Tektronix 7B92A User manual

°
Tektronix, Inc .
P.O
. Box 500
Beaverton, Oregon

97077
COMMITl"ED TO
EXCELLENCE
RLSASS
~HE K
F'4R HANGS
IN~~R ATION
AT THE
REAR ~~'
THIS MANUAL
.
I N

TF~ U ~T I Q
N

M

loJ,~ L
Serial Number __ ._
070-1751-02

First Printing
JUN 1978
Product
Group 42

Revised
JUN 1987

LIST
OF ILLUSTRATIONS
............  ,.. 

iii
SAFETY
SUMMARY . . . ..................................
.

v
Page
SECTION
1

OPERATING
INSTRUCTIONS
INTRODUCTION
..........................
...... . .
. . . . . . 1-1
INSTALLATION ........................ .
. ...... .... .... 1-1
FRONT-PANEL
CONTROLS,
CONNECTORS, AND
INDICATORS .....

1-2
Main Triggering Controls ......................,.....,,, ,

1-2
Sweep Controls . . . . ..............................,,,. ,

1-4
Delayed Triggering Controls
..........................,, 1-5
Front-Panel I nputs

..........................,,.,,,,,, , ,

1-5
FUNCTIONAL CHECK .............................,.. . . . .

1-5
Setup Procedure ......................... ....  ,
1-6
Sweep Functions .........................     ,

1-6
Triggering
Functions ...................... ...... ... .., ,

1-7
GENERAL OPERATING
INFORMATION .......... . . . ... . . ... . .

1-8
Main Triggering .........................
... . . . . ..... . .

1-8
Main Trigger Modes ..................... . . . . . ...... ,,.,

1-8
Main Trigger Coupling ..............,... . . .   ,.,.  ,

1-9
Main Trigger
Source

................... ... .  , ... 

1-10
Input
Impedance ...................... ... .... .... .  . ,

1-10
Trigger Slope

.......................
... ....... . . .....

1-10
Trigger Level .......................
... ...... .... .....

1-10
Selecting Sweep Rates ................ . . ............,,,.

1-12
TimeMeasurement

.................. . .  .,.  ... 

1-12
Display Modes

.................
. . . . ..................

1-12
Delay
Time Multiplier ......... . . . ... ........,. 

1-13
Delayed Sweep Triggering

. .... ..... . . ...........,,,,,.,,

1-13
SECTION 2

SPECIFICATION ........ ... ...........,..  , .  . 

2-1
WARNING
THE FOLLOWING SERVICING INSTRUCTIONS
AREFOR USE BY QUALIFIED PER-
SONNEL ONLY . T O AVOID PERSONAL INJURY,
DO
NOT PERFORM
ANY SERVICING
OTHER THAN THAT
CONTAINED IN OPERATING INSTRUCTIONS
UNLESS YOUARE
QUALIFIED TO DOSO .
SECTION 3

THEORY OF OPERATION
Block Diagram Description ................ .......,..,,,,. . .
3-1
Detailed Circuit Description .............. ................ , ,

3-1
Main Trigger Generator ............... ............... ,,,

3-1
Delaying Sweep Generator ............. ....... . . ..... ....

3-3
Delayed Trigger Generator ............. ....... . . .,,,, .,.
3-4
Delayed
Sweep Generator

............ ........ , . ,,,,. .,,,

3-6
Horizontal Logic ................. . . ..... . . . . . ..... ...,
3-6
Output Amplifier

................
. . . .... . . .... .... .....

3-7
Readout . .
. . . .........................
..............
3-7

SECTION 4

MAINTENANCE

Page
Preventive Maintenance .................. ............. ....

4-1
Cleaning . .
.
........................
............. . . . . 4-1
Visual Inspection ...................... ............ .... 4-1
Lubrication . . . . ...................... .............. . . 4-1
Semiconductor Checks

................. ............. ...

4-2
Adjustment After Repair
................. ............. ...

4-2
Troubleshooting
. . ...................... ............. ... 4-3
Troubleshooting Aids ................... ............. ...

4-3
Troubleshooting Equipment .............. ............. ... 4-6
Troubleshooting Techniques

.............. ............. . .

4-6
Corrective Maintenance .................... ........ . .... . .

4-8
Obtaining Replacement Parts .............. ............. . .

4-8
Soldering Techniques

................... .............. .

4-8
Component Removal and Replacement ....... .............. . 4-9
Adjustment After Repair .................. ....... . ...... .

4-11
Repackaging For Shipment

............... .... . ......... .

4-11
SECTION 5

PERFORMANCE
CHECK/CALIBRATION
Preliminary Information ... . ................. . . . . . . . . ....

5-1
Test Equipment Required . ... .................... . . . . ....

5-1
Part I Performance Check

. . ... ..................... . . .....

5-4
Outline for Part I Performance Check

.................. .....

5-6
A
.
Trigger Sensitivity . ..... ... . ................... ....

5-4
B .
Horizontal System
. .... ......................... ... 5-4
Preliminary Procedure ....... ... . .................... ... 5-4
A . Trigger Sensitivity . ....... ........................ ...

5-5
B . Horizontal System . . . . .... . . ...................... ...

5-10
Part II Calibration

....... . .... . . . . ................... .... 5-16
Outline for Part
II Calibration

. . . . . . . . ................. ....

5-16
A . Trigger Sensitivity (SN 8070000-above) ............... ...

5-16
B . Trigger Sensitivity (SN ~069999-below) ................ . .

5-16
C . Horizontal System . ........... ................... . . 5-17
Preliminary Procedure . .......... ................... . .

5-17
A . Trigger
Sensitivity (SN ~070000-above) . . ................. .

5-18
B . Trigger Sensitivity (SN ~069999-below) . . ................. .

5-25
C . Horizontal System ................ .................. . 5-33
SECTION 6

OPTIONS
SECTION 7

REPLACEABLE ELECTRICAL
PARTS
SECTION 8

DIAGRAMS AND CIRCUIT BOARD ILLUSTRATIONS
SECTION 9

REPLACEABLE MECHANICAL PARTS
Change Information
TS (coot)

REV APR
1984
L .I ~°
Figure No .

Page
Frontispiece

7B92A Dual Time Base
1-1

Location of Variable and Mainframe Selector multi-pin connectors .

......

1-1
1-2

Location of release latch . . . . . . . . . . . ..........................

1-2
1-3

Front-panel controls and connectors .

...........................

1-3
1-4

Effect
of
MAIN TRIGGERING LEVEL and
SLOPE
controls
on
crt
display . . .

1-11
1-5

Area of graticule used for most accurate time measurements .

..........

1-12
1-6

Typical alternate sweep display .

. . . . ...........................

1-13
2-1

Dimensional drawing .

........ . . . ........................... 2-5
4-1

Lubrication procedure for a typical cam switch .

....................

4-2
4-2

Semiconductor lead configurations .

. . . ........................ .

4-4
4-3

Inter-board multi-pin connector assembly . ....................... .

4-5
4-4

End-lead multi-pin connector assembly .

........................ .

4-5
4-5

Location of pin numbers of Interface connector .

.................. .

4-5
5-1

Main Triggering level range . . ................................ .

5-6
5-2

Delayed Triggering level range .

.............................. . 5-6
5-3

Variable Time/Division range . .................................

5-13
5-4

Fast delay time accuracy . . ............................... . . . .

5-14
5-4A

AC
HF
REJ Balance ......... . . . ................... ..... ........ ....
5-19
5-5

DC
balance . (Circle denotes correct trigger point .) ..................

5-19
5-6

Trigger Sensitivity . (Circle denotes correct trigger point .)

.............

5-19
5-7

Main Triggering level range . (Circle denotes triggering limits .)

.........

5-19
5-8

Delayed Triggering level range . (Circle denotes triggering limits .)

.......

5-21
5-9

DC balance . (Circle denotes correct trigger point .) ... ...............

5-26
5-10

Trigger sensitivity
.
(Circle denotes correct trigger
point .)

.............

5-26
5-11

Main Triggering level range . (Circle denotes triggering limits .)

.........

5-27
5-12

Delayed Triggering level range . (Circle denotes triggering limits .)

.......

5-29
5-13

Correct DTM Scale and Delay Start adjustment (circle) .

..............

5-34
5-14

Variable Time/Division range . ................. ................

5-38
5-15

Fast delay time accuracy . .................... ................

5-39

7B92A
Figure
No .
LIST
OF
ILLUSTRATIONS
(cont)
The
illustrations
in
Section 8 are located near
their
associated diagrams on
the foldout pages .
8-1

Circuit board locations
8-2

Block diagram
8-3

A3 Coupling Switch circuit board
8-4

A5 Delayed Triggering Switch circuit board
8-5

A2 Source Switch circuit board
8-6

A4 Mode Switch circuit board
8-7

A1 External Input circuit board
8-8

A8 Main Trigger circuit board (SN 8070000-above)
8-9

A8 Main Trigger circuit board (SN 8069999-below)
8-10

A9 Delayed
Trigger
circuit board (SN B096951-above)
8-11

A9 Delayed
Trigger
circuit board (SN 870000-B096950)
8-12

A9 Delayed Trigger circuit board (SN 8069999-below)
8-13

A6 Interface circuit board (SN B095741-above)
8-14

A6
Interface circuit
board (SN
8095740-below)
8-15

A7 Logic circuit board (SN 8059999-below)
8-16

A7 Logic circuit board (SN 8060000-above)
8-17

A12 Readout circuit board
8-18

Location of Sweep Timing adjustments
8-19

Location of Main Trigger adjustments (SN 8069999-below)
8-20

Location of Delayed Trigger adjustments (SN 8069999-below)
8-21

Location of Main Trigger adjustments (SN B070000-above)
8-22

Location of Delayed Trigger adjustments (SN 8070000-above)

This manual contains safety information that the user must
follow to ensure safe operation of this
instrument . WARNING information is intended to protect
the operator ; CAUTION information
is
intended
to protect the instrument . The following are general
safety precautions that must be observed
during all phases of operation and maintenance
.
Ground the Instrument
To reduce electrical-shock
hazard, the mainframe (oscilloscope)
chassis must be properly
grounded .
Refer to the mainframe manual for grounding
information .
Do Not Operate in Explosive Atmosphere
Do not operate this instrument in an area
where flammable gases or fumes are present
. Such
operation couldcause an explosion
.
Avoid Live Circuits
Electrical-shock hazards are present in this
instrument . The protective instrument covers
must not be removed by operating
personnel . Component replacement and infernal
adjustments must be referred to qualified
service personnel .
Do
Not Service orAdjust Alone
Do
not service or make internal adjustments
to this instrument unless another person,
capable
of giving first aid and resuscitation, is
present .
Warning
Statements
Warning statements accompany potentially
dangerous procedures in this manual
. The following
warnings appear in this manual and are
listed here for additional emphasis .
To avoid
electrical shock, disconnect theinstrument from
the power source before soldering
.
To avoid electrical shock, disconnect
the instrument from the power source
before replacing
components .
Handle silicone grease
with care . Avoid getting silicone
grease in eyes . Wash hands
thoroughly
after use .

7B92A
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DUAL
TIME BASE
7B92A

OPERATING
INSTRUCTIONS
INTRODUCTION

INSTALLATION
The
7B92A Dual Time Base unit
provides normal,

The 7B92A is designed
to operate in the horizontal
delayed,
intensified, and alternate sweep operation
for

plug-in compartment of the oscilloscope . This instrument
TEKTRONIX

7000-Series

Oscilloscopes .

Calibrated

can also be installed in a vertical plug-in compartment to
sweep rates from
0 .2 second to 0 .5 nanosecond and

provide a
vertical sweep on the crt . However, when used in
triggering
to 500 megahertz are provided . The 7B92A is

this manner,
there are no internal triggering or retrace
intended for
use
with
high-frequency 7000-Series

blanking
provisions, and the unit may not meet the
Oscilloscope systems ; however,
most 7B92A functions

specifications given in the
Specification section of this
are compatible with all 7000-Series Oscilloscopes
.

manual .
Other features include lighted
pushbutton switches,

Before proceeding with installation, check the
settings
compatibility

with

indicator
oscilloscopes

having

an

of the
Time/Div Variable Selectormulti-pin
connector and
alphanumeric readout system, and 0 to 9
.8
times
con-

the Mainframe
Selector multi-pin
connector (see Fig . 1-1 ) .
tinuous
sweep delay . A VARIABLE control allows con-

The Time/Div
Variable Selector determines whether
the
tinuously
variable sweep rates between calibrated steps .

front-panel Time/Div VARIABLE
control operates in con-
Also, when operating in
the AUTO MAIN TRIGGERING

junction with the delaying or
delayed sweeps . The Main-
Mode, a bright base line
is displayed in the absence of a

frame Selector adapts the
7B92A to the oscilloscope
trigger signal .

mainframe being used . The two
mainframe selections are :
This section
describes the operation of the front-panel
controls and
connectors, and provides a functional check
and general operating information
for this instrument .
REV B, JUN 1978
NOTE
The ALT OFF position,
which allows fhe lnfensified
mode of operation, is
applicable to instruments SN
8060000-ab o ve .
1 . 7800 and
7900-Series Oscilloscopes .
2
.
All other 7000-Series Oscilloscopes
.
NO TE
The 7871 will not
delay the 7892A for displaying
alternating Delaying
and Delayed sweeps . lnsfead, it
causes a sweep lock-up to
occurunder the following
conditions ;
with the 7871 in the A
horizontal com-
Fig . 1-1 . Location of Variable
and Mainframe Selector multi-pin
connectors .
Section 1-7B92A
i~s2-oz

Operating Instructions-7B92A
To install the 7B92A in a plug-in compartment, push
it
in until it fits firmly into the compartment .
The front panel
of the 7B92A should be flush
with the front panel of the
oscilloscope . Eventhough
the gain of the oscilloscope is
standardized,
the sweep calibration of the 7B92A should
be
checked when installed . The procedure for checking
the unit is given under Sweep Calibration in the
Operating
Checkout procedure in this section .
To remove the 7B92A, pull the release latch (see
Fig .
1-2) to disengagethe unit from the oscilloscope,
and pull it
out of the plug-in compartment .
partmentandthe7B92AintheBhorizontalcompart-

shows
the Time/Div Variable and Mainframe Selectors .
meni, the sweep locks up if the 7B92A is in its

Fig . 1-3 shows the front-panel controls, connectors,
and
Alternate mode and the Mainframe
Horizontal mode

i ndicators .
i s Alf . Lock-up can be avoided by
changing the
Mainframe
Horizontal mode to Chop or B . This
allows both 7B92A
sweeps to be displayed .
RELEASE
LATCH

t X52-t s
Fig .
1-2
.
Location of release latch .
MAIN TRIGGERING Controls
LEVEL Control
Selects amplitude point on trigger signal where
sweep triggering occurs
when the MAIN
TRIGGERING MODE AUTO,
NORM,
or
SINGLE
SWEEP switches are pressed . When the MAIN
TRIGGERING MODE HF SYNC switch is pressed,
the LEVEL control adjusts the frequency of the
trigger generator to
synchronize with the frequency
(or sub-harmonic) of the
triggering signal to provide
a
stable display .
SLOPE Control
Permits triggering on the positive or
negative slope
of the trigger signal (except in HF
SYNC)
.
O
TRIG'D Indicator
When lit,
indicates that the sweep is triggered and
will produce a display with correct setting of the
POSITION control and the controls on the
associated amplifier plug-in units) and os-
cilloscope .
MODE Switches
Select the desired MAIN TRIGGERING mode .
Selected mode is indicated
by lighted pushbutton .
AUTO :
Selects a triggered sweep initiated by the
applied trigger signal at a point determined by the
LEVEL control and SLOPE control when the trigger
signal repetition rate is above30
hertz and within the
frequency
range selected by the COUPLING
switches .
When the LEVEL control is outside the
amplitude range, the trigger repetition rate is outside
the frequency range selected by the COUPLING
switches, or the trigger signal is inadequate, the
sweep free-runs to provide a reference
trace .
FRONT-PANEL CONTROLS,
CONNECTORS, AND INDICATORS

HFSYNC
:
sweep initiated by trigger signals with
repetition rates above 100 megahertz and within the
All controls, connectors, and indicators required forthe

range selected by the COUPLING
switch . Stable
operation of the 7B92A, except the Time/Div Variable and

display can be obtained when the
LEVEL control
Mainframe Selectors, are located on the
front panel . A

adjusts the frequency of the
trigger generator to the
brief description of
the front-panel controls, connectors,

frequency (or sub-harmonic) of the trigger signal .
and indicators is given here . More detailed information is

When the LEVEL control is adjusted to frequencies
given under
General Operating Information . Fig . 1-1

between sub-harmonics, the sweep free-runs .
REV B, JUN 1978

REV
B, JUN 1978
POSITION
iRIG .D

,MAIN
TRIGGERIN
/EL
MODE COUPLIR6
SOURCE
0
H f S1'~C

AC
Lf
REJ

UNf
a~ a
EIORY

AC NF
REJ
RESET
CRRTRAST

V<'~tiaFiL~
WALIN
\

TIME/DIV OR DLY TIME
tJW ~
~`~
1f

y . ' E1J
k
i
t OR
O~~O
.
.W
s

.e
i

~ .5

1
r" .
RRRRCE
Fig . 1-3
. Front-panel controls and
connectors .
_
AC INT
IN _
lp
DC ~` EXT ,
OU

YT
19
u
LEVEL
.

0
DLY'D TRIG III

REAIII TRIG III
\

aUT 5SQ

.

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
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DELATTIRIE

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_
TEKTRONIX®
4Y 
DUAL TIME
BASE

YY
7B92A
Operating Instructions-7B92A
1752-17
NORM :
Sweep initiated by the applied trigger
signal

a trigger is received and the
sweep is completed . The
at a point
selected by the LEVEL control and
SLOPE

SINGLE SWEEP-RESET
switch must be pressed
control
over the frequency range selected by the

again before another
sweep can be displayed .
COUPLING switches
. Triggered sweep can be ob-
tained only over the amplitude range
of the applied
trigger signal . When the
LEVEL control is either
outside the amplitude range,
the trigger repetition

O
COUPLING Switches
rate is outside the frequency range selected by the
COUPLING switches,
or the trigger signal is inade-

Select trigger signal coupling .
Selected coupling is
quate, there is no trace .

indicated
by
lighted
pushbutton .
SINGLE SWEEP-RESET :
When the SINGLE
SWEEP-RESET switch is pressed, a single
trace will

AC : Rejects do and attenuates
ac
signals
below
be presented
when thenext trigger pulse is received
.

about 30
hertz . Accepts signals between 30 hertz
The
SINGLE SWEEP-RESET switch remains lit
until

and 500 megahertz .

Operating Instructions-7B92A
AC LF REJ : Rejects do and attenuates signals below
30 kilohertz . Accepts signals between 30 kilohertz
and 500 megahertz .
AC
HF REJ
.
Rejects
do
and attenuates signals
above
50 kilohertz . Accepts signals from 30 hertz to 50
kilohertz .
DC : Accepts all signals from do to 500 megahertz .
V
SOURCE Switches
Select the triggering source . Selected source is
indicated by lighted pushbutton .
INT : °I°rigger signal obtained internally from
amplifier plug-in unit
of
oscilloscope .
LINE : Trigger signal obtained internally from the line
voltage applied to the oscilloscope .
EXT : Trigger signal obtained from an external
source applied to the MAINTRIG IN connector .
EXT --10
:
Trigger
signal obtained from an external

~
VARIABLE
source applied to the MAIN TRIG IN connector . In

Tv,,o_position switch actuated by the VARIABLE
this position, the external signal is attenuated before
it is applied to the trigger circuit .

control to select calibrated or uncalibrated sweep
rates . In the CAL position (knob in) the
VARIABLE
control is inoperative and
the sweep rate is
Sweep Controls

calibrated .
When pressed and released, the knob
moves out to activate the VARIABLE control for
uncalibrated sweep rates . The sweep rate in each
Selects the basic sweep rate for normal sweep

TIME/DIV OR DLY TIME switch position can be
operation
and selects the delay time (multiplied by

reduced at least to the sweep rate of the next slower
the DELAY TIME MULT dial setting) when operating

position . The VARIABLE control will operate
with
in the Alternate or Delayed sweep modes . The

eitherthe delaying or delayed sweep by
means of the
VARIABLE control must be in the CAL (knob in)

internal Time/Div Variable Selector .
position for calibrated sweep rate .
TIME/DIV OR DLY TIME
O
DLY'D Time/Division
turned
clockwise from the ALTOFF position . In this
mode, the delaying sweep is displayed (with an
intensified zone during the time that the delayed
sweep runs) alternately with the delayed sweep .
Intensified
Sweep :
The
Intensified mode, a function
of the delaying and delayed
sweeps is selected when
the DLY'D Time/Division switch
is pulled out and
rotated clockwise, and the TRACE SEP control is
rotated fully counterclockwise to the ALTOFF
position (see Fig . 1-3) . In this mode, a portion of the
delaying
sweep is intensified during thetime that the
delayed
sweep generator runs .
DLY'D Sweep : The Delayed sweep mode is selected
when the DLY'D Time/Division switch is pulled out,
rotated for the desired delayed sweep rate, and then
pushed in . In this mode, the delayed sweep is
displayed at a rate determined by the DLY'D
Time/Division switch at the end of each delay
period, as selected by the TIME/DIV OR DLY °i°IME
switch and the DELAY TIME MULT dial setting .
10
POSITION Control
Selects the delayed sweep rate for operation in

Positions the display horizontally on the graticule .
Delayed and Alternate sweep modes . The
VARIABLE control must be in the CAL (knob in)
position for calibrated sweep rate .
11

CONTRAST Adjustment
Four display modes can be selected by the
following

Varies the relative brightness of the intensified
switch settings :

portion of the delaying trace when in the Alternate
Normal Sweep : A normal sweep is selected when the

mode .
TIME/DIV OR DLY TIME switch and the DLY'D
Time/Division switches are locked together at the
same sweep rate .
The
DLY'D Time/Division knob

12 TRACE SEP/ALT OFF Control
must be pressed in for normal sweep mode .
Calibrated sweep rates from 0 .2 second/division to

This control vertically positions the delaying sweep
0 .5 nanosecond/division can be selected

display up to 3 .5 divisions above the delayed sweep
display when in the Alternate mode . The ALT OFF
ALT Sweep : The Alternate mode is selected when

position allows the Intensified sweep mode of
the DLY'D Time/Division switch is pulled out and

operation, permitting the display of an intensified
rotated clockwise and the TRACE SEP control is

portion of the delaying sweep .
REV B, JUN 1978

13
INTENSITY Control
Varies the intensity of the Intensified sweep
only ;
when
operating in the Intensified or
Alternate mode
(must be set near clockwise
end when7B92A is
operating in some
7000-Series Oscilloscopes) .
~4 SWP CAL Adjustment

~g
COUPLING Switch
Screwdriver
adjustment sets the basic timing of
the
7B92A to compensate for slight differences
in input

Two-position
pushbutton switch to determine
the
sensitivity when changing
indicator oscilloscopes .

method of coupling the trigger signal to
the delayed
trigger circuit .
DELAY TIME
MULT Dial
Provides variable delay of 0 to 9 .8
times the basic
delay time selected by the
TIME/DIV OR DLY TIME
switch .
Delayed TriggeringControls

Front-Panel
Inputs
SLOPE Switch
Two-position pushbutton
switch to select the slope
of the trigger signal
which starts the delayed sweep .
Operating Instructions-7B92A
IN~T : The delayed trigger signal is
obtained from the
vertical amplifier of
the oscilloscope .
EXT : The delayed
trigger signal is obtained from an
external
source connected to the DLY'D
TRIG IN
connector .
AC : Rejects do and attenautes
signals below 30
hertz . Accepts
trigger signals from 30 hertz to 500
megahertz .
DC : Accepts trigger
signals from do to 500
megahertz .
16
LEVEL Control

20
MAIN TRIG IN Connector
Determines the delayed trigger mode and
the

Serves as an external trigger input for
the main
delayed trigger level .

triggering circuit when the MAIN
TRIGGERING
SOURCE EXT or EXT ~
10 pushbutton switches are
RUNS AFTERDELAY TIME
(LEVEL control turned

pressed .
fully clockwise
into detent) : Delayed sweep runs
immediately
following the delaytimeselected bythe
TIME/DIV OR
DLY TIME switch and the DELAY

21
TERM Switch
TIME MUL - f dial . Delayed Slope,
Coupling, and
Source functions are inoperative .

Two-Position
pushbutton switch to select 50 ohms
(out
position) or 1 megohm (in position)
input
Delayed Sweep
Triggerable : When the Delayed

impedance for the MAINTRIG IN and
DLY'D TRIG
Triggering

LEVEL

control

is

turned

IN connectors .
counterclockwise
out of detent, the delayed sweep
is
Trggerable . The Delayed Triggering LEVEL
con-
trol can now be rotated to select the
amplitude point

DLY'D TRIG IN
Connector
on the trigger signal at which
the delayed sweep is

Serves as an
external trigger input for the delayed
triggered . In the Delayed
Sweep Triggerable mode,

triggering
circuit when the Delayed Triggering
the delayed Slope,
Coupling, and Source functions

SOURCE
switch is set to EXT .
are activated .
CAUTION
Do notexceed
7 volts (rms) of external signal when
50 O
termination is selected .
+ : The delayed sweep can be triggered
on the
positive slope of the trigger signal
.

FLINCTICNAL CHECK
-- : The delayed sweep
can be triggered on the

The
following procedures
may
be
used for familiariza-
negative slope
of the trigger signal .
tion or as
a check of basic instrument operation . The
procedure is divided into two parts, Sweep Functions and
18 SOURCE Switch

Triggering Functions . A complete operating check of the
7B92A functions can be made by performing both parts, or
Two-position pushbutton
switch
to
select the source

each part may be performed separately . If performing the
of the delayed
trigger signal .

functional check procedure reveals a
malfunction or
REV A, JUN 1978

Operating Instructions-7B92A
possible improper
adjustment ; first check the operation
of
the associated plug-in units, then
refer to the instruction
manual for maintenance and
adjustment procedures .
NOTE
For optimum high-frequency
performance, the
7B92A should be installed in an
oscilloscope system
with similar
frequency and sweep-rate capabilites .
3 . Adjust the amplifier plug-in
unit volts/division
Setup
Procedure

switch for
two divisions of display .
1 .

I nstall the
7B92A i n a horizontal
compartment of the
oscilloscope .
2 . Install the amplifier plug-in
unit in a vertical com-
partment .
3 . Turn on
the oscilloscope and allow at least
20
minutes warm up .
6 . Check the crt display for one complete
cycle per
division- If necessary, adjust the SWP
CAL screwdriver
4 . Set the
7B92A controls as follows
:

adjustment
for one complete cycle per
division over the
center eight graticule divisions
. Be sure that the timing
of
MAIN °TRIGGERING

the calibrator signal is
accurate within 0 .5% .
SLOPE

(-+)
MODE

AUTO
COUPLING
AC
SOURCE

INT
Delayed Triggering
LEVEL

RUNS AFTER DELAY
TIME
SLOPE

(-§-)
COUPLING AC
SOURCE

INT'
Sweep Controls
Sweep Functions
Normal Sweep . Perform
the following procedure to
obtain a normal sweep and
demonstrate the function of
the related sweep controls
:
1 .
Perform the Setup Procedure .
2 . Connect
a 4 volt, one-kilohertz signal from the
oscilloscope
calibrator to the amplifier plug-in unit input .
4 . Rotate the MAIN
TRIGGERING LEVEL control
fora
stable display .
5 . Rotatethe
POSITIONcontrolandnotethatthetrace
moves horizontally .
Alternate and Delayed Sweep .
Perform the following
procedure
to obtain alternate-delayed
sweeps and
demonstrate
the function of the related
sweep controls :
7 . Pull
out the DLY'D Time/Division
knob and rotate
clockwise
to 0 .1 ms for the Alternate
sweep mode . Note
both an intensified
trace and a normal-intensity
delayed
sweep trace on the crt .
Increased oscilloscope intensity
may be required for viewing the delayed
sweep .
POSITION

Midrange

8 . Rotate
theINTENSITYcontrolandnotethatitvaries
INTENSITY

As desired

the intensity of the delaying
sweep .
TIME/DIV OR

1 ms
DLY TIME
DLY'D
Time/Division

1 ms (knob
in)

9 . Rotate the CONTRAST
adjustment for adequate
VARIABLE

CAL

identification
on the intensified portion
of the delaying
sweep when alternating
with Delayed sweep .
Time/Div Variable

Delayed
Sweep
Selector (internal)
DELAY TIME MULT

1 .00
TRACE SEP

Midrange

NOTE
5 .

Set the
oscilloscope to display the
plug-in units and

When operating in the
Intensified mode, the inten-
adjust for a
well-defined display . See oscilloscope
and

sified zone is controlled by the
intensity of the test
amplifier plug-in unit
instruction manuals for
detailed

oscilloscope instead of the 7B92A
CONTRAST and
operating instructions .

INTENSITY controls .
REV B, JUN 1978

10 .

Rotate the
TRACE SEP control to vertically posi-

and DC, for both the positive and negative positions of the
tion the delaying sweep trace with respect to the delayed

SLOPE control (MAIN TRIGGERING LEVEL
control may
sweep trace . With the TRACE SEP control in
the ALT OFF

be adjusted as necessary
for a stable display) .
position, only the Intensified sweep
will
be displayed
.
18 . Change the MAIN TRIGGERING SOURCE switch
11
. Rotate the DELAY TIME MULT dial and note that

toEXT---10 .Settheoscilloscopecalibratorforfourvoltsat
the
amount of delay time before the intensified portion of

one kilohertz and adjust the amplifier plug-in
unit volts/div
the display is controlled by the DELAY
TIME MULT dial .

switch for about four divisions of display .
Check that a
stable display can be obtained
with the MAIN
TRIGGERING COUPLING switch set to AC, AC HF REJ,
12 .

Press the
DLY'D Time/Division switch in for the

andDC, for both the positive and negative positions of the
Delayed
sweep mode . Note the delayed display with

SLOPE control (MAIN TRIGGERING LEVEL control may
sweep rate determined by the DLY'D
Time/Division

be adjusted as necessary to obtain a stable display)
.
switch .

Remove all connections from the oscilloscope system
.
13 . Press and release the VARIABLE control . Rotate

19 . Set the MAIN TRIGGERING COUPLING switch to
the VARIABLE control and note that the sweep
rate

AC and SOURCE switch to INT . Connect a
one-kilohertz
indicated by theDLY'DTime/Division switch can be
varied

calibrator signal from the oscilloscope to the
amplifier
to at least the sweep rate of the next adjacent position

plug-in unit input and adjust for about four
divisions of
(0 .2 ms) . The internal Time/Div Variable Selector
must be

display
amplitude
. Adjust
the MAIN TRIGGERING LEVEL
set to the Delayed Sweep position
. Return the VARIABLE

control for a stable display . Setthe MODE switch to NORM
control to the
CAL
position
(knob in) .

and check for a stable display . Change the MODE switch
to AUTO and adjust the LEVEL control for afree-running
display . Change the MODE switch to NORM and checkfor
Triggering Functions

no display .
Main and Delayed
Triggering . Perform the following
procedure to obtain a triggered alternate, normal, or

20 . Adjust the MAIN TRIGGERING LEVEL control for
delayed sweep and demonstrate the function of the

a stable display . Change the MAIN TRIGGERING MODE
related controls :

switch to SINGLE SWEEP . Press the RESET button and
14 . Perform the Setup
Procedure . Connect the one-

check for one sweep as the RESET button is
pressed .
kilohertz
calibrator signal from the oscilloscope to the

Removetheone-kilohertzsignalfromtheamplifierplug-in
amplifier plug-in unit input and adjust for about four

unit and press the
RESET button .Checkfornodisplayand
divisions of vertical display .

RESET button light on
. Connect the one-kilohertz signal
to the amplifier plug-in unit input and check for one sweep
as the signal is applied . Remove all connections from the
15 . Set the DLY'D Time/Division
switch and the

oscilloscope system .
TIME/DIV OR DLY TIME switch to
1
ms,
and press in the
DLY'D Time/Division knob
(normal sweep mode) . Rotate
the
MAIN TRIGGERING LEVEL control for a stable

21 .
Set the
MAIN TRIGGERING MODE switch to
display .

AUTO and SOURCE switch to AC . Turn the Delayed
Triggering LEVEL control fully clockwise to the RUNS
AFTER DELAY TIME position . Pull out the
DLY'D
16 . Check that a stable display can be obtained
with

Time/Division switch and rotate to 0 .2 ms (Alternate
the MAIN
TRIGGERING COUPLING switch set toAC, AC

mode) . Connect a 0 .4 volt, one-kilohertz signal from the
HF REJ, and DC,
for both the positive and negative

oscilloscope calibrator to the amplifier plug-in unit input
positions of the
SLOPE control (MAIN TRIGGERING

and adjust for about two divisions of display amplitude .
LEVEL
control may be adjusted as necessary to obtain a

Rotate the MAIN TRIGGERING LEVELcontrolforastable
stable display) . Remove all connections from the os-

intensified display . The INTENSITY control may need to
cilloscope system .

be adjusted to view the intensified display . Rotate the
DELAY TIME MULT dial and note that the delay time
before the intensified portion of display is continuously
17 . Connect a 0 .4 volt, one-kilohertz signal from the

variable .
oscilloscope calibrator to the amplifier plug-in
unit and to
the MAINTRIG IN connector
. Setthe MAIN TRIGGERING
SOURCE
switch
to
EXT . Set the amplifier plug-in unit

22 . Set the Delayed Triggering SLOPE, COUPLING,
volts/div
switch for
about
four divisions of display . Check

and SOURCE switches to (+), AC, and INT . Rotate the
that a stable
display can be obtained with the MAIN

pelayed Triggering LEVEL control counterclockwise out
TRIGGERING COUPLING switch set to AC, AC HF REJ,

of the detent and adjust for a stable display . Rotate the
REV A, JUN 1978
Operating Instructions--7B92A

Operating Instructions--7i392A
DELAY TIME MULT dial and note that the intensified

stable display . Check that stable crt displays can be
sweep does not start at the completion of the delay time

obtained with the
Delayed Triggering COUPLING switch
but waits
for
the next trigger pulse
.

set to AC and DC . Disconnect the
high-frequency
signal
from the oscilloscope system .
23 . Check that a stable display can be obtained with
the Delayed Triggering COUPLING switch set to AC and

Ca NERAI~ ®IP RATING
INF~I~MA°TION
DC for both the (-f-) and (---) positions of the SLOPE switch
(Delayed Triggering LEVEL control may be adjusted as

MAIN TRIGGERING
necessary for a stable display) .

The MAIN TRIGGERINGMODE, COUPLING, and
SOURCE pushbutton switches are arranged in a se
24 . Change the Delayed Triggering SOURCE switch

quence which places the most-often
used position at the
top of each series
of pushbuttons
.
With this arrangement,
to EXT . Connect a 0 .4 volt, one-kilohertz signal from the

a stable display can usually be obtained by pressing the
oscilloscope calibrator to the DLY'D TRIG IN connector .

top pushbuttons : AUTO, AC,andINT . When an adequate
Check that a stable display can be obtained with the

trigger signal is applied and the LEVEL control is set
Delayed Triggering
COUPLING
switch
set to AC andDC,

correctly, the TRIG'D indicator will light
.
If
the TRIG'D
for both the
(+-)
and (-) positions of the SLOPE switch

indicator is not lit : (1) the
LEVEL control is at a setting
(Delayed Triggering LEVEL control may be adjusted as

outside the range of the trigger signal from the amplifier
necessary for a stable delayed sweep display) .

plug-in unit, (2) the trigger signal is inadequate, or (3) the
trigger-signal frequency is belowthelower frequency limit
High-Frequency Synchronization . Perform
the
follow-

of
the COUPLING switch position . If thedesired display is
ing procedure to obtain a triggered
alternate,
normal,
or

not obtained with these pushbuttons, other selections
delayed sweep with a 100 megahertz to 500 megahertz

must be made . Refer to the following discussions or the
input signal :

instruction manuals for the oscilloscope and amplifier
plug-in
unit for more information .
NOTE
To check HF sync operation, a signal source fre-
quency between 100 megahertz and500 megahertz
is required . If a 100 to 500 megahertz signal source is
not available, or if it is not desired to check the HF
sync operation, the last two steps of this procedure
may be deleted .
25 . Change the MAIN TRIGGERING MODE switch to
HF SYNC . Connect a high-frequency signal source (100 to
500
megahertz) to the amplifier plug-in unit input and
adjust for
four divisions of vertical deflection . Adjust the
TIME/DIV OR DLY TIME switch and
DLY'DTime/Division
switch for about six cycles of display . Rotate the MAIN
TRIGGERING LEVEL control throughout its range and
note that the
sweep is alternately stable, then free-
running,
several times during the rotation (stable display
indicates that
the trigger-generator frequency is adjusted
to a sub-harmonic
of
the trigger
signal frequency) . Check
that stable displays can also be obtained with the MAIN
TRIGGERING COUPLING switch set to AC, AC LF REJ,
and DC (MAIN TRIGGERING LEVEL control may be
adjusted,
as necessary, for a stable display) .
26 .

Pull out the DLY'D Time/Division switch and rotate
it to the next fastest sweep rate from the setting of the
TIME/DIV OR DLY TIME switch (Alternate mode) . When
the LEVEL control
is in the detent (RUNS AFTER DELAY
TIME) the display should
be stable . Rotate the LEVEL
control counterclockwise out
of
the detent
and adjust for a
Main Trigger
Modes
The MODE
pushbutton switch selects the mode in
which the main sweep is triggered
.
AUTO . The AUTO pushbutton provides a triggered
display
with
the correct setting of the LEVEL control (see
Trigger Level
discussion) whenever an adequate trigger
signal is applied . The TRIG'D indicator lights when the
display is triggered .
When the trigger repetition rate is outside thefrequen-
cy range selected by the COUPLING switch or the trigger
signal i s i nadeq uate, the sweep free-runs at the sweep rate
indicated
by the
TIME/DIV
OR
DLY
TIME switch
(TRIG'D
indicator off) . An adequate trigger signal ends the free-
running condition and a triggered display is presented .
When the LEVEL control is at a setting outside the
amplitude range of the trigger signal, the sweep also free
runs at the sweep rate indicated by the TIME/DIV OR DLY
TIME
switch
.
This type of free-running display can be
useful when it is desired to measure only the maximum
peak-to-peak amplitude of a signal without observing the
waveshape (such as in bandwidthmeasurements) .
HF SYNC . The HF SYNC
pushbutton
permits stable
displays of repetitive signals with only 0 .5 division of
internal trigger signal (100 millivolts external signal)
required for frequencies between 100 megahertz and 500
megahertz .
REV C,
JUN 1978

Operating Instructionsa--7B92A
A triggered display is obtained when the LEVEL control

When using the Single Sweepmode to photograph
adjusts the frequency of the trigger generator to the

waveforms, the graticule mustbe photographed separate-
frequency or sub-harmonic of the trigger signal . Stable

ly in the normal manner to prevent over-exposing thefilm .
displays may be obtained several times between the limits

Be sure the camera system is well protectedagainst stray
of the LEVEL control, depending on the
amplitude and

light, or operate the system in a darkened room . For
frequency of
the trigger signal . The LEVEL control should

repetitive waveforms, press the
SINGLE SWEEP-RESET'
be
set for optimum display .

(In the High-Frequency

pushbutton
only
once
for
each
waveform unless the signal
Synchronization mode, the display is not necessarily

is completely symmetrical . Otherwise, multiple
stable when the TRIG'D indicator is lit .)

waveforms may appear on the film . For random signals,
the lens can be left open until the signal triggers the unit .
Further information on photographic techniques is given
in the appropriate camera instruction manual .
When the LEVEL control is adjusted between sub-
harmonics of the trigger signal frequency, the trigger
repetition rate is below 100 megahertz or outside the
frequency range selected bythe COUPLING switch, orthe
trigger signal amplitude is inadequate, the sweep free-
runs at the sweep rate determined by the TIME/DIV OR
DLY TIME switch .
Main Trigger Coupling
The MAIN TRIGGERING COUPLING switches select
the method in which the trigger signal is connected to the
trigger circuits
. Each
position permits selection or rejec-
tion of some frequency components of the trigger signal
which trigger the sweep .
NORM . The NORM pushbutton provides a triggered
display with the correct setting of the LEVEL control

AC .
The
AC pushbutton blocks the do
component of
whenever an adequate trigger signal is applied . The

the trigger signal . Signals with low-frequency com
TRIG'D indicator lights when the display is triggered .

ponents below
about
30 hertz are attenuated
.
In general,
ac coupling can be used for most applications . However, if
the signal contains unwanted frequency components, or if
The NORM trigger mode must be used to produce

the sweep is to be triggered at a low repetition rate or do
triggered displays with trigger repetition rates below

level, one of the other COUPLING switch positions will
about 30 hertz . When the TRIG'D indicator is off, no trace

Provide a better display
.
will be displayed .
SINGLE SWEEP . When the signal to be displayed is not
repetitive or varies in amplitude, waveshape, or repetition
rate, a conventional repetitive type display may produce
an unstable presentation . A stable display can often be
obtained under these circumstances by using the single-
sweep feature of this unit . The Single Sweepmode is also
useful to photograph non-repetitive or unstable displays .
To obtain a single-sweep display of a repetitive signal,

AC HF REJ . The
AC
HF
REJ pushbutton passes all low-
first obtain the best possible display in the Normmode .

frequency signals
between about 30 hertz and 50
Then, without changing
the other MAIN TRIGGERING

kilohertz . The do component
is rejected and signals
controls, press the SINGLE SWEEP-RESET pushbutton .

outside the aboverange are attenuated . When triggering
A single trace is presented each time the pushbutton is

from complex waveforms, this position is useful
to
provide
pressed . Further sweeps cannot be presented until the

a stable display of the low-frequency components . AC HF
SINGLE SWEEP-RESET pushbutton is pressed again . If

REJ coupling should not be used when operating in the HF
the displayed signal is a complex waveform composed of

SYNC triggering
mode .
pulses of varying amplitude, successive single-sweep
displays may not start at the same point on the waveform
.
To avoid confusion due to the crt persistence,
allow the

DC .
'The
DC pushbutton can be used to provide stable
display to disappear before pressing
the SINGLESWEEP-

triggering
from low-frequency signals whichwould be
RESET pushbutton again . At fast sweep rates, it may be

attenuated
in the other modes . It can also be used to
difficult to view the single-sweep display . The apparent

trigger the sweepwhen the trigger signal
reaches a do
trace intensity can be increased by reducing the ambient

level set by the LEVEL control . When using internal
light level or
using aviewing
hood as
recommended in the

triggering, the setting of the amplifier plug-in unit position
oscilloscope instruction manual
.

control affects the triggering point .
REV A, JUN 1978
AC LF REJ . 'The AC LF REJ pushbutton rejects dc, and
attenuates low-frequency trigger signals below about 30
kilohertz . Therefore, the sweep is triggered only by the
higher-frequency components of the trigger signal . This
position is particularly useful for providing stabletrigger-
ing if the trigger signal contains line-frequency com-
ponents .
Also,
the
AC
LF REJ position provides the best
Alternate mode vertical displays at fast sweep rates when
comparing two or more unrelated signals .

Operating Instructions-7892A
Main
Trigger
Source

FRONT-PANEL IN
-
1 Mfg . The 1 Mfg position is
The MAIN TRIGGERING SOURCE pushbutton
suitable for most low- and medium-frequency
switches select the source of the trigger signal that is

applications or when using a 10X probe .
The 1 Mfl
connected
to
the main trigger circuits
.

position provides a
high input impedance for minimum
loading on
the trigger signal source .
INT . The INT pushbutton connects the
trigger signal
from the amplifier plug-in unit . Further
selection of the
internal trigger signal may be
provided by the amplifier
plug-in unit or
oscilloscope ; see the instruction manuals
for these instruments for more information
. For most
applications, the internal source can be used
.
However,
some applications require special triggering
that cannot
be obtained in the
INT position . In such cases, the LINE or
EXT positions of
the SOURCE switches must be used .
The MAIN TRIGGERING SLOPE
control (concentric
with the MAIN TRIGGERING
LEVEL control) determines
LINE . The
LINE pushbutton connects a sample of the

whether the trigger circuit responds
on the positive-going
power-line voltage
from the oscilloscope to the trigger

or
negative-going
portion of the trigger signal . The
trigger
circuit . Line triggering is useful
when the input signal is

slope
cannot be selected when operating in
the high-
frequency synchronization mode . When
the SLOPE con-
time-related
(multiple or submultiple) to the line frequen-

trot is in the+ (positive-going)
position, the display starts
cy .
It is also useful for providing a stable display of
a line-

on the positive-going portion of
the waveform ; in the --
frequency component in a complex
waveform . Line

(negative-going) position,
the display starts on the
triggering cannot be used when operating in
the HF sync

negative-going
portion of the waveform (see Fig . 1-4) .
triggering mode .

When
several cycles of a signal appear in the display,
the
setting of the SLOPE control is
often unimportant .
However, if only a certain portion of
a cycle is to be
EXT . The EXT pushbutton connects
thesignalfromthe

displayed, correct setting of
the SLOPE control is impor-
MAINTRIG IN
connector to the trigger circuit . The

tant to provide a
display which starts on the desired slope
external signal must be time-related to the displayed

of the
input signal .
waveform for a stable display . An external
trigger signal
can be used to provide a triggered display
when the
internal signal is too low in amplitude
for correct trigger-

Trigger Level
ing, or contains signal
components on which triggering is

The MAIN TRIGGERING LEVEL control determines
not

desired .

It

is also useful

when signal tracing in

the voltage level on the trigger signal at which thesweepis
amplifiers, phase-shift networks, wave-shaping circuits,

triggered when operating in the Auto, Norm,
or Single
etc . The signal from a single point in the circuit can be

Sweep modes . When the
LEVEL control is set in the ~i-
connected to the MAIN TRIG IN connector through a

region, the
trigger circuit respondsatamorepositivepoint
probe or cable . The sweep is then
triggered by the same

on the trigger signal . When the LEVEL control is set in the
signal at all times and
allows amplitude, time relationship,

-
region, the trigger circuit responds at a more negative
or
waveshape changes of signals at various points in the

point on the trigger signal . Fig . 1-4 illustrates this
effect
circuit to be examined without resetting the MAIN

vdith different settings of
the SLOPE switch .
TRIGGERING controls .
EXT ~-10 . The EXT ~ 10 pushbutton operates the same
as described for EXT except that the external
signal is
attenuated . Attenuation of high-amplitude external
trigger
signals is desirable to increase
the effective range of the
LEVEL control
.
Input Impedance
The input impedance of the
MAIN TRIG IN and DLY'D
TRIG IN connectors
may be selected by the front-panel
TERM
switch .
1- 1 0
FRONT-PANEL OUT -- 50 f2 . The 50
f2 position is
recommended for high-frequency
applications requiring
maximum overal bandwidth
. The 50 ohm termination
should be used when
externally triggering from a 50 ohm
system .
Trigger Slope
To set the LEVEL control, first select the MAIN
TRIGGERINGMODE, COUPLING, SOURCE, and
SLOPE . Then set the
LEVEL control fully
counterclockwise and rotate
it clockwise until the display
starts
at the desired point . Less selection of the triggering
level is available as the trigger signal frequency exceeds
150 megahertz
.
When operating
in the MAIN TRIGGERING HF sync
mode,
the LEVEL control synchronizes the trigger
generator
frequency
to
a sub-harmonic of the trigger
signal frequency . Trigger slope and level cannot be
selected .
REV
A, JUN 1978

CRT DISPLAY
OBTAINED WITH
SLOPE CONTROL
SET TO POSITIVE (+)
CRT DISPLAY
OBTAINED WITH
SLOPE
CONTROL
SET TO NEGATIVE (-)
REV B, JUN 1978
_~ _ T . .___ ~ .,_ .
POSITIVE
(+)
SLOPE
.~_
Operating
Instructions-7B92A
NEGATIVE
-- (_) SLOPE
-_-_
._
Fig .
1-4
.
Effect of MAIN "TRIGGERINGLEVEL and SLOPE
controls on crt display .
1752-05A

Operating
Instructions-7B92A
Selecting Sweep Rates
The TIME/DIV OR DLY TIME switch selects calibrated
sweep rates for the delaying sweep .
The DLY'D Time/Divi-
sion switch selects
calibrated sweep rates for the delayed
sweep . The sweep rate for the delaying sweep is bracketed
by the
black lines on the clear plastic flange of the
TI
ME/DIV
OR
DLY TI ME switch . Sweep rate of the delayed
sweep is indicated by the white line on the DLY'D
Time/Division knob . When the white line on the outer
knob
is set to the same position as the
lines
on
the inner knob,
the two knobs lock together and
the
sweep
rate of both
generators is changed at the same
time . However, when
the
DLY'D Time/Division knob is pulled outward, the clear
plastic flange is disengaged and only the delayed sweep
rate is changed . This allows changing the
delayed sweep
rate without changing the delaying sweep
rate . The
TIME/DIV OR DLY TIME switch and
theDLY'DTime/Divi-
sion switch also select
display modes . See Display Mode
discussion in this section for further information .
1- 1 2
SECOND VERTICAL

TENTH
VERTICAL
LINE

LINE
1
1752-06A
A VARIABLE control is provided concentric with the

1= ;g . ~-5 . Area of graticule used for most accurate time
TIME/DIV OR DLY TIME and DLY'D Time/Division

measurements .
switches (see Fig . 1-3) . This control can be used with
either the delaying or delayed sweeps as determined by

Normal Sweep Operation . To select the Normal sweep
the Time/Div Variable Selector multi-pin connector (inter-

display mode, press in the DLY'D Time/Division switch
nal, see Fig . 1-1 for location) . The VARIABLE control also

and set it to the same sweep rate asthe TIME/DIV OR DLY
incorporates a two-position switch to determine
if
the

TIME switch . Rotate the Delayed Triggering LEVEL
applicable sweep is calibrated or uncalibrated . When the

control clockwise into the detent to the RUNS AFTER
VARIABLE control is pressed in, it is inoperative .

DELAY TIME position .
However, when pressed and released, the VARIABLE
control is activated for uncalibrated sweep rates . The
sweep rate can be returned to the calibrated position by

Calibrated sweep rates in the Normal sweep display
pressing
the VARIABLE
knob
in . This feature is useful

mode are 0 .2 s/Div to 0 .5 ns/Div . By using the VARIABLE
when a specific uncalibrated sweep rate has been ob-

control (Time/Div Variable Selector connector set for
tained and it is desired to switch between calibrated and

variable Delayed Sweep rates) uncalibrated sweep rates to
uncalibrated sweep rates . Switching from uncalibrated to

0 .5
s/Div
are available . Triggering in the Normal sweep
calibrated and vice-versa does not affect the setting of the

display mode is controlled by the MAIN TRIGGERING
VARIABLE control . The VARIABLE control allows the

controls .
sweep rate in each Time/Division switch position to be
increased to at least the next adjacent switch position .
Alternate Sweep Display . To select the Alternate dis-
play mode, pull out the DLY'D Time/Division knob and
rotate it to a desired sweep rate faster than the TIME/DIV
OR DLY TIME switch setting . In this
mode,
both an
Time Measurement

intensified sweep and a delayed sweep are displayed (see
When making time measurements from the graticule,

Fig . 1-6) .
the area between the second and tenth vertical lines of the
graticule provides the
mostlineartimemeasurements(see
Fig . 1-5) . Position the start of the timingareatothesecond

The intensified trace
of
the
Alternate sweep display
vertical line andadjusttheTIME/DIV OR DLYTIMEswitch

provides
an
intensified portion on the delaying sweep
so the end of thetiming area falls between the fourth and

during thetime the
delayed sweep is running . The amount
tenth vertical lines .

of delay time between the start of the delaying sweep and
the intensified portion is determined by the TIME/DIV OR
DLY TIME
switch and the DELAY TIME MULT dial .
Triggering for the delaying sweep portion of the inten-
Display Modes

sified trace is controlled by the MAIN TRIGGERING
Four display modes can be selected by appropriate

controls ; triggering for the
intensified portion of the
settings of the TIME/DIV OR
DLY TIME and DLY'D

delayedsweeptraceiscontrolledbytheDelayedTrigger-
Time/Division switches .

ing controls .
REV B, JUN 1978

Fig . 1-6 . Typical alternate sweep display .
The TRACE SEP control vertically positions the inten-
sified trace up to 3 .5 divisions above the delayed sweep
trace . The brightness of the intensified zone may be varied
by the CONTRAST adjustment . The brightness of the
intensified sweep may be varied bythe7B92A
INTENSITY
control .
Intensified
Sweep Mode . The Intensified sweep mode is
selected when the DLY'D Time/Division switch is pulled
out, rotated to the desired sweep rate faster than the
TIME/DIV OR DLY TIME switch setting, and the TRACE
SEP control is rotated counterclockwise to the ALTOFF
position .
Delayed Sweep Display . The Delayed sweep display
mode is selected when the DLY'D Time/Division switch is
pulled out, rotated to the desired sweep rate, and then
pushed in . In this mode, only the delayed sweep is
displayed .
Operating Instructions-7B92A
The DELAY TIME MULT dial (functional in the Delayed,
Intensified, Alternate,
or
Mainframe Delaying
modes)
provides 0 to 9 .8 times continuous sweep delay .
The
amount of time that the delaying sweep runs before the
start of the delayed sweep is determined by the settings of
the TIME/DIV OR DLY TIME switch and the DELAY TIME
MULT dial .
For example, a DELAY TIME MULT
dial
setting of 3 .55
corresponds
to
3 .55 crt divisions
of
delaying sweep . Thus,
3 .55 multiplied by the delaying sweep rate, indicated by
the TIME/DIV OR DLY TIME switch, gives the calibrated
delay time before the start of the delayed sweep .
Delayed Sweep Triggering
The Delayed Triggering LEVEL control determines the
delayed triggering mode, and delayed triggering level .
When
the
LEVEL
control is intheRUNSAFTER DLY TIME
detent position (fully clockwise),
the delayed sweep starts
immediately after the delay time (determined by the
TIME/DIV OR DLY TIME switch and DELAY TIME MULT
dial) . This mode permits selection of continuously
variable delay times by rotating the DELAY TIME MULT
dial . The
Delayed Triggering LEVEL control and SLOPE,
COUPLING, and SOURCE switches are inoperative .
When the delayed sweep is triggerable (Delayed
Triggering
LEVEL out of the RUNS AFTERDELAY
detent), the delayed sweep
does not start at the comple-
tion of the delaytime . Instead,
it waits until a trigger pulse
is received by the
Delayed Triggering circuits . The delay
time in this mode is dependent not only
on
the settings
of
the delay time controls, but on the Delayed Triggering
controls and the occurrence of the delayed-sweep trigger-
ing signal as well . The primary purpose of this mode isto
eliminate jitter from the delayed sweep is triggered by the
input waveform,
jitter is eliminated from the delayed
sweep display even though it may be inherent in the input
waveform . When jitter in the delayed sweep display is not a
problem, the Runs After Dly Time mode should be used .
In the Delayed Sweep Triggerable
mode, the Delayed
Calibrated sweep rates in the Delayed sweep mode are

Triggering

LEVEL

control

is

rotated

to

select

the
available from

0 .2 s/Div to

0
.5
ns/Div .

By

using the

amplitude point on the trigger signal at which the delayed
VARIABLE control (Time/Div VariableSelectorconnector

sweep is triggered . The Slope, Coupling, and Source
set

for

variable

delayed

sweep

rates),

uncalibrated

functions are the same for delayed triggering as for MAIN
delayed sweep rates to 0 .5 s/Div are available . Triggering

TRIGGERING
(see MAIN TRIGGERING SLOPE, 000PL-
for the delayed sweep is controlled by the Delayed

ING, SOURCE, and TERM switch discussions in this
Triggering controls .

section) .