Battery Alarm Signal Check - Sony WRT-807B Service Manual

2. Frequency check
Connections
(For connecting the DC power supply, refer to the "Prepara-
tion" on page 3-2.)
Modulation
SMA-BNC (J) connector with
analyzer
RF conversion connector
RF IN
CN305
Procedure
n
Perform the checking with the AF input connector (CN303/
CN-1868 board) short-circuit.
(1) Connect the modulation analyzer to the antenna connec-
tor (CN305) with SMA-BNC (J) connector (and RF
conversion connector), and connect the frequency
counter to the AF OUT connector on the modulation
analyzer.
(2) Set the modulation analyzer as below;
MEASUREMENT
MEASUREMENT RANGE : ± 10 kHz
HPF
LPF
DE EMPHASIS
(3) Check that the frequency counter (resolution : 0.1 Hz
setting) reading is 32.768 kHz ± 1Hz.
3-10
Frequency
counter
AF OUT
MB-860 board (B side)
: FM
: 4 kHz
: >20 kHz
: OFF

3-2-10. Battery Alarm Signal Check

Equipment and Tools
DC power supply
DC output voltage : +1.5 ± 0.1 Vdc
DC ammeter
Frequency counter
Spectrum analyzer
Modulation analyzer
SMA-BNC (J) connector (Part No. J-6402-490-A)
RF conversion connector (Part No. J-6402-400-A)
Switch and Control Setting
Same as "Switch and Control Initial Setting" on page 3-3.
1. Frequency deviation check
Connections
(For connecting the DC power supply, refer to the "Prepara-
tion" on page 3-2.)
GND
Connect a jumper wire between TONE land
and GND land by soldering.
(TONE signal : OFF)
CN305
SMA-BNC (J)
connector with
RF conversion connector
Jumper wire
TONE
MB-860 board (B side)
Spectrum
analyzer
WRT-807B (U/CE)