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■ Unlock Circuit
During reception, the 8RC signal goes high, the 8TC sig-
nal goes low, and Q29 turns on. Q31 turns on and a voltage
is applied to the collector (8R). During transmission, the
8RC signal goes low, the 8TC signal goes high and Q30
turns on. Q33 turns on and a voltage is applied to 8T.
The CPU in the control unit monitors the PLL (IC1) LD
signal directly. When the PLL is unlocked during transmis-
sion, the PLL LD signal goes low. The CPU detects this
signal and makes the 8TC signal low. When the 8TC signal
goes low, no voltage is applied to 8T, and no signal is trans-
mitted.
Transmitter System
■ Outline
The transmitter circuit produces and amplifies the de-
sired frequency directly. It FM-modulates the carrier signal
by means of a varicap diode.
■ Power Amplifier Circuit
The transmit output signal from the VCO passes through
the transmission/reception selection diode (D19) and ampli-
fied to a specified level of the power module (IC101) by the
drive block (Q23 and Q25). The amplified signal goes to a
low-pass filter. The low-pass filter removes unwanted high-
frequency harmonic components, and the resulting signal is
goes the antenna terminal.
MIC
IC21(1/2)
MIC/IDC
NJM2100V
MIC KEY
INPUT
IC3
D/A
CONVERTER
2SK508NV
M62363FP
X1
IC1
TCXO
16.8MHz
MB15A02
CIRCUIT DESCRIPTION / 电路说明
Q31
8R
SW
Q29
SW
8RC
Fig. 7 Unlock circuit / 图7 失锁电路
IC22
IC4
Splatter
SUM AMP
FILTER
CONVERTER
NJM2902V
NJM2904V
M62363FP
IC3
IC6
D/A
CPU
CONVERTER
784214GC
M62363FP
Q11
Q15
IC23
1/2
VCO
BUFFER
DIVIDER
2SC5108
UPB1509GV
(K52)
(Y)
Q3
RF AMP
PLL
2SC4649
(N,P)
Fig. 8 Transmitter system / 图8 发射部系统
■ 失锁电路
在接收的过程中， 8RC信号为高电平， 8TC信号为低电平， 并
且 Q29 导通。Q31 导通并且向集合器（8R）提供电压。在发射
过程中，8RC 信号为低电平，8TC 信号为高电平，并且 Q30 导
通。Q33 导通并且向 8T 提供电压。
控制单元中的 CPU 直接监听锁相环电路（IC1）LD 信号。当
发射过程中锁相环电路失锁时， 锁相环电路 LD 信号为低电平。
CPU 检测此信号并使 8TC 信号变为低电平。当 8TC 信号为低电
平时，不向 8T 提供电压，并且不发射任何信号。
8C
Q33
8T
SW
Q30
SW
8TC
LD
IC6
IC1
CPU
PLL
PLL lock
: LD "H"
发射部系统
■ 概要
发射部电路直接产生和放大需要的频率。 通过各色二极管的
含义对载波信号进行频率调制。
■ 功率放大器电路
来自于压控振荡器的发射信号经过发射/接收选择二极管
(D19) 并通过驱动装置(Q23和Q25)被放大为功率模组(IC101)的
一个特定电平。 被放大的信号进入一个低通滤波器。此低通滤
波器消除不需要的高频谐波成份，获得的信号进入天线终端。
IC3
IC4
D/A
BUFFER
NJM2902V
Q20
Q23
RF AMP
RF AMP
2SC4649
2SC3357
(N,P)
TK-7108
ANT
Q25
IC101
POWER AMP
RF AMP
M67741H-32
2SC2954
19
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