Sony WRT-822B, Service Manual

Page: 21 / 46

3-13
WRT-822B
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
MM-SMA (J) connector (Part No. J-6402-480-A)
SMA-BNC (J) connector (Part No. J-6402-490-A)
Connections
(For connecting the DC power supply, refer to the “Preparations”
on page 3-2.)
Switch and Control Setting
The following setting is to be perform with the SET switch
(S402) , “
+
” switch (S400) and “
_
” switch (S401).
Transmitting Channel setting:
CE21 model; Group 00, 22-32 channel (482.000 MHz)
CE33 model; Group 00, 34-32 channel (578.000 MHz)
CE62 model; Group 00, 63-32 channel (810.000 MHz)
CE67 model; Group 00, 68-32 channel (850.000 MHz)
U14 model; 16-01 channel (482.125 MHz)
U30 model; 32-01 channel (578.125 MHz)
U62 model; 64-01 channel (770.125 MHz)
U66 model; 68-01 channel (794.125 MHz)
Attenuation setting: “Don't Care”
Accumulated time setting: “Don't Care”
MB-940 Board
(A side)
Spectrum analyzer
CN301
MM-SMA (J) connector with SMA-BNC (J) connector
Procedure
(1) 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
VBW (video band width):
300 kHz
ATT: 30 dB
(2) Check that the spurious emissions level (up to 5 GHz)
reading for the spectrum analyzer remains below
_
40
dBm.
20 dBm
_ 40 dBm
2.5 GHz (fc)
V : 10 dB/div
H : 500 MHz/div
Carrier frequency