Kenwood TK-2317 Service Manual

Also see for TK-2317: Service manual Specification Instruction manual Instruction manual

Contents

TK-231728■ High-speed data (2-tone)High-speed data (HSD) is output from pin 3 of the MCU.HSD deviation made by an adjustment in the MCU is passedthrough the low pass CR fi lter and then applied to the base-band (IC812).The signal is mixed with the audio signal and goes to theVCO and TCXO.■ MSK/DTMFThe MSK/DTMF signal is generated in the baseband IC(IC812). The signal passes through the D/A converter (in-side the baseband IC812) and is routed to the VCO. Whenencoding the MSK/DTMF, the microphone input signal ismuted.6-2. Dceode■ QT/DQTThe output signal from the IF IC (IC401) enters the MCU(IC820) through IC812. IC820 determines whether or notthe QT or DQT matches the preset value, and controls theAFSW and speaker output sounds according to the squelchresults.■ 2-tonePart of the received AF signal output from the IF IC (IC401)passes through the baseband IC (IC812) goes to the otherAF amplifier IC808, is compared, and then goes to IC820.IC820 checks whether or not the 2-tone data is necessary. Ifit matches, IC820 carries out a specified operation, such asturning the speaker on.■ DTMF / MSKThe DTMF and MSK input signal from the IF IC (IC401)goes to IC812. The decoded information is then processedby the MCU.7. Power SupplyThere are five 5V power supplies and three 3.3V powersupplies: 50M, 50V, 50C, 50R, 50T, 33M, 33MS and 33B.50M and 33M are always output while the power is on.33MS is always output, but turns off when the power isturned off, to prevent malfunction of the MCU.50C is a common 5V and is output when SAVE is not setto ON.50R is 5V for reception and output during reception.50T is 5V for transmission and output during transmis-sion.50V is 5V for the SP/MIC connector.33B is 3.3V for the baseband IC (IC812).CIRCUIT DESCRIPTION / 电路说明■高速数据 (2- 音 )高速数据 (HSD) 从微处理器的针脚 3(HSDENC) 输出。信号通过低通 CR 滤波器。由微处理器进行调整的 TX 频偏被施加到基带 IC(IC812)。此信号与音频信号混合，然后送入 VCO 和 TCXO。■ MSK/DTMFMSK 和 DTMF 信号由基带 IC(IC812) 生成。MSK 信号从 IC812 的针脚 24 输出。此信号通过数模转换器，然后发送给 VCO。编码 MSK 和 DTMF 信号时，麦克风输入信号被静音。6-2. 解码■ QT/DQTIF IC(IC401) 的输出信号通过 IC812 送入微处理器(IC820)。IC820 确认 QT 或 DQT 是否与预设值匹配，控制AFSW，然后扬声器根据静噪结果输出声音。■ 2- 音部分接收的 AF 信号从 IF IC(IC401) 输出，然后通过基带IC(IC812) 送入另一个 AF 放大器 C808 进行比较，然后送入IC820。IC820 检查是否需要 2- 音数据。如果匹配，IC820 就执行特定的操作，如打开扬声器。■ DTMF/MSKIF IC(IC401) 的 DTMF 和 MSK 输入信号送入 IC812。然后由微处理器处理解码信息。7. 电源微处理器有 5 个 5V 电源和 2 个 3.3V 电源。电源打开时，50M 和 33M 总是输出。5M 总是输出，但电源关闭时 33MS 关闭，以防止微处理器出现故障。50C 是普通的 5V 电源，它在 SAVE 没有设为 ON 时输出。50R 是接收用 5V 电源，它在接收期间输出。50V 是 SP/MIC 用 5V 电源。33B 是基带 IC (IC812) 用 3.3V 电源。