Heathkit IO-4550 - Page 14

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12
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EXAMPLE 2
Normal or Automatic Triggering
The AUTO mode (automatic triggering) provides a base or
reference line without the presence of a vertical input signal.
This line is used as a reference point, especially for DC
measurements.
With the controls and switches set as they were at the
conclusion of Example 1, and with a waveform of the 1 kHz
sine wave signal on the CRT, push in the LEVEL control to
the AUTO position. The trace will appear as one complete
cycle.
Make sure the TIME/CM switch is in the .1 mS position and
the VARIABLE control is fully clockwise and pushed in.
Figure 5
Slowly increase your signal generator frequency to 2 kHz
and note that the display on the CRT remains locked in. At
2 kHz, two complete cycles of the input signal will be
displayed as in Figure 5.
XAMPLE 3
Trace Operation
source: Sine wave — square wave generator capable of
e. simultaneous, sine wave and square wave output, 1
‘ne wave signal to the Y1 INPUT and the
| to the Y2 INPUT.
| Y2 VOLTS/CM switches at 1V and
AC; then set the following switches
1, plus (+)
Cc
enter
of
rotation
and
shed in (AUTO)
mS
Adjust the Y1 and Y2 POSITION controls so the two
waveforms are separated on the CRT. The display will be
similar to that shown in Figure 6.
tH |
LN | | TANT
APNOACNC
| | RYT TT RY
| ft | |
aa ey
mms en a
ia a
le Gr ee ees
a es
NOTE: Either channel can be turned off by turning the
respective POSITION control fully counterclockwise to the
detent (OFF) position.
Figure 6
Turn the LEVEL control so triggering occurs at the peak of
the sine wave as in Figure 7. Note that this is at the
midpoint of the positive portion of the square wave.
ea pt aA Sd
NER ANEEE.
Figure 7
Return the LEVEL control to the center of rotation and the
waveforms will again appear in their generated phase
relationship.
EXAMPLE 4
X-Y Mode Operation
With the TIME/CM switch in the X-Y position, and the
TRIG in Y2, Y¥2 (Y) signals produce vertical deflection while
Y1 (X) signals produce horizontal deflection. In the X-Y
mode, the Y1 (X) controls and switches affect the
horizontal display. Adjust the HORIZ POS control so the
Y1 (X) POSITION control will move the spot off the screen
in both directions.
Trapezoidal and Lissajous patterns that are useful in
studying modulation characteristics, and frequency and
phase comparisons, result from applying separate signals to
the Y1 (X) and Y2 (Y) inputs in the X-Y mode.
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