCE ......... 5-12
Section 6 REPLACEABLE ELECTRICAL PARTS
Section 7 DIAGRAMS & CIRCUIT BOARD
ILLUSTRATIONS
Section 8 REPLACEABLE MECHANICAL PARTS
REV A MAY 1980

442 Service
LIST OF ILLUSTRATIONS
Fig-
No. Page
442 Oscilloscope ....................................... viii
1- 1 442 Oscilloscope dimensions.................... 1-6
2- 1 Commonly used power plugs ................. 2-2
2-2 Power swi ch loca ions on bo om of he
442 ............................................................ 2-2
2-3 Power inpu fuse loca ion on he 442 back
panel.......................................................... 2-3
2-4 Cr Display and Power fron panel con rols
and connec ors ....................................... 2-3
2-5 Ex ernal Z AXIS INPUT connec or on he
back panel of he 442 .............................. 2-4
2-6 Con rols and swi ches accessible hrough
he bo om of he 442 cabine ................ 2-5
2-7 Ver ical sys em con rols.......................... 2-5
2-8 Horizon al sys em con rols ..................... 2-6
2-9 Triggering sys em con rols ..................... 2-7
2-10 Probe Compensa ion . . ........................... 2-9
2-11 Display of 0.5 V PROBE ADJ ou pu signal 2-10
2-12 Measuring peak- o-peak vol age of a
waveform................................................... 2-11
2-13 Measuring ins an aneous dc vol age wi h
respec o a reference vol age ................ 2-11
2-14 Measuring he ime dura ion be ween
poin s on a waveform .............................. 2-14
2-15 Measuring rise im e ................................. 2-15
2-16 Measuring ime difference be ween wo
pulses ....................................................... 2-15
2-17 Measuring phase difference...................... 2-16
2- 18 Phase difference measuremen wi h an X-Y
display ..................................................... 2-17
3- 1 Sweep genera or and sweep ga e iming
diagram..................................................... 3-9
3- 2 Foldback circui ac ion ............................. 3-10
4- 1 Ver ical deflec ion accuracy es se up . . 4-5
4-2 Bandwid h check es se up ...................... 4-7
4-3 Triggering and Z-Axis inpu .check es
se up ......................................................... 4-9
4-4 Timing accuracy check es se up .......... 4-11
4-5 442 cabine removal ................................. 4-13
4-6 Moving In erface board o adjus men
access posi ion ....................................... 4-15
4-7 Low-vol age power supply adjus men
loca ion..................................................... 4-17
Fig.
No. Page
4-8 In erface board adjus men loca ions
(board shown in access posi ion) ........... 4-18
4-9 Ver ical a enua or, preamplifier, delay line
driver, and CH 2 dc rigger level adjus men
loca ions................................................... 4-21
4-10 Display of correc (idealized) a enua or
compensa ion .......................................... 4-21
4-11 Horizon al adjus men loca ions on A14
Horizon al Ou pu board.......................... 4-23
4-12 Horizon al adjus men loca ions on A12
Horizon al board and A ll Trigger Swi ch
board ....................................................... 4-24
4- 13 Triggering and X-Axis adjus men loca ions
on he A11 Trigger Swi ch board............ 4-26
5- 1 Cabine removal ........................................ 5-1
5-2 Moving In erface board o access posi ion 5-3
5-3 Color codes............................................... 5-5
5-4 Semiconduc or lead configura ion .......... 5-6
5-5 Mul i-pin connec or holder indexing .... 5-7
5-6 Pin connec or re-ins alla ion in mul i-pin
holders ..................................................... 5-15
5-7 Shaf -knob assembly removal ................. 5-17
5-8 A enua ors, A enua or Shif , Horizon al
Ou pu , and Power Supply assembly
removal..................................................... 5-17
5-9 In erface, Trigger Swi ch, Horizon al, and
Timing (SEC/DIV swi ch) assemblies
removal..................................................... 5-19
The following illustrations are located on foldout
pages in Section 7 Diagrams and Circuit Board
Illustrations.
7-1 A6—CH 1 A enua or circui board
componen loca ions
7-2 A7—CH 2 A enua or circui board
componen loca ions
7-3 A enua or circui board loca ions
7-4 442 Oscilloscope block diagram
7-5 A8—Ver ical circui board componen
loca ions
7-6 Ver ical circui board loca ion
ii REV A MAY 1980

442 Service
LIST OF ILLUSTRATIONS (cont)
Fig. Fig.
No. No.
7-7 A1—In erface circui board componen 7-11 A12—Horizon al circui board loca ions
loca ions 7-12 Horizon al circui board loca ion
7-8 In erface circui board loca ion 7-13 A14—Horizon al Ou pu circui board
7-9A All-Trigger Swi ch circui board componen loca ions
componen loca ions for SN B021532 and 7-14 Horizon al Ou pu board loca ion
up 7-15 A2—Power Supply circui board
7-9B All—Trigger Swi ch circui board componen loca ions
componen loca ions for SN below 7-16 Power Supply board loca ion
B021532 7-17 442 Oscilloscope roubleshoo ing char
7-10 Trigger Swi ch circui board loca ion
REV A MAY 1980 iii

LIST OF TABLES
442 Service
Ta le
No. Page
1-1 Elec rical Charac eris ics ................... 1-1
1-2 Environmen al Charac eris ics .......... 1-4
1- 3 Physical Charac eris ics ..... 1-5
2- 1 Power Cord Conduc or Iden ifica ion ... 2-1
2-2 Ac Regula ing Ranges ............................ 2-2
2- 3 Power Inpu Fuse Values ..... 2-2
3- 1 A enua or and Gain Swi ching Sequence 3-3
4- 1 Tes Equipmen Required ... 4-1
4-2 Ver ical Deflec ion Accuracy ............ 4-5
4- 3 Sweep Ra e Timing Accuracy . 4-10
5- 1 Power Supply Tolerance ..... 5-8
5-2 Rela ive Suscep ibili y o S a ic Discharge
Damage............................................. 5-13
5-3 Main enance Aids ............................. 5-23
iv REV A MAY 1980

442 Service
OPERATORS SAFETY SUMMARY
The general safe y informa ion in his par of he summary
is for bo h opera ing and servicing personnel. Specific
warnings and cau ions will be found hroughou he
manual where hey apply, bu may no appear in his
summary.
Terms In This Manual
CAUTION s a emen s iden ify condi ions or prac ices ha
could resul in damage o he equipmen or o her proper y.
WARNING s a emen s iden ify condi ions or prac ices
ha could resul in personal injury or loss of life.
Terms As Marked on Equipment
CAUTION indica es a personal injury hazard no im
media ely accessible as one reads he marking, or a
hazard o proper y including he equipmen i self.
DANGER indica es a personal injury hazard immedia ely
accessible as one reads he marking.
Sym ols In This Manual
A This symbol indica es where applicable
cau ionary or o her informa ion is o be
found.
Sym ols As Marked on Equipment
DANGER — High vol age.
Pro ec ive ground (ear h) erminal.
A ATTENTION — refer o manual.
Power Source
This produc is in ended o opera e from a power source
ha will no apply more han 250 vol s rms be ween he
supply conduc ors or be ween ei her supply conduc or
and ground. A pro ec ive ground connec ion byway of he
grounding conduc or in he power cord is essen ial for
safe opera ion.
Grounding the Product
This produc is grounded hrough he grounding conduc
or of he power cord. To avoid elec rical shock, plug he
power cord in o a properly wired recep acle before
connec ing o he produc inpu or ou pu erminals. A
pro ec ive ground connec ion by way of he grounding
conduc or in he power cord is essen ial for safe opera
ion.
Danger Arising From Loss of Ground
Upon loss of he pro ec ive-ground connec ion, all
accessible conduc ive par s (including knobs and con
rols ha may appear o be insula ing) can render an
elec ric shock.
Use the Proper Power Cord
Use only he power cord and connec or specified for your
produc .
Use only a power cord ha is in good condi ion.
For de ailed informa ion on power cords and connec ors,
see Opera ing Ins ruc ions sec ion.
Refer cord and connec or changes o qualified service
personnel.
Use the Proper Fuse
To avoid fire hazard, use only he fuse of correc ype,
vol age ra ing and curren ra ing as specified in he par s
lis for your produc .
Refer fuse replacemen o qualified service personnel.
Do Not Operate in Explosive Atmospheres
To avoid explosion, do no opera e his produc in an
explosive a mosphere unless i has been specifically
cer ified for such opera ion.
Do Not Remove Covers or Panels
To avoid personal injury, do no remove he produc
covers or panels. Do no opera e he produc wi hou he
covers and panels properly ins alled.
REV A MAY 1980 V

442 Service
SERVICE SAFETY SUMMARY
FOR QUALIFIED SERVICE PERSONNEL ONLY
efer also to the preceding Operators Safety Summary.
Do Not Service Alone
Do no perform in ernal service or adjus men of his
produc unless ano her person capable of rendering firs
aid and resusci a ion is presen .
Use Care When Servicing With Power On
Dangerous vol ages exis a several poin s in his produc .
To avoid personal injury, do no ouch exposed connec
ions and componen s while power is on.
Disconnec power before removing pro ec ive panels,
soldering, or replacing componen s.
Power Source
This produc is in ended o opera e from a power source
ha will no apply more han 250 vol s rms be ween he
supply conduc ors or be ween ei her supply conduc or
and ground. A pro ec ive ground connec ion by wayof he
grounding conduc or in he power cord is essen ial for
safe opera ion.
REV A MAY 1980 vii

442 Service
442 Oscilloscope.
viii REV A MAY 1980

Section 1—442 Service
SPECIFICATION
This manual con ains a specifica ion, opera ing in
s ruc ions, and service informa ion per aining o he
TEKTRONIX 442 Oscilloscope. The 442 is a por able,
35 MHz, dual race ins rumen wi hachoiceof al erna eor
chop sweep presen a ion on a single ime base. The
Ver ical Amplifier provides calibra ed deflec ion fac ors
from 2 mV o 10 V/div. The Time Base provides s able
riggering over he full bandwid h of he Ver ical Amplifier
and provides calibra ed sweep ra es from 0.5 s/div o
0.1 yus/div. A XI0 magnifier swi ch ex ends he fas es
sweep ra e o 10 ns/div.
The following ins rumen specifica ion applies over an
ambien empera ure range of -15° o +55°C for in
s rumen s ha have been calibra ed a an ambien
empera ure be ween +20° C and +30° C unless o herwise
i ndi ca ed when he i ns rumen has had a warm up peri od of
abou 20 minu es. The adjus men procedure in Sec ion 4,
when performed comple ely, allows he 442 o mee he
elec rical specifica ion lis ed in Table 1-1.
Ta le 1-1
ELECTRICAL CHARACTERISTICS
Characteristics Performance Requirements Supplemental Information
VERTICAL SYSTEM
Deflec ion Fac or
Calibra ed Range 2 mV o 10 V/div; 12 s eps,
in a 1-2-5 sequence.
Accuracy
+20° C o +30° C Wi hin 3%. Gain adjus ed wi h VOLTS/DIV
swi ch se o 2 m.
—15°C o +55° C Wi hin 4%.
Uncalibra ed (VAR)
Range Con inuously variable be ween
se ings. Increases deflec ion fac or
by approxima ely 2.5:1.
Ex ends maximum deflec ion fac or
o a leas 25 V/div.
Frequency Response
Bandwid h
2 m o 1 V Dc o a leas 35 MHz.
5-division reference signal
cen ered ver ically from a
25 O sourse wi h VOLTS/DIV
VAR con rol in calibra ed de en .
2 V, 5 V, & 10 V Dc o a leas 25 MHz.
Chopped Mode Repe i ion Rae Approxima ely 250 kHz.
Inpu Resis ance Approxima ely 1 MQ.
Inpu Capaci ance Approxima ely 30 pF.
Maximum Inpu Vol age 400 V (dc + peak ac).
800 V p-p ac a 1 kHz or less.
REV A MAY 1980 1-1

Specification—442 Service
Ta le 1-1 (cont)
Characteristics Performance Requirements Supplemental Information
VERTICAL SYSTEM (con )
CMRR (DIFF Mode) A leas 10:1 a 1 MHz in
10 mV/div (IX window) posi ion
for common mode signals of
8 divisions or less wi h gain
adjus ed for bes CMRR a
50 kHz.
HORIZONTAL DEFLECTION SYSTEM
Sweep Ra e
Calibra ed Range 0.5 s o 0.1 jus/div; 21 s eps
in a 1-2-5 sequence.
Uncalibra ed (VAR)
Range Con inuously variable be ween
calibra ed se ings. Decreases
sweep ra e by a leas 2.5:1.
Ex ends slowes sweep ra e o
a leas 1.25 sec/div.
Accuracy
+20° C o +30° C
Sweep accuracy applies over he
cen er 8 divisions. Exclude he firs
50 ns of sweep for bo h magnified
and unmagnified sweep ra es as well
as any hing beyond he 100 h
magnified division.
Unmagnified Wi hin 3%.
Magnified Wi hin 5%.
—15°C o +55° C
Unmagnified Wi hin 4%.
Magnified Wi hin 6%.
X10 Magnifier Ex ends fas es sweep ra e
o 10 ns/div. 10:1 (in X10 posi ion— wi h bu on pressed in— he sweep
ra e is one en h of ha indica ed
for he SEC/DIV swi ch se ing).
X-Y Opera ion
X-Axis Deflec ion
Accuracy 5-division reference signal.
+20° C o +30° C ±5% (MAGNIFIER in XI only).
-15°C o +55° C ♦±6% (MAGNIFIER in XI only).
Sensi ivi y Same as for Channel 1 and
Channel 2 Calibra ed Deflec ion
Fac or Range (MAGNIFIER in XI
only).
1-2 REV A MAY 1980

Ta le 1-1 (cont)
Specification—442 Service
Characteristics Performance Requirements Supplemental Information
VERTICAL SYSTEM (con )
X-Axis Bandwid h Dc o a leas 2 MHz. 5-division reference signal.
Inpu Resis ance Approxima ely 1 Mfi.
Inpu Capaci ance Approxima ely 30 pF.
Maximum Inpu Vol age 400 V (dc + peak ac).
800 V p-p ac a 1 kHz or less.
TRIGGERING SYSTEM
Sensi ivi y
AC CPLG
(AUTO & NORM) 0.5 div in ernal or 100 mV
ex ernal from 60 Hz o 2 MHz,
increasing o 1.5 div in ernal
or 150 mV ex ernal a 35 MHz.
EXT/10 requiremen s are approxi
ma ely en imes he values
lis ed for EXT.
DC CPLG
(AUTO & NORM) 0.5 div in ernal or 100 mV ex ernal from dc o 2 MHz,
increasing o 1.5 div in ernal
or 150 mV ex ernal a 35 MHz.
TV Sync Composi e sync 1 div in ernal
or 100 mV ex ernal. Composi e
video approxima ely 2.3 div
in ernal or 230 mV ex ernal.
Ex ernal Trigger Inpu
(EXT & EXT/10)
Maximum Inpu Vol age 400 V (dc + peak ac).
800 V p-p ac (1 kHz or less).
Inpu Resis ance Approxima ely 1 MD.
Inpu Capaci ance Approxima ely 30 pF.
LEVEL Range
EXT -0.5 V o +0.5 V.
EXT/10 -5 V o +5 V.
PROBE ADJUST SIGNAL
Ou pu Vol age Approxima ely 0.5 V.
Repe i ion Ra e Approxima ely 1 kHz.
Z-AXIS INPUT
Sensi ivi y 5 vol s causes no iceable
modula ion.
REV A MAY 1980 1-3

Specification—442 Service
Ta le 1-1 (cont)
Characteristics Performance Requirements Supplemental Information
Z-AXIS INPUT (con )
Usable Frequency Range Dc o 5 MHz.
Maximum Inpu Vol age 30 V (dc + peak ac). 30 V p-p
ac a 1 kHz or less.
Inpu Impedance Approxima ely 10 kQ.
DISPLAY
Display Area 8X10 cm.
Trace Ro a ion Range Adequa e o align race wi h
cen er horizon al gra icule line.
S andard cr Phosphor P31.
Nominal Anode Vol age Approxima ely +10 kV.
POWER SOURCE
Line Vol age Ranges, ac 120 V/240 V & HI/LO swi ches
are accessible ex ernally.
120 V Range HI—110 o 132 V rms.
LO—92 o 110 V rms.
240 V Range HI—220 o 250 V rms.
LO—202 o 242 V rms.
Line Frequency 48 o 62 Hz.
Power Consump ion 36 wa s (max); 0.35 amps (max)
a 120 V, 60 Hz.
Ta le 1-2
ENVIRONMENTAL CHARACTERISTICS
Characteristics Description
Tempera ure
Opera ing -15°C o +55°C.
Non-opera ing -55° C o +75° C.
Al i ude
Opera ing To 15,000 fee. Maximum opera ing empera ure decreased 1°C/1000 fee
above 5000 fee .
Non-opera ing To 50,000 fee .
1-4 REV A MAY 1980

Specification—442 Service
Ta le 1-2 (cont)
Characteristics Description
Humidi y
Opera ing and Non-opera ing 5 cycles (120 hours) referenced o MIL-E-16400F.
Vibra ion (Opera ing) 15 min along each of 3 major axes a a o al displacemen of 0.025” p-p
(4 g’s a 55 Hz) wi h frequency varied from 10 Hz o 55 Hz o 10 Hz in
one minu e sweeps. Hold for hree minu es a 55 Hz. All major resonances
mus be above 55 Hz.
Shock
Opera ing and Non-opera ing 30 g’s, 1/2 sine, 11 ms dura ion, 2 shocks per axis each direc ion for
a o al of 12 shocks.
Ta le 1-3
PHYSICAL CHARACTERISTICS
Characteristics Description
Weigh
Wi h Panel Cover, Accessories, and
Accessories Pouch 22.5 pounds (10.1 kilograms).
Wi hou Panel Cover, Accessories,
and Accessory Pouch 18.0 pounds (8.1 kilograms).
Domes ic Shipping Weigh 28.5 pounds (12.95 kilograms).
Dimensions Refer o Figure 1-1.
ACCESSORIES
NOTE
efer to the Accessories tab page in the eplaceable
Mechanical Parts list for further information about
accessories listed here.
Standard Accessories Optional Accessories
1 Opera ors Manual Pro ec ive Wa erproof Cover
1 Service Manual Clear Ligh Fil er
2 10X Probes
1 Fron Cover
1 Accessory Pouch
REV A MAY 1980 1-5

Specification—442 Service
FRONT
VIEW
5.60 INCHES
(14.22 cm)
11.25 INCHES
(28.57 cm)
12.95 INCHES
(32.89 cm)
2374-2 A
Figure 1-1. 442 Oscilloscope dimensions.
1-6 REV A MAY 1980

Section 2—442 Service
OPERATING INSTRUCTIONS
INTRODUCTION
The TEKTRONIX 442 Oscilloscope is a 35 MHz maximum bandwid h ins rumen wi h dual race capabili y. A dual
race dc o 35 MHz ver ical sys em provides calibra ed deflec ion fac ors from 2 mV/div o 10 V/div. Triggering circui s
provide s able riggering over he full ver ical bandwid h. A horizon al deflec ion sys em provides calibra ed sweep ra es
from 0.5 s/div o 0.1 //s/div. A X10 magnifier circui (push-bu on swi ch) ex ends maximum sweep o 10 ns/div. In X-Y
mode of opera ion, ver ical and horizon al deflec ion fac ors are he same as for he ver ical amplifiers.
INSTALLATION
Unpacking
The 442 is shipped in i s car on wi h he s andard
accessories lis ed on he Accessories ab page a he end
of his manual. A ins alla ion ime, save he shipping
car on and packaging ma erials for repackaging. Refer o
he end of his sec ion for repackaging informa ion.
Line Voltage Selection
WARNING!
This instrument is designed for operation from a
power source with its neutral at or near earth
(ground) potential with a separate safety-earth
conductor.
Safety Considerations
This instrument may be damaged if operated with
the Line Voltage Selector switch or the egulating
ange Selector switch set for the wrong applied line
voltage or if the wrong line fuse is used.
Refer o he Safe y Summary in he fron of his manual
for power source, grounding, and o her safe y con
sidera ions per aining o use of he ins rumen . Before
connec ing he ins rumen o a power source, verify ha
he Line Vol age Selec or swi ch and he Regula ing
Range Selec or swi ch are bo h se for he line vol age
being used, ha he proper line fuse is ins alled, and ha
he line cord plug ma ches he power source o be used.
The 442 is designed o be used wi h a hree-wire ac
power sysem. If a hree- o- wo wire adap er is used o
connec his ins rumen o a wo-wire ac power sys em, be
sure o connec he ground lead of he adap er o ear h
(ground). Failure o comple e he ground sys em may
allow he chassis of his ins rumen o be eleva ed above
ground po en ial, hus posing a shock hazard.
The power cord plug may require replacemen wi h a
ype ma ching he power source. If necessary, change he
line cord plug. Refer o Table 2-1 for power cord conduc
or iden ifica ion and o Figure 2-1 for illus ra ions of
commonly-used power plugs.
Ta le 2-1
POWER CORD CONDUCTOR IDENTIFICATION
Conductor Color Alternate
Color
Ungrounded (Line) Brown Black
Grounded (Neu ral) Blue Whi e
Grounding (Ear hing) Green-Yellow Green-Yellow
The 442 opera es from ei her 92 o 132 V or 202 o 250 V
ac inpu a 48 o 62 Hz. A 120 or 240 V Line Vol age
Selec ion swi ch and aHI/LO Regula ing Range swi ch are
loca ed on he bo om of he ins rumen and are screw
driver ac ua ed hrough openings in he cabine .
REV A MAY 1980 2-1

Operating Instructions—442 Service
NORTH AMERICAN
120 VOLT/60 Hz
RATED 15 AMPERE
(12 AMP MAX.; NEC)
UNIVERSAL EURO
220 VOLT/50 Hz
RATED 16 AMPERE
240 VOLT/60 Hz
RATED 15 AMPERE
(12 AMP MAX.; NEC)
U.K.
240 VOLT/50 Hz
RATED 13 AMPERE
AUSTRALIAN
240 VOLT/50 Hz
RATED 10 AMPERE
(2 389-7 6)2757-66
AC LINE VOLTAGE HI/LO
SELECTION (120 V/240 V) /
\/
Figure 2-2. Power switch locations on ottom of the 442.
Ta le 2-2
AC REGULATING RANGES
HI/LO
Switch
Position 120 V/240 V Setting
120 V 240 V
HI 110 o 132 V rms 220 o 250 V rms
LO 92 o 110 V rms 202 o 240 V rms
Fuse Information
The 442 power inpu fuse is loca ed in a fuse holder on
he back panel of he 442. See Figure 2-3.
Figure 2-1. Commonly used power plugs.
Se he AC Line Vol age Selec ion syvi ch o he nominal
line vol age available (see Table 2-2). The fuse value mus
be changed when a differen Line Vol age range is
selec ed (see Table 2-3).
Se he HI/LO Regula ing Range swi ch (see Figure 2-2)
so he expec ed line-vol age fluc ua ions remain wi hin
he range selec ed (see Table 2-2).
Ta le 2-3
POWER INPUT FUSE VALUES
Applied Voltage F700 Value
120 V ac 0.75 A Fas Blow
240 V ac 0.30 A Slow Blow
2-2 REV A MAY 1980

Operating Instructions—442 Service
Figure 2-3. Power input fuse location on the 442 ack panel.
CONTROLS, CONNECTORS, AND
INDICATORS
Introduction
The following informa ion will familiarize an opera or
wi h he loca ion and opera ion of ex ernal con rols,
connec ors, and indica ors. These con rols, connec ors,
and indica ors are accessible from ou side he ins rumen
wi h i s cabine in place. In ernal con rols should no be
adjus ed excep during ins rumen calibra ion and ser
vice. Calibra ion and service procedures mus be referred
o qualified personnel.
Figure 2-4. Crt Display and Power front panel controls and
connectors.
@ BEAM FINDER
Spring-loaded push-bu on swi ch o loca e off
screen displays. When he BEAM FINDER bu on
is pressed in, he cr display is elec rically com
pressed o wi hin he gra icule area, independen
of posi ion con rol se ings or applied signals. To
loca e an off-screen display:
a. Se ver ical POSITION and INTENSITY con
rols o midrange and ro a e he horizon al
POSITION con rol fully clockwise.
Crt Display and Power
(Fron Panel. See Figure 2-4.)
(? ) ASTIGmatism
Recessed screwdriver con rol used in conjunc
ion wi h he FOCUS con rol o ob ain a well-
defined display. I does no require readjus men
during normal opera ion of he 442.
(T ) INTENSITY
Turn con rol clockwise o increase display
brigh ness. Se for lowes visible display o
prolong cr life.
(T ) FOCUS
Provides adjus men for op imum display defini
ion when INTENSITY and sweep speed se ings
are changed significan ly (also see ASTIG).
b. If a display or do s ill is no visible, press
BEAM FINDER and hold in. A compressed dis
play or do should appear. If no, increase
INTENSITY un il a do or display appears.
If a do or ver ical line appears, he sweep is no
riggered. Se rigger MODE swi ch o AUTO and
ob ain a display. Cen er he display wi h ver ical
and horizon al POSITION con rols. Release
BEAM FINDER push bu on and adjus rigger
LEVEL con rol for a s able display.
Af er releasing BEAM FINDER, adjus INTENSI
TY, FOCUS, VOLTS/DIV swi ch, horizon al, and
ver ical POSITION con rols for a viewable s able
display.
(? ) TRACE ROTation
Recessed screwdriver adjus men aligns cr race
wi h horizon al gra icule lines.
REV A MAY 1980 2-3

Operating Instructions—442 Service
(? ) ON indicator (LED)
Ligh s when power is applied o he 442 and he
POWER ON/OFF bu on is pressed in.
POWER INPUT SELECTOR SWITCHES and DC
BALANCE CONTROLS
(Bo om of Cabine . See Figure 2-6.)
© ON/OFF Push Button Switch
Turns ins rumen ON (in) and OFF (ou ).
Internal Graticule
Elimina es parallax. Rise ime ampli ude and
measuremen poin s are marked on he lef edge
of he gra icule. VOLTS/DIV and SEC/DIV se 
ings are calibra ed o he gra icule scale
divisions.
© PROBE ADJust
Pin connec or supplies in ernally genera ed
square wave of approxima ely 0.5 V a ap
proxima ely 1 kHz for use in checking a enua
ion fac ors and compensa ion of probes.
Z AXIS INPUT
(Rear Panel. See Figure 2-5.)
|0j External Z AXIS INPUT Connector
Bnc connec or accep s signals from ex ernal
sources for modula ing in ensi y of cr display.
Signals mus be ime-rela ed o he display for
s abili y. Posi ive signals decrease in ensi y. In
pu specifica ion a connec or is 30 V peak max
imum inpu and 10,000 £1 inpu impedance.
Figure 2-5. External Z AXIS INPUT connector on the ack pane!
of the 442.
CAUTION
Before operating or changing settings of Power
Input Selector switches, verify that the 442 power
cord is unplugged from the power source and that
the correct value of fuse is installed for the available
power input voltage (see Table 2-3, and Figures 2-3
and 2-6).
@ 120 V/240 V (Ac Power Input Selector Switch)
Two-posi ion, screwdriver ac ua ed slide swi ch,
which can be se o allow opera ion from an ac
source of ei her 120 V or 240 V. Posi ions are
marked on he cabine .
\2) HI/LO (Regulating Range Selector Switch)
Two-posi ion, screwdriver ac ua ed slide swi ch
which can be se o allow opera ion from one of
wo ac ranges (see Table 2-2). Posi ions are
marked on he cabine .
J3) CH 1 DC BAL (Channel 1 Dc Balance Control)
Screwdriver adjus men ( hrough cabine ). When
properly adjus ed, preven s race shif when
swi ching be ween adjacen posi ions of channel
1 VOLTS/DIV swi ch.
|4) CH 2 DC BAL (Channel 2 Dc Balance Control)
Screwdriver adjus men ( hrough cabine ). When
properly adjus ed, preven s race shif when
swi ching be ween adjacen posi ions of channel
2 VOLTS/DIV swi ch.
Vertical
(Fron Panel. See Figure 2-7.)
)5) CH 1 (X) (Channel 1 or X-axis Input)
Ac iva ed when he VERT MODE CH 1 bu on is
pressed in. Bnc connec or for he applica ion of
ex ernal signals o he channel 1 ver ical deflec
ion sys em. For X-Y opera ion, his connec or is
he horizon alJX-axis) signal inpu (see No e).
2-4 REV A MAY 1980

Operating Instructions—442 Service
NOTE
Channel 1 (X) is the horizontal (X-axis) signal input
and Channel 2 (Y) is the vertical (Y-axis) signal input
when the 442 is set for X-Y operation. The
T IGGE ING SOU CE switch must be set to X-Y
and the VE T MODE CH 2 button must be pressed in
for X-Y operation. The horizontal POSITION control
determines the X-axis signal display position and the
channel 2 POSITION control determines the Y-axis
signal display position when operating in the X-Y
mode.
n(f) VAR (Varia le volts/divislon controls for Channel
1 and Channel 2)
When ro a ed ou of he calibra ed (fully
clockwise de en ) posi ion, hese con rols
provide con inuously variable (uncalibra ed)
deflec ion fac ors be ween he calibra ed
posi ions of he VOLTS/DIV swi ches. Ex ends
maximum deflec ion fac ors o 25 V/div wi h
VOLTS/DIV swi ches se o 10 (vol ) posi ion and
VAR ro a ed fully coun erclockwise. VAR con
rols mus be se o he de en posi ion for
calibra ed deflec ion fac ors.
NT) CH 2 (Y) (Channel 2 or Y-axis input)
Ac iva ed when he VERT MODE CH 2 bu on is
pressed in. Bnc connec or for he applica ion of
ex ernal signals o he channel 2 ver ical deflec
ion sys em (see No e for X-Y opera ion).
(l?) AC-GND-DC (Input coupling switches tor
Channel 1 and Channel 2)
Three-posi ion lever swi ches ha selec he
me hod of in ernally coupling he ver ical inpu
signals o he ver ical amplifier inpu .
Yf) VOLTS/DIV (Channel 1 and Channel 2)
Swi ches ha selec he ver ical def I ec i on fac ors
in a 1-2-5 sequence. The i em 18 VAR con rols
mus be in he calibra ed (de en ) posi ion o
ob ain he deflec ion fac ors indica ed by he
swi ch se ings. The correc deflec ion fac or
when using a IX probe or cable is read from he
IX (lef ) knob skir window posi ion, and he
correc deflec ion fac or when using a 10X probe
is read from he 10X (righ ) knob skir window
posi ion.
AC: Signals are coupled capaci ively. Any dc
signal componen is blocked. Low fre
quencies are a enua ed (3 dB down a
abou 1 Hz using a 10X probe). Ac
coupling causes il ing of square waves
below 1 kHz.
GND: Grounds he inpu of he ver ical
amplifier o provide a ground reference
display. Connec s he applied signal o
ground hrough he inpu coupling
capaci or and a 1 MQ resis or o allow
he inpu coupling capaci or o be
precharged by he inpu signal.
DC: All frequency componen s of he inpu
signal are passed o he ver ical
amplifier.
Figure 2-6. Controls and switches accessi le through the
ottom of the 442 ca inet. Figure 2-7. Vertical system controls.
REV A MAY 1980 2-5