Operating instructions

14 . Note that
one trace occurs and that the READY
indicator extinguishes when the
mainframe calibrator
signal is reconnected
to
the
amplifier unit input .
PRETRIGGER ACQUIRE
CLOCK
FUNCTIONS
NOTE
The following procedure must be performed
with the 71387 installed in the B horizontal
compartment of a Tektronix 7854
Oscilloscope .
1 . Install the 71387 in the
7854 Oscilloscope B horizontal
compartment and install an amplifier unit in
the
mainframe left vertical compartment . Turn
on
oscilloscope power . See Tektronix 7854 Oscilloscope
Operators Manual for detailed operating information .
2 . Set the time-base unit controls as follows
:
SLOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (+)
MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . AUTO
COUPLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AC
SOURCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INT
POSITION . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Midrange
TIME/DIV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
ms
VARIABLE . . . . . . . . . . . . . . . . . . Calibrated (CAL IN)
HOLDOFF . . . . . . . . . . . MIN (fully counterclockwise)
MAG . . . . . . . . . . . . . . . . . . . . . . . . . . . X1 (pushed in)
AQS CLOCK/AQR
. . . . . . . . . . .
. . . . . . . . . INTERNAL
ACQUIRE STOP DELAY . . . . . . . . . . . . . . . . Midrange
3 . Set the 7854 vertical and horizontal modes to display
the plug-in units and set WFM ACQUISITION to SCOPE .
Set the intensity and focus for a well-defined, intensified
display .
4 .
Connect
the 0 .4-volt, 1-kilohertz signal
from the
mainframe calibrator
to
the amplifier
unit
input
.
5 .
Set
the
amplifier
unit deflection factor for 4 divisions
of display .
6 . Set the TRIGGERING MODE to NORM and adjust the
LEVEL control for a stable display (TRIG'D light on) .
7 . Rotate the ACQUIRE-STOP DELAY control fully
counterclockwise . Notice that delay-time readout (located
in
the lower
right-hand
corner of the crt) is near 0 .2 ms .
(Zero delay time means that the acquired signal occurred
prior
to the triggering event .)
8 . Rotate the ACQUIRE-STOP DELAY control
until the
delay-time readout is approximately 4 ms . Notice that the
first four divisions of squarewave display are intensified .
The
4 ms intensified display relates to four divisions of
post-trigger in
the subsequent single-sweep display .
Therefore, the remaining 6 divisions in the subsequent
display
would
be
pre-trigger
(see Fig . 1-3) .
Operating Instructions-71387
NOTE
Four divisions
of
intensified
display at 1
msldiv relates to delay-time
readout of
approximately 4 ms .
9 . Set the amplifier unit input
coupling switch to off or
ground . Set the 71387
to SINGLE SWEEP MODE and
press the RESET
pushbutton so that READY light is
on
.
10 . Set the
7854 to Stored
CRT
Display and then to
Acquire Single-Shot Waveform Acquisition
(AQS) .
INTENSIFIED
ZONE
POST-TRIGGER

SCOPE (REAL-TIME) MODE
TIME

SWEEP SPEED
r

\1
MEMO
M
Emma
ENMEM
MOMMM
MEMEM
ME
V
_TRIGGER
POINT
ACQUIRE
.
STO P
Nofr
ACQUIRE-STOP DELAY TIME-L .
- 1 -- (POST-TRIGGER TIME)
(A) 7854 REAL-TIME DISPLAY (SCOPE MODE)
PRE-TRIGGER
TIME IN

POST
TRIGGER
THE 71387 INTERNAL

TIME
AQS CLOCK
MODE
OPW "
V2R~ " 1 " w
SINGLE SWEEP
TRIGGER POINT
(B) 7854 STORED SINGLE SWEEP
DISPLAY .
2788 6
Figure 1-3 . Single Sweep Acquisition .