Sony WRT-807B, Service Manual

Page: 25 / 64

3-9
WRT-807B (U/CE)
(5) Reads the indication on the audio analyzer (level
meter).
Set the SENSITIVITY on the audio analyzer (level
meter) so that the audio analyzer (level meter) reads 0
dB.
(6) Switch the oscillation frequency for the audio analyzer
(oscillator) from 1 kHz to 100 Hz.
(7) Check that audio analyzer (level meter) reading is
+
1.5
±
1.0 dB.
(Indication level is + 1.5
±
1.0 dB as compared with the
read level of procedure (5) above.)
(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
+
1.8
±
1.0 dB (for CE57/CE62/CE67 model)/
+
0.6
±
1.0 dB (for U30/U42/U62/U66 model).
(Indication level is + 1.8
±
1.0 dB (for CE57/CE62/
CE67 model) / + 0.6
±
1.0 dB (for U30/U42/U62/U66
model) 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 (for CE57/CE62/CE67 model)/
+ 0.5
±
1.0 dB (for U30/U42/U62/U66 model).
(Indication level is _ 4.7
±
2.0 dB (for CE57/CE62/
CE67 model)/
+
0.5
±
1.0 dB (for U30/U42/U62/U66
model) 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 :
+
1.5
±
0.1 Vdc
DC ammeter
Frequency counter
Spectrum analyzer
Modulation analyzer
SMA-BNC (J) connector (Part No. J-6402-490-A)
RF conversion connector (Part No. J-6402-400-A)
Switch and Control Setting
Same as “Switch and Control Initial Setting” on page 3-3.
1. Frequency deviation adjustment
Connections
(For connecting the DC power supply, refer to the “Prepara-
tion” on page 3-2.)
Procedure
(1) Connect the spectrum analyzer to the antenna connector
(CN305) with SMA-BNC (J) connector (and RF con-
version connector).
(2) Set the spectrum analyzer as follows:
CENTER FREQUENCY (fc):
CE57 model ; 770.000 MHz
CE62 model ; 810.000 MHz
CE67 model ; 850.000 MHz
U30 model ; 578.125 MHz
U42 model ; 650.125 MHz
U62 model ; 770.125 MHz
U66 model ; 794.125 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 : 20 dB
(3) Adjust
1
RV301 on the MB-860 board(B side) so that
level between carrier frequency (frequency center level)
on spectrum analyzer and tone signal is within 29 dB
±
1dB.
Spectrum
analyzer
MB-860 board (B side)
CN305
RV301
SMA-BNC (J) connector with
RF conversion connector
fc
32.768 kHz
V : 10 dB/div
H : 20 kHz/div
29 ± 1 dB
20 dBm