Tektronix 2445 User manual

Tektronix, Inc.
P.O.
Box 500
Beaverton. Oregon 97077
070-3830-00
Product Group 38
COMMITTEDm EXCELlENCE
PLEASE CHECK FOR CHANGE INFORMATION
AT THE REAR OF THIS MANUAL
2445
OSCILLOSCOPE
OPERATORS
INSTRUCTION MANUAL
Serial Number _____ _
First Printing OCT 1982
Revised
JUL 1983

Copyright ® 1982 Tektronix. Inc. All rights reserved.
Contents
of this publication may not be reproduced in any
form without the written permission of Tektronix.
Inc.
Products of Tektronix, Inc. and its subsidiaries are covered
by U.S. and foreign patents andlor pending patents.
TEKTRONIX, TEK, SCOPE-MOBILE, and it are
registered trademarks
of Tektronix. Inc. TELEQUIPMENT
is a registered trademark of Tektronix U.K. Limited.
Printed
in U.S.A. Specification and price change privileges
are reserved.
INSTRUMENT SERIAL NUMBERS
Each instrument has a serial number on a panel insert, tag,
or stamped
on the chassis. The first number or letter
designates the country of manufacture.
The last five digits
of the serial number are aSSigned sequentially and are
unique to each instrument. Those manufactured
in the
United States have six unique digits. The country of
manufacture
is identified as follows:
BOOOOOO Tektronix, Inc .• Beaverton, Oregon, USA
100000 Tektronix Guernsey, Ltd., Channel Islands
200000 Tektronix United Kingdom. Ltd., London
300000 SonyITektronix, Japan
700000 Tektronix Holland, NV, Heerenveen,
The Netherlands

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2445 Operaton
tABLE OF CONTENTS
Page
LIST OF ILLUSTRATIONS. . • . • . . . • . • • • . • . • ji
LISTOF TABLES. . • . . • . . • • • . • . • . • • • . • • • • ii
OPERATORS SAFETY SUMMARY. • • • . • • . • . • • iii
SECTION 1 SPECIFICATION
INTRODUCTIQN. . • • . • • • • • •
•• 1·1
PERFORMAN¢E CONDITIONS. •• 1·1
SECTION 2 PREPARATION FOR USE
SAFETY ....•.••.••.••.• , •• 2·1
LINE VOLTAGE SELECTION. • •• 2·'
LINE FUSE. . • . • • . . • • . . • • . .• 2·1
POWER CORD.. . .• . • •• . . •• •• 2·'
INSTRUMENT COOLING. . • • • •• 2·1
START·UP. . . . • • • • . • • • • • • . .. 2·2
REPACKAGING FOR SHIPMENT.. 2·2
SECTION 3 CONTROLS, COII'NECTORS.
AND INDICATORS
POWER AND DISPLAY. . . . . • . •• 3·1
VERTICAL. • . . • • • . • • . • • . • •• 3·2
HORIZONTAl-AND DELTA
MEASUREMENT. • •• • • • • •.. • •• 3-4
TRIGGER. . • . • • • • • • • • . . . •
•• 3-7
REAR PANEL. • • . . •• .•• • •• .• 3-9
READOUT DISPLAY
••.••••.•. 3·11
SECTION 4 OPERATING cqNSIDERATIONS
GRATICULE
:. . • • • • • • • • . • • • .• 4·1
TIME AND V~LTAGE
MEASUREM~NTS .••.••.•.. " 4-1
GROUNDING. . • • • • . • • • • • • •• 4·1
SIGNAL CO~ECTIONS. • • • • • •• 4·2
INPUT·COupLING CAPACITOR
PRECHARGI"'G. • •
•• . . • . . . • •• 4·2
EXTERNAL tRIGGERING. • • • .• 4·2
SECTION 5 OPERATOR·S
CHECKS AND
ADJUSTMENTS
INTRODUCTION.
•• • . . . • •. • .• 5·1
INITIAL SETUP. . • • • • . • . • • • .• 5·1
TRACE ROTATION
ADJUSTMENT
••.•.••.....•.• &1
ASTIGMATISM ADJUSTMENT •
•. &2
AUTO DC BALANCE
ADJUSTMENT. • • • • • . . • . . . • .. &2
PROBE LOW·FREQUENCY
COMPENSATION. . • . . • • • • • •
•• &2
MATCHING CHANNEL2 DELAY.. 5·3
AMPLITUDE CHECK • • . • . . • •
•. 5-4
TIMING CHECK. • • . • • • . . • • •
.• 5-4
SECTION 6 BASIC APPLICATIONS
INDEXOF PROCEDURES. • • • •
.• 6·1
VOLTAGE MEASUREMENT. • • .. 6·1
VOLTAGE RATIO. • . • • . . • • • •• 6-2
ALGEBRAIC ADDITION AND
ELiMINATINGCOMMON·MODE
SIGNALS • • • • . • • . • . . • . . . •
•• 6·3
TIME
INTERVAL.. • •• . . • • . . •. 6-4
FREQUENCY • . . . • • • . . • • • • •• 6-4
TIME DIFFERENCE BETWEEN
TWO TIME·RELATED PULSES. •• 6·5
TIME RATIO
••••.•••.• " . • •• 6-5
PHASE DIFFERENCE BETWEEN
TWO TIME·RELATED SIGNALS •. 6-6
SMALL·ANGLE
PHASE
DIFFERENCE. . • . . . • . . • • • • •• 6-6
DELAYED·SWEEP OPERATION
.• , 6-7
SECTION 7 OPTIONS AND ACCESSORIES
INTRODUCTION.. • . . . . • • • • .• 7·1
OPTION lR. . • . . • • . • • • • • • • .• 7·1
POWER CORD OPTIONS. • . . • • .. 7·1
STANDARD ACCESSORIES ..•• , 7·2
OPTIONAL ACCESSORIES. • • .
.• 7·2
APPENDIX A
POWER·UP TESTS
KERNELTESTS ••••.•••..••. , A·'
CONFIDENCE TESTS. . • • . • • . .. A·1
CHANGE INFORMATION

2445 Operators
LIST OF ILLUSTRATIONS
Figure Page
The 2445 Oscilloscope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv
2·1 Line selector switch, line fuse, and detachable power cord. . . . . . . . . . . . . . . . . . . . . . .. 2·2
3-1 Power and display controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3·1
3-2 Vertical controls and CH 1 OR X and CH 2 connectors. . . . . . . . . . . . . . . . . . . . . . . . .. 3-2
3-3 Channel 3 and Channel 4 controls and connectors and CALIBRATOR output ......... , 3-3
3-4 Horizontal and delta measurement controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-4
3·5 Trigger controls and indicators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . • . .. 3-7
3-6 Rear-panel controls and connectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3·'0
3·7 Readout display locations ...............................•............ , 3·11
4-1 Graticule measurement markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4-1
5-1 Probe low·frequency compensation. . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-3
6-1 Instantaneous dc levels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . .. 6-1
6-2 Voltage ratios. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-2
6-3 Eliminating common-mode signals • . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . .
.. 6-3
6-4 Measuring rise times. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-4
6-5 Time difference between two time-related pulses (cursor method) ................. , 6-5
6-6 Time ratios (duty cycles) . . . . . . . . . . . • . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-6
6·7 Phase difference between two time-related signals. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-7
6·8 Small-angle phase difference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-7
6-9 Time difference between two time·related pulses (delayed-sweep method) . . . . . . . . . . . .. 6-9
LIST OF TABLES
Table Page
1-1 Electrical Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-2
1-2 Environmental Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-9
1-3 Mechanical Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-10
2·1 Voltage, Fuse, and Power-Cord Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2-3
A·1 Confidence Test Numbers and Descriptions ................................ , A-'
ii

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2445 Operators
OP~RATORS SAFETY SUMMARY
The general safety information ~ this part of the summary is for both operating andservicing personnel Specific warnings
andcautions will be found thrtWphout the manual where theyapplyanddo not appear in thissummary.
Terms in This Manual
CAUTION statements identity conditions or practices
that could result
in damage ~ the equipment or other
property.
WARNING statements identiiv conditions or practices
that could result
in personal inlfry or loss of life.
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Terms as Marked on Equi~
CAUTION indicates a person~ injury hazard not imme-
diately accessible as one reads' the markings, or a hazard to
I
property, including the equipm,mt itself.
DANGE R indicates a personal injury hazard immediately
accessible
as one reads the rnar~ing.
Symbols in This Manual
This symbol i~dicates where applicable
cautionary or other information
is to be
found. For
maPcimum input Voltage see
Table 1-1. I
Symbols as Marked on E~ipment
DANGER -Hitti voltage.
1
Protective grou~ (earth) terminal.
ATTENT ION - ~efer to manual.
Power Source
This product is intended to ~perate from a power source
that does not apply more
th" 250 volts rms between the
supply conductors or betweel'l either supply conductor and
ground. A protective
groun~ connection by way of the
grounding conductor
in the pt:>wer cord is essential for safe
operation. '
Grounding the Product
This product is grounded through the grounding conductor
of the power cord. To avoid el~trical shock, plug the
power cord into a properly wired receptable before con-
necting to the product input or output terminals. A
protective ground connection
by way of the grounding
conductor
in the power cord is essential for safe operation.
Danger Arising From Loss of Ground
Upon loss of the protective.ground connection, all acces-
sible conductive parts (including knobs and controls that
may 8PPear to be insulating) can render an electric shock.
Use the Proper Power Cord
Use only the power cord and connector specified for
your product.
Use only a power cord that is in good condition.
For'detailed information on power cords and connectors
see Table 2·1.
Use the Proper Fuse
To avoid fire hazard, use only a fuse of the correct type,
voltage rating and current rating as specified in the parts
list for your product.
Do Not Operate in Explosive Atmospheres
To avoid explosion, do not operate this product in an
explosive atmosphere unless it has been specifically cer-
tified for such operation.
Do Not Remove Covers or Panels
To avoid personal injury, do not remove the product
covers or panels.
Do not operate the product without the
covers and panels properly installed.
iii

2445 Operators
-
.....,
3830-01
The 2446 OscillolCOpe.
iv

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Section 1-2445 OperatO"
SPECIFICATION
INTROD..,cnON
The TEKTRONIX 2445 Oscilloscope is a portable
150-MHz instrument having a Ifour-channel vertical deflec-
tion system. Channel 1 and Channel 2 provide calibrated
deflection factors from 2 mV per division to 5 V per
division. For each of these channels, input
impedanCe is
selectable between two val~: either 1 MSl in parallel
with 15 pF, or 50 Sl internelf termination. Input-signal
coupling with 1-MSl impedanf:e can be selected as either
AC or DC. Channel 3 and Chaqnel 4 have deflection factors
of either
0.1 V or 0.5 V per dlvjision. Each of these channels
has
an input impedance of 1 !MSl in parallel with 15 pF,
with
DC input-signal coupling.!Trigger circuits enable stable
triggering over the full bandwkfth of the vertical system.
The horizontal deflection! system provides calibrated
I '
sweep speeds from 1.5s per aiviston to 1 ns per division.
Drive for the horizontal deflechion system is obtained from
a choice
of A, B delayed, Aalternated with B delayed
sweeps, or
CH 1 (for the X·Y ~sptay mode).
The 2445 incorporates
alp~anumeric crt readouts of the
vertical and horizontal
scat~ factors, the trigger levels,
time-difference measurem~ values, voltage-difference
me.asurernent values, and certa~ auxiliary information.
The 2445 Oscilloscope
isl shipped with the following
standard accessories:
2 Probe packages
1 Snap-lock accessories pouch
1 Zip-lock accessories
pou~h
1 Operators manual
1 .Service manual
1 Power cord (installed)
1 2·A, 250-V fuse
1 Clear plflstic
crt filter I
1 Blue plastic crt filter (inualled)
1 Front-panel cover
1 Operators pocket
referer card
For part numbers and further information about both
standard and optional accessories, refer to "Options and
Accessories" (Section 7) of this manual. Your Tektronix
representative or
local Tektronix Field Office can also
provide accessories information and ordering assistance.
PERFORMANCE CONDITIONS
The following electrical characteristics (Table 1-1)
are
valid for the 2445 when it has been adjusted at an
ambient temperature between +20°C and +30°C, has had
a warm-up period of
at least 20 minutes, and is operating
at an ambient temperature between _15
0 C and +55°C
(unless otherwise noted).
Items listed in the "Performance Requirements" column
are verifiable qualitative or quantitative limits that define
the measurement capabilities
of the instrument.
Environmental characteristics are
given in Table '-2.
The 2445 OscilloscOpe meets the environmental require-
ments of MIL·T-28BOOC for Type III, Class 3, Style C
equipment, with the humidity and temperature require-
ments defined in paragraphs 3.9.2.2, 3.9.2.3, and 3.9.2.4.
Mechanical characteristics of the 2445 are listed in
Table 1-3.
1-1

Specification-2445 Operators
Characteristics
Table 1·'
Electrical Characteristics
Performance Requirements
VERTICAL DEFLECTION
SYSTEM-CHANNEll AND CHANNEL 2
Deflection Factor
Range
Accuracy
+15°C to +35°C
Ll. V Accuracy (using cursors over entire
graticule area)
+15°Cto +35°C
Ll.V Range
Variable Range
Frequency Response
{3·dB bandwidth)
AC Coupled Lower -3 dB Point
1X Probe
lOX Probe
Step Response
Rise Time
Common-mode Rejection Ratio (CMRR)
1-2
2 mV per division to 5 V per division in a 1-2·5 sequence of 11 steps.
Within ±2%
at any VOLTS!D IV setting for a 4- or 5·division signal
centered
on the screen.
Add
1% to +lSoC-to-+35°C specification.
± (2%
of reading + 0.03 division + signal aberrations).
1% of reading to +150 C-to·+35°C specification.
± 8 times the VOLTS/DIV switch setting.
Continuously variable between VOLTS!DIV switch settings. Extends
deflection
factor of the 5 V per division setting to at least 12.5 V
per division.
Six-division reference signal from a terminated 50·51 system, with
VAR VOLTS!DIV control in calibrated
detent.
VOLTS/DIV
setting
2mV
5 mV or greater
5 mV or greater
Hz or less.
With
probe or internal
50-51
termination
DCto 150 MHz
DC to 100 MHz
50-n external
termination on
1-M51 input
DC to 80 MHz
OCto 130 MHz
DC to 100 MHz
2.33 ns or less for VOLTS/O IV switch settings of 5 mV and up
(calculated).
4.4 ns or less for VOLTS/OIV switch setting of 2 mV {calculated).
Rise
time calculated from: bandwidth x rise time = 0.35.
At least 20: 1 at 50 MHz for common-mode signals of eight divisions
or less, with VAR VOLTS/DIV control adjusted for best CMRR at
50 kHz at any VOLTS/OIV switch setting from 5 mV to 5 V; at
least 20:1 at 20 MHz at 2 mV per division.

Specification-2445 Operators
Table 1-1 (cont)
Characteristic$ Performance Requirements
VERTICAL DEFLECTION SYSTEM-CHANNEL 1 AND CHANNEL 2 (cont)
Channel Isolation 100:1
or greater attenuation of the deselected channel at 100 MHz;
50:1 or greater attenuation at 150 MHz, for an eight-division input
signal from 2 mV per division
to 500 mV per division, with equal
switch settings on both channels.
Displayed Channel 2 Signal Delay with Respect Adil",bhl
... through a range of at teast -500 ps to +500 ps.
to Channel 1 Signal
Input
Rand C (1 MO}
Resistance Mn±O.5%.
Capacitance pF ±2 pF.
MaximulTllnput Voltage &
400 V (dc +peak ac).
: V pop ac
at 10kHz or less.
Input R {50 n}
Resistance
5On±i%.
VSWR (DC to 150 MHz)
.3:1 or less.
Maximum Input Voltage & 5 V rms;
50 mW·seconds during any loo-ms interval for
instantaneous voltage from 5 V to 50 V.
---,---.------.-~--.------.--~------"
------.----.-----~--~-,--,----.---- .. ------.--.---"---.--
Cascaded Operation
CH 2 SIGNAL OUT into Channel 1 input; DC coupled using a
50-n RG·58C/U coaxial cable, terminated in 50 n at the Channel 1
input. Channel 1 and Channel 2 VOLTS/DIV switch set
to 2 mV.
Bandwidth
to 50 MHt or greater.
Deflection Factor
400 J.tV per division ±10%.
VERTICAL DEFLECTION SYSTEM-CHANNEL3 AND CHANNEL4
.
Deflection Factor
Values V per division and 0.5 V per division.
Accuracy ±10%.
Frequency Response (3<1B Bandwidth)
c;. ."-
reference signal, from a terminated 5O-n system.
_.
With standard accessory probe With external
50-n termination
OCto 150 MHz
DC to 130 MHz
Step Response
Rise Time 2.33
ns or less (calculated from bandwidth).
Channel Isolation 50:1
or greater attenuation of the deselected channel at 100 MHz
with an eight-division input signal.
1-3

Specification-2445 Operators
Table 1-' (cont)
Characteristics Performance
VERTICAL DEFLECTION SYSTEM-CHANNEL 3 AND CHANNEL 4 (cant)
Input Rand C
Resistance
Capacitance
Maximum Input Voltage &
Mfl±l%.
5 pF ±3 pF.
V (dc +peak ac);
V Pop ac at 10 kHz or less.
VERTICAL DEFLECTION SYSTEM-ALL CHANNELS
Low-frequency Linearity
Bandwidth Limiter
Vertical Signal Delay
Chopped Mode Switching Rate
--------------
-----------------------
Minimum pop Signa! Amplitude for Stable
Triggering from Channell or Channel 2 Source
DC Coupled
NOISE REJ Coupled
ACCoupled
HF R EJ Coupled
IF REJ Coupled
-----------_._--------------
Minimum p.p Signal Amplitude for Stable Triggering
from Channel 3 or Channel 4 Source
-----------------------------.---
0_1 division or less compression or expansion of a two-division,
center-screen signal when positioned anywhere within the graticule
area.
Reduces upper 3·dB bandpass to a limit of 13 MHz to 24 MHz.
i At least 20 ns of the sweep is displayed before the triggering event
I is displayed.
---
Vertical display switches sequentially through the selected channels
at the chop switching rate. If the B_SEC/DIV switch is set to sweep
speeds outside the range of 20 p.s per division to 2 p.s per division,
the switching rate is 1 MHz ±0.2% (dual-channel cycle rate of
500 kHz). If the BSEC/DIV switch is set within the range of 20 p.s
per division to 2 f,J.S per division, the switching rate is 2.5 MHz ±0.2%
(dual·channel cycle rate of 1.25 MHz). At all sweep speeds, the
chop switching rate
is desynchronized with the sweep frequency to
minimize waveform breaks when viewing repetitive signals.
TRIGGERING
0.35 division from dc to 50 MHz, increasing to 1 division
at 250 MHz.
1.2 divisions or less from de to 50 MHz, increasing to 3 divisions
at 250 MHz.
0.35 division from 60 Hz to 50 MHz, increasing to 1 division at
250 MHz. Attenuates signals below 60 Hz.
0.35 division from dc to 30 kHz.
0.35 division from 80 kHz to 50 MHz, increasing to 1 division
at 250 MHz.
Amplitudes are one-half of Channel 1 or Channel 2 source
specification.
Minimum poP Signal Amplitude for Stable Triggering Add 1 division to single-channel source specifications.
from Composite, Multiple Channel Source in Al T
Vertical Mode
1-4