4-40
8. If no failure is located from the previous checks, troubleshoot the power control circuitry.
A+ TO COMMAND BOARD
CURRENT SENSE +
CONTROL VOLTAGE LIMIT
CONTROL VOLTAGE DRIVE
RX MODE
LOCATION
LOW
TYP
1
—
2
3
4
10.8
13.8
5
0
6
10.8
13.8
7
8
—
9
10
10.8
13.8
11
9.4
12
10.8
1
0
2
3
0
October 28, 2002
2
1
3
K9.4
Figure 4-6. PA Test Adapter, 50 Watt Power Amplifier
Table 4-15. Power Control DC Voltage Chart
TX MODE
HI
LOW
TYP
—
—
—
—
0
0
2.0
0
2.0
7.0
16.6
10.4
13.4
0
0
9.2
9.4
16.6
10.4
13.4
0
1.2
—
—
—
—
0
1.5
3.5
16.6
10.4
13.4
9.6
9.9
9.4
9.6
9.8
13.1
0
0
0
0
3.2
0
0
0
Troubleshooting Procedures: Power Amplifier Procedures
4
6
8
10
7
11
5
9
HI
P0853
—
Key (no pin or wire)
3.2
Control Voltage Limit
9.2
Control Drive Voltage
16.2
Current Sense +
9.8
Keyed 9.4
16.2
A+ to Command Board
Temp Sense (cutback begins at 3.3 V)
v
Key (no pin)
5.0
Forward Detect Volt
16.2
A+ to Command Board
9.9
9.6-V Supply from Command Board
15.9
Current Sense - (voltage delta 150 mV)
U0500
0
0
Ground
Control AMP Input
0
0
Control AMP Input (not used)
A+ TO COMMAND BOARD
CURRENT SENSE -
12
FEMALE RECEPTACLE
CONNECTOR W 100 MIL
SPACING MATES TO P853
REGULATED 9.6V
V DETECT
TEMP SENSE
COMMENTS
6881076C25-D