TK-3178
(
L
)
20
6-2. Decode
■
QT/DQT
The output signal from IF IC (IC701) enters the micropro-
cessor (IC7) through IC11. IC7 determines whether the QT
or DQT matches the preset value, and controls the AM1
using IC5 and the speaker output sounds according to the
squelch results.
■
DTMF, MSK
The DTMF and MSK input signal from the IF IC (IC701) is
amplifi ed by IC10 and goes to IC13. The decoded informa-
tion is then processed by the MCU.
7. Power Supply
There are fi ve 5V and two 3.3V power supplies for the mi-
croprocessor: 5M, 5MS, 5C, 5R, 5T, 33M and 33MS.
5M and 33M is always output while the power is on. 5M
is always output, but turns off when the power is turned off
to prevent malfunction of the microprocessor.
5C is a common 5V and is output when SAVE is not set
to OFF.
5R is 5V for reception and output during reception.
5T is 5V for transmission and output during transmission.
6-2. 解码
■ QT/DQT
I F I C ( I C701) 的输出信号通过 I C11 送入微处理器 ( I C7)。
I C7 确认 Q T 或 D Q T 是否与预设值匹配，并用 I C5 控制 A M1，
然后扬声器根据静噪结果输出声音。
■ DTMF, MSK
IF IC(IC701) 的 DTMF 和 MSK 输入信号由 IC10 放大，然后
送入 IC13。然后由 MCU 处理解码信息。
7. 电源
微处理器 有 5 个 5V 电 源 和 2 个 3.3V 电 源。5M、5M S、5C、
5R、5T、33M 和 33MS。
电源打开时，5M 和 33M 总是输出。5M 总是输出，但电源关
闭时 5M 关闭，以防止微处理器出现故障。
5C 是普通的 5V 电源，它在 SAVE 没有设为 OFF 时输出。
5R 是接收用 5V 电源，它在接收期间输出。
5T 是发射用 5V 电源，它在发射期间输出。
CIRCUIT DESCRIPTION /
电路说明
