Adjustment Procedures
5–8 WFM 90 and WFM 91 Service Manual
16. Set the leveled sine wave generator frequency to 50 kHz, and adjust the
generator amplitude for exactly 100 IRE (700 mV PAL) of display.
17. Adjust the peak-to-peak detector Plus amplifier and input control fully
counterclockwise.
18. Note the digital multimeter readout level or the oscilloscope dc level.
19. Set the sine wave generator frequency to 3.58 MHz (4.43 MHz PAL).
20. Adjust the amplitude of the sine wave generator so that the digital multime-
ter readout, or oscilloscope level, matches that noted in step 18.
21. Select X5 FREQ from the Calibration menu, and then select CAL.
22. Adjust the Arrow Buttons for a display amplitude of exactly 100 IRE
(700 mV PAL).
23. Select CAL MENU, and then select SAVE.
24. Select X1 GAIN from the Operating menu, and INT REF from the
Configuration menu.
Perform the following steps to adjust the vector quadrature phase:
1. Replace the signal on the VIDEO IN connector with a 75% color bar signal
from the television signal generator using a 75 W in-line terminator.
2. Select VECTOR display mode.
3. WFM 91 ONLY — Select ALT ON from the Configuration menu.
4. Select QUAD PH from the Calibration menu, select CAL, and then select
RY OFFSET.
5. Adjust the Arrow Buttons for the best center dot overlay.
6. Select QUAD PH.
7. Adjust the Arrow Buttons for the best circle overlay.
8. Select CAL MENU, and then select SAVE.
9. WFM 91 ONLY — Select ALT OFF from the Configuration menu.
Vector Quadrature Phase