Motorola Astro XTL 1500 - Figure 4-1. Frequency Generator Unit DC Power Supply Distribution (VHF)

June 15, 2005 6815854H01-A
4-8 Troubleshooting Procedures: VHF (136–174 MHz) Band Main Board Troubleshooting
Figure 4-1. Frequency Generator Unit DC Power Supply Distribution (VHF)
MAEPF-27803-O_VHF
13.8 VDC
from Battery or
Power Supply
Q0503
Switched A+
Switched A+
(SW_A+)
9.3V
Regulated
5.0V
Regulated
8.2V
Regulated
K9.1
3.0V
Regulated
U0950
9.3V Regulator
U0505
5.0V Regulator
U3750
3.0V Regulator
Y3750 16.8
MHz Reference
Oscillator and
U3752 Buffer
Q3756
8.2V Superfilter
Q3753,Q3754
TX VCOs
and
Q3751,Q3752
RX VCOs
U3751
LVFracN
Q3762 3rd
Stage of RX
Injection
Q3761 1st
Stage of RX
Injection
U0951
9.1V TX
Regulator
Q3760 and
Q3759 TX
Injection
Q0952
K9.1 Switch
Q3758 3rd
Ste of TX
Injection
Charge Pump
Bias Q3755 and
Q3750, Prescaler
Amp Q3757
Q3758 3rd
Stage of TX
Injection
Q3769 2nd
Stage of RX
Injection