![background image](http://html.mh-extra.com/html/sony/hcd-d90av/hcd-d90av_service-manual_420613017.webp)
— 17 —
FM Polar Adjustment (East European, CIS model only)
Connection 1 :
FM RF SSG
FM antenna
terminal (75
Ω
)
75
Ω
coaxial
set
Carrier frequency: 69 MHz
Output level:
1 mV (60 dBµ) (at 75
Ω
open)
Modulation:
AUDIO 1 kHz, 10 kHz deviation
Connection 2 :
75
Ω
coaxial
FM RF SSG
FM antenna
terminal (75
Ω
)
AF OSC
Audio 31.25kHz
external
modulation
terminal
Carrier frequency: 69 MHz
Output level:
1 mV (60 dBµ) (at 75
Ω
open)
Modulation:
AUDIO 31.25 kHz, 10 kHz deviation
(EXTERNAL MODULATION)
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 con-
nected 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 con-
nected to TP1701 (FILTER) becomes maximum.
Then adjust the CT1701 so that the reading of the level meter
connected to TP1701 (FILTER) becomes maximum. (SUB CAR-
RIER 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 CAR-
RIER LEVEL Adjustment)
[TCB BOARD] (Component Side)
RV1701
Sub Carrier
Level
L1701
IC1701
RV1702
VCO
Sub Carrier Peak
CT1701
set
+
_
frequency counter
level meter
TP1701
(FILTER)
TP1702
(VCO)
IC1701
Adjustment Location: TCB board
Adjustment Location
[TCB BOARD] (Conductor Side)