Motorola APX 1000 Detailed Service Manual page 710

3-6
Termination
GPS
Rev
Power
Detector
800
700
Figure 3-5. Transceiver (700/800 MHz) Block Diagram (Power and Control Omitted)
Batt. DC Supply
Current
Current
Sense
Sensor
Circuit
DC Supply to FET PA & Driv. Amp.
Harmonic
Filter
coupler
o
15dB Step Attn
16.8MHz
TRIDENT IC
PRESCALAR
BUFFER
16.8MHz
BUFFER
800
LNA LNA
700
Power Control Voltage (Vctrl)
Antenna Switch
FET
7800
VCO 1 (740-776 MHz)
LOOP
FILTER
VCO 2 (794-824 MHz)
VCO 3 (851-885 MHz)
PRE
BUFFER
IF Filter
Mixer
HPF
Theory of Operation: Main Board
Indicates Sub-shield
Driver
Amplifier
TX
TX
BUFFER
TX LO
RX
RX LO
RX SSI Data
Abacus
RX SSI Frame Sync
2nd
LO
FGU
Transmitter
Receiver
RX SSI Clock