Icom IC-R20 Service Manual - Page 64

11-8 DOWNCONV BOARD RF_IN GND 2.8V RF_IN GND RF_IN GND 2.2V C49 R30 0.01 180k R29 C47 1k 0.01 0.7V R20 10 R19 820 R32 C53 1k 0.01 R31 1k C48 0.01 C51 470p Q6 2SC5277 C50 C52 470p 470p IC4 MB15E03SL 1 2 3 4 5 6 7 8 OSCI OSCO VP VCC DO GND XFIN FIN R P L/F ZC PS LE DAT CLK 16 15 14 13 12 11 10 9 C18 470p R17 1k C26 0.1 +3V 2.8V PLLCK PLLDATA PLLESTB 2.8V R16 150 2.3V C17 470p R15 220 R14 C16 56k 470p C15 470p Q2 2SC5006 +3V +3S C23 4.7 R18 330 2.6V R10 47 C12 10 L3 0.82µH C19 470p C8 2p C22 C21 0.33 470p L6 D3 C13 0.22µH 1SV245 22p C40 R33 4p 1k L4 12nH Q1 2SC5006 C14 0.1 C10 1p C9 R7 2p 330 C11 C58 R8 R9 0.001 0.1 10k 4.7k Q3 R13 UNR911J 15 R12 10 R11 15 RF_IN GND OSC PLLCK PLLDATA PLLESTB GND IF_OUT 8 7 6 5 4 3 2 1 J1 to RF unit HJ10 +3S IF_OUT DOWN_CONV +3V +3S C37 R22 470p 4.7k D8 1SV308 D7 1SV308 C39 1p R23 4.7k Q5 XP1113 R27 C38 4.7k 470p 4 3 C54 C55 2 R25 R26 47p 47p 1k 1k 5 1 C34 470p L7 L8 1.5nH 6.8nH C35 470p R28 C36 10 2p R21 D6 27k 1SV308 C30 C29 2p 1p C32 22p L10 2.2nH C28 1p C31 12p L9 3.9nH D5 C27 1SV308 10p Q4 2SC5624 +3S +3V DOWN_CONV 2GLO 1GLO GND 6 5 4 3 2 1 J2 to RF unit HJ11 IF_OUT C43 470p R5 4.7k C4 C3 C2 8p 6p 8p D1 R4 1SV308 4.7k L2 L1 8.2nH 8.2nH C41 C42 15p 12p 1001 MHz or 2002 MHz LO DOWN_CONV 3V IC2 µPC2749TB 3 2 1 GND GND IN OUT GND VCC 4 5 6 2.4V C56 R2 47p 470 3 2 1 LO GND RFI PS VCC IFO 4 5 6 C1 10p IC3 µPC2757TB R1 180 [USA], [EUR] C6 470p C5 470p 2.8V 1.7V C44 470p C7 1p C45 3p L11 6.8nH C46 3p R6 4.7k D2 1SV308 R3 4.7k DOWNCONV BOARD Explanatory notes VOLTAGE LINE RF_IN 11 - 7