Codan Radio MT-3 User Manual
Page 33

MT-3 ANALOG RADIO SYSTEMS | USER GUIDE
Chapter 4: Analog System Block Diagrams Page 25
Figure 4-3: Analog / Digital Paging Transmitter Block Diagram
P
A
GING ENCODER
FM TRANSMITTER
P
A
GING MODULA
T
OR
RF OUT
AUDIO
PROCESSOR
RF POWER
AMPLIFIER
1 KHz TONE
@ -8.0 dBm
= 60% MAX. MOD.
2 LVL
DATA
4 LVL
DATA
PTT
OSCILLATOR
AGC PREAMP
& PRE-EMPHASIS
BALANCED
AUDIO
BALANCED
LEVEL
COMPRESSION
MAXIMUM
DEVIATION
DIR MOD
LEVEL
PTT
DIR
MOD
I/P
ANALOG
A / D
SEL
+1.6 KHz
-1.6 KHz
+4.8 KHz
-4.8 KHz
BESSEL
FILTER
BANDPASS
ADJUST
OCXO
10 MHz
PLL
INT /
EXT
REF
PHASE
CORRECTION
EXTERNAL
REFERENCE
A/D
SEL
I/P
LIMIT
ADJUST
REF
IN
REF IN
REF
OUT