uv920维修电器原理图

Twin Band Mobile Radio Service Manual简觉问回回尚尚是日印I Structure of FrequencyThis model uses twice frequency conversion.For UHF band,the 1st IF is 38.85MHz,and the 2nd IF is455KHz;For VHF band,the 1 IF is 29.95MHz,and the 2IF is 450KHZ.The 1st local oscillations isprovided by PLL circuit.PLL circuit is also produced the necessary transmitting frequencies(see ChartI).A,B,C,D frequency points of Chart I are as followings:ANTSP11st MIX38.85HHzMCF@38.395MHzANTRESWMIX IFAMPDETAudioAMPPLLrocessorFINALRIVESWPRESP2DRIVEU512TCXOIst MIX29.25MHzMCF☑cFU460ANTMICSWAMPAudioMIcProcessorAMPPLLPREDRIVECOTCXO14.4MHzTriplerAX2Chart IStructure ofBDFrequency(1)136174.995MHz165.250-204.245MHz400470.995MHz429.25-500.245MHz(2)136-174.995MHz165.250-204.245MHz450-520.995MHz479.25-550.245MHz(3)136-174.995MHz165.250-204.245MHz245-245.995MHz274.25-275.245MHz