Tektronix 2235 - TRIGGER

O perating
Instructions-2235Service
TRIGGER

IN-When pu sh button is presse d in, s w eep is trig-
gere d from the
negative-going
slope of the trigger
R efer to F igure 2-6 for locations of items 25 through 34
.

signal .
TRIGGER Mo de Switches-Three p ush-button
switches that d etermine the trigger mode
for t
he
Α Swee p .
SGL S WP RESET-Press in t he spring-return
p ush bu tton momentarily to ar m t he Α S w ee p ci r -
cuit fo r α si n gle-sweep d isp l ay . T h is mo d e operates
t h e sa m e as N O RM, exce p t only one sweep is d is-
playe d for each trigger signal . Another sweep can-
n ot b e d isplaye d u ntil the SGL S WP RESET P ush
bu tton is momentarily presse d in again to reset the
Α Sweep circuit . This m ode is u seful for d isplaying
and p hotographing either nonrepetiti
υ
e
signals
or
signals that cause u nstable conventional d isp l ays
(e .g ., signals that vary in amplitu d e, shape, or
time) .
Ρ - ΡAUTO-TV LINE-Permits triggering on wave-
forms h aving r epetition r ates of at least 20 Hz an d
television lines . Sweep free-runs in t he absence of
an adequate trigger signal or when the repetition
rate is below 20 H z . The range of the Α T RIGGER
L EVEL control is
r
estricted to the peak-to-peak
range of the trigger signal .
N ORM-Sweep is initiate d
when
an adequate
trig-
ger signal is applied . In the absence of
α trigger
signal, no baseline trace wil l b e present .
ι ι
FA
:
4207-07
F igure 2-6 . Trigger controls, connector, and indicator .
TV FIELD-Press in both Ρ - Ρ AUTO and N ORM

29 Α SOURCE Switch-Determines the source of the
push bu ttons . P ermits triggering on television
field

trigger signal that is coupled to the inp u t of the Α Trig-
signals .

ger circuit .
ΙΝΤ - P ermits triggering on signals that a r e applie d
T RIG'D READY In d icator-T he L ED i l luminates
when

to the CH 1 OR Χa nd C H 2 OR Υ input c οηπ e ε -
eit h er the Ρ - Ρ AUTO or the NORM Trigger Mo de is

tors . The source of t he internal signal is selected by
se l ecte d to indicate t h at the Α Sweep is
triggered

t he Α & Β ΙΝΤ switch .
(TRIG'D) . When t he SG L S WP
RESET button is
mo-
mentarily pressed in, the LED illuminates to indicate

L INE-Selects the p owe r -source waveform as the
t h at the Α Trigger circuit is armed
(READY) for
α
sin-

source of the trigger signal . This trigger source is
gle-sweep display .

useful when
vertical-input
signals are time relate d
(multiple or submultiple) to the frequency of the
power-source voltage-
Α TRIGGER LEVEL Control-Selects the amplitude
p oint on the trigger signal at
which t
he
sweep is

ΕΧΤ -Permits triggering on signals applie d to t he
triggere d .

ΕΧΤ I N PUT connector .
28 SLOPE S w itches-Select the slope of
the signal that

30 Α&Β ΙΝΤ Switch-Se l ects the source of the inter n al
triggers the sweep .

trigger signal when the Α SO U RCE switch is set to
INT .
OUT-W
h
en push button
is re l ease d out, sweep is
triggere d f rom t he positive-going slo pe of
the trig-

CH 1-The signal applied to the CH 1 OR Χ input
ger signal .

connector is the source of the trigger signal
.