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Chapter 7: DEC-6804 Decoder and DES-6804 Decoder with Frame Synchronizer
Features
80
6800/7000 Series - Audio and Video Multi/Demultiplexing Products Installation and Operation Manual
Features
The following list highlights the features of the DEC-6804 and the
DRS-6804:
• Analog video processing at
±
6 dB gain range
•
±
7.5
IRE black level
• 360
°
hue adjustment allowing full-range user control
• Over-sampling analog-to-digital conversion with 12-bit resolution
• TBC capabilities, locking to VHS or bad microwave feeds
(DES-6804 only)
• 2-D adaptive comb filtering utilizing the new Leitch PQM™
technology
• Automatic PAL/NTSC switching (based on input signal)
• Full VBI handling and processing (line by line)
• Test signal generation (75% color bar, FCC composite, black)
• Full compatibility with existing frames
The new Phase Quadrature Mixing (PQM™) technology provides the
highest degree of video decoding quality while minimizing the level of
residual subcarrier artifacts associated with previous comb filter
designs.
The PQM™ decoding technology is based on a set of dynamic control
signals that are derived from specific quadrature characteristics of the
source video signal. These signals are filtered and subsequently used to
modulate the summation of the original source video components, in a
balanced mixer hierarchy that mirrors the control signal quadrature
relationship.