Table 4-8. Power Control Dc Voltage Chart - Motorola ASTRO Digital Spectra Plus Detailed Service Manual

Troubleshooting Procedures: Power Amplifier Procedures
If it is verified that both power set and current limit are not related to the power problem, then the
synthesizer output must be checked. A milliwatt meter connected to the TX injection cable should
indicate at least 10 mW of injection power during key-up. If this is not the case, refer to the RF board
and VCO sections of this manual for troubleshooting procedures.
RX MODE
LOCATION
LOW
J1
1
2
3 10.8 13.6
4 0
5 10.8 13.6
6
7 –
8
9 10.8 13.6
10 9.4
11 10.8 13.6
12 –
U500
1 0
2
3 0
4
5
6 1.5
7
8
9
10
11
12
6881076C25-E

Table 4-8. Power Control DC Voltage Chart

TX MODE
TYP HI LOW TYP
0 0 2.0
0 2.0 7.0
16.5 10.0 13.0
0 0 9.2 9.4
16.5 10.0 13.0
0 1.2
– – –
0 13.0 9.3
16.5 10.0 13.0
9.6 9.9 9.4 9.6
16.5 9.8 12.8
– – –
0 0 0
0 3.2
0 0 0
0 0
9
3.0 4.5 1.5 3.0
0 1.5 3.0
0 1.3 3.5
0 1.3 3.5
0
0 1.3 3.5
0 0 1.2
HI
3.2 Control Voltage Limit
10.0 Drive Voltage
16.0
Current Sense +
9.8 Keyed 9.4
16.0 A+ to Command Board
Temp Sense (cutback begins at 3.3-V)
– –
Key (no pin)
5.0 Forward Detect Voltage
16.0 A+ to Command Board
9.9
9.6-V Supply from Command Board
Current Sense
15.8
– –
Key (no pin or wire)
0 0 Ground
Control AMP Input
0 0 Control AMP Input (not used)
2 3.2
Control Voltage Limit (cutback at 3.3 V)
0 N.C.
4.5 Power Set from D-A (max power at 1.5 V)
4.5
Power Set Buffer Out
6.0
Coupler Buffer Out
6.0 Forward Detect Volt
0 Reflected Power Detect (not used)
6.0 Same as pin 8 (not used)
6.0
Thermister Buffer out (increases as PA gets hot)
COMMENTS
–
(voltage delta 150 mV)
September 5, 2008
4-23