Sony WRT-800A, Руководство по обслуживанию

Страница: 19 / 40

WRT-800A (AU)
3-2-10. Battery Alarm Signal Check
Equipment and Tools
DC power supply
DC output voltage:
+
1.5
±
0.1 Vdc
DC current meter
Frequency Counter
Spectrum analyzer
Modulation analyzer
RF adjusting connector (See page 3-2.)
1. Frequency deviation check
Connections
(For connecting the DC supply, refer to the “Preparations”
on page 3-3.)
Switch and control setting
S301, S302, S303, S304/ RF-87 board (A-side)
WRT-800A S301 S302 S303 S304 Channel
setting
AU66 model _ 0 1 OFF 67-01
Procedure
(1) Set the spectrum analyzer as below:
CENTER FREQUENCY (fc) : 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
(2) Decrease gradually the DC output voltage of the DC
regulated power supply and confirm that the battery
alarm signal turns on at 1 V
±
0.1 V.
(3) Check that level difference between carrire frequency
(center frequency level) on spectrum analyzer and
battery alarm signal is within 29 dB
±
1 dB.
RF adjusting connector
SMA-BNC
conversion connector
RF-87 Board
(B side)
AU-258 Board
(A side)
Spectrum analyzer
Connect a jumper wire
between TONE land and
GND land by soldering.
(TONE signal OFF)
TONE
3-10
20 dBm
29 dB ± 1 dB
V : 10 dB/div
H : 20 kHz/div
fc
32.782 kHz