Tektronix WFM700 Series, Service Manual

Page: 117 / 194

Adjustments
WFM700 Series Waveform Monitors Service Manual
3- 9
This adjustment calibrates the High Definition RGB output amplitude from the
Reference Module.
Video Module Types. WFM700A, WFM700M, and WFM700HD
Requirements. HDVG, 1080-line color bar signal; test oscilloscope
1. Connect the HD video generator to the Video Module under test using a
75
8
cable.
2.
Select the appropriate WFM700 Video Module (1 or 2) and input (A or B).
3. Connect the PIX G/Y output to the 75
8
input of the test oscilloscope using
a 75
8
cable. Use a 75
8
-to-50
8
adapter on the input of the test oscillo-
scope if necessary.
4. Press the CONFIG button.
5. Touch the Video Inputs/Outputs soft key, then Next Menu .
6. Touch the Output Active for HD soft key, then YPbPr .
7. Press the CONFIG button twice to exit menu.
8. Set the test oscilloscope to view the first color bar. The following oscillo-
scope settings normally provide a usable display.
Vertical Scale 100 mV/div
Vertical Position –3.5 div
Horizontal Scale 1 us/div
Horizontal Trigger Position 50%
Trigger Slope Rising edge
Trigger Level 500 mV
9. Adjust R823 for a display of 700 mV on the test oscilloscope. Measure the
amplitude between the black level and the first color bar. See Figure 3--6.
10.
Move the cable from the
PIX G/Y
to the
PIX B/Pb
connector.
11. Set the test oscilloscope to view the signal. The following oscilloscope
settings normally provide a usable display.
Vertical Scale 100 mV/div
Horizontal Scale 10 us/div
Horizontal Trigger Position 10%
Trigger Slope Rising edge
Trigger Level 300 mV
12. Adjust R833 for a display of 700 mV on the test oscilloscope. Measure the
peak-to-peak amplitude of the waveform displayed on the oscilloscope. See
Figure 3--7.
HD RGB Output
Adjustment