TM 11-6625-3025-14/ET426-AA-MMA-010/E154 VII210/T.O. 33A1-8-902-1-1
4. Oscilloscope sweep rate should show the entire horizontal line when using horizontal related sync and
observations. Set oscilloscope channel 1 input amplitude sensitivity at 0.5v per division.
5.
Compare the oscilloscope display to figure 6-21A.
6. The length of scanning line in which the gray scale is presented, is adjusted by using the control R1, (step 1)
located on the GRAY SCALE CONTROL card, figure 6-22. This should be adjusted if the gray scale does not extend
across the horizontal line which would show a large margin of white at the right side of the display or if the gray scale is
incomplete through the horizontal line period.
7. Check that there is a proper staircase presentation with steps of correct proportion. If there is any deviation
from this figure, adjustment should be performed as outlined below. The procedure is written for generation of a linear
gray scale; if other than a linear stairstep presentation is desired, a procedure should be followed which will obtain that
presentation.
8. Using the VIDEO LEVEL control, adjust the black-to-white video amplitude (not including the blanking
pedestal) to 0.9v peak-to-peak when properly terminated.
9. Starting with the control R8 on the GRAY SCALE card, adjust the level of the top step of the gray scale down
from white by 0.1v. Using the next control (R7) on this card, adjust the second step 0.1v down from the previous step.
Moving to the next control (R6), adjust the third step and then the fourth step using the next control (R5) on the card. In
the same manner, adjust all controls on the GRAY SCALE card until all eight steps between black and white have been
adjusted to 0.1v. The horizontal and vertical positions of the oscilloscope display may be shifted to place the step under
adjustment at the center graticule lines for convenience in adjustment of the gray scale levels. There should be gray scale
at each minor division for a linear gray scale.
10. Connect the oscilloscope external sync input to the V drive source. Set oscilloscope sweep rate to 2 msec
per division. Compare oscilloscope display to figure 6-21b.
11. Connect the video output connector to the monitor input to display the gray scale pattern. A clear, well
defined gray scale pattern with all lines straight should be obtained, depending on the quality of the display device.
12. Performance verification of the gray scale function is now complete.
6-53
