Codan Radio Communications VT-3-150-SN User Manual
Audio Processor Board Instruction Manual
1-3
1.2
Block Diagram (FM Audio Processor)
Splatter
Filter
Pre-
emphasis
Select
Pre-
emphasis
Select
Compression
Amp
Compression
Amp
Limiter/Summing
Amplifier
Buffer
+4V
Regulator
+4V
Pre-
emphasis
Select
Auxillary
Buffer
Amp
Tx Audio
Control
Audio
Switch 1
Audio
Switch 2
Switch 2
Regular Modulation
Buffer
Subtone
1
3 KHz
Direct Modulation
Offset Buffer
TCVCXO
Modulation Buffer
Offset
TCVCXO
DC Level
DC Level
Adjust
Reg Mod
Out
Low Freq
Out
Inverting Amp
Coupling
Select
2 Port
Polarity
Select
JU35
JU34
Tx Audio
Control
Wide/Narrow
Band Select
Data/Voice
Select
3dB
Narrow
Band
Pad
JU14
JU26
JU27
JU30
JU43
JU28
JU25
49K9
49K9
P1-3
R2
U1A
U1B
P1-1
R31
Tone
Digital
Input
P2-1
Balanced
Input
Microphone
Input
U3A
U3B
U2A
U2C
U2D
P2-2
R48
R42
U5
U6
Q1
Direct
Modulation
Input
Modulation
Input
P4-3
U2B
R87
P4-4
P4-2
P3-1
U3C
U3D
P4-1
JU4
Subtone
2
JU13
R36
JU12
JU11
Figure 1
Block Diagram - Audio Processor