Tektronix WFM700 Series, Service Manual

Page: 51 / 194

Performance Verification
WFM700 Series Waveform Monitors Service Manual
2- 19
This step checks the active video and of black (blanking) levels.
Performance Requirement.
This test verifies performance characteristics and is
listed in the test record.
1. Connect the HD video generator to INPUT A using a 75
8
cable.
2. Press the INPUT button and select Input A .
3. Set the HD video generator for a 1080i 59.94 100% color bars signal.
4. Connect the PIX G/Y output to the 75
8
input of the test oscilloscope using
a 75
8
cable. Use a 75
8
-to-50
8
adapter on the input of the test oscillo-
scope if necessary.
5.
Press the
CONFIG
button.
6.
Touch the
Video Inputs/Outputs
soft key, then
Next Menu
.
7. Touch the Output Active for HD soft key, then YPbPr .
8. Press the CONFIG button twice to exit menu.
9. Set the test oscilloscope to view the first color bar. The following oscillo-
scope settings normally provide a usable display.
Vertical Scale 100 mV/div
Vertical Position –3.5 div
Horizontal Scale 1 us/div
Horizontal Trigger Position 50%
Trigger Slope Rising edge
Trigger Level 500 mV
10. Measure the amplitude between the black level and the first color bar and
note the measurement. See Figure 2--5.
11.
Calculate the percent amplitude error using the formula:
Amplitude Error
Æ
Measured Amplitude mV 700 mV
É
7
12. CHECK that the calculated error is between 5%.
13. Measure the amplitude of the black level (the level preceding the first color
bar step) referenced to ground on the test oscilloscope. Note the measure-
ment. See Figure 2--5.
14.
CHECK that the black level is between 25 mV.
PIX Video Output Level