Sherwood R-772 Service Manual page 21

3-2. AM Alignment
• Output of signal generator should not be greater than necessary to obtain an optimum output reading.
• Signal generator modulation : 30%
• Signal frequency : 400Hz
• Modulation frequency : 600, 1000, 1400kHz
• Switch : press the BAND Button to AM
Signal generator
Step
Subject
1 Tuning voltage
2 RF Tracking
3 IF Tracking
4 Seek level
3-3. FM Alignment
• Output of signal generator should not be greater than necessary to obtain an optimum output reading.
• Signal generator modulation : MAIN : 53.3%, PILOT : 10%
• Signal frequency : 1kHz / Deviation : 40kHz
• Modulation frequency : 90.0MHz, 98.0MHz, 106.0MHz
• Switch : press the BAND Button to FM
Signal generator
Step
Subject
1
Tuning voltage 87.5MHz
2
FM DET.0V 98.0MHz
and
Distortion Adj
3 Seek stop level 98.0MHz
4 STEREO 98.0MHz
Separation
Set frequency
setting setting
522kHz 522kHz
603kHz 603kHz
603kHz 603kHz
603kHz 603kHz
Set frequency
setting setting
87.5MHz
108MHz 108MHz
98.0MHz
98.0MHz
98.0MHz
Equipment
Adjustment point
connection
DC voltmeter RF BLOCK
OSC coil
AC voltmeter RF BLOCK
oscilloscope ANT coil
tape monitor L/R
AC voltmeter IF BLOCK
oscilloscope Coil KSNT-104I
tape monitor L/R
AC voltmeter SVR 03
oscilloscope
tape monitor L/R
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
20
Adjust for
522kHz : 1.1~1.3V
1611kHz: 7.2V~8.5V
(DC 1.2± 0.1V)
Maximize audio output
Repeat LOW, HIGH
frequency
Maximize audio output
Tuned on point
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