802BT/802R Video Test Generator User Guide 615
Description The left side starts with reference white (+100 IRE) and black (+7.5 IRE) levels. This is
followed by six bursts of sine waves. Each burst is at a different frequency, forming vertical
lines of various widths. The frequencies, going from left to right, are 0.5, 1, 2, 3, 3.58, and
4.43 MHz.
Test Frequency response
Method When viewed on a TV screen, the peak intensities of all of the bursts should match the
white reference level. The darkest portions between the peaks should match the black
reference level.
The image can also be used with a TV waveform analyzer to check the frequency
response of a video system. One scan line of the image, as it would appear on a waveform
analyzer, is shown at the top of the next page . High frequency roll-off (loss) would show
up as a decrease in the peak-to-peak swings on the right side of the waveform. Low
frequency roll-off would show up as a decrease in the peak-to-peak swings on the left side
of the waveform.
Some waveform analyzers can be set to detect and display the amplitude of the peaks. A
typical amplitude waveform for a good system is shown at the bottom of the next page.