Sony CRF-230B - Adjustment

3-5. MUTING LEVEL SETTING
Preparation:
Band Selector: FM1
MUTING Switch: ON
ROD ANT-EXT ANT Switch: EXT ANT
Rf signal Generator Connection:
To FM EXT ANT terminal (752)
VTVM Connection:
To EXT SP jack in parallel with 42
resistor
Modulation:
Fm 400-Hz + 22.5-kHz frequency-modu-
lated signal (rf signal: 77.5 MHz)
Note: Be sure that fm i-f section is operating
in normal condition before setting the
muting level.
rf signal
generator
test set
CRF-230B8
Oo :
FM EXT ANT
4Q resistor
Fig. 3-8 Muting level setting setup
Procedure:
1. Detune from rf signal.
2. Turn the muting level adjustable resistor
VR901 fully counterclockwise.
3. Gradually turn VR901 clockwise and set it
at the position that the VTVM shows mini-
mum indication.
rf signal
generator
adjustable resistor
= muting level
(VR901)
Fig. 3-9 RF signal generator connection and
parts location
Rf Signal Receiver
Generator Dial
Frequency Setting
90 MHz (Detune
from rf signal of
77.5 MHz)
Muting level
adjustable
resistor VR901
77.5 MHz
3-6. FM1/FM2 FREQUENCY COVERAGE ADJUSTMENT
Preparation:
ROD ANT-EXT ANT Switch: EXT ANT
Rf Signal Generator Coupling:
‘Direct connection across FM EXT
ANT terminal (752)
Rf Signal Modulation:
400-Hz + 22.5-kHz frequency- modulated
signal
VTVM Connection:
To EXT SP jack in parallel with 42
resistor
Rf Signal Receiver
Adjusting
Generator
Tuning
Knob
Item
rf signal
generator
test set
CRF-230B
(e) cc“
FM EXT ANT 492 resistor
Fig. 3-10 FM1/FM2 frequency coverage and
tracking adjustment setup
Adjust Remarks
Frequency Setting
‘ Fully
FM 1 75 MHz counter-
Frequency
clockwise
FM 1 ose coil Band Selector: FM 1
pags Adjust for maximum
Coverage
- 91.5 MHz Pally
clockwise
Fully
FM
2
86.5
MHz
counter-
Frequency clockwise
FM 1 osc trimmer meter reading on
CT014 VTVM.
FM 2 osc coil
L104
Band Selector: FM 2
Adjust for maximum
Coverage Fully
109.5
MHz
clockwise
FM 2 osc trimmer meter reading on
CT1014 VTVM.