Sansui 771 - 4-2. FM IF Alignment; 4-3. FM Dial Calibration and RF Alignment

4-2. FM IF Alignment (See Figs. 4-8 and 4-9 on page 10)
Note: 1, Selectofs ..s%desede ss uve vevaswes FM AUTO
2. Master Volume ........eeee eee Minimum
3. Output level of genescope ...... After attenuator
4. Sweepwidth.........sceeeeeeene 1.5~2cm/150kHz
5. Frequency band .......s+sesee 9.5~11.5MHz
GENE SCOPE
6. Connection
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Connect the output of
genescope to TP.A through 100p ceramic capacitor.
7. Before adjustment, turn both VRO1 and VRO2 CCW (Max.),
VRO3 CW (Max.) and VRO4 to center.
IN
4.7kQ 10pF
DETECTOR PROBE BLOCK
FEED SIGNAL MEASURE
STEP SUB ADJUST ADJUST FOR CONDITION
| ESE | FROM | TO OUTPUT
1 IF coil Output 55dB Base of TRO1| Connected TO1,T02 | Max. IF wave- | oTurn core of T06
Genescope on F-1479 Point between form 1 as CC
(Fig. 4-9 R48 & R50 on Fig. 4-8
TP.A) F-1479
(Fig. 4-9 TP.B)
Use Detector
Probe ~°
2 Meter coil Same as above Same as Connected T06, TO7 Max. IF wave-
above point between from 2
R62 & VRO2 on Set the center
F-1479 of wavefrom 2
(Fig. 4-9 TP.D) with wavefrom
Direct from 1 as Fig. 4-8
Genescope
3 Descrimina- | Same as above Same as Connected T04 Max. linearity
tor coil above point between of S curve
R67 & R68 on TO5 Set the center
F-1479 of S curve
(Fig. 4-9 TP.C) wavefrom 1 &
Direct from 2 as Fig. 4-8
Genescope
4 IF coil Same as above Same as above } 103 Max. noise
4-3. FM Dial Calibration and RF Alignment (See Fig. 4-9 on page 10)
Note: Selector FM AUTO
. Master Volume Minimum
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. Confirm start point of dial pointer before alignment.
1.
2
3. FM Muting switch OFF (pushed in)
4
5. In Step 3, 4 and 5, 1 and 2 are readjusted, repeat 3, 4 and 5 again.
FM SSG
FEED SIGNAL MEASURE
STEP UBJECT ADJUST ADJUST FOR CONDITION
| aun | FROM | TO | OUTPUT )
1 | 88MHz 88MHz ANT REC OUTLor | L04 Max. output oSet Dial on 88MHz
Dial Calibration | ANT input 60dB terminal | R-ch
1kHz (100% MOD) | 3009 VTVM & Scope FM
FM
SSG
i
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2 | 108MHz 108MHz Same as | Same as Trimmer Same as eSet Dial on 108MHz
Dial Calibration | ANT input 60dB above above TC04 above
1kHz (100% MOD)
FM SSG is
104 = 106
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