Bpf F0 Adjustment (Vc-197 Board) - Sony GV-A500 Service Manual

3. BPF f0 Adjustment (VC-197 board)

Sets the BPF passing frequency so that the AFM signal can separate
from the playback RF signal properly. If deviated the mono/stereo
mode will be differentiated incorrectly, and noises and distortions
will increase during high volume playback.
Mode Playback
Signal Alignment tape:
For BPF adjustment
(WR5-11NS (NTSC))
(WR5-11CS (PAL))
Measuring point Right or left audio output terminal
Measuring device Distortion meter
Adjustment page F
Adjustment address 54
Specified value The Main and Sub channel distortion
rates should be almost the same
(within ± 1%) and minimum
Note : NTSC model : GV-A500
PAL model : GV-A500E
Adjustment method:
1) Set page: 0, address: 01, data: 01.
2) Set the Hi-Fi sound switch (menu display) to " 2 ".
3) Change the data of page: F, address: 54 and minimize the
distortion rate.
4) Press the PAUSE button of the adjusting remote commander.
5) Set the Hi-Fi sound switch to " 1 ".
6) Change the data of page: F, address: 54 and minimize the
distortion rate.
7) Press the PAUSE button of the adjusting remote commander.
8) Repeat steps 2) to 7) and set the data of address: 54 so that the
distortions rates when the Hi-Fi sound switch is set to " 2 "
and set to " 1 " respectively are almost the same and minimum.
9) Press the PAUSE button of the adjusting remote commander.
10) Set page: 0, address: 01, data: 00.
11) Set the Hi-Fi sound switch to "STEREO".
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