Sony WRT-847A, Service Manual

Page: 28 / 54

3-12 WRT-847A/847B
3-2-11. Spurious Emissions Check
Equipment and Tools
DC power supply
DC output Voltage: + 3.0
±
0.1 V dc
DC ammeter
Spectrum analyzer
RF adjusting cable (Part No. J-6402-390-A)
RF conversion connector (Part No. J-6402-490-A)
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 spectrum analyzer to the antenna connector
(CN402) with RF adjusting cable (and RF conversion
connector).
(2) Set the spectrum analyzer as follows;
CENTER FREQUENCY: 2.5 GHz
REFERENCE LEVEL: 20 dBm
FREQUENCY SPAN: 5 GHz (500 MHz/DIV)
or Full span
RBW (resolution band width): 300 kHz
ATT: 20 dB
(3) Check that the spurious emissions level (up to 4 GHz)
reading for the spectrum analyzer remains below _ 38
dBm.
RF adjusting
cable
Spectrum analyzer
RF conversion
connector
DP-341 board RF-96 board
MB-914 board (A side)
CN402
20 dBm
_
40 dBm
2.5 GHz (fc)
5 GHz
V : 10 dB/div
H : 500 MHz/div
Carrier frequency