Please I have succeeded in building an fm transmitter based on Tetsuo Kogawa's project. It works well but I would like to have an understanding of this circuit and the function of its components. All i know now is that it uses a colpitts oscillator.
The transistor Colpitts oscillator oscillates at a frequency in the FM broadcast band. It is tuned with the trimmer capacitor.
The audio input causes the transistor to conduct more and conduct less which changes its capacitance which changes its frequency producing AM plus FM. FM radios ignor the AM.