JVC MF-47L - Page 12

MF-47L/ML
FM IF and discriminator alignment
Equipment required : 10.7MHz Sweep Generator with Oscilloscope
Input terminal : Cin Fig. 18
Output terminal : Bin Fig. 18
Adjust T103 as shown in Fig. 16
FM RF alignment
Equipment required : Standard Signal Generator (Modulation 1000Hz,
100% (75kHz/Div.)
Output impedance 300 ohms, AC voltmeter,
oscilloscope.
Input terminal : FM Antenna Terminal
Output terminal : Speaker terminal (4Q load)
Fig. 16
Set V. Capacitor to
(Dial Needle)
Set to “MANUAL” & “AFC OFF’. Regarding VR104,201,202,203, set to their center positions.
87.3MHz VR104 Maximum (Left end)
109MHz VR202 Minimum( Right end)
Repeat the Step 2 & 3.
9OMHz V R203 90MHz *
106MHz VR201 106MHz *
Repeat the Step 5 & 6, and adjust for no further improvement.
aa =
* Adjust frequency meter to 9OMHz and 106MHz respectively.
PLL MPX VFO alignment Separation alignment
Connect a frequency counter to TP and adjust the VR102 Adjust the VR101 so that left and right channel separation
until! 19kHz is obtained. will be maximum.
Note: If any input is present at the ANT terminal, the
input frequency is pulled in. Be sure to detune
before alignment.
| | ant coifie
cer )"G
i Lo
ANT Trimmer
RF Coil
RS
TIP
i
|
Fig. 17 Fig. 18
—~12-—