QUANZHOUBAOJIE ELECTRONICS CO.,LTD. Model:BJ-9900
Version:BJ-9900-0812-V1 Page 3 of 75
CIRCUIT DESCRIPTION
Receiver signal channel
Main band 430MHZ Signal
430MHz signal transmits to Antenna through a high pass filter network, and a low pass
filter network switching diode D1029,D1030{}and }D1001, then transmit to Main band
RF amplifier Q1001 through another low pass filter network.
Amplified 430MHz signal transmits to Tuned vibration variable resistance filter
network through the switch D1002,which include D1004.D1005 ,D1006 and related
circuit. and then it transmits to the first mixer Q1003.Meanwhile UHF local oscillator
signal which comes from UHF-VCO/BQ1116 transmit to the first mixer Q1003 and
generate first IF of 38.55MHz main band.
Main band
144 MHz
signal
144MHz signal transmits to Antenna through a high pass filter network, and a low pass
filter network switching diode D1113,D1114,D1115, D1116 and D1117 then transmit to
Main band RF amplifier Q1014 through another low pass filiter network.Amplified
144MHz signal transmits to first mxier Q1016 through Tuned vibration variable
resistance filter network th including D1017.D1005 ,D1006 and related circuit.
Meanwhile VHF local oscillator signal which comes from VHF-VCO/BQ1120 transmit
to the first mixer Q1016 and generate first IF of 38.55MHz main band .
Main band IF and audio signal
