Tektronix 3933A User manual

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Publication Date: March 1991
Document Number: 3933A-900-01 Rev. A

nformation

WARRANTY

Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a
period of 1 year from date of shipment.

Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables,
rechargeable batteries, diskettes, and documentation.

During the warranty period, we will, at our option, either repair or replace any product that proves to be de­fective.

To exercise this warranty, write or call your local Keithley representative, or contact Keithley headquarters in
Cleveland, Ohio. You will be given prompt assistance and return instructions. Send the product, transporta­tion prepaid, to the indicated service facility. Repairs will be made and the product returned, transportation
prepaid. Repaired or replaced products are warranted for the balance of the original warranty period, or at
least 90 days.

LIMITATION OF WARRANTY

This warranty does not apply to defects resulting from product modification without Keithley’s express writ­ten consent, or misuse of any product or part. This warranty also does not apply to fuses, software, non-re­chargeable batteries, damage from battery leakage, or problems arising from normal wear or failure to follow
instructions.

THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIE S, EXPRESSED OR IMPLIED, INCLUDING
ANY IMPLIED WARRANTY

OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. THE

REMEDIES PROVIDED HEREIN ARE BUYERS SOLE AND EXCLUSIVE REMEDIES.

NEITHER KEITHLEY INSTRUMENT S, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR
ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL OR CONSEQ

UENTIAL DAMAGES ARISING OUT
OF THE USE OF ITS INSTRUMENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS
BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAM­AGES SHALL INCLUDE, BUT ARE NOT LIMITED TO: COSTS OF REMOVAL AND INSTALLATION,
LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON, OR DAMAGE TO PROPERTY.

INSTRUMENTS

Instruments Division,

WEST GERMANY: KeithIey Instruments GmbH l Heiglhofsk. 5 l Munchen 70 l 089-71002-0
GREAT BRITAIN:
FRANCE KeitbIey Inskuments SARL -3 AlIee des Garays l BP. 60 l 91124 PaIaiseau/ZL l 1-6-OI15 155 l Telex M)O 933 l Fax l-6-0117726
NETHERLANDS:
SWITZERLAND: Keithley Inskunents SA l Kriebacbsk. 4 l 8600 Dubendorf
AUSTRIA: KeitbIey Inskuments GesmbH l Rosenbugelskasse 12 l A-1120 Vienna l (0222) 84 65 48 l Telex: 131677 l Fax (0222) S403597
ITALY: KeitbIey Instruments SRL l Vi&S. G~gnano 4/A l u)146 Milano l 02-4120360 or M-4156540 l Fax: [phone]

Keithley Instruments, Inc. l 28775 Aurora Road l Cleveland, Ohio 44139 l [phone] l Fax: [phone]

KeitbIey Instruments, Ltd. l The Minster l 58, Porknan Road l Reading, Berkshire RG 3 IFA -01144 734 575 666 l Fax: [phone]

Keitbley Instruments BV l AveIingen West 49 l 4202 MS Gorinchem . P.0. Box559 l 4200 AN

.01-821-9444 l

l Telex 52-12160 l

Telex 828 472. Fax [phone]

Fax: [phone]

GorInchem .01830-35333 l

Telex: 24 684. Fax OlS30-30821

Operator’s Manual

Model 3933A

Phase Shifter

01991, Keithley Instruments, Inc.

All Rights Reserved

Instruments Division

Cleveland, Ohio, U. S. A.

Document Number: 3933A-900-01

All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc.
Other brand and product names are trademarks or registered trademarks of their respective holders.

Safety Precautions

The following safety precautions should be observed before using the Model 3933A Phase Shifter and any associated
instruments.

This instrument is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety
precautions required to avoid possible injury. Read over this manual carefully before using the instrument.

Exercise extreme caution when a shock hazard is present at the test circuit. The American National Standards Institute
(ANSI) states that a shock hazard exists when voltage levels greater than 30V rms or 42.4V peak are present. A good

safety practice is to expect that hazardous voltage is present in any unknown circuit before measuring.

Inspect the connecting cables and test leads for possible wear, cracks, or breaks before each use.

For maximum safety, do not touch the test cables or any instruments while power is applied to the circuit under test.
Turn off the power and discharge any capacitors before connecting or disconnecting cables from the instrument.

Do not touch any object which could provide a current path to the common side of the circuit under test or power line
(earth) ground. Always make measurements with dry hands while standing on a dry, insulated surface capable of with­standing the voltage being measured.

Do not apply more than 42V peak between the outer shell of any BNC connector and chassis ground.

Instrumentation and accessories should not be connected to humans.

Table of Contents

SECTION 1

1.1 SUMMARY

1.2 FEATURES.......................................~

1.3 WARRANTYINFORMATION

1.4 ~ALADDENDA

1.5

1.6 TJNPACKINGANDREPACKING

1.6.1 Unpacking

1.6.2 ShipmentContents..

1.6.3 InstructionManual

1.6.4

1.7

1.8

SECTION 2

2.1 INTRODUCTION....‘.

2.2 INSTALLATION

2.2.1 InstallationLocation..

2.2.2 Fan..

2.3 LINE POWER SUPPLY AND GROUNDING

2.3.1

2.3.2

2.4

2.5

2.5.1

2.5.2 TypicalTestConnections

2.5.3 OperatingExamples

- General Information

..................................................................

....................................................

..........................................................

SAFETYTERMSANDSMLlBOLS

.................................................................

.........................................................

...........................................................

Repacking For Shipment
OPTIONALACCESSORIES
SPECIFICATIONS

.............................................................

....................................................... l-2

......................................................

- Getting Started

.........................................................

..............................................................

........................................................

.....................................................................

LinePowerSupply

Grounding
HANDLINGPRECAUTIONS
BASICOPERATION

Front Panel Summary

.................................................................

...........................................................

.....................................................

............................................................

......................................................... 2-3

......................................................

..........................................................

..................................................

.................................................

...........................

..........................................

l-1
l-l
1-2
1-2
1-2
1-2
1-2
1-2
1-2

l-2
1-3

2-l
2-l
2-l
2-l
2-2
2-2
2-3
2-3
2-3

2-3
2-3

SECTION 3

3.1

3.2

3.2.1

3.2.2

3.2.3

3.2.4

3.2.5

3.2.6

3.3

3.4

3.4.1

LNTRODUCTION
FRONT PANEL AND REAR PANEL DESCRIPTION

Input and Output Connections

InputConnections

Output Connections

GPIB Bus (Input/output Connector)

FrontPanelDescription

RearPanelDescription
STARTUP
OPERATINGPROCEDURES

Setting Parameters Using Numeric Keys

- Operation

..............................................................

..................................................

...........................................................

..........................................................

..............................................

........................................................

........................................................

....................................................................

.....................................................

...................................

.........................................

; .

3-1
3-l
3-l
3-1
3-3
3-4
3-4
3-11
3-14
3-15
3-15

3.4.2 Setting Parameters with the MODIFY Controls

3.4.3 ErrorCodes

3.4.4 Amplitude Units Conversion

3.4.5 Amplitude Programming

3.4.6

3.4.7 AC Amplitude and DC Offset Relational Restrictions

3.4.8 Waveform Selection, Square-Wave Duty Cycle, and Synchronous Output

3.4.9

3.5

3.5.1 Sweep Phase and Sweep Output Relationships

3.5.2

DC Offset Progr amming .......................................................

Mark, Span, and Phase Parameter Programming

SWEEPOPERATIONS..

OutputRangeMode..

.............................................

...................................................

......................................................

........................................................

.......................................................

......................................

................................. 3-25

..................................... 330

......................................

.

..................

..................

3-16
3-17

3-22
3-25

3-25

3-28

3-30
3-32
3-33

List of Illustrations

SECTION 2

Figure 2-l
Figure 2-2
Figure 2-3

SECTION 3

Figure 3-1
Figure 3-2
Figure 3-3
Figure 3-4
Figure 3-5
Figure 3-6
Figure 3-7
Figure 3-8
Figure 3-9
Figure 3-10

- Getting Started

LineFilter ...............................................................

FrontPanelSummary
TypicalConnections

......................................................

.......................................................

- Operation

LogicInputCircuit ........................................................

AnalogInputCircuits ......................................................

Typical Digital I/O Interconnections
Sweep Marker and Sweep Synchronous Outputs
Waveform Synchronous Outputs

Model3933AFrontPanel ...................................................

Model3933ARearPanel ....................................................

Waveforms and Their Phase Definitions
Relational Range for Allowed AC Amplitude Voltage and DC Offset Voltage
Phase Relationship Between Waveform and Output

...........................................

..................................

.............................................

........................................

...............................

............

2-3
2-4
2-5

3-1
3-2
3-2
3-3
3-3
3-5
3-12
3-24
3-26
3-29

List of Tables

SECTION

Table 2-l

SECTION

Table 3-l
Table 3-2
Table 3-3 AC + DC Minimum Amplitude, Resolution, and Accuracy (open load)

2 - Getting Started

Fuse Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3 - Operation

Main Synthesizer Amplitude Range When DC Offset is 0 Volts
DC-only Voltage Setting Range, Resolution, and Accuracy (open load, 18 to 28°C)

....................... 3-18

.................

2-3

......... 3-18

3-19

SECTION

General Information

1 .l SUMMARY

The Model 3933A Phase Shifter is designed for use in con­junction with a Model 3930A Multifunction Synthesizer.
Together, Mode13933A and Model 3930A form a variable
phase, multi-phase oscillator with a phase setting range

from -360 to 360”. Phase resolution is 0.1”. The frequency

range is the same as the Model 3930A.

Five output waveforms,
available. Each waveform has a maximum output of 30V
p-p (no-load) and 15V p-p into 5OQ. Waveform and am­plitude may be set independently of the Model 3930A or
another Model 3933A. Waveform output is isolated from
the Model 393OA, or another Model 3933A, allowing a
wide range of applications. Multiple 3933A units may be
combined with a single 3930A to create a multi-phase os­cillator system.

Phase output is directly synthesized by a custom LSI digi­tal IC, resulting in high accuracy and stability, and short
phase switching time.

In addition to phase sweep and amplitude modulation
(AM), variable square-wave duty cycle is also provided.

Parameter settings are easily made using either the front
panel keys and/or the modify knob.

$,2/,-rL,n,and\jare

The Model 3933A is equipped with a standard GPIB

(IEEE-488) interface, and can be programmed over the

bus to produce the same operating modes and parame-

ters that can be controlled from the front panel.

The Model 3933A uses a two-line, 40-character liquid

crystal display to indicate selected functions, parameters,
and pertinent messages.

1.2 FEATURES

Wide phase setting range: -360” to 360”, with resolu­tion of 0.1”.
High output and high AC voltage accuracy: 30V p-p
(no load), 15V p-p into 5OQ ti.5% (-5OkHz, sine wave,
above 3V p-p).
A total of 5 units of Model 3933A may be combined
with a Model 3930A to provide up to a 6-phase oscilla­tor system.
Two-line, 40-character liquid crystal display.

Five output waveforms:
Variable square wave duty cycle (5% to 95%, below
100 kHz).
Multiple phase sweep functions. Each setting digitally
synthesized according to input from the front panel
numeric keypad or the modify dial.
Low distortion ratio (<O.l%, 1OHz to lOOkI&, above

30.0mV p-p, AUTO output range mode).
Isolated waveform output.

Battery backed-up memory can retain up to 10 groups
of parameters. At power-on, it will automatically set

%,2/,l,n,and\l.

l-l

SECTION 1
General Information

itself according to those parameters which were in ef­fect immediately prior to the last power shut-off.
GPIB interface included as standard equipment.
Output mode switchable from automatic (AUTO) to
fixed (FXD).
A wide range of front and rear panel I/O interconnec­tions to control or modify signal operations and pa­rameters.

, .3 WARRANTY INFORMATION

Warranty information is located on the inside front cover
of this instruction manual. Should your Model 3933A re­quire warranty service, contact the Keithley representa­tive or authorized repair facility in your area for further
information. When returning the instrument for repair,
be sure to fill out, and include, the service form at the back
of this manual in order to provide the repair facility with
the necessary information.

1.4 MANUAL ADDENDA

1.6 UNPACKING AND REPACKING

1.6.1

After carefully unpacking the instrument from its ship­ping carton, inspect it for obvious signs of physical dam-

age. Report any such damage to the shipping agent im-

mediately. Save the original packing carton for storage or

possible reshipment.

1.6.2

The following items are included with every Model
3933A order:

l

Model 3933A Phase Shifter

l

Model 3933A Instruction Manual

l

Power Cord

l

Fuse 0.5A, WOV, 5.2 x 20mm (FU-96-2)

l

Digital I/O interconnection cable (CA-941

l

BNC to BNC signal cable (Keithley Model 7051-2, -5, or

-10)

l

Additional accessories as ordered

Unpacking

Shipment Contents

Any improvements or changes concerning the instru­ment or manual, will be explained in an addendum in­cluded with the unit. Be sure to note these changes and
incorporate them into the manual before using or servic­ing the unit.

1.5 SAFETY TERMS AND SYMBOLS

The following safety terms and symbols are found on the
instrument, or used in this manual.

The A 1 symbol on the instrument indicates that the
user should refer to the operating instructions.

The WARNING heading used in this manual explains
dangers that might result in personal injury or death. Al­ways read the associated information carefully before
performing the indicated procedure.

1.6.3

Instruction Manual

If an additional instruction manual is required, order the
manual package, Keithley part number 3933A-901-00.
The manual package includes an instruction manual and
any pertinent addenda.

1.6.4

Repacking For Shipment

Should it become necessary to return the Model 3933A
for repair, carefully pack the unit in its original packing
carton or the equivalent. Be sure to use a cardboard box of
sufficient strength.

Include the following information:

l

Advise as to the warranty status of the instrument.

l

Write ATTENTION REPAIR DEPARTMENT on the

shipping label.

o Fill out and include the service form located at the back

of the manual.

The CAUTION heading used in this manual explains
hazards that could damage the instrument card. Such
damage may invalidate the warranty.

l-2

1.7 OPTIONAL ACCESSORIES

The following accessories are available for use with the
Model 3933A.

General Information

SECTION 1

Models

3900-l and 3900-2 Rack Mounting Kits:

The
Model 3900-l mounts one Model 3933A in a standard 19
inch rack. The Model 3900-2 mounts two Model 3933A’s,
side by side, or one Model 3933A and one Model 3940A
side by side. Both kits include all necessary hardware for
proper rack mounting of the instruments.

Model 7007 Shielded IEEE-488 Cables:

The Model
7007-l (lm, 3.3ft.) and Model 7007-2 (2m, 6.6 ft.) can be
used to interface the Model 3940 to the IEEE-488 bus.

Model 7051-2 BNC-to-BNC Cable:

The Model 7051-2 is a
50 Ohm BNC-to-BNC cable (RG-58C), 2 feet (0.6m) in
length. The Model 7951-2 is terminated with male BNC
connectors at both ends.

Model 7051-5 BNC-to-BNC Cable: The Model 7051-5 is a
50 Ohm BNC-to-BNC cable (RG-58C), 5 feet (1.2m) in
length. The Model 7951-5 is terminated with male BNC
connectors at both ends.

Model 7051-10 BNC-to-BNC Cable:

The Model 7051-10
is a 50 Ohm BNC-to-BNC cable (RG-58C), 10 feet (2.4m)
in length. The Model 7951-10 is terminated with male
BNC connectors at both ends.

1.8 SPECIFICATIONS

Detailed Model 3933A specifications may be found in
Appendix A.

l-3

SECTION 2

Getting Started

2.1 INTRODUCTION

This section contains basic information on installation

and power line connections. It also provides typical sim-

ple operating examples. The Model 3933A uses an in-line electrical noise filter, but

2.2 INSTALLATION

The following paragraphs discuss Model 3933A installa-

tion. Improper installation will adversely affect the life,
reliability, and safety of the unit.

The Model 3933A weighs about 10 pounds. Be careful
when carrying the unit or mounting it in a rack.

ment must be free of dust and vibration, and the Model

393314 must not be exposed to direct sunlight.

pulse noise or strong magnetic or electric fields may

cause incorrect operation of the unit. Do not install the
unit near a source of pulse noise or strong magnetic or
electric fields.

WARNING

The guards on the rear panel of the

designed to protect rear panel connectors
and should not be used as legs for installa­tion. Do not stand the unit vertically on the
rear guards, because it may fall over, causing
instrument damage or personal injury.

unit are

2.2.1 Installation Location

The allowable ambient temperature and humidity
ranges for the Model 3933A are:

Operating: 0” to 4O”C, 10 to 9O%RH
Storage: -10” to 5O”C, 10 to 8O%RH.

2.2‘2

The Model 3933A is air-cooled by a fan. Insufficient air

flow may cause a component in the unit to fail. Follow the
instructions given below.

Fan

Be sure to install the unit in a location that satisfies these Observe
temperature and humidity conditions. Also, the environ-

vent damage to the unit:

CAUTION

the following precautions to pre-

2-l

SECTION 2

Getting Started

An air intake port is provided on the rear
panel of the unit. Allow a space of at least
four inches between the rear panel and a
wall or other obstruction.

An exhaust port is provided on the bottom
panel of the unit. Install the unit on a rigid,
flat surface, and avoid installing it on soft
material, such as a cushion. Be careful not to
insert foreign material between the bottom
of the unit and the surface underneath. An­other exhaust port is located on the top panel
of the unit. Be careful not to block the top
port by placing an object on top of the unit.

Avoid mounting two or more units vertically
(for example, when using two or more units
synchronously). Placing one unit on top of
another will obstruct the exhaust port.

Dust collecting in the fan filter will prevent
sufficient air flow. In a clean operating envi-

ronment, wash the filter with a mild deter­gent every three months. When operating
the unit in a dusty environment, wash the fil­ter with a mild detergent at least once a
month.

Immediately turn off the power to the unit if
the fan ceases to operate. Operating the in­strument with an inoperative fan may result
in damage to the instrument.

2.3

LINE POWER SUPPLY AND
GROUNDING

position. Wait at least five seconds before turning the
power back on after turning it off.

WARNING
Disconnect the power cord from the instru­ment before changing the supply voltage
setting.

CAUTION
Be sure to set the line voltage switch to the
correct position for the line power voltage to
be used. Operating the instrument on an in­correct voltage may cause damage to the unit.

LINE Receptacle Connection

Connect the supplied power cord to the rear panel LINE
receptacle and to a grounded AC power receptacle sup­plying the correct voltage.

WARNING
The Model 3933A is equipped with a 3-wire
power cord that contains a separate ground
wire and is designed to be used with
grounded outlets. When proper connections
are made, instrument chassis is connected to
the power line ground. If the AC outlet is not
grounded, the rear panel ground terminal
must be connected to safety earth ground us­ing #lSAWG (or larger) wire before use.

2.3.1 Line Power Supply

The Model 3933A operates with lOOV, 12OV, 22OV, or
24OV, &lo%, 48 to 62Hz, single-phase AC power supply.
The power consumption is about 38 VA.

Line Voltage Selector Switch

The Line Voltage Selector switch on the rear panel allows
you to change the operating voltage of the power supply.
The standard setting of the switch is the same as the volt­age in the country to which the unit is shipped.

To change the power supply voltage, first disconnect the
line cord, and set the supply voltage switch in the correct

2-2

LineFuse

The line fuse protects the instrument from over-current
situations. To replace the fuse, first disconnect the line
cord, then unscrew the center cap with a small screw­driver. Replace the blown fuse only with the type listed in

Table 2-1, then replace the fuse cap.

WARNING
Disconnect the line cord from the instru­ment before replacing the fuse.

CAUTION

* Use only a fuse of the rating listed in Table

2-1, or instrument damage may occur.

SECTION2

Getting Starfed

Table 2-l. Fuse Replacement

220,240V

NOTE: Fuses are 5 x 20mm and have 25OV, normal blow ratings.

2.3.2

To prevent the possibility of electrical interference,

the Model 3933A using the grounding terminal

If the Model 3933A is not connected to a
grounded AC outlet, be sure to connect the
grounding terminal on the rear panel to
safety earth ground using minimum
#18AWG wire before use.

1 0.5A

Grounding

WARNING

1 FU-96-1

When the panel or case becomes dirty, clean it with a soft

cloth. If the panel or case is too dirty for cleaning with a
dry cloth, lightly dampen the cloth in mild detergent so­lution, and wipe the panel or case with the damp cloth.

Never use solvents such as thinner or benzene, or chemi-

cal dust cloths, as these
panel surfaces.

may

damage the case or front

2.5 BASIC OPERATION

The following paragraphs summarize front panel operat­ing controls, give typical test connections, and discuss

typical operating examples for the Model 3933A.

2.5.1 Front Panel Summary

Figure 2-2 summarizes each front panel feature. For de­tailed information on each operating feature, refer to Sec­tion 3.

2.5.2

Typical Test Connections

The Model 3933A uses the line filter circuit shown in Fig­ure 2-l. The maximum leakage current at 250V/60Hz is

1mA rms. Touching the metallic part of the chassis of the

unit may, therefore, cause an electric shock if the Model

3933A is not properly grounded.

I- II

1 -I-l*

-1 I

Power

inpur

Figure 2-1. Line Filter

transformer

2.4 HANDLING PRECAUTIONS

A flat keyboard, coated with a polyester film, forms the
control panel surface of the Model 3933A. Be careful not
to damage the keyboard surface by cutting it with a sharp
instrument or touching it with a hot object.

Figure 2-3 shows typical tests connections between the
Model 3933A Phase Shifter and a device under test. Note

that 50 ohm characteristic impedance cables, such as the

Model 7051, should be used for all signal connections.

2.5.3 Operating Examples

The following examples give step-by-step instructions

for setting basic Model 3933A operating parameters,

Example 1: Selecting the Waveform Type (Function)

The waveform type can be selected using the FCTN key,

of the ENTRY group, as follows:

1. Press FCTN and note that the instrument displays
the existing function and the available functions
(sine, triangular, square, sawtooth, DC).

2. Press the number key corresponding to the desired
function (O-5), or rotate the MODIFY knob until the
desired function number is displayed. For example,
press 3 to select the square wave function. The
waveform will immediately change to the selected
function.

3. Press DSPL to return to the normal display mode.

2-3

SECTION 2

Getting Started

SYNC OUT

DISPLAY

,*I

MODIFY
Changes

parameters,

I--

selections

3

AM IN: Enables or

;;k$Ies AM

I s

SHIFT

Adds shifted function

to some other keys

I

2 DUTY FXDBO

t-i- DUTY: Allows setting squarewave -

duty cycle

FXDBO: Fixed 50% duty cycle

RUB OUT: Deletes current

L

1

ENTRY

PHASE: Sets phase parameters

AMPTD: Sets output amplitude

OFFSET: Sets DC offset (main only)

I

-1

J

FCTN: Sets waveform type

L

SWEEP

START. Programs start

STOP. Programs stop

CTR: Sets center

SPAN: Sets span

SWEEP FCTNI Sets function

SWEEP TIME: Sets time

SWEEP OFF: Cancels sweet mode

I

. S&marker

SWEEP OPR

START: Starts sinole or

caltinuous sweep

L

I

,

1

4 e STEP SIZE

Used with modify

keys to change

parameter values

1 DSPL 1

Returns display

to normal

Sets applicable units
definition value for
parameters set with

Figure 2-2.

2-4

Front Panel Summary

SECTlON 2

Getting

Started

Model 3933A

Function

output

Figure 2-3. TypicaZ Connections

Example 2: Setting the Output Amplitude.

Use the AMPTD key, of the ENTRY group, to set the out­put voltage amplitude as follows:

Press AMPTD, and note that the instrument displays

1.
the existing amplitude and allowed amplitude
range.

2. To enter a completely new amplitude value in p-p
units, press the keys for the desired numeric value,
then press V or mV, as required. For example, to en­ter a 30mV p-p amplitude, press the following three
keys: 3 0 mV.
To simply modify the existing amplitude value, use

3.
the cursor keys and the MODIFY knob to set the
value as required.
Press DSPL to return to normal display.

4.

Example 3: Programming the DC Offset

The OFFSET key allows you to set the DC or average level

of the main synthesizer output waveform, as in the fol­lowing example:

1. Press OFFSET and note that the instrument displays
the existing offset value and allowed range.

2. Either press the numeric keys for the desired offset
value, or use the MODIFY knob and/or cursor keys
to change the value.

3. Press DSPL to return to normal display.

Example 4: Setting Phase Shift

The PHASE key allows you to set the amount of phase

shift, in degrees, of the main synthesizer output wave-

form, as in the following example:

1. Press PHASE and note that the instrument displays
the existing phase value and the allowed range.

2. Enter the desired phase shift value, or use the MOD­IFY KNOB and/or cursor keys to change the existing
value.

3. Press DSPL to return to normal display.

2-5

CTION 3

Operatio

3.1 INTRODUCTION

This section contains detailed information on front panel
and rear panel operation of the Model 3933A. For de­tailed GPIB (IEEE-488 bus) operation, refer to Section 4,
GPIB Operation, in the manual for the Model 3930A Mul­tifunction Synthesizer.

3.2 FRONT PANEL AND REAR PANEL
DESCRIPTION

3.2.1

Input and Output Connections

CAUTION
Restrictions apply to input and output signal
levels and signal types. Adhere to signal
level and load characteristics as described
below. or the instrument may be seriously
damaged.

3933A: LOGIC and ANALOG. The specifications of the
input signals are given below.

BNC LOGIC INPUTS (Rear Panel)

Logic inputs include SWEEP SINGL START IN (single­sweep start input), and SWEEP HOLD IN (sweep hold
input). Important specifications for these inputs include:

Input voltage: TTL level
Allowable maximum input voltage: OV to +5V
Circuit: See Figure 3-1, Logic Input Circuits.

(SWEEP) SINGL START IN
(SWEEP) HOLD IN

3.2.2 Input Connections

Two types of input signals may be applied through the
front and rear panel BNC input connectors of the Model

1 Fiaure 3-l.

Loaic Invut Circuit

SECTION 3

Operation

BNC ANALOG INPUT (Front Panel)

The AM IN BNC can be used to apply an external analog
input signal which controls the amplitude of the
waveform.

Input voltage range: -3V to +lV
Allowable maximum input voltage: rtl5V.
Input phase range: DC to 1OOkHz.
Input impedance: Approximately 1OkQ.
Signal ground: insulated from ground.
Circuit: See Figure 3-2, Analog Input Circuit.

+6.3V

AM IN

DIGITAL INPUT CONNECTOR (Rear Panel)

A third type of input is the DIGITAL INPUT. One digital,
36-pin, D-type input connector transfers MAIN SYN­THESIZER signals from a master Model 3930 to a Model
3933A slave unit, and between successive Model 3933A’s
in a chain of phase shifters. A jumper cable, CA-94 is re­quired to interconnect units.

The main synthesizer signal from a Model 3930A (master
unit) is applied to the DIGITAL IN connector on the rear

panel of a Model 3933A (slave unit). If an additional
phase shifter unit is chained to provide multiple phase
operation, a second cable (CA-941 is connected from the

DIGITAL OTJT of the first slave, to the DIGITAL IN on

the rear panel of the second slave unit. This may be re­peated until a maximum of 5 (five) slave units are tied to a
single master synthesizer. The DIGITAL IN and DIGI­TAL OUT signals at the rear panel of the slaves are identi­cal to the master main synthesizer output signal.

Figure 3-2.

Analog Input Circuits

3930A

CA-94

3933A

Figure 3-3. Typical Digital I/O Interconnections

Cable

Interconnection details are shown below, in Figure 3-3.

,

3933A

I

\

Next

3933A

3-2

SECTION 3

Operation

3.2.3 Output Connections

Five output signals are available from various BNC con­nectors on the Model 3933A. The specifications for the

output signals are given below.

CAUTION
Be careful not to connect an input signal to
an output connector, or instrument damage
may occur.

BNC LOGIC OUTPUTS (Rear Panel)

Logic outputs include the SWEEP SYNC OUT (sweep
synchronous output) and SWEEP MKR OUT (sweep
marker output). Specifications for these outputs are sum­marized below.

Output voltage: TTL level

Sweep MKR OUT and Sweep SYNC OUT are connected
to ground.

Circuits: See Figure 3-4.

Circuits: See Figure 3-5.

SYNC OUT

Figure 3-5.

DIGITAL OUTPUT CONNECTOR (Rear Panel)

Waveform Synchronous Outputs

One digital, 36-pin, D-type input connector transfers sig­nals among several Model 3933A’s (up to 5) in a chain of
phase shifters. A jumper cable, CA-94 is required to inter­connect units.

BNC ANALOG OUTPUT (Rear Panel)

Sweep X Drive Out (Sweep X

Axis

Drive Output)

Output voltage: OV to +lOV/no load

+5v

Figure 3-4.

9

Sweep Marker and Sweep Synchronous

SWEEP MKR OUT

SWEEP SYNC OUT

outputs

BNC LOGIC OUTPUT (Front Panel)

Waveform SYNC OUT (front panel synchronous output)
Output voltage: TTL level

Waveform SYNC OUT is electrically isolated from chas­sis ground.

Output impedance: 6OOQ
Recommended load impedance: lOkG! or more

BNC ANALOG OUTPUT (Front Panel)

Fctn Out (Waveform Output)
Maximum output voltage: &15V/no load, *7V/5OQ load

Output impedance: 50R
Recommended load impedance: 5OQ or more

OUTPUT CONSIDERATIONS

All logic outputs are driven by a 7400 family IC. Be care­ful not to connect a load that exceeds the drive capability
of this TTL IC. Also, do not use excessively long connect­ing cables; the resulting capacitance may have detrimen­tal effects on the output signals.

The interconnection between the Model 3930A Wave­form Synthesizer (master), and the Model 3933A Phase

3-3