Interfere with fm radio signal is fun, if you're bored or no work, you can do at home, where neighbors , at school , or even near the transmitter. With the circuit above you can interfere with the speech signal in condenser microphone , and the signal will be issued by the circuit will then be received by FM radio receiver and a voice that we remove it before going out mixed with the signals emitted by radio FM transmitter.
Part List :
R1 = 4K7R2 = 2K2C1 = 1n5C2 = 47pFC3 = 33pFL1 = Nikelin wire coil with a diameter 0,8 mm and 5mm in diameter wound coil 10 xT1 = 2N3906Mic= Condenser Microphone
If the circuit does not work on the errors may occur :
Installation of the opposite transistor , incorrect placement of components , less voltage, the voltage is too high , the microphone is broken, transistor is damaged , broken coil .
Please note this circuit can work and receive FM radio reciver at distance of about 500 meters. And not to much use , because the radio will be able to slam his own neighborhood because they can not listen to good radio . :) good Luck :)