Filter
Top Products
Performance Verification
5–14
VITS100 NTSC VITS Inserter Instruction Manual
Noise
generator
VITS Inserter
Television test signal generator
Video measurement set
Test Signal
75ĂW
Terminator
Program Out
Program In
Figure 5–8: Measuring hum rejection
6. Select Waveform on the video measurement set.
7. Check that hum is present on the porch before and after sync.
8. Check that the porch before burst drifts up and down at hum rate.
9. Check that the back porch following burst drifts less than 0.32 IRE at the
hum rate.
10. Turn video noise generator Hum off.
Requirement: Luminance risetime + 140 ns "20 ns
1. Connect a 75 W coaxial cable from the television test signal generator Test
Signal output to the VITS inserter PROGRAM IN. See Figure 5–2.
2. Connect a 75 W coaxial cable from the VITS inserter PROGRAM OUT to
the waveform/vector monitor Ch A Input. Terminate the remaining side of
the loop-through input with a 75 W terminator. See Figure 5–2 on page 5–6.
3. Measure the leading edge of the bar between the 10 and 90% points (10 IRE
to 90 IRE on the waveform graticule).
4. Check that the risetime is between 120 ns and 160 ns.
Luminance Risetime