Tektronix 11A32 Assembly instructions

User Reference
Manual
11A32
Two Channel
Amplifier
PROP £ 8 J Y 0 F
^ Eleclrjo Rent
Corporal icn

User Reference
Supplement
Part No. 070-5922-01
Product Group 47
11A32
Serial Number__
Please check for CHANGE INFORMATION at the rear of this manual.
Second Edition SEP 1988

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 sequen¬
tially 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 Sony/Tektronix, Japan
700000 Tektronix Holland, NV, Heerenveen, The Netherlands
Copyright© Tektronix, Inc., 1987-1988. All rights reserved. Tektronix products are covered by U.S. and
foreign patents, issued and pending. TEKTRONIX, INC. SCOPEMOBILE and are registered
trademarks. Printed in U.S.A.

Features
Dual trace
Functions
• Up to 400 MHz bandwidth (in 11402)
• Calibrated sensitivities from 1 mV to 10 V/division
• 50 D; or 1 M£1 input impedance
• High-resolution, calibrated DC offset (0.25 division/increment, coarse; 0.025
division/increment, fine)
• Fast overdrive recovery
Signals applied to the CH 1 and CH 2 input connectors can be displayed or
removed from the display by pressing the display on/off buttons adjacent to the
input connectors.
All other 11A32 functions are controlled through the host mainframe. Such
mainframe-controlled functions are:
• Sensitivity, Coarse and Fine, over a range of 1 mV to 10 V/division.
• Vertical Offset.
• Coupling: AC, DC, or Off.
• Impedance (input termination): 50 Q. or 1 MQ.
• Bandwidth Limit: 100 MHz or 20 MHz.
• Display Polarity: normal or inverted.
• Trigger Polarity: normal or inverted.
• Combination of Display Channels: See Operating Information section of
mainframe User Reference manual.
• Combination of Trigger Channels: same as Display Channels; see Operating
Information section of mainframe User Reference manual.
11A32 User Reference Supplement
l

11
11A32 User Reference Supplement

Section 1—General Information
Contents of this Supplement. 1-1
Plug-in to Mainframe Compatibility.1-2
Initial Inspection.1-2
Operating Temperature. 1-2
Installing and Removing the 11A32.1-3
Instrument Options. 1 -5
Packaging for Shipment. 1-5
Section 2—Operating the 11A32 in 11300-series Mainframes
Display On/Off.2-1
Selecting Coupling, HF Limit, and Impedance.2-1
Other Functions.2-2
Position and Offset.2-2
HF Limit.2-3
DC Circuit Loading. 2-4
Adding Waveforms. 2-5
Overdrive Recovery.2-5
50 D Overload. 2-7
Active Probes..2-8
Probe ID.......2-8
Front-Panel Error Messages... 2-9
GPIB and RS-232-C Commands and Syntax ....... 2-10
Section 3—Operating the 11A32 in 11400-series Mainframes
Display On/Off. 3-1
Other Functions. 3-1
Vertical Offset.3-2
BW Limit. 3-2
DC Circuit Loading. 3-3
Adding and Subtracting Waveforms. 3-4
Overdrive Recovery. 3-5
50 Q Overload.3-8
Active Probes.3-8
Probe ID. 3-8
Front-Panel Error Messages.3-10
GPIB and RS-232-C Commands and Syntax. 3-11
Section 4—Specification
Performance Conditions.4-1
Electrical Characteristics.4-1
Environmental Characteristics. 4-7
Physical Characteristics.4-8
Recommended Probes. 4-8
11A32 User Reference Supplement
iii

1- 1 Installing a plug-in unit in a mainframe oscilloscope.1-4
2- 1 Location of AC coupling capacitors in plug-in amplifiers.2-4
2-2 Overdrive recovery using long (top) and short (bottom) cables
terminated in 50 Cl. Traces are offset two divisions and the
photograph is a double exposure.2-6
2- 3 Overdrive recovery using long (top) and short (bottom) cables
unterminated. Traces are offset two divisions and the
photograph is a double exposure...2-7
3- 1 Location of AC coupling capacitors in plug-in amplifiers.3-3
3-2 Overdrive recovery using short (top) and long (bottom) cables
terminated in 50 Cl. Traces are offset two divisions and the
illustration is a composite of two waveforms...3-6
3-3 Overdrive recovery using short (top) and long (bottom) cables
unterminated. Traces are offset two divisions and the
illustration is a composite of two waveforms.3-7
3- 4 Sequence of decisions used to select a new waveform in response
to probe ID button.3-9
4- 1 Dimensions of 11A32...4-9
2-1 Functions and Where They are Described.2-2
2- 2 Channel Parameter Commands (for 11300-series oscilloscopes).2-10
3- 1 Functions and Where They are Described.3-1
3- 2 Channel Parameter Commands (for 11400-series oscilloscopes).3-11
4- 1 Electrical Characteristics.4-1
4-2 Environmental Characteristics.4-7
4-3 Physical Characteristics.4-8
iv
11A32 User Reference Supplement

General Information
This Supplement to the mainframe User Reference manual and the Incoming
Inspection Procedure manual are standard accessories to the 11A32. For a list of
related manuals, see Appendix B.
Contents of this Supplement
This Supplement contains the following four sections:
Section 1—GENERAL INFORMATION, describes mainframe to plug-in unit
compatibility, explains how to install and remove the 11A32 from a mainframe,
outlines any options available for the 11A32, and gives details about packaging
for shipment.
Most 11A32 functions, and their use, are described in the Operating Information
section of the mainframe User Reference manuals. These functions are those
common to all amplifier plug-in units. Examples of common functions are offset,
sensitivity, input impedance (where selectable), coupling, and bandwidth limit.
Only functions unique to the HA32~11300-series or llA32-11400-series
combinations are explained in the following sections.
Section 2—OPERATING THE 11A32 IN 11300-SERIES MAINFRAMES, explains
how to operate those 11A32 functions not covered in the 11301 and 11302 User
Reference Manual, or the 11301A and 11302A User Reference Manual.
Section 3—OPERATING THE 11A32 IN 11400-SERIES MAINFRAMES, explains
how to operate those 11A32 functions not covered in the 11401 and 11402 User
Reference Manual.
Section 4—SPECIFICATION, gives detailed specifications of all 11A32
mainframe oscilloscope combinations.
11A32 User Reference Supplement
1-1

General Information
Plug-in to Mainframe Compatibility
The 11A32 is designed for use in the 11301,11301A, 11302, 11302A, 11401, 11402,
and future 11000-series plug-in mainframes. 11A32 bandwidth varies depending
on the host mainframe. Details about bandwidth are included in Section 4,
Specification, of this Supplement, and in the Tektronix Corporate Catalog. Refer
to the Tektronix Corporate Catalog for complete compatibility information.
Initial Inspection
This instrument was inspected mechanically and electrically before shipment,
and should meet all electrical specifications. First, inspect the 11A32 for physical
damage incurred in transit. Secondly, to verify that the instrument is functioning
properly, perform the Incoming Inspection Procedure, shipped with the instrument.
This brief procedure verifies most instrument functions and checks the internal
auto-calibration references. If you find instrument damage or deficiency, contact
your local Tektronix Field Office or representative.
The 11A32 can be operated where the ambient air temperature is between 0° and
+50° C and can be stored in ambient temperatures from -40° to +75° C. After
storage at temperatures outside the operating limits, allow the chassis to reach
operating temperature limits before applying power.
1-2 11A32 User Reference Supplement

General Information
Installing and Removing the 11A32
i CAUTION i
A/wvwwwwo
To avoid instrument damage set the mainframe ON/STANDBY switch
to STANDBY before installing or removing the 12A32.
If the green indicator light remains ON, when the STANDBY position
is selected , the switch has been internally disabled.
To remove or reinstall plug-in units, use the mainframe PRINCIPAL
POWER SWITCH (rear panel) to shut OFF the power. This will
prevent damage to either the plug-in or the mainframe.
To once again enable the ON/STANDBY switch, refer the instrument
to qualified service personnel.
When installed in any 11401 or 11402 plug-in compartment, or in the 11301,
11301 A, 11302, or 11302Aleft or center plug-in compartment, the 11A32 will
provide a conventional display.
When installed in the center or right plug-in compartment of the 11301,11301A,
11302, or 11302A, the 11A32 will also provide the X (horizontal) part of an-X-Y
display, or provide a trigger signal for the mainframe time base.
To install the 11A32 in any 11000-series oscilloscope mainframe, set the
mainframe ON/STANDBY switch to STANDBY. Align the grooves in the top
and bottom of the 11A32 with the guides in the mainframe plug-in
compartment, then insert the 11A32 into the mainframe until its front panel is
flush with the front panel of the mainframe.
To remove the 11 A32 from a mainframe, set the mainframe ON-STANDBY
switch to STANDBY. Then pull the release latch (see Figure 1-1) to disengage the
unit from the mainframe, and pull the 11A32 straight out of the plug-in
compartment.
11A32 User Reference Supplement
1-3

General Information
1-4
11A32 User Reference Supplement

General Information
Instrument Options
Option 22 includes two P6134 probes.
Packaging for Shipment
If this instrument is to be shipped by commercial transportation, we recommend
that it be packaged in the original manner. The original carton and packaging
material should be saved and reused for this purpose.
NOTE
Package and ship plug-in units and mainframes separately .
If the 11A32 is to be shipped to a Tektronix Service Center for service or repair,
attach a tag to the instrument. On the tag, include the following information:
• Name and address of the instrument owner;
• Name of a person at your firm who can be contacted about the instrument;
• Complete instrument type and serial number; and
• A description of the service required.
If the original package is not available or is not fit for use, package the 11A32 as
follows:
1. Obtain a corrugated cardboard carton with inside dimensions at least six
inches greater than the instrument dimensions. Use a carton with a test
strength of at least 200 pounds.
2. Fully wrap the 11A32 with anti-static sheeting, or its equivalent, to protect
the finish.
3. Cushion the 11A32 on all sides by tightly packing dunnage or urethane
foam between the carton and the instrument. Allow three inches of packing
on each side.
4. Seal the carton with shipping tape or with industrial staples.
5. Mark the address of the Tektronix Service Center and your return address
on the carton in one or more prominent places.
11A32 User Reference Supplement
1-5

General Information

Operating the 11A32 in
11300-series Mainframes
Display On/Off
The 11A32 has only two front-panel controls—the display on/off buttons.
Pressing a display on/off button will cause its channel, and signal, to be
displayed or removed from the display (the function toggles). When a channel is
displayed, its label (CH 1 or CH 2) will be lighted.
To select the desired setting for Coupling, HF Limit, or Impedance, proceed as
follows:
la. If no trace is displayed, press any plug-in display on/off button to create a
trace.
lb. If several traces are displayed, select a channel by touching the desired
trace description at the top of the CRT.
2. On the 11301 and 11302 oscilloscopes press any VERTICAL button once—
OFFSET, SIZE, or POS. On the 11301A and 11302A oscilloscopes press any
VERTICAL button twice. This will cause the Control Menu to be displayed.
3. Touch the desired function's label. Successive touches will change its state.
11A32 User Reference Supplement
2-1

Operating the 11A32 in 11300-series mainframes
Other 11A32 functions are controlled within the 11300-series mainframe, and
their operation is described in detail in Section 2, Operating Information, of the
17301 and 11302 User Reference Manual, and the 11301A and 11302A User Reference
Manual. Table 2-1 shows where to find information about operating the 11A32.
TABLE 2-1
Functions and Where They axe Described
Function Described Under Heading
Offset,
Waveform Acquisition: Vertical Menu;
Size (V/div)
or for X-Y Display: Horizontal Menu.
Display ±Ch 1, ±Ch 2 Waveform Acquisition: Vertical Menu.
Polarity
Waveform Acquisition: Waveform Menu.
Trigger Selection Trigger Source Major Menu and Polarity
All 11300-series oscilloscopes assign position control to the Left Control knob by
pressing the VERTICAL POSition button once. The Vertical Position control
moves the trace as a user convenience. For example, when displaying multiple
channels it may be desirable to set ground references for each trace on separate
graticule lines. Position is a screen-related function; its units are divisions.
The offset function, accessed by pressing the VERTICAL OFFSET button,
subtracts a precision voltage from the input signal. Changing offset moves the
trace just as does the position control. However, if the deflection factor is
subsequently changed, the effect is different.
Changing the sensitivity will increase or decrease the size of the display around
some screen level (e.g., two divisions above graticule center) set by the Position
control. When using a sensitivity that makes the displayed waveform larger than
the screen, the Offset control is used to bring the waveform area of interest to the
screen location established by the Position control.
2-2 11A32 User Reference Supplement

Operating the 11A32 in 11300-series mainframes
The Position control has a range of plus and minus four divisions from graticule
center, but the Offset control has a range defined in volts. Offset can be as much
as 1000 divisions at 1 mV/division. The Offset control range is one volt for all
sensitivities from 1 mV to 99.5 mV/division, but increases to 10 volts for
sensitivities from 100 mV to 995 mV/division. For sensitivities from 1 volt to 10
volts/division. Offset control range increases to 100 volts.
The 11A32 attempts to maintain the user-selected offset voltage even though the
offset range changes due to a change in sensitivity. An offset voltage of less than
one volt will be maintained as the sensitivity is changed over the entire range of
1 mV/division to 10 V/division. A selected offset of greater than one volt is
beyond the offset range for the most sensitive settings and will be reset to one
volt when the sensitivity is increased to any value between 99.5 mV and
1 mV/division.
HF Limit
Two four-pole (24 dB/octave) bandwidth limit (low-pass) filters are available for
each 11A32 channel. The purpose of these filters is to reduce the amplitude of
unwanted noise or interference occurring at frequencies above the frequency of
the signal of interest. The user has a choice of cut-off (-3 dB) frequencies, either
20 MHz or 100 MHz, independently for each channel. The trigger, auxiliary
trigger, and display signal bandwidths for a channel are always the same. The
auxiliary trigger is the signal sent to the right plug-in compartment.
11A32 User Reference Supplement
2-3

Operating the 11A32 in 11300-series mainframes
AC coupling capacitors are connected differently in the 11A52 and 11A71 than in
the 11A32 and 11A34. Figure 2-1 shows this difference.
Figure 2-1. Location of AC coupling capacitors in plug-in amplifiers.
In the 11A52 and 11A71, the coupling capacitor isolates both the input
termination and the amplifier from external DC voltages. However, the coupling
capacitor in the 11A32 and 11A34 does not.
Always use caution when working with voltages in excess of 25 volts.
When 50 D. Impedance mode is selected and input coupling is set to
AC or DC, a 50 Q termination resistance is connected directly from
the 1IA32 input connector to ground. Take care that the circuit
connected to the 11A32 input will not be damaged by the 50 Q. load.
Switching from 1 MQ. to 50 Q Impedance mode when more than 25
VDC is present at the 11A32 input will exceed the peak input voltage
specification and may damage the 11A32 input relay. A damaged relay
could cause an error in calibration.
2-4
11A32 User Reference Supplement

Operating the 11A32 in 11300-series mainframes
Adding Waveforms
NOTE
Before adding waveforms, check that each channel's display is
independently on screen.
The 11300-series oscilloscopes allow the addition of any two channels. That is,
one channel may be added to a channel from another plug-in unit. A simple
restriction applies. Each channel must be in its linear operating range. This is
assured if each channel separately is within the screen area before addition.
Those portions of a trace which are off screen will not be valid when brought
back on screen using another channel's input signal or Offset control. This
general restriction applies to any dual-channel oscilloscope.
Overdrive occurs when any 11A32 channel is driven out of its linear range of
approximately ±15 divisions.
The 11A32 has extraordinarily good overdrive recovery, and this feature may be
used to greatly extend measurement resolution. For example, suppose a signal
changes from -1.7 V to +0.8 V in 1 ns. The 11A32 could be used to determine if
the signal stabilized immediately at +0.8 V or if perhaps had some small
aberration following the transition. By setting the 11A32 offset to +0.8 V and the
sensitivity to 1 mV/division, aberrations of just 0.1% of the original transition
will be 2.5 divisions in amplitude (0.1% of 2.5 V is 2.5 mV or 2.5 divisions at 1
mV/division).
Any amplifier will ultimately reach an equilibrium value after an input step
(although its accuracy will determine how far that equilibrium value is from the
correct value). The HA32 / s ability to settle quickly to within a veiy small
fraction of its equilibrium value is exceptional. The time it takes the 11A32 to
settle to within a stated fraction of the equilibrium value is its overdrive
recovery time.
Measuring the overdrive recovery time of an 11A32 takes some care and can
lead to some surprising results. An interesting experiment is to use a very flat
pulse generator, such as the Tektronix PG 506, to pulse the 11A32. Connect the
generator's fast-rise output to the 11A32 input through a short (one foot or less)
coaxial cable and select 50 Q, input impedance. Adjust the pulse amplitude to 1
volt. Set the 11A32 sensitivity to 1 mV/division. Each division now represents
0.1% of the input signal. Trigger the oscilloscope and observe the recovery of the
11A32 using 50 ns/division sweep rate. Now increase the cable length by about
three feet (for example, use a 42-inch length of RG-58 cable, Tektronix part 012-
0057-01) and observe the new waveform. See Figure 2-2.
11A32 User Reference Supplement
2-5

Operating the 11A32 in 11300 -series mainframes
Figure 2-2. Overdrive recovery using long (top) and short (bottom) cables
terminated in 50 Q. Traces are offset two divisions and the photograph is a double
exposure.
The waveform change is due to skin effect loss in the longer cable. What is
surprising is that the skin effect loss persists for over 200 ns even though the
total cable delay is only 5 ns. At 400 ns the loss is still 0.02%.
This experiment shows the importance of using a short cable to test overdrive
recovery.
A second surprise is that skin effect loss disappears almost completely (after two
cable delays) when one end is unterminated.
To observe this, use the short cable again, and select 1 MQ input impedance on
the 11A32. Insert a 2X attenuator between the cable and the pulse generator to
improve the reverse termination and to provide the same amplitude signal as
before. Observe the response and change cables again. Even at 0.1% per division
the skin effect loss is hard to detect without the forward termination. The reason
for this is that the skin effect loss is an increase in the effective series resistance
of the cable. Without current, the cable develops no series voltage drop. See
Figure 2-3.
2-6
11A32 User Reference Supplement