Kenwood TK-3148 Service Manual

Also see for TK-3148: Service manual

Contents

TK-314816CIRCUIT DESCRIPTION / 电路说明Fig. 10 Memory circuit / 图 10 存储器电路IC309IC308CPUIC310EEPROMFLASH6-2. Low battery warningThe battery voltage is monitored by the microprocessor(IC309). When the battery voltage falls below the voltage setby the Low Battery Warning adjustment, the red LED flashesto notify the operator that it is time to replace the battery. Ifthe battery voltage falls even more (approx. 6.1V), a beepsounds and transmission is stopped.Low battery warningThe red LED flashes duringtransmissionThe red LED flashes andcontinuous beep soundswhile PTT pressedBattery conditionThe battery voltage is low butthe transceiver is still usable.The battery voltage is low andthe transceiver is not usableto make calls.6-2．电池低压告警通过微处理器（IC309）监视电池电压。当电池的电压低于通过电池低压告警调整设定的电压时，红色指示灯闪烁以提示操作者更换电池。如果电池的电压继续降低（大约 6.1V），则发出beep 音并停止发送。电池低压告警电池状态发射过程中红色指示灯闪烁。电池电压降低但仍可使用手持机。当按下 PTT 键时红色指示灯闪电池电压降低不能使用手持烁并且手持机发出连续 beep 音。机发出呼叫。6. Control CircuitThe control circuit consists of microprocessor (IC309) andits peripheral circuits. It controls the TX-RX unit and transfersdata to and from the display unit. IC309 mainly performs thefollowing;1) Switching between transmission and reception by PTTsignal input.2) Reading system, group, frequency, and program datafrom the memory circuit.3) Sending frequency program data to the PLL.4) Controlling squelch on/off by the DC voltage from thesquelch circuit.5) Controlling the audio mute circuit by decode data input.6) Transmitting tone and encode data.6-1. Memory circuitMemory circuit consists of the CPU (IC309) and a flashmemory (IC308), a flash memory has a capacity of 4M bitsthat contains the transceiver control program for the CPU anddata such as transceiver channels and operating features.This program can be easily written from an external devices.Data. such as operating status, are programmed into theEEPROM (IC310).● Flash MemoryNote : The flash memory stores the data containing the FPU(KPG-74D CPS) program, Security Number (MPT SerialNumber) and firmware program (User mode, Test mode,Tuning mode, etc.).This data must be reinstalled when replacing the flash memory.● EEPROMNote : The EEPROM stores tuning data (Deviation, Squelch,etc.). Realign the transceiver after replacing the EEPROM.6．控制电路控制电路由微处理器（IC309）和其外围电路组成。微处理器控制TX-RX单元和发送到显示单元的数据以及从显示单元发送的数据。IC309 主要执行下述功能∶1) 通过 PTT 信号输出在发射和接收之间转换。2) 从存储器电路读取系统，组，频率和编程数据。3) 向 PLL 发送频率编程数据。4) 通过来自于静噪电路的直流电压控制静噪的开启 / 关闭。5) 通过解码数据输入控制音频静音电路。6) 发送音频和编码数据。6-1．存储器电路记忆电路由 CPU (IC309) 和一块闪存（IC308）组成。闪存容量 4MB，载有 CPU 所需的收发机控制程序以及收发机信道、功能设置等数据。可以方便地使用外部设备写这个程序。工作状态等数据编写在 EEPROM (IC310)中。● 闪存注释∶闪存保存的数据包括 FPU（KPG-74D CPS）程序，安全码（MPT序列号）和固件编程（用户模式，测试模式，调谐模式等）。当更换闪存时，必须重新安装数据。● EEPROM注释∶EEPROM 保存调谐数据（频偏，静噪）。更换 EEPROM 后重新调校手持机。