Tektronix 442 User manual

Ttektronix
COMMITTED TO EXCELLENCE
INSTRUCTION MANUAL

BEFORE READING— THIS MANUAL REPRINTED JULY 1980
PLEASE CHECK FOR CHANGE INFORMATION
AT THE REAR OF THIS MANUAL

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Tektronix, Inc.
.O. Box 500
Beaverton, Oregon 97077
070-2373-00

TEKTRONIX®
442
OSCILLOSCOPE
O ERATQRS
INSTRUCTION MANUAL
Serial Number ___________________ First rinting AUG 1977

W A R R A NTY
Tektroni warrants that this product is free from defects in materials and workmanship. The
warranty period is one (1) year from the date of shipment. Tektroni will, at its option, repair or
replace the product if Tektroni determines it is defective within the warranty period and if it is
returned, freight prepaid, to a service center designated by Tektroni .
Tektroni is not obligated to furnish service under this warranty:
a. to repair damage resulting from attempts by personnel other than Tektroni
representatives to install, repair, or service the product;
b. to repair damage resulting from improper use or from connecting the product to
incompatible equipment;
c. if personnel other than Tektroni representatives modify the hardware or software.
There is no implied warranty of fitness for a particular purpose. Tektronix is not liable for
consequential damages.
Copyright © 1977 Tektroni , Inc. All rights reserved. Contents of this publication
may not be reproduced in any form without the written permission of Tektroni , Inc.
Products of Tektroni , Inc. and its subsidiaries are covered by U.S. and foreign
patents and/or pending patents.
TEKTRONIX, TEK, SCOPE-MOBILE, and ^ 5 are registered trademarks of
Tektroni , Inc. TELEQUIPMENT is a registered trademark of Tektroni U.K.
Limited.
Printed in U.S.A. Specification and price change privileges are reserved.

TABLE OF CONTENTS
age
LIST OF ILLUSTRATIONS....................................................iii
LIST OF TABLES.......................................................................iii
BEFORE O ERATION
Introduction..............................................................................1
Safety Inform ation................................................................1
Operating Voltage...................................................................1
ower Operation ................................................................ 1
Fuse Inform ation.............................................................3
LOCATION AND O ERATION OF EXTERNAL
CONTROLS, CONNECTORS, AND INDICATORS
Introduction ............................................................................. 4
Crt Display and ower .......................................................... 4
External Blanking .................................................................. 6
ower Selectors and Dc Balance..........................................6
age
LOCATION AND O ERATION OF EXTERNAL
CONTROLS, CONNECTORS, AND INDICATORS (cont)
Vertical......................................................................................7
Horizontal..............................................................................10
Triggering.............................................................................. 11
BASIC OSCILLOSCO E O ERATION
reliminary ........................................................................... 14
Signal Ground ................................................................... 14
Input Coupling Capacitor recharging........................14
Operators Adjustments and Checks .................................. 15
robe Compensation......................................................15
Vertical Gain Check ........................................................ 15
Basic Timing Check ........................................................ 15
Normal Sweep Operation...................................................16
Applications ........................................................................... 17
edk-to- eak Voltage Measurements .......................... 17
Instantaneous Voltage Measurements—D c ............... 19
442 Operators I

TABLE OF CONTENTS (Cont.)
age
BASIC OSCILLOSCO E O ERATION
Comparison Measurements .......................................... 20
Time Duration Measurements.....................................23
Frequency Measurement................................................24
Rise Time Measurements................................................25
Time Difference Measurements .................................. 27
Multi-Trace hase Difference Measurements ............ 28
X-Y hase Measurement................................................30
ll 442 Operators @

LIST OF ILLUSTRATIONS
Fig. No. a9e
1 442 Oscilloscope...........................................................iv
2 Power switches on b o ttom ..........................................2
3 Line fuse location on Rear Panel................................3
4 CRT DISPLAY and POWER front panel
controls and indicators...............................................4
5 E ternal Z-AXIS input on Rear Panel........................6
6 Controls through bottom of cabinet .......................... 7
7 Vertical system controls...............................................9
8 Horizontal system controls ........................................ 10
9 Triggering system controls .......................................... 11
Fig. No. Page
10 Probe compensation.....................................................15
11 Display of 0.5 PROBE ADJ output signal .................. 17
12 Measuring peak-to-peak voltage of a waveform . . .18
13 Measuring instantaneous dc voltage with respect
to a reference voltage................................................19
14 Measuring the time duration between points
on a waveform ......................................................... 24
15 Measuring rise tim e .................................................... 26
16 Measuring time difference between two pulses . . . 28
17 Measuring phase difference........................................29
18 Phase difference measurement from an
X-Y display .............................................................. 30
LIST OF TABLES
Table No. Page
1Ac Regulating Ranges
......................... ....................... 2
2 Ac Fusing ...........................................
......................... 3
3Rise Time Measurements
.................... .......................25
@ 442 Operators iii

Fig. 1. 442 Oscilloscope
442 Operators

BEFORE O ERATING
INTRODUCTION
The Tektronix 442 Oscilloscope is a 35 MHz maximum
bandwidth instrument with dual trace capability. A dual
trace dc to 35 megahertz vertical system provides calibrated
deflection factors from 2 millivolts/division to 10 volts/
division. Trigger circuits provide stable triggering over the
full vertical bandwidth. A horizontal deflection system pro
vides calibrated sweep rates from 0.5 second/division to
0.1 microsecond/division. An X10 magnifier circuit (push
button switch) extends maximum sweep to 10 nanoseconds/
division. In X-Y mode of operation, vertical and horizontal
deflection factors are the same as vertical amplifiers.
SAFETY INFORMATION
The 442 Oscilloscope is designed to be operated from a
single phase power source which has one of its current car
rying conductors at ground potential (earth ground).
Operation from other power sources where both current
carrying conductors are live with respect to ground (such
as phase-to-phase, a multi-phase system, or across the legs
of a 117-234 V single-phase three-wire system) is not re
commended because only the Line Conductor has over
current (fuse) protection within the instrument.
Each instrument is provided with a three-wire power
cord with a three-terminal, polarized plug for connection
to power source. The grounding terminal of the recep
tacle is directly connected to the instrument chassis and
cabinet as recommended by national and international
safety codes. Color coding of cord conductors follows the
I.E.C. which specifies: Line, brown; Neutral, blue; Safety
Earth or Ground, green with a yellow stripe (or solid
green).
O ERATING VOLTAGE
ower Operation
The 442 operates from either 120 V or 240 V ac input —
at 48 to 62 Hz. Selection of input function is made with
screwdriver adjusted switches accessible through bottom
of cabinet (see Fig. 2). Adjustment for high or low power
input can be made with same tool at same cabinet position.
@442 Operators 1

WARMING
Do not plug instrument into power source until
the following settings are made or checked.
Set the Line Voltage Selector switch to the nominal line
voltage available (see Fig. 2).
Set the Regulating Range Selector Switch (see Fig. 2)
so expected line-voltage fluctuations remain within the
Regulating Range selected (see Table 1).
Table 1
Ac Regulating Ranges
Regulating Regulating Range
Range Selector 120 V 240 V
Switch osition Nominal Nominal
HI 108 to 132 V RMS 216 to 250 V RMS
LO 90 to 110 V RMS 198 to 242 V RMS Fig. 2. ower switches at bottom.
2442 Operators @

Fuse Information
The 442 contains a power fuse located in a fuseholder
on the Rear anel (see Table 2 and Fig. 3). WARNING
Dangerous potentials e ist at several points
throughout this instrument. Qualified person
nel, only, are authorized to remove cabinet.
Table 2
Ac Fusing
Fused Line F700
120 Vac 0.75 A Fast Blow
240 V ac 0.30 A Slow Blow
Fig. 3. Line fuse location on Rear anel.
@442 Operators 3

LOCATION AND O ERATION OF EXTERNAL
CONTROLS, CONNECTORS AND INDICATORS
INTRODUCTION
The following information will familiarize an operator
with location and operation of e ternal controls, con
nectors and indicators. These controls, connectors, and
indicators are accessible from outside the instrument with
its cabinet in place. All other controls are internal and
should not be adjusted e cept during instrument cali
bration and service. Procedures and suggestions for cali
bration and maintenance are presented in the 442 Service
Manual.
CRT DIS LAY AND OWER
(Front anel. See Fig. 4)
@ ASTIGmatism
Recessed screwdriver control adjusts crt writing beam
for optimum definition.
( ? ) INTENSITY
Turn control clockwise to increase display brightness.
Set for lowest visible display to prolong crt life.
Fig. 4. CRT DIS LAY and OWER front panel controls and
indicators.
4442 Operators @

® F O C U S
rovides optimum display definition.
After releasing BEAM FINDER, adjust VOLTS/DIV
switch, horizontal, and vertical OSITION controls
for a readable, stable display.
( T ) BEAM FINDER
Spring-loaded push-button switch to locate off
screen displays. When engaged crt display is electrically
compressed to within graticule area independently
of position controls or applied signals. To locate an
off-screen display:
a. Set vertical OSITION and INTENSITY controls
to midrange and rotate horizontal OSITION control
clockwise.
b. If a display or dot still is not visible, press BEAM
FINDER and hold in. A compressed display or dot
should appear. If not, increase INTENSITY until a
display appears.
If a dot or vertical line appears, the sweep is not trig
gered. Set trigger MODE switch to AUTO and obtain
a display. Center the display with vertical and hori
zontal OSITION controls. Release BEAM FINDER
push button and adjust trigger LEVEL control for a
stable display.
® TRACE ROTation
Recessed screwdriver adjustment aligns crt trace with
horizontal graticule line.
(J )O N Indicator (LED)
Lights when the power is on.
^ ^ O N —OFF ush Button Switch
Turns instrument on (in) and off (out).
Internal Graticule
Eliminates parallax. Risetime, amplitude and
measurement points are indicated at the left of
graticule.
® ROBE ADJust
in connector supplies internally generated square
wave of approximately 0.5 volts at approximately
1 kHz for use in checking attenuation factors and
compensation of probes.
442 Operators 5

EXTERNAL BLANKING OWER SELECTORS AND DC BALANCE
(Rear anel. See Fig. 5) (Bottom of Cabinet. See Fig. 6)
(jO) External Z-AXIS IN UT
BNC connector accepts signals from external sources
for modulating intensity of crt display. Signals must
be time-related to the display for stability. ositive
signals decrease intensity. Input specification at con
nector is 30 V peak with 10,000 ohms impedence.
CAUTION
Make sure instrument is unplugged from power
source and appropriate fuse is installed in fuse
holder at rear of instrument—considering ac
power input (see Table 2).
2373-5
Line Voltage Selector
Two-position, screwdriver actuated, slide switch which
can be set to allow operation from an ac source of
either 120 V or 240 V. osition left for 120 V ac and
position right for 240 V ac.
^ 2 ) Regulating Range Selector
Two-position, screwdriver actuated, slide switch
which can be set to allow operation from one of two
ac ranges (see Table 1). osition left for HI and posi
tion right for LO.
6442 Operators @
Fig. 5. External Z-AXIS IN UT on Rear anel.

(IT) Channel 1 DC Balance
Screwdriver adjustment (through cabinet). When pro
perly adjusted, prevents trace shift when switching
between adjacent positions of channel 1 VOLTS/
DIV switch.
(m) Channel 2 DC Balance
Screwdriver adjustment (through cabinet). When
properly adjusted, prevents trace shift when switching
between adjacent positions of channel 2 VOLTS/
DIV switch.
VERTICAL
(Front anel. See Fig. 7)
@
(TT) Channel 1 (X) Input
Fig. 6. Controls through bottom of cabinet.
BNC connector for the application of e ternal signal
to channel 1 vertical deflection system. In X-Y oper
ation, channel 1 or X is horizontal input. Display mode
is selected by VERT MODE switches.
442 Operators 7

NOTE brated deflection factors. Extends maximum deflection
factor to 25 V/div in 10 V position. (Notice that VAR
decreases size of display.)
Channel 1 (X ) is horizontal input and Channel
2 (Y) is vertical in put when instrument is used
in SOURCE X-YS
^ 6 ) Channel 2 (Y) Input
BNC connector for the application of external signal
to channel 2 vertical deflection system. In X-Y oper
ation, channel 2 or Y is vertical input. Display mode
is selected by VERT MODE switches.
(l7 ) VOLTS/DIV (Both Channels)
Controls which select the vertical deflection factors
in 1-2-5 sequence. (VAR control must be in detent
position to obtain the indicated deflection factors.)
Read the correct deflection factor for a IX probe
from the 1X (left) position; and for a 10X probe
from the 10X position (right).
(T9)VARiable (Both Channels)
Controls—out of detent left—which provide contin
uously variable (uncalibrated) deflection factors be
tween calibrated positions of the VOLTS/DIV switches.
Rotate controls clockwise to detent position for cali-
)9 j Input Coupling AC-GND-DC (Both Channels)
Three-position slide switch which selects the circuit
method of coupling input signals to vertical input
amplifier.
AC: Signals are coupled capacitively. Any dc
signal component is blocked. Low frequencies are
attentuated (3 dB down at about 1 Hz using a 10X
probe). Ac coupling causes tilting of square waves
below 1 kHz.
GND: Disconnects input of vertical amplifier
from the input signal and connects amplifier input
to ground to provide a ground reference display.
Connects input signal to ground through input
coupling capacitor and a 1 MJ2 resistor to allow in
put coupling capacitor to be precharged by input
signal.
DC: All frequency components of input signal
are passed to vertical amplifier.
8442 Operators @

(20) t OSITION (Both Channels)
Controls which position the related channel signal
displays in a vertical position.
^ j ) External Ground Connector
Banana plug connected directly to chassis and cabinet
provides instrument ground.
VERT MODE (Vertical Display Mode)
Series of five in line push-button switches to select
vertical channel display and operating mode. (Trig
gering signals are derived from channel 1 input ex
cept when CH 2 and one of DIFF, ALT, or CHO
switches are engaged simultaneously.)
CH 1: Displays only signals applied to Channel
1 input connector.
DIFF: rovides a display of the algebraic dif
ference between Channel 1 and Channel 2 input
signals. Trigger signal is derived from Channel 1 un
less CH 2 and DIFF push-buttons are depressed
simultaneously.
ALT: rovides a display of Channel 1 and
Channel 2 alternately. Display is switched between
channels at the end of each sweep. Trigger signal is
automatically derived from Channel 1 input signal
unless CH 2 and ALT push buttons are depressed
simultaneously.
CHO : rovides a display of signals from both
channels switched from Channel 1 to Channel 2 at
a frequency of approximately 250 kHz. Trigger
signal is automatically derived from Channel 1 input
signal unless CH 2 and CHO push buttons are de
pressed simultaneously.
@442 Operators 9

OSITION
CH 2: Displays only signals applied to the Channel
2 input connector. CH 2 push-button must be en
gaged for X-Y operation.
HORIZONTAL
(Front anel. See Fig. 8)
(23) SEC/DIV
Control selects calibrated sweep rates from 0.5
seconds/division to 0.1 microseconds/division in a
1-2-5 sequence.
@ V A R
Control, inside SEC/DI V control, provides contin
uously variable uncalibrated sweep rates to at least
2.5 times the calibrated setting (extends the slowest
sweep rate to at least 1.25 sec/div).
(25) MAGNIFIER X 10-X1
ush-button switch (in, X I0) increases each sweep
rate by a factor of 10. Extends the fastest sweep rate
to 10 nanoseconds/division.
Control to horizontally position the crtdisplay.
10 @
442 Operators