Sony WRR-855B, Service Manual, Page: 30 / 84

3-14
WRR-855B
3-2-2. Overall Characteristic Confirmation
Check the overall characteristics by following the proce-
dure below.
When checking the system, the system must be repackaged
in the normal operating condition (the case and front panel
are attached) and the check must be performed by follow-
ing procedure below.
n
When checking the overall characteristics after completing
''3-2-1. TUN-8 Board Adjustment" , perform the ''Step2
Works after completing adjustment" on page 3-13.
Procedure
1. Current Consumption Check
↓
2. S/N Check
↓
3. Frequency Characteristic Check
↓
4. Distortion Ratio Check
↓
5. RF Level Indicator Check
↓
6. AF Level Indicator Check
Equipment and Tools
• DC power supply: + 7.0
±
0.1 Vdc
• Signal generator
• Audio analyzer
• MIC amp (Noise meter) with A-weighted filter
• Oscilloscope
• DC ammeter
• Power supply/AF OUT connector
(Refer to the ''How to make power supply/AF OUT
connector" on page 3-1.)
Switch and Control Setting
Channel setting:
CE21 model; Group 00, 22-32 channel (482.000 MHz)
CE33 model; Group 00, 34-32 channel (578.000 MHz)
CE62 model; Group 00, 63-32 channel (810.000 MHz)
CE67 model; Group 00, 68-32 channel (850.000 MHz)
U14 model; Group 00, 16-01 channel (482.125 MHz)
U30 model; Group 00, 32-01 channel (578.125 MHz)
U42 model; Group 00, 44-01 channel (650.125 MHz)
U62 model; Group 00, 64-01 channel (770.125 MHz)
U66 model; Group 00, 68-01 channel (794.125 MHz)
MUTING: OFF
(2) Turn on and off the MODULATION (modulation
frequency) of the signal generator as follows, and
check that the voltage at the IC201-13 pin (TONE) of
the CPU-342 board changes also as follows:
MODULATION of IC201-13 pin/
signal genarator CPU-342 board voltage
ON 0 V
OFF About 4.8 V
(3) Connect the signal generator to the ANT IN B connec-
tor, and perform the procedures (1) and (2) above.
Step2:
Works after completing adjustment
After completing adjustment (''3-2-1. TUN-8 Board
Adjustment"), turn off the main power of the WRR-855B
and perform the following work then proceed to ''3-2-2.
Overall Characteristics Check'' .
1
Attach the T case lid (A) of the unit assembly.
2
Attach the front panel and case.
IC201
13pin
DC voltmeter
+
_
CPU-342 board
Case