Operating instructions

8 . Press the AC COUPLING,
INT SOURCE, and NORM
MODE buttons . Adjust the
LEVEL control for a stable
display .
9 . Press the AUTOMODE button and
adjust the LEVEL
control for a free-running display .
10 . Press the NORM MODE 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 RESET MODE
button is pressed .
13 . Disconnect the
mainframe calibrator signal from the
amplifier unit
input and press the RESET MODE button .
Check for no display and note that the READY indicator
is lit .
14 . Note that one trace occurs
and
that
the READY indi-
cator extinguishes when the
mainframe calibrator signal is
reconnected to the amplifier unit
input
.
GENERAL 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 series
of push buttons . With this arrangement, a
stable display can
usually be obtained by pressing the top
push buttons : P-P
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 in-
adequate, 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 must be made . Refer to the
following discussions
or the instruction
manuals for the associated oscilloscope
mainframeand vertical unit(s) for more information .
Triggering Modes
The MODE push-button switches select the mode in
which
the sweep is triggered .
Operating Instructions-71380
P-P
AUTO . The P-P AUTOMODE provides a triggered
dis-
play at any setting of the LEVEL control whenever an
ade-
quate trigger signal is applied . The range of the
LEVEL
control in
the P-P AUTOMODE is between approximately
10%
and 90% of the peak-to-peak amplitude of the trigger
signal .
The LEVEL control can be set so that the displayed
waveform
starts at any point within this range on either
slope
. The trigger circuits automatically compensate for a
change
in
trigger-signal amplitude . Therefore, if the
LEVEL
control is
set
to
start the waveform display at a certain per-
centage
point on the leading edge of a low-amplitude signal,
it triggers
at the same percentagepoint on the leading
edge
of a
high-amplitude signal if the LEVEL control is not
changed . When the trigger repetition rate is outside the
parameter given
in
the Specification section, or when the
trigger signal is
inadequate, the sweep free runs at the rate
indicated by the TIME/DIV switch to produce a bright
base-line reference trace (TRIG'D light off)
. When an ade-
quate trigger signal is again
applied, the free-running condi-
tion
ends and a triggered display is presented .
The P-P AUTOMODE is particularly useful when
observing
a series of waveforms, since it is not necessary to
reset the
LEVEL control for each observation .
The P-P AUTO
MODE is used for most applications
because of the ease of
obtaining a triggered
display . The AUTO, NORM, and
SINGLE-SWP MODE settings may be used for special
applications
.
AUTO .
The AUTOMODE provides a triggered display
with
the correct setting of the LEVEL control whenever an
adequate trigger signal is applied (see Trigger Level discus-
sions) . 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 sig-
nal is
inadequate, the sweep free runs at the rate indicated
by the
TIME/DIV switch (TRIG'D indicator off) . An ade-
quate 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) .
NORMAL . The NORM MODE provides a
triggered display
with the correct setting of the
LEVEL
control
whenever an
adequate trigger signal is applied .
The TRIG'D light indi-
cates when the display is triggered
.