Tektronix 2245A User manual

OPERATORS
MANUAL
070-6558-01
Product Group 46
2245A
PORTABLE
OSCILLOSCOPE
OPERATORS
Please Check for
CHANGE INFORMATION
at the Rear of This Manual
First Printing JAN 1989
Revised JUN 1989
COMMITTED TO EXCELLENCE

Copyright © 1987,1889 Tektronix, inc. Ail rights reserved. Contents of this
publication may not be reproduced in any form without the written permis¬
sion of Tektronix, Inc.
Products of Tektronix, Inc. and Its subsidiaries are covered by U.S. and
foreign patents and/or pending patents.
TEKTRONIX, TEK, SCOPE-MOBILE and
of Tektronix, Inc.
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 manufac¬
ture. 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, U.S.A.
G100000 Tektronix Guernsey, Ltd., Channel Islands
E2000C0 Tektronix United Kingdom, Ltd., Marlow
J300000 Sony/Tektronix, Japan
H700000 Tektronix Holland, NV, Heerenveen, The Netherlands
HKOOOOO Tektronix, inc. Hong Kong
are registered trademarks

Power Source
This product is intended to operate from a power source that does not ap¬
ply more than 250 V rms between the supply conductors or between either
supply conductor and ground. A protective ground connection, by way of
the grounding conductor in the power cord. Is essential for safe operation,
Grounding the Product
This product is grounded through the grounding conductor of the power
cord. To avoid electrical shock, plug the power cord into a properly wired
receptacle before making any connections to the product input or output
terminals. A protective ground connection, by way of the grounding con¬
ductor in the power cord, is essential for safe operation.
Danger Arising From Loss of Ground
Upon ioss of the protective-ground connection, ail accessible conductive
parts, including knobs and controls that may appear to be insulating, can
render an electric shock.
Use the Proper Power Cord
Use only the power cord and connector specified for your product.
The power cord must be in good condition.
Read Section 1 for power-cord and connector information.
Use the Proper Fuse
To avoid fire hazard, use only a fuse of the correct type, voltage rating and
current rating as specified on the back of your product and in Table 6-1.
Do Not Operate in an Explosive Atmosphere
To avoid explosion, do not operate this product in an explosive atmosphere.
2245A Operators
ix

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.
x
2245A Operators

SECTION
NTRODUCTION
2245A Operators

Introduction
Description
The 2245A is a 100 MHz, four-channel, dual-sweep, portable oscilloscope
for general-purpose use (Figure 1-1). A microprocessor-based operating
system controls most of the functions in the instrument, including a voltage
and time cursor measurement system and a single-button automatic
front-panel setup feature. A menu-driven service mode provides for con¬
figuring of single-sweep readout displays, internal calibration, and servicing
diagnostics.
Figure 1-1. The 2245A Oscilloscope.
2245A Operators
1-1

Introduction
The vertical deflection system has four input channels. Two channels have
11 basic deflection factors from 2 mV to 5 V per division, and two channels
have two basic deflection factors of 0.1 V and 0.5 V per division. Basic
deflection factors can be extended with attenuator probes. VOLTS/DIV
readouts are switched to display the correct vertical scale factors when
properly coded probes are connected to the vertical input connectors.
The horizontal deflection system provides single, dual, or delayed sweeps
from 0.5 s to 20 ns per division {delayed sweep, 5 ms to 20 ns per division).
The trigger system provides stable triggering over the fui! bandwidth of the
vertical deflection system.
Alphanumeric crt readouts of the vertical and horizontal scale factors are
displayed at the bottom of the screen. On-screen vertical and horizontal
cursors provide accurate voltage, time, and frequency measurements;
measurement values are displayed at the top of the crt.
The measurement system provides direct readout of delta voltage, delta
time, and frequency from positionable cursors. Delay-time and delta-delay
measurements for time and frequency are available in ALT and B Horizontal
Modes.
By pressing a single button (AUTO SETUP), the front-panel controls can
be set up to produce a usable waveform display based on the voltage and
time characteristics of the input signals.
1-2
2245A Operators

Introduction
Standard Accessories
The following items are standard accessories shipped with the 2245A
instrument:
2 Probes, 10X, 1.5 meter, with accessories
1 Power cord
1 Power cord clamp
1 Operators manual
1 Reference guide
1 Crt filter, blue plastic (installed)
1 Fuse, 2A, 250 V. slow-blow
1 Accessory pouch, Ziploc
See Section 8 “Options and Accessories" for part numbers and further
information about standard accessories and a list of the recommended
optional accessories. For more information on accessories and ordering
assistance, contact your Tektronix representative or local Tektronix Fieid
Office.
2245A Operators
1-3

Introduction
PREPARATION FOR USE
Refer to the Operators Safety Summary at the front of this manual for
power source, grounding, and other safety information about the use of the
instrument. Before connecting the 2245A to a power source, read this
section and the Safety Summary.
Line Fuse
5 CAUTION |
t<vwwwv“
This instrument can be damaged if the
installed.
Verify the proper value of the power-input
procedure.
1. Press in the fuse-holder cap and release
clockwise rotation.
2. Pull the cap (with the attached fuse inside) out of the fuse holder.
3. Verify proper fuse value.
4. Install the proper fuse and reinstall the fuse-holder cap.
Line Voltage and Power Cord
The 2245A operates on line voltages from 90 to 250 V with line frequencies
ranging from 48 to 440 Hz. No line voltage selecting is necessary. Instru¬
ments are shipped with the power cord that was requested on the order.
The power cord must match the power-source outlet; if it does not, con¬
tact your Tektronix representative or local Tektronix Field Office. See
Figure 1-2 for optional power cords available.
The detachable three-wire power cord has a three-contact plug for con¬
nection to the power source and the protective ground. The power cord is
held to the rear panel by a clamp. The protective ground contact on the
plug connects (through the power cord protective-ground conductor) to
the accessible metal parts of the instrument.
wrong line fuse is
fuse with the following
it with a slight counter-
1-4
2245A Operators

Introduction
WARNING
For electrical-shock protection, insert this plug into a power-
source outlet that has a properly grounded protective-ground
contact.
Plug
Configuration Usage
Line
Voltage
Reference
Standards
Option
Number
North
American
120V/
15A
120V
ANSI C73.11
NEMA 5-15-P
IEC 83
■
Universal
Euro
240V/
1Q-16A
240V
CEE (7),11,1V,VII
IEC 83
A1
, A35\
UK
240V/
13A
240V
BS 1363
IEC 83
A2
Australian
240V/
10A
240V
AS Cl 12
A3
North
American
240V/
15A
240V
ANSI C73.20
NEMA 6-15-P
IEC 83
A4
Switzerland
220V/
6A
220V
SEV
A5
Abbreviations:
ANSI — American National Standards Institute
AS — Standards Association of Australia
BS — British Standards Institution
CEE — International Commission on Rules for the
Approval of Electrical Equipment
(EC — International Electrotechnical Commission
NEMA — National Electrical Manufacturer's Association
SEV — ■ Schweizevischer Elektrotechischer Verein
( 2931 - 21 ) 6558-02
Figure 1-2. Optional power cords.
2245A Operators
1-5

Introduction
Instrument Cooling
To prevent instrument damage from overheated components, make sure
the Internal airflow Is not blocked. Before turning on the power, check that
the ventilation holes on the bottom and side of the cabinet are not covered.
Start-Up
At power on, the instrument does a self-diagnostic check. If the instrument
does not turn on and operate normally, turn power off then on again. If the
instrument still does not turn on properly, refer the instrument to a qualified
service person. TRIGGER MODE LEDs may be flashing to indicate the
circuit location of a start-up error; you should report this information to the
service person.
When the instrument is turned on, a self-cal routine may run to set the
voltage- and timing-measurement constants. The power-on self cal runs
only if the stored constants have been lost, possibly due to a dead memory
back-up battery. The following warning message will be displayed for 5 sec¬
onds: -WARNING PROBABLE BATTERY FAILURE TURN OFF AND ON TO
VERIFY”. If the message reappears after having turned the power off and
on, have the battery checked and/or replaced by a qualified service per¬
son. The instrument can still be used for accurate measurements by run¬
ning the SELF CAL MEASUREMENTS routine from the SERVICE MENU
after the instrument has warmed up for at least 20 minutes.
To run the SELF CAL MEASUREMENTS routine, press the left and right
VERTICAL MODE buttons (CH 1 and CHOP/ALT). Press the ADD button
(down-arrow) to underline SELF CAL MEASUREMENTS. Press the CH 2
button (RUN) to start the routine, then CH 4 (QUIT) or CLEAR MEAS'MT
button to return to the normal oscilloscope mode.
1-6
2245A Operators

Introduction
Repackaging for Shipment
Save the original shipping carton and packing material in case it is ever
necessary to reship the Instrument by a commercial transport carrier, if
the original materials are unfit or not available, then repackage the Instru¬
ment using the foiiowing procedure.
1. Use a corrugated cardboard shipping carton with a test strength of at
least 275 pounds and an inside dimension at least six inches greater
than the instrument dimensions.
2. if instrument is being shipped to a Tektronix Service Center, enclose
the following information: owner’s address, name and phone number
of a contact person, type and serial number of the instrument, reason
for returning, and a complete description of the service required.
3. Completely wrap the instrument with polyethylene sheeting or equiva¬
lent to protect the outside finish and keep harmful substances out of
the instrument.
4. Cushion instrument on all sides with three inches of padding material or
urethane foam, tightly packed between the carton and the instrument,
5. Seal the shipping carton with an industrial stapler or strapping tape.
6. Mark the address of the Tektronix Service Center and your own return
address on the shipping carton.
2245A Operators
1-7

SECTION 2
CONTROLS,
CONNECTORS,
AND INDICATOR
2245A Operators

Controls , Connectors, and Indicators
Crt
s
Powe
Refer to Figure 2-1 for location of items 1 through 9.
(1) POWER Switch—Turns on or off instrument power. Press for ON or
OFF.
At least one VERTICAL MODE button will light when the power is
turned on. The front-panel setup existing when the power is turned off
will return when the power is turned on again.
A INTEN Control-Adjusts the brightness of the A trace.
B INTEN Control—Adjusts the brightness of the B Delayed sweep
trace and the Intensified zone on the A trace.
4 ) FOCUS Control—Adjusts the focus of the crt displays (traces,
readout, and cursors),
TRACE ROTATION Control—Aligns the crt trace with the horizontal
graticule Sines. This is a screwdriver adjustment.
READOUT Control—Adjusts the brightness of the crt readout display
(includes ail aSphariumerics and cursors).
SCALE ILLUM Control—Adjusts the illumination level of the
graticule.
NOTE
Life of the graticule illumination lamps can be increased by
setting the SCALE ILLUM control for the minimum intensity
needed for viewing, and turning off scale illumination when
not needed.
BEAM FiND Button—Locates off-screen and overscanned displays
when the button is held in. Limits the vertical and horizontal defiection
within the display area and unblanks the crt.
2245A Operators
2-1

Controls, Connectors, and Indicators
Figure 2-1. Crt, power and display controls.
CRT—Displays waveforms and readouts in an 80 mm vertical by 100
mm horizontal graticule area.
Internal graticule lines provide parallax-free viewing of trace and
graticule lines. 0%, 10%, 90% and 100% points marked at the left
edge of the graticule aid in making rise- and fall-time measurements.
2-2
2245A Operators

Controls, Connectors, and Indicators
Refer to Figure 2-2 for location of items 10 through 17.
® CH 1 and CH 2 POSITION Controls—Adjust vertical position of the
Channei 1 and Channel 2 waveform displays.
U y MODE Buttons—Select the vertical channels for display (CH 1, ADD
channels 1 and 2, CH 2, CH 3, and CH 4). The CHOP/ALT MODE
button selects method for switching input channels on the display
(chopped or alternating),
Except for CHOP/ALT modes, pressing an unlit mode button turns on
the mode, and pressing a lit button turns off the mode. CHOP is se¬
lected when the CHOP/ALT button is lit; ALT is selected when the
button Is not lit.
CH 1, CH 2, CH 3, and CH 4—Select vertical channels for display.
At least one of the channels or ADD is always on and cannot be turned
off until another channel is turned on.
CHOP/ALT—In the CHOP mode the display chops between selected
input channels at a rate of about 625 kHz. In the ALT mode, the se¬
lected channels are displayed in sequence (alternating at the end of
each sweep).
ADD—Displays the algebraic sum of the Channel 1 and Channel 2
Input signals. The ADD display is in addition to any other selected
channel displays, In the ADD mode, a plus sign (+) is displayed
between the Channel 1 and Channel 2 VOLTS/DIV readouts.
NOTE
In ADD mode when AUTO LEVEL TRIGGER MODE or
CHOP VERTICAL MODE is selected, the algebraic sum of
Channel 1 and Channel 2 display provides the Internal signal
source for the trigger system when the trigger source Is
VERT.
2245A Operators
2-3

Figure 2 - 2 . CH 1 and CH 2 vertical controls and indicators.
12) Channel 1 and Channel 2 VOLTS/DIV Switches—Select cali¬
brated deflection factors for Channel 1 and Channel 2 from 2 mV per
division to 5 V per division in a 1-2-5 sequence of 11 steps,
The switches are detented, continuous-rotation controls with no end
stops. The VOLTS/DIV readouts reflect attenuation factors of coded
attenuator probes connected to the vertical inputs.
2~4
2245A Operators