Stereo FM Transmitter
This is a small stereo FM transmitter. Output can be tuned from 88 to 108Mhz and the transmitter can be battery powered or be used with presented low voltage power supply. This circuit is based on the Rhom BA1404 datasheet. The maximum voltage should not exceed 3V. The IC can be driven from a 7805 Regulator with a couple of 1N4001 diodes to reduce the supply voltage to about 2.8 Volts. RF output power is typically 500mW but range depends upon antenna coupling and efficiency, environment and size of antenna. A small telescopic whip has an expected range of at leaset 100 metres or more.
Transmitter Parts List
R1,R2 27k
R3 5.6k
R4 150k
R5, R6 22k
R7 220R
C1 10uF
C2 220p
C3 1n
C4,C5 10u
C6,C7,C8, C9, C10 10p
C11, C13 1n
C12 10u
L1 3.5 turns 18 swg
XTAL1 38kHz Crystal Oscillator
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