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ARMY TM 11-6625-2925-10
AIR FORCE TO 33A1-10-242-1
OPERATOR'S MANUAL
FOR
DUAL TIME BASE,
TEKTRONIX MODEL 7B92A
(NSN 6625-01-027-0265)
DEPARTMENTS OF THE ARMY AND THE AIR FORCE
12 MARCH 1980
TM 11-6625-2925-1 O/TO 33A1-10-242-1
WARNING
DANGEROUS VOLTAGES EXIST IN THIS EQUIPMENT
Dangerous potentials exist at several points throughout this equipment.
When the equipment is operated with the covers removed; DO NOT touch exposed connections or
components. Some transistors have voltages present on their cases. Disconnect power before cleaning
the equipment or replacing parts.
DON'T TAKE CHANCES!
TM 11-6625-2925-1 O/TO 33A1-10-242-1
Copyright 1974 (new material 1975) by Tektronix Inc. All rights reserved.
REPROD UCED B Y PERMISSION OF THE COP YRIGHT O WNER, TEKTRONIX INC.
TM 11-6625-2925-10
TO 33A1-10-242-1
Technical Manual DEPARTMENTS OF THE ARMY
No. 11-6625-2925-10 AND THE AIR FORCE
Technical Order
TO 33A1-10-242-1 Washington, DC, 12 March 1980
OPERATOR'S MANUAL
FOR
DUAL TIME BASE, TEKTRONIX MODEL 7B92A
(NSN 6625-01-027-0265)
REPORTING OF ERRORS
You can improve this manual by recommending improvements using DA Form 2028-2 located in the
back of the manual. Simply tear out the self-addressed form, fill it out as shown on the sample fold it
where shown, and drop it in the mail.
If there are no blank DA Forms 2028-2 in the back of your manual, use the standard DA Form 2028
(Recommended Changes to Publications and Blank Forms) and forward to the Commander, US Army
Communications and Electronics Materiel Readiness Command, ATTN: DRSEL-ME-MQ, Fort
Monmouth, NJ 07703.
For Air Force, use USAFLC Form 252 (Request for TO Revision or Change). Forward direct to prime
ALC/MST.
In either case, a reply will be furnished direct to you.
Page
SECTION 0 INTRODUCTION
Scope 0-1
Indexes of Publications 0-1
Reporting Equipment Improvement Recommendations (EIR) 0-1
Administrative Storage 0-1
Destruction of Army Electronics Materiel 0-1
i
TM 11-6625-2925-10/T0 33A1-10-242-1
PAGE
SECTION I. SPECIFICATION 1-1
Electrical Characteristics 1-1
Environmental 1-5
Physical 1-5
SECTION II. OPERATING INSTRUCTIONS 2-1
Installation 2-1
Front-Panel Controls, Connectors, and Indicators 2-2
Main Triggering Controls 2-2
Sweep Controls 2-4
Delayed Triggering Controls 2-4
Front-Panel Inputs 2-5
Familiarization Procedure 2-5
Setup Procedure 2-5
Sweep Functions 2-6
Triggering Functions 2-6
General Operating Information 2-8
Main Triggering 2-8
Main Trigger Modes 2-8
Main Trigger Coupling 2-8
Main Trigger Source 2-9
Input Impedance 2-9
Trigger Slope 2-9
Trigger Level 2-11
Selecting Sweep Rates 2-11
Time Measurement 2-11
Display Modes 2-11
Delay Time Multiplier 2-12
Delayed Sweep Triggering 2-12
Mainframe Operating Modes 2-13
Applications 2-13
Time Duration Measurements 2-13
Determining Frequency 2-13
Risetime Measurements 2-14
Delayed Sweep Measurements 2-14
Delayed Sweep Magnification 2-15
Triggered Delayed Sweep Magnification 2-16
Displaying Complex Signals Using Delayed Sweep 2-16
Pulse Jitter Measurements 2-17
Appendix A References A-1
A-1
TM 11-6625-2925-10/T0 33Al-10-242-1
LIST OF ILLUSTRATIONS
FIGURE NO. PAGE
1-1 7B92A Dual Time Base. v
2-1 Location of Variable and Mainframe Selector multi-pin 2-1
connectors.
2-2 Location of release latch. 2-2
2-3 Front panel controls and connectors. 2-3
2-4 Effect of LEVEL control and SLOPE switch on CRT display. 2-10
2-5 Area of graticule used for most accurate time measurements. 2-11
2-6 Typical alternate sweep display. 2-12
2-7 Measuring the time duration between points on a waveform. 2-13
2-8 Measuring risetime. 2-14
2-9 Measuring time difference using delayed sweep. 2-15
2-10 Using delayed sweep for magnification 2-16
2-11 Displaying a complex signal using delayed sweep. 2-17
2-12 Measuring pulse jitter. 2-18
iii
TM 11-6625-2925-10/T0 33A1-10-242-1
LIST OF TABLES
TABLE NO. PAGE
1-1 Electrical Characteristics 1-1
1-2 Environmental 1-5
1-3 Physical 1-5
2-1 Risetime Measurements 2-14
iv
TM 11-6625-2925-10/T0 33A1-10-242-1
Figure 1-1. 7B91A Dual Time Base
v
TM I 11-6625-2925-1 OITO 33A1-1 0-242-1
SECTION 0
INTRODUCTION
0-1. Scope
This manual contains instructions for the operation of Dual Time Base, Tektronix Model 7B92A. Throughout this manual
Dual Time Base, Tektronix Model 7B92A is referred to as the 7B92A.
0-2. Indexes of Publications
a. DA Pam 310-4. Refer to the latest issue of DA Pam 310-4 to determine whether there are new editions,
changes, or additional publications pertaining to the equipment.
b. DA Pam 310-7. Refer to DA Pam 310-7 to determine whether there are modification work orders (MWO's)
pertaining to the equipment.
0-3. Maintenance Forms, Records, and Reports
a. Reports of Maintenance and Unsatisfactory Equipment. Maintenance forms, records, and reports which are
to be used by maintenance personnel at all maintenance levels are listed in and prescribed by TM 38-750 (Army). Air
Force personnel will use AFM 66-1 for maintenance reporting and TO-00-35D54 for unsatisfactory equipment reporting.
b. Report of Packaging and Handling Deficiencies. Fill out and forward DD Form 6 (Packaging Improvement
Report) as prescribed in AR700-58/NAVSUPiNST 4030.29/AFR 71-13/MCO P4030.29A, and DLAR 4145.8.
c. Discrepancy in Shipment Report (DISREP) (SF 361). Fill out and forward Discrepancy in Shipment Report
(DISREP) (SF 361) as prescribed in AR 55-38/NAVSUPINST 4610.33B/AFR 75-18/MCO P4610.19C and DLR 4500.15.
0-4. Reporting Equipment Improvement Recommendations (EIR)
a. Army. EIR's will be prepared using Standard Form 368, Quality Deficiency Report. Instructions for preparing
EIR's are provided in TM38-750, The Army Maintenance Management System. EIR's should be mailed direct to
Commander, US Army Communications and Electronics Materiel Readiness Command, ATTN: DRSEL-ME-MQ, Fort
Monmouth, NJ 07703. A reply will be furnished direct to you.
b. Air Force. Air Force personnel are encourage to submit EIR's in accordance with AFM 900-4.
0-5. Administrative Storage
To prepare Dual Time, Base, Tektronix Model 7B92A for administrative storage, perform the procedures described in this
manual, pages 2-5 through 2-7, titled: Setup Procedure, Sweep Functions, and Triggering Functions. To remove the
7B92A from administrative storage repeat the Setup Procedure Sweep Functions, and Triggering Functions to determine
that the equipment is fully operational.
0-6. Destruction of Army Electronics Materiel
Destruction of Army electronics materiel to prevent enemy use shall be in accordance with TM 750-244-2.
0-1
TM 11-6625-2925-10/T0 33A1-10-242-1
SECTION I
SPECIFICATION
This instrument will meet the electrical characteristics listed under Performance Requirement in Table 1-1, following com-
plete calibration. The following electrical characteristics apply over an ambient temperature range of OOC to +500C,
except as otherwise indicated. Warm-up time for given accuracy is 20 minutes.
TABLE 1-1
Electrical Characteristics
1-1
TM 11-6625-2925-10/T0 33A1-10-242-1
TABLE 1-1 (cont.)
Electrical Characteristics
4
The specified -3 dB frequency of the Vertical System replaces any frequencies in the above table when the number in the
table is greater than the -3 dB frequency of the Vertical System.
1-2 REV. A, APR. 1975
TM 11-6625-2925-10/TO 33A1-10-242-1
TABLE 1-1 (cont.)
Electrical Characteristics
REV. A, NOV. 1975 1-3
TM 11-6625-2925-10o/T0 33A1-10-242-1
REV. B, NOV. 1975
1-4
M 11-6625-2925-10/T0 33A1-10-242-1
TABLE 1-2 TABLE 1-3
Environmental Physical
Refer to the Specification for the associated Net Weight 3.062 lbs (1.372 Kg)
oscilloscope. Dimensions See figure 1-2, Dimensional
Drawing
Figure 1-2. Dimensional drawing.
1-5
TM 11-6625-2925-10/T0 33Al-10-242-1
SECTION II
OPERATING INSTRUCTIONS
The 7B92A Dual Time-Base Plug-In Unit operates with a Tektronix 7000-Series Oscilloscope and a 7A-Series Amplifier
plug-in unit to form a complete high-frequency oscilloscope system. This section describes the operation of the front-panel
controls and connectors, provides general operating information, an Operating Check-Out procedure, and basic
applications for this instrument.
NOTE
The AL T OFF position, which allows the Intensified mode of operation, is applicable to instruments SN
B060000 and up.
INSTALLATION NOTE
The 7B92A is designed to operate in the horizontal plug- The 7B71 will not delay the 7892A for
in compartment of the oscilloscope. This instrument can displaying alternating Delaying and
also be installed in a vertical plug-in compartment to Delayed sweeps. Instead, it causes a
provide a vertical sweep on the CRT. However, when sweep lock-up to occur under the
used in this manner, there are no internal triggering or following conditions; with the 7B71 in the
retrace blanking provisions, and the unit may not meet A Horizontal compartment, and the
the specifications given in Section 1. 7B92A in the B Horizontal compartment,
the sweep locks up if the 7B92A is in its
Before proceeding with installation, check the settings of Alternate mode and the Mainframe
the Time/Div Variable Selector multi-pin connector and Horizontal Mode is Alt. Lock-up can be
the Mainframe Selector multi-pin connector (see figure 2- avoided by changing the Mainframe
1). Horizontal Mode to Chop or B. This
allows both 7892A sweeps to be
The Time/Div Variable Selector determines whether the displayed.
front-panel Time/Div VARIABLE control operates in
conjunction with the delaying or delayed sweeps. The To install the 7B92A in a plug-in compartment, push it in
Mainframe Selector adapts the 7B92A to the until it fits firmly into the compartment. The front panel of
oscilloscope mainframe being used. The two mainframe the 7B92A should be flush with the front panel of the
selections are: oscilloscope. Even though the gain of the oscilloscope is
standardized, the sweep calibration of the 7B92A should
(1) 7800 and 7900-Series Oscilloscopes. be checked when installed. The procedure for checking
the unit is given under Sweep Calibration in the
(2) All other 7000-Series Oscilloscopes. Operating Checkout procedure in this section.
Figure 2-1. Location of Variable and Mainframe Selector multi-pin connectors.
REV. B, NOV. 1975 2-1
TM 11-6625-2925-1O/T0 33A1-10-242-1
To remove the 7B92A, pull the release latch (see figure 2-2) to (2) SLOPE Switch
disengage the unit from the oscilloscope, and pull it out of the Permits triggering on the positive or negative slope of the
plug-in compartment. trigger signal (except in HF SYNC).
(3) TRIG'D Indicator
FRONT-PANEL CONTROLS, When lit, indicates that the sweep is triggered and will
CONNECTORS, AND INDICATORS produce a display with correct setting of the POSITION
control and the controls on the associated Amplifier plug-
All controls, connectors, and indicators required for the in unit(s) and oscilloscope.
operation of the 7B92A, except the Time/Div Variable and
Mainframe Selectors, are located on the front panel. A brief (4) MODE Switches
description of the front panel controls, connectors, and Select the desired main triggering mode. Selected mode
indicators is given here. More detailed information is given is indicated by lighted pushbutton.
under General Operating Information. figure 21 shows the
Time/Div Variable and Mainframe Selectors. figure 23 shows AUTO: Selects a triggered sweep initiated by the applied
the front panel controls, connectors, and indicators. trigger signal at a point determined by the LEVEL control
and SLOPE switch when the trigger signal repetition rate
Main Triggering Controls is above 30 hertz and within the frequency range selected
by the COUPLING switches. When the LEVEL control is
(1) LEVEL Control outside the amplitude range, the trigger repetition rate is
outside the frequency range selected by the COUPLING
Selects amplitude point on trigger signal where sweep switches, or the trigger signal is inadequate, the sweep
triggering occurs when the Main Triggering Mode AUTO, free-runs to provide a reference trace.
NORM, or SINGLE SWEEP switches are pressed. When
the Main Triggering Mode HF SYNC switch is pressed, the HF SYNC: Sweep initiated by trigger signals with
LEVEL control adjusts the frequency of the trigger repetition rates above 100 megahertz and within the range
generator to synchronize with the frequency (or selected by the COUPLING switch. Stable display can be
subharmonic) of the triggering signal to provide a stable obtained when the LEVEL control adjusts the frequency of
display. the trigger generator to the frequency (or subharmonic) of
the trigger signal. When the LEVEL control is adjusted to
frequencies between subharmonics, the sweep free-runs.
NORM: Sweep initiated by the applied trigger signal at a
point selected by the LEVEL control and SLOPE switch
over the frequency range selected by the COUPLI NG
switches. Triggered sweep can be obtained only over the
amplitude range of the applied trigger signal. When the
LEVEL control is either outside the amplitude range, the
trigger repetition rate is outside the frequency range
selected by the COUPLING switches, or the trigger signal
is inadequate, there is no trace.
SINGLE SWEEP-RESET: When the SINGLE
SWEEPRESET pushbutton switch is pressed, a single
trace will be presented when the next trigger pulse is
received. The SINGLE SWEEP-RESET pushbutton
remains lit until a trigger is received and the sweep is
completed. The SINGLE SWEEP-RESET pushbutton
switch must be pressed again before another sweep can
be displayed.
(5) COUPLING Switches Select trigger signal coupling.
Selected coupling is indicated by lighted pushbutton.
Figure 2-2. Location of release latch.
2-2 REV. B, NOV. 1975
TM 11-6625-2925-1O/T0 33A1-10-242-1
AC: Rejects dc and attenuates ac signals below (6) SOURCE Switches
approximately 30 hertz. Accepts signals between 30 hertz and Select the triggering source. Selected source is indicated
500 megahertz. by lighted pushbutton.
AC LF REJ: Rejects dc and attenuates signals below 30 INT: Trigger signal obtained internally from Amplifier plug-
kilohertz. Accepts signals between 30 kilohertz and 500 in unit of oscilloscope.
megahertz.
LINE: Trigger signal obtained internally from the line
AC HF REJ: Rejects dc and attenuates signals above 50 voltage applied to the oscilloscope.
kilohertz. Accepts signals from 30 hertz to 50 kilohertz.
EXT: Trigger signal obtained from an external source
DC: Accepts all signals from dc to 500 megahertz. applied to the MAIN TRIG IN connector.
Figure 2-3. Front-panel controls and connectors
REV. A, NOV. 1975 2-3
TM 11-6625-2925-10/TO 33A1-10-242-1
(6) SOURCE Switches (cont.) (9) VARIABLE
EXT + 10: Trigger signal obtained from an external source Two-position switch actuated by the VARIABLE control to
applied to the MAIN TRIG IN connector. In this position, the select calibrated or uncalibrated sweep rates. In the CAL
external signal is attenuated before it is applied to the trigger position (knob in) the VARIABLE control is inoperative and the
circuit. sweep rate is calibrated. When pressed and released, the
knob moves out to activate the VARIABLE control for
Sweep Controls uncalibrated sweep rates. The sweep rate in each TIME/DIV
switch position can be reduced to at least the sweep rate of
(7) TIME/DIV OR DL.Y TIME the next slower position. The VARIABLE control will operate
Selects the basic sweep rate for normal sweep operation and with either the delaying or delayed sweep by means of the
selects the delay time (multiplied by the DELAY TIME MULT internal Time/Div Variable Selector.
dial setting) when operating in the Alternate or Delayed sweep
modes. The VARIABLE control must be in the CAL (knob in) (10) POSITION
position for calibrated sweep rate. Control Positions the display horizontally on the graticule.
(8) DLY'D Time/Division (11) CONTRAST
Selects the delayed sweep rate for operation in Delayed and Control Varies the relative brightness of the intensified portion
Alternate sweep modes. The VARIABLE control must be in of the delaying trace when in the Alternate mode.
the CAL (knob in) position for calibrated sweep rate.
(12) TRACE SEP/ALT OFF
Four display modes can be selected by the following switch Control This control vertically positions the delaying sweep
settings: display up to 3.5 divisions above the delayed sweep display
Normal Sweep: A normal sweep is selected when the when in the Alternate mode. The ALT OFF position allows the
TIME/DIV OR DLY TIME switch and the DLY'D Time/Division Intensified sweep mode of operation, permitting the display of
switches are locked together at the same sweep rate. The an intensified portion of the delaying sweep.
DLY'D Time/Division knob must be pressed in for normal
sweep mode. Calibrated sweep rates from 0.2 second/division (13) INTENSITY
to 0.5 nanosecond/division can be selected. Control Varies the intensity of the Intensified sweep only when
operating in the INTENS or ALT mode.
ALT Sweep: The Alternate mode is selected when the DLY'D
Time/Division switch is pulled out and rotated clockwise and (14) SWP CAL
the ']-TRACE SEP control is turned clockwise from the ALT Adjustment Screwdriver adjustment sets the basic timing of
OFF position. In this mode, the delaying sweep is displayed the 7B92A to compensate for slight differences in input
(with an intensified zone during the time that the delayed sensitivity when changing indicator oscilloscopes.
sweep runs) alternately with the delayed sweep..
(15) DELAY TIME MULT
Intensified Sweep: The intensified sweep mode (Intens) is Dial Provides variable delay of 0 to 9.8 times the basic delay
selected when the DLY'D Time/Division switch is pulled out, time selected by the TIME/DIV OR DLY TIME switch.
and rotated to the desired sweep rate faster than the TIME/DIV
or DLY TIME switch setting, and the TRACE SEP control is Delayed Triggering Controls
rotated counterclockwise to the ALT OFF position (see figure2-
3). In this mode, a portion of the delaying sweep is intensified (16) LEVEL Control
during the time that the delayed sweep generator runs. Determines the delayed trigger mode and the delayed trigger
level.
DLY'D Sweep: The delayed sweep mode is selected when the
DLY'D Time/Division switch is pulled out, rotated for the RUNS AFTER DELAY TIME (LEVEL control turned fully
desired delayed sweep rate, and then pushed in. In this clockwise into detent): Delayed sweep runs immediately
mode, the delayed sweep is displayed at a rate determined by following the delay time selected by the TIME/DIV OR DLY
the DLY'D Time/Division switch at the end of each delay TIME switch and the DELAY TIME MULT dial. Delayed
period, as selected by the TIME/[)IV OR DLY TIME switch and SLOPE, COUPLING, and SOURCE functions are inoperative.
the DELAY TIME MULT dial setting.
Delayed Sweep Triggerable: When the Delayed Triggering
LEVEL control is turned counter-clockwise out of detent, the
delayed sweep is triggerable. The Delayed Triggering
2-4 REV. B, NOV. 1975
TM 11-6625-2925-10/TO 33A1-10-242-1
(16) LEVEL Control (cont.)
(22) DLY'D TRIG IN Connector
LEVEL control can now be rotated to select the Serves as an external trigger input for the delayed trig-
amplitude point on the trigger signal at which the delayed gering circuit when the Delayed Triggering SOURCE
sweep is triggered. In the Delayed Sweep Triggerable switch is set to EXT.
mode, the delayed SLOPE, COUPLING, and SOURCE
functions are activated. CAUTION
(17) SLOPE Switch Do not exceed 7 volts (rms) of external
Two-position switch to select the slope of the trigger signal when 50 termination is selected.
signal which starts the delayed sweep.
+ : The delayed sweep can be triggered on the positive FAMILIARIZATION PROCEDURE
slope of the trigger signal.
The following procedure may be used for familiarization or as
-: The delayed sweep can be triggered on the negative a check of basic instrument operation. The procedure is
slope of the trigger signal. divided into two parts, Sweep Functions and Triggering
Functions. A complete operating check of the 7B92A
functions can be made by performing both parts, or each part
(18) SOURCE Switch may be performed separately. If performing the
Two-position pushbutton switch to select the source of the Familiarization Procedure reveals a malfunction or improper
delayed trigger signal. calibration, first check the operation of the associated plug-in
units; then refer to the 7B92A Service manual.
IINT: The delayed trigger signal is obtained from the
vertical amplifier of the oscilloscope.
NOTE
EXT: The delayed trigger signal is obtained from an
external source connected to the DLY'D TRIG IN For optimum high-frequency performance,
connector. the 7B92A should be installed in an
oscilloscope system with similar frequency
(19) COUPLING Switch and sweep-rate capabilities.
Two-position pushbutton switch to determine the method
of coupling the trigger signal to the delayed trigger circuit. Setup Procedure
1. Install the 7B92A in a horizontal compartment of the
AC: Rejects dc and attenuates signals below 30 hertz. oscilloscope.
Accepts trigger signals from 30 hertz to 500 megahertz.
2. Install the Amplifier plug-in unit in a vertical compartment.
DC: Accepts trigger signals from dc to 500 megahertz.
3. Turn on the oscilloscope and allow at least 20 minutes
warm-up.
Front-Panel Inputs 4. Set the 7B92A controls as follows:
(20) MAIN TRIG IN Connector Main Triggering
Serves as an external trigger input for the main trigger-ing SLOPE (+)
circuit when the Main Triggering Source EXT or EXT