Motorola APX 1000 - Page 708

3-4 Theory of Operation: Main Board
Figure 3-3. Transceiver (UHF1) Block Diagram (Power and Control Omitted)
FGU
Transmitter
Receiver
2nd
LO
Termination
Antenna Switch
coupler
Rev
Power
Detector
Current
Sense
FET
TRIDENT IC
LOOP
FILTER
PRESCALAR
BUFFER
RX SSI Data
16.8MHz
BUFFER
PRE
BUFFER
TX LO
TX
BUFFER
TX
RX
16.8MHz
RX SSI Clock
RX SSI Frame Sync
Indicates Sub-shield
Harmonic
Filter
Driver
Amplifier
Abacus
IF Filter
15dB Step Attn
RX VCO
TX VCO
UHF1
LNA
UHF1
Mixer
Circuit
Current
Sensor
Batt. DC Supply
o
DC Supply to FET PA & Driv. Amp.
Power Control Voltage (Vctrl)
UHF
RX LO
GPS