Operating Instructions-2225 Service
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Variable SEClDlV Control-Continuously
varies the uncalibrated sweep time per
division to at least 2.5 times the calibrated
time per division set by the
SECIDIV switch.
Full ccw rotation of the variable (CAL) knob
increases the slowest sweep time per division
to at least two seconds.
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Horizontal MAG Switch-Sets the amount of
horizontal magnification to X5,
X10, or X50
when the Horizontal MODE switch is set to
either ALT or MAG.
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GND Connector (h)-provides an auxiliary
ground connection directly to the instrument
chassis via a banana-tip jack.
PROBE ADJUST Terminal-Provides an
approximately 0.5-V, negative-going
,
square-wave signal (at about 1 kHz) for use in
compensating voltage probes and checking
the vertical deflection system. The PROBE
ADJUST output signal is not intended as a
reference for checking either the vertical or
the horizontal accuracy of the instrument.
TRIGGER
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Trigger SLOPE Switch-Selects either the
positive
(I)
or negative
(I)
slope of the
trigger signal to start the sweep.
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Trigger LEVEL Control-Selects the ampli-
tude point on the trigger signal that produces
triggering.
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TRIG'DIREADY Indicator-A dual-function
LED indicator. In P-P AUTO and NORM trigger
modes, the indicator is turned on when
triggering occurs. In SGL SWP trigger mode,
the indicator turns on when the trigger circuit
is armed, awaiting a triggering event; it turns
off again as soon as the single sweep is
triggered.
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Trigger MODE Switch-Determines the sweep
triggering mode.
P-P AUTO-TV LINE-Triggering occurs on
trigger signals having adequate amplitude
and a repetition rate of about 20 Hz or
faster. In the absence of a proper trigger
signal, an autotrigger is generated, and the
sweep freeruns.
NORM-Permits triggering at all sweep
rates (an autotrigger is not generated in the
absence of an adequate trigger signal).
NORM trigger mode is especially useful for
low-frequency and low-repetition-rate
signals.
TV FIELD-Permits stable triggering on a
television field signal (vertical sync). In the
absence of an adequate trigger signal, the
sweep freeruns. The instrument otherwise
behaves as in
P-P
AUTO.
SGL SWP-Selects single sweep-
operation.
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SGL SWP RESET Button-Arms the trigger
circuit for a single sweep. Triggering require-
ments are the same as in NORM trigger
mode. After the completion of a triggered
sweep, pressing in the SGL SWP RESET
button rearms the trigger circuitry to accept
the next triggering event.
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HOLDOFF Control-Adjusts the variable
holdoff time. Variable holdoff starts at the end
of the sweep.
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Trigger SOURCE Switches-Determine the
source of the internal and external trigger
signal for the trigger generator circuits.
CH 1-Trigger signal is obtained from the
CH
1
OR
X
input connector.
VERT MODE-Trigger signals are auto-
matically obtained alternately from the CH
1
OR
X and CH 2
OR
Y
input signals in ALT
vertical mode. In CHOP vertical mode, the
trigger signal source is the sum of the
Channel
1
and Channel 2 input signals.
CH 2-Trigger signal is obtained from the
CH 2
OR
Y
input. The CH 2 INVERT switch
also inverts the polarity of the internal
Channel 2 trigger signal when the Channel 2
display is inverted.
EXT-Selects external trigger source. The
actual form these triggers take is selected
by the second SOURCE switch.
Scans
by
ARTEK
MEDU
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