Daewoo DTX-21B4, Руководство по обслуживанию

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CP-520
V
Service Manual
41
n
Automatic decoder configuration and signal routing depending on the selected or detected
standard
n
FM overmodulation adaptation option to avoid clipping and distortion
5.3.1 Supported standards
The multistandard capability of the TV Sound Processor covers all terrestrial TV sound standards,
FM Radio and satellite FM.
The AM sound of L/L' standard is normally demodulated in the 1st sound IF. The resulting AF
signal has to been tered into the mono audio input of the TV Sound Processor. A second
possibility is to use the AMdemodulator in the DEMDEC part, however this may result in limited
performance.
Korea has a stereo sound system similar to Europe. It is supported by the TV Sound Processor.
Differences include deviation, modulation contents and identification. It is based on M standard.
Other features of the DEMDEC are:
n
M/BTSC and N standards supported
n
M/Japan (EIAJ) supported
n
FM Radio stereo decoding
n
Alignment-free, fully digital system
n
For BTSC full dbx® performance
n
SAP demodulation (without dbx®) simultaneously with stereo decoding, or mono plus SAP
with dbx®
n
Line/pilot frequency selectable from 15.734 kHz and 15.625 kHz (or automatic detection /
auto search)
n
High selectivity for pilot detection, high robustness against high-frequent audio components
n
Pilot lock indicator
n
SAP detector
n
Separate noise detectors for stereo and SAP with adjustable threshold levels, hysteresis, and
automute function
An overview of the supported standards and sound systems and their key parameters is given in
the following tables.
The analog multi-channel sound systems (A2, A2+ and A2*) are sometimes also named 2CS (2
carrier systems).
ANALOG 2-CARRIER SYSTEMS
[Table] Frequency modulation
MODULATION
STANDARD
SOUND
SYSTEM
CARRIER
FREQUENCY
(MHz)
FM DEVIATION(kHz)
NOM./MAX./OVER
SC1 SC2
BANDWIDTH/
DE-EMPHASIS
(kHz/us)
M Mono 4.5 15/25/50 Mono - 15/75
M A2+ 4.5/4.724 15/25/50 1/2(L+R) 1/2(L+R) 15/75(Korea)
B/G A2 5.5/5.742 27/50/80 1/2(L+R) R 15/50
I Mono 6.0 27/50/80 mono - 15/50
D/K(1) A2* 6.5/6.258 27/50/80 1/2(L+R) R 15/50
D/K(2) A2* 6.5/6.742 27/50/80 1/2(L+R) R 15/50
D/K(3) A2* 6.5/5.742 27/50/80 1/2(L+R) R 15/50
[Table] Identification for A2 systems