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CP-850/F Service Manual
4.4.1.2 DSP-Section (Audio Baseband Processing)
flexible selection of audio sources to be processed
performance of terrestrial de-emphasise systems (FM, NICAM)
digitally performed FM-identification decoding and de-matrixing
digital baseband processing: volume, bass, treble
simple controlling of volume, bass, treble
4.4.1.3 Analogue Section
two selectable analogue pairs of audio baseband input (= two SCART inputs) input level: <2 V RMS, input
impedance: >25
one selectable analogue mono input (i.e. AM sound): Not used in this chassis
two high-quality A/D converters, S/N-Ratio: >85 dB
20 Hz to 20 kHz bandwidth for SCART-to-SCART copy facilities
loudspeaker: one pair of four-fold oversampled D/A converters. Output level per channel: max.
1.4 VRMS output resistance: max. 5 k . S/N-ratio: >85 dB at maximum volume max. noise voltage in mute mode:
< 10
(BW: 20 Hz... 16 kHz)
one pair of four-fold oversampled D/A converters supplying a pair of SCART-outputs. Output level per channel:
max. 2 V RMS, output resistance: max. 0.5 k , S/N-Ratio: >85 dB (20 Hz... 16 kHz)
4.4.1.4 NICAM & FM/AM-Mono
According to the British, Scandinavian, Spanish, and French TV-standards, high-quality stereo sound is transmitted
digitally. The systems allow two high-quality digital sound channels to be added to the already existing FM/AM-channel.
The sound coding follows the format of the socalled Near Instantaneous Companding System (NICAM 728).
Transmission is performed using Differential Quadrature Phase Shift Keying (DQPSK. Table below offers an overview of
the modulation parameters.
In the case of NICAM/FM (AM) mode, there are three different audio channels available: NICAM A, NICAM B, and
FM/AM-mono. NICAM A and B may belong either to a stereo or to a dual language transmission. Information about
operation mode and about the quality of the NICAM signal can be read by the controlling software via the control bus. In
the case of low quality (high bit error rate), the controlling software may decide to switch to the analogue FM/AM-mono
sound.
Alternatively, an automatic NICAM-FM/AM switching may be applied.
4.4.1.5 German 2-Carrier System (DUAL FM System)
Since September 1981, stereo and dual sound programs have been transmitted in Germany using the 2-carrier system.
Sound transmission consists of the already existing first sound carrier and a second sound carrier additionally
containing an identification signal. More details of this standard are given in Tables below. For D/K very similar system
is used.
TV standards
TV system
Position of sound carrier (MHz)
B/G
5.5 / 5.7421875
B/G
5.5 / 5.85
L
6.5 / 5.85
I
6.0 / 6.552
D/K
6.5 / 6.2578125 D/K1
6.5 / 6.7421875 D/K2
6.5 / 5.85 D/K-NICAM
B
5.5
Sound modulation
FM Stereo
FM-Mono / NICAM
AM - Mono / NICAM
FM-Mono / NICAM
FM Stereo
FM-Mono / NICAM
FM Stereo
-32-
Colour system
Country
PAL
GERMANY
PAL
Scandinavia,
Spain
SECAM-L
France
PAL
UK
SECAM-
USSR
East
Hungary
PAL
AUSTRALIA
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