Spurious Emissions Check - Sony WRT-800A Service Manual

2. Frequency check
Connections
(For connecting the DC supply, refer to the "Preparations"
on page 3-3.)
RF-87 Board
RF adjusting connector
SMA-BNC
conversion connector
Frequency counter
Modulation analyzer
RF IN AF OUT
Switch and control setting
S301, S302, S303, S304/ RF-87 board (A-side)
WRT-800A S301
AU66 model _
Procedure
(1) Set the modulation analyzer as below:
MEASUREMENT
MEASUREMENT RANGE : 40 kHz
HPF
LPF
DE EMPHASIS
(2) Set the DC output voltage of DC power supply to 1V
± 0.1 V so that battery alarm signal goes on.
(3) Check that the frequency counter (resolution : 0.1 Hz)
reading is 32.782 kHz± 1 Hz.
(4) After the checking, remove (unsolder) the jumper wire
between TONE and GND on the AU-258 board.
3-11
AU-258 Board
(B side) (A side)
TONE
Connect a jumper wire
between TONE land and
GND land by soldering.
(TONE signal OFF)
S302 S303 S304 Channel
setting
0 1 OFF 67-01
: FM
: 4 kHz
: >20 kHz
: OFF

3-2-11. Spurious Emissions Check

Equipment and Tools
DC power supply
DC output voltage:+1.5± 0.1 Vdc
DC current meter
Spectrum analyzer
RF adjusting connector (See page 3-2.)
Switch and control setting
S301, S302, S303, S304/ RF-87 board (A-side)
WRT-800A S301
AU66 model _
Connections
(For connecting the DC power supply, refer to the "Prepa-
rations" on page 3-3.)
RF adjusting connector
SMA-BNC
conversion analyzer
Spectrum analyzer
S302 S303 S304 Channel
setting
0 1 OFF 67-01
RF-87 Board AU-258 Board
(B side) (A side)
WRT-800A (AU)