Tektronix WFM700 Series, Service Manual

Page: 45 / 194

Performance Verification
WFM700 Series Waveform Monitors Service Manual
2- 13
Stop here for WFM7HD. The Signal Data Path procedure is now finished for the
WFM7HD Input Module. Continue with this check if testing a WFM7A or
WFM7M Input Module.
19. Connect the SD video generator to INPUT B using a 75
8
cable.
20. Set the SD video generator for a 525-format 10-bit shallow ramp matrix
signal.
21. Press the INPUT button and select Input B .
22. Press the WFM button.
23. Touch Pr and Pb to turn off the color difference signals.
NOTE
. The Y component must be on to allow both the Pr and Pb components to
be turned off.
24. CHECK that the steps in the displayed ramps are monotonic (all steps are in
the same direction) and approximately one pixel high. See Figure 2--1.
NOTE
. If the steps are 4 pixels high, it may be that the input signal has only 8
bits of resolution.
25. Press the GAIN button.
26. Touch Gain: 10x .
27. Press the CLR MENU button.
28. CHECK that the steps in the ramps are 0.7 mV to 0.9 mV. (Use the voltage
cursors for this measurement.)
29. Press the WFM button.
30. Touch Pr and Pb to turn these components back on. All components should
be on (Y, Pb, and Pr).
31.
Press the
GAIN
button.
32. Touch Gain: 1x .