Kenwood NXR-800 Service Manual

Also see for NEXEDGE NXR-800: Brochure Instruction manual Instruction manual Instruction manual Instruction manual

Contents

NXR-800122-8. AVR circuitIC104, IC603, IC704, IC705, IC706, IC807, IC808, IC809and IC810 are AVR ICs.Each circuit contains its own power regulator IC to main-tain isolation between circuits.2-9. Other circuitsIn addition, IC701 is an EEPROM. The transmitter ad-justment data adjusted for each unit is written into the EE-PROM. If the unit is installed in another set, it is not nec-essary to adjust it again from the beginning, but only fine-tuning is necessary for each unit.The temperature sensor (IC804) monitors the tempera-ture of the transmitter unit (X56-312 A/3).The D/A converters (IC701 and IC802) converts the AGCsetting (D_PC) of the driver circuit and control voltage value(PWR_CONT, PWR_PRT) of the Final Unit (X45-382 A/5).The A/D converter (IC803) converts the transmitter unit(X56-312 A/3) temperature, VCO & VCXO control voltage(CVT, CVT-REF and CVT-MOD), Final Unit (X45-382 A/5)PA current(PA_CURR), fan current (FAN_CURR), detectionvoltage (FWD_PWR, RFL_PWR), etc.The shift register (IC703) controls each part of the trans-mitter unit (X56-312 A/3) based on serial data of the ControlUnit (X53-413).CN801VBATT +13.8V IC704IC809SWRipplefilterIC807IC706IC705 IC603IC104IC808 8V #18V #28V9VCN8078V #2OCXO9V’8V #18V #1’5V #15V #25V #33.3VIC810 3VFig. 8 AVR circuit3. Final unitThe RF final amplifier unit (X45-382 A/5) amplifies thetransmitter power to a specifi ed level.This unit consists of the following circuits:(1) Transmitter power module(2) High pass filter(3) Forward/Reflect power detector circuit(4) Antenna switch(5) Harmonic filter circuit(6) APC circuit(7) High temperature detector circuit(8) FAN action control circuit(9) Current detector circuit(10) AVR Circuit(11) Other Circuits3-1. Transmitter power moduleThe power module IC10 uses power module RA13H3340M131 to improve its efficiency. The driver output of thetransmitter unit passes through an attenuator and enters thepower module IC10 pin 1. Power module IC10 amplifi es theRF power according to the voltage at the amplifi cation con-trol pin 2 (VGG) and outputs it through pin 4 (Pout).RA13H3340M131a Pin b VGG c VDD d PoutFig. 9 Transmitter power moduleCIRCUIT DESCRIPTION