Pattern 8: "Phase" - Philips PM 5508 Operating Manual

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H. Pattern 8.
"PHASE"
Fig. VII-18. "PHASE"-pattern
This pattern is designed especially for checking the chroma demodulators.
The colour of the first bar is orange/yellowish, bar 2 is greenish, bar 3 is
rose and bar 4 is grey.
This pattern consists of the same four vertical bars as the previous one. The upper part of
the pattern is encoded according to the PAL alternating standard, while the lower part con-
tains colour information only on every "positive"-PAL-line. The latter means that only those
lines with a burst phase of 135° carry colour information. The burst is the normal PAL alter-
nating burst for the entire pattern, see vectordiagram, Fig. VII -19.
To ensure the same colour impression of the upper and lower parts of the pattern, the upper
part is generated with only half the chroma amplitude.
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Y
Y
Y
Y
1