Tektronix CFG250 User manual

TEK
OPERATOR'S MANUAL
070-6738-00
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CFG250
FUNCTION GENERATOR
COMMITTED TO EXCELLENCE

TEK
070-6738-00
PRODUCT GROUP 46
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CFG250
FUNCTION GENERATOR
OPERATOR'S MANUAL
Please Check for
CHANGE INFORMATION
at the Rear of This Manual
First Printing November 1987
COMMITTED TO EXCElLENCE

Copyright ©1987 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 issued and pending.
TEKTRONIX, TEK, SCOPE-MOBILE,
a~d i! are registered
trademarks of Tektronix, Inc.
Printed
in Hong Kong. Specification and price change privileges
are reserved.
INSTRUMENT SERIAL NUMBERS
Each instrument has aserial number on apanel insert, tag, or
stamped on the chassis. The first number or letter designates
the
country of manufacture. The last five digits of the serial num-
ber are assigned sequentially and are unique to each instru-
ment. 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.
HK00001 Hong Kong
100000 Tektronix Guernsey,
Ltd., Channel Islands
200000 Tektronix United Kingdom,
Ltd., London
300000 Sony/Tektronix, Japan
700000 Tektronix Holland, NV, Heerenveen,
The Netherlands

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Certificate of the Manufacturer/Importer
We hereby certify that the CFG250 FUNCTION GENERATOR
AND ALL INSTALLED OPTIONS
complies with the RF Interference Suppression requirements of
Amtsbl.-Vfg 1046/1984.
The German Postal Service was notified that the equipment is being
marketed.
The German Postal Service has the right
to re-test the series and to
verify that it complies.
TEKTRONIX
Bescheinigung des Herstellers/lmporteurs
Hiermit wird bescheinigt, daB der/die/das CFG250 FUNCTION
GENERATOR AND ALL INSTALLED OPTIONS
in Ubereinstimmung mit den Bestimmungen der Amtsblatt-Verfugung
1046/1984 funkentstort ist.
Der Deutschen Bundespost wurde das Inverkehrbringen dieses Gerates
angezeigt und die Berechtigung zur UberprufUng der Serie auf Einhalten
der Bestimmungen eingeraumt.
TEKTRONIX

NOTICE to the user/operator:
The German Postal Service requires that Systems assembled
by the
operator/user of this instrument must also comply with Postal
Regulation, Vfg. 1046/1984,
Par. 2, Sect. 1.
HINWEIS fUr den Benutzer/Betreiber:
Die vom Betreiber zusammengestellte Anlage, innerhalb derer dies
Gerat eingesetzt wird, muB ebenfalls den Voraussetzungen nach Par. 2,
Zift. 1der Vfg. 1046/1984 genugen.
NOTICE to the user/operator:
The German Postal Service requires that this equipment, when used in a
test setup, may only be operated if the requirements of Postal
Regulation, Vfg. 1046/1984, Par. 2, Sect. 1.7.1 are complied with.
HINWEIS
fUr den Benutzer/Betreiber:
Dies Gerat dart in MeBaufbauten nur betrieben werden, wenn die
Voraussetzungen des
Par. 2, Zift. 1.7.1 der Vfg. 1046/1984 eingehalten
werden.

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CONTENTS
Page
List of Illustrations
ii
List of Tables ii
The CFG250 2MHz Function Generator,
abrief description iii
SECTION 1-PREPARATION FOR USE
1.O-Operator'sSafety Summary 1-1
1.1-Line Voltage Selection 1-4
1.2-Grounding the Equipment 1-4
1.3-Fuses ......... .. 1-4
SECTION 2-0PERATION
2.00-Front Panel Organization 2-1
2.05-Controls, Connectors, and Indicators 2-2
2.10-Rear Panel Organization 2-4
2. 11-Controls Connectors, and Indicators 2-5
2.20-Functions and Applications 2-6
2.21-Sine Wave 2-6
2.22-Square Wave 2-7
2.23-Sawtooth Wave 2-8
2.24- TTL 2-9
2.25-Sweep Output 2-9
2.26-Voltage Controlled External Sweep Input 2-9
SECTION 3-SPECIFICATIONS
3.1-General Characteristics 3-1
3.2-Electrical Characteristics 3-3
CFG250 Operator's

Page
SECTION 4-0PERATOR MAINTENANCE
SECTION 5-BASIC THEORY OF OPERATION
SECTION
6-GLOSSARY OF TERMS
LIST OF ILLUSTRATIONS
Figure 2-1. Front Panel 2-1
Figure
2-2. Rear Panel 2-4
Figure 2-3. Output Test Configuration 2-7
Figure 5-1. Circuit Block Diagram 5-1
LIST OF TABLES
Table 2-1. Waveform chart for symmetry
and invert controls 2-3
ii
CFG250 Operator's

THE CFG250 2 MHz FUNCTION
GENERATOR
The TEKTRONIX CFG250 2MHz FUNCTION GENERATOR pro-
duces sine, square and sawtooth waves and
TTL signals. Its ap-
plications include testing and calibration of audio, ultrasonic, and
servo systems. The CFG250's sweep function can be internally
controlled
or controlled with an external DC level. Duty cycle, DC
offset, sweep rate, sweep width and amplitude are controlled by
the operator. The CFG250 has an output
frequency range of
0.2 Hz to 2MHz.
The TEKTRONIX CFG250 has alocking, multi-position handle
that folds under
the instrument to allow stacking with other in-
struments
of the same series. The instrument is delivered with a
power
cord and an Operator's manual.
Should you need
more information about your CFG250 2MHz
Function Generator
or other Tektronix products: contact the
nearest Tektronix Sales Office
or Distributor, consult the
Tektronix
product catalog, or in the U.S., call the Tektronix
National Marketing Center.
CFG250 Operator's iii

SECTION 1
PREPARATION
FOR USE
CFG250 Operator'S

Preparation for Use
OPERATOR'S SAFETY SUMMARY
The general safety information in this part of the summary is for
both operating
and service personnel. Specific warnings and cau-
tions wili be found throughout the
manual where they apply and
do not appear in this summary.
Terms Used In This Manual
CAUTION
statements identify conditions or practices that could
result in
damage to the equipment or other property.
WARNING
statements identify conditions or practices that could
result in personal injury
or loss of life.
Terms
As Marked on Equipment
CAUTION indicates apersonal injury hazard that is not immedi-
ately accessible as one reads the markings.
or ahazard to prop-
erty. including
the equipment itself.
DANGER indicates apersonal injury hazard immediately accessi-
ble as one reads the marking.
Symbols
In This Manual
This symbol indicates where applicable cautionary
or
other information is to be found.
CFG250 Operator's
1-1

Preparation for Use
Symbols As Marked on Equipment
~ DANGER -High Voltage
@Protective ground (earth) terminal.
AATTENTION -Refer to Manual.
rh Chassis ground.
Power Source
This product is intended to operate from apower source that
does not apply
more than 250 volts rms between the supply con-
ductors
or between either supply conductor and ground. Apro-
tective 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
aproperly wired
receptacle before connecting to the product
input
or output terminals. Aprotective 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 accessible
conductive parts (including knobs and controls that
may appear
to be insulating) can render an electric shock.
1-2
CFG250 Operator's

Preparation for Use
Use the Proper Power Cord
Use only the power cord and connector specified for your prod-
uct.
Use only apower cord that is in good condition.
For detailed information on power cords and connectors see
Figure 2-2.
Use the Proper Fuse
To avoid fire hazard, use only afuse of the correct 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.
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 pan-
els properly installed.
CFG250 Operator's
1-3

Preparation for Use
1.1-Line Voltage Selection
This product is intended
to operate from apower source that
does not supply
more than 250 Vrms between the supply con-
ductors
or between either supply conductor and ground. Normal
USA voltage is 120 VAC. For line voltage selection setting, see
Figure
2-2.
1.2-Grounding the Equipment
Aprotective ground connection, the third wire
in the power cord,
is necessary
for safe operation. To avoid electrical shock, plug
the power cord into aproperly wired receptacle before making
any connections to the equipment input or output terminals. Do
not remove the ground lug from the power cord for any reason.
Use only the power cord and connector specified for this equip-
ment.
1.3-Fuses
To avoid fire hazard, use only afuse of the specified type, volt-
age rating and current rating
for this equipment. (See 2.11 Con-
trols. Connectors. and Indicators.)
1-4 CFC250
Operator's

SECTION 2
OPERATION
CFG250 Operator'S
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Operation
2.0S-Controls, Connectors, and Indicators
(1) POWER button -Push in to turn CFG250 on. Asecond push
turns the generator off.
(2) POWER on light -Indicates apower on condition.
(3)
FUNCTION buttons -The sine, square or sawtooth buttons
determine the type of signal provided at the MAIN output
connector.
(4) RANGE (Hz) buttons -These buttons determine the fre-
quency range of the signal at the MAIN output connector.
(5)
FREQUENCY control -This variable control determines the
frequency of the signal at the MAIN output connector within
the range set by the
RANGE buttons.
(6) AMPLITUDE control -This variable control, depending on
the position
of the VOLTS OUT button, determines the level
of the signal at the MAIN output connector.
(7) VOLTS OUT range button -Push in for AMPLITUDE control
range of a
to 2 Vp-p, open circuit, or a to 1 Vp-p into a50
nload. Set to the out position for an AMPLITUDE control
range of a
to 20 Vp-p, in an open circuit, or a to 10 Vp-p
to a50 nload.
(8)
INVERT button -Pushing this button in causes the signal at
the MAIN output
connector to be inverted. When the DUTY
control is being used, the invert switch determines which
half
of the output waveform will be affected. Table 2-1
shows that relationship.
(9)
DUTY control -Pull this control out to activate. At maxi-
mum ccw the output signal, including TTL, will be
symmetrical. Turning the control
cw will change the period
of half the waveform as determined by the INVERT button.
The period of the unaffected half of the
waveform will still
be
determined by the FREQUENCY multiplier and RANGE
buttons. When the control is pushed in, the signal outputs
are symmetrical at all control settings.
2-2
---------
CFG250 Operator's

Operation
----------------_._---~
Table 2-1
Waveform chart for symmetry and
invert controls
DUTY eeN
DUTY eN
Invert Out Invert In Invert Out
Invert In
Square
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TTL
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(10) DC OFFSET -Pull this control out to activate. The DC OFF-
SET control sets the DC level and polarity of the signal at
the MAIN output. When the control is pressed
in the signal
is centered at zero Vdc.
(11)
SWEEP button -Push in for internal sweep. This button
activates
the sweep rate and sweep width controls. When
the button is
set out the CFG250 will accept signals from its
EXTERNAL
SWEEP input connector on the rear panel.
(12)
SWEEP RATE -This control adjusts the rate of the internal
sweep generator and the repetition rate of the burst gate.
(13)
SWEEP WIDTH -This control adjusts the amplitude of the
sweep.
(14)
MAIN output connector - BNC output connector for sine
wave, square wave and sawtooth wave signals.
~
The outside (ground) of the MAIN and SYNC output con-
nectors are connected through the equipment
to the
power source ground. Check the grounding system
of the
receiving equipment before connecting the CFG250.
(15) SYNC (TTL) output connector - BNC output connector for
TTL signals.
CFG250 Operator's
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Operation
2.11-Controls, Connectors, Indicators
(1 R) LINE FUSE -Provides protection for equipment malfunction
or overload. (MOL 0.2 A, 250V slow-blow for 100-120 V
range
or MOL 0.1 A, 250 V slow-blow for 220-240 V
range) .
(2R) POWER INPUT -Input connector for power cord -safety
coded.
(3R) EXTERNAL SWEEP input connector -Input BNC connector
for voltage-controlled sweep. Signals applied to this con-
nector will control the output frequency when the SWEEP
button is set to the out position. An input of 0 to +1 OV DC
sweeps the signal at the MAIN output down two decades
(100:1
). The total sweep range is also dependent on the
base
frequency and the desired sweep direction.
~
The outside (ground) of the EXTERNAL SWEEP input
connector is connected through the equipment to the
power source ground. Check the grounding system
of the
input equipment before connecting the CFG250.
(4R) LINE VOLTAGE SELECTOR -These selectors connect the
internal wiring
for various line voltages.
~
Observe and set LINE VOLTAGE SELECTORs for the cor-
rect voltage level before operating the equipment.
CFG250 Operator's
2-5

Operation
2.20-Functions and Applications
2.21-Sine Wave
Asine wave output is obtained from the MAIN output connector
when the sine wave FUNCTION button is pushed in and one of
the frequency RANGE buttons is pushed in. The frequency of the
wave is set by the combination of the RANGE button and the
variable FREQUENCY control. The output may be checked with
an oscilloscope such as the Tektronix 2225 or equivalent. Pro-
ceed as follows:
1. To operate CFG250 for sine wave output, the controls
should be set as follows:
CONTROL
POWER button
RANGE (Hz) button
FREQUENCY Dial
DUTY control
DC OFFSET control
AMPLITUDE control
INVERT button
VOLTS OUT button
FUNCTION button
SWEEP button
LINE VOLTAGE SELECTORs
SETTING
On (pressed in)
1 KHz button pressed in
1.0
In or fully ccw
In or centered
Centered
Out
Out (0-20 position)
Sine wave button pressed in
Out
Check power outlet for
power line range (90-132 or
198-250).
The cable connection is shown in Figure 2-3.
2. Set the oscilloscope VOLTS/DIV to 2 V, the SEC/DIV to
0.2 ms and the rest of the controls to normal operating
position.
3. The output frequency can be calculated by taking the
reciprocal of the waveform period.
4. The output can be set precisely with the Tektronix CFC250
Frequency Counter by connecting the output of the
2-6 CFG250 Operator's