Sony WRT-847A, Service Manual

Page: 25 / 54

3-9 WRT-847A/847B
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 (fc):
U14 model; 482.125 MHz
U30 model; 578.125 MHz
U62 model; 770.125 MHz
U66 model; 794.125 MHz
CE21 model; 482.000 MHz
CE33 model; 578.000 MHz
CE62 model; 810.000 MHz
CE67 model; 850.000 MHz
AU66 model; 799.250 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: 20 dB
(3) Adjust 1 RV301 on the MB-914 board (B side) so that
level between carrier frequency (frequency center level)
on spectrum analyzer and tone signal is within 29 dB
±
1
dB.
fc
32.768 kHz
V : 10 dB/div
H : 20 kHz/div
29
±
1 dB
20 dBm
(8) Next, switch the oscillation frequency for the audio ana-
lyzer (oscillator) from 100 Hz to 10 kHz.
(9) Check that the reading for the audio analyzer (level
meter) is + 2.1
±
1.0 dB.
(Indication level is + 2.1
±
1.0 dB as compared with the
read level of procedure (5) above.)
(10)Next, switch the oscillation frequency for the audio ana-
lyzer (oscillator) from 10 kHz to 15 kHz.
(11)Check that the reading for the audio analyzer (level
meter) is _ 4.7
±
2.0 dB.
(Indication level is
_
4.7
±
2.0 dB as compared with the
read level of procedure (5) above.)
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
RF adjusting cable (Part No. J-6402-390-A)
RF conversion connector (Part No. J-6402-490-A)
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)
1. Frequency deviation adjustment
Connections
(For connecting the DC power supply, refer to the “Prepara-
tions” on page 3-2.)
DP-341 board RF-96 board
RF adjusting
cable
Spectrum analyzer
RF conversion
connector
RV301 (B side)
MB-914 board (A side)
CN402
1
http://getMANUAL.com