Tektronix 2236, Instruction Manual

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Operating Instructions— 2236 Service
( 2? )
A TRIGGER LEVEL Control— Selects the amplitude
point on the trigger signal at which the sweep is
triggered.
(28J
SLOPE Switches— Select the slope of the signal that
triggers the sweep.
OUT—When button is released out, sweep is trig­
gered from the positive-going slope of the trigger
signal. In WIDTH mode the CTM measures the
positive half cycles of the trigger signals.
IN— When button is pressed in, sweep is triggered
from the negative-going slope of the trigger signal.
In WIDTH mode the CTM measures the negative
half cycles of the trigger signals.
(2 9 ) A SOURCE Switch— Determines the source of the
trigger signal that is coupled to the input of the A Trig­
ger circuit.
INT— Permits triggering on signals that are applied
to the CH 1 OR X & DMM and CH 2 OR Y input
connectors. The source of the internal signal is se­
lected by the A & B INT switch.
LINE— The power-source waveform is the source
of the trigger signal. This trigger source is useful
when vertical input signals are time related (multi­
ple or submultiple) to the frequency of the power-
input source voltage.
EXT— Permits triggering on signals applied to the
EXT INPUT connector.
(3 0 ) A & B INT Switch— Selects the source of the internal
v triggering signal when the A SOURCE switch is set to
INT.
CH 1—The signal applied to the CH 1 OR X &
DMM input connector is the source of the trigger
signal.
VERT MODE— The internal trigger source is deter­
mined by the signals selected for display by the
VERTICAL MODE switches. See Table 2-1 for
VERT MODE trigger source.
CH 2—The signal applied to the CH 2 OR Y input
connector is the source of the trigger signal.
A EXT COUPLING Switch— Determines the method
used to couple external signals to the A TRIGGER
circuit from the EXT INPUT connector.
Table 2-1
VERT MODE Trigger Source
VERTICAL MODE Trigger Source
CH 1
CH 1 OR X & DMM input signal.
CH 2
CH 2 OR Y input signal.
BOTH and ADD Algebraic sum of CH 1 OR X & DMM
and CH 2 OR Y input signals.
BOTH and CHOP
Algebraic sum of CH 1 OR X & DMM
and CH 2 OR Y input signals.
BOTH and ALT Alternates between Channel 1 and
Channel 2 on every other sweep (i.e.
CH 1 OR X & DMM input signal trig­
gers the sweep that displays Channel
1, and CH 2 OR Y input signal triggers
the sweep that displays Channel 2).
AC— Signals above 60 Hz are capacitively coupled
to the input of the A Trigger circuit. Any dc compo­
nents are blocked, and signals below 60 Hz are
attenuated.
DC— All components of the signal are coupled to
the input of the A Trigger circuitry. This position is
useful for displaying low-frequency or low-repe­
tition-rate signals.
DC-MO— External trigger signals are attenuated
by a factor of 10. All components of the signal are
coupled to the input of the A Trigger circuit.
(3 2 ) EXT INPUT Connector— Provides a means of intro­
ducing external signals into the A Trigger circuit
through the A EXT COUPLING switch.
(
33
) B TRIGGER LEVEL Control— Selects the amplitude
point on the trigger signals at which the sweep is trig­
gered. When fully clockwise (B RUNS AFTER DLY),
the B Sweep circuit runs immediately following the de­
lay time selected by the A SEC/DIV and the B DELAY
TIME POSITION control.
VAR HOLDOFF Control— Provides continuous con-
y trol of holdoff time between sweeps. Increases the
holdoff time by at least a factor of 10. This control
improves the ability to trigger on aperiodic signals
(such as complex digital waveforms).
2-7