Sony STR-W777, Service Manual

Page: 11 / 64

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FM Polar Adjustment (East European, CIS model)
Connection 1 :
Connection 2 :
Procedure :
1.
Set the modulation of FM RF SSG to AUDIO 1 kHz, 10 kHz
deviation according to “Connection 1”.
2. Tune the set to 69 MHz.
3. Adjust the RV1702 so that the reading of frequency counter
connected to TP1702 (VCO) becomes within 31.25 kHz ± 0.05
kHz. (VCO adjustment)
4. Then record the reading of the level meter connected to TP1701.
5. Set the modulation of FM RF SSG to AUDIO 31.25 kHz, 10
kHz deviation according to “Connection 2”.
6. Tune the set to 69 MHz.
7. Set the CT1701 to be mechanical center.
8. Adjust the L1701 so that the reading of the level meter
connected to TP1701 (FILTER) becomes maximum.
Then adjust the CT1701 so that the reading of the level meter
connected to TP1701 (FILTER) becomes maximum. (SUB
CARRIER PEAK Adjustment)
9. Adjust the RV1701 so that the level at the moment becomes 14
dB higher value than the level recorded in step 4. (SUB
CARRIER LEVEL Adjustment)
Adjustment Location: TCB board
Adjustment Location:
[TCB BOARD] (Conductor Side)
FM antenna
terminal (75
Ω
)
FM RF SSG
75
Ω
coaxial
Carrier frequency: 69 MHz
Output level:
1 mV (60 dB
µ
) (at 75
Ω
open)
Modulation: AUDIO 1 kHz, 10 kHz deviation
set
FM antenna
terminal (75
Ω
)
Audio 31.25 kHz
external
modulation
terminal
FM RF SSG
AF OSC
75
Ω
coaxial
Carrier frequency: 69 MHz
Output level:
1 mV (60 dB
µ
) (at 75
Ω
open)
Modulation: AUDIO 31.25 kHz, 10 kHz deviation
(EXTERNAL MODULATION)
set
frequency counter
level meter
TP1701
(FILTER)
TP1702
(VCO)
IC1701
L1701
CT1701
Sub Carrier Peak
RV1701
Sub Carrier
Level
IC1701
RV1702
VCO
[TCB BOARD] (Component Side)