Operating instructions
TRIGGERING
LEVEL
Control---Selects
a
point
on
the
trigger
signal
where
triggering
occurs
.
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
SWEEP
Mode)
.
TRIG'D
Indicator
Illuminates
when
the
display
is
triggered
.
MODE
Pushbuttons---Selects
the
operating
mode
of
the
triggering
circuit
.
COUPLING
Pushbuttons---Selects
the
method
of
coupling
the
trigger
signal
to
triggering
circuit
.
SOURCE
Selects
source
of
the
trigger
signal
.
SWEEP
POSITION
Control---Provides
horizontal
positioning
.
FINE
Control-----Provides
precise
horizontal
positioning
.
@
MAG
Pushbutton---Selects
magnified
X10
or
unmagnified
sweep
.
@
HOLD
OFF
Control----Permits
hold
off
period
to
be
varied
to
improve
trigger
stability
on
repetitive,
complex
waveforms
.
@)
TIME/DIV
Selector-Selects
the
sweep
rate of
the
sweep
generator
.
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
.
EXTERNAL
TRIGGER
INPUT
EXTTRIG
ATTENUATOR--Selects
attenuation
factor for
external
trigger
signals
.
@
EXTTRIG
IN
Connector---Connector
(BNC
type)
provides
input
for
external
trigger
signals
.
PRETRIGGER
ACQUIRE
CLOCK
EXT
CLOCK
IN
Connector--
Provides
input
for
external
TTL
clock
signals
.
Figure
1-
2
(cont)
.
Front-panel
controls,
connectors,
and
indicators
.
Operating
Instructions---71387
~~
AQS
(acquire
single-shot)
CLOCK/AQR
(acquire
repetitive)---Selects
the
source
of
clock
pulses
from
the
71387
to
the
7854
digitizing
plug-in
oscilloscope (71387
must
be
installed
in
B
horizontal
compartment
of
companion
oscilloscope
mainframe)
.
18
ACQUIRE-STOPDELAY
Control---A
variabledelaygatefunctionthatallowspretriggertimetobevariedincompatible
7000-series
digitizing
oscilloscopes
.
Exact
delay
time
is
displayed
on
oscilloscope
crt
readout
.
278838