Loewe Q2500B Serviceanleitung Seite 180

Technology of Q 2500 colour TV set
Parameter
Chip
ADC
ADC-Type
Resolution
Sampling Clock
IQ input voltage
Demodulation
Procedure
Symbol rate range STV0299B
Symbol rate over all (including
tuner) without neighbouring
channel assignment
Symbol rate over all with
neighbouring channel assign-
ment
Preferred value for symbol rate
Other symbol rates
Roll off filtering
Roll off factor
Used roll off factor
Carrier recovery
Pulse recovery
Processing of the normal or
inverting spectrum
Document Q 2500
Value/algorithm
STV0299B
Dual
2*6 bit
Variable, dependent on symbol
rate
1 Vss
Coherent grey coded QPSK
demodulation
1...45 Mbaud
1...30 Mbaud
15...30 Mbaud
27.5 and 22 Mbaud
Decoding from NIT (delivery
system descriptor) of Barker
Channel or manual selection
Half Nyquist
0.20 (20 %); 0.35 (0.35 %)
0.35 (35 %)
Digital PLL with internal de-
rotator and hardware lock-in
detector
Internal digital PLL
57
Notes
Manufacturer: ST Microelec-
tronics
Generated by on chip PLL
Lower limit: Phase noise of
tuner
Upper limit: IF bandwidth of
tuner
Used in frequency search pro-
cedure
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