FM TRANSMITTER 0,4 W

Power supply: 12-14 V stab., 100 mA
RF power: 400 mW
Impedance: 50-75 ohm
Frequency range: 87,5-108 MHz
Modulation: wideband FM

Schematic diagram

Parts list

Capacitors:
C1, C2, C12 - 100 pF (ceramic)
C3, C5 - 0,22 uF (electrolytic)
C4 - 1,8 nF (plastic)
C13, C16, C17, C19 - 1 nF (ceramic)
C8, C9 - 10 pF (ceramic)
C10 - 47 pF (ceramic)
C11 - 8,2 pF (ceramic)
C14 - 60 pF trimmer
C15 - 35 pF trimmer
C18, C7 - 100 nF (ceramic)
C20 - 470 uF (electrolytic, 16 V)

Coils:
(All coils are free-standing air-core types, wound of 0,7 mm Cu wire, 6 mm internal diameter.)
L1 - 4,5 coils
L2 - 9,5 coils
L3 - 4,5 coils

Resistors:
R1, R2 - 10 k pot.
R3 - 33 k
R4, R7, R12 - 10 k
R5, R11 - 470
R6 - 27 k
R8 - 22 k
R9 - 270
R10 - 100

Misc.:
D1 - BB409 (BB109G, BBY31) varicap
T1 - BC547C (BC548C, BC547B)
T2 - BFR91A (BFR96)
T3 - BFR96

Antenna
Power supply
3,5 mm jack
CD player, computer
6 V / 0,1 A bulb

PCB LAYOUT