Trigger; Horizontal Controls - Tektronix 2215A Instruction Manual

22
( ) HORIZONTAL MODE Switch— 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 determined
by the setting of the A SEC/DIV switch. The B
Sweep speed and the length of the intensified 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 POSI­
TION control.
(2 3 ) A/B SWP SEP Control— Vertically positions the B
Sweep trace with respect to the A Sweep trace when
ALT HORIZONTAL MODE is selected.
(2 4 ) B DELAY TIME POSITION Control— Selects the
amount of delay time between the start of the A
Figure 2-5. Horizontal controls.
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.
Refer to Figure 2-6 for location of items 25 through 34.
(25J A TRIGGER Mode Switches— Three-section switch
that determines the trigger mode for the A Sweep.
SGL SWP RESET— Press in the spring-return but­
ton momentarily to arm the A Trigger circuit for a
single-sweep display. In this mode, the trigger sys­
tem operates the same as NORM, except only one
sweep is displayed for each trigger signal. Another
sweep cannot be displayed until the SGL SWP
RESET button is momentarily pressed in again to
reset the A Trigger 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 and division lines having repetition rates of
at least 20 Hz. 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
Operating Instructions— 2215A Service

TRIGGER

2-5