Service manual

Service Manual SD170E Series
Page 24 of 44
Flow Diagrams
Audio signal flow in Transmitter
Pre-emphasis
Audio Amp. & Filter
Level
Detector
300Hz HPF
Analog S/W
MC14053B
Data BPF
Sub-Audio LPF
MF6
Z1
Z
Y1
Y
Adj. Level
MCU
Check Audio In
Tone En
Audio In
Mod Out
Sub-Audio
Encoder
Y0
Z0
X1
X
X0
High : Audio In
Low : No Audio
300Hz HPF
Analog S/W
MC14053B
Sub-Audio LPF
MF6
Z1
Z
Y1
Y
MCU
Audio Mute
Y0
Z0
X1
X
X0
Pre-Selector
RF Board
Sub-Audio LPF
4th Order
AF
IF IC
SA605DK
RSSI
Audio Amp.
Comparator
MF6
Audio
Mute
Tone Detector
RSSI
Audio Out
LM386
Busy
Audio signal flow in Receiver
Audio signal flow diagram
Audio signal flow in Transmitter
Level
Detector
Analog S/W
MC14053B
Data BPF
Sub-Audio LPF
MF6
Z1
Z
Y1
Y
Adj. Level
MCU
Check Audio In
Tone En
Audio In
Mod Out
Sub-Audio
Encoder
Y0
Z0
X1
X
X0
High : Audio In
Low : No Audio
300Hz HPF
Analog S/W
MC14053B
Sub-Audio LPF
MF6
Z1
Z
Y1
Y
MCU
Audio Mute
Y0
Z0
X1
X
X0
Pre-Selector
RF Board
Sub-Audio LPF
4th Order
AF
IF IC
SA605DK
RSSI
Audio Amp.
Comparator
MF6
Audio
Mute
Tone Detector
RSSI
Audio Out
LM386
Busy
Audio signal flow in Receiver
Data signal flow diagram