cxa1518s Sony Electronics, cxa1518s Datasheet - Page 15

• Manufacturer Part Number: cxa1518s
• Description: Eiaj Sound Multiplexing Decoder
• Manufacturer: Sony Electronics

2
3
4
Adjustment Methods
1. Preset before filter adjustment
Procedure
Main system
MAIN DEEM applies de-emphasis on the MAIN signal component and removes the SUB and Cue
components. After having passed through MAIN DEEM, the MAIN signal is added to MARTIX, OUTPUT
AMP, and MAIN OUT.
Sub system
SUB BPF passes the SUB signal component of the multiplexed signal. A 4.5f
digital facsimile signal component.
FM demodulation frequency demodulates the Sub signal.
The SUB DEEM applies de-emphasis on the FM demodulated Sub signal and removes the carrier wave
component.
After passing through SUB DEEM, the SUB signal is added to MATRIX and OUTPUT AMP.
Matrix and output system
When broadcasting in stereo, MATRIX generates L and R signals by adding and subtracting the MAIN
signal from MAIN DEEM and the SUB signal from SUB DEEM.
OUTPUT AMP & OUTPUT SW switch the output signals as instructed by LOCIG. Note that MAIN OUT
always outputs the MAIN signal component regardless of the broadcast mode.
1) Connect as shown in Fig. 1
2) Set the encoder to MONO MODE, and input a 1 kHz signal to MPX IN.
3) Adjust VR2 until the level on TP1 (Pin 6) is 0.2 Vp-p (70 mVrms).
Japan sound multiplexing encoder
(Pin 3 for the CXA1518Q)
—15—
Fig. 1
MPX IN
TP1
VR2
Application circuit
Oscilloscope
H
trap filter then removes the
CXA1518Q/S