Performance Verification
4–10 WFM 90 and WFM 91 Service Manual
17. Adjust the peak-to-peak detector Plus amplifier and input control fully
counterclockwise.
18. Adjust the sine wave generator for a display amplitude of 100 IRE (700 mV
PAL).
19. Note the digital multimeter readout level or the oscilloscope dc level.
20. Set the sine wave generator frequency to 3.58 MHz (4.43 MHz PAL).
21. Adjust the sine wave generator amplitude for exactly 100 IRE (700 mV
PAL) of display.
22. Check that the digital multimeter readout level, or the oscilloscope dc level,
is within "7 mV of the reading noted in step 19.
23. Set the sine wave generator frequency to 6 MHz.
24. Adjust the sine wave generator amplitude for exactly 100 IRE (700 mV
PAL) of display.
25. Check that the digital multimeter readout level, or the oscilloscope dc level,
is within "7 mV of the reading noted in step 19.
26. Select X1 GAIN from the Operating menu.
27. Remove the dual-input coupler from the instrument.
28. Connect the function generator output to the VIDEO IN connector using a
X10 (75 W) attenuator.
29. Select 1H SWEEP from the Operating menu.
30. Enter the Configuration menu and select the INPUT category. Select
EXT REF and SLOW DC REST.
31. Set the function generator to output a 60 Hz (50 Hz PAL) sine wave with a
display amplitude of 100 IRE (700 mV PAL) on the WFM90 or WFM 91
Handheld Waveform, Vector, Picture, and Audio Monitor.
32. Connect a black burst signal to the REF IN connector. Do not terminate the
input.
33. Check that the display amplitude is w80 IRE (560 mV PAL).
34. Select FAST DC REST.
35. Check that the display amplitude is v10 IRE (70 mV PAL).
36. Select INT REF and SLOW DC REST from the Configuration menu.
37. Remove all input signals from the WFM 90 or WFM 91 Handheld Wave-
form, Vector, Picture, and Audio Monitor.