Trigger - Tektronix 2235 Instruction Manual

Preparation for Use—2235 Operators
A and B SEC/DIV Variable Control—Provides contin
uously variable, uncalibrated A Sweep speeds to at
least 2.5 times the calibrated setting. It extends the
slowest sweep speed to at least 1.25 s per division.
(2^ X10 Magnifier Switch—To increase displayed sweep
speed by a factor of 10, pull out the A and B SEC/
DIV Variable knob. The fastest sweep speed can be
extended to 5 ns per division. Push in the A and B
SEC/DIV Variable knobto regain the XI sweep speed.
HORIZONTAL MODE Switch—This three-position
switch determines the mode of operation for the
horizontal deflection system.
A—Horizontal deflection is provided by the A
Sweep generator at a sweep speed determined by
the A SEC/DIV switch setting.
ALT—Alternates the horizontal displays between
the A Sweep (with an intensified zone) and the
B Delayed Sweep. The A Sweep speed is deter
mined by the setting of the A SEC/DIV switch.
The B Sweep speed and the length of the inten
sified zone on the A Sweep are both determined
by the B SEC/DIV switch setting.
B—Horizontal deflection is provided by the B
Sweep generator at a sweep speed determined by
the B SEC/DIV switch setting. The start of the B
Sweep is delayed from the start of the A Sweep by
a time determined by the settings of both the A
SEC/DIV switch and the B DELAY TIME
POSITION control.
(2^ A/B SWP SEP Control—Vertically positions the B
Sweep trace with respect to the A Sweep trace when
ALT HOP IZONTAL MODE is selected.
B DELAY TIME POSITION Control-Selects the
amount of delay time between the start of the A
Sweep and the start of the B Sweep. Delay time is
variable from 0.5 times to 10 times the A SEC/DIV
switch setting.
(2^ POSITION Control—Horizontally positions both the
A Sweep and the B Sweep displays and horizontally
positions X-axis in the X-Y mode.
TRIGGER
Refer to Figure 2-6 for locations of items 25 through 34.
(2^ A TRIGGER Mode Switches—Three push-button
switches that determine the trigger mode for the A
Sweep.
SGL SWP RESET—Press in the spring-return push
button momentarily to arm the A Sweep circuit
for a single-sweep display. This mode operates the
same as NORM, except only one sweep is dis
played for each trigger signal. Another sweep
cannot be displayed until the SGL SWP RESET
push button is momentarily pressed in again to
reset the A Sweep circuit. This mode is useful for
displaying and photographing either nonrepetitive
signals or signals that cause unstable conventional
displays (e.g., signals that vary in amplitude, shape,
or time).
P-P AUTO-TV LINE—Permits triggering on wave
forms having repetition rates of at least 20 Hz and
television lines. Sweep free-runs in the absence of
an adequate trigger signal or when the repetition
rate is below 20 Hz. The range of the A TRIGGER
LEVEL control is restricted to the peak-to-peak
range of the trigger signal.
TRIGGER
LEVEL
A TRIGGER
SGL SWP R.PAUTOt NORM
EXT INPUT
4207-07
Figure 2-6. Trigger controls, connector, and indicator.
2-6