Tait TP9100 - Page 197

TP9100 Service Manual Frequency Synthesizer Fault Finding 197
© Tait Electronics Limited May 2005
Figure 9.14 Measurement points for the VCO and related circuitry in VHF radios
+4V3 DEC
PIN 3 OF
Q5003
PIN 3 OF
Q5003
TX 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
Q5000
D510
5 V SWITCH
TR SWITCH
SYN TX LO
SYN RX LO1
TRANS- MITTER
RECEIVER
DIGITAL
CIRCUITRY
DIG SYN TR SW DIG SYN EN
+14 V
INVERTER
R544
JUNCTION OF
C541 AND R547
JUNCTION OF
C541 AND R547
+3V0 AN
L506
3V
SUPPLY
D510
IC506
L525
D515D510
L5001
L524
IC404
5V
SUPPLY
+5V AN