Trigger - Tektronix 2247A Operator's Manual

Controls, Connectors, and ·Indicators
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2. Sets the B sweep delta delay In TIME measurement mode
when in the ALT or B Horizontal MODES.
3. Sets the width of the Intensified zone for GATED VOLTMETER
and GATED CIT measurements.
4. Changes the setup number or characters In Store/Recall.
NOTE
The reference and delta cursors will only track together as
long as the reference delay plus the delta delay is less than
10 times the
A
SEC/DIV setting (10 horizontal graticule
divisions). Cursors cannot be positioned left of the 1st or
right of the 11th vertical graticule lines.
UNCAL Indicator-Lights when the A AND B SEC/DIV settings are
uncalibrated (variable function In effect).
TRACE SEP Control-Positions the B sweep trace vertically with
respect to the A sweep trace when ALT Horizontal MODE Is selected .
Trigger
Refer to Figure 2-5 for location of Items 32 through 38.
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A/B SELECT Button-Directs the MODE, SOURCE, CPLG, SLOPE ,
and LEVEL controls and Trigger lights (TRIG' D and READY) to either
the A or B Trigger system (A, when lit; B, when not lit).
Either A or B trigger can be selected for any Horizontal MODE :
however, A/8 SELECT is preset to A when A Horizontal MODE I
selected, and B when ALT or B Horizontal MODE Is selected . No
change occurs when switching from B to X-Y Horizontal MODE.
For dual-channel CIT measurements, this button cycles through
three trigger sources: A, B source 1 , and B source 2. The button Is Ht
when A is selected and unlit for either B source. If no menu Is being
displayed, the second-from-top readout line will show which of the
three trigger sources Is selected, along with slope, as shown below :
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2247 A Operators
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FREQ RATIO
A source:
B source 1:
B source 2:
Controls, Connectors, and Indicators
TRIG SELECT: A SLOPE:
t
TRIG SELECT: B chx SLOPE:
t
TRIG SELECT: B chy SLOPE:
t
Chx Is the numerator channel, and chy Is the denominator
channel (CH 1, CH 2, CH 3, CH 4, or ADD may be selected
for either channel) .
t
Is an up-arrow if positive trigger slope
or a down-arrow If negative trigger slope.
""" SEC -+I """ 1 /SEC -+I """ PHASE -+I
(when run
1
in ALT or B horizontal mode)
A source:
B source 1:
B source 2:
PROP DELAY
A source;
B source 1:
~
source. 2:
TRIG SELECT: A SLOPE: 1'
TRIG SELECT: B :sLOPE:
t
TRIG SELECT: B
A
SLOPE:
t
TRIG SELECT: A SLOPE:
t
TRIG SELECT: B START SLOPE:
t
TRIG SELECT: B STOP SLOPE:
t
SLOPE Button-Selects the slope (positive- or negative-going) of
the trigger source signal that triggers either the A sweep, the B
sweep, or the CIT. ( Button lit = positive-going; button.. J10t lit
negative-going. ) '
HOLDOFF Control-Varies holdoff time between the end of one A
sweep and the start of the next A sweep.
The HOLDOFF control can Increase the mi~lmum holdoff time by at
least 10 times. Adjusting this control can Improve triggering stability of
aperiodic signals (i.e. , complex digital waveforms) .
LEVEL Control-Sets the amplitude level on the trigger signal at
which either the A sweep, the B sweep, or the CIT Is triggered. When
a sweep Is triggered, the TRIG' D indicator is lit. During CIT measure-
ments, the TRIG' D Indicator Is unlit for B trigger.
2247A Operators
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