Adjustment Procedures:Analog Section
WFM90D and WFM91D ServiceManual 5-7
VerticalGain and X5 Gain Registration
Perform thesesteps to adjust the vertical gain and X5 gain registration:
1. Replace the signal on the VIDEO IN connectorwith the output from the
VAC.Do not terminate the input.
2. Set the VACfor a 999.9 mV output with all of the buttons out except +LUM
and NTSC (PALbutton for the WFM91D).
3. Select X1 GAIN from the Calibration menu, and thenselect CAL.
4. Adjust the arrowbuttons for a display amplitude of exactly 140 IRE
(1000 mV PAL).
5. Select CAL MENU, and then select SAVE.
6. Set the VACfor a 199.9 mV output.
7. Select X5 GAIN from the Operating menu.
8. Select X5 GAIN from the Calibration menu, and thenselect CAL.
9. Adjust the arrowbuttons for a display amplitude of exactly 140 IRE
(1000 mV PAL).
10. Select CAL MENU, and then select SAVE.
11. Replace the signal on the VIDEO IN connector with a 75% color bar signal
from the television signal generator,using a 75 Ωin-line termination.
12. Select X5 POS from the Calibration menu, and then selectCAL.
13. Select X1 GAIN, and then position the signal baseline to thegraticule
baseline.
14. Select X5 GAIN from the Calibration menu, and thenselect X5 POS.
15. Use the arrowbuttons to return the signal baseline to the graticule baseline.
16. Select X1 GAIN from the Calibration menu.
17. Select CAL MENU, and then select SAVE.
18. Remove the signal and termination fromthe VIDEO IN connector.
Frequency Response
Perform thesesteps to adjust the frequencyresponse:
1. Connect a 50 Ωprecision cablefrom the leveled sine wave generator output
to the dual-input coupler using a 50 Ω-to-75Ωminimum loss attenuator.