Easy to build high-quality PLL FM
transmitter with typical output power of 5 W and no-tune design. The transmitter includes RDS/SCA input and Audio/MPX input with optional pre-emphasis. It can be used with or without stereo encoder. Tuning over the FM band is provided by two buttons that control dual-speed PLL. The transmitter can work also without the LCD display. Some experience with building devices of this kind are highly recommended.
Q1 - BF240 Q2 - BFG135 (BFG235) Q3 - 2SC1971 (2N3553) + heatsink Q4 - BC547B D1 - SB260 (1N5822, 1N581x) D2, D3 - BBY40 (BBY31) D4 - LED 5mm U1 - 78L09 U2 - TSA5511 (TSA5512, SDA3202) in DIL socket U3 - PIC16F627A in DIL socket (programmed) U4 - 78L05 R1, R2, R11, R17, R20 - 10k R3, R21 - 270R R4, R15 - 33k R5, R7, R12, R13, R16 - 680R R6, R14 - 18k R8 - 47R (33R if Q2 is BFG235) R9 - 18R R10 - 4k7 R18 - 3k3 R19 - 100k smd 1206 R22 - 91R R23 - trimmer 5k mini C1, C4, C9, C12, C13, C14, C15, C30, C31, C32, C33, C35 - 10n smd 1206 (C) C2, C17, C20 - 15p (C) C3 - 10p (C) (15p if the PCB is single-sided) C5 - 1n (C) C6, C28, C29, C34 - 100u/10V (E) C7, C26 - 10u/35V (E) C8 - 22p (C) C10 - 47p (C) (33p if Q3 is 2N3553) C11, C27 - 100n (C) C16, C36 - 33p (C) C18 - cap. trimmer 50p C19 - 470u/16V (E) C21 - 4u7/50V (E) C22 - 330p (C) C23, C24 - 47p (C) C25 - 3n3 (P) L1 - 3.5 turns on 7 mm diameter L2 - 1uH/815mA choke, or about 10 turns of thin wire on mini ferrite core L3 - 2.5 turns on 6 mm diameter (4.5 turns if Q3 is 2N3553) L4, L5 - 3.5 turns on 6 mm diameter Y1 - crystal 6.4 MHz or 3.2 MHz TR1 - rf ferrite
transformer 2:1 (3:1 if Q3 is 2N3553), see text SW1, SW2 - button mini J1, J2, J3 - BNC connector 90 deg. J4 - power supply connector J5 - HD44780 LCD standard connector, 2x8 or 2x16 characters J6, J7 - jumper