Tektronix 7B15 User manual

070-2318-00
Product Group 42
IN
Tektronix,
Inc .
P
.O . Box 500
Beaverton, Oregon

97077

Serial Number ___
COMMI1`T"ED TO
EXCELLENCE
K

CHANGE
INFORMATION
2 OF THIS MANUAL .
N MANUAL
First
Printing OCT 1978
Revised APR 1984

Copyright '~)
1978 Tektronix, Inc . All
rights reserved .
Contents of this
publication may not be reproduced
in any
form without the
written permission of 'Tektronix,
Inc
.
Products of
Tektronix, Inc . and its subsidiaries are
covered
by U .S . and
foreign patents and/or pending patents .
TEKTRONIX,
TEK, SCOPE-MOBILE, and

are
registered trademarks
of Tektronix, Inc .
TEL-EQUIPMENT
is a registered trademark of
Tektronix U .K . Limited .
Printed in U .S .A . Specification
and price change privileges
are
reserved .
INSTRUMENT SERIAL
NUMBERS
Each
instrument has a serial number on
a parcel 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
sequentially and are
unique
to each instrument . Those
manufactured in the
United
States have six unique digits .
The country of
manufacture is
identified as follows :
8000000

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

PAGE
LIST OF ILLUSTRATIONS .................................
iii
LIST OF TABLES . . .......................................
iv
OPERATORS SAFETY INFORMATION ....................... v
SERVICE SAFETYINFORMATION ..........................
vi
SECTION 1 GENERAL INFORMATION
INTRODUCTION . . . . . . . . . . .........................
OPERATORS MANUAL .........................
INSTRUCTION MANUAL ........................
INSTALLATION . . . . . . . . . . . . . ......................
INSTRUMENT
PACKAGING . . ......................
SPECIFICATION ........ . . . . . . . . ......................
STANDARD ACCESSORIES . . . . . . . . . . ................
SECTION 2 OPERATING INSTRUCTIONS
CONTROLS, CONNECTORS AND INDICATORS
. ....
OPERATORS CHECKOUT . . . . . . . . . . ................
SETUP PROCEDURE ........ . . . . . . . . . . . . . . . . . . .
SWEEP FUNCTIONS ............. . . . . . . . . . . . . . .
TRIGGERING FUNCTIONS . . . . . . . . . . . . . . . . . . ....
DETAILED OPERATINGINFORMATION . . . . . . . . . . . .
TRIGGERING MODES
.................... . . . . . .
TRIGGER COUPLING . ........ . . . . . . . .
. . . . . . . . . .
TRIGGER SOURCE ............ . . . . . . . . . . .
. . . . . .
TRIGGER SLOPE ............................. .
TRIGGER LEVEL
...............................
HORIZONTAL
SWEEP RATES ....... . . . . . . . . . . .
TIME MEASUREMENTS
........................
SWEEP MAGNIFICATION
.......................
VARIABLE HOLD
OFF
.........................
DELAY-TIME OPERATION
......................
A TIME OPERATION
...........................
MAINFRAME OPERATING MODES
............
2APPLICATIONS ..................................
2DELAYED-SWEEP MEASUREMENTS
..............
2TIME-INTERVAL MEASUREMENTS
(DELAY-TIME MODE) .........................
2-12
DIFFERENTIAL TIME-INTERVAL
MEASUREMENTS (A TIME MODE) ............
2-12
DELAYED-SWEEP MAGNIFICATION ............ 2-14
TRIGGERED
DELAYED-SWEEP
MAGNIFICATION . . . . . . ........................ 2-16
INDEPENDENT TIME-INTERVAL
MEASUREMENTS ..... . . . . .
. . . . . . . . . . . . . . . . ...... 2-16
THE REMAINING PORTION
OF THIS TABLE OF
CONTENTS LISTS THESERVICING
INSTRUCTIONS .
THESE SERVICING INSTRUCTIONS ARE
FORUSE
BY QUALIFIED PERSONNEL
ONLY
.
T O AVOID
ELECTRICAL SHOCK, DO NOT PERFORM
ANY
SERVICING OTHER THAN THAT CALLED
OUT IN
THE OPERATING INSTRUCTIONS
UNLESS
QUALIFIED TO DO SO .
7B15
PAGE
SECTION 3 THEORY OF OPERATION
BLOCK DIAGRAM DESCRIPTION .....................
3-1
TRIGGER
GENERATOR ............................
3-1
SWEEP GENERATOR
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-1
PICKOFF
COMPARATORS AND
DELAY
GATE GENERATOR . . . . . . . . . . . . . . . . . . . . . . .
3-1
GATE GENERATOR ............................. .
3-11
DELAY PICKOFF COMPARATORS
............. 3-11
DELAY AND 0 TIME REFERENCE
VOLTAGESOURCES ..........................
3-12
DELAY GATE GENERATOR . . . ..... . . . . . . . . . . .
3-12
DIGITAL
VOLTMETER .
. . .
. . . . . . . . ..... . . . . . . . .
. . . 3-12
DELAY COMPARISON VOLTAGE TO
RAMP
CONVERTER
. .
. . . . . . . . . . . . . . . . . . . . . . . . .
3-12
COMPARATOR
....... . . . . . . . . . . . . . . . . . . . . . . .
. 3-14
REFERENCE CURRENT SOURCE . . . . . . . . . . . . ... 3-14
REFERENCE
CURRENT INVERTER . . . . ... ..... 3-14
COUNTER AND ENCODER ....................
3-14
TIME/DIVISION AND READOUT
SWITCHING . . . . . 3-14
BASIC READOUT SYSTEM
....................
3-14
TIME/DIVISION READOUT ....................
3-14
DELAY TIME READOUT .......................
3-15
A SYMBOL ENABLE ..........................
3-15
INTERFACE CONNECTORS AND
POWER SUPPLY
.................................
3-15
1-1
1-1
1-1
1-1
LOGIC
...................
. . . . . . . . . . .. . . . . . .
. . . . .
. . 3-1
DIGITAL
VOLTMETER .... . . . . . . . . . . . . . . . . . . . . . . . . .
3-1
DETAILED CIRCUIT DESCRIPTION . . . . . . . . . . . . . . . . . . . .
3-3
LOGIC FUNDAMENTALS . . . . . . . . . . . . . . . . . . . . . . . . . .
3-3
1-1
SYMBOLS
...............
. . . . . . . . . . . . . . . . . . . . . .
3-3
1-2
LOGIC POLARITY
...........
. . . . . . . . . . . . . . .
. . . . 3-3
1-5
INPUT/OUTPUTTABLES .... . . . . . . . . . . . . . . . . . . .
3-3
NON-DIGITAL DEVICES ........ . . . . . . . . . . . . . . . . . . . 3-3
FRONT-PANEL . WIRING . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
2-1
TRIGGER GENERATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-3
2-1
EXTERNAL
TRIGGER AMPLIFIER . . . . . . . . . . . . ... 3-3
2-1
TRIGGER AMPLIFIER
AND
2-1
SOURCE SELECTOR ........ . . . . . . . . . . . . . ......
3-7
2-4
SLOPESELECTOR AND
2-5
TRIGGER GENERATOR . .
. .
. . . . . . . . . . . . . . . . . . . . . 3-7
2-5
GATE GENERATOR . ........ . . . . . . . . . . . . . . . . ... 3-7
2-6
LOGIC ............................................
3-7
2-6
TRIGGER MODE SWITCHING . . . . . . . . . ......... 3-7
2-6
HOLD OFF TIMING ............ . . . . ............ 3-8
2-8
LOCKOUT
BUFFER AMPLIFIER ................. 3-9
2-8
HOLD OFF GENERATOR
.......................
3-9
2-8
DELAY MODE CONTROL ......................
3-9
2-8
AUXILIARY Y-AXIS ............................
3-9
2-8
SWEEP GENERATOR ............................
3-10
2-8
TIMING CURRENT
SOURCE
...................
3-10
2-9
RAMP GENERATOR ..........................
3-10
-10
OUTPUT PREAMPLIFIER ......................
3-11
-10
AUXILIARY SWEEP PREAMPLIFIER
............ 3-11
-10
SWEEP GATE GENERATOR ...................
3-11
PICKOFF COMPARATORS AND DELAY

PAGE
SECTION 4 MAINTENANCE
PREVENTIVE MAINTENANCE ......................... 4-1
CLEANING ........................................ 4-1
EXTERIOR ..................................... 4-1
INTERIOR ..................................... . 4-1
SWITCH CONTACTS ........................... 4-1
VISUAL INSPECTION .............................. 4-1
LUBRICATION .................................... 4-1
CAM SWITCH LUBRICATION
...................
4-1
SEMICONDUCTOR CHECKS ....................... 4-2
ADJUSTMENT AFTER REPAIR ..................... 4-2
TROUBLESHOOTING .................................
4-3
TROUBLESHOOTING AIDS ........................ 4-3
DIAGRAMS ................................... . 4-3
TROUBLESHOOTINGCHART ................... 4-3
VOLTAGES AND WAVEFORMS ................ 4-3
CIRCUIT-BOARD ILLUSTRATIONS ............... 4-3
SWITCH CAM IDENTIFICATION ................. 4-3
DIODE COLOR CODE
..........................
4-3
WIRING COLOR CODE ......................... 4-3
SEMICONDUCTOR BASING .................... 4-3
INTER-BOARD PIN CONNECTOR
IDENTIFICATION ............................... 4-3
MULTI-PIN CONNECTOR IDENTIFICATION ....... 4-3
INTERFACE
CONNECTOR PIN LOCATIONS ...... 4-3
ADJUSTMENT
AND PERFORMANCE CHECK ....... 4-3
TROUBLESHOOTING EQUIPMENT .............. 4-5
TROUBLESHOOTING
TECHNIQUES ................ 4-6
1
.
CHECK CONTROL SETTINGS ................ 4-6
2 . CHECK ASSOCIATEDEQUIPMENT .......... 4-6
3 . VISUAL CHECK ............................. 4-6
4 . CHECK INSTRUMENT ADJUSTMENT ........ 4-6
5 . ISOLATE TROUBLE TO A CIRCUIT .......... 4-6
6 . CHECK VOLTAGES AND WAVEFORMS ...... 4-6
7 . CHECK INDIVIDUAL COMPONENTS ......... 4-6
TRANSISTORS .................................
4-7
INTEGRATED CIRCUITS ........................
4-7
DIODES ................. . ... . .................
4-7
RESISTORS .............. . . . . . . . . . . . . . . . . . . .... 4-7
INDUCTORS
............ . . . . . . . . . . . . . . . . . . . . . . . 4-7
CAPACITORS . . . . . . . . . . . . . . . . . . ..... . . . . ..... . .
4-7
8 .
REPAIR AND ADJUSTMENT . . . . . . . . . . . . . . . . . 4-7
CORRECTIVE
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
OBTAINING REPLACEMENT' PARTS . ..... . ... . .... 4-8
SOLDERING TECHNIQUES . . . . . . . . . . . . . . . . . . . . . . . .
4-8
PAGE
COMPONENT
REMOVAL AND REPLACEMENT ..... 4-9
CIRCUIT
BOARDS
.............................
4-9
SWITCHES ...................................
4-10
HYPCON CONNECTORS .......................
4-12
INTERCONNECTING
PINS ..................... 4-13
FRONT-PANEL LIGHTS . . . . .
................... 4-16
ADJUSTMENT
AFTER REPAIR .................... 4-16
INSTRUMENT
REPACKAGING . ................... 4-16
SECTION 5 CALIBRATION
CALIBRATION .......................................
5-1
PRELIMINARY INFORMATION ..................... 5-1
USING
THESE PROCEDURES .................. 5-1
ADJUSTMENT INTERVAL ...................... 5-2
TEKTRONIX FIELD SERVICE
. . . . . . . . . . . . . . . . . . . . 5-2
TEST
EQUIPMENT REQUIRED ..................... 5-6
SPECIAL FIXTURES . ........................... 5-6
1 - EST EQUIPMENT ALTERNATIVES . . . . . . . . . . . . . 5-6
PART I-PERFORMANCE CHECK . . . . ........ . ......... 5-8
PERFORMANCE CHECK PROCEDURE
INDEX ......
5-8
PERFORMANCE CHECK
POWER-UP
SEQUENCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... 5-8
A . TRIGGERING SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-9
B . HORIZONTAL SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-14
PART II-ADJUSTMENT
AND PERFORMANCE
CHECK . . . ... .......................................
5-23
ADJUSTMENT AND PERFORMANCE
CHECK INDEX . . ................. . ..... . . . . . . . . . . 5-23
ADJUSTMENT AND PERFORMANCE CHECK
POWER-UP SEQUENCE .......................... 5-23
A . TRIGGERING SYSTEM ........................... 5-24
B . HORIZONTAL SYSTEM .......................... . 5-29
SECTION 6
INSTRUMENT OPTIONS
SECTION 7 REPLACEABLE ELECTRICAL PARTS
SECTION 8 DIAGRAMS AND CIRCUIT
BOARD
ILLUSTRATIONS
SECTION
9 REPLACEABLE MECHANICAL PARTS
CHANGE INFORMATION

FIGURE
NO .
Frontis-
piece
1-1
1-2
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2-11
REVA MAY 1979
7815 Features ................................ . vii
Location of release latch . . . . . . . . . . . . . . . . . . . . . . 1-1
71315
dimensional drawing
. . . . .
.
.
. . . . . . ... . . . . 1-5
Front-panel controls, connectors,
and indicators ..................... . ...........
2-2
Effects of LEVEL control and SLOPE
switch on crt display ..........................
2-7
Area of graticule used for most accurate
time measurements ...........................
2-8
Effect of sweep magnifier on crt
display ....... 2-9
(A) Delaying-sweep display
produced by 7815
in the A horizontal compartment . (B)
Delayed-
sweep
display produced bycompanion
time-base unit in the B horizontal
compartment ..................................
2-9
Typical A (Differential Time Operation ........ 2-11
Measuring time intervals from a triggering
event (start of sweep) to any point on
waveform . ...................................
2-12
Measuring
risetime, fall time, period,
frequency, or
pulse width in the L (differential)
time mode . . . . . . .............................
2-13
Magnifying a
selected segment of the delaying
(A) sweep in the
delay-time mode with
mainframe alternate or
chopped horizontal
operation ........ . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
Time-interval measurements in
the delay-time
and A (differential) time mode with mainframe
alternate or chopped operation . . . . . . . . . . . . . . .
2-15
Examining an event that occurs within a
selected time interval after a known delay
time in the delay-time mode . . . . . . .
. . . . . . . . . . 2-16
FIGURE
PAGE
NO .
3-2
3-3
3-4
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
4-11
4-12
4-13
Basic block diagram of the 7815 Delaying
Time Base unit .............................. .,
3-2
Timing diagram for
Gate Generator stages
Q160, Q164, and Q174 . . . . . . . . . . . . . . . . . . . . . . . 3-8
Timing diagram for Delay Pickoff
Inhibit stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-10
Digital Voltmeter timing diagram
.. .
.
. . . . . . . . . . 3-13
Lubrication procedure for a typical
cam switch 4-2
Semiconductor lead configuration ..............
4-4
Inter-board multi-pin connector
assembly
.......
4-5
End-lead multi-pin connector assembly .........
4-5
Location of pin numbers on Interface connector 4-5
P38 cable dress illustration ...................
4-10
Readout board removal procedure .............
4-11
Coaxial end-lead connector assembly .........
4-12
Cam switch removal procedure ............... 4-14
Removal procedure for typical push-
button switch
...............................
.
4-17
Hypcon connector removal and replacement . . .
4-18
Exploded view of circuit-board pin
and ferrule . . . ............................
. . . . 4-20
Front-panel light
socket assembly ... . . . . . . . . . . 4-20
8-1

Semiconductor lead configuration .
8-2

Location of circuit boards in the 7815 .
8-3

A1-Interface circuit board assembly .
8-4

A2-Trigger circuit board assembly .
8-5

A3-Readout circuit
board assembly .
8-6

A4-Digital
Voltmeter circuit board assembly .
8-7

Location
of Sweep Timing adjustments .
8-8

Location of Digital Voltmeter
adjustments .
8-9

Location of Triggering
adjustments .
71115
PAGE

TABLE
NO .
PAGE
1-1 Electrical
Characteristics ... . .
. ... .. . . . . . .
1-2
1-2
Environmental Characteristics . . ... .. . ..
. . .
1-5
1-3 Physical Characteristics . . . . . . . ... .. . . . . . .
1-5
3-1 Basic Logic Reference . . . . . .. ... ... ... ...
3-4
3-2
Readout Character Selection .. ... ... ... ... 3-15
5-1 Performance Check Summary
.. ... ... ... ... 5-2
5-2 Test
Equipment ... . .. ... . .. ... ... ... ... 5-6
5-3 A Time Accuracy . . .. ... ... ... ... ... ...
5-19
5-4 Sweep Timing . . . . . .. ... ... ... ... ... ...
5-21
5-5
Magnified Sweep Timing .. ... ... ... ... ... 5-22
5-6 A Time Accuracy . ... ... ... . .
. ... ... ..
.
5-37
5-7 Sweep Timing .... .. . ... ... . .
. . . .
... .. .
5-39
5-8 Magnified
Sweep Timing .. ... .. ... .... .. . 5-40

The following general safety information applies to all operators and service personnel . Specific warnings
and cautions
will be found throughout the manual where they apply and should be followed in
each instance .
WARNING statements identify
conditions or practices which could
result
in
personal injury or loss of life .
CAUTION statements identify
conditions or practices which could result in
damage to the equipment or other property .
GROUNDING THE INSTRUMENT
To reduce electrical-shock hazard, the mainframe
(oscilloscope) chassis
mustbe properly grounded . Refer to
the mainframe manual for grounding
information .
DO NOT REMOVE INSTRUMENT
COVERS
[6+0+A RNING
DO NOT OPERATE IN EXPLOSIVE ATMOSPHERE
PREVENT INSTRUMENT DAMAGE
To avoid electric-shock hazard,
operating personnel must not remove the
protective instrument covers .
Component replacement and internal adjustments
must be made by qualified service personnel only .
To avoid explosion,
do not operate this instrument in an explosive
atmosphere unless it has been certified for
such operation .
7B15
Plug-in
units should not be installed or removed without
first turning the instrument power off, to prevent instrument
damage .

Refer also to the preceding
Operators Safety Summary
The following are safety precautions which appear in the servicing information sections of this manual . This Servicing
Safety
Summary
is in addition to the Operators Safety Summary given previously .
DO NOT SERVICE ALONE
V I

I

.

!B

I , Vrrr
FOR
QUALIFIED SERVICE
PERSONNEL ONLY
Do not attempt internal service or adjustment unless another person,
capable
of rendering first aid and
resuscitation, is present .
DISCONNECTINSTRUMENT
POWER
To avoid electric-shock disconnect the instrument from the
power
source
before
removing protective panels,
soldering, or replacing components .
SILICONE GREASE HANDLING
Handle silicone
grease
with care
. Avoid getting the silicone grease in youreyes . Wash hands thoroughly after
use .
AVOID EXCESSIVE MOISTURE
Circuit boards and components must be dry before applying power to prevent damage from electrical arcing .
EXERCISE CARE WHEN
CHECKING DIODES
When checking diodes,
do notuse an ohmmeter scale that has a high internal current,
since
high
currents
may damage the diodes under
test .
EXERCISE CARE WHEN SOLDERING
ON MULTI-LAYER BOARDS
All but the Readout circuit board in the
instrument are mufti-layer type boards with a conductive path
laminated between the top and
bottom board layers . All soldering on these boards should
be
done with
extreme care to prevent breaking the
connections to this center conductor . Only experienced maintenance
personnel should attempt
repair of these boards .
USE
PROPER CLEANING
AGENTS
Avoid the use of chemical
cleaning agents which might damage the
plastics used in this instrument . Usea
non-residue type of cleaner, preferablyisopropyl
alcohol, totally denatured ethyl
alcohol, or Freon TF Before
using any other type of cleaner, consult
your Tektronix Service Center
or
representative
.
DO NOT USE PIN SOCKETS FOR CONNECTION
POINTS
The spring tension
of the pin sockets ensures a good connection between the
circuit board and the pin . This
spring tension can
be
destroyed
by using the pin sockets as a connecting
point for spring-loaded probe tips,
alligator clips,
etc .
7815
Vi

7815
71315
Features
2319-1
The
71315 Delaying Time-Base
unit provides calibrated sweep rates from .2 seconds
to 2 nanoseconds and
triggering
to 1 Gigahertz for 7100-, 7700-, 7800-,
and 7900-series oscilloscopes . The X10
Magnifier increases each sweep
rate by
a
factor of 10 and a
VARIABLE control allows continuously variable sweep rates
between calibrated steps .
Variable
hold off and alpha-numeric
readouts are provided . Also, when operating in the AUTO
TRIGGERING
MODE, a bright
baseline trace is displayed
in the absence of a trigger signal .
Other
features include independent
sweep
operation of
continuously variable sweep delay
(DELAY TIME)
and
differential
sweep delay (A TIME) with a companion
time-base unit . Delay time or
differential delay time readout
is
displayed on the mainframe cathode-ray
tube .

INTRODUCTION
OPERATORS MANUAL
INSTRUCTION MANUAL
The Operators Manual contains
information necessary to
effectively operate the 71315 Time Base and
is divided
into three sections : Section 1
provides a basic
description of the 71315 with instrument
specifications
and
accessories ; section 2 contains
operating
information for
the instrument ; instrument option
information
is located in section 3 of the manual .
The Instruction Manual provides both operating and
servicing information for the 71315 Time Base . The
Instruction
Manual is divided into nine sections .
Operating information is covered in the first two sections ;
servicing information for
use by qualified service
personnel is contained in the remaining
seven sections
of the manual . Schematic diagrams
are located at the
rear of the manual and can be unfolded for
reference
while reading other parts of the manual . The
reference
designators and symbols used on the
schematics are
defined on the first page of the Diagrams and Circuit
Board
Illustrations section . All abbreviations used in this
manual, with the
exception of the parts lists and
schematic diagrams, comply
with the American National
Institute Y1 .1-1972 publication .
The parts lists are
computer printouts and use
computer-supplied
abbreviations . Instrument option
information is located in
section 6
of
the Instruction
Manual
.
INSTALLATION
The time-base
unit
is
designed to operate in
the
horizontal plug-in compartment of the mainframe . This
instrument can also be installed in a vertical plug-in
compartment to provide a vertical sweep on the crt .
However, when used in this manner, there are no
internal triggering or retrace blanking provisions, and the
unit may not meet specifications .
To install the unit in a plug-in compartment, align the
upper
and
lower rails
of the plug-in with the mainframe
tracks
and
push it
in until it fits firmly into the
compartment . The front panel of the unit should be
flush
with the front panel of
the
mainframe . Even though
the
gain of the mainframe is standardized, the sweep
calibration of the unit should be checked
when
installed .
The procedure for checking the unit is given under
Sweep Functions in the Operators Checkout procedure in
section 2 .
To remove the unit, pull the release latch (see
Fig .
1-1 ) to
disengage the unit
from the mainframe,
and
pull
it out of
the plug-in
compartment .
INSTRUMENT PACKAGING
If this instrument is to be shipped for long distances by
commercial means of transportation, it is recommended
that it be repackaged in the original manner for
maximum protection . The original shipping carton should
be saved and used
for
this purpose .
If
more information is
needed, contact your local Tektronix Field Office or
representative .
RELEASE
LATCH
Figure 1-1 . Location of release latch .
Section 1---7815
(196013)2319

General Information-_-71315
This instrument will meet the
electrical characteristics
listed in
Table 1-1, following
complete adjustment . The following
electrical characteristics
are valid over the stated
environmental
range for instruments
calibrated at an ambient
temperature of +20° to
+30° C, and after a
twenty-minute
warmup unless
otherwise noted .
Sweep Rates
Calibrated Range
Variable Range
Sweep Accuracy' with
7104, 7900 and
7800
Series
Mainframes
+15 to +35° C
0 .2 s/div to
10 ns/div
5 ns/div and 2 ns/div
- -- ---- - -------
0 to +50° C
Excluded Portions of Sweep
7104
Position Range
Characteristics
7800,
7900 Series
- -------------

------
Sweep Length
MAG Registration
POSITION Controls fully
CW
POSITION Controls fully CCW
'Some mainframes limit
fastest calibrated sweep rate .
TABLE 1-1
Electrical Characteristics
PerformanceRequirement
===---4- = - .--
.-_ .~--T_ --_ .
SWEEP GENERATOR
2 200 ps/div is measured
over
any
5 divisions within the center
8 divisions .
0 .2 s/div to
2 ns/div in 25 steps . X10 Magnifier extends
fastest calibrated
sweep rate to 0 .2 ns /div .
Continuously
variable uncalibrated sweep rate to at least
2 .5 times the calibrated
sweep rate setting .
- ----------
------
Measured over center 8 displayed divisions .
SWP CAL is
adjusted at 1 ms/div within the +20
to
+300 C
range .
(71315
Delay Mode Switch set to Independent .)
UNMAG

-
MAG
X10
None .
Derate +15 to
+35° C accuracy by additional 1 % .
First 5 ns .
At least 10 .2 div .
0 .5 div or less from graticule center when changing from
MAG X10 to MAG X1 .
Start of sweep
must be to right of graticule center at
1 ms/div .
End of sweep must be left of graticule
center at 1 ms/div .
--- ------------ --

A TIME
+15 0 to +35 0 C
0 0 to +50
0
C
- TRACE SEP Range
DELAY
TIME
Range
J itter
Characteristics
Range
Accuracy (20 ms/div to 100 ns/div) -
0 .2
s/div
to 50 ps/div
20 us/div to
100 ns/div
Absolute Delay Accuracy
(Start of delayed sweep
with respect to start of delaying
sweep ; 0 0 to
+50
0
C)
0 .2 s/div to 10 /is/div
Differential Measurement Accuracy (Measure-
ment is made by subtracting 2 delay time
readings
; 0 .2 s/div to 100 ns/div ;
0 0 to 50 0 C)
3 The
triggering
frequency ranges given
here are limited to the -3
Internal
mode .
TABLE 1-1
(CONT .)
Electrical Characteristics
Performance Requirement
VARIABLE TIME
DELAY
0 .0
to at least 9 .0 times TIME/DIV setting .
Within (0 .5%
of Measurement + 3 digits) .
Within (0 .5% of Measurement
+ 4 digits) .
Functional only in the
ns
TIME Mode
when alternating or
chopping between timebase units
.
The
second delayed
sweep
display can be vertically positioned at
least
3 divisions
below the first delayed sweep display when
the
mainframe
vertical trace separation control
is centered .
0 .2 or less to at
least 9 .0 times TIME/DIV setting .
(0 .02% of TIME/DIV
setting) or less
(0 .03% of TIME/DIV
setting + 100 ps) or less .
Within
(0 .5% of Delay + 5% of
TIME/DIV setting) .
Within
(0 .5% of
Measurement + 4 digits) .
General
Information--71315
dB
frequency of the oscilloscope vertical
system when operating in the
`Will not
trigger on sine waves
at or below 60Hzwhen amplitudes are less than 8 divisions Internal
or 3 volts External
.
'The Triggering Frequency Range for DC COUPLING applied
to frequencies above
30 Hz when operating in the AUTO TRIGGERING
MODE
.
Trigger
Sensitivity for Repetitive Signals
TRIGGERING
- - -----------
Triggering
Frequency Minimum Triggering
Range 3
Signal Required
Coupling
Internal External
AC
30 Hz to 250 MHz
0 .5 div
^
50 mV
250 MHz to 1 GHz
1 .5 div 150 mV
AC LF REJ"
50
kHz
to 250 MHz
0 .5
div
50 mV
250 MHz to 1 GHz 1
.5
div
150 mV
AC HF REJ
30 Hz
to 30 kHz 0 .5 div
50
mV
DC S
Dc to
250 MHz 0 .5 div
50 mV
250 MHz
to
1
GHz 1 .5 div 150 mV

General Information -7B15
Charectedstics
AC, AC LFREJ.oxOC
External Trigger Input
Shoe Sweep
Internal Trigger Jitter
Operating in HF SYNC MOPE
LEVEL
RANGE
Maximum
Safe Input
1-Megohm
Input
50-Ohin Input
Input R and C
1-Megohm Input
50-Ohm Input
Trigger Holdoff 'Time
Minimum Holdoff Sotting 6
0 .2 s/div to 50ms/div
20 mo/divto 2,us/div
1 j us/div to 2ns/d
Maximum Ho!doff Satting«
0 .2 u/div$o5Umo/dbv
20ms/divto2Ao/1iv
1xo/divtuO .5xs/div
0 .2 «o/div to 8 no/div
GPerformance requirement not checked
in the manual .
TABLE 1'1(CONT .)
Electrical Characteristics
PerformanceRequirement
Same as for Repetitive and Pulsed
Triggering .
3Opaovless at 1GHa .
---
25DV(doplus peak o0-
1 Watt average .
1MU within 5%, 20 pf within 10% .
50 Q within 2% .
4Uins, or less
2dmes TIME/DIV setting, or less
2 .0 gs, or less
400 ins, or greater
20 timesTIME/DIV setting, or greater
20 .0 ps, or greater
6 .0 us, or greater
250 MHz to 1 8Ha' 0 .3 div Internal
75 mV External
At least
+
and -3 .5 V(checked on 1
kHz sine wave) .
REV xUw188u

TABLE 1-3
Physical
Choractm,iotioo
Net Weight

Approximately 2 .6 pounds (1 .2 kilogram) .
Dimensions

See Figure 1-2, dimensional
drawing .
1 ea . . . . ...... .. .. .. .. .. .. .... .. .. .. . ..................... .. . .
. Operators
Manual
1na . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . .
.. . ... . . ... .
.. .
. . . . . . . .
Instruction
Manual
NOTE :

TOPFIGURES
IN INCHES
LOWER
FIGURES IN CENTIMETERS
Referto be Specification section of the
associated mainframe manual .
TABLE 1-2
Environmental Characteristics
OVERALL
DIMENSIONS
(MEASURED AT MAXIMUM
POINTS)
pigu* 1'2 . 7o15
dimensional drawing .
General Information-78115

The
71315 Time-Base unit operates with a Tektronix
7100-, 7700-, 7800-, or 7900-series oscilloscope mainframe and a
7A-series amplifier
unit to form a complete oscilloscope system .
This section describes the operation of the front-panel
controls
and connectors, provides detailed operating
information, an operators checkout procedure, and
basic
applications for this instrument .
CONTROLS, CONNECTORS, AND
INDICATORS
All controls, connectors, and indicators
required for the
operation of the
time-base unit are located on the
front
panel . Figure
2-1 provides a brief description of all front-
panel controls,
connectors, and indicators . More
detailed
information is given
in the Detailed Operating
Information portion of
this section .
OPERATORSCHECKOUT
The following procedures are
provided for checking basic
instrument functions . Refer
to the description of the
controls, connectors, and indicators
while performing
this procedure . If performing
the functional check
procedure reveals a
malfunction or possible
maladjustment, first check the
operation of the
associated plug-in units, then refer
to the instruction
manual for maintenance and adjustment
procedures .
SETUP PROCEDURE
1 . Install the 71315
in the A horizontal compartment
of
the mainframe
.
2 . Install an
amplifier plug-in unit in a
vertical
compartment .
3 . Set the 71315 controls as follows
:
SLOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (+)
MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AUTO
COUPLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AC
SOURCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INT
B DELAY MODE . . . . . . . . . . . . . . . . . . INDEPENDENT
TRACE SEP . . . . . . . . . . . . . . . OFF (fully
clockwise)
POSITION . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Midrange
TIME/DIV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 ms
VARIABLE (CAL IN) . . . . . . . Calibrated
(Pushed in)
HOLD OFF . . . . . . . . . MIN (fully counterclockwise)
MAG . . . . . . . . . . . . . . . . . . . . . . . . . . . . X1 (pushed in)
EXT TRIG IN . . . . . . . . . . . . . . . . . . . . . . . . OUT 50 O
4 . Turn on the oscilloscope and allow at least
20 minutes
warmup .
5 .
Set the mainframe
vertical and horizontal modes to
display the plug-in units
used and adjust the intensity
and focus for a well-defined display . See the oscilloscope
mainframe and amplifier
unit instruction manuals for
detailed operating instructions
.
SWEEP FUNCTIONS
Normal
Sweep
Perform the following procedure to obtain
a normal
sweep and to demonstrate the function of the
related
controls
:
1 . Perform
the preceding Setup Procedure .
Section 2--71315
2 . Connect a
0 .4-volt, 1-kilohertz signal from the
mainframe calibrator to the amplifier
plug-in unit input .
3 . Set the amplifier plug-in
unit deflection factor for 4
divisions of display .
4 . Adjust
the
LEVEL
control for a stable display .
5 . Turn the
POSITION control and note that the trace
moves horizontally .
6 . Turn the FINE control and note that
the display can be
precisely positioned horizontally .
7
.
Check the display for one complete cycle per division
.
If
necessary, adjust the front-panel SWP CAL
screwdriver
adjustment for
one complete cycle per division over the
center
8
graticule
divisions . Be sure that the timing of the
mainframe calibrator
signal is accurate to within 0 .25%
(+20 0 to +30 0 C) .
8 . Press to release the VARIABLE
(CAL IN) control . Turn
the VARIABLE (CAL IN) control fully
counterclockwise
and
note that the displayed sweep rate changes
to at
least the next slower TIME/DIV switch
setting (i .e ., 2
milliseconds/division) . Press the VARIABLE
(CAL IN)
knob in
to
the
calibrated position .
Magnified
Sweep
Perform the following
procedure to obtain a X10
magnified display and to demonstrate
the function of the
related controls :
1 . Obtain a one cycle
per
division
display as described in
the preceding Normal Sweep procedure
.
2 . Press to release the MAG button (X10) . Note
that the
unmagnified display within the center division
of the
graticule is magnified to about 10 divisions .
3 .
Press the MAG
button (X1) .

Operating Instructions-41315
2-2
Figure 2-1
. Front-panel controls, connectors and
indicators .

LEVEL Control-Selects a point on the trigger signal where triggering occurs .
07
SLOPE
Switch--Permits sweep to be triggered on negative- or positive-going portions of
the trigger signal .
READY Indicator--Illuminates when sweep circuit is armed (SINGLE SWP MODE) .i,
TRIG'D Indicator--Illuminates when the display is triggered .
MODE Pushbuttons--Selects the operating mode of the triggering circuits .
COUPLING Pushbuttons . --Selects the method
of coupling the trigger signal to triggering circuit .
SOURCE Pushbuttons--Selects source of
the trigger signal .
POSITION
Control---Provides horizontal positioning .
FINE Control-Provides precise horizontal positioning .
EXT TRIG
Button-Selects input impedance .
TRIGGERING
SWEEP
MAG Pushbutton-Selects
X10 magnified or unmagnified sweep .
TIME/DIV
Switch--Selects the sweep rate of the sweep generator .
EXTERNAL TRIGGER INPUT
EXT TRIG IN
Connector--Connector (BNC type) provides input for external trigger signals .
SWEEP MODE
DELAY TIME
Figure 2-1 (Cont .) . Front-panel controls, connectors, and indicators .
Operating Instructions---71315
HOLD OFF Control-Permits hold off period to be varied to improve triggering stability of repetitive
complex
waveforms .
VARIABLE
Control and CAL Switch--Selects calibrated or uncalibrated sweep rates . Uncalibrated sweep rates can
be
continuously reduced to at least the sweep rate of the next slower position .
SWP CAL
Adjustment---Compensates for basic timing changes due to the differences in sensitivity of mainframes in
which the 71315
may he used .
B DELAY MODE Pushbuttons--Selects independent or delaying sweep operation . In the B STARTS AFTER DLY and B
TRIGGERABLE AFTER DLY delaying sweep modes, the DELAY TIME
and A TIME functions
are activated . There will
be a
2 division vertical shift of the trace when switching
from INDEPENDENT to B STARTS
AFTER DLY .
DELAY TIME Control-- Provides variable delay time before the start of the delayed sweep produced by companion
time-base
unit .
TRACE
SEP Control and Switch---Enables A TIME functions and provides vertical separation of the delayed sweep
traces (,n~
TIME operation) .
A TIME Control--Provides differential time measurements between 2 selected intensified zones on the delaying
sweep trace . Two delayed sweep traces corresponding to the intensified zones are displayed by the companion
time-base unit . Differential time is displayed on the crt readout .

Operating
Instructions---71315
Delaying And
Delayed Sweep
Perform the following procedure to obtain delaying- and
delayed-sweep displays and to demonstrate the function
of the related controls . To obtain a delayed-sweep
display,
a
companion
time-base unit must be installed in
the B horizontal compartment of the mainframe
.
1 . Obtain a display as described in the preceding Normal
Sweep procedure .
2 . Press the B STARTSAFTER
DELAY
button .
3 . Set the mainframe horizontal mode for chopped
operation .
4 . Set the companion time-base
unit
sweep rate
for
0 .1
millisecond/
division, and triggering for auto mode, ac
coupling, internal source, and + slope .
5 . Adjust the mainframe B sweep intensity and check for
an intensified zone about 1 division wide on the delaying
(A) sweep display . Also note that the delayed (B) sweep
provides an expanded display of the intensified portion of
the delaying (A) sweep .
6 . Position the start of the delaying
(A)
sweep to the left
edge of the graticule .
7 . Adjust
the DELAY TIME control for a crt readout
(bottom division
of crt
graticule) of 5.000 ms . Check that
the left edge of
the intensified zone is at the graticule
center line .
8 . Set the 71315 TIME/DIV switch to .5 ms and the
delayed
(B) sweep unit sweep rate to
20
microseconds/division .
9 . Turn the DELAY TIME control fully counterclockwise to
position the intensified zone near the front corner of the
first square-wave cycle . Press the B TRIGGERABLE
AFTER IDLY button and check that the intensified zone
moves to the
front corner
of
the next
displayed square
wave .
! 1 . (Differential) Time
Perform
the
following
procedure to obtain a
(differential) time display and
to demonstrate the function
of the related controls :
1 . Obtain a
delaying (A) and delayed (B) sweep display
as
described in steps 1 through 4 of the preceding Delaying
and Delayed Sweep procedure .
2 . Turn the TRACE SEP control counterclockwise out of
the OFF (detent) position .
3 . Set the DELAY TIME and A TIME controls to the fully
counterclockwise position . Check for two delayed (B)
sweeps and note that the
crt readout (bottom
right of crt)
is 0 .000 ms .
2- 4
4 . Slowly turn the A TIME control clockwise and note
that a second intensified zone moves across the delaying
(A) sweep display and the crt readout indicates the
differential time between the left edge of the stationary
intensified zone and the left edge of the second
intensified zone . Also note that the lower delayed (B)
sweep is an expanded display of the second intensified
zone .
TRIGGERING
FUNCTIONS
Perform the following procedure to obtain a triggered
sweep and to demonstrate the functions of the related
controls :
1 . Obtain a display as described in the preceding Normal
Sweep procedure .
2 .Turn the LEVEL control fully counterclockwise to obtain
a free-running sweep .
3 . Slowly turn the HOLD OFF control clockwise and note
that a stable display can be obtained at several positions
of the HOLD OFF control . Return the HOLD OFF control
to the
fully counterclockwise (MIN)
position
.
NOTE
The HOLD OFF
control varies the sweep hold-
off time which
effectively changes the
repetition rate of the
horizontal sweep signal .
However, its primary function
is to obtain a
stable display of complex
waveforms which
are otherwise difficult to trigger .
4 . Press the AC, AC HF REJ, and DC COUPLING buttons
for both the + and - positions of the SLOPE switch and
check for a stable display (LEVEL control may
be
adjusted, if necessary, to obtain a stable display) .
5 . Apply the 0 .4-volt, 1 kilohertz signal from the
mainframe calibrator to the amplifier plug-in unit and to
the EXT TRIG IN connector .
6 . Press the EXT SOURCE button and set the amplifier
plug-in unit deflection factor for a 4-division display .
7 .
Press the
AC, AC HF REJ, and DC COUPLING buttons
for both the + and - positions of the SLOPE
switch and
check for a stable display (LEVEL control
may be
adjusted, if necessary, for a stable display) .
8 . Press the AC COUPLING, INT SOURCE, and NORM
MODE buttons . Adjust the
LEVEL
control for a stable
display .
9 .
Press the
AUTO
MODE
button
and
adjust the LEVEL
control for a free-running display .

10 .
Press the
NORMMODE button
and check for no
display .
11 . Adjust the LEVEL
control for a stable
display and
press the SINGLE SWP
MODE button .
12 . Note that one
trace occurs when the
SINGLE SWP
button is pressed
again
.
13 . Disconnect the mainframe
calibrator signal
from the
amplifier plug-in
unit input and
press the SINGLE
SWP
button .
Check for no display and
note that the READY
indicator
is lit .
14 . Note
that one trace occurs and
that the READY
indicator extinguishes
when the mainframe
calibrator
signal is reconnected
to the amplifier plug-in unit
input .
DETAILED
OPERATING INFORMATION
Triggering
Switch Logic
The MODE,
COUPLING, and
SOURCE push buttons
of the
TRIGGERING
switches are arranged
in a sequence
which
places the most-often
used position
at the top of
each
vertical row
of push buttons .
With this arrangement,
a
stable display can
usually be obtained by
pressing the
top
push buttons : AUTO,
AC, INT . When an
adequate trigger
signal is applied
and the LEVEL control
is correctly set,
the
unit is triggered
as indicated by the
illuminated
TRIG'D light . If the
TRIG'D light is not on,
the LEVEL
control is either at
a setting outside the
range of the
trigger
signal applied
to this unit from the
vertical unit ;
the trigger signal
amplitude is inadequate,
or its
frequency is below the lower
frequency
limit of the AC
COUPLING
switch position .
If the desired display
is not
obtained
with these buttons
pushed in, other
selections
mustbe
made . Refer to the
following discussions
or the
instruction
manuals for the
associated
oscilloscope
mainframe and
vertical unit(s) for more
information .
TRIGGERING
MODES
The
MODE push-button switches
select
the mode in
which
the sweep is triggered
.
Auto
The
AUTO MODE provides a triggered
display with the
correct setting of the LEVEL
control whenever an
adequate trigger signal is applied
(see Trigger Level
discussions) . The TRIG'D light indicates
when the display
is triggered
.
When the trigger
repetition rate
is outside the frequency
range selected
by the COUPLING switch
or the trigger
signal is
inadequate, the sweep
free runs at the
rate
indicated by the
TIME/DIV switch (TRIG'D
indicator off) .
An adequate trigger
signal ends the
free-running
condition and a triggered
display is
presented . The sweep
also free runs at the
rate indicated by
the TIME/DIV
switch when the LEVEL
control is at a setting
outside the
amplitude range
of the trigger signal .
This type of free-
running display
is useful when it is desired
to measure
only the peak-to-peak
amplitude of
a signal without
observing the waveshape
(such as
bandwidth
measurements) .
Hf Sync
The HF
SYNC mode provides
a triggered display
with the
correct setting
of the LEVEL
control whenever
a high
frequency,
(100 MHz or higher)
low amplitude
signal is
applied . This
mode is most useful
when the incoming
signal
is too small to produce
stable triggering in
the
AUTO
or NORMAL modes . The HF
SYNC mode
increases
trigger sensitivity
and provides
automatic trigger
amplifier
centering for optimum
triggering under these
conditions .
Normal
The NORMMODE provides
a triggered display
with the
correct setting
of the LEVEL control
whenever an
adequate trigger
signal is applied . The
TRIG'D light
indicates when
the display is triggered
.
The normal trigger
mode must be used
to produce
triggered displays
with trigger repetition
rates below
about
30 hertz . When the
TRIG'D light is off,
no trace is
displayed
.
Single
Sweep
Operating
Instructions--"71315
When the signal
to be displayed is
not repetitive or varies
in in amplitude,
waveshape, or
repetition rate, a
conventional
repetitive type display
may produce an
unstable presentation
. Under these
circumstances,
a
stable display can
often be obtained by using the
single-
sweep feature of this
unit . The single-sweep
mode is also
useful to
photograph
non-repetitive or
unstable displays .
To
obtain a single-sweep
display of a
repetitive signal,
first obtain the best
possible display in the
NORM MODE .
Then,
without changing
the other TRIGGERING
controls,
press the
SINGLE SWP
RESET button . A single
trace is
presented
each time this
button is pressed
. Further
sweeps cannot be presented
until the
SINGLE SWP
RESET
button is pressed
again . If the displayed
signal is a
complex
waveform composed
of varying amplitude
pulses,
successive single-sweep
displays may not
start at
the same point
on the waveform .
To avoid confusion
due
to the crt
persistence, allow the
display to disappear
before
pressing the SINGLE
SWP RESET button
again . At
fast sweep rates,
it may be difficult
to view the single-
sweep display .
The apparent trace
intensity can
be
increased by reducing
the ambient light
level or by using
a
viewing hood as
recommended in
the mainframe
instruction manual .
When using the single-sweep
mode to
photograph
waveforms, the graticule
may have
to be
photographed
separately in the
normal manner
to prevent
over-
exposing the film .
Be sure the
camera system
is well
protected against
stray light, or
operate the
system in a

Operating
Instructions---71315
darkened room . For
repetitive waveforms,
press the
SINGLE SWP
RESET button only once
for each waveform
unless the
signal is completely symmetrical
. Otherwise,
multiple 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 .
TRIGGER COUPLING
The
TRIGGERING COUPLING
push buttons select the
method in
which the trigger signal
is connected to the
trigger
circuits . Each position
permits selection or
rejection
of some frequency
components of the signal
which
triggers the sweep .
Alternating Current
AC COUPLING
blocks the do component
of the trigger
signal . Signals with
low-frequency
components 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
sweep is to
be triggered at a low
repetition rate or do
level,
one of the other
COUPLING switch positions will
provide a
better display .
Alternating
Current Low Frequency
Rejection
AC LF
REJ COUPLING rejects
dc, and attenuates low-
frequency
trigger signals below
about 50 kilohertz .
Therefore,
the sweep is
triggered only by the higher-
frequency components of
the trigger signal . This
position
is particularly useful for
providing stable triggering if
the
trigger signal
contains linefrequency
components . Also,
the AC LF REJ
position provides the best
alternate-mode
vertical displays at fast
sweep rates when
comparing two
or more
unrelated signals .
Alternating
Current High Frequency
Rejection
AC
HF REJ COUPLING passes
all low-frequency signals
between
about 30 hertz and 30
kilohertz . Dc is rejected
and signals outside the
above range are attenuated .
When triggering from
complex waveforms, this position
is useful to
provide a stable display of the
low-frequency
components .
Direct Current
DC COUPLING can
be used to provide stable
triggering
from
low-frequency
signals whichwould be
attenuated
in
other COUPLING
switch positions . DC
COUPLING can
be used to
trigger the sweep when the
trigger signal
reaches a do level
set by the LEVEL control
. When using
internal triggering,
the setting of
the vertical plug-in unit
position
control affects the triggering
point .
TRIGGER
SOURCE
The
TRIGGERING SOURCE
push buttons select
the
source of the trigger
signal which is connected to
the
trigger circuits .
Internal
The INT
position connects
the trigger signal from the
vertical
plug-in unit .
Further selection of the
internal
trigger signal may be
provided by the vertical plug-in
unit
or by the
mainframe ; 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
which
cannot be
obtained in the INT position
. In
such
cases the
LINE or
EXT positions of the SOURCE
switches must be
used .
Line
The LINE position
connects a sample of the
power-line
voltage from the
mainframe to the trigger circuit .
Line
triggering is useful
when the input signal is
time-related
(multiple or
submultiple) to the line
frequency . It is also
useful for
providing a stable display of
a line-frequency
component
in a complex waveform
.
External
TheEXT position connects the
signal from the EXT TRIG
IN
connector to the trigger
circuit . The external signal
must
be time-related to
the displayed waveform for a
stable
display . An external
trigger signal can be used to
provide a triggered display
when the internal signal is
either too low
in amplitude for correct
triggering or
contains signal
componentson which triggering
is not
desired . It is
also useful when
signal tracing in
amplifiers,
phase-shift networks,
wave-shaping circuits,
etc . The signal
from a single point in the
circuit can be
connected to
the EXT TRIG IN connector
through a probe
or cable
. The sweep is then
triggered by the same signal
at all times
and allows amplitude,
time relationship, or
waveshape
changes of signals at
various points in the
circuit to
beexamined without
resetting the TRIGGERING
controls
.
The

IN

1 Mfg/OUT

5052

push

button

provides

a
convenient
means of selecting external
trigger input
impedance
. Pushing the button
in sets the amplifier input
impedance to 1 MQ and the
OUT position provides 5052
input impedance .
TRIGGER SLOPE
The TRIGGERING
SLOPE switch
(concentric with the
TRIGGERING
LEVEL control) determines
whether the
trigger circuit
responds on the positive- or
negative-going
portion of the
trigger signal . When the
SLOPE switch is
in the (+)
(positive-going) position, the display
starts on
the positive-going
portion of the waveform (see
Fig . 2-2) .
When several
cycles of a signal appear
in the display, the
setting of the
SLOPE switch is often
unimportant .
However,
if only a certain portion of a
cycle is to be
displayed, correct setting
of the SLOPE switch is
important
to provide a display that
starts on the desired
slope of
the input signal .