Fluke 54200, User Manual

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54200
Users Manual
4-48
White Pattern
Figure 4-74. White Pattern
Description:
White is a fullfield pattern with color burst.
In 625 line systems the white level is selectable:
Y = 0%, 5%, 15% to 100% in 5% steps.
In 525 line systems:
Y = 7.5 IRE, 15 IRE to 100 IRE in 5 IRE steps.
Applications:
White pattern is designed for a proper white setting
and for an overall check of purity. It is also useful for
adjustment of the maximum beam current of the
picture tube. In addition, the brightness control
circuitry test can be carried out.
For videocassette recorders the luminance play back
level, the AGC level, and the E-E level (feedthrough
signal electronic to electronic) are checked or adjusted
by means of the 100% white signal. Furthermore the
'white/dark clip' and the 'white frequency' of the
FM modulator are adjusted by this pattern.
For SVHS recorders the white pattern is additionally
used as CVBS or Y/C signal to adjust phase
corrections (Y and chroma skew levels) or the red and
green levels of the RGB decoder.
Multiburst
Figure 4-75. Multiburst
Description:
Multiburst contains a reference bar followed by six
full screen vertical frequency bursts according CCIR
Rec. 473-5. These frequencies are 0.5, 1.0, 2.0, 4.0,
4.8, and 5.8 MHz for 625 line systems. Because of a
lower bandwidth for the 525 line systems the upper
three frequencies are 3.0, 3.58, and 4.2 MHz.
Applications:
This pattern checks the bandwidth of the video or
luminance amplifier in B/W or CTVs as well as the
resolution of monitors and video recorders. It can also
be used to check or measure the frequency amplitude
response. Furthermore, the luminance suppression of
the Y/C separator of a SVHS recorder is adjusted by
this pattern.