Sony WRT-822B, Service Manual

Page: 18 / 46

3-10
WRT-822B
Procedure
(1) Set the spectrum analyzer as follows:
CENTER FREQUENCY(fc):
CE21 model; 470.125 MHz
CE33 model; 566.125 MHz
CE62 model; 798.125 MHz
CE67 model; 838.125 MHz
U14 model;
470.125 MHz
U30 model; 566.125 MHz
U62 model; 758.125 MHz
U66 model; 782.125 MHz
REFERENCE LEVEL: 20 dBm
FREQUENCY SPAN: 200 kHz (20 kHz/DIV)
RBW (resolution band width): 3 kHz
VBW (video band width): 1 kHz
ATT: 30 dB
(2) Adjust
1
RV201 so that level between carrier frequency
(frequency center level) on spectrum analyzer and tone
signal is within 29 dB
±
1 dB.
3-2-9. Tone Signal Adjustment
Equipment and Tools
DC power supply
DC output Voltage:
+
3.0
±
0.1 V dc
DC ammeter
Frequency counter
Spectrum analyzer
Modulation analyzer
MM-SMA (J) connector (Part No. J-6402-480-A)
SMA-BNC (J) connector (Part No. J-6402-490-A)
Switch and Control Setting
The following setting is to be perform with the SET switch
MB-940 Board
(A side)
Spectrum analyzer
CN301
MM-SMA (J) connector with SMA-BNC (J) connector
(S402) , “
+
” switch (S400) and “
_
” switch (S401).
Transmitting Channel setting:
CE21 model; Group 00, 21-01 channel (470.125 MHz)
CE33 model; Group 00, 33-01 channel (566.125 MHz)
CE62 model; Group 00, 62-01 channel (798.125 MHz)
CE67 model; Group 00, 67-01 channel (838.125 MHz)
U14 model; 14-01 channel (470.125 MHz)
U30 model; 30-01 channel (566.125 MHz)
U62 model; 62-01 channel (758.125 MHz)
U66 model; 66-01 channel (782.125 MHz)
Attenuation setting: 0 dB
Accumulated time setting: “Don't Care”
1. Frequency deviation adjustment
Connections
(For connecting the DC power supply, refer to the “Preparations”
on page 3-2.)
32.768 kHz
V : 10 dB/div
H : 20kHz/div
29 ± 1 dB
20 dBm
fc