Sherwood R-772 Service Manual page 20

2-3. FM Alignment
• Output of signal generator should not be greater than necessary to obtain an optimum output reading.
• Signal generator modulation : MAIN : 90%, PILOT : 10%
• Signal frequency : 1kHz / Deviation : 75kHz
• Modulation frequency : 90.1MHz, 98.1MHz, 106.1MHz
• Switch : press the BAND Button to FM
Signal generator
Step
Subject
1
Tuning voltage 87.5MHz
2 FM DET.0V 98.1MHz
and
Distortion Adj
3 Seek stop level 98.1MHz
4
STEREO 98.1MHz
Separation
3. RDS Version Alignment
3-1. Alignment and Test Point
Set frequency
setting setting
87.5MHz
108MHz 108MHz
98.1MHz
98.1MHz
98.1MHz
FM STEREO SEPARATION Adj.
SVR01
FM AUTO STOP LEVEL Adj.
Equipment
Adjustment point
connection
DC voltmeter
AC voltmeter FD1 , FD2
oscilloscope R17
DC voltmeter
tape monitor L/R
AC voltmeter SVR 01
oscilloscope
tape monitor L/R
AC voltmeter MIX coil CO4
oscilloscope
DC voltmeter SVR02
tape monitor L/R
SVR02
19
Adjust for
87.5MHz : 1.35~1.65V
108MHz : 6.5V~8.5V
(DC 1.2± 0.1V)
Minimize 0V and distortion
Scan stop point to 18dBu
Minimize STEREO distortion
and Maximize separation
Separation L to R
Separation R to L