Sony CA-755 Maintenance Manual page 36

2-4. TR-101 Board Adjustment
2-4-1. Carrier Frequency Adjustment
2-4-2. PGM/INCOM Demodulation Circuit Adjustment
2-4. TR-101 Board Adjustment
Preparations :
1. Disconnect the cable from the DC IN connector on the
CA-755/755P .
2. Connect the CA-755/755P to the CCU using a triaxial
cable. Turn on the POWER switch of the CCU.
2-4-1. Carrier Frequency Adjustment
Preparation :
. Perform this adjustment a minute or more after turning
on the power.
To be extended : TR-101 board
Equipment : Frequency counter
Test point Adjustment point
TP3 1LV2
TP2 1LV1
1LV3
TP4
2-10 (E)
2-4-2. PGM/INCOM Demodulation Circuit
Note :
Carefully adjust an adjusting core such as LV8.
To be extended
Equipment
Test points
Adjustment points : 1LV8 (INCOM DC)/TR-101 board
Adjustment procedure
1. When rotating 1LV8/TR-101 board clockwise or
Specifications
5.600 ± 0.003 MHz
6.200 ± 0.003 MHz
7.100 ± 0.003 MHz
2. Adjust 1LV8/TR-101 board so that the DC level at
3. Adjust 1LV7/TR-101 board so that the DC level at
Adjustment
: TR-101 board
: Oscilloscope
: TP12, TP11/TR-101 board
1LV7 (PGM DC)/TR-101 board
counterclockwise, the DC level at TP12/TR-101 board
will be changed as follows.
DC level
TP12/TR-101 board is set to the center of maximum
and minimum values.
TP11/TR-101 board is set to the center of maximum
and minimum values.
Oscilloscope screen
MAX
CENTER
MIN
Rotation of the core
MAX
CENTER
MIN
CA-755/755P