Kenwood NX-200 Service Manual

Also see for NEXEDGE NX-200: Brochure Instruction manual Instruction manual Specifications Instruction manual

NX-200(G)188. Signaling Circuit8-1. Encode (QT/DQT/LTR/DTMF/2-tone/MSK)Each signaling data signal of QT, DQT, LTR, DTMF,2-tone and MSK is generated by the DSP circuit, super-posed on a modulation signal and output from IC108. Themodulation balance of the QT/DQT/LTR signal is adjusted bythe D/A converter(IC703) and the resulting signal is routedto the modulation input of the VCO and VCXO (X1). Eachdeviation of the TX QT, DQT, LTR, DTMF, 2-tone and MSKtone is adjusted by changing the output level of IC108 andthe resulting signal is routed to the VCO and VCXO. The RXDTMF tone is routed to the receive audio signal system, andis output from the speaker.8-2. Decode (QT/DQT/LTR/DTMF/2-tone/MSK)The audio signal is removed from the FM detection signalsent to the DSP circuit and the resulting signal is decoded.9. Compander CircuitThe term “compander” means compressor and expander.The compander reduces noise by utilizing a compressorand an expander. The transceiver contains a DSP (IC102) toperform this operation. The transceiver compander can beturned on or off using the FPU.10. GPS CircuitThe GPS information function can be used by setting itthrough the FPU. When the GPS information function isenabled, the AVR (IC4/GPS) is enabled by the OPT5, and issupplied to the GPS circuit.The GPS circuit block consists of a TX-RX unit anda GPS unit (X58). The circuit from an antenna to LNA is ona TX-RX unit. This output is connected to the GPS unit bythe coaxial cable.The GPS signal of 1575.42MHz received with the an-tenna (with GPS band) is passed by the HPF and BPF (L605/TX-RX) and is amplified by the LNA (IC881/TX-RX).The GPS signal is processed by the GPS IC (IC1/GPS)and input to the ASIC (IC108/CONT) through the UART port.The ASIC (IC108/CONT) processes the GPS data (NMEA)and sends the resulting information to the LCD.The GPS IC operates in stand-alone. Operating voltageis 3.1V. When the transceiver power is off, the GPS IC willbe backed up with the internal coin battery. When the batterypack is removed, the GPS IC will be backed up for aboutone day in a coin battery. But if the GPS IC has never hadthe position fixed, it will not be backed up.When the GPS function is enabled, the consumption cur-rent increases by about 70 mA.CIRCUIT DESCRIPTIONFig. 8 Power supply circuitQ40550T SWQ40150R SWQ40250IF SWIC400AVR/SAVE/5TC5RCSBCCN40050R50IF+B50C50TRX circuitRF Final AMPAPCVCOTX circuitIF circuitIC402DC/DC150C Assist, TuneIC403DC/DC-10V LCD Bias31BU SRAM, RTCIC403AVR IC33C PLL, VCTCXOQ403SB3 SWSB3 TX/Busy LEDF4002.5AIC411AVR IC5UC 50U UniversalIC416AVR IC Q40931BUIC708AVR IC5A OptionQ403SB2 SWSBC SB2 BackLightKey Light33MSB1ASIC, DSP I/O,Flach, LCD DRVIC407DC/DC IC404AVRVOL SW15M ASIC, DSP coreIC717DC/DC33A/PSW/BINTASIC Analog,AudioIC406AVRIC414DetectQ408ANDD408ORD412ORQ402Lvl ConvIC108ASICQ401Lvl ConvCN404Control unit (X53)SBCTX-RX unit (X57)31VIC4AVR IC5A CN710CN10Sub (GPS) unit (X58)GPS moduleBufferV_BCKPLithium cell