Sony WRT-807B, Service Manual

Page: 26 / 64

3-10
WRT-807B (U/CE)
2. Frequency check
Connections
(For connecting the DC power supply, refer to the “Prepara-
tion” on page 3-2.)
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 : FM
MEASUREMENT RANGE :
±
10 kHz
HPF : 4 kHz
LPF : >20 kHz
DE EMPHASIS : OFF
(3) Check that the frequency counter (resolution : 0.1 Hz
setting) reading is 32.768 kHz
±
1Hz.
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.)
SMA-BNC (J) connector with
RF conversion connector
MB-860 board (B side)
CN305
Frequency
counter
Modulation
analyzer
AF OUT
RF IN
Spectrum
analyzer
MB-860 board (B side)
TONE
GND
CN305
Jumper wire
Connect a jumper wire between TONE land
and GND land by soldering.
(TONE signal : OFF)
SMA-BNC (J)
connector with
RF conversion connector