Service Manual

CIRCUIT DESCRIPTION
4-3
Part No. 001-3474-002
Figure 4-1 DATA TRANSCEIVER BLOCK DIAGRAM
Z201
RF AMP
Q201 Z202
MIXER
CRYSTAL FILTER
PREDRIVER
Q501
DRIVER FINAL
ANTENNA
SWITCH
RX AUDIO
VCO
+5V
+5V
+7.5V
+7.5V
RECEIVE
TRANSMIT
LOCK
ENABLE
DATA
CLOCK
AMPLIFIER
+5V
T/R PS
NEG SUP
RECEIVER
TRANSMITTER
SYNTHESIZER
VCO
BUFFER/
RSSI
ANTENNA
LOW-PASS
FILTER
RF OUT
RF BPF RF BPF
U221
Z221/Z222
52.95 MHz
Q222
IF / 450 kHz FILTER
Q521 Q541 CR561/562,
U542
Q401
2nd LO AMP
1st LO AMP
Q851
CLV
Q853
Q851/Q852
AMPLIFIER
RSSI
RX OUT
TX IN Y801
TCXO
MOD INPUT
MOD ADJUST
SYNTH OUT
RF IN
U801
Q833
Q101, Q102
Q831, Q832
Q834
BUFFER
U241
U251Q301
IF AMP
Q221
Q850