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August 16, 2007
6816985H01-B
3.1-2
VHF Radio Power:
B+ Routing for VHF Band Main Board
3.1.4 B+ Routing for VHF Band Main Board
Refer to
and the appropriate schematic diagram in the back of this manual.
Raw B+ (7.5V) from the battery enters the radio through a 3-contact connector (B500). From B500 it
is routed through a ferrite bead (E500) to the fuse (F500) where RAW_B+ is distributed to the
transmitter and the RF section is supplied by .
provides power to the following:
• the mechanical switch (S501)
• the radio’s LED (D501)
• the voltage regulator (U503), which charges the lithium battery
and the voltage regulator (U702); then routes through the connector (J601, pin 3). U702 will be
discussed in the B+ and +5V routing for the voice encoder (vocoder) and controller (VOCON)
section.
During the transmit mode, routes through a ferrite bead (E101) to the Power Control IC
(PCIC) (U102), the RF driver (U101), through another ferrite bead (E102) to the final power amplifier
(Q101). also routes through the Field Effect Transistor (FET) switch (Q702) where it
becomes SW_B+. SW_B+ powers a 5V linear regulator (U500), which supplies 5V to the PCIC
(U102).
During the receive mode, the linear regular (U500) provides 5V to the mixer (U1) and the ABACUS
III IC (U401). U500 also provides 5V to the Frequency Generation Unit’s (FGU) FracN (U201) and
VCOs.
Figure 3.1-1. B+ Routing for VHF Main Board
Mixer
(U1)
LNA
(Q1)
ABACUS III
(U401)
5V
DIG_3V
ANA_3V
ANA_3V
5V
Receiver
Battery
FRAC N
(U201)
VCO’s
5V
ANA_3V
5V
FGU
VSF
PCIC
(U102)
DRIVER & PA
(Q101)
RAW_B+
5V
5V
5V
ABACUS_3V
ANA_3V
VSW1
SW_B+
5V
Transmitter
Fuse B+
(F500)
Ferrite Bead
(E500)
TX Linear 5V
Regulator
(U500)
Analog 3V
Regulator
(U501)
Digital 3V
Regulator
(U502)
MAKO
(U701)
Summary of Contents for ASTRO MT 1500
Page 4: ...iv Table of Contents August 16 2007 6816985H01 B Notes ...
Page 164: ...August 16 2007 6816985H01 B 5 6 Troubleshooting Procedures Operational Error Codes Notes ...
Page 188: ...August 16 2007 6816985H01 B 6 1 24 VHF Troubleshooting Charts Secure Hardware Failure Notes ...
Page 212: ...August 16 2007 6816985H01 B 6 2 24 UHF1 Troubleshooting Charts Secure Hardware Failure Notes ...
Page 236: ...August 16 2007 6816985H01 B 6 3 24 UHF2 Troubleshooting Charts Secure Hardware Failure Notes ...
Page 710: ...9 2 40 UHF1 Schematics Board Overlays and Parts Lists August 16 2007 6816985H01 B Notes ...
Page 806: ...9 5 32 900MHz Schematics Board Overlays and Parts Lists August 16 2007 6816985H01 B Notes ...
Page 816: ...Index 4 August 16 2007 6816985H01 B Notes ...
Page 817: ......