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ALlGNMENT PROCEDURES
PLL2 VCO Alignment
Control Settin"
Test Instrument Connection
Adjust
Result
OFFNOLUME control: ON.
Connect DC SSYM to TP4.
LS4
Adjust LS4 lor 3±0.2 volts on
SQUELCH control: Fully coun-
See Figure 1 on Page 14.
the DC SSVM.
terclockwise (CCW).
See "How to Adjust Coils L47,
Select channel 1.
LSO, and LS4."
PLL1 VCO Alignment
Control Setting
Test Instrument Connection
Adjust
Result
OFFNOLUME control: ON.
Connect DC SSVM to TP3.
L47
1. Select channel 2 and adjust
SQUELCH control: CCW.
See Figure 2 on Page 14.
LSO
L47 lor 20 volts on the DC
Select channels 2, 3, and 4.
SSVM. See Table 2.
2. Select channel 3 and be sure
the DC SSVM reads 9-13
volts
(no adjustments
are
necessary lor the coll).
3. Select channel 4 and adjust
LSO lor 22 volts on the DC
SSVM.
4. Repeat above 1 to 3 until no
lurther improvement is ob-
served. See Table 2.
Haw
to
Adjust Cails L47, L50, and L54
Each of the coils should be adjusted by changing the pitch ol the coil little by little by carelully using a non-metallic
tuning tooi as shown in Figure 3.
Increase the pitch ol the coil when the measured voltage at TP3 or TP4 is higher than the voltage specilied in the re-
sult column lor "PLL2 VCO Alignment" and "PLL1 VCO Alignment."
Decrease the pitch ol the coil when the measured voltage at TP3 or TP4 is lower than the voltage specilied in the re-
sult column lor "PLL2 VCO Alignment" and "PLL1 VCO Alignment."
/1--
~~~-metallic
Coil
11'
tuningtooi
\111"'I~lll/!liliIIl"'4
Main PCB
Figure 3
Notes:
Be very carelul when doing coil pitch adjustment because
it gratly affects the Irequency.
Secure the coil with glue after alignment. Be sure the glue
is dry and the coil is secured. Also, be sure that the envi-
ronmental temperature is normal. Then, repeat VCO
(PLL2 and PLL1) alignments above.
- 1 3 -
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