Operating instructions

71387 Instruction
VIII
Flit
Poernow
aI ~' IAN
ACQUIRE
STOP
DELAY
71387 FEATURES
TRIGGERING
Yoaf
F
-P AU T0
AUTO

AC LF W
*OW

AC IF KJ
MAG
II '~ XI
O~IrT
COMING
OC
HOLD
OFF
EXT
CLOCK IN

SWIM
CAL
Its IIh
USX)

II
+
1
OUT+1!
EXT TRIG
IN
y

S 2f4y
2788-1
The 71387
Time-Base unit Pretrigger
Acquire Clock provides calibrated sweep rates from 5 seconds to
10 nanoseconds and triggering to 400
megahertz for 7000-Series
Oscilloscopes . A X10 Magnifier increases each sweep rate by a factor of 10
and a VARIABLE TIME/ DIV
control
provides continuously-variable
sweep rates between calibrated steps . Variable holdoff and
alphanumeric readout are provided . Also,
when
operating in the AUTO TRIGGERING
MODE, a bright baseline trace is displayed in the absence of a
trigger signal . The 7887 can be
operated
as an
independent time base or
as a delayed-sweep unit with a companion delaying time-base
unit . Sweep mode is determined by
the
companion delaying time base .
The 71387 also
features an internally-generated clock and an
external clock input for sequential single sweep
acquisition when operating in a
7000-series
digitizing oscilloscope . The frequency
range
of
the internally generated clock is 20 .48
mHz (millihertz) to 20 .48 MHz as
determined
by the TIME/DIV, X10MAG, and
INT
_
1000 switches . Also, an ACQUIRE-STOP DELAY
function varies delay pickoff, and
therefore
pretrigger time, in compatible
digitizing plug-in oscilloscopes . The portion of the oscilloscope
real-time display between the
triggering
event and the end of delay
time is intensified . The exact delay time is displayed on
the crt readout .