The FM transmitter circuit is using NPN transistor 2N2222. The L1 and C1 producess necessary oscillations Q1.The collector capacity C4, R3 and R4 resistor performs the function of the output mix theaudio to stereo player or i-emitter resistor R2 Pod.The provides sufficient stability for circuit.It also limits the collector current increse the battery.
With this circuit compact FM adapter connected to the audio output of your cassette player or i pod words, you can listen to your favorite music on the car track is stereo.This doesnot handy if your car stereo has an auxiliary circuit outlet is not to buy a short-range FM transimitter.