TM 11-6625-3025-14/ET 426-AA-MMA-010/E154 VII210/T.O. 33A1-8-902-1-1
5. Select RESOLUTION 1 at the front panel. Compare oscilloscope display to figure 6-25a. In this case, there
should be approximately 133 cycles of black/white pattern as adjusted for the usual 100 tv lines at 4:3 display ratio.
Normally, the burst sequence is adjusted to be 100 tv lines for burst 1,200 tv lines for burst 2, up to 1000 tv lines for burst
10.
6. Set oscilloscope on delayed sweep (0.1 usec per division sweep time), placing the delayed portion of the
sweep on the horizontal line to observe the detail of the resolution waveform. The signal should have approximately 10
nsec rise and fall times with a minimum of overshoot and/or ringing.
7. Adjust the control R1 on the RESOLUTION 1 circuit card (figure 6-26) for content as outlined in table 6-4 (638
nsec at the 675-line scan rate).
8. Using control R43 on the RESOLUTION card, adjust the burst cycle to be symmetrical (50% duty cycle, equal
length of white and black areas). Readjustment of content as outlined in step 5 may be necessary as duty cycle is
balanced.
9. Select each resolution rate in turn, adjusting the control R1 on the appropriate RESOLUTION card to obtain
the resolution density set forth in table 6-4. Select BURST mode in turn for each resolution rate, comparing oscilloscope
display to figure 6-25b. Adjust control R44 of MULTIBURST card to place gray level between burst at 50% of maximum
white level. If the video is adjusted from 0 to 1.0v, the gray level should be at 0.5v. Use delayed or undelayed sweep as
convenient.
10. Select MULTIBURST mode at the front panel. Set oscilloscope sweep to undelayed. Connect the
oscilloscope external sync input to the H drive source. Compare oscilloscope display to figure 6-23a. The waveform
should show bursts of resolution separated by gray level in BURSTS mode, or a pattern whith no separation between
bursts in the CONTINUOUS mode.
11. Adjust the burst width control R30 located on the MULTIBURST card (figure 6-24) to cover the horizontal line
with the resolution pattern as desired. This control was adjusted in step 4, and determines the repetition of the reference
pattern as well as location of bursts in other resolution patterns.
12. Connect the video G output connector to the monitor input to display the resolution patterns. Check that all
bursts are stable and in straight vertical columns. A clear, well defined resolution pattern should be obtained at each
control setting, depending on the quality of the display device.
13. Performance verification of the resolution function is now complete.
6-60
