3-6
TROUBLESHOOTING TABLES
4.0
Troubleshooting Table for Board and IC Signals
IC Designator
Pin
Pin Function
DC Voltage
Comments (Condition)
U51
IFIC
1
RF input 44.85 MHz
1.20
2
RF input decoupling
1.20
3
2nd LO osc output
4.02
4
2nd LO osc input
4.60
5
RSSI output
0.74
(no received signal)
6
Vcc
4.70
7
Audio feedback
0.89
8
Audio output
1.44
DEMOD to stage U510
9
RSSI feedback
0.74
(no received signal)
10
Quad detector input
2.22
11
Limiter output
1.25
12
Limiter decoupling 2
1.30
13
Limiter decoupling 1
1.30
14
Limiter input
1.28
15
Ground
GND
16
IF amp output
1.22
17
IF amp decoupling 2
1.26
18
IF amp input
1.26
19
IF amp decoupling 1
1.26
20
2nd mixer output
3.09
U52
BW Select Switch
1
Inverter 1 input
0
(25 kHz mode)
2
Inverter 2 output
0
(25 kHz mode)
3
Inverter 3 input (NU)
GND
4
Ground
GND
5
Inverter 3 output (NU)
4.96
6
Inverter 2 input
3.00
(25 kHz mode)
7
Inverter 1 output
4.95
(25 kHz mode)
8
Vcc
4.96
Содержание CP040
Страница 1: ...Commercial Series CP040 Radios UHF1 403 440MHz Service Information Issue October 2004 ...
Страница 4: ...iv ...
Страница 8: ...1 4 MODEL CHART AND TECHNICAL SPECIFICATIONS ...
Страница 32: ...3 16 TROUBLESHOOTING TABLES ...
