Kenwood NX-220 Service Manual page 24

NX-220
9. Compander Circuit
The term "compander" means compressor and expand-
er. The compander reduces noise by utilizing a compressor
and an expander. The transceiver contains a DSP (IC603) to
perform this operation. The transceiver compander can be
turned on or off using the FPU.
+B
24
CIRCUIT DESCRIPTION /
TX-RX unit
F1
2.5A
F2
1.0A
VOL/SW
IC507
5.6V Det
IC506
38M
IC504
50C
Q501
SB2
CN2
Display unit
CN5
Fig. 7 Power supply circuit / 图 7 电源电路
电路说明
9. 压扩器电路
"compander"一词表示压缩器和扩展器。压扩器利用压缩
器和扩展器减低噪音。手持对讲机包含 D S P ( I C603)，用以执
行此操作。可用 FPU 开启或关闭手持对讲机的压扩器。
Q902
SW
IC902
50V
/PSW
/BINT
IC501
33A
IC502
33M
IC503
15M
IC505
33C
IC509
100C
Q505
50T
Q503
50R
Q512
50CS
Ripple
filter
Final AMP, APC
AFPA
2-pin Jack
ASIC
IC610
DSP, FLASH, SRAM
DSP
PLL, TCXO
Assist Circuit
(B540-11-042E)
ASSIST
TX circuit
RX circuit
PLL, fin
VCO
AF circuit
AF circuit, DAC
IC8
LCD driver
SQL circuit
LED