6-15
Figure 6-17.—Effects of FOCUS and ASTIG (astigmatism) controls.
TRACE ROTATION Control
The TRACE ROTATION control (figure 6-16) allows for minor adjustments of the horizontal
portion of the trace so that you can align it with the horizontal lines on the graticule.
BEAM FINDER Control
Occasionally, the trace will actually be located off the CRT (up or down or to the left or right)
because of the orientation of the deflection plates. When pushed, the BEAM FINDER (figure 6-16) pulls
the beam onto the screen so that you can use the horizontal and vertical POSITION controls to center the
spot.
Horizontal and Vertical POSITION Controls
The horizontal and vertical POSITION controls (figure 6-16) are used to position the trace. Because
the graticule is often drawn to represent a graph, some oscilloscopes have the positioning controls labeled
to correspond to the X and Y axes of the graph. The X axis represents horizontal movement; the Y axis
represents the vertical movement. Figure 6-18 shows the effects of positioning controls on the trace.
