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Performance Verification: Analog Section
WFM90D and WFM91D Service Manual
4-7
Vertical Gain and Vertical Magnifier Registration
This procedure verifies the following requirement:
1 Volt Full Scale: 1 V input displayed within 1% of 140 IRE (1.00 V PAL).
X5 Gain: Gain accuracy within 5% with 1 V input signal. X5 Gain Registration:
≤1 major division of vertical shift from baseline between unmagnified and
magnified signal.
1. Set the multiburst generator controls to Composite and Multiburst.
2. Position the signal baseline to the graticule baseline, and then select
X5 GAIN from the Operating menu.
3. Check that the signal baseline is within ᐔ1 major division of the graticule
baseline.
4. Select X1 GAIN from the Operating menu.
5. Remove the signal and termination from the VIDE O IN connector.
6. Connect the output of the VAC to the VIDEO IN connector. Do not
terminate the input.
7. Set the VAC for a 999. 9 mV output, with all of the buttons out except for
+LUM and NTSC (PAL button for the WFM 91).
8. Check for a display amplitude of 140 IRE ᐔ1.4 IRE (1000 mV ᐔ10 mV
PAL).
9. Set the VAC for a 199.9 mV output.
10. Select X5 GAIN from the Operating menu.
11. Check for a display amplitude of 140 IRE ᐔ5 IRE (1000 mV ᐔ50 mV
PAL).
12. Select X1 GAIN from the Operating menu.
Variable Gain Range and Vertical Position Range
This procedure verifies the following requirement:
Variable Gain Range: Input signals between 0.8 V and 2 V can be adjusted to
140 IRE (1.0 V) display. 160 mV and 400 mV for X5 Gain. Vertical Position
Range: 1 V signal can be positioned so that peak white and sync tip can be
placed at blanking level, with the DC Restorer Clamp on, regardless of gain
setting.
1. Set the VAC for a 999.9 mV output.