Sony WRT-807B, Service Manual

Page: 22 / 64

3-6
WRT-807B (U/CE)
3-2-5. Maximum Frequency Deviation
Adjustment
n
Be sure to perform this adjustment after “3-2-4. Reference
Frequency Deviation Adjustment” has been completed.
Equipment and Tools
DC power supply
DC output voltage : + 1.5
±
0.1 Vdc
DC ammeter
Audio analyzer
Modulation analyzer
Oscilloscope
SMA-BNC (J) connector (Part No. J-6402-490-A)
RF conversion connector (Part No. J-6402-400-A)
AF input cable (See “ How to make a AF input cable” on
page 3-1.)
Adjustor (Part No. 7-721-052-81)
Connections
Same as “3-2-4. Reference Frequency Division Adjustment”.
Switch and Control Setting
Same as “Switch and Control Initial Setting” on page 3-3.
Procedure
(1) Input 10 kHz,
_
18 dBV (
_
15.8 dBm) signal to the AF
input connector (CN303/CN-1868 board) with AF input
cable.
(2) Connect the modulation analyzer to the antenna connec-
tor (CN305) with SMA-BNC (J) connector (and RF
conversion connector).
Set the modulation analyzer as below;
MEASUREMENT
: FM
MEASUREMENT RANGE : AUTO or
±
100 kHz
(manual operation)
HPF : 50 Hz
LPF : 15 kHz or 20 kHz
DE EMPHASIS : 50
u
s
(3) Adjust 1 RV304 so that the frequency deviation for the
modulation analyzer reading meets the following speci-
fication.
Specification : Frequency deviation = Maximum
Adjustment : 1 RV304/MB-860 board (B side)
(4) Input 1 kHz,
_
18 dBV (
_
15.8 dBm) signal to the AF
input connector (CN303/CN-1868board) with AF input
cable.
(5) Adjust 1 RV303 so that the frequency deviation for the
modulation analyzer reading meets the following speci-
fication.
Specification : Frequency deviation
=
±
34.0 kHz
±
0.2 kHz
(for CE57/CE62/CE67 model)
= Maximum (for U30/U42/U62/U66 model)
Adjustment : 1 RV303/MB-860 board (B side)
(6) Adjust
1
RV304 so that the frequency deviation for the
modulation analyzer reading meets the following speci-
fication.
Specification : Frequency deviation
=
±
32.0 kHz
±
0.2 kHz
(for CE57/CE62/CE67 model)
=
±
33.0 kHz
±
0.2 kHz
(for U30/U42/U62/U66 model)
Adjustment :
1
RV304/MB-860 board (B side)