Kenwood TK-3360 Service Manual page 15

5-1. Frequency Shift Circuit
The MCU (IC809) operates at a clock frequency of
12.0MHz. This oscillator has a circuit that shifts the frequen-
cy via Beat shift switch (Q806, Q807).
A beat sound may be able to be evaded form generation
if "Beat Shift" is set to ON when it is generated in the in-
ternal spurious transmission modulated sound of the trans-
ceiver.
5-2. Memory Circuit
The Memory circuit consists of the MCU (IC809) and an
EEPROM (IC810). The EEPROM has a capacity of 64k bits
that contains the transceiver control program for the MCU
and data such as transceiver channels and operating fea-
tures.
■ EEPROM
Note:
The EEPROM stores tuning data (Deviation, Squelch,
etc.).
Realign the transceiver after replacing the EEPROM.
5-3. Low Battery Warning
The battery voltage is monitored by the MCU (IC809 pin
86: BATT). When the battery voltage falls below the volt-
age set by the Low Battery Warning adjustment during the
transmission, the red LED blinks to notify the operator that
it is time to replace the battery (When the "On TX" option
(default setting) under the Battery Warning /status function
in the FPU is selected.). If the battery voltage falls below 5.9V,
the transceiver does not transmit and the warning tone
beeps while the PTT switch is pressed.
Low battery warning
The red LED blinks during trans-
mission.
The red LED blinks and the
warning tone beeps while the
PTT switch is pressed.
CIRCUIT DESCRIPTION /
BSHIFT
9
C846
H: OFF
L: ON
Q806
Fig. 7 Frequency shift circuit / 图 7 频率偏移电路
IC809
MCU
Fig. 8 Memory circuit / 图 8 存储电路
Battery status
The battery voltage is low but
the transceiver is still usable.
The battery voltage is low and
the transceiver cannot be used
to make calls.
电路说明
5-1. 频率偏移电路
微处理器 ( I C809) 在 12.0M H z 时钟下工作。此振荡器有可
以被拍频偏移开关 (Q806,Q807) 变换频率的电路。
如果"拍频偏移"被设定为 ON，可以避免产生拍频声音。
IC809
MCU
XOUT XIN
11 13
X802
C854
Q807
5-2. 存储电路
存储电路由微处理器 (IC809) 和 EEPROM(IC810) 组成。有
64kbits 的容量，包含 MCU 用的手持对讲机控制程序以及信道
和操作功能这样的数据。
IC810
EEPROM
■ EEPROM
注意 :
EEPROM 保存调谐数据 ( 频偏、静噪等 )。
更换 EEPROM 后，请重新校正手持对讲机。
5-3. 低电池电量警告
电池电压由微处理器 (IC809 针脚 86:BATT) 监控。 发射期间，
当电池电压低于低电池电量警告调节设置的电压时，红色 LED
闪烁，通知操作者应该更换电池了 ( 当选择了 FPU 电池告警 /
状态功能下的"On TX( 发射时 )"选项 ( 默认 ) 时 )。如果电
池电压低于 5.9V，按下 P T T 开关时手持对讲机不发射并响起
警告音。
低 电 池 电 量 警 告
发射期间红色 LED 闪烁。
按下 PTT 开关时，红色 LED 闪
烁并响起警告音。
TK-3360
电 池 状 态
电池电压低，但手持对讲机仍
能使用。
电池电压低，不能使用手持对
讲机进行呼叫。
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