Tektronix 47E5A, DM44 Instruction Manual

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. Tektronix, Inc.
P.O.
500
Beaverton, Oregon
97077
070·2163
·00
TEKTRONIX®
47E5A
DSCILLDSCDPE
AND
DM44
DIGITAL
MULTIMETEA
PEA
INSTRUCTION
MANUAL
Serial Number
___
Fi
rst Printing AUG. 1976
WARRANTY
All
TEKTRONIX
instruments
are
warranted
against
defective
materials
and
workmanship
for
one
year.
Any
questions
with
respect
to
the
warranty
should
be
taken
up
with
your
TEKTRONIX
Field
Engineer
or
representative.
All
requests
for
repairs
and
replacement
parts
should
be
directed
to
the
TEKTRONIX
Field
Office
or
representative
in
your
area.
This
will
assure
you
the
fastest
possible
service. Please
include
the
instrument
Type
Number
or
Part
Number
and
Serial
Number
with
all
requests
for
parts
or
service.
Specifications
and
price
change
privileges
reserved.
Copyright
© 1976
by
Tektronix,
Inc.,
Beaverton,
Oregon.
Printed
in
the
United
States
of
America.
All
rights
reserved.
Contents
of
this
publication
may
not
be
reproduced
in
any
form
without
permission
of
Tektronix,
Inc.
U.S.A.
and
foreign
Tektronix
products
covered
by
U.S.
and
foreign
patents
and/or
patents
pending.
TEKTRONIX
is a
registered
trademark
of
Tektronix,
Inc.
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TABLE OF
CONTENTS
Page
LIST
OF
ILLUSTRATIONS
iv
BASIC
OSCILLOSCOPE
DISPLAYS
LIST
OF
TABLES
v
NORMAL
SWEEP
DISPLAY
MAGNIFIED
SWEEP
DISPLAY
BEFORE
OPERATING
1
DELAYED
SWEEP
DISPLAY
INTRODUCTION
MIXED
SWEEP
DISPLAY
SAFETY
INFORMATION
1
X-Y
DISPLAY
OPERATING
VOLTAGE
1
SINGLE
SWEEP
DISPLAY
Line
Voltage
Selection
2
Regulating
Range
Selection
2
DM44
DISPLAYS
AND
MEASUREMENTS
OPTIONS
3
RESISTANCE
CONTROLS,CONNECTORS,AND
VOLTS
INDICATORS
4
TEMPERATURE
VERTICAL
4
Accuracy
Check
DISPLAY
7
TIME
AND
1/TIME
DM44
7
TRIGGER
8
HORIZONTAL,
CALIBRATOR,
AND
POWER
12
APPLICATIONS
AND
MEASUREMENTS
REAR
PANEL
14
PRELIMINARY
LEFT SIDE
PANEL
14
Signal
Ground
RIGHT
SIDE
PANEL
14
Input
Coupling
Capacitor
Precharging
@
475A/DM44
Operators
Page
16
16 17
17
18 18 19
20
20 22
24 24 27
28
28 28 28
TABLE OF
CONTENTS
(cont)
APPLICATIONS
AND
MEASUREMENTS
(cont)
Page
APPLICATIONS
AND
MEASUREMENTS
(cont)
Page
OPERATOR'S ADJUSTMENTS
AND
CHECKS
29
PHASE DIFFERENCE MEASUREMENTS
42
Trace Rotation
29
HIGH
RESOLUTION PHASE DIFFERENCE
Probe Compensation
29
MEASUREMENTS
43
Vertical Gain Check
30
PULSE JITTER MEASUREMENTS
44
Basic 475A
Timing
Check
30
DELAYED OR MIXED SWEEP
DM44
Timing
Check
30
MAGNIFICATION
45
External Horizontal Gain Check
31
Magnified Sweep Starts
After
Delay
45
PEAK-TO-PEAK VOLTAGE
Triggered
Delay Sweep
Magnification
46
MEASUREMENTS-AC
31
INSTANTANEOUS
VOLTAGE
BASIC
475A DELAYED OR
MIXED
SWEEP
TIME
MEASUREMENTS-DC
32
ALGEBRAIC
ADDITION
34
MEASUREMENTS
48
COMMON MODE REJECTION
35
TIME
DIFFERENCE BETWEEN REPETITIVE
AMPLITUDE
COMPARISON
PULSES (BASIC
475A) 48
MEASUREMENTS
36
TIME DURATION MEASUREMENTS
TIME-DURATION
MEASUREMENTS
37
(BASIC 475A) 49
FREQUENCY
MEASUREMENTS
38
FREQUENCY MEASUREMENTS (BASIC 475A)
50
RISETIME MEASUREMENTS
39
TIME
DIFFERENCE BETWEEN TWO PULSES
TIME DIFFERENCE
BETWEEN TWO
. FROM DIFFERENT SOURCES (BASIC
475A)
51
PULSES FROM DIFFERENT SOURCES
40
RISETIME (BASIC
475A)
52
TIME COMPARISON MEASUREMENTS
41
MIX (BASIC 475A)
53
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TABLE OF
CONTENTS
(cont)
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DM44
DELAYED
OR
MIXED
SWEEP
TIME
Page
OPERATOR
'S
SPECIFICATIONS
(cont)
Page
MEASUREMENTS
54
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TIME
DIFFERENCE
BETWEEN REPETITIVE Z
AXIS
INPUT
65
PULSES
(DM44)
56
OUTPUTS
65
TIME
DURATION
MEASUREMENTS
(DM44)
57
AC
POWER
SOURCE
65
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FREQUENCY
MEASUREMENTS
(DM44) 58
ENVIRONMENTAL
65
TIME
DIFFERENCE
BETWEEN
TWO
PULSES
DM44
DIGITAL
MULTIMETER
66
FROM
DIFFERENT
SOURCES
(DM44)
58
RESISTANCE
66
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RISETIME
(DM44)
60
TIME
66
MIX
(DM44)
61
1/TIME
66
TEMPERATURE
66
OPERATOR'S
SPECIFICATIONS
62
DC
VOLTAGE
66
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475A
OSCILLOSCOPE
62
VERTICAL
62
TRIGGERING
63
ACCESSORIES
68
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DIFFERENTIAL
TIME
MEASUREMENT
STANDARD
ACCESSORIES
68
(BASIC
475A)
63
OPTIONAL
ACCESSORIES
68
DIFFERENTIAL
TIME
MEASUREMENT
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(DM44)
64
HORIZONTAL
64
OPTIONS
69
X-Y
64
OPTION
4
69
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CALIBRATOR
64
OPTION
7
69
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475A/DM44
Operators
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LIST OF
ILLUSTRATIONS
I
Page
Page
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Fig.
1.
Regulating
range
selector
and
line
Fig. 17.
Common-mode
rejection.
36
fuse.
3
Fig. 18.
Time
duration.
38
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Fig. 2.
Vertical
controls,
connectors,
and
Fig. 19. Risetime.
39
indicators.
4
Fig.
20.
Time
difference
between
two
pulses
Fig.
3.
Display
and DM44
controls,
from
different
sources. 40
connectors,
and
indicators.
6
Fig. 21.
Phase
difference.
43
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Fig.
4.
Trigger
controls,
connectors,
and
Fig. 22.
High-resolution
phase
difference.
43
indicators
.
8
Fig. 23.
Pulse jitter.
44
Fig . 5.
Trigger
controls, connectors,
and
Fig.
24.
Delayed sweep
magnification.
46
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indicators.
10
Fig. 25.
Time
difference
between repetitive
Fig.
6.
Horizontal,
calibrator,
and
power
pulses. 49
controls,
connectors
, and
indicators.
12
Fig. 26.
Time
duration.
50
Fig.
7.
Rear panel and left side panel
controls,
Fig. 27.
Time
difference
between
two
pulses
I
connectors,
and
indicators.
15
from
different
sources.
51
Fig.
8.
Resistance.
21
Fig. 28. Risetime .
53
Fig.9.
Volts.
23
Fig. 29.
Time
difference
between repetitive
I
Fig. 10.
Temperature.
25
pulses.
56
Fig. 11.
Probe
compensation
.
29
Fig. 30.
Time
duration
and
frequency
Fig. 12.
Basic
475A
timing
check
.
30
measurements
.
57
Fig. 13.
DM44
timing
check
.
31
Fig. 31.
Time
difference
between
two
pulses
I
Fig.
14.
Peak-to-peak voltage
of
a waveform.
32
from
different
sources.
59
Fig. 15.
Instantaneous
voltage
measurements.
33
Fig. 32. Risetime.
60
Fig.
16.
Algebraic
addition.
35
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475A/DM44
Operators
I
LIST OF TABLES
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Page
Page
TABLE 1 Regulating
Ranges
2
TABLE 4 Centigrade
to Fahrenheit
Conversion
26
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TABLE
2 Resistance Ranges
20
TABLE
5 DM44 Delayed Sweep
Displays
54
TABLE
3 Volts Ranges
22
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475A/DM44
Operators
v
475A
Oscilloscope
with
DM44
Digital
Multimeter.
475A1DM44 Operators
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BEFORE
OPERATING
INTRODUCTION
The
Tektronix
475A
Oscilloscope
is a dual-channel
portable
instrument.
The
dual-channel
dc-to-250
MHz
vertical
system
provides
calibrated
deflection
factors
from
5
millivolts
to
10
volts/division. The
sweep
trigger
circuits
are
capable
of
stable
triggering
over the full
bandwidth
capabilities
of
the
vertical
deflection
system .
The
horizon-
tal
deflection
system
provides
calibrated
sweep rates
from
0.5
second
to 0.
01
microsecond/division
along
with
delayed sweep features
for
accurate
relative-time
measurements. A
X10
magnifier
extends
the
calibrated
sweep
rate
to 1 nanosecond/division. The
instrument
operates
over a wide
variation
of
line
voltages and
frequencies. Maximum
power
consumption
is
about
100
watts
.
The
Tektronix
DM44
Digital
Multimeter
measures 0
ohm
to
20
megohms, 0 dc
volt
to 1200
dc
volts
(+
or
-),
or
(using
the
temperature
probe)
- 55°C to
+150°C. The
measurement
is
displayed
on
a 3-1/2
digital
display
while
the
oscilloscope
operates
normally
.
The
digital
multimeter
and
oscilloscope
combine
to
provide a digital
readout
of
the
time
between
any
two
points
on the
oscilloscope
display.
Both
time
measure-
ment
points
are
displayed
on the
crt
at the same
time. The
1/
TIME
function
can
provide
direct
measurement
of
frequency.
SAFETY
INFORMATION
The
instrument
is
designed
to operate from a
single-
phase
power
source
with
one
of
the
current-carrying
conductors
(the
Neutral
Conductor)
at
ground
(earth)
potential.
Operation
from
power
sources
where
both
current-carrying
conductors
are live
with
respect to
ground
(such as phase-to-phase on a three-wi
re
system)
is
not
recommended, since
only
the Line
Conductor
has
over-current
(fuse)
protection
within
the
instrument.
The
instrument
has a
three-wire
power
cord
with
a
three-terminal
polarized
plug
for
connection
to
the
power
source
and safety-earth.
The
ground
(earth) terminal
of
the
plug
is
directly
connected
to
the
instrument
frame.
For
electric-shock
protection,
insert
this
plug
only
in a mating
outlet
with
a safety-earth
contact.
@
475A/OM44
Operators 1
OPERATING VOLTAGE
~
This
instrument
may
be
damaged
if
operated
with
the line voltage
selector
switch
or the
regulating
range
selector
set
for
the
wrong
applied
line voltage
or
if
the
wrong
line fuse is
used
.
Line Voltage Selection
This
instrument
operates from
either
a 115-volt
or
a
230-
volt
nominal
line
voltage
source, 48 to 440 hertz.
To
convert
from
one
nominal
line
voltage
range to the other,
move the Line
Voltage
Selector
switch
(located
on
side
panel) to
indicate
the
correct
nominal
voltage. A 115-to-
230
volt
adapter
may be required
for
the
line-cord
plug
. Be
sure to use the
correct
line fuse for the line
voltage
selected (see
Table 1).
Regulating Range Selection
The
Regulating Range
Selector
assembly (located on
the rear
panel) is set
for
one
of
the line voltage ranges
shown
in Table 1. It also
contains
the
line fuse
for
overload
protection.
To
change
the
regulating
range:
1.
Disconnect
the
instrument
from the
power
source
.
2. Loosen the
two
captive screws
that
hold
the cover
on the
selector assembly; then
pull
to
remove the
cover
.
3.
Pullout
the range
selector
switch
bar (see Fig. 1).
Select a range from Table 1
which
is
centered
about
the
average
line voltage . Slide the bar to the desired
position
and
plug
it in. Push the
cover
on and
tighten
the
screws
.
TABLE
1
Regulating Ranges
Regulating Range
Range
Selector
115-Volts. 230-Volts
Switch Position
Nominal Nominal
LO
(Switch bar
in
lower
holes)
99 to
121
volts
198
to
242 volts
M (Switch bar
in
middle
holes) 104
to
126
volts
207
to
253
volts
HI (Switch
bar
in
upper
holes)
108
to
132 volts 216
to
264 volts
Fuse Size
1.5 A
3AG
0.75 A
3AG
Fast-blow Fast-blow
2
475A/DM44 Operators
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LINE
FUSE
1739·1
Fig. 1. Regulating range selector and line fuse.
OPTIONS
Options
are available to
alter
oscilloscope
performance
to
meet
particular
applications. A number
in
either
MOD
slot
(see Item 53,
Controls,
Connectors,
and
Indicators)
indicates a modified
oscilloscope.
475A/OM44
Operators
3
4
CONTROLS,
CONNECTORS
AND
INDICATORS
Fig.
2.
Vertical
controls,
connectors,
and
indicators.
VERTICAL
1.
CH 1 and
CH 2 VOL
TS/DIV-Selects
the
vertical
deflection
factor
in a 1-2-5
sequence
(VAR
control
must
be
in the
calibrated
detent
for
the
indicated
deflection
factor).
2.
VOL
TS/DIV
Readout-Consists
of
two
small
lamps
for
each
channel, located
beneath
the
skirt
of
each
VOL TS/OIV
knob. One
or
the
other
lamp
will
light
up
to
indicate
the
correct
deflection
factor
when a probe
with
a
scale -
switching
connector
is used. A
probe
without
this
connector
lights
the
X1
lamp.
3.
VAR-Provides
continuously
variable
uncalibrated
deflection
factors between the
calibrated
settings
of
the
VOL
TS/ OIV
switch,
and
extends
the
maximum
vertical
deflection
to at least 25 volts
per
division
(10 volt
position).
4.
UNCAL
Lamp-Indicates
when
the
VAR
VOL TS/ OIV
control
is
out
of
the
calibrated
detent
and the
vertical
deflection
factor
is
uncalibrated
.
475A/DM44
Operators
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5.
POSITION-Positions
the
display
vertically
. In the
X-V
mode,
the
CH 1 POSITION
control
positions
on
the X
axis
(horizontally)
and
the
CH 2 POSITION
control
positions
on
the Y-axis
(vertically).
6.
CH
1 OR X
and
CH
2 OR
V-Input
connectors
for
application
of
external
signals
to
the
inputs
of
the
vertical
amplifier.
In the X-V
mode
of
operation,
the
signal
connected
to
the
CH 1 OR X
connector
provides
horizon-
tal
deflection
and
the
signal
connected
to
the
CH
2 OR Y
connector
provides
vertical
deflection.
7.
AC-GND-DC-Selects
the
method
used to
couplea
signal
to the
input
of
the
vertical
amplifier
. In
the
AC
position, signals
are
capacitively
coupled
to
the
vertical
amplifier. The
dc
component
of
the
input
signal
is
blocked
.
In
the
GND
position,
the
input
of
the
vertical
amplifier
is
disconnected
from
the
input
connector
and
grounded
to
allow
the
input
coupling
capacitor
to
precharge.
In
the
DC
position,
all
components
of
the
input
signal are passed to
the
input
amplifier.
8.
VERT
MODE-Selects
mode
of
operation
for
ver-
tical
amplifier
system
.
CH
1:
Channell
only
is di
splayed.
AL
T: Provides
dual-trace
display
of
the
signals
of
both
channels. Display
is
switched
between
channels
at
the
end
of
each sweep.
Useful
at sweep rates faster than
about
50
microseconds/division
.
ADD: Signals
applied
to the
CH 1 and
CH 2 input
connectors
are
algebraically
added, and
the
algebraic
sum
is
displayed
on
the crt.
The
INVERT
switch
in
Channel
2
allows
the
display
to be
CH 1 plus
CH 2 or
CH 1
minus
CH
2.
Useful
for
common-mode
rejection
to
remove
an
undesi
red
signal
or
for
dc
offset.
CHOP
: Provides
dual-trace
display
of
the
signals
of
both
channels. Display
is
switched
between
channe
ls at a
repetition
rate
of
approximately
250 kHz .
Useful
at
sweep
rates
slower
than
about
50
microseconds/division, or
when a dual-trace, single-sweep
display
is
required
.
CH
2:
Channel 2 only
is
displayed.
It
must
be selected
in X-
Y
operation
.
9.
100 OR 20
MHz
BW/TRIG
VIEW-
Three-purpose
switch
that
limits
the
bandwidth
of
the
vertical
amplifier
system
to
approximately
100
MHz
(first
detent)
or20
MHz
(second
detent)
when
pulled, or
when
pressed, causes the
signal
applied
to
A Tr
igger
Generator
to
be
displayed
on
the crt.
10.
INVERT-Channel
2
display
is inverted in the
INVERT
(button
in)
position.
@
475A/DM44
Operators
5
Fig.
3.
Display and DM44 controls, connectors, and
indicators.
6
475A/DM44 Operators
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DISPLAY
11.
Internal
Graticule-Eliminates
parallax. Risetime.
amplitude
and
measurement
pOints are
indicated
at the
left-hand
graticule
edge.
c,
12.
BEAM
FINDER-Compresses
the
display
to
within
the
graticule
area
independently
of
display
position
or
applied
signals
and
provides a visible
viewing
level.
13.
INTENSITY-Controls
brightness
of
the
crt
dis-
play.
14.
FOCUS-Adjusts
for
optimum
display
definition
.
15.
SCALE
ILLUM-Controls
graticule
illumination.
16.
ASTIG-Used
in
conjunction
with
the
FOCUS
control
to
obtain a well-defined
display
. It
does
not
require
readjustment
in
normal
use.
17.
TRACE
ROTATION-Adjusts
trace
to
align
with
the
horizontal
graticule
lines.
DM44
18.
Input
Connectors-Two
banana
jacks
provide
+
(red)
and
COM
(black)
inputs
for
voltage
and
resistance
only.
19.
Probe
Connector-Input
connector
for
the
temperature
probe
.
20.
Readout-Negative
polarity
indication
is
automatic
for
negative
dc
voltage
and
temperature
with
no
polarity
indication
for
positive
measurement. A blinking
display
indicates
overrange.
The
decimal
point
is
position-
ed
by
the
FUNCTION
and
RANGE
controls
for
multimeter
operation
and
by
the
oscilloscope A TIME/DIV
switch
in
the
TIME
or
1/TIME
modes.
21.
RANGE-Selects
from
.2 V to
1.2 kV
dc
in 5 ranges
(1200
volts
is the
maximum
safe
input
in the 1.2 kV
dc
mode);
from 200
ohms
to
20
megohms
in 6 ranges.
22.
FUNCTION-Selects
VOL
TS.
OHMS. TEMP
(QC).
1ITIME.
or
TIME
functions
of
the DM44.
23.
Scale
Factor
Lamps-Two
lamps.
In the
TIME
function
. the
Readout
and Scale
Factor
Lamps
indicate
the
time
difference
between the
two
intensified
zones on the
crt
display. One
lamp
or
the
other
will
light
to
indicate
ms
or
f..lS
.
No
lamp
lit indicates
seconds.
In the
1/TIME
function
the
Readout
and Scale
Factor
Lamps
indicate
the
number
of
measured
intervals per
unit
of
time.
One
lamp
or
the
other
will
light
to
indicate
intervals
per
ms
(1/ms
lamp)
or
intervals
per
f..lS
(1/f..ls
lamp).
No
@
475A/DM44
Operators
7
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Fig.
4.
Trigger
controls,
connectors,
and
indicators.
lamp
lit
indicates
intervals
per
second
. If
the
duration
of
one
event
is
being
measured, the
Readout
and Scale
Factor
Lamps
indicate
frequen
cy.
The
1/
ms
lamp
in-
dicates
kHz, the
1//.1s
lamp
indicates
MHz, and
no
lamp
lit
indicates
Hz.
24.
/.:.;.
TIME-Used
in
conjunction
with
the
DELAY
TIME
POSITION
control
in the
TIME
and
1/TIME
func-
tions. The
/.:.;.
TIME
control
moves
only
the
time-
measurement
point.
The
DELAY
TIME
POSITION
control
moves
both
the
reference
point
and
the
time-
measurement
point.
With
the
time-measurement
point
to
the
left
of
the
reference
point
the
Readout
indicates
a
negative
time
difference
.
NOTE
You
can
modify
your
instrument
to
make
the OELA Y
TIME
POSITION
control
move
only
the
reference
pOint . The
procedure for
making
this
modification
is
located
in the
Maintenance
section
of
the OM44
Service
manual
.
TRIGGER
25.
TRIG
MODE-Determines
the
mode
of
trigger
operation
for
A Sweep
AUTO:
Sweep
is
initiated
by
the
applied
triggersignal.
In the
absence
of
an
adequate
trigger
signal, or
if the
trigger
repetition
rate is less than
about
20
hertz
, the
sweep
free
runs
and
provides a bright
reference
trace
.
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NORM:
Sweep
is
initiated
by
the
applied
trigger
signal.
In
the
absence
of
an
adequate
trigger
signal
, there is
no
trace. When
the
trigger
rate is
too
low
for
AUTO
use
NORM
.
SINGL
SWP : When
this
pushbutton
is
pushed
, the A
Sweep
operates
in the
single
sweep mode.
After a single
sweep
is
displayed,
further
sweeps
cannot
be
presented
until
the
SINGLE
SWP
button
is
again
pushed. It is
useful
when
the
signal
to
be
displayed
is
not
repetitive
or
varies in
amplitude, shape
or
time
causing
an
unstable
conven-
tional
display
. It
can
also
be used
to
photograph
a
nonrepetitive
signal.
26. READY
Lamp-Indicates A Sweep
is
"armed"
and,
upon
receipt
of
an
adequate
trigger
signal,
will
present a
single-sweep
display
.
27.
TRIG
Lamp-Indicates
that A Sweep
is
triggered
and
will
produce a stable
display.
It is
useful
for
setting
up
the
trigger
circuits
when a trigger
signal
is available
without a display
on
the
crt
(for
example,
when
using
ex terna I
triggers).
28. A
TRIG
HOLDOFF-Provides
continuous
control
of
time
between
sweeps.
Allows
triggering
on
aperiodic
signals
(such as
complex
digital
words)
. In the
fully
clockwise
position
(8
ENDS A), A
sweep
is reset at the end
of 8 sweep
to
provide
the fastest
possible
sweep
repetition
rate
for
delayed-sweep
presentations
and
low-repetition
rate signals. Use the A
trigger
controls
for
the best
possible
display
before
using
the A
TRIG
HOLDOFF
control.
29.
COUPLING-Determines
method
used to
couple
signals
to
the
trigger
generator
circuit.
AC: Signals
are
capacitively
coupled
to
the
input
of
the
trigger
generator.
Dc
is
rejected and Signals
below
about
60
Hz
are
attenuated
.
LF REJ:
Signals
are
capacitively
coupled
to
the
input
of
the
trigger
circuit.
Dc
is rejected and
signals
below
about
50 kHz are
attenuated
. It is useful
for
providing
a
stable
display
of
the
high-frequency
components
of
a
complex
waveform
.
HF REJ:
Signals
are
capacitively
coupled
to
the
input
of
the
trigger
circuit. Dc
is rejected and
signals
below
about
60 Hz and above
about
50 kHz are attenuated. It is
useful
for
providing
a stable
display
of
the
low-frequency
components
of a complex
waveform.
DC
: All
components
of a trigger
signal are
coupled
to
the
input
of
the
trigger
circuit.
It is useful
for
providing
a
stable
display
of
low-frequency
or
low-repetition
rate
signals,
except
the
combination
of
the
AL
T (dual trace)
mode
with
the
trigger
SOURCE
switch
in
NORM
.
@
475A/DM44
Operators
9
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Fig. 5. Trigger controls, connectors, and indicators.
30.
SLOPE-Selects
the slope
of
the
trigger
signal
that
I
starts the sweep.
I
+: Sweep can be
triggered
from the
positive-going
I
portion
of a trigger
signal.
-:
Sweep can be
triggered
from the
negative-going
portion
of a trigger
signal.
Correct
SLOPE
setting
is
important
in
obtaining
a
display
when
only a portion
of a cycle
is being
displayed.
31. LEVEL - Selects the
amplitude
point
on the
trigger
signal at
which
the sweep
is
triggered.
It
is
usually
adjusted
for the desired
display
after
trigger
SOURCE,
COUPLING
and SLOPE have been selected.
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32.
SOURCE-Determines
the
source
of
the
trigger
signal
coupled
to
the
input
of
the
trigger
circuit.
NORM:
Trigger
source
is
displayed
signal(s).
It does
not
indicate
time
relationship
between
CH
1 and
CH
2
signals.
However,
stable
triggering
of
non-time-related
signals
usually
can be
obtained
by
setting
VERT
MODE
to
AL
T,
SOURCE
to
NORM
and
COUPLING
to
LF REJ.
Carefully
adjust
LEVEL
for a stable
display.
CH
1: A sample
of
the
signal
available
in
Channel
1 is
used as a
trigger
signal.
CH 2 signal
is
unstable
if it is
not
time-related.
CH
2: A sample
of
the
signal
available
in
Channel 2 is
used as a
trigger
signal.
CH 1 signal
is
unstable
if it is
not
time-related.
LINE
(A
Trigger
circuit
only): A sample
of
the
power-
line
frequency
is used as a
trigger
signal.
It is useful
when
the
input
signal
is
time-related
(mu Itiple
or
submultiple)
to
the
line
frequency
or
when
it is
desirable
to
provide
a
stable
display
of a line-frequency
component
in a
complex
waveform.
EXT:
Signals
connected
to
the
External
Trigger
Input
connectors
are used
for
triggering.
External
signals
must
be
time-related
to
the
displayed
signal
for a stable
display.
It is usefu I
when
the
internal
signal
is
too
small
or
contains
undesired
signals
that
could
cause
unstable
triggering.
It
is
useful
when
operating
in
CHOP
mode.
EXT
-:-
10
(A
Trigger
circuit
only):
External
trigger
signal
is
attenuated
by a factor
of
10.
STARTS
AFTER
DELAY
(8
Trigger
circuit
only):
8
Sweep
runs
immediately
after
the
delay
time
selected
by
the
DELAY-TIME
POSITION
control.
When
making
differential
time
measurements
you
must
use
this
mode
to
obtain
valid
measurements.
On
instruments
equipped
with
a DM44
you
must
use
this
mode
to
obtain
valid
measurements
when
using
the
TIME
or 1 ITIME
functions.
33. External Trigger
Inputs-Input
connectors
for
ex-
ternal
trigger
signals.
@
475A/DM44 Operators
11
Fig.
6.
Horizontal,
calibrator,
and
power
controls,
connectors,
and
indicators.
HORIZONTAL,
CALIBRATOR,
AND
POWER
34a. A
AND B TIME/DIV
AND
DELAY
TIME-A
TIME/DIV
switch
(clear plastic skirt) selects the sweep
rate
of
the A Sweep
circuit
for
A sweep
only
operation
and
selects the basic delay time (to be used
by
the
DELAY-
TIME
POSITION
control)
for
delayed sweep
operation.
B
TIME/DIV
switch
(pullout
and rotate to
unlock)
selects the
sweep rate
for
the B Sweep
circuit
for delayed
sweep
operation
only
. A VAR
control
must be in the
calibrated
detent
for
calibrated
A Sweep rates. When
both
TIME
/DIV
switches are
fully
counterclockwise
to the X-V
position
,
the
horizontal
(X-axis)
display
is the
CH
1 input.
34b.
DM44 A AND B TIME/DIV
AND
DELAY
TIME-
The
controls
operate
in the same
manner
as 37a above.
The A TIME
/DIV
switch
also
controls
the
TIME
lamps and
decimal
point
location
when
the DM44 is in the
TIME
or 1/TIME
MODE
.
35.
FINE/POSITION-Positions
the
display
horizontal-
ly
for
A sweep and B Sweep .
36. X10
MAG-Increases
displayed
sweep rate
by
a
factor
of
10. It extends fastest sweep rate to 1
nanosecond/division.
The
magnified
sweep is the
center
division
of
the
unmagnified
display
(0.5
division
either
side
of
the
center
graticule
line).
12
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37.
VAR-Provides
continuously
variable sweep rates
between
the
calibrated
settings
of
the A
TIME/DIVswitch.
It
extends
the
slowest A Sweep
rate
to
at least 1.25
seconds/division.
The A Sweep
rate is
calibrated
when
the
control
is set
fully
clockwise
to
the
calibrated
detent.
Must
be in the
detent
position
to
make
accu rate
differential
time
measurements.
On
instruments
equipped
with
a DM44
the
VAR
control
must
be in
the
detent
position
to
make
accurate
measurements
in the
TIME
and 1/
TIME
func-
tions
.
38.
UNCAL
Lamp-Indicates
the A
Sweep
rate is
uncalibrated
(VAR
control
out
of
the
calibrated
detent)
.
39.
X10
MAG
Lamp-Indicates
that the X10
magnifier
is on.
40a.
DELAY
TIME
POSITION-Provides
variable
sweep
delay
to
more
than
10
times
the
delay
time
indicated
by
the A
TIME/DIV
switch.
40b.
DM44
DELAY
TIME
POSITION-Operates
in the
same
manner
as
41a. Also,
when
the DM44 is in the
TIME
or
1/TIME
function,
this
control
operates
in
conjunction
with
the!::.
TIME
control.
The
DELAY
TIME
POSITION
control
moves
both
the reference
point
and
the
time-
measurement
pOint. The!::.
TIME
control
moves
only
the
time-measurement
point.
With
the
time-measurement
point
to the
left
of
the
reference
point
the
Readout
indicates a negative time
difference
.
NOTE
You can
modify
your
instrument
to
make
the OELA Y
TIME
POSITION
control
move
only
the reference
point.
The
procedure
for
making
this
modification
is
located
in the
Operating
Information
section
of
the
OM44 Service
manual
.
41..
CALIBRATOR-A
combination
current
loop/square-wave
voltage
output
that
permits
the
operator
to
compensate
voltage
probes
and
check
vertical
gain,
current
probes
and
oscilloscope
operation.
It is
not
intended
to verify time-base
calibration
.
42.
POWER-Turns
instrument
power
on and
off
.
43.
LOW
LINE
Lamp-Indicates
that the
applied
line
voltage
is
below
the
lower
limit
of
the
regulating
range
selected
by
the
Regulating
Range Selector.
44.
HORIZ
DISPLAY-Determines
the
mode
of
opera-
tion
for
the
horizontal
deflection
system .
A:
Horizontal
deflection provided
by A Sweep
at a
sweep
rate
determined
by
the
setting
of
the A
TIME
/DIV
switch.
B sweep is
inoperative
.
@
475A1DM44
Operators
13
MIX:
The
first
part
of
the
horizontal
sweep is displayed
at a rate set
by
the
A TIME/ DIV
switch
and
the
latter
part
of
the sweep at a rate set by the B
TIME/DIV
switch
. Relative
amounts
of
the
display
allocated
to
each
of
the
two
sweep
rates are
determined
by
the
setting
of
the
DELAY-TIME
POSITION
control.
A INTEN:
The
sweep rate
is
determined
by the A
TIME/DIV
switch.
An
intensified
portion
appears
on
the
display
during
the B Sweep time,
which
is
about
10 times
the B
TIMEIDIV
switch
setting. This
switch
position
provides a check
of
the
duration
and
position
of
the B
Sweep (delayed sweep)
with
respect
to
the A Sweep
(delaying
sweep).
B
DL
YO:
The
sweep rate is
determined
by
the B
TIME/DIV
switch
with
the delay
time
determined
by
the
selling
of
the
DELAY
TIME
(A
TIME/DIV)
switch
and the
DELAY-TIME
POSITION
control.
REAR PANEL
45. A
+GATE-Provides a positive-going
rectangular
pulse
coincident
with
the A Sweep time,
which
can be
used to
trigger
the
signal
source
(with
TRIG
MODE
switch
set
to
AUTO).
46. B
+GATE-Provides a positive-going
rectangular
pulse
coincident
with
the B Sweep time,
which
can be
used to
trigger
the signal
source
after
a selected
delay
time,
providing
that A Sweep
is
triggered
internally.
47.
CH
2 VERT
SIGNAL
OUT-Provides a sample
of
the
signal
applied
to
the
CH 2 input
connector
.
48. EXT
Z-AXIS-Permits
intenSity
modulation
of
the
crt
display.
Does
not
affect
display
waveshape. Signals
with
fast rise
and
fall
provide
the
most
abrupt
intensity
change. Signals
must
be
time-related
to
the
display
for
a
stable display. Useful
for
adding
time
markers
in
un-
calibrated
modes
of
operation.
49.
Line
Fuse
Holder-Contains
the
line
fuse and the
regulating
range selector. See
Table 1 for
change
informa-
tion.
50.
Regulating
Range
Selector-Shown
in
Medium
regulating
range. See
Table 1 for
change
information
.
51. PROBE
POWER-Power
source
for
active
probe
systems .
52.
Line
Cord-Makes
the
connection
between the
oscilloscope
and the
power
source. The
cord
may
be
conveniently
stored
by
wrapping
it
around
the
feet on the
rear
panel.
53.
MOD
SLOTS-A
number
in
either
slot
indicates
the
instrument
contains
an
option
or
other
modifications.
LEFT SIDE PANEL
Access
for
externally
available
adjustments
(see Fig. 7).
RIGHT
SIDE PANEL
LINE
VOLTAGE
SELECTOR
SWITCH
(located
on the
right
side)-Selects
either
115 V
or
230 V
nominal
line
voltage.
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CH 1 GAIN
10mV
Fig.
7.
Rear panel and
left
side
panel
controls,
connectors, and
indicators
.
475A/OM44
Operators
(2039)
2163-01
15
BASIC OSCILLOSCOPE DISPLAYS
These
instructions
permit
the
operator
to
obtain
the
most
commonly
used basic
displays.
NORMAL
SWEEP DISPLAY
1.
Set the
controls
as
follows:
VERT
MODE
VOL
TS/DIV
VOLTS/DIV
VAR AC-GND-DC Vertical
POSITION
100
MHz-20
MHz
BW
INVERT
Vertical
CH 1 Position
determined
by
amplitude
of
signal to
be
applied
Calibrated
detent AC Midrange Not
limited
(yellow
band
not
visible)
Button
out
Horizontal
TIME/DIV
Switches
Locked
together
at 1 ms
A
TIME/DIV
VAR
Calibrated
detent
HORIZ
DISPLAY
A
X10
MAG
POSITION
Off
(button
out)
Midrange
Display
INTENSITY
Fully
counterclockwise
Trigger
(Both A and B
If applicable)
SLOPE
LEVEL
SOURCE
COUPLING
TRIG
MODE
(A
only)
A TRIG
HOLDOFF
+
o
NORM AC AUTO NORM
2.
Pull the POWER
switch
(on).
Connect
the
signal
to
the
CH 1 input
connector
.
3.
Adjust
the
INTENSITY
control
for
the
desired
display
brightness.
If the
display
is
not
visible
with
the
INTENSITY
control
at
midrange,
press the
BEAM
FINDER
pushbutton
and
adjust
the CH 1
VOL
TS/DIV
switch
to
reduce
the vertical
display
size.
Center
the
compressed
display
with
the
vertical
and
horizontal
POSITION
con-
trols; release
the
BEAM
FINDER
pushbutton.
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4. Set the
CH 1 VOL
TS/DIV
switch
and
vertical
POSITION
control
to
locate
the
display
within
the
display
area.
5.
Adjust
the A
Trigger
LEVEL
control
for a stable
display
.
6. Set
the A TIME/DIV
switch
and
the
horizontal
POSITION
control
to
locate
the
display
within
the
display
area.
Then
adjust
the
FOCUS
control
as needed.
MAGNIFIED
SWEEP DISPLAY
1.
Obtain a Normal
Sweep
Display.
2.
Adjust
the
horizontal
POSITION
control
to move the
area to
be
magnified
to
with
in the
center
graticule
division
(0.5
division
on
each
side
of
the
center
vertical
graticule
line).
It
may
be
necessary
to
change
the
TIME/DIV
switch
setting
.
3.
Push the X 10
MAG
switch
(on) and
adjust
the
horizontal
POSITION
control
for
precise
positioning
of
the
magnified
display. Divide
the
TIME/DIV
setting
by
10
to
determine
the
magnified
sweep rate.
DELAYED SWEEP DISPLAY
NOTE
Differential
time
measurements
and
measurements
using
the TIME
or 1 ITIME
functions
of
the
DM44
are
invalid
when
the B
Trigger
SOURCE
switch
is
not
set
to
STARTS
AFTER
DELA Y.
1.
Obtain a Normal
Sweep
Display
.
2.
Set the
HORIZ
DISPLAY
switch
to A
INTEN
and the
B
Trigger
SOURCE
switch
to
STARTS
AFTER DELAY.
3.
Pullout
on
the B
TIME/DIV
knob
and
turn
cw
until
the
intensified
zone
is the desired
length. Adjust
the
INTENSITY
control
as needed
to
make
the
intensified
zone
distinguishable
from
the rest
of
the
display. If
your
instrument
is
equipped
with a DM44
, set the
FUNCTION
switch
to a function
other
than
TIME
or
1/TIME
for a single
delayed sweep . Dual delayed
displays
are discussed in
step 6.
@
475A/DM44
Operators 17
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