Sony WRR-801A Service Manual page 23

2. Output level adjustment
Perform this adjustment when the TUNER OUTPUT
levels deviate from the specification.
Preparation
Before the adjustments, turn off the POWER switch of the
WRR-801A, and perform the followings.
1. Remove the case cover of the WRR-801A.
2. Remove the tuner unit form the WRR-801A.
3. Remove the upper side case lid of the tuner unit, and
insert the tuner unit to the slot of the WRR-801A.
Equipment and Tools
. Audio analyzer (level meter, distortion meter)
. Mic amp (Noise meter)
. Oscilloscope
. Adjuster (0.4 x 1.3 mm): (Part No. 7-221-652-81)
. DC cut fixture (See the "How to make DC cut fixture"
on page 3-1.)
Connection/Adjustment Location
Signal
TUNER
generator
OUTPUT 1
DC cut fixture
ANTENNA A IN
1 2 3
Tuner
WRU-801A
RV202 RV201
Tuner unit (WRU-801A)
WRR-801A
WRU-801A
Audio
MIC amp
analyzer
600 Z
balance
input
Oscilloscope
DC cut fixture
ANTENNA B IN
WRR-801A
4 5 6
Switch and Control Setting
Front panel (Tuner [1])
Channel setting: Group 00, 6901 channel
(800.125 MHz)
Muting: OFF
Rear panel
ATT (ANTENNA A, B) switch: 0 dB
Procedure
Step 1: Preparation
Set the signal generator as follows:
Signal generator setting
FREQUENCY (Carrier frequency): 800.125 MHz
RF OUTPUT (Output level): 60 dBuV
MODULATION (Modulation frequency): 1 kHz
DEVIATION (Frequency deviation): ± 5 kHz
Step 2: Tuner [1] (Tuner unit 1) adjustment
(1) Connect the audio analyzer to the TUNER OUTPUT 1
connector via MIC amp.
(2) Connect the signal generator to the ANTENNA A IN
connector with DC cut fixture.
(3) Adjustment (ANTENNA A IN side adjustment)
Specification: Output level (level meter indication
level) = _20 dBm ± 0.5 dB (at 600 Z
loaded)
Adjustment: 1RV202/RF board (Tuner unit 1)
(4) Connect the signal generator to the ANTENNA B IN
connector with DC cut fixture.
(5) Adjustment (ANTENNA B IN side adjustment)
Specification: Output level (level meter indication
level) = _20 dBm ± 0.5 dB (at 600 Z
loaded)
Adjustment: 1RV201/RF board (Tuner unit 1)
n
The output level difference between the ANTENNA
A side and the ANTENNA B side should be within
0.3 dB.
EMF
(= _53 dBm)
3-5