Sony WRT-847A, Service Manual

Page: 20 / 54

3-4 WRT-847A/847B
3-2-2. Carrier Frequency Adjustment
Equipment and Tools
DC power supply
DC output voltage: + 3.0
±
0.1 V dc
DC ammeter
Frequency counter
RF adjusting cable (Part No. J-6402-390-A)
RF conversion connector (Part No. J-6402-490-A)
Adjustor (Part No. 7-721-052-81)
Connections
(For connecting the DC power supply, refer to the “Prepara-
tion” on page 3-2.)
Switch and Control Setting
Perform the same setting as described in “4. Switch and Con-
trol Setting during Adjustment and Checking,” on page 3-3.
Procedure
(1) Connect the frequency counter to the antenna connector
(CN403) with RF adjusting cable (and RF conversion
connector).
(2) Adjust 1 CT201 on the DP-341 board so that the frequency
counter reading meets the following specification.
Specification: Carrier frequency mentioned in the table
below.
WRT-847A/B Carrier frequency
U14 model 482.125 MHz
±
1 kHz
U30 model 578.125 MHz
±
1 kHz
U62 model 770.125 MHz
±
1 kHz
U66 model 794.125 MHz
±
1 kHz
CE21 model 482.000 MHz
±
1 kHz
CE33 model 578.000 MHz
±
1 kHz
CE62 model 810.000 MHz
±
1 kHz
CE67 model 850.000 MHz
±
1 kHz
AU66 model 799.250 MHz
±
1 kHz
Adjustment: 1 CT201/DP-341 Board (A side)
3-2-3. RF Power Output Adjustment
Equipment and Tools
DC power supply
DC output voltage: + 3.0
±
0.1 V dc
DC ammeter
Power meter (with power sensor)
RF adjusting cable (Part No. J-6402-390-A)
RF conversion connector (Part No. J-6402-490-A)
Adjustor (Part No. 7-721-052-81)
Connections
(For connecting the DC power supply, refer to the “Prepara-
tions” on page 3-2.)
Switch and Control Setting
First, Perform the same setting as described in “4. Switch and
Control Setting during Adjustment and Checking,” on page 3-
3, then perform the following setting:
RF power setting:“H” (= 50 mW)
Procedure
(1) Connect the power meter (with power sensor) to the an-
tenna connector (CN402) with RF adjusting cable (and
RF conversion connector).
(2) Adjustment
Specification: Power meter = Maximum
Adjustment: 1 CT401/RF-96 Board (A side)
(3) Adjustment
Specification: Power meter = 50
+
10
mW
Adjustment: 1 RV401/RF-96 Board (A side)
(4) Set the RF power setting to “L” (= 10 mV), and check the
power meter reading meets the following specification.
Specification: Power meter = 11
±
5 mW
DP-341 board RF-96 board
Power meter
Power sensor
RF adjusting cable
RF conversion connector
CN402
MB-914 board (A side)
1 1
RV401 CT401
_ 15
DP-341 board
RF-96 board
Frequency counter
RF adjusting
cable
CN402
RF conversion
connector
MB-914 board (A side)
1
CT201