Motorola R-2001A Service Manual page 67

5-107. CRT intensity Bias
1. Select the Scope DC Display and the Ext Horiz. Input mod» Set the Intensity Control fully counter
clockwise.
Do not let a dot stay in one place on the CRT screen for more than 30 seconds as a
permanent burn in the phosphor will occur.
2. Adjust the Intensity Bias potentiometer (Figure 5-13) until a dot appears on the screen. (The Vertical
and Horizontal Position Control on the front panel may have to be used to bring the dot on to the
screen.) Then back off the Intensity Bias potentiometer until the dot just disappears.
5-108. CRT Intensity Balance
1. Select the Scope DC Display and the 1 mSec/Div Horizontal Sweep rate on the R2001A. Set the
Horizontal Timebase Veriner to the Cal position and adjust the Intensity Control for a barely visible
horizontal line on the CRT.
2. Adjust the Intensity Balance potentiometer (Figure 5-13) for uniform intensity of the horizontal trace
from left to right. The Balance potentiometer affects the intensity on the left side of the trace.
5-109. CRT Horizontal Centering
1. Select the Gen/Mon Mtr Display on the R2001A. Adjust the Intensity Control for a comfortable viewing
brightness.
2. With the Test Point Shorting Jumper connect TP1 of the Scope Amplifier Board (Figure 5-13) to
chassis ground.
3. Adj ust the Horizontal Position Potentiometer (Figure 5-13) so that the vertical trace on the CRT screen
passes through the graticule center point.
4. Remove the jumper from TP1.
5-110. CRT Vertical Centering
1. Select the Gen/Mon Mtr Display on the R2001A. Adjust the Intensity Control for comfortable viewing
brightness.
2. With the Test Point Shorting Jumper connect TP4 of the Scope Amplifier Board (Figure 5-13) to
chassis ground.
3. Adjust the Vertical Position Potentiometer (Figure 5-13) so that the horizontal trace on the CRT screen
passes through the graticule center point.
5-111. CRT Trace Rotation
1. Select the Gen/Mon Mtr Display on the R2001A. Adjust the Intensity Control for a comfortable viewing
brightness.
2. Adjust the Trace Rotation Potentiometer for a properly rotated CRT display.
CAUTION
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