PULL (—) SLOPE:
Two-position push-pull switch. The “in” position
selects a positive-going slope and the “out” position
selects a negative-going slope as triggering point for
main sweep.
27.
EXTernal TRIGger Jack. External trigger input for
single- and dual-trace operation.
DIGITAL STORAGE CONTROLS
28.
STORAGE/ANALOG Pushbutton. When released,
scope is in ANALOG mode. When engaged, scope is
in digital STORAGE mode. In ANALOG mode, all
digital mode controls (29–38) are disabled. In STOR-
AGE mode, all digital mode controls (29–38) are
enabled.
In STORAGE mode with all digital mode controls
(29–38) released, scope is in REFRESH mode of
storage, in which it updates the stored waveform each
time an adequate trigger signal is received (if the
previous update has been completed). REFRESH
mode is applicable at all TIME/DIV settings.
29. SAVE CH2 Pushbutton. Engaging this switch
freezes and stores the channel 2 trace immediately.
The channel 2 display and memory cannot be updated
until this switch is released.
30. SAVE ALL Pushbutton. Engaging this switch
freezes and stores the channel 1 and channel 2 traces
immediately. The display and memory cannot be up-
dated until this switch is released.
31.
SLOW X100 Pushbutton. Engaging this switch ex-
pands the time base settings of 10 ms/div to 0.5 S/div
by a factor of 100 to become settings of 1 sec/div to
50 sec/div. Time base settings are normal when this
switch is released.
32.
ROLL Pushbutton. Engaging this switch selects the
ROLL mode of operation, in which the trace moves
across the CRT from right to left like a strip chart
recorder (opposite of conventional oscilloscope opera-
tion) and the display is continuously updated. This
update takes place even in the absence of any trigger
signal. The rolling speed equals the TIME/DIV set-
ting (and SLOW X100 if engaged). ROLL mode is
applicable only at time base settings of 10 ms/div to
0.5 S/div.
33.
SINGLE Pushbutton. Engaging this switch enables
the single sweep mode of digital storage operation, in
which the memory is filled in a single sweep and
continuously displayed. Single sweep mode is appli-
cable for all “real time” settings of the TIME/DIV
control, that is, 20
µ
s/div and slower.
34.
RESET Pushbutton. With the SINGLE switch en-
gaged, this switch readies the scope for single sweep
operation. A suitable trigger signal arriving after press-
ing the RESET switch initiates the single sweep.
35.
READY Indicator. Lights when the RESET switch
readies the scope for single sweep, and goes out when
trigger signal occurs.
36.
PRE-TRIGGER Pushbuttons. Selects post-trigger
or pre-trigger storage conditions. In post-trigger con-
dition (0% pre-trigger), the entire stored waveform
occurs after the trigger. The trigger point is at the
extreme left of the display, as in a conventional analog
oscilloscope display. In pre-trigger conditions, a por-
tion of the waveform occurring before the trigger is
displayed. Pre-trigger selections of 25%, 50%, and
75% are selectable. For 0% pre-trigger, release both
PRE-TRIGGER pushbuttons. For 25% pre-trigger,
engage the left pushbutton. For 50% pre-trigger, en-
gage the right pushbutton. For 75% pre-trigger, engage
both pushbuttons. Pre-trigger operation is applicable
only to single sweep operation, not to ROLL or
REFRESH modes.
37.
PLOT Pushbutton. When engaged, this switch acti-
vates the PLOT mode. Output is available at the CH1
OUTPUT, CH2 OUTPUT, and PEN DOWN jacks
on the rear of the scope. At the appropriate time, the
PEN DOWN output goes TTL low to permit plotting
on an analog plotter or strip chart recorder. The PLOT
mode is applicable only when the SAVE ALL push-
button is engaged.
38.
PEN DOWN Indicator. In the PLOT mode, this
indicator lights when the PEN DOWN output on the
rear panel is TTL low.
REAR PANEL CONTROLS (see Fig. 2)
39.
Fuse Holder/Line Voltage Selector. Contains fuse
and selects line voltage.
40.
Power Cord Receptacle.
41.
CH1 OUTPUT Jack. Supplies channel 1 digital stor-
age contents for use with an analog plotter.
42.
CH2 OUTPUT Jack. Supplies channel 2 digital stor-
age contents for use with an analog plotter.
43.
PEN DOWN Output Jack. TTL open collector out-
put to raise and lower plotter pen. Plotter information
is output at the CH1 OUTPUT and CH2 OUTPUT
jacks, starting at each positive and negative transition
of PEN DOWN. The TIME/DIV switch sets the period
of this output, except plotting is at 10x the TIME/DIV
setting.
44.
Y OUTPUT Jack. Output terminal where sample of
channel 2 analog signal is available. Amplitude of
output is 50 millivolts per division of vertical deflec-
tion seen on CRT when terminated into 50 ohms.
Output impedance is 50 ohms.
CONTROLS AND INDICATORS
10