Tait TM8100 mobiles - Page 225

TM8100/TM8200 Service Manual Frequency Synthesizer Fault Finding 225
© Tait Electronics Limited November 2007
Figure 9.13 Measurement points for the VCO and related circuitry in VHF radios
+5V DEC
PIN1OF
D5004
PIN 1 OF
D5004
PIN3OF
Q5003
PIN 3 OF
Q5003
PIN2OF
Q5001
PIN 2 OF
Q5001
PIN2OF
D5004
PIN 2 OF
D5004
TX PORT
TX PORT
RX PORT
RX PORT
SIGNAL TYPES
RF ANALOG CLOCK DIGITAL
PLL
LOOP
FILTER
AND
SUMMER
FILTERING
OF SUPPLY
FOR VCO
CIRCUITRY
FREQUENCY SYNTHESIZER
PLL FEEDBACK
VCO
BUFFER
AMPLIFIER
AND
COUPLER
D5004
5 V SWITCH
TR SWITCH
SYN TX LO
SYN RX LO1
TRANS- MITTER
RECEIVER
DIGITAL
BOARD
DIG SYN TR SW DIG SYN EN
INVERTER
VIA TO CHECK
DIG SYN TR SW
VIA TO CHECK
DIG
SYN TR SW
R103
R544
JUNCTION OF
C541 AND R547
JUNCTION OF
C541 AND
R547
+3V0 AN
L506
3V
SUPPLY